Super-wide-range precision quantitative adjusting valve, flow control system and flow control method

Abstract

The invention discloses a super-wide-range precision quantitative adjusting valve, a flow control system and a flow control method. The super-wide-range precision quantitative adjusting valve comprises an angular travel electric executing mechanism, a connector, a valve body, a valve rod for driving a valve element to move, and the specially-made valve element arranged in the valve body. A switching-on part and a switching-off part are arranged on the valve element, and a through flow hole is machined in the switching-on part. When the valve rod drives the valve element to rotate to be switched on from being switched off, the rotating angle increment of the valve element is delta theta, the switch-on amount increment of the through flow hole in the valve element is delta S, delta theta / delta S is equal to K, and K is a constant. The structure is simple, mounting and using are convenient, the valve has the beneficial effects that super-low flow control is achieved, the control precisionis extremely high, and the range ratio is large by guaranteeing that the flow sectional area of the valve and the rotating angle of an angular travel adjusting valve are in a linear scale relationship, the adjusting valve is used as the flow precision control executing mechanism, and the precision flow quantitative control system is formed by the adjusting valve, a flow controller, a power drivesource and a flow meter.

Description

technical field [0001] The invention relates to a quantitative regulating valve, which belongs to the technical field of valves, in particular to an ultra-wide range precision quantitative regulating valve, a flow control system and a flow control method including the regulating valve. Background technique [0002] At present, industrial control generally uses electric control valves as the final execution part of automatic control. The valve opening can meet the control requirements from 25% to 80%. When the valve opening is below 25%, the valve is basically closed, but once the valve is opened , under the impetus of pipeline pressure, even a small-caliber fine and small single-seat straight-through valve (the flow coefficient of the DN10 caliber regulating valve KV=1.6), the starting point of the flow through the valve can reach several hundred liters / hour; The theoretically designed adjustable ratio of the valve is 30:1, but the actual adjustable ratio can only reach abou...

AI Technical Summary

Problems solved by technology

[0007] 1. The quantitative control accuracy of the metering pump is not high (5%). The actual delivery flow of the metering pump, especially the domestic metering pump, is compared with its theoretical calculation value. There is a serious nonlinearity. The metering pump runs for a long time, and the deterioration of the diaphragm also leads to the distortion of the flow characteristics.

[0008] 2. The metering pump is a volumetric pump with continuous reciprocating operation. As the running time of the metering pump continues to increase, the mechanical wear will increase, and the degree of diaphragm deterioration will also increase (generally, the diaphragm needs to be replaced every two years), so the maintenance cost is high. limited lifespan

[0009] 3. Another fatal weakness of the metering pump is that the range is still limited (maximum 10:1), so that the large metering pump cannot complete the small flow control, and the small-range metering pump cannot complete the delivery of the larger flow

Generally, the fluctuation is large, so there are many problems in using metering pumps as precision flow control

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