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TRIPLEE FOUR- STROKE FOUR CYLINDER DIESEL ENGINE WITH MECHANICAL

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					M308.a; HEAT ENGINES LAB MANUAL



SNGCE/ME/HEL/LM/E308


                 DEPARTMENT OF MECHANICAL ENGINEERING

                                  LABORATORY MANUAL

                     E308.a; HEAT ENGINES LABORATORY

                                                                         0:0:2
                                                Name         Signature
              Prepared by           P.P. Binu

              Checked by            Prof. Koshy Varugheese

              Approved by           Dr. T. P. Lukose




      Sree Narayana Gurukulam College of Engineering
                    Kadayiruppu, Kolenchery- 682 311

                                                2003




DEPARTMENT OF MECHANICAL ENGINEERING
                                                  1
SNG COLLEGE OF ENGINEERING, KADAYIRIPPU
M308.a; HEAT ENGINES LAB MANUAL




                                    TABLE OF CONTENTS

                                                                             Page
   Sl.no.                           Description of experiment
                                                                              no.

                                                                             3
      1      Load Test on slow speed Diesel Engine
                                                                             8
      2      Load Test on Horizontal Diesel Engine
                                                                             12
      3      Load Test on Vertical Diesel Engine
                                                                             16
      4      Volumetric efficiency test on Vertical Diesel Engine
                                                                             18
      5      Load Test on Twin cylinder Diesel Engine
                                                                             23
      6      Load Test on 2S Petrol Engine
                                                                             25
      7      Load Test on 4S 4cylinder Petrol engine
                                                                             28
      8      Valve Timing Diagram of 4S Diesel Engine
                                                                             30
      9      Port Timing Diagram 2S Petrol Engine
                                                                             32
      10     Determination of COP of Air-conditioning system
                                                                             36
      11     Determination of COP of Refrigeration system
                                                                             39
      12     Performance test on single stage Reciprocating Air Compressor




DEPARTMENT OF MECHANICAL ENGINEERING
                                                2
SNG COLLEGE OF ENGINEERING, KADAYIRIPPU
M308.a; HEAT ENGINES LAB MANUAL




Ex. No: 1              LOAD TEST ON SINGLE CYLINDER SLOW SPEED
                       DIESEL ENGINE

OBJECTIVE

        To evaluate the performance of the given Engine

               i)      Total Fuel Consumption (TFC)
               ii)     Specific Fuel Consumption (SFC)
               iii)    Brake Horse Power (BHP)
               iv)     Indicated Horse Power (IHP)
               v)      Brake Thermal Efficiency (BTE )
               vi)     Indicated Thermal Efficiency (ITE)
               vii)    Mechanical Efficiency (ME)
               viii)   Brake Mean Effective Pressure (Bmep)
               ix)     Volumetric efficiency

     And to plot the performance curves.

ENGINE SPECIFICATION

        MAKE                           : FIELD MARSHAL
        BHP                            : 6.0
        SPEED                          : 660 RPM
        NO. OF CYLINDER                : ONE
        BORE                           : 114.3 mm
        STROKE                         : 139.7 mm
        ORIFICE DIA                    : 20 mm
        TYPE OF IGNITION               : COMPRESSION IGNITION
        METHOD OF LOADING              : ROPE BRAKE DYNAMOMETER
        METHOD OF STARTING             : HAND START
        METHOD OF COOLING              : WATER COOLED

BASICS

1.      Brake Power (BHP)

                                               2 NWR
                                       BHP 
                                                4500

                                  Where,   N -     Speed in RPM
                                           W=     W1 – S kg
                                           W1 –   wt added (including wt hanger) in kg
                                           S -    Spring balance reading in kg
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M308.a; HEAT ENGINES LAB MANUAL

                                             R = (D+d)/2
                                             D - Brake drum diameter
                                             D - Rope diameter

2.     Total Fuel consumption (TFC) in kg/hr.

                                                   10    3600
                                        TFC                     kg / hr
                                                      t 1000

                                  Where,      t - time for 10cc is volume of fuel consumption in s.
                                              ρ - Density (Diesel) in g/cc
                                             V = 0.838 g/cc

3.     Specific Fuel Consumption (SFC) in kg/BHP-hr.

                                                   TFC
                                           SFC        kg/ BHP-hr
                                                   BHP

4.     Brake Thermal Efficiency:

                                                      BHP  4500
                                         BTE                     100       %
                                                   (TFC )  CV  J
                                                        60

                                  Where, CV- calorific value of fuel (Diesel) in kcal/kg
                                      J    - Mechanical equivalent of heat
                                           = 427 kgf-m / kcal

5.     Indicated Horse Power (IHP)

       IHP can be calculated by Willans Line Graph method.


                                    TFC




                         FHP                                  BHP



                                        IHP = BHP + FHP
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M308.a; HEAT ENGINES LAB MANUAL


6.      Indicated Thermal Efficiency (ITE)
                                                         IHP  4500
                                             ITE                       100 %
                                                      (TFC )  CV  J
                                                           60
               Where,                      CV       - Calorific value of fuel (Diesel) in kcal/kg
                                           J        - Mechanical equivalent of heat
                                                    = 427 kgf-m / kcal

7.      Mechanical Efficiency (ME)

                                                      BHP
                                             ME         100     %
                                                      IHP



8. Brake mean effective pressure,

                                                    BHP  4500
                                           Bmep                   kg/ cm2
                                                    LA( N / 2)n

                                  Where,
                                           L - Stroke length in m,
                                           A - Bore area in cm2
                                           N- Speed in rpm,
                                           n - no. of cylinders

PROCEDURE

     1. Find the maximum load that can be applied to the engine using the engine details.
     2. Connect water inlet to a constant head water source.
     3. Switch on the cooling water supply to Engine Jacket and adjust it to suitable flow rate.
          (The flow rate can be measured by using the Rota meter).
     4. Connect the instrumentation power input plug to a 230V, single-phase power source. Now
         the digital temperature indicator displays the respective readings.
     5. Check the lubricating oil level in the sump with the dipstick provided.
     6. Check fuel level in the fuel tank and ensure the supply to engine.
     7. De-compress the engine by decompression lever provided near the fuel pump.
     8. Insert the starting handle and Crank the engine slowly by rotating in clockwise and ascertain
         proper flow of fuel into the pump and in turn through the nozzle into the engine cylinder.
         When maximum cranking speed is attained, pullout the decompression lever, now the engine
         starts. Allow the engine to run and stabilize. (Approximately 650 RPM. The engine is a
         constant Speed engine fitted with centrifugal governor).
     10. Open the cooling water gate valve and set it for required flow, Now load the engine by
         applying weights, load the engine in steps of ¼, ½, ¾, full load.



