Question

Que.2a With suitable diagrams, describe the geothermal resource types 6 marks) b Show that the efficiency of a heat pump is higher in the heating mode than in the cooling mode. (2 marks) Que.2c A heat pump is used to heat a house in the winter and cool it in the summer. The loads are 5000W in the winter with a house temperature of 20° C and 4000W in the summer with a house temperature of 25° C. Determine the minimum electric power in both cases if the year- round temperature three metres below the ground is 100 C (4 marks)

Answer 1

(cop) P-1 =(CoP)Ref Coo 2.C 20 C 20+293) 20-1o 个 5000 waft 2.93 29.3 29.3= s000 wm- S000-170.64 309140 64 29.3

10 2.5十243 15 960 = 19.866 4000 19.86 25 Win 20). 33 watt 二