过渡季节冷却塔供冷系统的优化研究

Optimization research of tower cooling system in transient season

冷却塔供冷系统性能与所处地区气候条件及建筑负荷特点密切相关。为研究夏热冬冷地区冷却塔供冷系统的性能及影响规律,选取具有典型夏热冬冷气候特征的南京地区,建立了冷却塔供冷系统模型并进行实验验证,开展系统变工况性能与优化研究,获得了不同环境湿球温度下,末端负荷和一、二次侧水流量变化对系统二次侧出水温度的影响规律。结果表明:随着末端冷负荷及一、二次侧水流量的增大,二次侧出水温度均不断升高。冷却幅高随冷负荷的增大而增大,且随着环境湿球温度的升高,冷却幅高明显降低,冷却塔效率提高;当系统一、二次流量均为6t/h,相比环境湿球温度为12.6℃工况,环境湿球温度为16.8℃时的冷却幅高平均降低1.0℃。在同样的冷负荷情况下,二次侧流量的减小有助于冷却幅高的减小。

The performance of tower cooling system is closely related to regional climate and building load characteristics. In order to study the performance and influence rule of tower cooling system in hot summer and cold winter zone, a mathematic model was established and its accuracy was proved by experiment. Optimization research of tower cooling system was carried out in differ- ent operation conditions based on the climate in Nanjing where had the typical climate characteristics of hot summer and cold win- ter zone, and the influence rules of the cooling load and water flow on supplied water temperature of secondary circuit were ob- tained by simulation. Results indicate that the supplied water temperatures of secondary circuit all increase with the increase in cooling load and water flow. Cooling approach increases with the increase in cooling load and decrease in ambient wet bulb tem- perature. The cooling approach under the ambient wet bulb temperature of 16.8℃ reduces 1.0℃ compared with that of 12.6℃, when the water flow of primary and secondary circuits is 6t/h. Reducing the water flow of secondary circuit contributes to the reduction of cooling approach at the same cooling load.