Refrigeration and air conditioning RAC

Useful in learning basic of refrigeration and air conditioning.

1. Refrigeration and air conditioning Presented by : PUNGAL A.M.

2. What is Refrigeration : It is defined as the science of providing and maintaining temperature below that of surrounding atmosphere. It means that continuously extraction of heat from a body whose temperature is already below the temperature of its surrounding.

3. Refrigeration effect :- It is defined as the rate of removal of heat from a substance which is to be cooled. Coefficient of performance. (COP) :- C.O.P is a measure of efficiency of a refrigeration system and is defined as C.O.P= Refrigeration effect upon input energy

4. Heat pump: It is a device which transfer heat from low temperature to high temperature by supplying some external work. To avoid confusion the efficiency of heat pump is replaced by coefficient of performance ( C.O.P) If the purpose of heat pump is to take out the heat from low temperature source T1 and supply it to a room temperature T2 for heating then

5. Difference between heat pump and Refrigerator :

6. Types of Refrigeration System : Simple Vapour compression cycle Vapour Absorption Cycle

7. Simple Vapour Compression. System:

8. Components of Vapour Compression system : Compressor Condenser Receiver Expansion Valve Evaporator

9. Types of Vapour Compression Cycles: Dry Vapour Compression Cycles Wet Vapour Compression Cycles. i) Wet Compression discharge Dry saturated ii) Wet Compression discharge Wet saturated Super Heating of Vapour Compression Cycles Subcooling of Vapour Compression Cycles VCC Of Super Heating and Subcooling

10. Application of simple Vapour compression refrigeration system It is used in Ice plant It is used in Domestic Refrigerators​

11. Ice plant:

12. Domestic Refrigerator :

13. Simple Vapour Absorption System (VAS) :

14. Practical Vapour Absorption System:

15. Advantages of Vapour Absorption refrigeration system over VCC refrigeration system: No moving parts, no noise , less wear pump motor is small compared to VCC Initial cost is less compared to VCC Elimination of having electrical load simple in operation Automatic Starting and stopping

16. Difference between VAS and VCC:

17. Psychometric terms : Dry Air :- The mixture of Nitrogen the oxygen niglecting water vapour is known as Dry Air Wet Air :- It is the mixture of Dry Air and Water Vapour is known as Wet Air Saturated Air :- It is the mixture of Dry Air and Water Vapour and it is said saturated when it diffused maximum amount of water vapour depends on absolute pressure and temperature

18. Dry Bulb Temperature :- It is the temperature recorded by ordinary thermometer with a clean , dry sensing element when bulb of thermometer is expose to air Wet Bulb Temperature:- it is the temperature recorded by ordinary thermometer when it's bulb is covered by a wet cloth exposed to the air . Dew Point Temperature :- It is the temperature of air recorded by ordinary thermometer when the mixture present in air start to condensed

19. Specific Humidity :- The mass of water vapour present in 1 kg of moist air it known as Specific Humidity Absolute Humidity :- It is defined as the mass of water vapour in unit volume of moist air is called as Absolute Humidity Relative Humidity :- It is defined as the ratio of actual mass of water vapour in unit volume of moist air to the mass of water vapour in the same volume of saturated Air at the same temperature and pressure

20. Dalton's low of partial pressure :- The total pressure exerted by the mixture of air and Water Vapour is equal to the sum of the pressures , which each constituent would exert , if the occupied the same space by itself Pb = Pa + Pv where , Pb = total pressure exerted by an air vapour mixture Pa = partial pressure of air Pv = partial pressure of water vapour

21. Psychometric chart :-

22. Description of Psychometric process :- Sensible cooling sensible Heating Cooling with Dehumidification Heating with Dehumidification​

23. Air conditioning system :- Air conditioning may be defined as simultaneous control of temperature , Humidity , motion of air and purity of air within the enclosed space

24. Window Air Conditioning:-

25. Thank you