A borax water tank leakage amount continuous monitoring device based on an ultrasonic flowmeter

Abstract

The present application belongs to the technical field of nuclear power monitoring, and particularly relates to a borate water tank leakage continuous monitoring device based on an ultrasonic flowmeter, which comprises a monitoring device interface, an isolation valve, an emergency valve, a pre-set liquid collector, a valve A, a valve B, a flow measurement element B, a flow measurement element A and a post-set liquid collector; the emergency valve, the monitoring device interface, the isolation valve and the pre-set liquid collector are sequentially connected; a pipeline after the pre-set liquid collector is divided into two parallel branches, one of which is connected in series with the valve A and the flow measurement element A, and the other of which is connected in series with the valve B and the flow measurement element B; then the two parallel branches are combined into the post-set liquid collector. The present application collects the unstable leakage flow of the borate solution in the leakage pipe, converts the leaked borate solution into a state of filling the pipeline to pass through the flow measurement element, and measures and collects the leakage flow data in real time, thereby providing guidance for the relationship between the water tank liquid level and the leakage flow and the identification of the position and elevation of the leakage point.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of nuclear power monitoring, and particularly relates to a borate water tank leakage amount continuous monitoring device based on an ultrasonic flowmeter. BACKGROUND

[0002] A concrete steel lining type water tank for storing borate solution is equipped for a nuclear power unit in design, which is based on concrete and has a sealed stainless steel lining laid on the inner surface of the concrete wall. The stainless steel lining is formed by welding a plurality of stainless steel plates into a whole, so as to store the borate solution. In consideration of the possibility of leakage of the steel lining, a leakage guide pipe is installed at the bottom of the water tank, which is used to guide the borate solution leaked between the steel lining and the concrete out, and then the leaked borate solution is discharged to a special pit through the way of connecting a hose to the end of the leakage guide pipe.

[0003] During the use of the water tank, the problem of leakage of the water tank steel lining may occur due to welding defects, corrosion of the steel lining and other reasons. At the same time, since the outside of the water tank steel lining is a concrete structure, the space between the steel lining and the concrete cannot be regularly checked for leakage during the operation of the unit, and personnel cannot enter the inside of the steel lining water tank for leakage checking during the operation of the nuclear power unit. As known, for a determined leakage position and size, the leakage flow has a certain relationship with the water tank liquid level height, the change of the leakage flow can be monitored during the adjustment of the water tank liquid level, the position elevation of the leakage point is identified, so as to improve the efficiency of subsequent leakage checking. However, since the leakage amount is usually unstable and fluctuates within a certain range, the general flowmeter cannot accurately measure the flow.

[0004] Therefore, it is necessary to provide a borate water tank leakage amount continuous monitoring device based on an ultrasonic flowmeter to solve the problems existing in the prior art. SUMMARY

[0005] The purpose of the present application is to provide a borate water tank leakage amount continuous monitoring device based on an ultrasonic flowmeter, which collects the unstable leakage flow of the borate solution in the leakage guide pipe, and converts the leaked borate solution into a state of filling the pipeline through the flow measurement element, so as to measure and collect the leakage flow data in real time, and provide guidance for studying the relationship between the water tank liquid level and the leakage flow and identifying the position elevation of the leakage point.

[0006] The technical scheme for achieving the purpose of the present application is as follows:

[0007] A borate water tank leakage amount continuous monitoring device based on an ultrasonic flowmeter, which comprises a monitoring device interface, an isolation valve, an emergency valve, a pre-collector, a valve A, a valve B, a flow measurement element B, a flow measurement element A and a post-collector.

[0008] The emergency valve, the monitoring device interface, the isolation valve and the pre-set liquid collector are sequentially connected, the pipeline after the pre-set liquid collector is divided into two parallel branches, one branch is in series connection of the valve A and the flow measurement element A, and the other branch is in series connection of the valve B and the flow measurement element B; the two parallel branches are combined into the post-set liquid collector.

[0009] The flow measurement element A and the flow measurement element B are non-contact ultrasonic flowmeters arranged between the pre-set liquid collector and the post-set liquid collector and fixed on the pipeline through ultrasonic probes coupled with the outer surface of the pipeline.

[0010] The flow measurement element A and the flow measurement element B are arranged in two rows in the same way, and the flow measurement element A and the flow measurement element B are in standby for each other in a way that the valve A and the valve B are opened and closed alternately; if more boric acid solution flows out of the leakage pipe, the valve A and the valve B are opened at the same time, the flow measurement element A and the flow measurement element B are used to measure the leakage flow, and the total leakage flow is the sum of the measured flows of the two rows of flow measurement elements.

