CN210802601U - Measuring system for dynamic liquid level in pipe under steam water working condition - Google Patents

Abstract

The utility model relates to a measuring system for dynamic liquid level in a pipe under steam-water working conditions, which is used for measuring the liquid level in a steam-water mixing pipe; Including the positive-side pressure-inducing subsystem and the negative-side pressure-inducing subsystem, the positive and negative ends of the differential pressure transmitter pass through the positive-side pressure-inducing subsystem and the negative-end pressure-inducing subsystem and the water area and the steam area of the steam-water mixing tube respectively. Connection; instrument control system includes instrument control terminal, pressure transmitter, steam temperature measuring thermocouple and water temperature measuring thermocouple. The pressure transmitter and steam temperature measuring thermocouple are respectively connected to the steam area of the steam-water mixing pipe to measure the water temperature The thermocouple is connected to the water area of the steam-water mixing pipe; the instrument control terminal is respectively electrically connected with the differential pressure transmitter, pressure transmitter, steam temperature thermocouple and water temperature thermocouple, which solves the problem of traditional liquid level gauge. The technical problem of instant and accurate measurement of the liquid level in the pipe cannot be met.

Description

A system for measuring dynamic liquid level in pipes under steam-water conditions

technical field

The utility model relates to the technical field of liquid level measurement, in particular to a dynamic liquid level measurement system in a pipe under high temperature and high pressure steam water conditions.

Background technique

The steam generator in the loop system of the nuclear power plant is used as a high-temperature steam source, and its interior is filled with high-temperature and high-pressure saturated steam and water working medium. The hole flows to the return pipe for recirculation.

Under the condition of high temperature and high pressure steam water, the accurate measurement of the dynamic liquid level in the pipe is of great significance to maintain the stable and efficient operation of the steam generator. Therefore, it is necessary to accurately measure and control the liquid level in the pipe. If the liquid level is too high, the backflow of the separated water will be blocked, and if the liquid level is too low, it will affect the circulation efficiency of the separated water. Under the operating conditions of high temperature and high pressure, the liquid level in the pipe fluctuates violently, and the environmental conditions are relatively harsh; and due to the existence of high temperature and high pressure steam, the liquid level in the pipe is extremely unstable, and there is a large excess space at the steam-water interface.

At present, the traditional liquid level gauge cannot meet the real-time and accurate measurement of the liquid level in the pipe. For example, the mica level gauge cannot work normally under high temperature conditions; the dynamic response of the electric contact level gauge is fast, and the temperature interferes with it little, but the steam The fine droplets mixed in it will affect its measurement; the traditional differential pressure level gauge of the external balance container is difficult to accurately measure the liquid level of the high temperature and high pressure hydraulic fluid with large density changes.

Utility model content

The purpose of the utility model is to provide a measuring system of dynamic liquid level in the pipe under the steam-water working condition, so as to solve the technical problem that the traditional liquid level gauge cannot satisfy the instant and accurate measurement of the liquid level in the pipe.

In order to solve the above problems, the present invention provides a dynamic liquid level measurement system in a pipe under steam-water conditions, which is used to measure the liquid level in a steam-water mixing pipe, and the steam-water mixing pipe includes a steam area and a water area. The system includes:

Differential pressure transmitter;

The pressure introduction system includes a positive pressure introduction subsystem and a negative pressure introduction subsystem, and the positive and negative ends of the differential pressure transmitter are respectively connected with the positive pressure introduction subsystem and the negative pressure introduction subsystem through the positive pressure introduction subsystem and the negative pressure introduction subsystem. The water area and the steam area of the steam-water mixing pipe are connected;

The instrument control system includes an instrument control terminal, a pressure transmitter, a thermocouple for measuring steam temperature and a thermocouple for measuring water temperature, the pressure transmitter and the thermocouple for measuring steam temperature are respectively connected to the steam area, and the The water temperature measuring thermocouple is connected to the water area; the instrument control terminal is respectively electrically connected with the differential pressure transmitter, the pressure transmitter, the steam temperature measuring thermocouple and the water temperature measuring thermocouple.

