JP2020201145A - Flow rate measurement device - Google Patents

Abstract

To provide a flow rate measurement device that can easily and reliably perform air bleed of a connecting pipe of an outlet-side differential pressure type flowmeter for measuring the flow rate of coolant flowing in an outlet-side pipe of cooling equipment located in an environment where an inlet-side pipe inside installed at the inlet side of a cooling object is under a positive pressure while the outlet-side pipe inside is under a negative pressure.SOLUTION: A flow rate measurement device 1 measures the flow rate of coolant flowing in an outlet-side pipe 13 of cooling equipment 10 using an outlet-side differential pressure type flowmeter 3. In the cooling equipment 10, the inlet-side pipe 12 inside is under a positive pressure environment while the outlet-side pipe 13 inside is under a negative pressure environment. In the flow rate measurement device 1, the inlet-side pipe 12 and connecting pipes 33 and 34 of the outlet-side differential pressure type flowmeter 3 are connected by a bypass pipe 4 that pumps the coolant W flowing in the inlet-side pipe 12 under the positive pressure environment directly to the connecting pipes 33 and 34 during air bleed of the connecting pipes 33 and 34 of the outlet-side differential pressure type flowmeter 3.SELECTED DRAWING: Figure 2

Description

According to the present invention, in a cooling facility in which the inside of the inlet pipe installed on the inlet side of the object to be cooled is in a positive pressure environment and the inside of the outlet pipe is in a negative pressure environment, the flow rate of cooling water flowing in the outlet pipe The present invention relates to a flow rate measuring device capable of reliably bleeding air from a pressure guiding pipe of a discharge side differential pressure type flow meter.

For example, in a factory such as a steel mill, the cooling water flowing in the inlet pipe installed on the inlet side of the object to be cooled circulates in the object to be cooled to cool the object to be cooled and cool the object to be cooled. A cooling facility may be provided in which the cooling water flows through the outlet pipe installed on the outlet side of the object to be cooled and is discharged. This is to prevent the object to be cooled from becoming hot.
In such a cooling facility, in order to verify whether the cooling object is properly cooled, the flow rate of the cooling water flowing in the outlet piping installed on the outlet side of the cooling object is the outlet differential pressure flow rate. It may be measured by a meter.

Here, conventionally, as a differential pressure type flowmeter of this kind, for example, those shown in Patent Documents 1 to 3 are known.
In the differential pressure type flow rate measuring device shown in Patent Document 1, a first pressure portion and a second pressure portion for detecting the fluid pressure of the fluid to be measured are arranged via a pressure loss portion. Then, the opening / closing operation of the connection flow path portion that connects the first pressure detection unit and the second pressure detection unit with a single flow path, the on-off valve portion having the poppet valve body, and the on-off valve portion is controlled. It has a calculation unit.

Further, the flow rate measuring device shown in Patent Document 2 is a flow rate measuring device in which a differential pressure type flow rate sensor unit is connected to the main flow path via a primary side pressure flow path and a secondary side pressure flow path, and is a differential pressure type flow rate sensor. The unit is provided with a calculation unit that divides the chamber unit into a first chamber and a second chamber by a first diaphragm and a second diaphragm, and converts a signal from a load detection sensor arranged between the diaphragms into a flow rate signal. .. The primary pressure flow path connects the main flow path and the first chamber, and the secondary side pressure flow path connects the main flow path and the second chamber, and a pressure loss portion that generates a differential pressure between the chambers. An on-off valve portion is provided in the main flow path while each pressure flow path is connected.

Further, in the flow rate measuring device shown in Patent Document 3, a differential pressure type flow rate sensor unit is connected to the main flow path via the primary side pressure flow path and the secondary side pressure flow path. The differential pressure type flow rate sensor unit includes an intermediate partition portion having an intermediate diaphragm that partitions the first chamber and the second chamber between the first diaphragm and the second diaphragm arranged to face each other at both ends of the shaft portion. There is. Further, this flow rate measuring device includes a calculation unit that converts a signal from a load detection sensor that detects the back pressure of the first diaphragm into a flow rate signal, a pressure loss unit that generates a differential pressure between each chamber, and each pressure flow. An on-off valve portion is provided in the main flow path while the roads are connected.

JP-A-2010-78365 JP-A-2010-44011 JP-A-2010-44012

By the way, in the above-mentioned cooling equipment, when measuring the flow rate of the cooling water flowing in the outlet pipe installed on the outlet side of the object to be cooled by the outlet differential pressure type flow meter, first of all, in the outlet pipe. It is necessary to bleed the air from the pressure guiding pipe in the outlet side differential pressure type flow meter that guides the pressure of the cooling water to the differential pressure transmitter.
On the other hand, in such a cooling facility, depending on the installation status of the facility, the inside of the inlet piping installed on the inlet side of the object to be cooled is placed in a positive pressure environment, and the outlet installed on the outlet side of the object to be cooled. The inside of the side pipe may be placed in a negative pressure environment. For example, the outlet pipe is installed at a high place with respect to the inlet pipe, and the air in the outlet pipe is pulled by the weight of the cooling water discharged from the outlet pipe toward the discharge tank, so that the inside of the outlet pipe is This is the case when the pressure becomes negative.

