三级蒸发冷却空调系统空气处理过程的■分析

Exergy Analysis of Air Handling Processes in Three-stage Evaporative Cooling Air-conditioning System

为优化三级蒸发冷却空调系统能量转换与利用效率,通过对其进行热力学分析,建立三级蒸发冷却空调系统空气处理过程的■分析模型。在典型工况下对系统内各级蒸发冷却器进行了■计算,获得了各级蒸发冷却过程的■损失以及系统的■效率。结果显示,系统的■效率为24.27%,一、二级间接蒸发冷却器的■损失分别占总输入■的36.98%和33.66%,第三级直接蒸发冷却器的■损失仅为5.09%。可见,三级蒸发冷却空调系统的空气处理过程的■损失,主要源于间接蒸发冷却器内热质交换过程的不完善以及二次排风的热损失。因此,提高间接蒸发冷却器有效输出■和能源利用效率是优化三级蒸发冷却空调系统的关键。

To optimize the energy transition and utilization efficiencies of three-stage evaporative cooling air-conditioning system,the exergy analysis model of air handling processes in the three-stage evaporative cooling air-conditioning system was established by thermodynamic analysis of the system,and the exergy of evaporative coolers in each stage of the system was calculated under typical operating conditions so as to obtain the exergy losses of each stage and the system exergy efficiency.Results showed that the system exergy efficiency was 24.27%,and the exergy loss of the first and the second stage indirect evaporative coolers accounted for 36.98% and 33.66% of the system total input exergy,while that of the third stage direct evaporative cooler was 5.09% only.Therefore,exergy loss of air handling processes in the three-stage evaporative cooling air conditioning system derive mainly from the defective heat and mass transfer processes and secondary exhaust air in the indirect evaporative coolers.Hence,the key to optimizing the three-stage evaporative air-conditioning system is to improve the effective exergy output and energy utilization efficiency of indirect evaporation processes.