Study On Heat Transfer And Flow Characteristics Of Parallel Flow Condenser Of Bus Air Conditioning

As the key heat exchanger equipment of bus air conditioning, the structure size and heat exchang performance of condenser have important impact on the layout,function characteristic and economy of bus air conditioning. In this paper, for 12-meter bus air conditioning system of Yangzhou Jiexin Auto Air-conditioner CO.,LTD,take thermodynamics and heat transfer as the base,simplify,analyze.use the Matlab software to establish the components of bus air conditioning system numerical calculation model, focus on simulation studying on parallel flow condenser condense. For each process,take a flat tube for the study,along refrigerant flow direction,the pipe will be divided into a number of micros, from one of the micro-control body, the establishment of air side and refrigerant side single-phase zone, analysize the flow characteristics. Using tools in Matlab to optimized simulate the model of the bus air conditioning, Access the main performance parameters of changes of bus air conditioning in used the parallel flow condenserprovide the basis for matching design of bus air conditioning system. And the bus air conditioning system performance experiment is done on the roof-mounted bus air conditioning performance experiment system, the experimental results verify the model of rationality and reliability.The result shows that the parallel flow condenser has better performance, For parall flow type condensers, the louvered fin is adopted for air side and the micro channel with rect angle sections and small hydraulic diameter is adopted for refrigerant side. Then the mathematic model was established to simulate the performance of thecondenser. The results show that during the process of flow and condensation of the refrigerant, surface tension plays a significant role in the enhancement of heat transfer. In the parallel flowtype condenser with gradually decreasing flow section areas, it can keep high heat transfer coeficient and low pressure,also verified the numerical analysis tools has an important project value.