闭式冷却塔直接供冷及其经济性分析
Direct cooling by a closed cooling tower and its economic analysis
摘要：
对过渡季或全年需要供冷的空调系统，提出了在室外环境湿球温度比系统要求的冷水温度低3～5 ℃时制冷机停止运行，利用蒸发冷却技术由闭式冷却塔直接为系统提供冷量的节能方案；采用对数平均温差法计算得到了系统转换为直接供冷模式的工况条件；实例分析表明,采用闭式冷却塔在主机不运行工况下直接供冷节能效果明显，增加的设备投资可在两年内收回，具有较好的经济效益。
Abstract：
Puts forward the energy saving scheme using evaporative cooling where the closed cooling tower serves for air conditioning systems directly without operation of refrigerating machines when the outdoor wet-bulb temperature is 3~5 ℃ lower than the required chilled water temperature in transition seasons even the whole year. Obtains the condition of the system shifting to the direct cooling operating mode by using logarithmic mean temperature difference method. The case analysis result indicates that the effect of energy saving is obvious when the direct cooling mode is adopted under the condition without operating the refrigerating machine, and that the additional equipment investment can be recovered in less than two years, with a better economic benefit.
Keywords:evaporativecooling,closedcoolingtower,directcooling,energysaving