| The resources and energy utilization level have bigger difference compared to thedeveloped country, this means it is important to take the road of energy-saving andsuatainable development. In recent years, the situation of energy shortage is grim, thisprompte state to propose higher standard of energy efficiency of the air-conditioner.How to improve the efficienncy of household air-conditioner and relieve the costpressures of air-conditioner manufacturing enterprise has become an imortantdevelopment goal of air-conditioner industry. Micro-channel heat exchanger as a kindof compact heat exchanger, has bigger unit volume heat exchanger area comparedwith the traditional heat exchanger and reduce the heat exchanger material cost.Micro-channel heat exchanger has been widely used in automobile air-condition andpromoted using in household air-conditioner.The simulation and experimental research of the operation characteristics atsteady state for household air-conditioner using micro-channel heat exchanger arecarried out in this paper. The research object is a household split air-conditioner withmicro-channel heat exchanger. For the specific micro-scale channel and louver finsstructure in the micro-channel heat exchanger, an appropriate mathematical model ofthe flow and heat transfer has established, and the mathematical model of othercomponents of the prototype system has also established;based on the systemsimulation model, coupling the various components of the system,and establishing thesimulation model of the household air-conditioner prototype used micro-channel heatexchangers in steady-state.In order to optimize the heat exchanger and the system performance, this paperstudied the air-side and refrigerant-side flow and heat transfer characteristics ofmicro-channel heat exchanger by numerical simulation. It analyzed the influence ofthe wind speed and the structural parameters (such as fin pitch, louver pitch, louverangle and so on) to the air-side flow and heat transfer characteristics of themicro-channel heat exchanger, and evaluated the optimization scheme using thecomprehensive performance coefficient. Then, the influence of refrigerant type,refrigerant mass flow rate, micro-channel size and heat exchanger arrangement angleto the refrigerant-side flow and heat transfer characteristics of micro-channel heatexchanger has analyzed. Based on the above analysis of numerical simulation of heat exchanger, using the simulation model of prototype system, an analysis of refrigerantmass flow and air face velocity to the performance of prototype system has carriedout.In order to study the performance and operational characteristics of householdair-conditioner used micro-channel heat exchanger, the experiment research hascarried out, and the experiment was carried in the Enthalpy-difference laboratory. In astable air-conditioning condition, an analysis of the influence for the volume ofrefrigerant charge and capillary specifications to the prototype system performance,and standard tests has carried out to the prototype. The analysis results show that thenumerical simulation results and test results have a good consistency; In addition, theuse of micro-channel heat exchanger in the household air-conditioner has a goodoverall performance in comparison with the prototype, the cooling capacity and EER(energy efficiency ratio) improved. |
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