CN109931999B - Device and method for measuring mass flow rate of small pore channels in reactor - Google Patents

Abstract

The invention belongs to the technical field of nuclear reactor mass flow rate measurement, and particularly relates to a device and a method for measuring the mass flow rate of a small pore canal in a reactor. The invention relates to a device for measuring the mass flow rate of a fine pore canal in a reactor, which comprises a high-level container, an analog pore plate box body, a low-level container and a mass measuring instrument: the liquid in the high-level container flows into the simulated orifice plate box body, and flows into the low-level container through a plurality of tiny through holes on the lower end surface of the simulated orifice plate box body, which are used for simulating tiny pore channels in the nuclear reactor, and the mass measuring instrument measures the mass of the liquid stored in the low-level container. The invention accurately measures the mass flow rate of the tiny holes in the nuclear reactor by calculating the mass flow rate of the simulated orifice plate box body under a certain pressure difference, and has important significance for guaranteeing the service life of related components and the safe operation of the nuclear reactor.

Description

A device and method for measuring mass flow rate of small channels in a reactor

Technical Field

The invention belongs to the technical field of nuclear reactor mass flow rate measurement, and in particular relates to a mass flow rate measurement device and method for a fine channel in a reactor.

Background Art

There are a large number of tiny pores in a nuclear reactor. If the mass flow rate of these tiny pores is insufficient, nucleate boiling will occur in the relevant components of the nuclear reactor, leading to failure and damage of the relevant components. Therefore, accurate measurement of the mass flow rate of these tiny pores is of great significance to the safe operation of nuclear reactors.

Since the aperture of tiny channels in nuclear reactors is too small, it is difficult to accurately measure their mass flow rate with existing technology. This is a technical problem that urgently needs to be solved in the field of nuclear reactor mass flow rate measurement technology.

Summary of the invention

The technical problem to be solved by the present invention is that it is difficult to accurately measure the mass flow rate of fine holes in a nuclear reactor in the prior art.

The technical solution of the present invention is as follows:

A device for measuring mass flow rate of fine channels in a reactor comprises a high-level container, a low-level container and a mass measuring instrument. Liquid in the high-level container flows into the low-level container, and the mass measuring instrument measures the mass of the liquid received by the low-level container. A simulated orifice plate box is provided between the high-level container and the low-level container. The simulated orifice plate box is in a box structure as a whole, with fine through holes on the lower end surface of the box and an open upper end surface of the box. The liquid in the high-level container first flows into the simulated orifice plate box, and then flows into the low-level container through the fine through holes on the lower end surface of the simulated orifice plate box.

As a preferred solution: the mass flow rate measurement device for small channels in the reactor also includes a connecting pipe, the lower end of the high-level container is provided with a through hole, the upper end of the connecting pipe is connected to the through hole of the high-level container, and the lower end extends into the simulation orifice box.

As a preferred solution: the mass flow rate measuring device for a fine channel in a reactor further comprises a valve, through which the opening/closing of the pipe is controlled. The valve is preferably a solenoid valve.

As a preferred solution: the mass measuring instrument is an electronic scale.

As a preferred solution: the liquid contained in the high-level container is water or oil.

A method for measuring the mass flow rate of a fine channel in a reactor using the above device comprises the following steps:

Step S1

Measure the pressure difference △P between the highest liquid level in the high-level container and the lower end surface of the simulated orifice box;

Step S2

The liquid in the high-level container flows into the simulated orifice plate box, and then flows into the low-level container through the fine through-holes on the lower end surface of the simulated orifice plate box;

Step S3

After △t time, the mass m of the liquid received by the low-level container during this period of time is measured by a mass measuring instrument, and the mass flow rate μ of the small through hole under the corresponding pressure difference △P is calculated, μ＝m/△t;

Step S4

Change the liquid level height of the high-level container, repeat steps S1 to S3, record the mass flow rate μ of the small through hole under different pressure differences △P, and draw a "pressure difference △P-mass flow rate μ of the small through hole" curve;

Step S5

During the operation of a nuclear reactor, the pressure difference of relevant components is monitored and compared with the "pressure difference △P-fine through-hole mass flow rate μ" curve; the fine pore mass flow rate of the relevant components is obtained.

As a preferred solution: in step S1, a pressure sensor can be used to measure the pressure difference △P; in step S1, the pressure difference △P can also be determined by measuring the height difference △h from the highest liquid level of the high-level container to the lower end surface of the simulated orifice box, combined with the liquid density ρ and gravity acceleration g in the high-level container. .

