JPH04133108A - Flow rate control valve and flow rate measuring instrument using this valve - Google Patents

Abstract

PURPOSE:To detect the pressure of a primary side and a secondary side pipings and to obtain the data required for measuring a flow rate by providing a through-hole on a valve casing, and attaching a pressure sensor to this through- hole, respectively. CONSTITUTION:An air conditioner 12 is provided with a heat exchanger 14, and to its inlet part 16 and outlet part 18, a supply piping 20 and an exhaust piping 22 allowed to branch from a main piping are connected, respectively. In the vicinity of the heat exchanger 14, a blower 24 is provided, and by driving this blower 24, the open air is led into a room. Air blown out of the blower 24 passes through the heat exchanger 14, by which a heat exchange is executed, and temperature control is executed. That is, this instrument is constituted so that a fluid being a medium for the heat exchange is allowed to circulate between a duct line of the supply piping 20 and a duct line of the exhaust piping 22.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flow rate control valve that controls the flow rate of fluid passing through a heat exchanger, and a flow rate measuring device using this flow rate control valve.

[Prior art]

BACKGROUND ART Conventionally, in air conditioning equipment for buildings and the like, the set temperature differs for each room, so it is necessary to adjust the flow rate of fluid (cold water, hot water) circulating through the heat exchanger of the air conditioner.

For this reason, each air conditioner is provided with a flow control valve at an independently piped portion, and a flow meter that is paired with the flow control valve is also provided in parallel.

As flowmeters applied to air conditioners, turbine (propeller) type flowmeters and area type flowmeters, which have relatively simple structures, are often used.

However, the flowmeter described above has the problem of requiring a large installation space because it must be installed separately from the flow rate control valve. Furthermore, although a flow meter will be installed for each of the air conditioners, the straight pipe section should be of a predetermined length near the installation location of the flow meter due to the characteristics of the flow meter, and the fluid in the pipe must flow laminarly.
The measurement error increases. However, since the machine room where the piping of each air conditioner is concentrated is narrow, it is difficult to secure the above-mentioned piping space.

Note that a throttle valve type flow meter is available as a method for measuring the flow rate in a pipe. This principle is based on Bernoulli's theorem, where a throttle valve is provided in the pipeline, and the pressure difference between the pressure in the primary pipeline and the pressure in the secondary pipeline is measured across the throttle valve.
The configuration is such that the flow rate is calculated from this pressure difference, the opening area of the throttle valve, and the density of the fluid (see the formula below).

p v'+ P s = P t (1) However, ρ:
density of fluid, V: flow velocity, PS: static pressure, Pt: total pressure.

By using this throttle valve type flowmeter, there is no need for laminar flow.
The piping space for installing the flowmeter is small.

[Problem to be solved by the invention]

However, in the above-mentioned throttle valve type flowmeter, it is necessary to assemble a throttle valve, a pair of pressure sensors, a throttle valve opening sensor, etc. for each air conditioner, which results in poor assembly workability.

The present invention has been made in consideration of the above facts, and an object of the present invention is to obtain a flow control valve capable of detecting the primary side pipe pressure, the secondary side pipe pressure, and the opening degree of the valve body necessary for flow measurement.

In addition to the above objectives, by integrating the flow control function and flow measurement function, the piping space for installing the flowmeter can be reduced, and the flow rate control can improve assembly workability. The purpose is to obtain a flow rate measuring device using a valve.

[Means to solve the problem]

The invention described in claim (1) includes a valve body that changes the flow rate of fluid circulating through a heat exchanger through an opening/closing operation, and a valve body disposed with the valve body and a valve body that changes the flow rate of fluid circulating through a heat exchanger through an opening/closing operation. The valve casing includes a valve casing in which a through hole is formed to communicate with each of the through holes, a pair of pressure sensors attached to each of the through holes, and an opening detection sensor that detects the opening degree of the valve body.

The invention according to claim (2) includes a valve body that changes the flow rate of fluid circulating through a heat exchanger through an opening/closing operation, and a valve body provided with the valve body and a valve body that changes the flow rate of fluid circulating through a heat exchanger through an opening/closing operation. a valve casing in which a through hole is formed to communicate with each other; a pair of pressure sensors attached to each of the through holes; an opening detection sensor that detects the opening degree of the valve body; a storage means storing a flow rate correction coefficient based on the degree;
The flow rate is calculated based on the differential pressure between the primary side pipe pressure and the secondary side pipe pressure detected by the pair of pressure sensors and a flow rate correction coefficient based on the opening degree of the valve body obtained from the storage means. Flow rate calculation means.

