A geothermal heat pump is used to provide a house with 5 kW of heating. The house is at 25°C and the ground temperature is 10°C. Whenever there is heat transfer, assume a minimum temperature difference of 20°C between the refrigerant and the house or between the refrigerant and the ground. You can assume sat vapor leaving the evaporator and sat liquid leaving the condenser for optimum performance. Assume a compressor efficiency of 100% (except for part 6).
For the cycle above,
1) Find the heat transfer and work for each component
2) Find the entropy production for each component. Rank the components form most entropy production to least.
3) Find the COP
4) Find the best possible COP for a heat pump operating between the house and the ground
5) Using (To*sigma) as an approximation, about how much could the electricity usage be reduced by adding a device that recovers energy during a pressure drop (replacing the expansion valve)?
6) Vary the compressor efficiency from 50% to 100% by removing the vale for compressor efficiency from your main code, creating a parametric table, and entering values from 50% to 100% efficiency in the table. Include compressor efficiency, COP, Win, and sigma_dot_compressor in your parametric table.