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					Paper EA1 – Energy Auditor – Set A Solutions

NATIONAL CERTIFICATION EXAMINATION 2004
FOR ENERGY AUDITORS
PAPER – EA1: GENERAL ASPECTS OF ENERGY MANAGEMENT & ENERGY AUDIT Date: 22.05.2004 Timings: 0930-1230 HRS Duration: 3 HRS Max. Marks: 150

General instructions: o o o o o Please check that this question paper contains 7 printed pages Please check that this question paper contains 65 questions The question paper is divided into three sections All questions in all three sections are compulsory All parts of a question should be answered at one place

Section – I: OBJECTIVE TYPE
(i) (ii) (iii)

Marks: 50 x 1 = 50

Answer all 50 questions Each question carries one mark Put a () tick mark in the appropriate box in the answer book

1.

India’s share of the world’s total primary energy consumption in 2002 was a) 2.1% b) 3.5% c) 5.4% d) 10.6%

2.

The second major commercial energy consuming sector in the country is a) Industry b) Agriculture c) Residential d) Transport

3.

Non-commercial energy is a) not available in the market b) no definite price set d) always ignored in energy accounting c) always traded for free

4.

If Rs. 1 Crore = US$ 200,000, then the annual current oil import bill of India is around a) 1.6 Billion US$ b) 12 Billion US$ c) 16 Billion US$ d) 4 Billion US$

5.

If the total installed power capacity in India was 100,000 MW at the beginning of 2001 and is increased annually by 7%, then the installed capacity requirement 10 years later will be a) 215,804 MW b) 183,846 MW c) 210,485 MW d) 196,715 MW

6.

A person can do the following with solar energy a) destroy it b) convert it c) create it d) burn it

7.

Select the source of stored mechanical energy a) compressed spring b) electricity c) water stored in reservoir d) coal

_________________________ Bureau of Energy Efficiency

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Paper EA1 – Energy Auditor – Set A Solutions
8. The quantity of heat required to raise the temperature of a substance by 1 C is known as a) sensible heat 9. b) specific heat c) heat capacity d) latent heat
o

A three phase induction motor is drawing 12 Ampere at 440 Volts. If the operating power factor of the motor is 0.85 and the motor efficiency is 96%, then the mechanical shaft power output of the motor is a) 7.46 kW b) 7.77 kW c) 5.3 kW d) 23.4 kW

10.

The term missing in the following equation: Active Power = 1.732 x V x I x ? a) sin phi b) cos phi c) efficiency d) a constant

11.

Electrical resistance is defined as a) Current/Voltage b) Voltage x Current c) Ohm x Voltage d) Voltage/Current

12.

Energy management involves… a) combination of technical and managerial skills c) technical skills b) managerial skills d) energy audit skills

13.

Water flow in pipes is measured by a) pitot tube b) x-rays c) doppler effect d) electric fields

14.

The benchmark for energy performance parameter for air conditioning equipment is a) kW/kg of refrigerant handled 3 c) kcal/m of chilled water b) kW/ton of refrigeration d) kWh/ton of refrigeration

15.

One kWh of electricity is equivalent to how many heat units in Btu ? a) 860 b) 3412 c) 746 d) 12000

16.

Matching energy usage to requirement means providing a) just theoretical energy needed c) energy with minimum losses b) just the design needs d) less than what is needed

17.

In a chemical process two reactants A (200 kg) and B (200 kg) are used. If conversion is 50% and A and B react in equal proportions, the mass of the product formed is a) 300 kg b) 150 kg c) 400 kg d) 200 kg

18.

Diagrammatic representation of input and output energy streams of an equipment or system is know as a) mollier diagram d) balance diagram b) sankey diagram c) psychrometric chart

19.

Coal with 30% ash is fired in a boiler. Coal consumption is 50 tonnes on a specific day. Clinker is formed by 1% of the ash sticking to boiler tubes. How many tonnes of ash are going out of the boiler on this day. a) 14.85 b) 15 c) 15.15 d) 13.5

20.

An oil fired boiler operates at an excess air of 15%. If the stochiometric air to fuel ratio is 14 and oil consumption is 1000 kg per hour and 50% of the flue gas is diverted to a dryer, then the mass of flue gas leaving the boiler chimney in kg/ hour would be a) 3,990 b) 14,010 c) 8,050 (8,550) d) 7,650

_________________________ Bureau of Energy Efficiency

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Paper EA1 – Energy Auditor – Set A Solutions
21. In a force field analysis one of the indicators below is not considered a positive force a) high price of energy c) salary of staff 22. b) energy efficient technology available d) lack of awareness

Which of the following is least important of a good energy information system a) data accuracy b) data relevance c) data volume d) data validation

23.

The first vital step in an energy management programme is a) top management commitment d) energy audit b) measurements c) setting goals

24.

