Study on Heat and Mass Exchange of Heat Compensation Tower Based on Energy Transfer and Energy Analysis

Abstract

Heat pumps are often used to extract heat from soil or groundwater for constructions in cold areas. If the temperature of soil or groundwater cannot be restored in summer, it will cause cold accumulation [1], which makes the heat pump system decline in long-term operation performance. In order to solve this problem, many scholars propose to compensate the heat for soil or groundwater during summer and transition seasons. At present, the commonly used methods of heat compensation include solar energy, boiler and electric heating. However, these methods have their own disadvantages. Therefore, Deng et al. proposed that the reverse use of cooling tower as heating tower in summer compensating heat for groundwater [2]. The direct contact of air and water can not only alleviate the cold accumulation, but also reduce the urban heat island effect. In order to improve the thermal performance of the heating tower, it is particularly important to analyze the energy exchange and transfer process in the heat compensation tower. Energy analysis method is often used to analyze energy consumption of energy systems. Based on the first law of thermodynamics, this method focuses on the quantity of energy rather than the change of energy quality. Few studies have been done on the exergy transfer process of heat and mass exchange in heat tower [3-6]. In this paper, air initial state is taken as the reference point to analyze the transfer process of heat and mass exchange between air and water. From the perspective of exergy analysis, the feasibility of heat compensation tower to raise the temperature of groundwater is explained, which provides theoretical support for future research.