Abstract:Constant pressure water supply is a water supply mode of water conservancy system. Water supply is an indispensable part of national production and life. When the water pressure is unstable, it will result in many problems. Constant pressure water supply can keep the pressure of water supply constant, which can keep the balance between water supply and water consumption. In public waterworks, hot water heating system, municipal, hotel and building water supply system, constant pressure water supply system is essential.
Keywords: GD300-16, HVAC, VFD, Constant pressure water supply
Photo-1: constant pressure water supply application
In the constant pressure water supply system, normally includes water pumps, pressure sensor, control module, pipe part, and water tank. In the last generation system, the motor use start-delta start mode, also use the PLC to control the contactors. With technology upgrading, the new water supply system use variable frequency drive to drive water pumps, no need to use controller anymore, all control logics are integrated in VFD.
2.Variable frequency constant pressure water supply:
Variable frequency speed regulation technology is a new mature AC motor step-less speed regulation technology, which is widely used in the field of speed control, especially in the water supply industry with its unique and excellent control performance. Due to the special needs of safety production and water supply quality, the constant pressure water supply pressure has strict requirements, so the frequency control technology has been more in-depth application. The constant pressure water supply mode has the advantages of advanced technology, constant water pressure, convenient operation, reliable operation, energy-saving, and a high degree of automation.
Photo-2: Water supply process flow
3.INVT GD300-16 HAVC VFD
GD300-16 VFD drive for HVAC is developed according to HVAC application features and control requirements, and can be widely used in heating and water supply. Many special functions are developed on the basic industry applications and the energy saving is efficient.
4.Advantage of variable frequency constant pressure water supply
a. Keep the water pressure constant;
b. The control system can be operated manually / automatically
c. Automatic switching operation of multiple pumps;
d. System sleep and wake-up: when the outside world stops using water, the system is in sleep state, and it will wake up automatically when water is needed;
e. Adjust PID parameters online;
f. Pump group and line protection detection alarm, signal display, etc.
The actual pressure of the pipe network is compared with the given pressure after feedback. When the pressure of the pipe network is insufficient, the frequency converter increases the output frequency, the speed of the pump speeds up, and the water supply increases, forcing the pipe network pressure to rise.
One customer in Vietnam adopts one GD300-16-011G/015P-4 to drive 4pcs 15kW 380V water pumps, customers use this system for aquaculture application.
Photo-4: GD300-16 water supply system wiring diagram
Photo-5: GD300-16 for aquaculture application in site
After adopting the new GD300-16 HVAC VFD constant pressure water supply system, customers reduced the cost of investment, and all water pumps stat smoothly, can be controlled manually or automatically, increased water pumps lifetime and reduced electricity consumption. GD300-16 constant pressure water supply system also can be used in fire stations, property companies, fire protection construction units, and other residential quarters, business office buildings, hotels, restaurants, shopping malls, large supermarkets, subways, stadiums, etc.