Optimal Performance Research Of Refrigerating System With Mini-channel Condenser

Micro-channel heat exchanger has been widely used in the field of automobile air-conditioning because of its characters such as much higher heat exchange efficiency, smaller size, lighter weight and less cost, and it also has broad application prospects and significant meaning in the field of home air conditioning and industrial refrigeration. Effects of the micro-channel condenser has on to the refrigerant system has been studied in this paper in order to figure out the optimized structure arrangement which can acquire a relatively higher EER. Distributed parameter method and method are used to establish a steady-state mathematical model of micro-channel condenser, and structure arrangement optimization is discussed based on this model Steady-state simulation of the refrigerant system performance with3condensers of different structure arrangement is carried out using EASY5, and some experiments are conducted to support the conclusions.Firstly, related calculation about the structure parameters such as the effective heat transfer aera and hydraulic diameter is conducted. Steady-state simulation model of the micro-channel condenser based on the energy balance theory is built by choosing the suitable correlations of heat transfer and pressure drop and distributed parameter method and the method to analyze the variation trends of the refrigerant-side heat transfer coefficient,refrigerant pressure drop and the condenser capacity along the length direction.Secondly, research on the structure arrangement optimization is discussed based on the model above. Performance of the micro-channel condenser with different numbers of passes and tubes is analyzed. The structure of the double-pieces micro-channel condenser is presented and the performance of the double-pieces micro-channel condenser and the sigle-piece micro-channel condenser with the same heat exchange aera is studied.Steady-state simulation of the refrigerant system performance with three condensers of different structure arrangement is carried out using EASY5under the same conditions in order to get the optimized system performance coefficient.Experimental research on the micro-channel condenser is also conducted using room heat balance method to prove the validation of the numerical model and the refrigerant system improvement of replacing the fin-and-tube condenser with the micro-channel condenser.