Preferably, the positive end of the differential pressure transmitter is respectively provided with a positive end stop valve and a positive end blowdown nut, the negative end is respectively provided with a negative end stop valve and a negative end blowdown nut, and the positive end stop valve and the negative end are respectively provided with A balance valve is provided between the shut-off valves.

Preferably, the positive-end pressure-inducing subsystem includes connecting the positive-end lower root valve, the positive-end balance container and the positive-end upper root valve in sequence through the positive-end pressure-inducing pipe, and the upper part of the positive end balance container is also provided with a valve. Positive exhaust valve;

The negative-end pressure-inducing subsystem includes connecting the negative-end lower root valve, the negative-end balance container and the negative-end upper root valve in sequence through the negative-end pressure-inducing pipe, and the upper part of the negative end balance container is also provided with a negative end row. empty valve;

The negative-end pressure-inducing pipe between the negative-end lower root valve and the negative-end balance container is also connected with a water supply pipe, and a water injection valve is arranged on the water supply pipe.

Preferably, a regulating valve is also arranged at the bottom of the steam-water mixing pipe.

Compared with the prior art, the utility model has the following technical effects:

In the utility model, the positive and negative ends of the differential pressure transmitter are respectively connected with the water area and the steam area of the steam-water mixing tube through the positive-end pressure-inducing subsystem and the negative-end pressure-inducing subsystem. Based on the incompressibility of water, The pressure of the measuring point can be quickly transmitted to both ends of the differential pressure transmitter, which ensures the immediacy and continuity of the liquid level measurement. Differential pressure, temperature and pressure signals are converted into electrical signals and transmitted to the instrument control system to realize remote monitoring and data processing and correction, and to continuously and accurately measure the dynamically changing liquid level. The utility model has the advantages of simple principle, convenient operation, accurate and continuous measurement of the liquid level in the pipe under the working condition of high temperature and high pressure steam water, fast dynamic response, long working life and minimal environmental influence.

When the measuring system provided by the utility model is put into use, the air in the pressure-inducing pipe is firstly drained, so as to avoid the measurement fluctuation caused by the compressibility of the air in the pressure-inducing pipe. Where the steam pressure is measured at the negative end, the negative end balance container reduces the influence of steam condensation and fluctuation on the pressure, and the balance containers at both ends act as condensation tanks, which not only protects the differential pressure transmitter from high temperature working fluids In addition, the pressure-inducing tube is divided into two sections, cold and hot, and the density correction based on temperature and pressure is performed on the working fluid of the two sections respectively, so as to improve the accuracy of differential pressure measurement.

Of course, any product implementing the present invention does not necessarily need to simultaneously achieve all of the above-mentioned advantages.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained from these drawings without creative effort. In the attached picture:

FIG. 1 is a schematic structural diagram of a system for measuring dynamic liquid level in a pipe under a steam-water working condition provided by a preferred embodiment of the present invention.

Detailed ways

The following will describe in detail a system for measuring the dynamic liquid level in the pipe under the steam-water condition provided by the present invention with reference to FIG. 1 . However, the protection scope of the present invention is not limited to the following examples, and those skilled in the art can modify and refine the present invention within the scope of not changing the spirit and content of the present invention.

Please refer to FIG. 1 , the present invention provides a system for measuring the dynamic liquid level in the pipe under the steam-water working condition, for measuring the liquid level in the steam-water mixing pipe 3, which includes a steam area 31 and a water area in the steam-water mixing pipe 3 32 (the steam is located at the upper part of the steam-water mixing pipe 3, and the water is located at the lower part of the steam-water mixing pipe 3, so the steam and water are divided into a steam area 31 and a water area 32); the measurement system includes:

Differential pressure transmitter 1;

The pressure-inducing system 2 includes a positive-end pressure-inducing subsystem 22 and a negative-end pressure-inducing subsystem 21, and the positive and negative ends of the differential pressure transmitter 1 pass through the positive-end pressure-inducing subsystem 22 and the negative end respectively. The pressure-inducing subsystem 21 is connected with the water area and the steam area of the steam-water mixing pipe 3;

The instrument control system 4 includes an instrument control terminal 41, a pressure transmitter 43, a steam temperature measurement thermocouple 44 and a water temperature measurement thermocouple 42, and the pressure transmitter 43 and the steam temperature measurement thermocouple 44 are respectively connected to the The steam area 31 of the steam-water mixing pipe 3, the water temperature measuring thermocouple 42 is connected to the water area 32 of the steam-water mixing pipe 3; the instrument control terminal 41 is respectively connected with the differential pressure transmitter 1, the pressure variable The transmitter 43, the steam temperature measuring thermocouple 44 and the water temperature measuring thermocouple 42 are electrically connected.

