Sensible heat recovery systems for batch processes with waste heat fluid drained at the end of the process

Abstract

Mathematical models for modelling the behaviors of heat recovery systems of batch processes with waste heat fluid drained at the end of the process were developed. The results show that the optimum heat capacity rate ratio of the feed to the drain fluids might be estimated to be unity. For the drained fluid circulated (Dc), and flowing through heat exchanger (Dt) systems, the optimum number of transfer units might be estimated to be 1 and 4, and the effectiveness increases as the heat capacity rate ratio of the feed water to the drain water decreases and increases, respectively. The drained fluid circulated with the feed flowing through the heat exchanger system provides not only the highest effectiveness but also the lowest number of transfer units. A prototype of energy recovery system for the drained water from a 30 ton/day conventional tubular ice maker was developed according to the obtained result. It shows that the system is able to increase the productivity about 1600 kg/day and decrease the energy consumption by 5%. This concept has never been found. It may be applied to recover energy from batch processes having high or low temperature fluid drain after the end of the process.