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M308.a; HEAT ENGINES LAB MANUAL

      11. Before taking the reading allow the engine to run at the set load and speed for few minutes.
          Note down the readings. Then increase the load by repeating the same procedure up to
          maximum load.
      12. To stop the engine after the experiment is over, remove all the weights applied, then push up
          the governor lever towards the engine cranking side and hold it till the engine stops and then
          close the cooling water gate valve.

                                Power      Time for 10 cc fuel             SFC
  Sl.          Load in kg
  No.
                                out put     consumption in s     TFC
                                                                         kg/BHP-
                                                                                   FHP   IHP   ηBTE   ηITE   ηME   Bmep
                                                                 kg/hr              hp    hp    %      %     %     kg/cm2
                                                                            hr
          W1       S        W    BHP        t1      t2      t

  1
  2
  3
  4
  5
  6


      MAXIMUM LOAD CALCULATION

                                                   2 NWR
                   Brake Power,           BHP 
                                                    4500

                                                   BHP  4500
                                           W                 kg
                                                    2 N  R

                            where,
                                                 W – Load in kg,

      RESULTS

      1. Maximum Brake Thermal Efficiency = …………………….%
      2. Maximum Indicated Thermal Efficiency = …………………%
      3. Maximum Mechanical Efficiency = …………………………%
      4.
         Maximum Brake Mean Effective Pressure = ………………kg/ cm2


      INFERENCE




DEPARTMENT OF MECHANICAL ENGINEERING
                                                                 6
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M308.a; HEAT ENGINES LAB MANUAL




Ex. No: 2              LOAD TEST ON FOUR STROKE SINGLE CYLINDER
                       HORIZONTAL DIESEL ENGINE
OBJECTIVE

   To conduct Load test on the given diesel E/N to determine
                  1. Total Fuel Consumption (TFC)
                  2. Specific Fuel Consumption (SFC)
                  3. Brake Horse Power (BHP)
                  4. Indicated Thermal Efficiency (IHP)
                  5. Brake Thermal Efficiency (BTE)
                  6. Indicated Thermal Efficiency (ITE)
                  7. Mechanical Efficiency (ME)
                  8. Brake Mean Effective Pressure (Bmep)

   And to plot,
                        1) BHP Vs TFC
                        2) BHP Vs SFC
                        3) BHP Vs ME
                        4) BHP Vs BTE
                        5) BHP Vs ITE
                        6) BHP Vs Bmep

ENGINE SPECIFICATION

MAKE                              : KIRLOSKAR
BHP                               : 5.0
SPEED                             : 1500 RPM
NO. OF CYLINDER                   : ONE
BORE                              : 92 mm
STROKE                            : 95 mm
ORIFICE DIA                       : 17 mm
COMPRESSION RATIO                 : 22:1
TYPE OF IGNITION                  : COMPRESSION IGNITION
METHOD OF LOADING                 : ROPE BRAKE DYNAMOMETER
METHOD OF STARTING                : HAND START
METHOD OF COOLING                 : WATER COOLED

BASICS

   1.   Brake Horse Power

                                          2 NWR
                                  BHP 
                                           4500


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M308.a; HEAT ENGINES LAB MANUAL

                       Where,               W= W1-S
                                            W1-Dead weight in kg       S - spring balance reading in kg
                                            R= (D+d)/2
                                                  D- Diameter of Brake drum in meters (300 mm)
                                                  d- Dia of rope in m (16 mm),
                                            N- Speed of the engine in rpm

     1.      Total Fuel Consumption (TFC)

                                            10  3600  
                                  TFC                          kg / hr
                                               t 1000

                                             Where, t - time for 10 cc of fuel consumption
                                                    - Density of diesel in g/cc

3.        Specific Fuel Consumption (SFC)

                                            TFC
                                   SFC               kg / BHP  hr
                                            BHP

4.        Indicated Horse Power (IHP)

                                   IHP  BHP  FHP

                                  FHP – Frictional Horse Power; obtained from BHP Vs TFC Graph
                                        (X-intercept of the graph)

5.        Brake Thermal Efficiency

                                               BHP  4500
                                   BTE                    100          %
                                            (TFC )  CV  J
                                                 60

                                   Where,           TFC - Total fuel consumption in kg/hr.
                                                    CV - Calorific value of Diesel (11000 kcal/kg)
                                                     J - Mechanical equivalent of heat (427 kgf-m/kcal)

6.        Indicated Thermal Efficiency

                                    IHP  4500
                        ITE                    100          %
                                 (TFC )  CV  J
                                      60

                                  Where,           TFC - Total fuel consumption in kg/hr.
                                                   CV - Calorific value of Diesel = 11000 kcal/kg
                                                     J - Mechanical equivalent of heat = 427 kgf-m/kcal


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M308.a; HEAT ENGINES LAB MANUAL

7.         Mechanical Efficiency
                                                          BHP
                                                 ME         100             %
                                                          IHP


8.         Brake Mean Effective Pressure

                                                           BHP  4500
                                                 Bmep                             kg / cm 2
                                                           LA( N / 2)n

                                                 Where,              L – Stroke length in m
                                                                     A – Bore area in cm2
                                                                     n – Number of cylinder

** N/2 is used since four stroke engine

      PROCEDURE

                    Initially find the maximum load that can be applied to the Engine.
           1).Connect the instrumentation power input plug to a 230 V single phase power source. Now
              the digital meter indicates the respective readings.
           2).Check the fuel supply to the engine.
           3). Check the lubricating oil level
           4). Switch on the cooling water supply
           5). Start the engine by cranking
           6). Now adjust throttle so that the engine to run at rated RPM = 1500
           7). Load the engine in order of ¼, ½, ¾ and Full Load.
           8). In each case note down the time for 10 cc of Fuel consumption
           9). Then with the details find the BHP and TFC plot the graph BHP Vs TFC and
                x- intercept of the curve (Willain’s Line) gives the Frictional Horse Power
                (FHP). Then BHP + FHP gives IHP.

OBSERVATIONS

                                 Power     Time for 10 cc fuel
     Sl.        Load in kg                                                 SFC
     No.
                                 out put   consumption in sec    TFC
                                                                         kg/BHP-
                                                                                    FHP    IHP   ηBTE   ηITE   ηME   Bmep
                                                                 kg/hr               hp     hp    %      %     %     kg/cm2
                                                                            hr
           W1       S        W    BHP       t1      t2      t

     1
     2
     3
     4
     5
     6




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M308.a; HEAT ENGINES LAB MANUAL



MAXIMUM LOAD CALCULATION

                                  2 NWR
  Brake Horse Power, BHP 
                                   4500

                        Where,        W= W1-S ………. kg
                                      D = 0.3 m ,        d = 0.016 m,   N=1500, rated rpm

                                  BHP  4500
                           W                =…………….kg
                                    2 NR

RESULTS

1. Maximum brake thermal efficiency =…………………………..
2. Maximum indicated thermal efficiency =………………………..
3. Maximum Mechanical efficiency =…………………………….
4. Brake mean effective pressure =………………………………..

