Energy efficiency technique analysis of indirect sewage source heat pump unit

Analyses the energy efficiency techniques for the unit, including raising compressor efficiency, improving working conditions of the compressor, reducing heat transfer temperature difference and returning lubricant or refrigerant by ejector. The theoretical calculation results show that the performance coefficient of the indirect sewage source heat pump unit under cooling and heating conditions can increase by about 20% and 17% respectively，compared with the general sewage source heat pump unit.