Plate heat exchanger is a high-efficiency heat exchanger made up of a series of metal sheets with a certain corrugated shape. There are no available data on the corrosion effects of various harmful components in the sewage on the material of the plate heat exchanger. All these have caused great difficulties for the research of sewage heat exchanger. Different sewage water quality requires different system forms and heat exchangers. This requires long-term industry experience and the quality of the product itself. So how to choose the material of the sewage plate heat exchanger?
(1) The water temperature of the sewage from a sewage treatment plant after secondary treatment is 13-16℃ in winter and 22-26℃ in summer. Under normal circumstances, the sewage water temperature in winter in the northern region is on average more than 2O℃ higher than the ambient temperature, and the sewage water temperature in summer is on average 10 degrees Celsius lower than the ambient temperature. The use of the temperature difference between sewage and the environment to obtain heat energy has a huge energy resource prospect. For the working medium of sewage, we recommend using stainless steel 316L and 304. However, considering that there are more impurities in the sewage, the 316L material is obviously much safer than the 304 material.
(2) There are many ways to use urban sewage heat, but the most effective way is to use sewage heat pumps. In summer, the excess heat in the building is released into urban sewage through the heat pump unit. In winter, the heat of urban sewage is extracted and released into the building through the heat pump unit. The resource potential of urban sewage heat mainly depends on the temperature of sewage. The water temperature of the treated urban sewage changes within a certain range throughout the year.
(3) Sewage has been recognized by everyone as a renewable energy source for air conditioning systems in buildings, and its application in the country has gradually increased.Although the sewage source heat pump system has many advantages. Due to the particularity of sewage, it is easy to cause poor working conditions of the heat pump. The working conditions of the heat exchanger in the heat pump are even worse. When the sewage flows through the heat exchanger, the composition of the sewage is very complicated. It will cause scaling, blockage and even corrosion on the surface of the heat exchanger.