A public expression of an organization’s commitment on energy conservation is a) energy balance b) energy policy c) energy audit d) energy savings

25.

What is not the duty of an energy manager a) conduct an energy audit b) prepare an annual activity plan c) report to BEE and state level designated agency once a year d) prepare a scheme for efficient use of energy

26.

The factor that reflects best on the risk of the project while evaluating the present value of the expected future cash flow is a) life of project rate b) fuel cost inflation c) loan interest rate d) discount

27.

A sensitivity analysis is an assessment of a) cash flows b) risks due to assumptions d) best financing source c) capital investment

28.

The Return of Investment, ROI, is expressed as a) (first cost/first year benefits) x100 c) annual costs/capital cost b) NPV/ IRR d) (annual net cash flow/capital cost) x100

29.

The Net Present Value of a project at a discount rate of 16% with an investment of Rs 50,000 at the beginning of the first year, and savings of Rs 23,000 and Rs 36,000 at the end of the first and second year, respectively is a) 6,581 b) -246 c) 862 d) 3,419 (-3419)

30.

A sum of Rs 10,000 is deposited in a bank at the beginning of a year. The bank pays 6% interest annually. How much money is in the bank account at the end of the fifth year, if no money is withdrawn? a) 13,382 b) 12,625 c) 13,000 d) 10,937

31.

A contract in which the costs are paid from all or part of the energy cost savings is called a) performance contract b) traditional contract c) extended technical guarantee contract d) guaranteed savings performance contract

32.

A path is characterized by 4 parameters such as ES = earliest start time, EF= earliest finish time, LF = latest finish time, LS = latest start time. A path is critical if a) ES=EF or EF=LF c) ES=LS or EF=LF b) ES=LS and EF=LF d) LF=EF and EF=LS

_________________________ Bureau of Energy Efficiency

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Paper EA1 – Energy Auditor – Set A Solutions
33. The annual electricity bill for a plant is Rs 10 lakhs and accounts for 38% of the total energy bill. Furthermore the total energy bill increases by 5% each year. How high is the plant’s annual energy bill at the end of the third year? a) Rs 30.46 lakhs 34. b) Rs 26.32 lakhs c) Rs 38.42 lakhs d) none of the above

In Project Management the critical path in the network is a) the quickest path b) the shortest path d) the path where no activities have slack c) the path from start to finish

35.

CPM in project management refers to a) critical periodic management b) critical project monitoring c) critical path method d) cost project management

36.

The major difference between CPM and PERT is a) CPM provides graphic and PERT does not b) CPM uses fixed time estimates while PERT uses several time estimates c) CPM is an expansion of PERT d) PERT is an expansion of CPM

37.

The calorific value of coal is 4000 kCal/ kg. Find out the oil equivalent of 100 kg of coal if the calorific value of oil is 41,870 kJ/ kg a) 40 kg b) 56 kg c) 52 kg d) None of the above

38.

Fixed energy consumption can be determined from a a) bar chart b) vertical line chart c) pie chart d) X Y coordinate system

39.

Energy consumed for the period is given as 110 kWh for 10 tons and 200 kWh for 20 tons of production. The fixed energy consumption in kWh is… (No graph is needed to arrive at correct answer). a) 10 b) 40 c) 20 d) None of the above

40.

Large scattering on production versus energy consumption trend line indicates a) poor process control c) poor process monitoring b) many forced outages d) none of the above

41.

The ratio of energy consumption to corresponding production is called a) energy intensity c) production energy ratio b) specific energy consumption d) specific production ratio

42.

In a cumulative sum chart, if the graph is horizontal, then a) nothing can be said b) energy consumption is reduced c) specific energy consumption is increasing d) actual and calculated energy consumption are the same

43.

A firm substitutes (replaces) expensive oil and starts firing wood in a boiler. The following scenario is most likely a) higher fuel cost c) higher energy consumption b) better boiler efficiency d) less smoke in the stack

44.

Assume project A has an IRR of 85% and NPV of Rs 15,000 and project B has an IRR of 25% and NPV of 200,000. Which project would you implement first if financing is available and project technical life is the same? a) B b) A c) cannot be decided d) question does not make sense

_________________________ Bureau of Energy Efficiency

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Paper EA1 – Energy Auditor – Set A Solutions
45. Which of the following is not a part of energy consumption monitoring a) data recording c) data reporting 46. b) data analysis d) energy costing

The commitment period for emission reductions of industrialized countries as per Kyoto protocol is a) since 2001 b) 2008 – 2012 c) there is none d) 2012 -2022

47.

Global warming is mostly caused by emission of a) sulfur dioxide b) carbon monoxide c) carbon dioxide d) methane

48.

Under the Kyoto Protocol India has to cut emissions by a) 0% b) + 8% c) -8% d) 12%

49.

