36 The Thermal Performance of a Cross-Flow Plate Heat Exchanger for Indirect Evaporative Cooling

Building energy consumption takes up 27.8% of China's general energy consumption. Air-conditioning energy consumption has exceeded 50% in building energy consumption. It is fully utilized by cooling amounts of low-grade of air-conditioning, we can have a very good energy saving. This paper establishes the mathematical model of the cross-flow plate heat exchanger for indirect evaporative cooling with condensation from primary air. The mathematical model is solved according to the finite difference method. Through the numerical solution of the mathematical model, the temperature and humidity distribution of the primary air and the secondary air are obtained. The influence of the mass flow rates of primary air and secondary air, the width of the passage and the plate wettability on the efficiency of the cross-flow plate heat exchanger for indirect evaporative cooling is analyzed in this paper. Finally, experimental investigation is also carried out for validating part of the simulation model. Theory and the experiment indicate the cross-flow plate heat exchanger energy reclaiming effect reaching 80.5%.