应用于数据中心冷却的空气制冷循环系统性能分析

本文提出一种适用于数据中心冷却的空气制冷循环系统,采用数值模拟的方法研究了压比π、环境温度（室外环境温度Tk、室内制冷温度T0）、转动部件效率（压气机效率ηc、膨胀机效率ηt）对循环性能的影响规律及系统优化途径,并分析了由空气制冷与自然冷却组成的复合系统在典型气候区城市的适用性。结果表明：实际空气制冷循环存在最佳压比,其值介于1.5~2.0之间;循环单位制冷量、制冷性能系数COP随Tk的降低或T0的升高而增大;相比于压气机,膨胀机效率对系统性能的提升更为关键;在实际循环（ηc=ηt=0.8）的最佳压比工况下,增加回热可使制冷COP提升22%;复合系统在呼和浩特运行的AEER可达14.61,表明其在全年自然冷却时长较长的地区更具优势。     

Cooling load and coefficient of performance optimizations for real air-refrigerators

Based on a simple irreversible variable-temperature heat reservoir air (Brayton) refrigeration cycle model, a performance analysis and optimization of a real air refrigerator is carried out using finite-time thermodynamics. To maximize the cooling load and the coefficient of performance (COP) of the cycle, the allocation of a fixed total heat-exchanger inventory and thermal-capacity rate matching between the working fluid and heat reservoirs are optimized, respectively. The influences of pressure ratio, the total heat-exchanger inventory, the efficiencies of the compressor and expander, the thermal capacity rate of the working fluid and the ratio of the thermal-capacity rates of the heat reservoirs on the performance of the cycle are shown by numerical examples. The results obtained provide guidances for the design of practical air-refrigeration plants.     

600MW空冷汽轮机低压部分的装配研究

新一代600MW空冷机组在结构上做了很大改进,其装配在国内尚无先例。借鉴600MW湿冷汽轮机组的装配经验,对600MW空冷汽轮机组的装配进行探讨。