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QUESTION 3 [25 MARKS] a) Refrigerant-134a enters the condenser of a residential heat pump at 700 kPa and 45°C at a rate of 0.03 kg/s and leaves at 700 kPa with 30 percent quality. The compressor consumes 1.5 kW of power. Calculate the coefficient of performance (COP) of the heat pump. Please state your assumption. (13 Marks) b) An inventor claims to have developed a cyclical engine for use in space vehicles that operates with a nuclear-fuel-generated energy source at temperature of 600 K and a sink at 300 K. He also claims that this engine produces 3.5 kW. The heat supplied to the engine is 30, 000 kJ/h. Determine whether this claim is valid or not and explain your reason? (6 Marks) c) A refrigerator operating on the reversed Carnot cycle has a measured work input of 300 kW and heat rejection of 2800 kW to a heat reservoir. The temperature of the heat source is -4°C. i) Calculate the cooling load supplied to the refrigerator (kW). (2 Marks) ii) Determine the temperature of the heat reservoir (°C). (4 Marks)

          QUESTION 3 [25 MARKS]

a) Refrigerant-134a enters the condenser of a residential heat pump at 700 kPa and 45°C at a rate of 0.03 kg/s and leaves at 700 kPa with 30 percent quality. The compressor consumes 1.5 kW of power. Calculate the coefficient of performance (COP) of the heat pump. Please state your assumption.
(13 Marks)

b) An inventor claims to have developed a cyclical engine for use in space vehicles that operates with a nuclear-fuel-generated energy source at temperature of 600 K and a sink at 300 K. He also claims that this engine produces 3.5 kW. The heat supplied to the engine is 30, 000 kJ/h. Determine whether this claim is valid or not and explain your reason?
(6 Marks)

c) A refrigerator operating on the reversed Carnot cycle has a measured work input of 300 kW and heat rejection of 2800 kW to a heat reservoir. The temperature of the heat source is -4°C.
i) Calculate the cooling load supplied to the refrigerator (kW).
(2 Marks)
ii) Determine the temperature of the heat reservoir (°C).
(4 Marks)

QUESTION 3 [25 MARKS]

a) Refrigerant-134a enters the condenser of a residential heat pump at 700 kPa and 45°C at a rate of 0.03 kg/s and leaves at 700 kPa with 30 percent quality. The compressor consumes 1.5 kW of power. Calculate the coefficient of performance (COP) of the heat pump. Please state your assumption.
(13 Marks)

b) An inventor claims to have developed a cyclical engine for use in space vehicles that operates with a nuclear-fuel-generated energy source at temperature of 600 K and a sink at 300 K. He also claims that this engine produces 3.5 kW. The heat supplied to the engine is 30, 000 kJ/h. Determine whether this claim is valid or not and explain your reason?
(6 Marks)

c) A refrigerator operating on the reversed Carnot cycle has a measured work input of 300 kW and heat rejection of 2800 kW to a heat reservoir. The temperature of the heat source is -4°C.
i) Calculate the cooling load supplied to the refrigerator (kW).
(2 Marks)
ii) Determine the temperature of the heat reservoir (°C).
(4 Marks)

Added by Gooi E.

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