When designing the pump station, how to determine whether the selected water beam is appropriate in advance? What is the potential capacity of the pump itself To play? Is the selected centrifugal pump safe, PJ reliable and economical? To solve these problems, it is necessary to know or determine what needs to be done The working state of the selected water pump during operation, that is to determine the condition (working point) O of the water pump Pump working condition refers to the actual: l working state of the pump device at a certain instant, and the characteristic parameters of the available pump: flow (J, lift) Program grab, efficiency V, shaft power n, allowable suction vacuum height E5, etc. If the working condition of the water pump can be calculated in advance, then All problems can be solved. Each pump has its own inherent characteristic curve at a certain speed TJ, which reflects the latent energy of the pump itself Ability to work in. This potential working capacity * of the water pump is expressed as the instantaneous actual water output of the water pump when the water pump is running 9. Lift JJ, shaft power JY, efficiency V, etc. these values are plotted on the field curve, power curve and efficiency curve A specific point, which is called the instantaneous working condition point of the water pump device. The D condition point reflects the instantaneous working condition of the water pump. In addition to the capacity of the pump itself, the specific location of the d-condition point also depends on other factors. It is conceivable that a large The water pump is installed in a pipeline system with a sewn pipeline, which can not give full play to its working capacity at all. Therefore, it is decided to pump the water There are two factors in the situation: (1) the inherent working capacity of the water pump; (2) The working environment of the water pump. That is, the pipeline system of the water pump The layout of and the boundary conditions such as the change of water level of pool and water tower. On the * side, we will discuss the factors and accuracy that affect the working point of the water pump Method of determining operating point.