Sewage source heat pump in the form of many. According to heat pump directly from the sewage heat, can be divided into direct and indirect two kinds of.
Indirect sewage source heat pump is the so-called intermediate heat exchanger or heat pump loop through the water / sewage immersion heat exchanger directly absorb heat in the sewage in the sewage pool is arranged between the heat pump water loop and loop extraction. The direct sewage source heat pump is directly set up in the sewage pool directly through the heat pump or the evaporator of heat pump, and the heat in the sewage is absorbed by the refrigerant. Compared to the two, has the following characteristics:
1. Indirect sewage source heat pump is better than the direct type heat pump operating conditions, generally there is no blockage, corrosion and microbial breeding possibilities, but the middle water / sewage heat exchanger should have anti blocking, anti corrosion, anti microbial breeding etc..
2. Indirect sewage source heat pump with respect to the direct type, the system is complex, equipment (heat exchanger, water pump, etc.), so, in the case of the same heating capacity, indirect system cost is higher than the direct type.
3. In the sewage temperature at the same conditions, the direct evaporative temperature than the indirect sewage source heat pump type high 2 ~ 3 DEG C, therefore, in the case of the same heating capacity, direct sewage source heat pump than the indirect type energy saving about 7%.
In addition, also according to the characteristics of water quality, sewage source heat pump design and optimization of the sewage / refrigerant heat exchanger structure, the heat exchanger should have anti blocking, anti corrosion, anti microbial breeding and other functions, usually adopts horizontal tube (or plate) water spray, immersion type heat exchanger or dry sewage tube type heat exchanger. Due to the different heat transfer equipment, can be combined into a variety of sewage source heat pump form.