[Effect]

According to the invention described in claim (1), the valve casing is provided with a through hole, and a pressure sensor is attached to each of the through holes, so that the pressure in the primary side piping and the pressure in the secondary side piping bordering the valve body can be adjusted. and can be detected. Further, the opening degree of the valve body can be detected by an opening detection sensor, and the valve body for controlling the flow rate can be used as a throttle valve for measuring the flow rate. Therefore, the flow rate control valve of the present invention is installed. You can obtain the data necessary for flow measurement with just one. Therefore, there is no need to separately attach parts for flow rate measurement, and assembly work efficiency is improved.

In the invention according to claim (2), the calculation means uses signals from the pressure sensor and the opening detection sensor attached to the flow control valve and a correction coefficient specific to the flow control valve stored in the storage means. The flow rate can be measured by That is, since the flow rate can be measured without laminar flow of fluid, a long straight pipe section for laminar flow is not required, and the piping space for flow measurement can be reduced.

〔Example〕

FIG. 1 and FIG. 2 show a flow control valve 1 according to this embodiment.
An air conditioner 12 with 0 applied is shown. Air conditioner 12
is equipped with a heat exchanger 14, and this heat exchanger 14 includes:
A supply pipe 20 and a discharge pipe 22 branched from a main pipe (not shown) are connected to the inlet section 16 and outlet section 18, respectively. A blower 24 is disposed near the heat exchanger 14, and when the blower 24 is driven, outside air is introduced into the room.

Here, the air blown out from the blower 24 passes through the heat exchanger 14 to undergo heat exchange and temperature adjustment. That is, between the supply piping 20 and the discharge piping 22, a fluid (
The structure is such that hot water or cold water is circulated.

The regulated temperature varies depending on the flow rate of the fluid. The flow rate is regulated by a flow control valve 10 disposed in the middle of the discharge pipe 22.

As shown in FIG. 3, the flow control valve 10 has flanges 28 and 30 formed at both axial ends of a cylindrical valve casing 26 with a hollow interior. The flanges 28 and 30 are each connected to a flange 32 on the exhaust pressure pipe 22 side.

A valve body 34 is disposed at an intermediate portion in the fluid flow direction within the valve casing 26, and partitions the pipe line within the valve casing 26 into a primary pipe line 36 and a secondary pipe line 38. The base of the valve body 34 is a shaft rod 34A, and extends through the peripheral wall of the valve casing 26 to the valve body drive section 40. The valve body driving unit 40 adjusts the degree of opening of the pipeline by the valve body 34 by moving the axis of the shaft 34A to close or open the downstream pipeline 36 and the secondary pipeline 38. are doing. The opening degree of this valve body 34 is detected by an opening degree sensor 42, as shown in FIG.

As shown in FIGS. 3 and 4, the opening sensor 42 is provided on the outside of the casing 44 of the valve body drive unit 40, and in accordance with the axial movement of the valve body 34, opens in the direction perpendicular to its own axis. The movement of the valve body 34 is linked by a moving pin 46.

The pin 46 passes through an elongated hole 48 provided in the casing 44 and whose longitudinal direction is in the vertical direction in FIG. 4, and is connected to a pointer arm 50 that is rotatable about a shaft 54. The pin 46 is housed in a long hole 52 formed along the length of the pointer arm 50. Therefore, the pointer arm 50 is configured to rotate around the shaft 54 in accordance with the movement of the pin 46.

A sub-casing 56 is attached to the casing 44 so as to include the rotation range space of the pointer arm 50 (see FIG. 3). The sub-casing 56 is dish-shaped and provided with a fan-shaped window 58 corresponding to the locus of movement of the tip of the pointer arm 50. Therefore, the tip of the pointer arm 50 can be visually observed through this window 58. A transparent cover 60 is attached to the window 58, and a scale 62 is engraved thereon. The engraving width of this scale 62 is determined by the principle shown below.

