Adsorption Refrigeration and Indirect Evaporative Cooling--A Double-Effect Hybrid Vehicular Air Conditioning System

摘要

Present technologies, which use either solid adsorption or solid-desiccant indirect evaporative cooling cannot meet refrigerating capacity needs. To address this, we have introduced a new double-effect hybrid air conditioning system. In this paper we establish a model for a double-effect hybrid air conditioning system, which combines the technologies of adsorption refrigeration using zeolite 13X-water as the working pair and indirect evaporative cooling, so that it can be used in commercial and combat vehicles. We establish two-dimensional (2-D) mathematical model of the adsorbent bed and model of indirect water evaporative cooling system. Experiments were carried out for the purpose of simulating the adsorption refrigeration cycle, verifying the physical and mathematical models, determining boundary conditions, measuring the cooling capacity of the refrigeration cycle and verifying the efficiency of the double-effect hybrid automotive air conditioning system combining adsorption refrigeration and indirect evaporative cooling. By analyzing the theoretical aspects of this system, together with numerical simulation and experimental research, we find out that this system is feasible in overcoming the low cooling capacity and low coefficient of performance (COP) of a system that only uses solid adsorption refrigeration. The desorption rate of this doubleeffect hybrid vehicular air conditioning system is 14% faster than that of a solid adsorption refrigeration system, and the cooling capacity of this double-effect hybrid system is 10% greater than that of a solid adsorption system. Indirect evaporative cooling increases fresh air quantity, thus improves air quality. The double-effect hybrid automotive air conditioning system has various advantages, especially in improving the coefficient of the refrigeration cycle, for the following reasons: the condensing of the adsorbent and the condenser can be strengthened by cooling air from an indirect evaporative cooling system. Another portion of the cooling air from the indirect evaporative cooling system can be directed to the area that needs air conditioning This portion has the function of exchanging air at a constant temperature, improving air quality, and assuring the safety and health of people.