[0011] The pre-set liquid collector is arranged upstream of the flow measurement element A and the flow measurement element B, collects the leaked boric acid solution flowing out of the leakage pipe, and sends the collected boric acid solution to the flow measurement element A and the flow measurement element B through the pre-set liquid collector.

[0012] A vent valve is arranged directly above the pre-set liquid collector to avoid the influence of siphon action on the leakage flow.

[0013] An emergency drain pipe where the emergency valve is arranged is arranged between the pre-set liquid collector and the leakage pipe, and when the boric acid tank leakage amount continuous monitoring device fails, the leaked boric acid solution in the leakage pipe is drained to a special pit through the emergency drain pipe connection hose.

[0014] The post-set liquid collector is arranged downstream of the flow measurement element A and the flow measurement element B, collects the boric acid solution passing through the flow measurement element A and the flow measurement element B, and drains the collected boric acid solution to a special pit through the post-set liquid collector.

[0015] A vent pipe is arranged directly above the post-set liquid collector to avoid the influence of siphon action on the leakage flow.

[0016] The post-set liquid collector is connected with a device drainage interface, and the boric acid solution collected by the post-set liquid collector is drained to a special pit through the device drainage interface.

[0017] The beneficial technical effects of the present application are as follows:

[0018] (1) The application provides a borate water tank leakage amount continuous monitoring device based on an ultrasonic flowmeter, realizes long-term stable measurement of the borate water tank leakage amount, provides data for studying the relationship between the leakage flow and the water tank liquid level and identifying the leakage point position elevation, and avoids the influence of siphon action on the leakage flow while realizing the borate solution collection function, so that the long-term stable measurement of the leakage flow is ensured; the emergency liquid discharge pipe realizes that the preposed liquid collector liquid level is higher than the device interface, realizes the emergency discharge of the borate solution in the preposed liquid collector, and avoids borate solution overflow.

[0019] (2) The application uses a non-contact ultrasonic flowmeter, realizes the purpose of borate solution flow measurement through the coupling of the ultrasonic probe and the pipe outer surface and the fixation on the pipe, avoids direct contact with the borate solution, provides two parallel flow measurement elements, the two elements are standby for each other, and the two flow measurement elements are used at the same time when the leakage flow is large, so that the flow measurement range of the device is increased; the liquid collector, the valve and the pipe and other components in contact with the borate solution are made of stainless steel material, so that the corrosion of the borate solution is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 A schematic view of the borate water tank leakage amount continuous monitoring device based on an ultrasonic flowmeter provided by the application. DETAILED DESCRIPTION

[0021] In order for those skilled in the art to better understand the application, the technical solutions in the embodiments of the application will be described clearly and completely below in combination with the drawings in the embodiments of the application. Obviously, the following described embodiments are only part of the embodiments of the application, rather than all. Based on the embodiments described in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0022] As shown in the drawings, Figure 1 The borate water tank leakage amount continuous monitoring device based on an ultrasonic flowmeter provided by the application comprises a monitoring device interface, an isolation valve, an emergency valve, a preposed liquid collector, a valve A, a valve B, a flow measurement element B, a flow measurement element A, a postposed liquid collector, a device drainage interface and a vent valve.

[0023] The emergency valve, the monitoring device interface, the isolation valve and the preposed liquid collector are sequentially connected, the pipe after the preposed liquid collector is divided into two parallel branches, one branch is in series connection of the valve A and the flow measurement element A, and the other branch is in series connection of the valve B and the flow measurement element B; then the two parallel branches are merged into the postposed liquid collector.

[0024] The device is connected with the end of the water tank leakage pipe, and the unstable leakage flow is accurately measured and recorded, and the boric acid solution flowing through the device is discharged to the special pit.

[0025] The flow measurement elements A and B are non-contact ultrasonic flow meters arranged between the front and rear liquid collectors, and are coupled with the outer surface of the pipeline through ultrasonic probes and fixed on the pipeline without contacting the boric acid solution. The pipeline is arranged in a U shape to ensure that the boric acid solution fills the pipeline and flows through the flow measurement elements to realize long-term stable measurement of the boric acid solution flow in the pipeline.