In this embodiment, the positive end of the differential pressure transmitter 1 is respectively provided with a positive end stop valve 13 and a positive end blowdown nut 14, and the negative end is respectively provided with a negative end stop valve 11 and a negative end blowdown nut 15. A balance valve 12 is provided between the positive end stop valve 13 and the negative end stop valve 11 .

The positive-end pressure-inducing subsystem 22 includes a positive-end lower root valve 221, a positive-end balance container 223 and a positive-end upper-root valve 225 connected in sequence through the positive-end pressure-inducing pipe 222, and the positive-end lower root valve 221 is cut off from the positive end. The valve 13 is connected, and the root valve 225 on the positive end is connected with the water area 32; the upper part of the positive end balance container 223 is also provided with a positive end emptying valve 224;

The negative-end pressure-inducing subsystem 21 includes a negative-end lower-root valve 211, a negative-end balance container 215, and a negative-end upper-root valve 217 that are sequentially connected to the negative-end lower-root valve 211 through the negative-end pressure-inducing pipe 214, and the negative-end lower root valve 211 and the negative end. The stop valve 11 is connected, and the root valve 217 on the negative end is connected with the steam area 31; the upper part of the negative end balance container 215 is also provided with a negative end emptying valve 216;

The negative-end pressure-inducing pipe 214 between the negative-end lower root valve 211 and the negative-end balance container 215 is also connected to a water supply pipe 212 , and a water injection valve 213 is arranged on the water supply pipe 212 .

A regulating valve 33 is also provided at the bottom of the steam-water mixing pipe 3 .

Further, the steam-water mixing pipe 3 is provided with a steam port corresponding to the steam area 31 and a water port corresponding to the water area 32, the root valve 225 on the positive end is connected with the water port, and the root valve 217 on the negative end is connected with the steam port. connect.

All the above valves are electrically connected to the instrument control terminal.

The utility model also provides a measurement method of an implemented measurement system, comprising the following steps:

1. System emptying

Under the condition of normal temperature and pressure, that is, before the high temperature and high pressure steam water working condition is established, open the balance valve, the positive end stop valve 13, the negative end stop valve 11, the positive end lower root valve 221, and the negative end lower root valve 211, close the positive end The root valve 225 on the end and the root valve 217 on the negative end, open the positive end emptying valve 224 and the negative end emptying valve 216, and unscrew the positive end blowdown nut 14 and the negative end blowdown nut 15 respectively; open the water injection valve 213 to discharge the positive end. The residual sewage, air bubbles and small particles of impurities in the end pressure-inducing tube 222 and the negative-end pressure-inducing tube 214 ensure the cleanliness of the entire measurement system;

2. Initialization

Tighten the positive drain nut 14 and the negative drain nut 15, then inject water into the pressure pipe system through the water supply pipe 212, and control the water supply pressure by adjusting the water injection valve 213. After the water is injected to the positive end emptying valve 224, the water is turned off. Positive end lower root valve 221; continue to inject water to the negative end emptying valve 216, close the water injection valve 213 to stop water supply; close the balance valve, open the positive end lower root valve 221, and then close the positive end emptying valve 224 and the negative end End emptying valve 216; open the upper root valve 225 of the positive end and the upper root valve 217 of the negative end, the differential pressure transmitter 1 sends the real-time display ΔP _H to the instrument control terminal 41, and the instrument control terminal 41 receives the data Then, calculate the vertical height difference H between the positive end measurement point and the negative end measurement point through the preset built-in formula:

where:

ρ ₀ — water density under site ambient temperature and pressure;

g—— is the local gravitational acceleration;

Complete the measurement system initialization;

