Chapter 8, Problem 8.26CU

Components of a heat pump for supplying heated air to a dwelling are shown in the schematic below. At steady state, Refrigerant 134a enters the compressor at 6 °C, 3.2 bar and is compressed adiabatically to 75 °C, 14 bar. From the compressor, the refrigerant passes through the condenser, where it condenses to liquid at 28 °C, 14 bar. The refrigerant then expands through a throttling valve to 3.2 bar. The states of the refrigerant are shown on the accompanying T-s diagram. Return air from the dwelling enters the condenser at 20 °C, 1 bar with a volumetric flow rate of 0.42 m³/s and exits at 50 °C with a negligible change in pressure. Using the ideal gas model for the air and neglecting kinetic and potential energy effects, (a) determine the rates of entropy production, in kW/K, for control volumes enclosing the condenser, compressor, and expansion valve, respectively. (b) Discuss the sources of irreversibility in the components considered in part (a). Indoor return air T5 = 20°C P₁ = 1…

A heat engine has to exchange heat with -----thermal reservoir at --- different temperatures to produce work in a complete cycle. Select one: O a. one, two O b. two, two O c. two, one O d. one, one

True Or False