Mechanical seal manufacturer Introduce the working characteristics of parallel water pumps

Parallel connection of pumps: there are many ways to change the working conditions of the pump system, one of which is the performance synthesis of multiple pump equipment. When one pump cannot meet the working conditions, multiple pumps need to be connected in parallel or in series to obtain the desired flow and head. When the first pump is connected with the suction pipe of the second pump or multiple pumps, and the outlet pipe is also connected together, it is called parallel connection of pumps.

Can pumps with different characteristics be connected in parallel? Before answering this question, let's take a look at the situation when two pumps with different characteristics are in parallel: when the system output head reaches the maximum head of the low head pump, the system is in a critical state, at this time, the system output flow is separately supplied by the high head pump, and the output flow of the low head pump is zero. When the flow continues to decrease, Since the high lift pump forces part of the water body to flow backward through the low lift pump (if there is no check valve), circulation will form inside the system, and the pump will not work. Therefore, in general, it is not recommended to use pumps with different lift in parallel. Note that the lift should be as close as possible and the flow can be different.

Therefore, this operation mode is usually adopted in the reconstruction of pump stations. When different pumps operate in parallel, whether the two pumps can work normally depends on the flow Q0 of the pump with high dead point head and the pump with low dead point head. When the flow is less than this flow, the check valve at the outlet of the pump with low dead point lift cannot be opened normally, so no water will flow out.

Features of parallel operation of water pumps:

① The water supply can be increased, and the flow in the water transmission main is equal to the sum of the water output of each parallel pump;

② The total flow can be adjusted by starting and stopping the number of pumps to achieve the purpose of energy conservation and safe water supply.

In engineering, the water flow required by more than four hosts is very large. If only one pump is used, the pump will have a large power, high cost, large load, which is easy to impact the power grid, and the operating noise is also large, and there may not be such a large power pump; At this time, the parallel connection of pumps can solve this problem, and when the main engine is not on at the same time, several pumps can also be stopped to adjust the water flow, so as to achieve the purpose of energy conservation;

③ When one of the pumps working in parallel is damaged, the other pumps can continue to supply water. Therefore, the parallel water delivery of pumps improves the flexibility of unit operation scheduling and the reliability of water supply, and is the most common operation mode among multiple units.