In such a cooling facility where the inside of the outlet pipe is in a negative pressure environment, if the air is bleeded from the pressure guide pipe of the outlet side differential pressure type flow meter, the air is sucked into the pressure guide pipe when the air bleeding valve is opened. Therefore, bleeding air from the pressure guiding pipe is a very difficult task. For this reason, in general, in a cooling facility in which the inside of the outlet pipe is in a negative pressure environment, when air is bleeded from the pressure guiding pipe of the outlet differential pressure type flow meter, a fluid separately prepared from the air bleeding valve is used by negative pressure. It is sucked to fill the pressure guiding tube with a fluid, thereby bleeding air.
However, this method has a problem that if the difference pressure between the atmospheric pressure and the inside of the pressure guiding tube is not sufficient, the fluid cannot be sucked properly and the fluid does not spread over the entire inside of the pressure guiding tube. In addition, the atmosphere may be sucked while the fluid is being sucked into the pressure guiding tube.

On the other hand, in the conventional differential pressure type flow rate measuring device shown in Patent Document 1, the flow rate measuring device shown in Patent Document 2, and the flow rate measuring device shown in Patent Document 3, the inside of the inlet pipe is in a positive pressure environment. There is no disclosure about bleeding air from the pressure guiding tube of the output side differential pressure type flow meter in a cooling facility where the inside of the side piping is in a negative pressure environment.
Therefore, the present invention has been made to solve this conventional problem, and an object of the present invention is that the inside of the inlet pipe installed on the inlet side of the object to be cooled is in a positive pressure environment and the inside of the outlet pipe. Provides a flow rate measuring device that can easily and surely bleed the air in the pressure guiding tube of the output side differential pressure type flow meter that measures the flow rate of the cooling water flowing in the output side piping in the cooling equipment in a negative pressure environment. To do.

In order to solve the above problems, in the flow rate measuring device according to one aspect of the present invention, the cooling water flowing in the inlet pipe installed on the inlet side of the object to be cooled circulates in the object to be cooled to cool the object. Cooling water that cools the object and cools the cooling object flows through the outlet pipe of the cooling facility that is discharged by flowing through the outlet pipe installed on the outlet side of the cooling object. In a flow rate measuring device that measures the flow rate with an output side differential pressure type flow meter, in the cooling facility, the inside of the inlet side pipe is in a positive pressure environment and the inside of the outlet side pipe is in a negative pressure environment. When the inlet pipe and the pressure guiding pipe of the outlet side differential pressure type flow meter are bleeding air from the pressure guiding pipe of the outlet side differential pressure type flow meter, the cooling water flowing in the inlet pipe under a positive pressure environment is supplied. The gist is that it is connected to the pressure guiding pipe by a bypass pipe that directly pumps.

According to the flow rate measuring device according to the present invention, in a cooling facility in which the inside of the inlet pipe installed on the inlet side of the object to be cooled is in a positive pressure environment and the inside of the outlet pipe is in a negative pressure environment, the outlet pipe It is possible to provide a flow rate measuring device capable of easily and surely bleeding air from a pressure guiding tube of a discharge side differential pressure type flow meter that measures the flow rate of cooling water flowing inside.

It is a figure which shows schematic the whole structure of the flow rate measuring apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the main part of the flow rate measuring apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the structure of the main part of the flow rate measuring apparatus which concerns on 2nd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments shown below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention describes the material, shape, structure, arrangement, etc. of the components. It is not specified in the following embodiments. The drawings are schematic. Therefore, it should be noted that the relationship, ratio, etc. between the thickness and the plane dimension are different from the actual ones, and there are parts where the relationship and ratio of the dimensions are different between the drawings.

