JP3936051B2 - Pressure reducing valve with flow measurement function - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressure reducing valve that is attached to a piping system such as steam, compressed air, liquid, etc., and maintains the fluid pressure on the outlet side, that is, the secondary side of the valve at a constant set pressure, and in particular, measures the flow rate of the pressure reducing valve. It has a function that can be performed.
[0002]
[Prior art]
As a conventional pressure reducing valve capable of measuring a flow rate, for example, there is one disclosed in JP-A-63-45614. This is provided with a displacement detector that detects the displacement of the main valve body of the pressure reducing valve, detects the displacement of the main valve body, that is, the opening degree by this displacement detector, and flows down the pressure reducing valve based on this valve opening degree. The flow rate can be measured.
[0003]
[Problems to be solved by the invention]
In the above-mentioned conventional one, a displacement detector for detecting the opening degree of the main valve body has to be provided, and there is a problem that the mechanism of the pressure reducing valve becomes complicated.
[0004]
Accordingly, an object of the present invention is to obtain a pressure reducing valve with a flow rate measuring function which can measure a flow rate with a simple structure.
[0005]
[Technical means for solving the problems]
The means of the present invention devised to solve the above problems is to detect the fluid pressure on the outlet side of the valve, that is, the secondary side with the pressure detecting means, and open and close the valve portion via the pressure detecting means and the pressure responsive member. The pressure reducing valve is supplied from the opening of the pressure reducing valve and the pressure on the primary side and the secondary side to supply or stop the high pressure fluid on the primary side to the secondary side and maintain the fluid pressure on the secondary side at a predetermined value. The valve portion connected to the pressure responsive member is arranged, the valve portion is urged in the valve closing direction by an elastic member, and the pressure applied to the pressure responsive member is A pressure detection means for detecting, a calculation unit for converting the detected pressure from the pressure detection means into a load and calculating the opening of the valve unit from the canceling relationship with the elastic force of the elastic member; The flow rate at which the pressure reducing valve flows down from the opening of the valve section and the primary and secondary pressures It is intended to calculate.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
As is well known in the art, the flow rate flowing down the valve is a constant based on the type of fluid flowing down, the pressure difference between the primary side and secondary side of the valve is ΔP, and the valve opening is a parameter. The inherent capacity coefficient is Cv, and the flow rate can be calculated by the equation Q = k · Cv · ΔP1 / 2.
[0007]
Cv is obtained by calculating ΔP from the pressure on the primary side and the secondary side, and calculating the opening degree of the valve portion from the canceling relationship between the pressure from the pressure detecting means of the pressure responsive member and the elastic force of the elastic member. The flow rate Q flowing down the pressure reducing valve can be calculated using the above formula.
[0008]
For example, when a coil spring is used as the elastic member, the load by which the valve portion is biased in the valve closing direction by the coil spring and the load by which the pressure responsive member opens the valve portion due to the pressure applied to the pressure responsive member are balanced. That is, the opening degree of the valve portion is determined by canceling. Therefore, when the pressure receiving area of the pressure responsive member is constant, the load at which the pressure responsive member opens the valve portion is calculated by detecting the applied pressure, and it is assumed that the coil spring is bent by an amount corresponding to this load. The displacement amount of the coil spring, that is, the opening degree of the valve portion can be calculated.
[0009]
【Example】
FIG. 1 shows an overall configuration diagram of a pressure reducing valve with a flow rate measuring function of the present invention.
The pressure reducing valve main body 1 is provided with an inlet 2 and an outlet 3, and the inlet 2 is connected to a steam source (not shown) by a pipe line 30. A pressure sensor 31 as a pressure detecting means for detecting the primary pressure is attached to the pipe line 30. On the other hand, a pressure sensor 5 for detecting the secondary side pressure is attached to the pipeline 4 provided at the outlet 3.
[0010]
The pressure reducing valve body 1 is provided with a main valve body 7 and a main valve port 8 as valve parts via swirl vanes 6. A float 9 is disposed in the float cover 10 in a free state below the swirl blade 6. A float valve body 11 is attached below the float 9. A coil spring 12 as an elastic member is disposed below the main valve body 7 as a valve portion, and a slide bar 13 is provided so that the main valve body 7 is slidably attached up and down. The coil spring 12 is arranged so as to bias the main valve body 7 in the valve closing direction, that is, the main valve port 8 side.
