solution only for part e... don't need solutions for the first four parts...

Exercise 7.1 (Ba16) An electrical heat pump is used to cool milk from 32C to 4C and to heat water from 8C to 55C. The heat pump can heat 800 of water per day at a daily milk production of 1050. a) How much electrical energy is used for the heat pump per day? b) How much entropy is produced in the heat pump per day? c) How many litres of water at 55C can be delivered by a reversibly working heat pump per day which cools the same amount of milk? d) How much electrical energy would be required by this reversibly working heat pump per day? e) How many cows does the farmer have to keep for the daily milk production of 1050 ? No heat losses to the ambience and no pressure losses in the heat exchanger have to be considered. Densities and specific heat capacities: Water:WMilk:M=1000kgm3,cW=4.2JK1g1=1030kgm3,cM=4.0JK1g1 Neglect changes in kinetic and potential energy. The system can be considered as stationary. Result a) WHP=3.68107dJ b) Sprod=1.03105dKJ c) V=641/d d) WHP=5.5106dJ e) 40 cows