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Problem 15. A heat pump is used to maintain a warm area at 30 degC by...
6. An office building requires a heat transfer rate of 20 kW to maintain the inside temperature a...
6. An office building requires a heat transfer rate of 20 kW to maintain the inside temperature at 21°C when the outside temperature is 0°C. A vapor-compression heat pump with Refrigerant 134a as the working fluid is to be used to provide the necessary heating. The compressor operates adiabatically with an isentropic efficiency of 82%. Specify appropriate evaporator and condenser pressures of a cycle for this purpose assuming Δ1cond-Al evap-10°C, as shown below. The states are numbered as shown below....
A heat pump using refrigerant-134a as a refrigerant operates its condenser at 800 kPa and its...
A heat pump using refrigerant-134a as a refrigerant operates its condenser at 800 kPa and its evaporator at −1.25°C. It operates on the ideal vapor-compression refrigeration cycle. What is the COP of the heat pump for the case when the vapor entering the compressor is superheated by 2°C and for the case when the compressor has no irreversibilities? The COP of the heat pump when the compressor has no irreversibilities is____. The COP of the heat pump when the vapor...
QUESTION 3 A heat pump that operates on the ideal vapor compression cycle with refrigerant-134a is...
QUESTION 3 A heat pump that operates on the ideal vapor compression cycle with refrigerant-134a is used to heat water from 15°C to 45°C at a rate of 0.12 kg/s. the condenser and evaporator pressures are 1.4 and 0.32 MPa, respectively Determine: (a) The power input to the heat pump
QUESTION 3 A heat pump that operates on the ideal vapor compression cycle with refrigerant-134a is used to heat water from 15°C to 45°C at a rate of 0.12 kg/s....
Refrigerant 134a flows through an ideal vapor compression heat pump system with a heating capacity of...
Refrigerant 134a flows through an ideal vapor compression heat pump system with a heating capacity of 60,000 Btu/hr. The condenser operates at 200 psi, and the evaporator temperature is 0°F. The refrigerant is a saturated vapor at the evaporator exit and a saturated liquid at the condenser exit. The temperature at the compressor exit is 180°F. Assuming the compressor is not 100% isentropic, determine: a) Mass flow rate (lbm/min) b) Compressor power (hp) c) Isentropic compressor efficiency d) Coefficient of...
V6.23 Figure P6.23 shows a Carnot heat pump cycle operating at steady state with ammonia as...
V6.23 Figure P6.23 shows a Carnot heat pump cycle operating at steady state with ammonia as the working fluid. The condenser tem perature is 49°C, with saturated vapor entering and saturated liquid exiting. The evaporator temperature -12°C a. Determine the heat transfer and work for each process, in kJ/kg of ammonia flowing. o56, 73 kJ b. Evaluate the coefficient of performance for the heat pump. 5, c. Evaluate the coefficient of performance for a Carnot refrigeration cycle operating as shown...
2. (10 points) An ideal vapor-compression refrigeration cycle is modified to include a counter- flow heat...
2. (10 points) An ideal vapor-compression refrigeration cycle is modified to include a counter- flow heat exchanger, as shown below. Ammonia leaves the evaporator as saturated vapor at 1.0 bar and is heated at constant pressure to 5 "C before entering the compressor. Following isentropic compression to 18 bar, the refrigerant passes through the condenser, exiting at 40 C, 18 bar. The liquid then passes through the heat exchanger, entering the expansion valve at 18 bar. If the mass flow...
Condenser Compressor An ideal vapor-compression refrigeration cycle is modified to include a counter-flow heat exchanger as...
Condenser Compressor An ideal vapor-compression refrigeration cycle is modified to include a counter-flow heat exchanger as shown. Refrigerant 134a leaves the evaporator as saturated vapor at 0.10 MPa and is heated at constant pressure to 20°C before entering the compressor. Following isentropic compression to 1.4 MPa, the refrigerant passes through the condenser and exits at 45°C and 1.4 MPa. The liquid then passes through the heat exchanger and enters the expansion valve at 1.4 MPa. The mass flow rate of...
A vapor- compression heat pump uses ammonia to provide heat with a geothermal source of heat...
A vapor- compression heat pump uses ammonia to provide heat with a geothermal source of heat at 50oF. The heat pump condenser operates at 72oF while the evaporator is at 48oF. Assuming an ideal dry compression cycle and for a heating of 7 tons (refrigeration unit) determine the power required of the compressor and the flow rate of ammonia.
