热泵型蓄能多联机空调系统

Energy-storage VRF Air Conditioning System

为了提高多联机夏季运行制冷能力和COP并解决系统冬季运行因蒸发温度降低而导致的系统制热量衰减等问题,研制了一种兼具有蓄冷和蓄热功能的多联机蓄能空调系统,并进行了蓄冰、融冰释冷、蓄热、释热等运行模式下系统的性能实验研究。结果表明:在(夏季)夜间用电低谷蓄冰模式运行时间约8 h,能够蓄存380 MJ的冷量,用于增加白天运行时制冷剂的过冷度,铜管外结冰厚度约为35 mm,能够保证系统融冰供冷8 h;在释冷运行模式下机组制冷量可提高29%,COP提高到136.4%;在(冬季)夜间低谷时蓄能桶中贮存热水,白天释热运行模式下,通过提高压缩机的吸气温度/蒸发温度解决了系统制热量衰减的问题,并缓解了机组结霜现象。

In order to improve the refrigerating capacity and coefficient of performance （COP） of system in summer and reduce the damp- ing of heating capacity in winter, a novel variable refrigerant flow （VRF） system/unit with both cold and heat storage was developed in this work, and the performance of the system was experimentally investigated under the various operating modes, i.e. ice-storage, cold- release, heat-storage, heat-release. The experimental results showed that when the system worked continuously about 8 hours under the ice-storage mode （during off-peak period at night in summer）, the cooling capacity stored in the ice layer was up to around 380 MJ, which could be used to increase the subcooling degree of the system running in the day, and in case of about 35 mm of the ice thickness outside the coil, the system could work incessantly about 8 hours under the cold-release mode （during peak period of electricity）. Com- pared with the conventional air conditioning system, the cooling capacity of the system was increased by 29% and the COP was increased to 136. 4%. In winter, hot water was stored in the energy-storage tank during off-peak period at night; under the heat-release operating mode in the daytime, the problems such as heating capacity deceleration and frosting of the unit were relieved by increasing the compressor suction and evaporating temperatures of the system.