A heat pump operates on the ideal vapor-compression refrigeration cycle and uses refrigerant-22 as the working fluid. The operating conditions for this heat pump are evaporator saturation temperature of −5°C and the condenser saturation temperature of 45°C. Selected data for refrigerant-22 are provided in the following table.
For R-22 at P = 1728 kPa and s = 0.9344 kJ/kg·K, T = 68.15°C and h = 283.7 kJ/kg. Also, take cp,air = 1.005 kJ/kg·K.
(a) Sketch the hardware and the T-s diagram for this heat pump application. (b) Determine the COP for this unit. (c) The condenser of this unit is located inside the air handler of an office. If the air flowing through the air handler is limited to a 20°C temperature rise, determine the ratio of volume flow rate of air to mass flow rate of R-22 through the air handler, in (m3 air/min)/(kg R-22/s).
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Thermodynamics: An Engineering Approach
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