In refrigeration process, a region is cooled and the temperature was maintained at -15oC. The cooling water used in the refrigeration is 25oC. If the refrigerant is HFC-134a, and the heat transfer temperature difference is 10oC, Calculate COP (ω) and mass flowrate for a vapor-compression cycle if the rating of the refrigeration process is 100,000 kJ/h and the efficiency of the compression is 0.75.

A heat pump with refrigerant-134a (R-134a) as the working fluid is used to keep a space at 21 °C by absorbing heat from geothermal water that enters the evaporator at Ti,water = 60 °C at a rate of 0.067 kg/s and leaves at To,water = 40 °C. The specific heat of liquid water is 4.18 kJ/(kg∙K). Refrigerant enters the evaporator at TR-134a = 10 °C with a quality of x = 12 % and leaves at the same pressure as saturated R-134a vapor at the same temperature. The compressor consumes 1.4 kW of power. 1)Determine the mass flow rate (in kg/s) of the refrigerant. 2)Determine the rate of heat (in kW) supplied to the space.  2)Determine the COP of the heat pump.  4)Determine the ideal minimum power input (in kW) to the compressor for the same rate of heat supply

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ercise 6 6.1 A surface condenser is fitted with separate air and condensate outlets. A portion of the cooling surface is screened from the incoming steam and the air is passes over these screened tubes to the air extraction and becomes cooled below the condensate temperature. The condenser receives 20 000kg/hr of dry saturated steam at 36.2°C. At the condensate outlet the temperature is 34.6°C TK and at the air extraction the temperature is 29°C. The volume of air and vapour leaving the condenser is 3.8m3/min. Assume constant pressure throughout the condenser, calculate: 6.1.1 the mass of air removed per 10 000kg of steam (2.63kg); 6.1.2 the mass of steam condensed in the air cooler per minute (0.5kg/min)%3B 6.1.3 the heat rejected to the cooling water (13451kW).