Study On The Fouling Characteristics In The Surface Of Spray Heat Exchanger In Sewage Source Heat Pump

Urban sewage is a kind of low level cold and heat source,and it can be extracted by sewage source heat pump technology for heating and cooling of a single building or even some larger building areas.In the country,the technology in the front decontamination device technology is relatively weak.To dodge the technical difficulty,indirect heat transfer mode of the secondary heat exchange is often used at water intake side.In this paper,pouring heat transfer is described.Without front decontamination devices,pouring heat transfer can exchange heat directly to avoid heat loss in the secondary heat exchange.Fouling phenomenon exists extensively in production and living facilities.Due to the above reason,the comprehensive increased cost is about 0.3% of GNP.In the practical application of sewage source heat pump technology,dirt impurities on the surface of heat exchanger will reduce heat transfer coefficient,which is not conducive to the efficient operation of the equipment.In this paper,firstly the formation mechanism and types of fouling on the metal surface of the heat transfer using spray heat transfer method were summarized.The influence factors of fouling were introduced,and the theory of sediment erosion was analyzed.Secondly,an experimental platform for fouling monitoring of spray heat exchanger was set up to study heat transfer with artificial sewage as circulating working fluid.At the same time,the fouling growth was monitored in real time.Then comparative tests were carried out by using tube flow rate of test tube,spray intensity and heat transfer temperature difference as change factors.Finally,the calculation method of the original definition was used to solve the dirtiness resistance,and methods of decontamination and anti-scaling were summarized.