The pointer arm 50 is perpendicular to the axis of the valve body 34 when the valve body 34 completely closes the conduit in the valve casing 26 (horizontal state in FIG. 3). From this state, when the valve body 34 is axially moved in the direction of opening the pipe, the pin 46 is moved from one end of the elongated hole 48 to the other end by the cam action of the pin 46 and the elongated hole 48. The pointer arm 50 is tilted at an angle θ accordingly. This angle θ is determined by the distance A between the shaft 54 and the pin 46 and the amount of movement X of the valve body 34 from the fully closed state of the pipe (θ=tan −'
(X/A>...'(2)). In other words, the amount of movement
The smaller the amount of change in angle θ, the greater the amount of change in angle θ, and as the amount of movement X increases, the amount of change in angle θ becomes smaller.
The scale width of the scale 62 obtained by equally dividing the amount of movement of 4 becomes gradually narrower from the fully open state to the fully open state (see FIG. 4).

Further, a plurality of contact points 64 are evenly distributed on the casing 44 along the movement locus of the pointer arm 50. Thereby, the opening degree of the valve body 34 can be electrically recognized according to the movement of the pointer arm 50. In the opening sensor 42 having the above configuration, the number of contacts 64 that can be accommodated within one scale increases in the region near the fully open position, so the opening of the valve body 34 can be detected with high accuracy.

As shown in FIG. 3, through holes 66 are formed in the seven flange 28, 30 of the valve casing 26 and communicate with the downstream pipe line 36 and the secondary pipe line 38, respectively. Pressure sensors 68 and 70 are attached to the through holes 66, respectively, and can detect the pressure of the fluid flowing in the downstream pipe line 36 and the pressure of the fluid flowing in the secondary pipe line 38.

As shown in FIG. 2, the signal lines 72,74 of the pressure sensors 68,70 are each connected to a differential pressure meter 76 to supply the detected pressure to the differential pressure meter 76.

The differential pressure meter 76 obtains the differential pressure between the manually input pressure of the primary side pipe line 36 and the pressure of the secondary side pipe line 38, and controls the control device 78.
It has the role of supplying

A signal line 80 from each contact 64 of the opening sensor 42 is connected to this control device 78 . As shown in FIG. 5, the control device 78 includes a microcomputer 82, which includes a CPU 84, a RAM 86, a ROM 88, a human output port 90, and a data bus and control bus that connect these. It is composed of a bus 92 such as.

A signal line 94 from the differential pressure meter 76 and a signal line 80 from the contact 64 of the opening sensor 42 are connected to the human output port 90 via an A/D converter 75.

Further, this input/output port 90 is connected via a LAN (local area network) 98 to a central monitoring panel 96 that centrally controls the plurality of air conditioners 12 .

In addition, indicators 91 and 93 are connected to the input/output port 90 and the central monitoring panel 96, respectively, so that the flow rate and the like can be displayed.

The RAM 86 stores a map of flow rate correction coefficients (CV values) that correspond to the valve opening specific to the flow rate control valve 10 applied to this embodiment (see FIG. 6). This CV
The value includes the degree of opening of the opening area depending on the opening degree of the valve body, and is applied as a correction coefficient when obtaining the flow rate based on the pressure difference between the downstream pipe line 36 and the secondary side pipe line 38.

The operation of this embodiment will be explained below with reference to the flowchart of FIG.

In step 100, when the flow rate control valve 10 is opened from the fully closed state, the process moves to step 102, where the signal from the contact point 64 of the opening sensor 42 is read, and the current valve body 3 is read.
Detect the opening degree of 4. Next, in the discard 104, the RAM
Valve body 3 is selected from the map stored in 86 (see Fig. 6).
Read the CV value based on the opening degree of No.4. Next, step 1
In step 06, the pressure of the fluid in the primary pipe line 36 is detected from the pressure sensor 68, and then in step 108, the pressure sensor 70 is detected.
The pressure of the fluid in the secondary pipe line 38 is detected from Step 1.
Move to 10.

In step 110, the differential pressure meter 76 detects the pressure difference between the pressure in the primary pipe line 36 and the pressure in the secondary pipe line 38. In the next step 112, the flow rate Q is calculated from the differential pressure and the CV value according to the formula below.

Q = B x CV x fτπ7U-(3) This (
Equation 3) is based on Bernoulli's theorem shown in equation (1) above. However, Q: flow rate, B: coefficient, CV: correction coefficient specific to the applied control valve, ΔP: differential pressure, G: specific gravity of liquid when water is 1.

In the next step 114, the calculated flow rate is displayed on the display 91.
Then, in step 116, the calculated flow rate data is supplied to the central monitoring board 96 and displayed on the display 93 (step 118).

