A vapour compression refrigerator using R134a works between temperature limits of -5 °C and 40 °C. The refrigerant leaves the compressor dry saturated.

Two methods used to power refrigeration compressors on a ship are _____and ____.

Refrigerators currently being manufactured in the United States are using______as their refrigerant.

The defrost cycle in a domestic refrigerator may be terminated by two methods: ___and___.

The operating condition for the single compressor in a household refrigerator is the lowest box temperature, which is typically A. 0F B. -20F C. 20F D. 40F

2. A refrigeration system with a capacity of 15 tons of refrigeration, operates at 150 kPa in the evaporator, while the condenser is 1450 kPa. If refrigerant R-717 is saturated, calculate the theoretical power required to operate the compressor. Compressor Power = Answer   kW.

Number 2 A refrigeration system with a capacity of 10 tons of refrigeration, operates at 210 kPa in the evaporator, while in the condenser it is 1100 kPa. If refrigerant R-717 is saturated, calculate the theoretical power required to operate the compressor. Compressor Power = Answer in kW.

Q2/ A refrigerator with tetrafluoroethane (R-134a) as refrigerant operate with an evaporation temperature of -34 °C and a condensation temperature of 18 °C. Saturated liquid refrigerant from the condenser flows through an expansion valve into the evaporator, from which it emerges as saturated vapor. What is the coefficient of performance (COP) of the refrigerator? (Note: The cycle is vapor compression cycle).

2. A refrigeration system with a capacity of 10 tons of refrigeration, operates at 210 kPa in the evaporator, while in the condenser it is 1170 kPa. If refrigerant R-717 is saturated, calculate the theoretical power required to operate the compressor. Compressor Power = AnswerkW

9. A 9.5 tonnes capacity of ammonia refrigerator operates between evaporator and condenser temperature of -13°C and 28°C is needed in a food storage locker. The refrigerant is sub-cooled by 4°C before entering the expansion valve. The vapour is 0.90 dry as it leaves the evaporator coil. The compression in the compressor is adiabatic type. Using p-h chart find (i) Condition of vapour at outlet of the compressor (ii) Condition of vapour at entrance to evaporator (iii) С.О.Р. (iv) Power required in kW Neglect valve throttling and clearance effect.