JP4480552B2 - Flow control device and flow control method - Google Patents

Description

  The present invention relates to a system for pumping and supplying steam from a boiler device via a pipeline, and more specifically, a flow rate adjusting valve for adjusting the flow rate flowing through the pipeline when supplying steam. The present invention relates to a flow control device or a method therefor.

  FIG. 4 is a system diagram of a pipe line used in conventional steam supply. The steam 12 supplied by the system 100 is guided from the boiler 10 side to the customer side 13 via a pipe line (parent pipe) 11. A branch pipe 15 that branches to the intermediate pressure turbine 16 side at the branch point 11a is provided on the pipe (mother pipe) 11, and a flow rate is provided at a position closer to the customer 13 side than the branch point 11a. A control valve 14 is arranged.

In the system of the conventional steam supply plant as shown in FIG. 4, the flow control valve 14 that can be opened and closed is installed on the pipeline, and is set so as to be “always fully open” under normal conditions. At a specific time such as the time or the plant protection operation, it is necessary to protect the plant by performing an operation of converting the valve 14 from the open state to the closed state. However, since such a flow rate control valve 14 is always used in a fully open state during normal operation, the valve 14 is sticked (fixed or stuck), and the valve remains open and does not close. The situation may occur. When the flow control valve 14 has to be closed, the fact that the valve 14 does not shift from opening to closing means that the plant for supplying steam cannot be protected. .
In addition, as a patent document of the field | area relevant to this invention, there exist the following, for example.
JP 2002-4894 A

  As described above, in the conventional system for supplying steam, the flow rate control valve 14 provided in the pipe (flow path) may stick (stick) and cannot be closed. In order to achieve this, it is necessary to set a periodic frequency, open and close the flow control valve 14 installed on the pipe line, and perform an inspection to confirm that there is no stick (sticking). There was a problem.

  The present invention has been made in view of the above-mentioned problems, and prevents the flow rate control valve 14 from sticking (adhering) to be unable to open and close, eliminating the need for periodic valve opening and closing checks, It is another object of the present invention to provide a flow rate control apparatus and method that can contribute to system efficiency and cost reduction of a system related to steam supply.

(1) In a steam supply device for pumping and supplying steam from a boiler device via a pipe line provided with a flow control valve,
Means for measuring the flow rate through the flow control valve, the conduit for controlling such that the valve following the opening plus the margin the valve opening to the valve opening in accordance with the steam flow of the conduit And comprising
Based on the valve pressure loss of 0.0613 MPa in the flow rate adjusting valve, when the steam supply flow rate is 40 to 260 t / h, the valve opening degree is 15 to 100%, and the straight line (A) Means for obtaining each value indicating
The valve opening indicating the linear line (B) increased by giving a predetermined margin to the valve opening (%) of the line (A) is set to follow the valve with respect to the steam supply flow rate (t / h). Means to determine the opening (%);
Means for controlling the valve opening of the flow rate adjusting valve to operate based on the valve follow-up opening (%),
The valve follow-up opening degree (%) is configured by adding a margin of 15 to 25% to the valve opening degree (%), so that the steam supply amount is in a range of 40 to 200 t / h. The flow rate adjusting valve is set so as to always operate according to the line (B), and is set to 100% fully open above this range.

(2) In a steam supply device for supplying steam by pressure from a boiler device via a pipe line provided with a flow control valve,
Means for measuring the flow rate through the flow control valve, the conduit for controlling such that the valve following the opening plus the margin the valve opening to the valve opening in accordance with the steam flow of the conduit And comprising
Based on the valve pressure loss of 0.0613 MPa in the flow rate adjusting valve, when the steam supply flow rate is 40 to 260 t / h, the valve opening degree is 15 to 100%, and the straight line (A) Obtaining each value indicating
The valve opening degree indicating the linear line (B) increased by giving a predetermined margin to the valve opening degree (%) of the line (A) is opened to follow the valve with respect to the steam supply flow rate (t / h). The steps defined as degrees (%),
Controlling the valve opening degree of the flow rate adjustment valve based on the valve follow-up opening degree (%) with respect to the steam supply flow rate (t / h), and
The valve follow-up opening degree (%) is configured by adding a margin of 15 to 25% to the valve opening degree (%), so that the steam supply amount is in a range of 40 to 200 t / h. The flow rate adjusting valve is set so as to always operate according to the line (B), and is set to 100% fully open above this range.