In a vapor-compression refrigeration cycle, ammonia exits the evaporator as saturated vapor at -22 °C. There...
In a vapor-compression refrigeration cycle, ammonia exits the
evaporator as saturated vapor at -22 °C. There are
irreversibilities in the compressor. The refrigerant enters the
condenser at 16 bar and 160 °C, and saturated liquid exits at 16
bar. There is no significant heat transfer between the compressor
and its surroundings, and the refrigerant passes through the
evaporator with a negligible change in pressure.
Calculate the coefficient of performance, b, and the isentropic
compressor efficiency, defined as:
2s Condenser Expansion...
A heat pump operates on the ideal vapor compression refrigeration cycle with R-134a. The condenser pressure...
A heat pump operates on the ideal vapor compression refrigeration cycle with R-134a. The condenser pressure is 1.2 MPa and the specific enthalpy at the inlet to condenser is 279 kJ/kg. If the mass flow rate of the refrigerant is 0.193 kg/s, the rate of heat supply to the heated space is answer is 31.1 kw
6. An office building requires a heat transfer rate of 20 kW to maintain the inside temperature at 21°C when the outside temperature is 0°C. A vapor-compression heat pump with Refrigerant 134a as the working fluid is to be used to provide the necessary heating. The compressor operates adiabatically with an isentropic efficiency of 82%. Specify appropriate evaporator and condenser pressures of a cycle for this purpose assuming Δ1cond-Al evap-10°C, as shown below. The states are numbered as shown below....
QUESTION 3 A heat pump that operates on the ideal vapor compression cycle with refrigerant-134a is used to heat water from 15°C to 45°C at a rate of 0.12 kg/s. the condenser and evaporator pressures are 1.4 and 0.32 MPa, respectively Determine: (a) The power input to the heat pump
QUESTION 3 A heat pump that operates on the ideal vapor compression cycle with refrigerant-134a is used to heat water from 15°C to 45°C at a rate of 0.12 kg/s....
Refrigerant 134a flows through an ideal vapor compression heat pump system with a heating capacity of 60,000 Btu/hr. The condenser operates at 200 psi, and the evaporator temperature is 0°F. The refrigerant is a saturated vapor at the evaporator exit and a saturated liquid at the condenser exit. The temperature at the compressor exit is 180°F. Assuming the compressor is not 100% isentropic, determine: a) Mass flow rate (lbm/min) b) Compressor power (hp) c) Isentropic compressor efficiency d) Coefficient of...
V6.23 Figure P6.23 shows a Carnot heat pump cycle operating at steady state with ammonia as the working fluid. The condenser tem perature is 49°C, with saturated vapor entering and saturated liquid exiting. The evaporator temperature -12°C a. Determine the heat transfer and work for each process, in kJ/kg of ammonia flowing. o56, 73 kJ b. Evaluate the coefficient of performance for the heat pump. 5, c. Evaluate the coefficient of performance for a Carnot refrigeration cycle operating as shown...
2. (10 points) An ideal vapor-compression refrigeration cycle is modified to include a counter- flow heat exchanger, as shown below. Ammonia leaves the evaporator as saturated vapor at 1.0 bar and is heated at constant pressure to 5 "C before entering the compressor. Following isentropic compression to 18 bar, the refrigerant passes through the condenser, exiting at 40 C, 18 bar. The liquid then passes through the heat exchanger, entering the expansion valve at 18 bar. If the mass flow...
Condenser Compressor An ideal vapor-compression refrigeration cycle is modified to include a counter-flow heat exchanger as shown. Refrigerant 134a leaves the evaporator as saturated vapor at 0.10 MPa and is heated at constant pressure to 20°C before entering the compressor. Following isentropic compression to 1.4 MPa, the refrigerant passes through the condenser and exits at 45°C and 1.4 MPa. The liquid then passes through the heat exchanger and enters the expansion valve at 1.4 MPa. The mass flow rate of...
In a vapor-compression refrigeration cycle, ammonia exits the
evaporator as saturated vapor at -22 °C. There are
irreversibilities in the compressor. The refrigerant enters the
condenser at 16 bar and 160 °C, and saturated liquid exits at 16
bar. There is no significant heat transfer between the compressor
and its surroundings, and the refrigerant passes through the
evaporator with a negligible change in pressure.
Calculate the coefficient of performance, b, and the isentropic
compressor efficiency, defined as:
2s Condenser Expansion...
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