Solution of Laeg LD300 variable frequency and constant pressure water supply system

I. Overview of Constant Pressure Water Supply System

Constant pressure water supply system is the main component of domestic water supply at present, which refers to the control mode that the outlet pressure is kept constant by detecting the pressure of the pipe network and adjusting the output of the motor and pump when the water consumption changes in the water supply network.

Generally, when selecting water pump, water supply system will consider leaving a certain margin. However, in the actual process of water use, the water consumption changes greatly, and traditional water supply systems all use valves to adjust the flow. This regulation mode makes the motor always run under full load condition, which causes huge waste of electric energy and frequent maintenance of equipment.

Second, the working principle of constant pressure water supply system

Constant pressure water supply system detects the pressure value of pipe network through pressure sensor, and feeds it back to the frequency converter in the form of current or voltage signal. Through the built-in PID function of the frequency converter, the output speed of the motor is adjusted by comparing the difference between the current feedback pressure and the set pressure, and even the motor is instructed to sleep under the condition of little water use, so as to achieve the purpose of constant pressure and energy saving.

Third, the advantages of frequency conversion and constant pressure water supply

3.1 Shenzhen Laeg inverter has built-in PID and sleep wake-up function, which can automatically adjust the output frequency according to the setting, keep the pressure of the pipe network constant, and do not need frequent operation by operators, thus reducing the labor intensity of personnel and saving manpower.

3.2 During the operation of frequency conversion constant pressure industrial and commercial system, the rotation speed of the motor and pump is determined by the external water supply, so that adjusting the rotation speed of the pump can change the outlet pressure of the pump, which has the effect of reducing the pipeline resistance and greatly reducing the interception loss compared with the way of controlling the outlet pressure of the pump by adjusting the valve, so the system can save considerable electric energy in the operation process and benefit for a long time;

3.3 Shenzhen Laeg inverter can independently select the starting curve of 16-speed according to the customer's demand, so as to avoid the motor starting.

The current shock also avoids the impact on the equipment, eliminates the water hammer phenomenon and increases the service life of the water pump;

3.4 Frequency conversion and constant pressure water supply system, when the external water supply is less than the rated flow, the pump speed decreases, which reduces the wear and heat of bearings and prolongs the mechanical service life of pumps and motors.