INFERENCE




DEPARTMENT OF MECHANICAL ENGINEERING
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M308.a; HEAT ENGINES LAB MANUAL



Ex. NO: 3                         LOAD TEST ON FOUR STROKE SINGLE CYLINDER
                                  VERTICAL DIESEL ENGINE

OBJECTIVE

To conduct Load test on the given diesel E/N to determine

           1.   Total Fuel Consumption (TFC)
           2.   Specific Fuel Consumption (SFC)
           3.   Brake Horse Power (BHP)
           5.   Brake Thermal Efficiency (BTE)
           6.   Indicated Thermal Efficiency (ITE)
           7.   Mechanical Efficiency (ME)
           8.   Brake Mean Effective Pressure (Bmep)
And to plot,
                1) BHP Vs TFC
                2) BHP Vs SFC
                3) BHP Vs ME
                4) BHP Vs BTE
                5) BHP Vs ITE
                6) BHP Vs Bmep

ENGINE SPECIFICATION

       MAKE                               : KIRLOSKAR
       BHP                                : 5.0
       SPEED                              : 1500 RPM
       NO. OF CYLINDER                    : ONE
       BORE                               : 80 mm
       STROKE                             : 110 mm
       ORIFICE DIA                        : 17 mm
       COMPRESSION RATIO                  : 17.5 :1
       TYPE OF IGNITION                   : COMPRESSION IGNITION
       METHOD OF LOADING                  : ROPE BRAKE DYNAMOMETER
       METHOD OF STARTING                 : HAND START
       METHOD OF COOLING                  : WATER COOLED


BASICS

 1. Brake Horse Power (BHP)

                                          V I
                                  BHP          g
                                          736

                        Where,  V - volt meter reading
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M308.a; HEAT ENGINES LAB MANUAL

                                    I - Ammeter Reading,
                                   g - Generator Efficiency = 80 %

2. Total Fuel Consumption (TFC)

                                            10  3600  
                                  TFC                          kg/hr
                                               t 1000

                            Where, t - time for 10 cc of fuel consumption
                                   Density of diesel in gm/cc (0.838)

4. Specific Fuel Consumption (SFC)

                                             TFC
                                  SFC                  kg/BHP-hr
                                             BHP

5. Indicated Horse Power (IHP)

                                  IHP  BHP  FHP

                                  FHP – Frictional Horse Power; obtained from BHP Vs TFC Graph (X-
                                        intercept of the graph)

6. Brake Thermal Efficiency

                                                BHP  4500
                                    BTE                        100
                                             (TFC / 60)  CV  J

                        Where, TFC - Total fuel consumption in kg/hr.
                                CV – Calorific value of Diesel (11000 kcal/kg)
                                J - Mechanical equivalent of heat ( 427 kgf-m/kcal)

7. Indicated Thermal Efficiency

                                               IHP  4500
                                   ITE                        100
                                            (TFC / 60)  CV  J

               Where,             TFC - Total fuel consumption in kg/hr.
                                  CV - Calorific value of Diesel (11000 kcal/kg)
                                    J - Mechanical equivalent of heat (427 kgf-m/kcal)
8. Mechanical Efficiency

                                            BHP
                                  ME          100
                                            IHP



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M308.a; HEAT ENGINES LAB MANUAL



9. Brake Mean Effective Pressure (Bmep)

                                                  BHP  4500
                                         Bmep                             kg/cm2
                                                  LA( N / 2)n

                            Where,        N- Speed in rpm
                                         L – Stroke length in m
                                         A – Bore area in cm2
                                         n – Number of cylinder

** N/2 is used since four stroke engine

PROCEDURE

                  Initially find the maximum load that can be applied to the Engine.

1).Connect the instrumentation power input plug to a 230 V single phase power source. Now the
        digital meter indicates the respective readings.
2).Check the fuel supply to the engine.
3).Check the lubricating oil level
4).Switch on the cooling water supply
5).Ensure the MCB switch provided for engaging and disengaging the            loading
   systems should be in off position
6).Start the engine by cranking
7). Now the engine will run at rated RPM = 1500
8). Switch on the MCB on the resistance Bank and by operating cam switches
    provided on the load bank; Load the engine in order of ¼, ½, ¾ and Full Load.
9). In each case note down the time for 10 cc of Fuel consumption, Volt meter
    reading, Ammeter reading
10).Then with the details find the BHP and TFC plot the graph BHP Vs TFC and x-
     intercept of the curve (Willan’s Line) gives the Frictional Horse Power (FHP).
Then BHP + FHP gives IHP.

OBSERVATIONS

        Amm      Volt
  Sl.    eter   meter
                         Power     Time for 10 cc fuel             SFC
  No.   readi   readin
                         out put   consumption in sec
                                                         TFC
                                                                 kg/BHP-
                                                                            FHP     IHP   ηBTE   ηITE   ηME   Bmep
          ng     g in                                    kg/hr               hp      hp    %      %     %     kg/cm2
                                                                    hr
        amps     volts
           I      V       BHP       t1      t2      t
  1
  2
  3
  4
  5
  6



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M308.a; HEAT ENGINES LAB MANUAL




MAXIMUM LOAD CALCULATION

               Brake Horse Power;

                                                V I
                                      BHP            g
                                                736

                        Where,            V - Rated Voltage (230 V)
                                           I - Current
                                          g - Generator Efficiency = 80 %

                                                BHP  736
                                           I
                                                 V  g



RESULTS

1. Maximum brake thermal efficiency =…………………

2. Maximum indicated thermal efficiency =……………………

3. Maximum Mechanical efficiency =…………………………

4. Brake mean effective pressure =…………………………

INFERENCE




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M308.a; HEAT ENGINES LAB MANUAL



 Ex. No: 4               VOLUMETRIC EFFICIENCY TEST ON 4 STROKE
                         VERTICAL DIESEL ENGINES

OBJECTIVE

      To Find the Volumetric Efficiency of the Given Engine and to Plot the Variation of
Volumetric Efficiency with Load

BASICS

       The volumetric efficiency is the ratio between actual volumes of air intake to the theoretical
volume of air intake. Actual volume if found by measuring the volume flow rate by using an orifice
meter, but the theoretical volume or swept volume is found from the engine details.

