Chapter 5, Problem 5.28P

A power cycle operates between hot and cold reservoirs at 900 K and 300 K, respectively. At steady state the cycle develops a power output of 0.38 MW while receiving energy by heat transfer from the hot reservoir at the rate of 1 MW.Determine the thermal efficiency and the rate at which energy is rejected by heat transfer to the cold reservoir, in MW for the following.(a) The power cycle and conditions above. Determine the thermal efficiency and the rate at which energy is rejected by heat transfer to the cold reservoir, in MW.(b) A reversible power cycle operating between the reservoirs and receiving the same rate of heat transfer from the hot reservoir as in part (a). Determine the thermal efficiency and the rate at which energy is rejected by heat transfer to the cold reservoir, in MW.

At steady state, a refrigeration cycle operates between hot and cold reservoirs at 300K and 275K respectively. The refrigerator removes 600 kW of heat from the cold reservoir. If the cycle's coefficient of performance is 4, determine the power input required in kW. Compare this with the minimum theoretical power required in kW.

A reversible heat pump cycle operates at steady state between hot and cold reservoirs at TH = 30°C and Tc 10°C, respectively. The rate of heat transfer at the high temperature is 10 kW. a. Determine the net power input, in kW. b. Determine the heat transfer rate from the cold reservoir at Tc, in kW. c. Determine the coefficient of performance of the cycle.