TABLE OF CONTENTS - The Professional Green Building Council

Theme A: Connecting the Pearl River Delta Regionηw—— Efficiency of power transmission,92%η y—— Electric efficiency of compressor,90%G z — Consumption of natural gas(m 3 )q —— Calm value of natural gas(KJ/m 3 ),approximate 40000 KJ/m 3rz3.2.1 Performance comparison of cooling systemsThe cooling water temperature has great impact to the chilling units. When thecooling water temperature fall down, the COP of the chilling units will increase.Fig.5 is the COP change with cooling water temperature.COP5.45.25.04.84.64.44.232 30 28 26 24 22Cooling Water Temperature ℃Figure 5: The COP change with cooling water temperature in cooling periodIn summer, the traditional air-conditioning system use cooling tower to cool water.The design cooling water temperature is 32℃.And the COP of refrigerator isabout 4.3on his condition. However, the COP is always lower than 4.3 because ofthe sustained high temperatures in Chongqing. In this project, the river water airconditioningsystem use river water cooling replace the cooling tower. The averagewater temperature is about 26℃. The minimum temperature can reach 21℃.Considering the heat loss, the cooling water temperature will be at 28℃. So theCOP average increase to 4.7, the highest COP can reach 5.2. So we can know thatthe COP can average increase 10%, at most even 20%.57