JPS62261017A - Measuring instrument for variate element of fluid - Google Patents

Abstract

PURPOSE:To enable the variate element of a fluid to be measured with a high reliability by providing a lead piping with a pressure pulsation preventing device having a plurality of communication holes to decrease the effect of a pressure pulsation. CONSTITUTION:Pressure pulsation preventing devices 26 are provided in lead pipings 7 and 12 connected to the high pressure side detector 8 and the low pressure side detector 13 of a flowmeter 14, respectively. Each preventing device 26 is formed with a plurality of thin communication holes 28, 28... in parallel to one another in the longitudinal direction of the device 26 and threadedly connected to the lead piping 7 or 12. Thus, when a pressure pulsation and a transient pressure change or a flow change are generated in a main steam pipe 2, a pressure wave corresponding thereto is propagated in the pipelines 7 and 12. The pressure change due to the pressure wave reaches a plurality of the holes 28 of the preventing devices 26 and the pressure pulsation of a fluid is damped by the restriction effect of the holes 28, 28... to suppress a dynamic pressure propagation. Accordingly, an always stable and accurate flow rate measurement can be conducted.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) Mr. Kinoe Akiban, please describe the fluid change summary consisting of the pressure, flow rate, etc. of the fluid in which pressure pulsation occurs. 13! A device for measuring variable elements in fluids that can be measured without being affected by I will.

(Prior art) In general, fluids that generate pressure pulsations when measuring the change in fluid (for example, steam in the main steam pipe generated in a nuclear reactor and led to the turbine), There is a fluid cap on the discharge side that is delivered by the pump.

Conventionally, we have been able to measure the pressure and flow rate in the piping where such steam flow occurs, or the pressure and flow rate in the piping on the outlet side of the pump! δ is being measured, but inside the pipe a-;
J: Due to the pressure pulsations occurring in the pipes leading to the flow of fluid for measurement, the 81 measurement instruction (B 1b fluctuates following the pressure saw pulse 5h and may become unstable). It was small.

In particular, in flowmeters, it is common to provide a constriction-like structure in the piping and measure the flow rate from the differential pressure generated between the upstream and downstream sections, but the 81 measurement range for differential pressure J1 is generally Because it was small, it was susceptible to the aforementioned pressure horn pulsation.

Nozzles, venturis, orifices, etc. are used in this aperture mechanism, and these will be collectively referred to as flowniremen I.
It is called.

For example, in the main steam pipe of a boiling water nuclear power plant, as shown in FIG. Steam is transferred from the inlet side pressure detection end 4 of 3 to the pressure guidance pipe 5
The pressure obtained by condensing W is passed through the pressure piping 7 to the high-pressure side detection part 8 of the flow meter 14, and is applied as a pressure of 1''. In addition, steam is also led out from the throat side pressure detection end 9 of the flow element 3 via the pressure piping 10 and guided to the condensation tank 11, and the pressure obtained in the condensation tank 11 is passed through the pressure piping 12. This is applied to the low pressure side detection section 13 of the flowmeter 14 as throat pressure. The flow rate of steam is measured each time the pressure difference between the inlet pressure and the throat pressure is measured. Each pressure piping 7, 12 is connected to a flow section 2 of the reactor containment vessel 25, respectively.
5a.

25b is penetrated.

The flow meter 14 issues a detection signal when the steam flow in the main steam pipe 2 exceeds a set value. This detection signal is used as an important safety signal to close a main steam isolation valve (not shown) and scram the reactor in the event that the main steam pipe 2 on the downstream side is ruptured.

(Problem to be Solved by the Invention) However, in this type of measurement between steam flows or in the measurement of pump discharge pressure and discharge flow rate, the pulsating pressure is relatively large, and the detection signal has a constant large noise. There was a problem with being included.

In addition, during the side valve opening test of the main steam isolation valve or when the turbine inlet pressure regulator is activated, transient pressure fluctuations and flow m fluctuations occur in the main steam pipe 2, and the pressure waves are transmitted to the pressure guide pipe 7.
12, and the pressure measured at the high-pressure piping side detection end 8 and the low-pressure side detection end 13 is a damped oscillation! This may cause IJ. At that time, the fluid in the pressure piping 7 and 12 is
Because it vibrates at a rotating frequency determined mainly by the length of each piping, generally the pressure attenuation imaging measured by the high-pressure side detection section 8 and the low-pressure side detection section 13, respectively, is caused by vibration! l
A mode in which the I number, amplitude, etc. become violet.

For this reason, in the flow meter 14, which measures the differential pressure between two pressures and generates a detection signal, the transient Observations 1) Upper flow V11 fluctuations may appear, and there is also a possibility that the flow fluctuations will be further exacerbated.

For example, as shown in Figure 7, the signal for the measured flow rate Q is normal. During transient changes that occurred at times, the actual flow n .

