The characteristics of the submersible sewage pump are: simple structure, light weight, easy assembly and disassembly, and convenient maintenance. Its flow rate is greater than the sewage pump of the same power, and less than the sewage pump of the same power; the head is at the same sewage pump of the same power, and higher than the sewage pump of the same power. It has been widely used in rural electromechanical drainage. Therefore, it has great significance and potential for energy-saving retrofit of submersible sewage pump.

Here are some of the problems in the submersible sewage pump, which are described as follows: 1. Bottom valve, filter The bottom valve is a pipe attachment installed on the water inlet pipe. Before the pump starts, the anti-leak valve is installed to eliminate the air in the inlet pipe and the water pump; when the machine is stopped, the bottom valve can automatically close the valve by the return water in the pipe. The filter screen is a trash rack installed at the bottom valve or the inlet pipe. Its function is to prevent water and other debris from entering the pipeline pump, so as to avoid blockage of some pipelines and impellers. Due to the presence of the bottom valve screen, the flow pattern is affected and local losses are formed. The local loss coefficient of the bottomed wide screen and the bottomless valve screen differs greatly, that is to say, the head loss varies greatly, and the local loss coefficient of the straight pipe inflow is significantly different from the first two local loss coefficients.