3. Test

After the high temperature and high pressure steam water working condition is established, the instrument control terminal 41 receives the pressure transmitter 43 , the water temperature measuring thermocouple 42 , and the steam temperature measuring thermocouple 44 in real time to measure the pressure P ₁ and the water temperature T ₁ in the steam water mixing pipe 3 . , the steam temperature T ₂ ; after the instrument control terminal 41 obtains the temperature and pressure parameters, the water density ρ _water and the steam density ρ _steam in the steam-water mixing tube 3 under the corresponding working conditions can be obtained in real time according to the built-in associated water physical property function. At this time, The pressure difference between the positive end and the positive end measuring point of differential pressure transmitter 1 is:

P ₁ -P ₁ ^* =ρ ₀ gh ₁ (2)

where:

P ₁ —— differential pressure transmitter 1 positive end pressure;

P ₁ ^* ——the pressure of the positive end measuring point;

h ₁ ——the vertical distance height difference between the positive end and the positive end measuring point of differential pressure transmitter 1;

The pressure difference between the negative end of the differential pressure transmitter 1 and the negative end measuring point is:

where:

P ₂ —— Negative end pressure of differential pressure transmitter 1;

——负端测点压力；

——Pressure of negative terminal measuring point;

h ₂ ——the vertical distance height difference between the negative end of differential pressure transmitter 1 and the negative end measuring point;

The pressure difference between the positive end point and the negative end point is:

The indication of differential pressure transmitter 1 is:

ΔP=P ₁ -P ₂ (5)

The liquid level of the soda-water mixing pipe 3 is obtained by the simultaneous equations (1)-(5):

The instrument control terminal 41 performs real-time processing of the acquired differential pressure data and correction of temperature and pressure according to the built-in formula, and obtains liquid level data and displays it for monitoring. Real-time accurate monitoring of dynamic liquid level in pipes.

The above disclosure is only a specific embodiment of the present application, but the present application is not limited thereto, and any changes that can be conceived by those skilled in the art should fall within the protection scope of the present application.

Claims (4)

1. The utility model provides a measurement system of intraductal dynamic liquid level under steam and water operating mode for measure the liquid level in the steam-water mixing pipe, including steam region and water region in the steam-water mixing pipe, its characterized in that, measurement system includes:

a differential pressure transmitter;

the pressure guiding system comprises a positive end pressure guiding subsystem and a negative end pressure guiding subsystem, and the positive end and the negative end of the differential pressure transmitter are respectively connected with a water area and a steam area of the steam-water mixing pipe through the positive end pressure guiding subsystem and the negative end pressure guiding subsystem;

the steam temperature thermocouple is connected with the steam area, and the water temperature thermocouple is connected with the water area; and the instrument control terminal is respectively and electrically connected with the differential pressure transmitter, the steam temperature measuring thermocouple and the water temperature measuring thermocouple.

2. The system for measuring the dynamic liquid level in the pipe under the steam water working condition as claimed in claim 1, wherein the positive end of the differential pressure transmitter is respectively provided with a positive end stop valve and a positive end drain nut, the negative end of the differential pressure transmitter is respectively provided with a negative end stop valve and a negative end drain nut, and a balance valve is arranged between the positive end stop valve and the negative end stop valve.

3. The system for measuring the dynamic liquid level in the pipe under the steam water working condition as claimed in claim 2, wherein the positive end pressure leading subsystem comprises a positive end lower root valve, a positive end balancing container and a positive end upper root valve which are sequentially connected through a positive end pressure leading pipe, and a positive end emptying valve is further arranged at the upper part of the positive end balancing container;

the negative end pressure leading subsystem comprises a negative end lower root valve, a negative end balancing container and a negative end upper root valve which are sequentially connected through a negative end pressure leading pipe, and a negative end emptying valve is further arranged at the upper part of the negative end balancing container;

the negative end pressure leading pipe between the negative end lower root valve and the negative end balancing container is also connected with a water supply pipe, and a water injection valve is arranged on the water supply pipe.

4. The system for measuring the dynamic liquid level in the pipe under the steam water working condition as claimed in claim 1, wherein the bottom of the steam-water mixing pipe is further provided with a regulating valve.

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