This J: To stop the reactor at the time of pressure change in the main steam pipe 2 a3 and the slight transient change in flow rate +1'5 [
Although this can be said to be a safe measure from the perspective of preventing t'JS accidents, it poses problems in terms of a decline in the operating rate of nuclear power plants and the resulting stable supply of electricity.

Therefore, in the conventional pressure measuring device and flow rate measuring device for piping where pressure fluctuations are likely to occur, the method shown in Fig. 8 1. Nijo? J'
J: When the output circuit 15 of the sea urchin flowmeter 14 is resisted, a filter circuit 18 consisting of a condenser 1 and 17 is provided, and the filter circuit 18 damps vibrations. There is a device in which an output signal 19 is obtained.

However, since this device newly added an electric filter circuit 18, there was a problem with the measurement reliability f1 due to the increase in the number of parts. A different kind of 1rl l that occurs! 2 could not be prevented.

In addition, mechanically, as shown in FIG. 0, a bottle 23.
4 is inserted to prevent the 1F force pulsation due to the throttle, but this yj method also prevents dust from filling up.
Measuring circle 5 due to clogging in 2! ■There is a possibility that
Maintainability J: and 13・i (I was worried about fl.

The present invention has been made in view of these points, and it reduces the influence of pressure pulsations when measuring variable factors of fluid such as pressure and flow rate of fluid in piping, and furthermore, it is possible to reduce the influence of pressure pulsation even when pressure fluctuates. It is an object of the present invention to provide a highly reliable fluid variable element measuring device that can stably and accurately measure and display and protect the instrument.

[Structure of the invention]

(Means for Solving the Problems) The fluid variable element measuring device of the present invention includes a pressure piping that leads the fluid in a flow path from the flow path for iit 1lll, and a fluid guided by the pressure piping. In a device for measuring a variable element of a fluid having an ε1 measurement structure for measuring a variable element of a fluid such as pressure or flow rate of an incoming fluid, is it possible to reduce pressure pulsations occurring in the flow path and pressure piping? ! J￥1
A pressure pulsation preventer having a communication hole is provided in the pressure guiding pipe.

(Function) In the present invention, the pressure pulsations of the fluid generated in the flow path or the pressure piping are suppressed by the flow pulsation when the fluid flows through the plurality of narrow communication holes of the pressure pulsation preventer. The throttle effect suppresses dynamic pressure propagation to the downstream side. In addition, it is impossible for the fluid that is not affected by pressure pulsation to be shifted to the ε1 measurement structure downstream of the pressure pulsation preventer, and the measurement structure prevents Tt force pulsation. IJI
Be able to accurately measure the pressure and flow υ of the fluid.

In addition, since a plurality of conduction holes are formed, two conduction holes are not blocked at the same time, and measurement can always be carried out stably and reliably.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 5.

FIG. 1 shows an overview of this embodiment. In this embodiment, the flow rate of the main steam of the B-Takuryo Power Plant is targeted as a variable element of the fluid to be measured.

In FIG. 1, the same parts as in the prior art are denoted by the same reference numerals as in FIG.

゛In this example, measure! Each impulse piping 7 is connected to the impulse piping 7 and 12 which are respectively connected to the high pressure side detection part 8 and the low pressure side detection part 13 of the flow meter 14 which is a type of mechanism.
．． A pressure pulsation preventer 26 is provided to attenuate the pressure pulsation of the fluid generated in the fluid 12 and guide it to the 1ffoil 14 on the downstream side. The rest of the structure is the same as the conventional example shown in FIG.

2 and 3 show one embodiment of the pressure pulsation preventer 26. FIG.

The pressure pulsation preventer 26 of this embodiment has a cylindrical main body 27 with a plurality of thin conductive holes 28, 28, etc. formed in parallel in the longitudinal direction thereof, and TM threaded portions at both ends. 29
．． 29 is provided to form a threaded connection with the pressure piping 7.12. In this embodiment, the pressure pulsations of the fluid can be attenuated by the throttling effect of the plurality of conduction holes 28, 28, . . . . .

FIG. 1 shows another pressure pulsation preventer 268, in which the connections at both ends of the main body 27 are connected to the pressure piping 7,
A piping joint 30, 30 was installed at the end of the pipe 12 so that it could be easily connected without forming a thread. This pipe joint 30 is an annular wedge-shaped ring 31.3 inserted between the i9 pressure pipe 7.12 and the main body 27.
1 and a bag put 32 that tightens the ring 31.Next, a flow rate measuring method according to the first embodiment will be explained.

In Fig. 2, when pressure pulsations and transient pressure changes or flow rate changes occur in the main steam pipe 2, a corresponding pressure wave is transmitted through the pipes 7 a3 and 12.
Jru. This pressure fluctuation is mainly caused by the pulsating pressure of this pressure pulsation and pressure wave (the circumference is mainly determined by the length of the pressure piping 7.12).This pressure fluctuation prevents the pressure horn pulsation. The plurality of conduction holes 28/\reaching gap of the vessel 26.The conduction holes 28 (the constriction effect determined by the friction coefficient 1 of the equation below) have the effect of suppressing dynamic pressure propagation.

