Papers by Keyword: Heat Transfer Area

Abstract: A structural optimization and efficient tubular heat exchanger was designed. Compared with the ordinary heat exchanger on aspects of heat transfer area, heat loss and the structure, this kind of heat exchanger has the advantages of compact structure, high efficiency, low emissions as well as the function of temperature automatic adjustment, so it is of great promotional value.

Abstract: We used the industrial gas waste heat as the heat source of low-temperature floor radiant heating system to save energy and protect our environment, which is the thing that predecessors didn’t do. So we designed heat exchangers, which are the key parts of them, and accurately calculated their heat transfer area by using the method of ε-NTU. Through temperature drop and pressure of the gas changed, we compared their variable quantity, and draw the conclusion that improving the temperature and pressure can reduce it effectively. Using this technology, we can save 30000 tons of anthracite into a heating season , which is worth ￥24,000,000 or so, in the resident sub-district ,whose heating building area of 10000 m2, so the practical application of it has very well prospect, and the research based on it has strong economic significance and social significance.

Abstract: This paper establish a simulation program about the spiral condenser based on theoretical behavior of thermal parameters used R134a as refrigerant, analysis the influence of heat transfer area on refrigerant performance, and calculate best length of condenser heat transfer tube. The results show that the tread of coefficient of performance(COP) and cooling capacity of the system is similar along with the heat transfer tube length, and the research for the optimization design about spiral condenser heat exchanger provides the theoretical support.

Abstract: The optimal performance of an absorption refrigerator operating between four temperature levels with the losses of heat resistance and internal irreversibility is analyzed first by taking the total heat transfer area of heat exchangers as an objective function. The minimum total heat transfer area is described in terms of the rate of the entropy changes of four heat reservoirs, and the generally optimal relation among the cooling load, the coefficient of performance and total heat transfer area is achieved. Then, an ecological optimization criterion is proposed for the best mode of operation of the absorption refrigerator. We investigate the ecological optimization performance and derive the corresponding cooling load, coefficient of performance and entropy production rate at the maximum ecological criterion for the absorption refrigerator. A comparison of an absorption refrigerator performance under maximum ecological function and maximum cooling load conditions is presented. Effects of the cycle parameters on the ecological performance have been discussed.