The process under the Kyoto Protocol by which industrialized countries may invest into or buy certified emission reductions is called. a) cleaner development mechanism c) prototype carbon trading b) clean development mechanism d) none of the above

50.

The ozone depletion process is due to a) Carbon Dioxide c) Nitrogen b) UV light breaking the ozone d) chlorine atoms destroying ozone molecules

_________________________ Bureau of Energy Efficiency

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Paper EA1 – Energy Auditor – Set A Solutions
Solution Key for Objective Type
Question 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Auditor A b d b c d b a c a b d a c b b c d b a 1 ALL d c a b a Question 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 Auditor A b, d b d ALL a d b a d c b a d c a b d c a d b c a b d

-------- End of Section - I ---------

ALL = One mark was awarded to all the examinees who have marked an answer for Question 20 & 29 and for Q26 one mark was awarded to examines who marked answer either b or d

_________________________ Bureau of Energy Efficiency

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Paper EA1 – Energy Auditor – Set A Solutions
Section - II: SHORT DESCRIPTIVE QUESTIONS

Marks: 10 x 5 = 50

(i) Answer all Ten questions (ii) Each question carries Five marks S-1 Classify the types of energy available on earth. a) primary and secondary energy b) commercial and non commercial c) renewable and non-renewable S-2 a) b) c) d) e) f) g) S-3 List five forms of energy with examples. chemical energy (coal and oil) nuclear energy (uranium atom) stored mechanical energy( rubber band, compressed springs) gravitational energy (water reservoir) kinetic energy ( all moving objects). radiant energy (solar energy, radio waves) electrical energy (movement of electrons) A 10 kW rated motor has a full load efficiency of 85%. Actual input measurement at a particular loading shows 415 Volt, 10 Amps, and PF of 0.68. Find out the motor loading in percentage. Solution Active power consumption at a particular loading = = = √3 kV x I x cos  √3 x 0.415 x 10 x 0.68 4.89 kW

10 kW means rated output power of the motor. When evaluating the load this has to be corrected to input condition by dividing this by efficiency. Full rated input power = 10 /0.85 = 11.76 kW Hence the motor loading = 4.89/11.76 = 41.58 %

S-4

Explain the difference between specific heat and heat capacity.

(i) Specific heat of a substance is the energy supplied to raise the temperature of 1 kg of the substance by 1 C, while (ii) The heat capacity of a substance is the energy required to raise the temperature of the entire mass of the substance by 1 C.

_________________________ Bureau of Energy Efficiency

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Paper EA1 – Energy Auditor – Set A Solutions
S-5 Give any five bench marking parameters followed for either equipment or industrial production. a) b) c) d) e) f) g) S-6 kWh/ton of refrigeration (air conditioner) % thermal efficiency (steam boiler) kWh/liter (oil fired furnace or diesel generator) kWh/ m3n( compressed air) kWh/ton of clinker (cement industry) kcal/kWh (gross heat rate in power plants) kWh/kg (yarn in textile industry) State definition of energy audit as defined in the Energy Conservation Act 2001.

Energy audit means the verification, monitoring and analysis of use of energy including submission of technical report containing recommendations for improving energy efficiency with cost benefit analysis and action plan to reduce energy consumption S-7 Calculate the net present value over a period of 3 years for a project with one investment of Rs 50,000 at the beginning of the first year and a second investment of Rs 30,000 at the beginning of the second year and fuel cost savings of Rs 40,000 each in the second and third year. The discount rate is 16%. 30,000 1.16 40,000 40,000 + 2 1.16 1.163

NPV

= =

- 50,000

-

+

- 50,000 – 25,862 + 29,727 + 25,626 = - Rs. 20,509

S-8

In a heat exchanger steam is used to heat 40 kg/ hour of furnace oil from 30o C to 90o C. The specific heat of furnace oil is 0.22 kcal/ kg o C. How much steam per hour is needed? Latent heat of steam is 540 kcal/ kg. = m cp t = 40 x 0.22 x (90-30) = 528 kcal/hour = 528 540 = 0.98 kg/hr

Heat required to raise temperature of furnace oil

Steam requirements S-9 Explain briefly PERT.

The Programme Evaluation and Review Technique (PERT) is a network model that allows for randomness in activity completion times. PERT uses three time estimates, optimistic, most likely and pessimistic. This helps in establishing the probability of completing a project within a specified time and take calculated risks before commencing a project. PERT has the potential to reduce both the time and cost required to complete a project.

