A heat engine is used to drive a heat pump. The heat transfers from the heat engine and from heat pump are used to heat the water circulating through the radiators of the building. The efficiency of the heat engine is 27% and the COP of the pump is 4. - Mumbai university > MECH > SEM 3 > THERMO

Marks: 10M

Year: May 2015

Let Q1 be heat entering the engine and Q2 and Q3 be the heat transfer to water.

To find: (Q2+Q3)/Q1 = k

Given: η = 0.27; COP =4

Solution: W = ηQ1 = 0.27Q1

Q2 = (1-η) Q1 = 0.73 Q1

Q3 = COP x W = 4 x 0.27 x Q1 = 1.08 Q1

K = (0.73 Q1 + 1.08 Q1)/Q1 = 1.81