1. R-134 enters the condenser of a window air conditioning unit at 800 kPa and 35 C and leaves as a saturated liquid at the same pressure. The compressor current draw is measured to be 5 amps at 240 V and the R-134 has a mass flow rate of 0.018 kg/s. If needed, refer to Figure 6-19 for a schematic of a refrigeration system.
What is the COP of the AC unit?
What is the rate of heat rejection to the outside air via the condenser?
2. Three heat engines operate between a source at 600 C and a sink at 25 C. Heat engines A & B are completely reversible while heat engine C is NOT.
a) Heat engine A rejects 500 kJ. What is the net work output of Engine A?
b) Heat Engine B produces half the amount of work as engine A. What is the heat input QH for engine B?
c) Heat Engine C is purported to produce 350 kJ of net work while rejecting 200 kJ of Heat. Is this possible? Why or why not?