_________________________ Bureau of Energy Efficiency

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Paper EA1 – Energy Auditor – Set A Solutions
S-10 List at least 5 steps involved in CUSUM analysis.

a) Plot the energy versus production graph for several months b) Draw the best fit straight line c) Derive the equation for the line d) Calculate the expected energy consumption based on the equation e) Calculate the difference between calculated and actual energy consumption f) Compute CUSUM g) Plot the CUSUM graph h) Estimate the savings accumulated

-------- End of Section - II---------

Section - III: LONG DESCRIPTIVE QUESTIONS
(i) Answer all Five questions (ii) Each question carries Ten marks

Marks: 5 x 10 = 50

L-1

Explain the difference between energy conservation and energy efficiency, and state one example where energy costs are reduced but energy consumption goes up.

Energy conservation and energy efficiency are separate but related concepts. Energy conservation is achieved when growth of energy consumption is reduced, measured in physical terms such as barrels of oil or tons of coal, etc. Energy conservation can therefore be the result of several developments such as annual production goes down, or technological progress such as modernization. Energy efficiency is achieved when energy intensity or specific energy consumption is reduced in a process, area or production line without affecting output or comfort level. Energy efficiency will therefore contribute to energy conservation. Example: Fuel switching from a high cost, gaseous or liquid fuel, to a low cost solid fuel in a boiler will usually reduce energy cost per unit (=specific energy consumption) but as well increase energy consumption due to reduced energy efficiency of the process.
In general any example of fuel switching to a cheaper fuel in Rs/kcal where combustion of the new fuel is less efficient will increase energy consumption but save energy costs.

_________________________ Bureau of Energy Efficiency

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Paper EA1 – Energy Auditor – Set A Solutions
L-2 A plant is using 4 tonnes/day of coal to generate steam. The calorific value of the coal is 4000 kcal/ kg. The cost of coal is Rs. 2,000/tonne. The plant substitutes coal with rice husks, as a boiler fuel, which has a calorific value of 3000 kcal/ kg and cost Rs. 700/tonne. Calculate the annual cost savings at 300 days of operation, assuming that the boiler efficiency decreases from 78% on coal to 72% on rice husks.

Coal energy used to generate to steam per day: 4,000 kg/day X 4,000 kcal/kg x 0.78 = 12,480,000 kcal/day To generate same amount of steam with rice husks 12,480,000 = “kg/day” X 3,000 kcal X 0.72, and solve for kg/day = 5.777 tonnes/day Annual savings are 4 x 300 x 2,000 – 5.77778 x 300 x 700 = Rs 1,186,667
Short cut is 4 x 300 x 2,000 - 4 x (4,000/3,000) x (0.78/0.72) x 300 x 700 = Rs 1,186,667

L-3

In a pumping system the motor operating efficiency is 90% and pump operating efficiency is 80%. The pump discharge flow is throttled causing 20% loss; moreover 28% are lost through friction in pipe fittings. The three phase motor operates at a power factor of 0.85, 440 Volt and 17 Ampere. (I) Calculate the water power available at the end of the piping system. (II) Calculate the overall system efficiency.

i) Power drawn by electric motor = 1.732 x 0.440 kV x 17 x 0.85 = 11.0 kW Power available on water is then 11.0 x 0.90 x 0.80 x (1- 0.2) x (1- 0.28) = 4.56 kW ii) System efficiency = 0.90 x 0.8 x (1 – 0.2) x (1 – 0.28) = (0.9 x 0.8 x 0.8 x 0.72) x 100 = 41.47% L-4 An investment of Rs 1 Lakh is made for a variable speed drive at the beginning of the year, which is also the date of first operation. Savings expected over 4 years are Rs. 10,000, Rs. 20,000, Rs. 30,000 and Rs. 35,000 respectively. Find out the Net Present Value at the end of the 4th year, if the discount rate is 18%. Would you invest in this measure? Explain your decision.

NPV

=

= -1,00,000 +

10,000 + 1.18

20,000 (1.18)2

+

30,000 (1.18)3

+

35,000 (1.18)4

= - 100,00 + 8,475 + 14,364 + 18,259 + 18,053 = - Rs 40,849 One should not invest in this measure; NPV is highly negative even after 4 years.

_________________________ Bureau of Energy Efficiency

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Paper EA1 – Energy Auditor – Set A Solutions
L-5 Use CUMSUM technique to develop a table and to calculate energy savings for a 6 months period. For calculating total energy saving, average production can be taken as 4000 MT per month. Refer to field data given in table below. Month Actual kWh/MT Jan Feb Mar Apr May Jun 252 238 287 287 359 276 265 265 300 265 310 265 SEC, Predicted SEC, kWh/MT

Month

Actual SEC Predicted SEC kWh/MT kWh/MT 265 265 300 265 310 265

Diff (+ = sav) 13 27 13 -22 -49 -11

CUMSUM (- = sav) -13 -40 -53 -31 18 29

Jan Feb Mar Apr May Jun

252 238 287 287 359 276

Negative savings i.e additional energy consumption over a period of six months are 29 x 4000 = 116,00 kWh

……. End of Section - III ---------

_________________________ Bureau of Energy Efficiency

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