What is the operating point of the pump?
The operating point of a water pump refers to the operating state point corresponding to the actual parameter values of the flow rate, head, shaft power, efficiency, and allowable suction vacuum when the water pump is actually running in a determined pipeline system. These parameter values will plot the working state of the water pump on the head curve, power curve, and efficiency curve to form a specific point, which is the operating point of the water pump. It reflects the instantaneous working condition of the water pump and is a comprehensive reflection of the performance of the water pump and the characteristics of the pipeline system.
There are two main factors that determine the operating point of the water pump:
The inherent working capacity of the water pump: This includes the design flow rate, design head, rated power, etc. of the water pump, which is the basis of the performance of the water pump itself.
The working environment of the water pump: This includes boundary conditions such as the layout of the pipeline system and the water level changes of the pool or water tower. These conditions will affect the actual working parameters of the water pump, thereby changing the operating point of the water pump.
In actual applications, different types and uses of water pumps may have different operating point representations. For example, vane pumps such as centrifugal pumps usually express the operating point in terms of flow rate and corresponding head; while positive displacement pumps such as reciprocating pumps may express it in terms of pressure difference and corresponding flow rate. At the same time, in order to determine the operating point of the water pump, it is usually necessary to calculate the intersection based on the performance curve of the pump and the resistance curve of the pipeline system.
It should be noted that the operating point of the water pump is not fixed. With the changes in the characteristics of the pipeline system (such as the adjustment of the valve opening, the change of pipeline resistance, etc.), the operating point of the water pump will also change accordingly. Therefore, in actual operation, it is necessary to monitor and adjust the operating point of the water pump according to the specific situation to ensure that the water pump always operates under the best working conditions.
In addition, the influence of the operating point should also be considered for the selection of supporting power for the water pump. In order to ensure that the water pump can start smoothly and run stably, the power of the power machine should be slightly greater than the power required by the water pump, generally about 10% higher. If there is already a power machine, it is necessary to purchase a matching water pump according to the power of the power machine.