(First Embodiment)
FIG. 1 shows an overall schematic configuration of the flow rate measuring device according to the first embodiment of the present invention, in which the flow rate measuring device 1 shows the flow rate of the cooling water W flowing in the inlet pipe 12 of the cooling facility 10. Is measured by the inlet side differential pressure type flow meter 2, and the flow rate of the cooling water W flowing in the outlet side pipe 13 of the cooling facility 10 is measured by the outlet side differential pressure type flow meter 3.
Here, the cooling facility 10 is, for example, a facility installed in a steel mill, and the cooling water W flowing in the inlet pipe 12 installed on the inlet side of the cooling object 11 circulates in the cooling object 11. The cooling object 11 is cooled, and the cooling water W that has cooled the cooling object 11 flows through the outlet pipe 13 installed on the outlet side of the cooling object 11 and is discharged to the drain tank 14. In the cooling facility 10, the inside of the inlet side pipe 12 is in a positive pressure environment, and the inside of the outlet side pipe 13 is in a negative pressure environment. The highest position of the outlet pipe 13 is installed higher than the highest position of the inlet pipe 12, and the stroke from the highest position of the outlet pipe 13 to the drainage tank is long, and the pipe is discharged from the outlet pipe toward the discharge tank. The air in the outlet pipe is pulled by the weight of the cooling water, and the pressure inside the outlet pipe becomes negative.

The configuration of the main part of the flow rate measuring device 1 according to the first embodiment is shown in FIG. 2, and the inlet differential pressure type flow meter 2 for measuring the flow rate of the cooling water W flowing in the inlet pipe 12 is It is provided with an orifice plate 21 installed so as to cross the inlet pipe 12. The orifice plate 21 is formed with an orifice 21a having an outer diameter smaller than the inner diameter of the inlet pipe 12, and this orifice 21a constitutes a pressure drop source. Further, the inlet differential pressure type flow meter 2 includes a differential pressure transmitter 22 that transmits a differential pressure signal in the inlet pipe 12 before and after the orifice plate 21 to an arithmetic unit (not shown). The arithmetic unit calculates the flow rate of the cooling water W flowing in the inlet pipe 12 based on the differential pressure signal from the differential pressure transmitter 22.

Then, the inlet differential pressure type flowmeter 2 takes out the pressure in the inlet pipe 12 on the front side (left side and upstream side in FIG. 2) of the orifice plate 21 and guides the pressure to the differential pressure transmitter 22 on the front side pressure guiding tube. 23 and a rear pressure guiding tube 24 as a pressure guiding tube for taking out the pressure in the inlet pipe 12 on the rear side (right side, downstream side in FIG. 2) of the orifice plate 21 and guiding it to the differential pressure transmitter 22 are provided. ..
The front pressure guiding pipe 23 branches from the front first pressure guiding pipe 23a for taking out the pressure in the inlet pipe 12 on the front side of the orifice plate 21 and the front first pressure guiding pipe 23a, and applies the pressure to the differential pressure transmitter 22. It is provided with a front second pressure guiding pipe 23b for guiding. A main valve 25a is installed in the front side first pressure guiding pipe 23a, and the front side second pressure guiding pipe 23b branches from the downstream side of the installation position of the main valve 25a of the front side first pressure guiding pipe 23a. A stop valve 26a is installed in the front second pressure guiding pipe 23b. Further, an air bleeding valve 28a is installed at the downstream end of the front first pressure guiding pipe 23a.

Further, the rear pressure guiding pipe 24 branches from the rear first pressure guiding pipe 24a for taking out the pressure in the inlet pipe 12 on the rear side of the orifice plate 21 and the pressure applied from the rear first pressure guiding pipe 24a. It is provided with a second pressure guiding pipe 24b on the rear side leading to the differential pressure transmitter 22. A main valve 25b is installed in the rear first pressure guiding pipe 24a, and the rear second pressure guiding pipe 24b branches from the downstream side of the installation position of the main valve 25b of the rear first pressure guiding pipe 24a. A stop valve 26b is installed in the second pressure guiding pipe 24b on the rear side. Further, an air bleeding valve 28b is installed at the downstream end of the rear first pressure guiding pipe 24a.

Further, it branches from a position rearward from the installation position of the stop valve 26a of the front side second pressure guiding pipe 23b and is connected to a position on the front side of the installation position of the stop valve 26b of the rear side second pressure guiding pipe 24b. A branch pipe 27a is provided, and a pressure equalizing valve 27 is installed in the branch pipe 27a.
Further, the outlet side differential pressure type flow meter 3 for measuring the flow rate of the cooling water W flowing in the outlet side pipe 13 includes an orifice plate 31 installed so as to cross the outlet side pipe 13. The orifice plate 31 is formed with an orifice 31a having an outer diameter smaller than the inner diameter of the outlet pipe 13. Further, the output side differential pressure type flow meter 3 includes a differential pressure transmitter 32 that transmits a differential pressure signal in the output side pipes 13 before and after the orifice plate 31 to an arithmetic unit (not shown). The arithmetic unit calculates the flow rate of the cooling water W flowing in the outlet pipe 13 based on the differential pressure signal from the differential pressure transmitter 32.

