The non-negative pressure variable frequency pressurized water supply equipment is a new type of water supply developed on the basis of the traditional variable frequency constant pressure water supply system. It is not a simple combination of pumps, pipe valves, tanks and control cabinets, but a collection of machinery and electronics. High-tech products integrating information, self-control technology. With the development of the concept of non-negative pressure water supply, more and more scientific research units and production enterprises have conducted in-depth research on non-negative pressure technology, and have achieved relatively fruitful results. The domestic non-negative pressure technology is classified according to the working principle of the existing non-negative pressure water supply non-negative pressure supercharging water supply equipment on the market. The non-negative pressure frequency conversion supercharging water supply equipment system is mainly composed of variable frequency speed control water pump unit and steady current compensator. , vacuum suppressor, pressure and flow sensor, pre-pressure self-balancing device, control cabinet, filter, backflow preventer and other non-negative pressure conversion pressurized water supply equipment. According to the principle of achieving no negative pressure function, it can be roughly divided into the following forms:
(1) Control mode of steady flow compensator and vacuum suppressor for non-negative pressure variable pressure water supply equipment
When the water supply of the municipal pipe network is insufficient or the water consumption of the user is greater than the supply capacity of the municipal pipe network, the vacuum suppressor is opened, and the air enters the steady flow compensator, so that the originally closed compensator becomes a shut-off water tank, suppressing the generation of negative pressure, and The liquid level control is set in the steady flow compensator, and when it is lower than the low position, the water pump stops working.
(2) Self-controlled current limiting mode without negative pressure variable frequency pressurized water supply equipment
When the water supply to the municipal pipe network is insufficient or the water consumption of the user is greater than the supply capacity of the municipal pipe network, the feedback of the pressure sensing signal is adopted to limit the frequency converter so that the water pump does not exceed the water intake, and when the municipal pipe network water supply meets the requirements, the system recovers. normal.
(3) Pressure control point method for no negative pressure variable frequency pressurized water supply equipment
When the water supply of the municipal pipe network is insufficient or the water consumption of the user is greater than the supply capacity of the municipal pipe network, the variable-flow constant-pressure water supply pump is straightened up, and the system returns to normal after the water supply meets the requirements.
1. Flow rate: 0-5500m3/h Head: 20-250m
2. Motor power: 0.55-315KW Pressure adjustment accuracy: 0.01MPa
3, the number of pumps: single or multi-head and number of outlet pipe flow rate: 1.2-2.0m / s
4, start mode: variable frequency start Power: 380V 50Hz
5, operation mode: manual, automatic