Research On The Cooling Systeml Based On The Variable Primary Flow In Air-conditioning Systems

The central conditioner cooling water system were made of the heat-exchange equipment,cooling water pump and cooling tower.The cooling water system would lead to waste of electrical energy and water resource due to the unreasonable design or unsuitable operation.There is big space to save energy.To reduce the central conditioner cooling water system energy consumption,this article analyze the influence factors about energy consumption in every section through calculating,based on actual project and cooling water pump frequency energy saving condition.Take an office building in xi'an for example,this article get refrigerating parameter and parameter of the energy consumption in condition of changing cooling water pump frequency,cooling tower fan amounts and refrigerating parameters of refrigerating unit seperately,as well as recording outdoor weather parameters in complete operation cycle.Based on enthalpy potential method,this article gives calculating about the capacity of each heat exchanger of cooling tower considering outdoor weather parameters in different moment and get the capacity of each heat exchanger of cooling tower.From the result which come from calculating water pump energy consumption in different frequency,we know water pump energy consumption will reduce 23%if the frequency below 5Hz.Though analyzing experiment datas,we get connecting curves between COP,heat exchange efficiency of the cooling tower and system energy consumption under different controls by calculating refrigerating output, water pump performance and the cooling tower model of the heat interchanger.From the connecting curve,we know that:COP have the same change endency of raising in variable flow cooling water system and constant flow cooling water system,but compared to constant flow cooling water system,variable flow cooling water system COP is lower,so in the system which cooling water pump energy consumption take bigger proportion,variable flow cooling water system will consume less energy;the range of cooling tower circulating water is from 50%to 100%.corresponding to that the range of refrigeration for supply is from 73%to 100%,the cooling capability of cooling tower will go down along with circulating water dropping;When Rate of load condensate is below 50%,because of the power of water pump is small,variable flow cooling water system energy consumption and energy consumption for refrigerator are the same,enerny saving effect will be obvious,to reach 25%.