Then, the outlet side differential pressure type flowmeter 3 takes out the pressure in the outlet side pipe 13 on the front side (left side in FIG. 2) of the orifice plate 31 and guides the pressure to the differential pressure transmitter 32 with the front side pressure guiding pipe 33 as a pressure guiding pipe. A rear pressure guiding pipe 34 is provided as a pressure guiding pipe that takes out the pressure in the outlet pipe 13 on the rear side (right side in FIG. 2) of the orifice plate 31 and guides it to the differential pressure transmitter 32.
The front pressure guiding pipe 33 branches from the front first pressure guiding pipe 33a for taking out the pressure in the outlet pipe 13 on the front side of the orifice plate 31 and the pressure applied from the front first pressure guiding pipe 33a to the differential pressure transmitter 22. It is provided with a front second pressure guiding pipe 33b for guiding. A main valve 35a is installed in the front side first pressure guiding pipe 33a, and the front side second pressure guiding pipe 33b branches from the downstream side of the installation position of the main valve 35a of the front side first pressure guiding pipe 33a. A stop valve 36a is installed in the front second pressure guiding pipe 33b. Further, an air bleeding valve 38a is installed at the downstream end of the front first pressure guiding pipe 33a.

Further, the rear pressure guiding pipe 34 branches from the rear first pressure guiding pipe 34a for taking out the pressure in the outlet pipe 13 on the rear side of the orifice plate 31 and the pressure applied from the rear first pressure guiding pipe 34a. It is provided with a rear second pressure guiding pipe 34b that leads to the differential pressure transmitter 32. A main valve 35b is installed in the rear first pressure guiding pipe 34a, and the rear second pressure guiding pipe 34b branches from the downstream side of the installation position of the main valve 35b of the rear first pressure guiding pipe 34a. A stop valve 36b is installed in the rear second pressure guiding pipe 34b. Further, an air bleeding valve 38b is installed at the downstream end of the rear first pressure guiding pipe 34a.

Further, it branches from a position rearward from the installation position of the stop valve 36a of the front side second pressure guiding pipe 33b and is connected to a position on the front side of the installation position of the stop valve 36b of the rear side second pressure guiding pipe 34b. A branch pipe 37a is provided, and a pressure equalizing valve 37 is installed in the branch pipe 37a.
Then, when measuring the flow rate of the cooling water W flowing in the inlet pipe 12 by the inlet differential pressure type flow meter 2, air is bleeded in the front side pressure guiding pipe 23 and the rear side pressure guiding pipe 24, and the outlet side differential pressure type flow meter is used. When measuring the flow rate of the cooling water W flowing in the outlet side pipe 13 by 3, it is necessary to bleed the air in the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34. Here, since the inside of the inlet side pipe 12 is in a positive pressure environment, air bleeding in the front side pressure guiding pipe 23 and the rear side pressure guiding pipe 24 of the inlet side differential pressure type flow meter 2 does not matter. On the other hand, since the inside of the discharge side pipe 13 is in a negative pressure environment, air bleeding in the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the discharge side differential pressure type flow meter 3 becomes a problem.

Explaining this problem, when bleeding air in the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3, the main valve 35a and the main valve 35b are opened, and the air bleeding valve 38a and the air bleeding valve 38b are opened. Open and bleed the air in the front side first pressure guiding pipe 33a and the rear side first pressure guiding pipe 34a. Further, with the main valve 35a and the main valve 35b closed, the stop valve 36a, the stop valve 36b and the drain valve (not shown) are opened, and the air bleeding valve 38a and the air bleeding valve 38b are opened to open the front second pressure guiding pipe 33b and The air in the rear second pressure guiding pipe 34b is evacuated. At this time, if the inside of the outlet side pipe 13 is in a negative pressure environment, when the air bleeding valve 38a and the air bleeding valve 38b are opened, the inside of the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34, particularly the front side first pressure guiding Atmosphere is sucked into the pipe 33a and the rear first pressure guiding pipe 34a. Therefore, bleeding air in the front pressure guiding tube 33 and the rear pressure guiding tube 34 is a very difficult task.

Therefore, in the flow rate measuring device 1 according to the present embodiment, the inlet side pipe 12 and the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3 are connected by a bypass pipe 4. Then, when the air is bleeded from the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3, the cooling water W flowing in the inlet side pipe 12 under a positive pressure environment is passed through the bypass pipe 4 to the front side. The pressure is sent directly to the pressure guiding pipe 33 and the rear pressure guiding pipe 34.