1. Actual Volume of air drawn into the cylinder at RTP in m3/s

       a) Equivalent air column
                                              w
                                  ha  hw (       1)
                                              a

                       Where, hw- water column from differential manometer in m.
                               w - Density of water in kg/m3
                                a - Density of air in kg/m3

       b) Actual volume of air intake

                                   Va  Cd  Ao  2gha

                       Where, Cd - coefficient of discharge for the orifice
                             Ao - area of orifice in m2
                             G - Acceleration due to gravity in m/s2

2. Swept Volume/ Theoretical Volume

                                          LA( N / 2)n
                                   Vs                       m3 / s
                                              60
                                                              D2
                    Where,        A - Bore area in m2, A 
                                                               4
                                  D – Bore diameter in m
                                   L – Stroke length in m
                                  N - Speed in rpm
                                   n - no. of cylinders



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M308.a; HEAT ENGINES LAB MANUAL



3. Volumetric efficiency

                                           Va
                                  vol       100 %
                                           Vs

                                  Va – Actual volume of air in m3/s
                                  Vs – Swept volume of air m3/s

PROCEDURE

Initially find the maximum load that can be applied to the Engine.

1. Connect the instrumentation power input plug to a 230 V single phase power source. Now the
        digital meter indicates the respective readings.
2. Check the fuel supply to the engine.
3. Check the lubricating oil level
4. Switch on the cooling water supply
5. Ensure the MCB switch provided for engaging and disengaging the loading
   systems should be in off position
6. Start the engine by cranking
7. Now the engine will run at rated RPM = 1500
8. Switch on the MCB on the resistance Bank and by operating cam switches
    provided on the load bank; Load the engine in order of ¼, ½, ¾ and Full Load.
9. In each case note down the manometer reading h1 and h2 also voltmeter reading, Ammeter reading
10. Then with the details find the volumetric efficiency and plot the graph.


OBSERVATIONS

       Net load W                                                Equivalent air   Actual     Swept
Sl.                  BHP              Manometer reading                                               ηVol
         in kg                                                     column         volume    volume
No.
                                h1             h2          hw         ha
           W          hp                                                          Va m3/s   Vs m3/s   %
                              in cm          in cm        in m       in m




RESULT

The maximum value of volumetric efficiency = ……………….

INFERENCE



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                                                          16
SNG COLLEGE OF ENGINEERING, KADAYIRIPPU
M308.a; HEAT ENGINES LAB MANUAL




Ex. No: 5                         LOAD TEST ON 4S TWIN CYLINDER DIESEL
                                  ENGINE

OBJECTIVE

       To conduct load test on the given Diesel E/N and to find

                           1.     Total Fuel Consumption (TFC)
                           2.     Specific Fuel Consumption (SFC)
                           3.     Brake Horse Power (BHP)
                           4.     Indicated Horse Power (IHP)
                           5.     Brake Thermal Efficiency (BTE )
                           6.     Indicated Thermal Efficiency (ITE)
                           7.     Mechanical Efficiency (ME)
                           8.     Brake Mean Effective Pressure (Bmep)
                           9.     Volumetric efficiency


       And to plot the curves           BHP Vs TFC;      BHP Vs SFC;
                                        BHP Vs BTE ; BHP Vs ITE
                                        BHP Vs ME ; BHP Vs Bmep

ENGINE SPECIFICATION

MAKE                              : KIRLOSKAR
BHP                               : 10
SPEED                             : 1500 RPM
NO. OF CYLINDER                   : TWO
BORE                              : 87.5 mm
STROKE                            : 110 mm
ORIFICE DIA                       : 20 mm
TYPE OF IGNITION                  : COMPRESSION IGNITION
METHOD OF LOADING                 : EDDYCURRENT DYNAMOMETER
METHOD OF STARTING                : HAND START
METHOD OF COOLING                 : WATER COOLED

BASICS

1.     Brake Power (BHP)

                            2 NT
                BHP 
                        60 1000  0.75

               T = Torque in N-m
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M308.a; HEAT ENGINES LAB MANUAL



2.     Total fuel consumption (TFC) in kg/hr

                                  10    3600
                       TFC 
                                     t 1000


                   Where,         t- time for10cc fuel consumption in s.
                                  ρ –Density of Diesel in gm/cc

3.     Specific fuel consumption (SFC) in          Kg/BHP- hr

                                  TFC
                        SFC 
                                  BHP

4.     Indicated power; IHP = BHP + FHP

           IHP can be calculated by Willans Line Graph method.


                                     TFC




                         FHP                                 BHP



                       IHP = BHP + FHP

4.     Brake Thermal Efficiency          BTE
                                     BHP  4500
                        BTE                     100
                                  (TFC )  CV  J
                                       60

       Where CV- calorific value of fuel (Diesel) in kcal/kg
              J-Mechanical equivalent of heat = 427 kgf-m / kcal




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       5. Indicated Thermal Efficiency

                                                IHP  4500
                                    ITE                    100
                                             (TFC )  CV  J
                                                  60

          Where, CV-calorific value of fuel (Diesel) = 11000 kcal/kg
                 J- Mechanical equivalent of heat = 427 kgf-m / kcal

6.        Mechanical Efficiency Mech

                                             BHP
                                   ME          100
                                             IHP

7.        Actual Volume (Va) of air drawn into the cylinder at RTP in m3/s

                                              w
                                  ha  hw (       1)         m
                                              a

                                  ha   - Manometric head in meters of air
                                  hw   - Manometric head in meters of water.= h1 – h2
                                  ρw    - Density of water [ 1000 kg/ m3 ]
                                  ρa   - Density of air [ 1.293 kg/ m3 ]

                                  Va  Cd  A o  2gha m3 /s

                  Where,          Cd = 0.62
                                  Ao - Area of orifice in m
                                  g - Acceleration due to gravity [9.81 m/s2 ]

     8.   Swept Volume (Vs)

                                           LA( N / 2)n
                                  Vs                    m3 / sec
                                               60

                           Where, A        - Bore area in m2
                                  L        - Stroke length in m
                                  N         - speed in rpm
                                   n       - No. of cylinders

       * N/2 is for four stroke engine




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9. Volumetric efficiency

                                       Va
                                      Vol 
                                           100
                                       Vs
                           Where, Va - Actual Volume m3/s
                                  Vs - Swept Volume m3/s
10. Brake mean effective pressure


                                                   BHP  4500
                                          Bmep                  kg/ cm2
                                                   LA( N / 2)n

                        Where               L – Stroke length in m ,
                                            A – Bore area in cm2
                                            N – Speed in rpm,
                                             n- no. of cylinders
PROCEDURE

   1. Connect the cooling water inlet to a constant head water source.

   2. Set zero by pressing the arrow button at digital water flow indicator first and Open the inlet
      gate valves of the engine jacket to suitable flow rate by adjusting the gate valve which is
      provided before the flow meter.
   2. Connect the instrumentation power input plug to a 230V, single-phase power source. Now
          the digital temperature indicator displays the respective readings.

   3. Set zero by pressing the arrow button at digital fuel flow indicator first and fill up the Diesel
          into the tank.