  According to the flow control device or the method thereof according to the present invention, in the flow control valve provided on the flow path in the steam supply system, the valve follow-up opening having a value having a margin with respect to the actual flow is determined, and the flow control valve Based on this, it is configured to always follow-up control. As a result, the flow rate control valve on the flow path can always operate at an intermediate opening, and the flow rate control valve 14 is prevented from sticking (fixed) and cannot be opened and closed. No need for open / close inspection.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of a flow rate control device and a flow rate control method according to the present invention will be described with reference to FIGS.
FIG. 1 is a system diagram for supplying steam according to an embodiment of a flow control device of the present invention. The steam 22 supplied by this system 200 is guided from the boiler 20 side to the customer side 23 via a pipe (mother pipe) 21, and a conventional system diagram is provided on the pipe (mother pipe) 21. Similar to FIG. 4, a flow rate adjustment valve 24 is provided. In this system 200 according to the present invention, a flow meter (FX) 27 for measuring the flow rate in the pipe 21 ′ on the downstream side of the flow rate adjustment valve 24 and the measurement signal from the flow meter (FX) 27 are used. And a valve control unit 28 for controlling the opening / closing of the flow rate adjusting valve 24, and this valve control unit 28 outputs a command signal 28 ′ to control the opening / closing operation of the flow rate adjusting valve 24.

FIG. 2 is a diagram illustrating an example of characteristics of the flow rate adjusting (adjusting) valve 24 installed in the steam supply pipeline in the system 200 of FIG.
The upper table data in FIG. 2 is obtained by actually measuring the relationship between the steam supply flow rate (t / h) and the valve opening degree (%) based on a predetermined valve pressure loss (MPa) value in the flow rate adjusting valve 24. Is.
The line A in the lower graph of FIG. 2 is a line indicating the steam supply flow rate (t / h) -valve opening degree (%) based on the upper table data of FIG. Line B is a line indicating a valve follow-up opening degree (%), and the valve opening degree increased by giving a predetermined margin (here, 20%) to the valve opening degree (%) in the A line, This relationship is defined as a valve follow-up opening degree (%) with respect to the steam supply flow rate (t / h) and is shown in a graph. The A line and the B line are both substantially linear when the valve opening is less than 100%.

In the lower graph of FIG. 2, the A line is shown by plotting a1-a2-a3, and the B line is shown by plotting b1-b2-. With reference to the table data, these data are summarized as follows.
Steam supply flow rate (not including spray amount) Valve opening Valve following opening (+ 20%)
a1 35.2t / h 15% 35% (b1 point)
a2 100.1 t / h 44% 64% (b2 points)
a3 229.3t / h 100% 100% (b3 points)

In the lower graph of FIG. 2, each point will be described as follows.
a1 is a value when the steam supply flow rate is 40 t / h, and the valve opening degree at which the valve pressure loss becomes 0.0613 MPa is 15%, which is increased with a margin (20% here). In the valve follow-up opening degree (%), the valve follow-up opening degree is 35% (b1 point) when the steam supply flow rate is 40 t / h.
a2 is a value when the steam supply flow rate is 114 t / h, and the valve opening degree at which the valve pressure loss becomes 0.0613 MPa is 44%, which is increased with a margin (20% here). The valve follow-up opening degree (%) becomes the valve follow-up opening degree 64% (b2 point) when the steam supply flow rate is 114 t / h.
a3 is a value when the steam supply flow rate is 260 t / h, and the valve opening degree at which the valve pressure loss becomes 0.0613 MPa is 100%, which is increased with a margin (20% here). Since the valve opening cannot be increased to 100% or more at the valve follow-up opening (%), the valve follow-up opening remains at 100% when the steam supply flow rate is 260 t / h. The position will be heavy.

  Returning to the system 200 of FIG. 1, in the present invention, the steam supply flow rate (t / h) and the valve opening (%) are measured based on a predetermined valve pressure loss (MPa) value in the flow rate adjusting valve 24. The valve opening degree which is increased by giving a predetermined margin (here, 20%) to this valve opening degree (%) is determined as the valve following opening degree (%). Then, the valve opening degree of the flow rate adjusting valve 24 in the system 200 is set as a valve follow-up opening degree (%) with respect to the steam supply flow rate (t / h), and based on these, the valve control unit 24 sets the flow meter. The valve opening degree of the flow rate adjusting valve 24 corresponding to the steam supply flow rate (t / h) actually measured at 27 is controlled to be the valve follow-up opening degree (%). As a result of experiments, it has been confirmed that the valve follow-up opening (%) is preferably configured by adding a margin of 15 to 25% to the valve opening (%).

  As described above, in the present invention, by setting the valve follow-up opening degree (%) and operating the flow rate adjusting valve 24, the opening and closing of the flow rate adjusting valve 24 can always be flexibly controlled with an intermediate opening amount. Can prevent sticking. Further, as shown in FIG. 2, in setting the valve follow-up opening degree (%), the flow rate adjusting valve 24 is set to always operate in a range in which the steam supply amount is regularly used (40 to 200 t / h). Further, in the non-steady state (200 t / h or more) when the customer's steam usage is the largest (200 t / h or more), the flow rate adjustment valve 24 is set to be fully opened so that the pressure loss is reduced.

