The application of deep well pumps
A deep well pump is a water lifting equipment that works by directly connecting an electric motor and a water pump into the water. It is suitable for extracting groundwater from deep wells and can also be used for water lifting projects in rivers, reservoirs, water channels, etc. It is mainly used for irrigation in farmland and for human and animal use in high-altitude mountainous areas, and can also be used for drainage in cities, factories, railways, mines, and construction sites. Due to the fact that deep well pumps are operated by the motor and pump body directly submerged in water, their safety and reliability will directly affect their use and work efficiency. Therefore, deep well pumps with high safety and reliability performance have become the preferred choice.
In underground water source heat pump air conditioning systems, the water supply of one deep well pump can often meet the water demand of two or more heat pump units. However, in actual operation, it was found that the heat pump unit was mostly operating at partial load, while the deep well pump was always operating at full load, resulting in a significant increase in electricity and water bills.
Variable frequency speed regulation technology is widely used in water pumps and fans in air conditioning systems due to its significant energy-saving effects and reliable control methods, and its technology is also relatively mature. However, its application in deep well pump water supply in underground water source heat pump air conditioning systems is still rare, but it is quite necessary. A pilot survey on the application of underground water source heat pumps in the Shenyang area found that in the underground water source heat pump air conditioning system, when the capacity of the heat pump is not large, the water supply of one deep well pump can meet the water demand of two or more heat pump units. In actual operation, it was found that the heat pump unit operated at partial load for most of the time, while the deep well pump continued to operate at full load, resulting in a significant increase in electricity and water costs. Therefore, the application of deep well pump variable frequency speed regulation water supply technology in underground water source heat pump systems has great energy-saving potential.
The deep well pump adopts temperature difference control method. Due to the fact that the heat pump unit must ensure that the outlet temperature of the evaporator cannot be too low under heating conditions, a temperature sensor is installed on the return water pipeline of the deep well pump, with a set temperature of tjh. When the temperature of the return water on the water source side of the well is greater than the tjh value, the deep well pump controller sends a signal to the frequency converter to reduce the current frequency. The frequency converter reduces the frequency of the input power supply, and the speed of the deep well pump correspondingly decreases. The water supply, shaft power, and motor input power of the pump also decrease, thus achieving the goal of energy conservation. When the temperature of the return water on the water source side is lower than the tjh value, increase frequency regulation.
Article source: Baidu Baike excerpt