   4. Check the lubricating oil level in the sump with the dipstick provided.

   5. Ensure that the Engine is in the no load condition

   6. Open the Diesel cock provided from the Diesel tank.

   7. Set the fuel flow indicator, water flow indicator & Air flow indicator to zero by pressing the
           arrow button.
   8. De-compress the engine by decompression lever provided on top of the engine (Lift the
           lever).
   12. Insert the starting handle and Crank the engine slowly by rotating in clockwise and ascertain
      proper flow of fuel into the pump and in turn through the nozzle into the engine cylinder
      When maximum cranking speed is attained, Pull down the decompression lever, now the
      engine starts. Allow the engine to run and stabilize. The engine is a constant Speed engine
      fitted with centrifugal governor.



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   13. Now turn the knob of eddy current drive provided at the panel gradually to load the engine
       through eddy current dynamometer. The torque ‘T’ is indicated on a digital indicator. Now
       rotate the knob of eddy current drive in clockwise and set the load to ¼ of the full load.

   14. Before taking the reading allow the engine to run at the set load and speed for few minutes.
       Note down the readings. Time for 10 cc of fuel consumption and load on the Engine and
       difference of water column level in manometer for finding volumetric efficiency. Then
       increase the load and repeat the same procedure up to maximum load.

   15. To get the readings from the computer click start test, view file and give the file name, then
       view report. To take print out click print report.

   16. To stop the engine after the experiment is over pull the governor lever towards the engine
       cranking side.


   OBSERVATIONS


                               Time for 10 cc fuel
              Torq   Power
        Sl.                     consumption in s               SFC
        No.
                ue   out put                         TFC
                                                             kg/BHP-
                                                                       FHP   IHP   ηBTE   ηITE   ηME   Bmep
              N-m                                    kg/hr              hp    hp    %      %     %     kg/cm2
                                t1      t2      t               hr
               ‘T’    BHP

         1
         2
         3
         4
         5
         6




RESULTS

   1.   Maximum Brake thermal Efficiency = …………..%
   2.   Maximum Indicated Themal Efficiency = ……………%
   3.   Maximum Machanical efficiency = ……………….%
   4.   Maximum Volumetric efficiency = ………………..%
   5.
        Maximum Brake mean effective pressure = ………..kg/cm2


INFERENCE




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                                                              21
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Ex. No: 6      LOAD TEST ON TWO-STROKE PETROL ENGINE

OBJECTIVE
         To determine the total fuel consumption, brake horse power, brake thermal efficiency and
    brake mean effective pressure and to plot the following graphs.

       1. BHP Vs BTE
       2. BHP Vs Bmep
       3. BHP Vs TFC

ENGINE DETAILS

        1.   BHP = 2.5 ,
        2.   Rated rpm = 2800,
        3.   Stroke = 57 mm
        4.   Bore= 57 mm

BASICS

(1). Brake Horse Power

                                          2 N (W1  S ) R
                                  BHP 
                                              4500

                        Where,      N -rated rpm
                                   W1 - load in kg
                                    S- spring balance reading in kg
                                    R - Effective radius of brake drum in meters

(2). Total fuel consumption (TFC)

                                   10  3600  
                           TFC                              kg/hr
                                      t 1000

                        Where,
                             t - time in sec for 10 cc of fuel consumption
                              - Density of petrol in gm/cc

(3) Specific Fuel Consumption (SFC)

                        TFC
                SFC                kg/ BHP-hr
                        BHP



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(4) Brake mean effective pressure (Bmep)

                                               BHP  4500
                                   Bmep                               kg /cm2
                                                 LAN

                                    L - Stroke length in m
                                    A- Bore area in cm2
                                    N - speed in RPM

(5) Brake Thermal Efficiency (BTE)

                                             BHP  4500
                                    BTE 
                                         (TFC / 60)  CV  J
                                   TFC- Total fuel consumption in kg/hr.
                                   CV- Calorific value of petrol (10500 kcal/kg)
                                    J - Mechanical equivalent of heat (427 kgf-m/kcal)
PROCEDURE

                   Initially find the maximum Load
             1)   Connect the instrumentation power input plug to a 230 V single-phase power source.
                  Now the digital meter indicates the respective readings.
             2)   Check the fuel supply to the engine.
             3)   Check the lubricating oil level in the oil sump
             4)   Start the engine with the help of kick start
             5)   Now run the engine at rated rpm by adjusting the throttle; take the time for 10 cc of
                  fuel consumption.
             6)   Now Switch on the cooling water supply to brake drum
             7)   And load the engine to W = W1-S = 2,4,6 kg and in each case take the time for 10 cc
                  of fuel consumption after adjusting the machine to rated rpm.
             8)   Then with the details find the BHP, TFC, BTE, and Bmep and plot the graphs.

                                     Power       Time for 10 cc fuel              SFC
       Sl.        Load in kg
       No.
                                     out put     consumption in sec      TFC               ηBTE   Bmep
                                                                         kg/hr   kg/BHP-    %     kg/cm2
                                                  t1      t2
             W1      S         W      BHP                        T                  hr

        1
        2
        3
        4
        5
        6


RESULTS

       1. Maximum brake thermal efficiency = …………%
       2. Brake mean effective pressure = ………….kg/cm2


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INFERENCE




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                                          24
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EXPT. NO: 7                       LOAD TEST ON 4 STROKE 4 CYLINDER PETROL
                                  ENGINE


OBJECTIVE

To conduct performance test on the engine and to
   1. Total Fuel Consumption (TFC)
   2. Specific Fuel Consumption (SFC)
   3. Brake Horse Power (BHP)
   4. Brake Thermal Efficiency (BTE)
   5. Brake Mean Effective Pressure (Bmep)

ENGINE SPECIFICATION

       MAKE                           : HM (ISUZU)
       BHP                            : 10 (Derated)
       SPEED                          : 1500 RPM (Derated)
       NO. OF CYLINDER                : FOUR
       BORE                           : 84 mm
       STROKE                         : 82 mm
       ORIFICE DIA                    : 25 mm
       TYPE OF IGNITION               : SPARK IGNITION
       METHOD OF LOADING              : HYDRAULIC DYNAMOMETER
       METHOD OF STARTING             : SELF START
       METHOD OF COOLING              : WATER COOLED

BASICS

1.     Brake Power

                                                 W N
                                      BHP                      hp
                                                 2000

                                            W - load in kg
                                            N - speed in rpm
2.     Total fuel consumption

                                                10  3600  
                                      TFC 
                                                   t 1000

                                          Where, t- time for 10 cc fuel consumption in s.
                                          Density of fuel (Petrol) is 0.780 gm/cc



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3.      Specific fuel consumption (SFC)

                                            TFC
                                  SFC                       kg/BHP-hr
                                            BHP

4.      Brake Thermal Efficiency

                                               BHP  4500
                                   BTE 
                                            (TFC / 60)  CV  J

                       Where, CV – calorific value of petrol in kcal/kg
                                J – Mechanical equivalent of heat = 427 kg-m/kcal

5.      Brake mean effective pressure

                                     BHP  4500
                                  Bmep                 kg/ cm2
                                      LA( N / 2)n
                            Where        L – stroke length in m,
                                        A – bore area in cm2
                                         N – Speed in rpm,
                                           n- no. of cylinders (4)
                 ** N/2 is because 4S engine

PROCEDURE

     1. Find the maximum load that can be applied to the engine using the engine details.
     2. Connect water inlet to a constant head water source.
     3. Switch on the cooling water supply to Engine Jacket and adjust it to suitable flow rate.
         (The flow rate can be measured by using the Rota meter).