[0011]
A piston 14 as a pressure responsive member, a pilot valve 15, and a diaphragm 16 as a pressure detection means are arranged above the main valve body 7, respectively. A pressure sensor 32 as pressure detection means is attached to the space 33 above the piston 14. The pressure applied to the piston 14 is detected by the pressure sensor 32.
[0012]
A coil spring 17 for setting pressure, an adjustment screw 18 for adjusting the amount of compression of the coil spring 17, and a motor 19 for moving the adjustment screw 18 up and down while rotating are provided on the upper portion of the diaphragm 16. The adjustment screw 18 is moved up and down by the rotation of the motor 19 and the compression amount of the coil spring 17 is changed, whereby the spring force for pressing the diaphragm 16 downward is changed, and the secondary side pressure of the pressure reducing valve is changed to a predetermined pressure. Is set to a value.
[0013]
The inlet 2 side and the pilot valve 15 part communicate with each other via the communication path 25, the pilot valve 15 part communicates with the space 33 via the communication path 26, and the lower space 20 of the diaphragm 16 communicates with the outlet 3 side via the communication path 21. To do. The pressure on the outlet 3 side, that is, the secondary pressure of the pressure reducing valve is transmitted to the lower part of the diaphragm 16 through the communication path 21 and is maintained by itself at a pressure value balanced with the spring force of the coil spring 17.
[0014]
The primary pressure of the pressure reducing valve is detected by the pressure sensor 31, the secondary pressure is detected by the pressure sensor 5, and the pressure in the space 33 added to the piston 14 as a pressure responsive member is detected by the pressure sensor 32. Are sent to the controller 22 respectively. Although not shown in the controller 22, a storage unit is provided, the relationship between the capacity coefficient Cv and the opening degree of the main valve body 7, the formula for calculating the flow rate Q from Cv and ΔP, and , Storing an expression for calculating the opening degree of the main valve body 7 corresponding to the spring force of the coil spring 12 based on the pressure value detected by the pressure sensor 32, and calculating a flow rate from the relationship of the storage unit. Provide. The calculated flow rate value is displayed on the display unit 23 of the controller 22.
[0015]
When the high-pressure and high-speed steam flows down the main valve body 7 and the main valve port 8 and the lower surface of the piston 14 and the pressure applied to the piston 14 changes due to the flow of the fluid, this corresponds to an experiment in advance. The flow rate can be calculated with high accuracy by obtaining a correction coefficient and adding it to the flow rate equation: Q.
[0016]
The pressure reducing valve increases the set pressure as the adjusting screw 18 is tightened downward, and the pressure on the secondary side, that is, the outlet 3 side, can be maintained at a higher pressure. There is a specific correlation between the screwing amount of the adjusting screw 18 and the set pressure on the secondary side, and when the set pressure on the secondary side can be reliably grasped based on the screwing amount of the adjusting screw 18 from this relationship. Can also omit the pressure sensor 5 on the secondary side.
[0017]
【The invention's effect】
By detecting the pressure applied to the piston as a pressure responsive member, a valve displacement, that is, a valve opening detector is not required, and a pressure reducing valve capable of measuring the flow rate with a simple structure can be obtained. .
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional configuration diagram showing an embodiment of a pressure reducing valve with a flow rate measuring function of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body 2 Inlet 3 Outlet 5 Pressure sensor 7 Main valve body 14 Piston 15 Pilot valve body 16 Diaphragm 17 Coil spring 18 Adjustment screw 19 Motor 22 Controller 31 Pressure sensor 32 Pressure sensor 33 Space

Claims (1)

The pressure detection means detects the fluid pressure on the outlet side of the valve, that is, the secondary side, opens and closes the valve section via the pressure detection means and the pressure responsive member, and supplies or stops the primary high-pressure fluid to the secondary side. The flow rate of the pressure reducing valve can be calculated from the degree of opening of the pressure reducing valve that maintains the fluid pressure on the secondary side and the pressure on the primary and secondary sides. A valve part connected to the member is arranged, and the valve part is urged in the valve closing direction by an elastic member, and pressure detection means for detecting the pressure applied to the pressure responsive member is provided, and detection from the pressure detection means A calculation unit that converts the pressure into a load and calculates the opening degree of the valve unit from the canceling relationship with the elastic force of the elastic member is provided, and the calculation unit calculates from the opening degree of the valve unit and the primary side and secondary side pressure. A pressure reducing valve with a flow rate measuring function, characterized by calculating a flow rate flowing down the pressure reducing valve

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