The central monitoring panel 96 integrates the flow rate supplied to each air conditioner 12. This makes it possible to charge usage fees to each tenant according to the flow rate of the fluid being circulated.

In the next step 120, it is determined whether or not the opening degree of the valve body 34 has changed. If there is no change, the process moves to step 114 to repeat the display, and if there is a change, the process moves to step 100. and repeat the above steps.

As described above, according to this embodiment, the pressure sensor 68,70 is provided on the flange 28,30 of the flow control valve 10, and the opening sensor 42 is also provided, so that all the data necessary for flow rate measurement can be obtained. This eliminates the need to separately install pressure sensors, throttle valves, etc. in other piping locations.

Further, even when measuring the flow rate of each of the plurality of air conditioners 12, since the flow rate control function and the flow rate measurement function are integrated into one flow rate control valve 10, the assembly work efficiency is improved. Furthermore, since a throttle valve type flowmeter is used, there is no need for laminar flow, and the installation space can be further reduced, resulting in a smaller piping space for flow rate measurement.

In this embodiment, the flow rate of the fluid circulating through the heat exchanger 14 is measured, but as shown in FIG. 8, a temperature sensor 97 is provided in each of the supply piping 20 and the discharge piping 22. 99 is provided, and the temperature difference detected by the temperature sensor 97.99 and the flow rate are used to control the heat exchanger 14.
You may calculate the amount of heat exchanged and charge a usage fee based on the amount of heat (calories) consumed corresponding to this amount of heat exchanged (
(See formula (4)).

K=QxΔTXα (4) However, K: amount of heat; Q: Flow rate, ΔT: temperature difference, α: Measurement Interbanope It is.

This makes it possible to calculate usage fees more accurately than in conventional management, where usage fees are determined based on each tenant's exclusive floor area and usage time.

〔Effect of the invention〕

As explained above, the invention described in claim (1) has the excellent effect of being able to detect the primary side pipe pressure, the secondary side pipe pressure, and the opening degree of the valve body necessary for flow measurement. have

Furthermore, in the invention described in claim (2), by unitizing the flow rate control function and the flow rate measurement function, the piping space for installing the flow meter can be reduced, and the assembly work efficiency is improved. It has the excellent effect of being able to

[Brief explanation of the drawing]

Figure 1 is a schematic piping diagram of the air conditioner according to this embodiment, Figure 2 is an enlarged view of the discharge piping, Figure 3 is a side view of the opening sensor, Figure 4 is a front view of the opening sensor, and Figure 4 is a front view of the opening sensor. Figure 5 is a control block diagram.
FIG. 6 is a valve opening-Cv value characteristic diagram, FIG. 7 is a control flowchart, and FIG. 8 is a schematic piping diagram of an air conditioner in which temperature sensors are installed before and after the heat exchanger. 10...Flow rate control valve, 12...Air conditioner, 14...Heat exchanger, 26/28. 34 ・ 36 ・ 38 ・ 42 ・ 66 ・ 68. 76 ・ 78 ・ ・Valve casing, 0...Flange, ・Valve body, ・-Downstream pipe line, ・Secondary side pipe line, ・Opening degree sensor, ・Through hole, 0...Pressure sensor, ・Difference Pressure meter, ・Control device.

Claims (2)

[Claims] (1) A valve element that changes the flow rate of fluid circulating through the heat exchanger through opening and closing operations, and a through hole in which this valve element is installed and communicates with each of the primary and secondary pipes. 1. A flow control valve comprising: a valve casing having a cylindrical shape, a pair of pressure sensors attached to each of the through holes, and an opening detection sensor for detecting the opening of the valve body. (2) A valve element that changes the flow rate of fluid circulating through the heat exchanger through opening and closing operations, and a through hole in which this valve element is installed and communicates with each of the primary and secondary pipes. a pair of pressure sensors attached to each of the through holes, an opening detection sensor that detects the opening degree of the valve body, and a flow rate correction coefficient that is stored in advance based on the opening degree of the valve body. and a flow rate correction coefficient based on the differential pressure between the primary pipe line pressure and the secondary pipe line pressure detected by the pair of pressure sensors and the opening degree of the valve body obtained from the storing means. A flow rate measuring device using a flow rate control valve, comprising: a flow rate calculation means for calculating a flow rate based on the flow rate.