refrigiration_and_air_conditioning by jJ9JI5Z

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									            Technical Seminar
                   on
Refrigeration & Air Conditioning


 Prepared By :
         INTRODUCTION
• The electrical energy is utilized by
  converting it into one form or other for
  getting suitable output from it.
• The utilization electrical energy for the
  refrigeration and air conditioning is fast
  replacing the old methods.
WHAT IS REFRIGERATION &
  AIR CONDITIONING ?
• The process of reducing the temperature of a body
  from the general level of temperature of
  surroundings is called refrigeration.
• Air-conditioning        means        control   of
  temperature,humidity,purity and movement of air.
• The working conditions and comfort for human
  beings is improved by air-conditioning.
• The temperature is brought down during summer
  and increased during winter without causing any
  discount.
         REFRIGERATOR

• This is the machine by which the
  temperature of substances is lowered by
  storing them in this machine.
                 PRINCIPLE
• A refrigerator works on
  the principle of cooling
  caused by evaporation.
• when we dip our finger
  in petrol or spirit,and
  the finger is taken out
  cooling is felt. This is
  because when petrol or
  spirit evaporates it
  draws heat from the
  finger thus cooling it.
           REFRIGERANT

• The refrigerant is generally a gas which
  circulated through different stages to extract
  the heat from the substances.
• The various refrigerants used are carbon
  dioxide(CO2),sulphur
  dioxide(SO2),ammonia(NH3),Freon(F-12)
  and methyl chloride etc.
  VAPOUR COMPRESSION CYCLE
• The main purpose of vapour
  compression cycle is to
  remove heat from the
  refrigerant by putting it into a
  stage for reuse.
• The various stages are
      1.compression
       2.condension
      3.expansion
      4.evaporation
             APPLICATION
• The vapour compression refrigeration cycle is
  employed for the following purposes
  –   Domestic refrigerator,
  –   Water cooler,
  –   Air conditioner,
  –   Ice plant,
  –   cold storage etc.
 DOMESTIC REFRIGERATOR
• The actual lay out of domestic refrigerator
  is shown in figure below.
 ELECTRICAL CIRCUIT OF
    REFRIGERATOR
• The main parts of the electrical
  circuit are shown in figure
  below
• The various parts are
  1. motor compressor unit
  2. starting relay
  3. thermostat
  4. overload protector
  5. cabinet light
  6. drier assembly.
 MOTOR COMPERESSOR UNIT
• The motor is a single phase capacitor start
  motor.
• The actual capacity of the motor depends
  upon the size of the refrigerator.
• But generally the horsepower of motors
  varies from 7/32 H.P. to 1/8 H.P.
• Mostly the motor and compressor are in one
  unit and is known a sealed unit.
         STARTING RELAY
• The motor is operated
  by this relay which is
  also called motor
  protective relay.
• It essentially consists
  of a plunger on which
  a coil is wound .
• The figure below
  shows              the
  arrangement:
                THRMOSTAT
• A thermostatic
  switch is used on all
  the household
  refrigerators by
  which the
  temperature is
  controlled, and it is
  called thermostat.
• The construction of a
  thermostat used in a
  refrigerator is shown
  in figure below:
   OVERLOAD PROTECTOR
• This is a thermal device which opens the
  circuit of the motor when overloaded and
  is called overload protector.
• The figure below shows the enlarged view
  of a overload protector.
         CABINET LIGHT

• This circuit contains a lamp and a switch.
• The switch is called door switch and so
  installed that when the door is closed,the
  bulb remains off.
• When the door is opened, the bulb remains
  on.
        DRIER ASSEMBLY

• This assembly is not employed on all the
  domestic refrigerators.
• This is a high resistance wire passing
  around the drier to remove the moisture
  from the refrigerator.
• This is connected across the supply by the
  thermostat.
        AIR-CONDITIONER
• The room air conditioner is used to condition the
  air of a particular space occupied by the human
  beings i.e. office, room etc.
• It has automatic operation to control and maintain
  the humidity of air.
• There are two parts divided by a partition with a
  small opening at the top as
      1.outdoor part
      2.indoor part
          AIR-CONDITIONER
• The complete operation of
  an air conditioner can be
  studied under these sub
  headings-
  1.vapour compression cycle
  2.air circulation
  3.electrical circuit
• The figure below shows a
  room air conditioner
             CONCLUSION
• The electrical energy is utilised by converting it into
  one form or the other form for getting suitable
  output from it.
• The utilization of electrical energy for the
  refrigeration and air conditioning is fast replacing
  the old methods.
• Refrigeration and Air Conditioning has become a
  necessity in every sphere of human utility and
  industrial set-ups.
Thank You…

								
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