Water stored in a large, well-insulated storage tank at 21.0°C and atmospheric pressure is being pumped at steady state from this tank by a pump at the rate of 40 m3/h. The motor driving the pump supplies energy at the rate of 8.5 kW. The water is used as a cooling medium and passes through a heat exchanger, where 255 kW of heat is added to the water. The heated water then flows to a second large, vented tank, which is 25 m above the first tank. Determine the final temperature of the water delivered to the second tank.q= 8.5 kW or -8.5 kWWs= 255kW or -255kwThanks!
They are both negative in that they are adding energy to the fluid. The pump increases the pressure, that takes energy. In the heat exchanger you are also adding heat to the water so it also is negative. The temperature rise across both the pump and the heat exchanger will be positive.
