Specialized Method of Calculating Heat Input from Wastewater in the Premises of the Sewage Pumping Stations

Modern sewage plant is a complex engineering structure with a different configuration of functional sectors (zones). The inlet sections to the pumps operate in a gravity flow mode, characterized by incomplete filling of the section with water, based on the requirements of non-absorption of ventilation safety for the resulting gas, mainly methane. As the liquid and gas have a higher temperature than the air temperature in the premises of the pumping stations. The problem of heat flow from the fluid have to be solved by a specially designed method that takes into account the separation of gas and liquid flows in pipes and rectangular channels by applying the theory of similarity, criteria equations and computational experiment. An important circumstance in the structure of the algorithm of the calculation is finding and using the concept of the wetted perimeter, as well as newly introduced in the article the concept of the average heat transfer coefficient with respect to the specific configuration of each element partially filled with liquid. Pumps and pipes after them as usual completely filled with water, but here in turn, we have to consider a special form of surfaces of equipment and fittings drainage systems. (paper)