F = L / n D.

Here, l: X7 hole length D: Inner diameter of conduction hole r) Ni and F through Kokigan It is.

This l''F + dormitory coefficient F has the relationship of -F formula, therefore, either the diameter of each of the through holes 28 is made smaller or the through hole 2
By making the length of 8 longer, for example, in a lahin shape, the effect of damping pressure pulsations is increased.

J: Therefore, the fluid flowing through these communication holes 28, 28, etc. is not affected by pressure pulsations. As a result, the pressure pulsation peaks and transient pressure wave peaks in both the detection parts 8 and 13 of the flow meter 14 are significantly attenuated, and this flow meter can always stably and accurately measure the flow rate. can be done.

In addition, since a plurality of conductive holes 28 are provided, there is a very low possibility that all of them will become clogged at the same time.
The reliability of l measurements is poor.

In this way, even if there is a pressure fluctuation in the main steam pipe 2, the pressure waves propagating through the impulse piping 7 and 12 are placed in front of the high-pressure side detection section 8 and the low-pressure side detection section 13 of the flowmeter 14. The effect of pressure pulsation can be sufficiently reduced by the pressure pulsation preventer 26.

This prevents large pressure pulsations from being applied directly to the flow and TI meter 1/I, and prevents loss (force) of the flow meter 14. Even when transient pressure fluctuations or flow Ed fluctuations occur in the main steam pipe 2, the Tantei 14 keeps the measured flow rate Q close to the actual flow rate QQ, and maintains the amplitude of the indicated vibration of the measured flow Q. It becomes possible to reduce the amount of clay to one shift, which is not a problem even when compared to the plant shutdown level Q.

To further explain, in the 11 examples of nuts, the high pressure side detection section 8 Jj of the differential pressure type flow rate h114 and the low pressure side detection section 13
By providing the force pulsation J preventer 26, which is equipped with a plurality of small-diameter communication holes 28, 28... in both impulse piping 7.12 connected to the In order to reduce it, during transient pressure fluctuations, the relatively high frequency flow determined by the length of the instrumentation piping due to the natural vibration of the fire can overwhelm the apparent indication vibration of 414 to as small as 1 min. Since a plurality of conductive holes 28 are provided in the palm, the possibility of clogging can be reduced.

As a result, the stability of the 11Q constant due to leakage is improved, and the possibility of generating an erroneous signal due to indication vibration is reduced, increasing reliability.

In addition, in the above embodiment, the measurement of the flow m in the main steam pipe 2 of a nuclear reactor was explained, but the fluid in other pipes was measured by X:
The same method can be used to measure flow rate by measuring pressure. Naturally, the same method can also be applied to pressure measurements.

〔Effect of the invention〕

Since the measuring device for variable elements of fluid according to the present invention is constructed and operated in this manner, it is possible to detect pressure pulsation when measuring the pressure of the fluid in piping or the variable element of the fluid at the customer's flow rate. Furthermore, even when pressure fluctuates, measurement and display can always be performed stably and accurately.
．． It has the following effects: high reliability and high reliability.

[Brief explanation of drawings]

Fig. 1 is a piping system diagram showing an embodiment of the measurement 5A neck of the fluid variable ffl element of the present invention, and Fig.
:A cross-sectional view, not showing an example of a force pulsation preventer.
4 is a cross-sectional view of another embodiment of the force pulsation preventer, and FIG. 5 is an output waveform diagram for explaining the present invention in detail. Fig. 6 is a piping system diagram without showing a conventional reactor main steam pipe flow τd measurement device, Fig. 7 is an output waveform diagram of the flow rate 51 during pressure fluctuations in the reactor main steam pipe,
FIG. 8 is a circuit diagram showing a conventional filter circuit, and FIG. 9 is a sectional view showing a conventional mechanical aperture mechanism. 2...Main steam pipe, 5.7.10.12...Leading L1 piping, 1/1...Flow φ meter (differential pressure δt), 26...Pressure pulsation preventer, 28... Conduction hole, 30...piping joint. Applicant's agent: S -JJL 1 Diagram 4 Figure To Time Figure 6 TO Time Figure 6

Claims (1)

[Claims] 1. A pressure piping that leads the fluid in a flow path from the flow path for measurement, and measurement of variable elements of the fluid such as pressure or flow rate of the fluid guided by the pressure piping. In the device for measuring a variable element of a fluid, the pressure pulsation preventer having a plurality of communication holes that reduces pressure pulsations occurring in the flow path and the pressure piping is provided in the pressure piping. A device for measuring variable elements of a fluid, characterized in that: 2. The pressure pulsation preventer is formed by providing piping connections at both ends of the main body, which has multiple conduction holes, and piping joints are integrally incorporated into these piping connections. An apparatus for measuring a variable element of a fluid according to claim 1, characterized in that: