污垢对污水源热泵系统性能影响

Research of system performance of sewage-source heat pump with fouling effect

为保证寒冷环境下污水生物处理顺利进行,根据哈尔滨某制药厂的实际情况,提出以处理后污水为热源的污水源热泵系统,用以加热原生污水.而污垢问题是污水源热泵设计和推广使用的难点和重点.讨论污垢与换热的理论关系,并详细模拟污垢热阻变化对该污水源热泵系统性能的影响.模拟和分析结果表明,换热器的淋激式结构适合污水环境,污垢对换热的影响不仅与污垢热阻有关,还与传热系数的大小有关.污垢热阻增加,系统能效比减小,制冷剂质量流量减少,冷凝器侧污水出口温度降低,当该温度低于30℃时应考虑除垢.污垢热阻从0增加到5.28×10-4m2.K/W,压缩机输入功率增大18.02%.污垢热阻越小,制冷剂就可以以越低的平均温度提升污水温度.

In order to ensure successful sewage treatment with biological method in cold climate, a sewage - source heat pump system using disposed sewage as heat source to heat raw sewage was presented according to the status of sewage treatment in one medicine factory in Harbin, China. The problem of fouling is critical and difficult in designing and popularizing sewage -source heat pumps. The relationship between fouling and heat exchanging was discussed, and the performance of this system with the change of fouling thermal resistance was simulated. The results show that spray heat exchanger is suitable for sewage - source heat pump, and fouling impact on heat transfer is not only decided by fouling thermal resistance, but also related to heat transfer coefficient. It can be simulated that with the increase of fouling thermal resistance, system energy efficiency ratio and mass flow rate of refrigerant will reduce, and the sewage temperature of condenser outlet will decrease. It is necessary to remove fouling when this temperature is lower than 30℃. When fouling thermal resistance increases from 0 to 5.28 × 10^-4 m^2 . K/W, The analytical results also indicate that less the erant can heat up sewage with. the input power of compressor will increase by 18.02%. fouling thermal resistance is,lower average temperature refrigerant can heat up sewage with.