Specifically explaining this, as the bypass pipe 4, the front side first pressure guiding pipe 23a of the front side pressure guiding pipe 23 of the inlet side differential pressure type flowmeter 2 is used, and the bypass pipe 4 is connected to the front side first pressure guiding pipe 23a. The first bypass pipe 40 is connected to the air bleeding valve 28a, and the air bleeding valve 45 is installed at the downstream end of the first bypass pipe 40. Further, the first bypass pipe 40 is connected to the second bypass pipe 41 in which the air bleeding valve 44 is installed. Further, the third bypass pipe 42 is branched from the second bypass pipe 41, and the air bleeding valve 38a connected to the front first pressure guiding pipe 33a of the front side pressure guiding pipe 33 of the outlet side differential pressure type flow meter 3 is connected to the first. 3 Connect the bypass pipe 42. Further, a fourth bypass pipe 43 is extended from the end of the second bypass pipe 41 and is connected to the rear first pressure guiding pipe 34a of the rear pressure guiding pipe 34 of the output side differential pressure type flow meter 3. A fourth bypass pipe 43 is connected to the air bleeding valve 38b. Therefore, the bypass pipe 4 is composed of the front side first pressure guiding pipe 23a, the first bypass pipe 40, the second bypass pipe 41, the third bypass pipe 42, and the fourth bypass pipe 43.

Then, when bleeding air from the front pressure guiding pipe 33 and the rear pressure guiding pipe 34 of the outlet side differential pressure type flowmeter 3, the main valve 25a and the air bleeding valve of the inlet side differential pressure type flowmeter 2 with the air bleeding valve 45 closed. 28a, the air bleeding valve 44, the air bleeding valve 38a of the outlet side differential pressure type flow meter 3, the air bleeding valve 38b, the main valve 35a, and the main valve 35b are opened. As a result, as shown by the arrow in FIG. 2, the cooling water W flowing in the inlet side pipe 12 under a positive pressure environment is shown by the front side first pressure guiding pipe 23a and the first bypass pipe 40 of the inlet side differential pressure type flow meter 2. , The second bypass pipe 41 and the third bypass pipe 42 are pumped to the front first pressure guiding pipe 33a of the front pressure guiding pipe 33. At the same time, the cooling water W is led to the rear side via the front side first pressure guiding pipe 23a, the first bypass pipe 40, the second bypass pipe 41, and the fourth bypass pipe 43 of the inlet side differential pressure type flow meter 2. It is pumped to the first pressure guiding pipe 34a on the rear side of the pressure pipe 34. As a result, the inside of the front side first pressure guiding pipe 33a and the inside of the rear side first pressure guiding pipe 34a of the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3 are completely filled with the cooling water W. Then, the cooling water W containing air is discharged from the outlet pipe 13 to the drainage tank 14. As a result, the air is evacuated from the front side first pressure guiding pipe 33a and the rear side first pressure guiding pipe 34a of the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3 from the outside. You can do it without doing it.

Further, air bleeding of the front side second pressure guiding pipe 33b and the rear side second pressure guiding pipe 34b of the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3 will be described. At this time, with the main valve 35a and the main valve 35b of the air bleeding valve 45 and the outlet side differential pressure type flowmeter 3 closed, the main valve 25a, the air bleeding valve 28a, and the air bleeding of the inlet side differential pressure type flowmeter 2. Open the valve 44, the air bleeding valve 38a, the air bleeding valve 38b, the stop valve 36a, the stop valve 36b, and the drain valve (not shown) of the discharge side differential pressure type flow meter 3. As a result, the cooling water W flowing in the inlet side pipe 12 under a positive pressure environment is passed through the front side first pressure guiding pipe 23a, the first bypass pipe 40, the second bypass pipe 41, and the first side differential pressure type flow meter 2. 3 The pressure is sent to the front second pressure guiding pipe 33b of the front pressure guiding pipe 33 via the bypass pipe 42. At the same time, the cooling water W is led to the rear side via the front side first pressure guiding pipe 23a, the first bypass pipe 40, the second bypass pipe 41, and the fourth bypass pipe 43 of the inlet side differential pressure type flow meter 2. It is pumped to the second pressure guiding pipe 34b on the rear side of the pressure pipe 34. As a result, the inside of the front side second pressure guiding pipe 33b and the inside of the rear side second pressure guiding pipe 34b of the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3 are completely filled with the cooling water W. Then, the cooling water W containing air is discharged from the drain valve. As a result, the air is evacuated from the front side second pressure guiding pipe 33b and the rear side second pressure guiding pipe 34b of the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3, and the atmosphere is sucked from the outside. You can do it without doing it.