     4. Connect the instrumentation power input plug to a 230V, single-phase power source. Now
        the digital temperature indicator displays the respective readings.
     5. Connect the battery terminals to a well-charged 12 V battery with the terminals marked (+) (-)
        respectively to the engine cable terminals.
     6. Check the lubricating oil level in the sump with the dipstick provided.
     7. Check fuel (petrol)level in the fuel tank and open the Petrol cock provided underneath the
        Petrol tank and. Also ensure the accelerator knob is in cut off position (idle condition).
     8. Insert the ignition key into the starter switch and turn in clockwise, engage the clutch lever
        [disconnect the dynamometer]. Turn the key further clockwise to start the engine. Now the
        engine is running at idle speed. (Approx. 750 - 1000 RPM).
     9. Increase the speed by turning the accelerator knob clockwise until the speed reaches approx.
        1500 RPM.

     10. Now put the dead weight provided with hydraulic dynamometer at the back side and coincide
         the pointers provided at the bottom of the dial balance. Open the dynamometer hand wheel

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       gradually to load the engine through hydraulic dynamometer. The load is indicated on a
       dial type spring balance in terms of kg. The engine brake power is given by W x N /2000
       where ‘W’ is the load indicated on the spring balance and ‘N’ is the speed of engine. Now the
       engine speed decreases due to the application of load. Operate the acceleration
       knob simultaneously with the hydraulic dynamometer hand wheel and set the load to ¼ of the
       full load i.e. 3.5 kg [approx.] on the spring balance.

   11. Before taking the reading keep the dynamometer casing horizontal [coincide the pointer]
      by adjusting the hand wheel which is provided at the top of the dial balance and bring the
      engine speed to 1500 RPM. Allow the engine to run at the set load and speed for few minutes.
      Note down the readings. Then increase the load by repeating the same procedure up to
      maximum load i.e. : 13.5 kg.

OBSERVATIONS

                                                Time for 10 cc fuel              SFC
               Sl.   Load    Speed    Power
               No.   in kg   in rpm   out put
                                                 consumption in s      TFC in             ηBTE   Bmep
                                                                        kg/hr   kg/BHP-    %     kg/cm2
                      ‘W’      ‘N’    ‘BHP’      t1      t2
                                                                   t               hr

                1
                2
                3
                4
                5
                6




RESULTS

   1. Maximum Brake Thermal Efficiency = ……………………….%
   2.
      Maximum Brake Mean Effective Pressure = ………………….kg/cm2

INFERENCE




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                                                              27
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Ex. No: 8                 VALVE TIMING DIAGRAM OF 4S VERTICAL DIESEL
                          ENGINE


OBJECTIVE

To plot the valve timing diagram using the given cut model of 4S single cylinder diesel engine and to
find
          i)   Period of operation of inlet valve
          ii) Period of operation of exhaust valve
          iii) Fuel injection period
          iv) Scavenging period

BASICS

       Perimeter of the flywheel (P)

                                  P  2 R

                                         P
                       Radius, R 
                                        2

Arc length measured along the surface of the flywheel corresponds to the operation of the valve be
‘L’ ,

                                           L 180
               Angle subtended,                      rad
                                           R 


Angle corresponds to scavenging period = Angle corresponds to the operation of Inlet Valve before
TDC + Angle Corresponds to the operation of exhaust valve after TDC

Angle corresponds to Fuel Injection period = Angle corresponds to the operation of fuel Valve before
TDC + Angle Corresponds to the operation of fuel valve after TDC


                                       2 N
           Angular velocity ,  
                                        60

                                       
                                  
                                       t

               t- time period in sec, θ – crank angle

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                                       60  
                                  t
                                       2 N

PROCEDURE

        Rotate the flywheel in proper direction and mark the position of top dead centre(TDC),
Bottom Dead Centre(BDC). Then mark the position of the opening and closing of the valves ie: IVO-
inlet valve opening, IVC- inlet valve closing, EVO- Exhaust valve opening, EVC- Exhaust valve
closing, FVO- Fuel valve opening, FVC- Fuel valve closing.
        Then measure the arc length along the periphery of the flywheel and calculate the
corresponding angle.
        Then plot the valve timing diagram using the details.

OBSERVATIONS


  Name of the valve        Location             Corresponding arc   Angle in Degrees
                                                length from
                                                reference in cm

  IVO                      Before TDC


  IVC                      After BDC


  EVO                      Before BDC


  EVC                      After TDC


  FVO                      Before TDC


  FVC                      After TDC




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Ex. No: 9                         PORT TIMING DIAGRAM OF 2 STROKE PETROL
                                  ENGINE
OBJECTIVE

To plot the PORT timing diagram using the given cut model of 2S single cylinder petrol engine and
to find
              1. Period of operation of inlet port
              2. Period of operation of exhaust port
              3. Scavenging period

BASICS

       Perimeter of the flywheel,     P  2 R

                                             P
       Radius of the flywheel,        R
                                            2

Arc length measured along the surface of the flywheel corresponds to the operation of the valve be
‘L’,

                                           L 180
               Angle subtended,                   rad
                                           R 


Angle corresponds to scavenging period = Angle corresponds to Transfer PORT open to Exhaust
PORT closed

                                            2 N
           Angular velocity,          
                                             60

                                           
                                      
                                            t

                       Where, t- time period in sec, θ – crank angle

                                           60  
                                      t
                                           2 N
PROCEDURE

        Rotate the flywheel in proper direction and mark the position of top dead centre(TDC),
Bottom Dead Centre(BDC). Then mark the position of the opening and closing of the ports ie: IPO-
inlet port opening, IPC- inlet port closing, EPO- Exhaust port opening, EPC- Exhaust port closing,
Then measure the arc length along the periphery of the flywheel and calculate the corresponding
angle. Then plot the port timing diagram using the details.
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OBSERVATIONS


  Name of the valve        Location               Corresponding arc   Angle in Degrees
                                                  length from
                                                  reference in cm

  IPO


  IPC


  EPO


  EPC




RESULTS

         1. Period of operation of inlet port          =…………..s
         2. Period of operation of exhaust port        =…………..s
         3. Scavenging period                          =…………..s

INFERENCE




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Ex. No. 10         DETERMINATION OF COP OF THE GIVEN
                   AIRCONDITIONING SYSTEM

OBJECTIVE

To conduct Performance Test on Air Conditioner and to find out the Relative coefficient of
Performance.


