The application of the deep well pump

- 2021-10-22-

Deep well pump is a water lifting machine directly connected by motor and water pump. It is suitable for extracting groundwater from deep wells, and can also be used in water lifting projects such as rivers, reservoirs and canals. It is mainly used for farmland irrigation and water for people and livestock in Plateau and mountainous areas, as well as water supply and drainage in cities, factories, railways, mines and construction sites. Because the deep well pump is operated by the motor and water pump body directly submerged in the water, its safety and reliability will directly affect the use and working efficiency of the deep well pump. Therefore, the deep well pump with safe, reliable and high performance has also become the first choice.

In the ground water source heat pump air conditioning system, the water supply of one deep well pump can often meet the water demand of two or more heat pump units. However, in the actual operation, it is found that the heat pump unit operates at part load most of the time, while the deep well pump has been operating at full load, resulting in a large increase in electricity and water charges.

With its remarkable energy-saving effect and reliable control mode, variable frequency speed regulation technology is widely used in water pumps and fans in air conditioning system, and its technology is also relatively mature. However, the application of deep well pump water supply in groundwater source heat pump air conditioning system is rare, but it is quite necessary. The pilot investigation on the application of ground water source heat pump in Shenyang shows that in the ground water source heat pump air conditioning system, when the heat pump capacity is small, the water supply of one deep well pump can meet the water demand of two or more heat pump units. In the actual operation, it is found that the heat pump unit operates at part load most of the time, while the deep well pump has been operating at full load, resulting in a large increase in electricity and water charges. Therefore, the application of deep well pump variable frequency speed regulation water supply technology in groundwater source heat pump system has great energy-saving potential.

Temperature difference control method is adopted for deep well pump. Since the outlet water temperature of the evaporator must not be too low under the heating condition of the heat pump unit, a temperature sensor is set on the return water pipe of the deep well pump, and the set temperature is TJH. When the return water temperature at the water source side of the well is greater than TJH value, the deep well pump controller sends a signal to reduce the current frequency to the frequency converter. The frequency converter will reduce the frequency of the input power supply, the number of revolutions of the deep well pump will be reduced accordingly, and the water supply volume, shaft power and motor input power of the pump will also be reduced, so as to achieve the purpose of energy saving. When the return water temperature at the water source side is lower than the TJH value, increase the frequency regulation