When bleeding air from the front side first pressure guiding pipe 23a and the rear side first pressure guiding pipe 24a of the inlet side differential pressure type flow meter 2, the air bleeding valve 45, the air bleeding valve 28a, the air bleeding valve 28b, and the main valve 25a are used. And open the main valve 25b. As a result, the cooling water W flowing in the inlet side pipe 12 under a positive pressure environment flows through the front side first pressure guiding pipe 23a and the rear side first pressure guiding pipe 24a of the inlet side differential pressure type flow meter 2 to release air. The included cooling water W is discharged from the air bleeding valve 45 and the air bleeding valve 28b, and the air is bleeded from the front side first pressure guiding pipe 23a and the rear side first pressure guiding pipe 24a.
Further, when bleeding air from the front side second pressure guiding pipe 23b and the rear side second pressure guiding pipe 24b of the inlet side differential pressure type flow meter 2, the air bleeding valve 45, with the main valve 25a and the main valve 25b closed, Open the air bleeding valve 28a, the air bleeding valve 28b, the stop valve 26a, the stop valve 26b, and the drain valve (not shown). As a result, the air in the front side second pressure guiding pipe 23b and the rear side second pressure guiding pipe 24b is discharged from the drain valve.

Then, when measuring the flow rate of the cooling water W flowing in the inlet pipe 12 with the inlet differential pressure type flow meter 2, the main valve 25a, the main valve 25b, the stop valve 26a, and the stop valve 26b are opened, and the air bleeding valve is opened. 28a, the air bleeding valve 28b, the air bleeding valve 44, and the air bleeding valve 45 are closed, and the pressure equalizing valve 27 is closed.
Further, when measuring the flow rate of the cooling water W flowing in the outlet side pipe 13 with the outlet side differential pressure type flow meter 3, the main valve 35a, the main valve 35b, the stop valve 36a, and the stop valve 36b are opened to open the air bleeding valve. This is performed with the pressure equalizing valve 37 closed while the 38a and the air bleeding valve 38b are closed.

As described above, according to the flow rate measuring device 1 according to the first embodiment, in the cooling facility 10, the inside of the inlet side pipe 12 is in a positive pressure environment and the inside of the outlet side pipe 13 is in a negative pressure environment. In, the inlet side pipe 12 and the front side pressure guide pipe 33 and the rear side pressure guide pipe 34 as the pressure guide pipes of the outlet side differential pressure type flowmeter 3 are connected by a bypass pipe 4. Then, when the air is bleeded from the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3, the cooling water W flowing in the inlet side pipe 12 under a positive pressure environment is guided to the front side through the bypass pipe 4. It is directly pumped to the pressure tube 33 and the rear pressure guiding tube 34. As a result, in the cooling facility 10 in which the inside of the inlet pipe 12 installed on the inlet side of the object to be cooled 11 is in a positive pressure environment and the inside of the outlet pipe 13 is in a negative pressure environment, the flow flows in the outlet pipe 13. It is possible to easily and surely bleed the air from the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3 for measuring the flow rate of the cooling water W.

Further, according to the flow rate measuring device 1 according to the first embodiment, a pressure drop source (orifice 21a) is installed in the inlet pipe 12. Then, the bypass pipe 4 is branched from a position on the upstream side (left side, front side in FIG. 2) of the installation position of the pressure drop source (orifice 21a) of the inlet side pipe 12. Then, the bypass pipe 4 is connected to the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3. As a result, the positive pressure in the inlet pipe 12 can be taken out more reliably than when the pressure drop source is not installed in the inlet pipe 12, and the front pressure pipe 33 and the rear pressure pipe 34 of the outlet differential pressure type flow meter 3 can be taken out. The cooling water W flowing in the inlet side pipe 12 under a positive pressure environment at the time of bleeding air can be reliably pumped to the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 via the bypass pipe 4.
Further, according to the flow rate measuring device according to the first embodiment, the flow rate of the cooling water W flowing in the inlet pipe 12 is measured by the inlet differential pressure type flow meter 2 provided with the orifice plate 21, so that the outlet pipe 13 It is possible to measure the flow rate of the cooling water W flowing not only inside but also inside the inlet pipe 12.

(Second Embodiment)
Next, the flow rate measuring device according to the second embodiment of the present invention will be described with reference to FIG. In FIG. 3, the same members as those shown in FIG. 2 are designated by the same reference numerals, and the description thereof may be omitted.
The flow rate measuring device 1 according to the second embodiment shown in FIG. 3 has the same basic configuration as the flow rate measuring device 1 shown in FIG. 2, but unlike the flow rate measuring device 1 shown in FIG. 2, an inlet differential pressure type flow meter. 2 is not provided.
However, the inlet pipe 12 is provided with an orifice plate 21 installed so as to cross the inlet pipe 12. The orifice plate 21 is the same as the orifice plate 21 used in the inlet differential pressure type flow meter 2 of the flow measuring device 1 according to the first embodiment shown in FIG. 2, and the outer diameter is larger than the inner diameter of the inlet pipe 12. Also has a small orifice 21a. The orifice 21a constitutes a pressure drop source.

