JPH04220703A - Valve device - Google Patents

Abstract

PURPOSE:To reduce the size and cost by providing the valve device with a flow rate limiting function by combining a flow rate limiting mechanism with the valve device which has a pressure regulating function. CONSTITUTION:The flow rate limiting mechanism 3 which has a control flow rate 16 linking a driving part 2 receiving pressure from a secondary flow passage 6 with a primary flow passage 5, a throttle valve 17 provided the control flow passage, a control part 18 controlling the opening extent of said throttle valve 17 corresponding to a signal regarding a flow rate, and a driving part 19 is combined with a valve main body 1 which performs pressure regulating operation associatively with said driving part 2 and the flow rate of said valve main body 1 is limited below a permissible value.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to a valve device installed in a piping system, etc. for distributing heat energy from a specific supply source to a large number of users, such as a district heating and cooling system, and is used for pressure regulation and flow rate restriction. This invention relates to a valve device that has both functions.

0002

2. Description of the Related Art In a district heating and cooling system, the usage patterns of individual users generally vary, and the demand flow rate of a heat medium also fluctuates irregularly. Therefore, it is difficult to deal with this problem only through centralized control at the supply source, and usually there is a means to automatically adjust the heat medium pressure to the desired level for each consumer, and a means to adjust the demand flow rate to the contract value (hereinafter referred to as the allowable value). There needs to be a way to automatically limit the amount so that it is not exceeded. For this purpose, conventionally, as illustrated in FIG.
and a flow rate limiting valve c (consisting of an orifice valve d and a differential pressure valve e).

0003

[Problems to be Solved by the Invention] In the conventional example, as mentioned above, in addition to the pressure regulating valve b, a flow rate limiting valve c consisting of two valves d and e is required, so the device is large and requires a large space. , and the flow rate limiting valve c must be set for each consumer so that the demand flow rate does not exceed a permissible value, making adjustment complicated, which is disadvantageous in terms of cost.

The present invention was made to solve the above-mentioned problems, and has a simple structure, small size, low cost, and easy adjustment while having both pressure adjustment and flow rate restriction functions. Therefore, it is an object of the present invention to provide a valve device particularly suitable for district heating and cooling systems.

[0005]

[Means for Solving the Problems] The present invention provides a valve device which is provided in the piping and has a driving part that responds to the pressure of the fluid flowing through the piping, in which the driving part responds to the flow rate of the fluid. The device is characterized in that it is equipped with a flow rate restriction mechanism that can control the flow rate.

[0006]

[Operation] In the above configuration, when the demand flow rate is less than the allowable value, the flow rate restriction mechanism does not operate to limit the flow rate, and the drive unit controls the valve opening according to the fluid pressure. This provides the usual pressure regulating effect. Further, when the demand flow rate exceeds the allowable value, the drive section is controlled via the flow rate restriction mechanism to throttle the valve opening and limit the flow rate to below the allowable value.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings.

In FIG. 1, the valve device integrally includes a valve body 1, a drive section 2, and a flow rate restriction mechanism 3 that cooperate with each other.

A primary flow path 5 and a secondary flow path 6 are formed in the valve box 4 of the valve body 1, and the opening degree of the valve hole 7 provided between these flow paths 5 and 6 is controlled. The valve body 8 to be controlled is a valve shaft 9
It is connected to the drive section 2 via.

The drive section 2 includes a case 10 connected to the valve box 4. This case 10 is formed with a sealed first chamber 11 and a second chamber 12 that communicates with the outside air, and is interposed between these two chambers 11 and 12, with a central portion connected to the valve shaft 9. The peripheral edge of the diaphragm 13 is supported. Further, a spring 14 is interposed between the case 10 and the valve shaft 9 to bias the valve body 8 in the opening direction, and the first chamber 11 is It communicates with the secondary flow path 6 mentioned above. As will be described later, the valve body 1 and the drive section 2 can cooperate with each other to perform a pressure regulating action, so that both constitute a pressure regulating valve.

The flow rate restriction mechanism 3 includes an upstream control flow path 16 that communicates the first chamber 11 of the drive section 2 with the primary flow path 5 of the valve body 1, and a throttle valve 17 provided in the control flow path 16. ,
The control unit 18 includes a control unit 18 into which a signal related to the flow rate is input, and a drive unit (for example, an electric motor) 19 that controls the opening of the throttle valve 17 in cooperation with the control unit 18 .

