1. An air conditioning plant using refrigerant R 134a has evaporating and condensing temperatures of 0°C...
oblem 1: An air conditioner based on the theoretical single-stage cycle is using Refrigerant- 134a as the refrigerant operates with a condensing temperature of 100°F and evaporating temperature of 0°F. The air conditioner produces 5 tons of refrigeration. Determine: (a) The coefficient of performance of the cycle and the rate of refrigerant flow. (b) The condenser of the air conditioner is designed to reject the heat from the refrigerant. Air (Cp 0.24 Btu/lb. °F, p 0.077 lb/ft3) flows across the...
A refrigerant 12 refrigeration system operates at 45oC and -15oC condensing and evaporating temperature respectively. If the system used to produced 10 metric tons of Ice at -12oC from raw water at 28oC in 24 hours. Heat losses is 25% of product load. The compressor where is twice the bore has a volumetric efficiency of 90% at 1250 rpm. Determine the following: (a) the Tons of Refrigeration in KW (b) the Coefficient of Performance (c) the dimension of the Compressor...
A commercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at by The refrigerant enters the condenser at compressor consumes 3.3 kW of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration load, (e) the COP, and (d) the g waste heat to cooling water that enters the condenser at 18°C at a rate of 0.25 kg/s and leaves at 26°C. 1.2 MPa and 50°C and leaves at the same...
1) A commercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at -30°C by rejecting its waste heat to cooling water that enters the condenser at 16 °C at a rate of 0.25 kg/s and leaves at 26°C. The refrigerant enters the condenser at 1.2 MPa and 65°C and leaves at 42°C. The inlet state of the compressor is 60 kPa and -34°C and the compressor is estimated to gain a net heat of...
A vapor compression cycle using R134a as the refrigerant operates with evaporating and condensing temperatures of -5°C and 40°C. Calculate (i) Carnot cycle compression work, (ii) excess work due to the ‘superheat horn’, (iii) the loss of work due to throttling, and (iv) the loss in refrigeration capacity due to throttling.
A commercial refrigerator with refrigerant-134a as the working fluid is used to keep the refrigerated space at −25°C by rejecting waste heat to cooling water that enters the condenser at 20°C at a rate of 0.25 kg/s and leaves at 26°C. The refrigerant enters the condenser at 1.2 MPa and 50°C and leaves at the same pressure subcooled by 5°C. If the compressor consumes 3.3 kW of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration...
Problem 4.040 SI Refrigerant 134a enters an air conditioner compressor at 4 bar, 20°C, and is compressed at steady state to 12 bar, 80°C. The volumetric flow rate of the refrigerant entering is 8.5 m3/min. The work input to the compressor is 127.5 kJ per kg of refrigerant flowing Neglecting kinetic and potential energy effects, determine the magnitude of the heat transfer rate from the compressor, in kw kW the tolerance is +/-596 Click if you would like to Show...
1. A refrigerator uses refrigerant-134a as the working fluid and operates between -5 oC and 40 oC. The compressor, which is a reciprocating type, rotates at 1500 rpm. The compressor has 4 cylinders. The cylinder diameter is 120 mm and the stroke is 100 mm. The clearance volume is 5%. Find: Clearance volumetric efficiency, the mass flow rate of the refrigerant the power input to the compressor, the refrigeration capacity the COP of the system For above compressor type, sketch...
A freezer is designed, based on vapor-compression refrigeration cycle. The designed conditions are: R-134a as refrigerant, with a cooling capacity of 500 kW; compressor of 70% efficiency, with a superheat of 10°C before compressor inlet; operation temperature of -10°C inside the refrigerator, with the environment temperature of 25°C outside the refrigerator; Determine the pressure range of refrigeration cycle if a 10°C difference is required to ensure effective heat transfer of evaporator and condenser; Plot the refrigeration cycle on P-h diagram;...
A Refrigeration System Using R-134A In a refrigeration system, the refrigerant R-134A begins as saturated vapor at -15°(State 1). It then goes through a reversible adiabatic compressor to reach State 2. After flowing through the condenser (a heat exchanger), the refrigerant exits as saturated liquid at 70°C (State 3). It is then throttled by going through an expansion valve, to reach State 4. It finishes the cycle by going through another heat exchanger (the evaporator), to return to State 1....