Then, the bypass pipe 4 is branched from the position on the upstream side (left side, front side in FIG. 3) of the installation position of the orifice plate 21 (orifice 21a) of the inlet side pipe 12, and is on the front side of the outlet side differential pressure type flow meter 3. It is connected to the pressure guiding pipe 33 and the rear pressure guiding pipe 34. The bypass pipe 4 includes a first bypass pipe 50 that branches from the upstream side of the installation position of the orifice plate 21 (orifice 21a) of the inlet pipe 12, and a second bypass that extends from the end of the first bypass pipe 50. It is provided with a pipe 51. Further, the bypass pipe 4 is branched from the second bypass pipe 51 and is connected to the air bleeding valve 38a connected to the front first pressure guiding pipe 33a of the front side pressure guiding pipe 33 of the outlet side differential pressure type flow meter 3. A third bypass pipe 52 is provided. Further, the bypass pipe 4 extends from the end of the second bypass pipe 51 and is connected to the rear first pressure guiding pipe 34a of the rear pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3. A fourth bypass pipe 53 connected to the vent valve 38b is provided.

The flow rate measuring device 1 according to the second embodiment is suitable when it is not necessary to measure the flow rate in the inlet pipe 12, and the differential pressure transmitter 22 and the pressure equalizing valve 27 used in the inlet differential pressure type flow meter 2. Etc. can be omitted.
In the flow rate measuring device 1 according to the second embodiment, when bleeding air from the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3, the air bleeding valve 38a, the air bleeding valve 38b, and the main valve 35a , And open the main valve 35b. As a result, the cooling water W flowing in the inlet pipe 12 under a positive pressure environment is directed to the front side via the first bypass pipe 50, the second bypass pipe 51, and the third bypass pipe 52, as shown by the arrows in FIG. It is pumped to the front first pressure guiding pipe 33a of the pressure guiding pipe 33, and is also pressure fed to the rear first pressure guiding pipe 34a of the rear pressure guiding pipe 34 via the fourth bypass pipe 53. As a result, the inside of the front side first pressure guiding pipe 33a and the inside of the rear side first pressure guiding pipe 34a of the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3 are completely filled with the cooling water W. Then, the cooling water W containing air is discharged from the outlet pipe 13 to the drainage tank 14. As a result, the air is evacuated from the front side first pressure guiding pipe 33a and the rear side first pressure guiding pipe 34a of the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3 from the outside. You can do it without doing it.

Further, when bleeding air from the front side second pressure guiding pipe 33b and the rear side second pressure guiding pipe 34b of the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3, the main valve 35a and the original With the valve 35b closed, the air bleeding valve 38a, the air bleeding valve 38b, the stop valve 36a, the stop valve 36b, and the drain valve (not shown) are opened. As a result, the cooling water W flowing in the inlet pipe 12 under a positive pressure environment is passed through the first bypass pipe 50, the second bypass pipe 51, and the third bypass pipe 52 to the front second guide of the front pressure guide pipe 33. It is pumped to the pressure pipe 33b and also to the rear second pressure guiding pipe 34b via the fourth bypass pipe 53. As a result, the inside of the front side second pressure guiding pipe 33b and the inside of the rear side second pressure guiding pipe 34b of the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3 are completely filled with the cooling water W. Then, the cooling water W containing air is discharged from the drain valve. As a result, the air is evacuated from the front side second pressure guiding pipe 33b and the rear side second pressure guiding pipe 34b of the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3, and the atmosphere is sucked from the outside. You can do it without doing it.

Even with the flow rate measuring device 1 according to the second embodiment configured in this way, in the cooling facility 10 (see FIG. 1), the inside of the inlet side pipe 12 is under a positive pressure environment and the inside of the outlet side pipe 13 is under a negative pressure environment. In the flow rate measuring device 1 in the above, the inlet side pipe 12 and the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 as the pressure guiding pipes of the outlet side differential pressure type flow meter 3 are connected by a bypass pipe 4. Then, when the air is bleeded from the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3, the cooling water W flowing in the inlet side pipe 12 under a positive pressure environment is guided to the front side through the bypass pipe 4. It is directly pumped to the pressure tube 33 and the rear pressure guiding tube 34. As a result, in the cooling facility 10 in which the inside of the inlet pipe 12 installed on the inlet side of the object to be cooled 11 is in a positive pressure environment and the inside of the outlet pipe 13 is in a negative pressure environment, the flow flows in the outlet pipe 13. It is possible to easily and surely bleed the air from the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3 for measuring the flow rate of the cooling water W.