When the above embodiment is applied to a district heating and cooling system, the valve body 1 is connected to an individual pipe 20 through which a heat medium flows, as illustrated in FIG. , an on-off valve 22, and a strainer 23, and on the downstream side, an on-off valve 22, a pressure gauge 21, and a measuring device 24 are provided, respectively. Furthermore, a maintenance bypass pipe 25 equipped with an on-off valve 22 is connected between intermediate points of the pressure gauge 21 and on-off valve 22 on the upstream and downstream sides. A signal sent from the meter 24 in relation to the flow rate of the heat medium is guided to the control section 18 of the flow rate restriction mechanism 3.

Next, the operation of the above embodiment will be explained in the case where the valve body 1 is connected to the individual pipe 20.

As shown in FIG. 3 illustrating the relationship between the elapsed time (T) and the demand flow rate (Q), when the demand flow rate flowing through the individual pipes 20 is below the allowable value Q0 (area I), the above-mentioned Even if the signal from the meter 24 is input to the control unit 18, the drive unit 19 does not operate to limit the flow rate.
Since the throttle valve 17 remains closed, the upstream control flow path 16 of the drive section 2 is closed. Therefore, the downstream pressure is introduced from the secondary flow path 6 to the first chamber 11 of the drive unit 2, and urges the diaphragm 13 in the closing direction. The valve opening degree is automatically adjusted so that this biasing force in the closing direction and the biasing force in the opening direction by the spring 14 are balanced through the valve shaft 9, so that the downstream pressure is maintained at a preset desired level. ing. That is, a normal pressure adjustment effect is performed by automatically controlling the valve opening according to the fluid pressure.

In this state, when the flow rate increases and the demand flow rate exceeds the allowable value Q0 (region II), the drive unit 19 operates in response to a signal input from the meter 24 to the control unit 18. As a result, the throttle valve 17 is opened. Therefore, the upstream pressure is introduced into the first chamber 11 of the drive section 2 from the primary flow path 5, and urges the diaphragm 13 in the closing direction. This biasing force in the closing direction moves the valve body 8 in the closing direction against the biasing force in the opening direction by the spring 14, thereby increasing the flow rate to the allowable value Q0 (or its vicinity).
(region III). In other words, the valve body 1 performs the flow rate limiting action in cooperation with the drive unit 2 and the flow rate limiting mechanism 3.

[0016] If the demand flow rate further decreases below the allowable value Q0 (or its vicinity) (region IV), the throttle valve 1
7 is closed, and the operating mode is transferred from the flow restriction region to the pressure regulation region.

As described above, by providing the flow rate restriction mechanism 3, the valve body 1 and the drive unit 2 can perform both pressure regulation and flow rate restriction, so that the conventional method requiring three valves connected in series can be avoided. Compared to the example, the structure is simpler and smaller, requiring less space, and not only is the cost lower, but the pressure loss is also smaller. Also,
Since the flow rate limiting mechanism 3 is controlled according to an input signal related to the flow rate, initial adjustment is easy and it is highly reliable.

It should be noted that the present invention is not limited to the above-mentioned embodiments. For example, instead of the drive section 2, other suitable drive means (such as a piston-type drive section or a pilot valve as shown in FIG. 4) may be used. It is also possible to provide a In addition, various modifications and applications are possible within the scope of the gist of the present invention.

[0019]

Effects of the Invention As described in detail above, according to the present invention, the structure is simple, compact, and low cost while having both the functions of pressure regulation and flow rate restriction, and furthermore, adjustment is easy, and especially for district heating and cooling. A suitable valve arrangement can be provided for the system.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a valve device according to an embodiment of the present invention.

FIG. 2 is a system diagram illustrating a case where the embodiment is applied to a district heating and cooling system.

FIG. 3 is a diagram for explaining the operation of the embodiment.

FIG. 4 is an explanatory diagram showing a modification of the same embodiment.

FIG. 5 is a system diagram showing a conventional example.

[Explanation of symbols]

1... Valve body, 2, 19... Drive unit, 3... Flow rate restriction mechanism, 1
5, 16... Control flow path, 17... Throttle valve, 18... Control section, 2
0...Individual piping, 24...Measuring instrument.

Claims (1)

[Claims] 1. A valve device provided in the piping and having a driving part that responds to the pressure of the fluid flowing through the piping, comprising a flow rate restriction mechanism that can control the driving part in relation to the flow rate of the fluid. A valve device comprising: