Operating Characteristics of Different Types of Heat Recovery Systems Under Different Operating Conditions

Pengfei Wu
School of Energy and Environment,Southeast University,Nanjing 210000,Jiangsu,China
Shuhong Li
School of Energy and Environment,Southeast University,Nanjing 210000,Jiangsu,China

Abstract:

In order to study the operating characteristics of different kinds of heat recovery systems under different operating conditions, a coupling model of the run-around heat recovery system is established with MATLAB and FLUENT. The coupling model optimizes the outer part of the mathematical model of the heat recovery system, and realizes the simulation under different kinds of heat exchangers. In this paper, the coupling model is used to simulate the operation of the heat recovery system using plain fin-and-tube heat exchanger, wavy fin-and-tube heat exchanger and slotted fin-and-tube heat exchanger at different ambient temperatures, different flow ratios of ethylene glycol solution to air and different heat capacity flow ratios. The results show that the corrugated fins and flat fins are better than the flat fins. In addition, when the difference between the ambient temperature and the indoor temperature gradually increases, the heat recovery rate gradually decreases. It is found that the result of the ratio of heat capacity flow rate is similar to the result of the flow ratio of liquid to air. An optimum ratio exists for both of them, and when this optimum ratio is reached, the heat recovery rate reaches its maximum.