Further, the flow rate measuring device 1 according to the second embodiment also has a pressure drop source (orifice 21a) installed in the inlet pipe 12. Then, the bypass pipe 4 is branched from a position on the upstream side (left side, front side in FIG. 2) of the installation position of the pressure drop source (orifice 21a) of the inlet side pipe 12. Then, the bypass pipe 4 is connected to the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 of the outlet side differential pressure type flow meter 3. As a result, the positive pressure in the inlet pipe 12 can be taken out more reliably than when the pressure drop source is not installed in the inlet pipe 12, and the front pressure pipe 33 and the rear pressure pipe 34 of the outlet differential pressure type flow meter 3 can be taken out. The cooling water W flowing in the inlet side pipe 12 under a positive pressure environment at the time of bleeding air can be reliably pumped to the front side pressure guiding pipe 33 and the rear side pressure guiding pipe 34 via the bypass pipe 4.

Although the embodiments of the present invention have been described above, the present invention is not limited to this, and various modifications and improvements can be made.
For example, the configuration of the output side differential pressure type flowmeter 3 in the first embodiment and the second embodiment needs to include an orifice plate 31, a front side pressure guiding tube 33, a rear side pressure guiding tube 34, and a differential pressure transmitter 32. However, it can be selected as needed, including the configuration and number of other valves. The same applies to the configuration of the inlet differential pressure type flow meter 2 in the first embodiment.
Further, in the second embodiment, the orifice plate 21 having the orifice 21a formed as a pressure drop source is installed in the inlet pipe 12, but this pressure drop source does not necessarily have to be installed.
Further, in the second embodiment, the orifice 21a is used as a pressure drop source, but the pressure drop source does not have to be the orifice 21a, and may be, for example, a throttle.

1 Flow measuring device 2 Input side differential pressure type flow meter 3 Outside differential pressure type flow meter 4 Bypass pipe 10 Cooling equipment 11 Cooling object 12 Input side piping 13 Outlet side piping 14 Drainage tank 21 Orifice plate 21a Orifice plate (pressure drop source)
22 Differential pressure transmitter 23 Front side pressure guiding pipe 23a Front side first pressure guiding pipe 23b Front side second pressure guiding pipe 24 Rear side pressure guiding pipe 24a Rear side first pressure guiding pipe 24b Rear side second pressure guiding pipe 25a, 25b Main valve 26a , 26b Stop valve 27 Pressure equalizing valve 27a Branch pipe 28a, 28b Air bleeding valve 31 Orifice plate 31a Orifice 32 Differential pressure transmitter 33 Front side pressure guiding pipe (pressure guiding pipe)
33a Front side first pressure guiding pipe 33b Front side second pressure guiding pipe 34 Rear side pressure guiding pipe (pressure guiding pipe)
34a Rear side 1st pressure guiding pipe 34b Rear side 2nd pressure guiding pipe 35a, 35b Main valve 36a, 36b Stop valve 37 Pressure equalizing valve 37a Branch pipe 38a, 38b Air bleeding valve 40 1st bypass pipe 41 2nd bypass pipe 42 3 Bypass pipe 43 4th bypass pipe 44 Air bleeding valve 45 Air bleeding valve 50 1st bypass pipe 51 2nd bypass pipe 52 3rd bypass pipe 53 4th bypass pipe W Cooling water

Claims (4)

The cooling water flowing in the inlet pipe installed on the inlet side of the object to be cooled circulates in the object to be cooled to cool the object to be cooled, and the cooling water obtained by cooling the object to be cooled is the object to be cooled. A flow measuring device that measures the flow rate of cooling water flowing through the outlet pipe of a cooling facility installed on the outlet side of the cooling facility with a differential pressure type flow meter. In the equipment, in a flow rate measuring device in which the inside of the inlet pipe is in a positive pressure environment and the inside of the outlet pipe is in a negative pressure environment.
The cooling water that flows through the inlet pipe and the pressure guiding pipe of the outlet side differential pressure type flow meter in a positive pressure environment when air is bleeded from the pressure guiding pipe of the outlet side differential pressure type flow meter. A flow rate measuring device characterized in that it is connected to a pressure guiding pipe by a bypass pipe that directly pumps water. A pressure drop source is installed in the inlet pipe, and the bypass pipe is branched from a position upstream of the installation position of the pressure drop source in the inlet pipe to form a pressure guiding pipe of the outlet differential pressure flowmeter. The flow rate measuring device according to claim 1, wherein the flow rate measuring device is connected. The pressure drop source according to claim 2, wherein the pressure drop source is an orifice formed on an orifice plate installed so as to cross the inlet pipe and having an outer diameter smaller than the inner diameter of the inlet pipe. Flow measuring device. The flow rate measuring device according to claim 3, wherein the flow rate of the cooling water flowing in the inlet pipe is measured by an inlet differential pressure type flow meter provided with the orifice plate.

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