As a preferred solution: in step S3, the value of Δt is 5s to 30s.

The beneficial effects of the present invention are:

The present invention provides a device and method for measuring mass flow rate of fine holes in a reactor. By calculating the mass flow rate of a simulated orifice box under a certain pressure difference, the mass flow rate of fine holes in a nuclear reactor is accurately measured, which is of great significance for ensuring the working life of related components and the safe operation of the nuclear reactor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a device for measuring mass flow rate of a fine channel in a reactor in Example 2.

In the figure, 1-high-level container, 2-pipe connection, 3-valve, 4-simulated orifice box, 5-low-level container, 6-quality measuring instrument.

DETAILED DESCRIPTION

The following is a detailed description of a device and method for measuring mass flow rate of a fine channel in a reactor of the present invention in conjunction with the accompanying drawings and embodiments.

Example 1

A device for measuring the mass flow rate of fine channels in a reactor in this embodiment comprises a high-level container 1, a simulated orifice box 4, a low-level container 5 and a mass measuring instrument 6: the liquid in the high-level container 1 flows into the simulated orifice box 4, and flows into the low-level container 5 through the fine through holes on the lower end surface of the simulated orifice box 4 that are used to simulate the fine channels in a nuclear reactor. The mass measuring instrument 6 measures the mass of the liquid received by the low-level container 5.

Example 2

As shown in FIG1 , a device for measuring mass flow rate of a fine channel in a reactor in this embodiment includes a high-level container 1 , a connecting pipe 2 , a valve 3 , a simulated orifice plate box 4 , a low-level container 5 and a mass measuring instrument 6 .

The high-level container 1 is large enough, containing a large amount of liquid, and has a through hole at the lower end; the simulated orifice box 4 is in a box structure as a whole, and the lower end surface of the box is provided with a small through hole for simulating the small channels in the nuclear reactor; the upper end of the connecting pipe 2 is connected to the through hole of the high-level container 1, and the lower end is deep into the box, and the opening/closing of the connecting pipe 2 is controlled by the valve 3; the low-level container 5 is arranged below the simulated orifice box 4 to receive the liquid flowing out through the simulated orifice box 4, specifically, the liquid flowing out of the simulated orifice box 4 through the small through hole flows into the low-level container 5 through another section of the connecting pipe; the mass measuring instrument 6 measures the mass of the liquid received by the low-level container 5.

In this embodiment, the high-level container 1 is filled with enough liquid so that although the liquid flows out through the through hole in a short time (such as 10s), it does not affect the pressure of the liquid surface in the high-level container 1; the liquid contained in the high-level container 1 can be water or other liquids such as oil; the number of small through holes on the lower end surface of the simulated orifice plate box 4 is 1 or more, and the aperture range is 0.5mm to 15mm, such as 0.5mm, 1.5mm, 5.5mm, 9.5mm, 12mm, 15mm; the low-level container 5 can be a measuring cup; the valve 3 can be a solenoid valve; the mass measuring instrument 6 can be an electronic scale.

Example 3

The method for measuring the mass flow rate of a fine channel in a reactor using the measuring device in Example 1 comprises the following steps:

Step S1

Measure the pressure difference △P between the highest liquid level of the high-level container 1 and the lower end surface of the simulated orifice box 4.

In this embodiment, the pressure difference △P can be measured by using a pressure sensor; the pressure difference △P can also be determined by measuring the height difference △h from the highest liquid level of the high-level container 1 to the lower end surface of the simulated orifice box 4, combined with the liquid density ρ and gravitational acceleration g in the high-level container 1.

Step S2

Open the valve 3 to allow the liquid in the high-level container 1 to flow into the simulated orifice box 4 through the connecting pipe 2; and then flow into the low-level container 5 through the fine through holes on the lower end surface of the simulated orifice box 4.

Step S3

After △t time, the mass m of the liquid received by the low-level container 5 during this time period is measured by the mass measuring instrument 6, and the fine through-hole mass flow rate μ under the corresponding pressure difference △P is calculated, μ=m/△t. In this embodiment, △t is a short time period of about 5s to 30s, such as 5s, 10s, 15s, 20s, 25s, 30s, to ensure that the influence of the liquid flowing out during this time period on the pressure difference △P between the highest liquid level of the high-level container 1 and the lower end surface of the simulated orifice box 4 can be ignored.