EQUIPMENT

The given A/C (duct type)
       Refrigerant –R22.

BASICS

        The purpose of Air-Conditioning is to supply sufficient volume of clean air containing a
specific amount of water vapour and at a temperature capable of maintaining pre- determined
atmospheric conditions.
The system works on vapour compression refrigeration cycle.

                                          Refrigeration effect
        Theoretical COP              =
                                              Work done

                                           h1 -h 4
                                     =
                                           h 2 -h1


                where,      h1       - Enthalpy corresponding to P1 and T1
                            h2       -      Enthalpy corresponding to P2 and T2
                            h4       -     Enthalpy corresponding to P1 and T4
                    P1 and T1        -     Pressure and temperature of Refrigerant at inlet of compressor
                    P2 and T2            - Pressure and temperature of Refrigerant at exit of compressor
                           T3            - Temperature of Refrigerant at the exit of condenser.


          Actual COP = Q
                                 W

                  where,        Q - Refrigeration effect, and
                                W - Compressor input

                                  Actual COP
         Relative COP =
                                Theoretical COP

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PSYCHROMETRIC PROCESS

Cooling and Humidification:

         Adding of water vapour to the air is known as humidification. This is done by adding steam to
         the air at the inlet of cooling coil. When air is passed through a spray chamber part of the
         water will be evaporated and is carried with the air, thus increasing the specific humidity.

PROCEDURE

   1. Plug in the mains card of the system
   2. Switch - On the DP switch so that the digital panel meters indicates corresponding readings.
   3. Switch On the condenser fan and the blower
   4. Start the system by switching on the thermostat by opening the corresponding valves depending
      on solenoid and thermostatic expansion valve or capillary expansion device.
   5. Allow air flow through the air conditioning chamber and let it stabilize for few minutes.
   6. Record T1, T2, T3, P1, P2, V,I and Rota meter reading. Note down wet and dry bulb
      temperature at inlet and outlet also.

   Psychrometric process (Cooling and Humidification):

    1.   Fill the water in the boiler to about half to ¾ th and close the valve.
    2.   Switch on the boiler for about 45 to 60 minutes.
    3.   When steam is formed open steam inlet valve and allow it to flow about 10 minutes.
    4.   Record wet and dry bulb temperature at inlet and outlet.
    5.   Switch off boiler and after about 5 minutes switch off CF, EF and Mains.



                                              1        2




          Evaporator                                                             Condenser
                                             Compressor




                                           Expansion Valve
                                           VVALVEDevice
                       Block Diagram of Vapour Compression Cycle


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OBSERVATIONS

                                                                   Temp at inlet of     Temp. at exit of
                                                        V* I
                                                C                   Co
       Pressure     Pressure at     Voltag              (W)
                                              urrent,                                                      Ambient   Rotamet
Sl.   at inlet of     inlet of       e, V
                                                 I
                                                                   mpr                Con
No    compress      condenser                                              Conde               Expansi      Temp       er
                                                                   esso               dens                  T50 C    Reading
      or P1(psi)      P2(psi)        (v)                                    nser               on Valve
                                               (A)                   r                 er
                                                                           T20 C                 T40 C
                                                                    T10               T30 C
                                                                    C




CALCULATION

                                                                    h1 - h 4
                                    Theoretical COP            =
                                                                    h 2 - h1


                                  From R-22 p-h chart


                                             where,       h1 - Enthalpy corresponding to P1 and T1
                                                           h 2 - Enthalpy corresponding to P2 and T2
                                                           h 4 - Enthalpy corresponding to P2 and T3


                                                                           Refrigeration effect
                                              Actual COP =
                                                                            Compressor input

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                            Refrigeration Effect      =       m a c pa  Ti -To  kJ
                                       where, m a      - mass of air in kg.
                                                       - velocity of air × area of flow × density of air.
                    We can find out velocity of air by using Anemometer.
                                                   c Pa - Specific heat of air = 1.005kJ/kg K
                                                     Ti - Air inlet temperature.
                                                     To - Air outlet temperature from duct.
                                    Density of air        = 1.97 kg/m3 .
                                                            VxI
                                  Compressor input        =        kJ
                                                            1000
                                                             Actual COP
                                    Relative COP          =
                                                            Theortical COP

RESULT

  Theoretical COP of air conditioner          =
  Actual COP of air conditioner               =
  Relative COP of air conditioner             =


INFERENCE




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Ex. No.11           DETERMINATION OF COP OF THE REFRIGERATION
                    TEST RIG


OBJECTIVE

   To determine the Relative COP of the given Refrigeration System.

EQUIPMENT

The given Refrigeration Test Rig with refrigerant R-12.

BASICS

The system works on vapour compression refrigeration cycle.

                            Refrigeration effect
       Theoretical COP =
                                Work done
                                h1 - h 4
                          =
                                 h 2 - h1
               where h1 - Enthalpy corresponding to P1 and T1
                       h 2 - Enthalpy corresponding to P2 and T2
                       h 4 - Enthalpy corresponding to P2 and T3
                P1 and T1 - Pressure and Temperature of Refrigerant at inlet of compressor
                P2 and T2 - Pressure and Temperature of Refrigerant at exit of compressor
                     T3 - Temperature of Refrigerant at the exit of condenser.
                                Heat removed
           Actual COP =
                              Actual work input
           Heat removed = mcp dT
                        m - mass of water taken in the chiller in kg
                        cp - specific heat of water
                        dt - drop in temperature of water
        Actual work input = (E1 - E 2 ) 3600 kJ
                        E1 - Initial energy metre reading in kWh
                        E2 - final energy metre reading in kWh


                                    Actual COP
          Relative COP      =
                                  Theoritical COP

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PROCEDURE

   1   Fill the chiller with water
   2   Switch- On the power
   3   Start the system by switching on the thermostat by opening the corresponding valves
       depending on solenoid and thermostatic expansion valve or capillary expansion device.
   4   Note down the initial energy meter reading E1
   5   RecordT1, T2, T3, T4, P1, P2, V,I and Rotameter reading.
   6   Note down the initial temperature of water Ti
   7   After 30 minutes note down the energy meter reading E2 and Temperature of chilled water Tf

