Study Of Condensing Heat Recovery Of Central Air-condition System Combined With Variable Water Flow Technique

Condensing heat recovery is divided into part of the heat recovery and total heat recovery. The energy grade of heat recovered in the part of the heat recovery process is high, but the quality is low, on the contrary, the quality of the total heat recovery is large, but the energy grade is low. At the same time, variable flow of cold water technology has been widely used, but there is controversy in variable flow of cooling water technology.There are lots of studies about the variable flow of cold water system and cooling water system, and the heat recovery system. And the technique of variable flow of cold water system and cooling water system combined with the heat recovery system is one of the important method for energy saving. But the investigation of the combined variable flow system and heat recovery system is very rare. For example, the resistance balance between them and comprehensive control have become to a research topic for the application of the combined system. This paper has analyzed these three cases:the condensing heat recovery with variable flow of the cold water the condensing heat recovery with variable flow of the cooling water, and the condensing heat recovery with variable flow of both the cold water and cooling water. The main discussion is about the condensing heat recovery with variable flow of the cold water and cooling water. The integrated COP is employed to evaluate the combined system。The retrofit project of central air-condition system in the mall in Dazhou, Sichuan was taken as the research object, the mathematical model of the combined heat recovery and variable water flow system is given out. The tested data before retrofit and after retrofit are compared, and the energy saving potential is calculated.Research results show that there are tremendous energy saving of heat recovery with cold water variable flow technology, and energy saving potential of the heat recovery with cooling water variable flow is limited. This paper has given a guide and reference on the transformation, application and promotion of the existing water cooling central air conditioning systems.