Step S4

The liquid level of the high-level container 1 is changed, and steps S1 to S3 are repeated to record the mass flow rate μ of the small through hole under different pressure differences △P, and draw a "pressure difference △P-mass flow rate μ of the small through hole" curve.

Step S5

During the operation of a nuclear reactor, the pressure difference of relevant components is monitored and compared with the "pressure difference △P-small through-hole mass flow rate μ" curve to obtain the small pore mass flow rate of the relevant components.

Claims (9)

1. A method for measuring the mass flow rate of a fine pore canal in a reactor is characterized by comprising the following steps: the method adopts fine pore channel mass flow rate measuring equipment in a reactor, the measuring equipment comprises a high-level container (1), a low-level container (5) and a mass measuring instrument (6), liquid in the high-level container (1) flows into the low-level container (5), and the mass measuring instrument (6) measures the mass of the liquid received by the low-level container (5); a simulated pore plate box body (4) is further arranged between the high-level container (1) and the low-level container (5), the simulated pore plate box body (4) is integrally in a box body structure, and a small through hole is formed in the lower end face of the box body; the liquid in the high-level container (1) flows into the simulated orifice plate box body (4) firstly, and flows into the low-level container (5) through the tiny through holes on the lower end surface of the simulated orifice plate box body (4);

the method for measuring the mass flow rate of the fine pore canal in the reactor comprises the following steps:

Step S1, measuring the pressure difference delta P between the highest liquid level of the high-level container (1) and the lower end surface of the simulated orifice plate box body (4);

S2, enabling the liquid in the high-level container (1) to flow into the simulated orifice plate box body (4), and further enabling the liquid to flow into the low-level container (5) through a small through hole on the lower end surface of the simulated orifice plate box body (4);

Step S3, after the Δt time, measuring the mass m of the liquid contained in the low-level container (5) in the period of time by a mass measuring instrument (6), and calculating the fine through hole mass flow rate μ, μ=m/Δtat the corresponding pressure difference ΔP;

Step S4, changing the liquid level of the high-level container (1), repeating the steps S1 to S3, recording the mass flow rate mu of the small through holes under different pressure differences delta P, and drawing a curve of the pressure difference delta P-the mass flow rate mu of the small through holes;

And S5, during the operation process of the nuclear reactor, the pressure difference of the related components is monitored, and the small aperture mass flow rate of the related components is obtained by contrasting the curve of the pressure difference delta P, namely the small through hole mass flow rate mu.

2. A method for measuring the mass flow rate of a fine cell in a reactor according to claim 1, wherein: the reactor internal fine pore channel mass flow rate measuring equipment further comprises a connecting pipe (2), wherein a through hole is formed in the lower end of the high-level container (1), the upper end of the connecting pipe (2) is connected with the through hole of the high-level container (1), and the lower end of the connecting pipe extends into the simulation pore plate box body (4).

3. A method for measuring the mass flow rate of a fine cell in a reactor according to claim 2, wherein: the device for measuring the mass flow rate of the small pore canal in the reactor also comprises a valve (3), and the opening/closing of the connecting pipe (2) is controlled through the valve (3).

4. A method for measuring the mass flow rate of a fine cell in a reactor according to claim 3, wherein: the valve (3) is an electromagnetic valve.

5. A method for measuring the mass flow rate of a fine cell in a reactor according to claim 1, wherein: the mass measuring instrument (6) is an electronic scale.

6. A method for measuring the mass flow rate of a fine cell in a reactor according to claim 1, wherein: the liquid in the high-level container (1) is water or oil.

7. The method for measuring the mass flow rate of a small pore canal in a reactor according to claim 1, wherein the method comprises the following steps: in step S1, a pressure sensor is used to measure the differential pressure Δp.

8. The method for measuring the mass flow rate of a small pore canal in a reactor according to claim 1, wherein the method comprises the following steps: in the step S1, the pressure difference delta P is determined by measuring the height difference delta h from the highest liquid level of the high-level container (1) to the lower end surface of the simulated orifice plate box body (4) and combining the liquid density rho and the gravity acceleration g in the high-level container (1).

9. The method for measuring the mass flow rate of a small pore canal in a reactor according to claim 1, wherein the method comprises the following steps: in step S3, Δt has a value of 5S to 30S.