  FIG. 3 is a diagram showing an example of a system to which the present invention can be applied, and is a steam supply system diagram. The steam 32 supplied in the system 300 of FIG. 3 is guided from the boiler 30 side to the customer side 33 via the pipeline 31, and the flow rate adjustment valve 34 and the flow rate adjustment valve 34 are connected to the pipeline 31. A flow meter (FX) 35 for measuring the actual flow rate in the downstream pipe line 31 ', and a valve set to a value having a margin based on a measurement signal from the flow meter (FX) 35 The opening / closing operation of the flow rate adjusting valve 34 is controlled according to the follow-up opening degree (%). In the system 300 of FIG. 3, a check valve 36 and a steam supply source valve 37 are arranged in series on the upstream side of the flow rate adjustment valve 34 on the pipe 31, and downstream of the flow rate adjustment valve 34. On the side, a thermometer 38 is arranged in series.

The flow control valve 34 on the pipe line 31 of the system 300 in FIG. 3 is normally controlled to open and close the flow control valve 34 according to the valve follow-up opening degree (%) according to the present invention. It is also possible to control the opening / closing operation of the flow rate adjusting valve 34 with different settings.
Next, some examples will be given for controlling the operation of the valve at the specific time.
(1) When the supply steam temperature is “high” in the measurement by the thermometer 38, the flow rate control valve 34 is set to “closed” and the steam supply source valve 38 is set to “closed” after a certain period of time.
(2) When the steam supply capacity exceeds the steam supply capacity in the flow meter 35, the flow control valve 34 performs a “restriction” operation below the steam supply capacity.
(3) During the steam shut-off operation, the flow control valve 34 is set to “fully closed”.

  INDUSTRIAL APPLICABILITY The flow rate control device and the flow rate control method according to the present invention can be widely applied as a flow rate control system in which a flow rate adjusting valve provided on a pipe does not stick in a system for supplying steam. The above availability is extremely large.

1 is a system diagram showing an embodiment of a flow control device or method according to the present invention. It is a data figure for demonstrating one Embodiment of the flow control apparatus or method by this invention. It is a systematic diagram which shows another embodiment of the flow control apparatus or method by this invention. It is a systematic diagram for demonstrating the flow control of the conventional steam supply.

Explanation of symbols

200 system 20 boiler 21, 21 'pipeline (mother pipe)
22, 22 'Steam flow 23 Customer 24 Flow control valve 25 Reheat steam pipe 26 Turbine 27 Flow meter (FX)
28 Valve control unit
A Line indicating valve opening (%)
B Line indicating valve follow-up opening (%)

Claims (2)

In a steam supply device for supplying steam by pressure via a pipe line provided with a flow control valve from a boiler device,
Means for measuring the flow rate through the flow control valve, the conduit for controlling such that the valve following the opening plus the margin the valve opening to the valve opening in accordance with the steam flow of the conduit And comprising
Based on the valve pressure loss of 0.0613 MPa in the flow rate adjusting valve, when the steam supply flow rate is 40 to 260 t / h, the valve opening degree is 15 to 100%, and the straight line (A) Means for obtaining each value indicating
The valve opening indicating the linear line (B) increased by giving a predetermined margin to the valve opening (%) of the line (A) is set to follow the valve with respect to the steam supply flow rate (t / h). Means to determine the opening (%);
Means for controlling the valve opening of the flow rate adjusting valve to operate based on the valve follow-up opening (%),
The valve follow-up opening degree (%) is configured by adding a margin of 15 to 25% to the valve opening degree (%), so that the steam supply amount is in a range of 40 to 200 t / h. The flow rate control device is set so that the flow rate adjusting valve always operates according to the line (B), and is set to be 100% fully open above this range. In a steam supply device for supplying steam by pressure via a pipe line provided with a flow control valve from a boiler device,
Means for measuring the flow rate through the flow control valve, the conduit for controlling such that the valve following the opening plus the margin the valve opening to the valve opening in accordance with the steam flow of the conduit And comprising
Based on the valve pressure loss of 0.0613 MPa in the flow rate adjusting valve, when the steam supply flow rate is 40 to 260 t / h, the valve opening degree is 15 to 100%, and the straight line (A) Obtaining each value indicating
A valve opening degree indicating a linear line (B) increased by giving a predetermined margin to the valve opening degree (%) of the previous line (A) is a valve for the steam supply flow rate (t / h). A step determined as a follow-up opening (%);
And controlling the valve opening of the flow rate adjusting valve to operate based on the valve follow-up opening (%),
The valve follow-up opening degree (%) is configured by adding a margin of 15 to 25% to the valve opening degree (%), so that the steam supply amount is in a range of 40 to 200 t / h. The flow rate control method is characterized in that the flow rate adjusting valve is set so as to always operate according to the line (B), and is set to 100% in a fully open state above this range.

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