OBSERVATIONS

                                  Pressure
 Initial    Initial      Final                 Pressure        Temp at     Temp at    Temp at     Temp at
                                   at Inlet                                                                    Final
temp of    Energy      Energy                     in           inlet of   outlet of   outlet of   outlet of
                                      of                                                                      Temp of
water in     meter       meter                 Condense        Compre     Compress    Condense    Expansio
                                  compres                                                                      water
chiller,   reading     reading                     r             ssor        or           r       n valve.
                                     sor                                                                         Tf
    Ti        E1          E2                      P2              T1         T2          T3          T4
                                      P1                                                                        (0C)
  (0 C)     (kWh)       (kWh)                    (Psi)           (0C)       (0C)        (0C)        (0C)
                                    (Psi)




CALCULATION

                                        Refrigeration effect
                 Theoretical COP =
                                            Work done

                                              h1 - h 4
                                    =
                                               h 2 - h1


                          where, h1 - Enthalpy corresponding to P1 and T1
                                  h 2 - Enthalpy corresponding to P2 and T2
                                  h 4 - Enthalpy corresponding to P2 and T3
                           P1 and T1 - Pressure and Temperature of Refrigerant at inlet of compressor
                           P2 and T2 - Pressure and Temperature of Refrigerant at exit of compressor
                                   T3 - Temperature of Refrigerant at the exit of condenser.



DEPARTMENT OF MECHANICAL ENGINEERING
                                                          37
SNG COLLEGE OF ENGINEERING, KADAYIRIPPU
M308.a; HEAT ENGINES LAB MANUAL




                                     Heat removed
                 Actual COP       =
                                  Actual work input
                 Heat removed = mCp dT
                              m - mass of water taken in the chiller in kg
                              Cp - specific heat of water
                            dt - drop in temperature of water
             Actual work input = (E1 - E 2 ) 3600 kJ
                              E1 - Initial energy metre reading in kWh
                             E 2 - final energy metre reading in kWh
                                       Actual COP
                  Relative COP =
                                     Theoritical COP


RESULTS

  Theoretical COP of air conditioner          =
  Actual COP of air conditioner               =
  Relative COP of air conditioner             =

INFERENCE




DEPARTMENT OF MECHANICAL ENGINEERING
                                                   38
SNG COLLEGE OF ENGINEERING, KADAYIRIPPU
M308.a; HEAT ENGINES LAB MANUAL




 Ex. No. 12 PERFORMANCE TEST ON SINGLE STAGE RECIPROCATING
            AIR COMPRESSOR
OBJECTIVE

To study the variation of volumetric efficiency and isothermal efficiency of single stage air
compressor against various discharge values.

EQUIPMENT

Single stage air compressor Test Rig, Stop watch.

BASICS

1. Volumetric efficiency = Actual volume of air intake / theoretical volume

       Theoretical volume

                                           LAN
                                  v TH =         m3 /s
                                            60


                   Where,     L- stroke length – 60 mm
                              A-Bore area- (bore= 70 mm)
                              N - Speed in RPM – 1000

     Actual Volume (Va)
                                  Va = C d x ax 2gha           m3/s


                                            Where, Cd - Co- efficient of discharge of orifice. – 0.62
                                                    A - Cross sectional area of orifice (d=17mm).
                                                    ha - pressure in terms of m of air.

                                             g = 9.8 m/s2

                                             Va
                                  ηvol =         x100               %
                                             Vth
                                                       ρw
                                  ha =hw x               -1    
                                                       ρa

                                  w= 1000 kg/m3 , a = 1.17 kg/m3

2. Isothermal efficiency iso = isothermal work input/ Actual work input x 100

DEPARTMENT OF MECHANICAL ENGINEERING
                                                          39
SNG COLLEGE OF ENGINEERING, KADAYIRIPPU
M308.a; HEAT ENGINES LAB MANUAL



                                                             Pa +Pd
                        Isothermal work = Pa x Va x ln               
                                                               Pa

                                  Where, Pd - delivery pressure in kg/m2
                                         Pa - Ambient pressure in kg/m2 (1.051x 104 )
                                         Va - actual volume of air intake in m3 /s.

                                           Pa +Pd
                                                  = γ, compression ratio
                                              Pa



The value of isothermal work so obtained is kg-m / sec. Is converted to kW.


                Actual work input       = ηo xElectric power input
                                                  n x 3600
                                       = ηo x
                                                    tx K



                                  where,    t - time in sec for n no. of revolutions of energy meter disc.
                                            K- Energy meter constant in rev/ kWh.

PROCEDURE

        Close the outlet from the reservoir and then start the compressor. Then compressed air is
stored in tank. Wait till the pressure inside the chamber reaches 8 kg/cm2. Then open the outlet valve
and by fine adjustment make air inlet pressure and chamber pressure are equal. Then take reading on
U- tube manometer (level difference) and time for 5 rev of energy meter disc.
        By using the head difference obtained from manometer we will obtain the air discharge. By
using energy meter disc revolution input power can be calculated. Find the respective values and plot
the curves Pd Vs o and Pd Vs iso

OBSERVATIONS




DEPARTMENT OF MECHANICAL ENGINEERING
                                                      40
SNG COLLEGE OF ENGINEERING, KADAYIRIPPU
                                                                                                                                               Sl.No.
                                                                                                                                               Delivery pressure
                                                                                                                                               ‘Pd’ in kg/cm2




                                                                                                                                    RESULTS
                                                                                                                                               Delivery pressure




                                          INFERENCE
                                                                                                                                               ‘Pd’ in kg/m2

                                                                                                                                               Compression ratio
                                                                                                                                              h1



                                                                                                                                                   Differntial
                                                                                                                                                                       M308.a; HEAT ENGINES LAB MANUAL




                                                                                                                                                   manometer
                                                                                                                                                   reading
                                                                                                                                              h2




DEPARTMENT OF MECHANICAL ENGINEERING
SNG COLLEGE OF ENGINEERING, KADAYIRIPPU
                                                                                                                                                   Height of water
                                                                                                                                              hw




                                                                                                                                                   column in ‘m’
                                                                                                                                              ha




                                                                                                                                                   Equivalent air
                                                                                                                                                   column in m




                                 41
                                                                                                                                              t1




                                                                                                                                                   Time for n=3
                                                                                                                                              t2




                                                                                                                                                   revolutions of
                                                                                                                                                   E/M disc
                                                                                                                                              t




                                                                                                                                               Actual volume ‘Va’
                                                                                                                                               m3/s

                                                                                                                                               Theoretical    volume
                                                                                                                                                     3
                                                      2. Isothermal efficiency of the given reciprocating air compressor = ……….




                                                                                                                                               Vth, m /s
                                                      1. Volumetric efficiency of the given reciprocating air compressor = …………….




                                                                                                                                               Actual work done

                                                                                                                                               Isothermal work done


                                                                                                                                               Volumetric efficiency

                                                                                                                                               Isothermal efficiency

				
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