[0026] The flow measurement elements A and B are arranged in two rows in the same way. On the one hand, they can be used as backup for each other by opening and closing valve A and valve B alternately. On the other hand, if the boric acid solution flowing out of the leakage pipe is relatively large, valve A and valve B can be opened at the same time, and the flow measurement elements A and B can be used to measure the leakage flow. At this time, the total leakage flow is the sum of the flow measured by the two flow measurement elements.

[0027] The front liquid collector is arranged upstream of the flow measurement elements A and B, and is used to collect the leaked boric acid solution flowing out of the leakage pipe, and then send the collected boric acid solution to the flow measurement elements A and B through the front liquid collector.

[0028] The vent pipe above the front liquid collector is provided with a vent valve to avoid the influence of siphon effect on the leakage flow. The emergency drain pipe between the front liquid collector and the leakage pipe is provided with an emergency valve to directly discharge the leaked boric acid solution in the leakage pipe to the special pit through the emergency drain pipe and the connecting hose when the boric acid tank leakage monitoring device fails.

[0029] The rear liquid collector is arranged downstream of the flow measurement elements A and B, and is used to collect the boric acid solution flowing through the flow measurement elements A and B.

[0030] The rear liquid collector is connected with a device drain interface, and the boric acid solution collected by the rear liquid collector is discharged to the special pit through the device drain interface.

[0031] The vent pipe above the rear liquid collector is provided to avoid the influence of siphon effect on the leakage flow.

[0032] The front liquid collector, rear liquid collector, valve, pipeline and connecting piece used in the device are made of stainless steel to avoid corrosion of the boric acid solution. The valve is of the ball valve type, which is easy to use and has high reliability.

[0033] The application has been described in detail above with reference to the drawings and embodiments, but the application is not limited to the above-described embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the application. The contents not described in detail in the application can adopt the prior art.

Claims

1. A boric acid water tank leakage continuous monitoring device based on an ultrasonic flow meter, characterized by: A concrete steel-lined water tank used for storing boric acid solution in a nuclear power unit, the device comprising a monitoring device interface, an isolation valve, an emergency valve, a front liquid collector, valve A, valve B, flow measurement element B, flow measurement element A, and a rear liquid collector; The emergency valve, monitoring device interface, isolation valve, and pre-liquid collector are connected in sequence. The pipeline after the pre-liquid collector is divided into two parallel branches, one of which is valve A and flow measurement element A in series, and the other is valve B and flow measurement element B in series. The two parallel branches are then merged into one and connected to the post-liquid collector. The flow measurement element A and the flow measurement element B are non-contact ultrasonic flow meters, which are arranged between the front liquid collector and the rear liquid collector, and are fixed to the pipeline after coupling with the outer surface of the pipeline through an ultrasonic probe; The pipeline is arranged in a U-shape to ensure that the boric acid solution fills the pipeline and flows through the flow measurement element; An air valve is provided just above the front liquid collector to prevent the influence of siphon effect on the leakage flow; An emergency drain pipe with an emergency valve is provided between the front liquid collector and the leakage guide pipe. When the boric acid water tank leakage continuous monitoring device fails, the boric acid solution leaked in the leakage guide pipe is drained to a dedicated pit by connecting the emergency drain pipe to a hose. The post-liquid collector is located downstream of the flow measuring element A and the flow measuring element B, collects the boric acid solution passing through the flow measuring element A and the flow measuring element B, and then discharges the collected boric acid solution into a dedicated pit through the post-liquid collector; An air connection pipe is provided directly above the rear liquid collector to prevent the siphon effect from affecting the leakage flow rate; The flow measuring elements A and flow measuring elements B are arranged in two identical rows, and the flow measuring elements A and flow measuring elements B serve as backup for each other by switching valves A and B, one opening and one closing. If a large amount of boric acid solution flows out of the leakage guide pipe, valves A and B are opened simultaneously to measure the leakage flow rate using flow measuring elements A and flow measuring elements B. At this time, the total leakage flow rate is the sum of the flow rates measured by the two rows of flow measuring elements. The pre-liquid collector is provided upstream of the flow measuring element A and the flow measuring element B, collects the leaked boric acid solution from the leakage guide pipe, and then sends the collected boric acid solution to the flow measuring element A and the flow measuring element B through the pre-liquid collector; The rear liquid collector is connected to a device drainage interface, and the boric acid solution collected by the rear liquid collector is discharged to a dedicated pit through the device drainage interface; Among them, the front liquid collector, rear liquid collector, valves, pipes and connectors are all made of stainless steel to avoid corrosion by boric acid solution, and the valves are ball valve type.

Images