Flow measurement system based on cooling water medium of nuclear power plant

Abstract

The utility model discloses a flow measuring system based on a cooling water medium of a nuclear power plant, which comprises a flow measuring device arranged at a cooling water position of the nuclear power plant, the flow measuring device comprises a measuring tube and a differential pressure transmitter unit, the measuring tube comprises a measuring tube body, a porous balance pore plate and two sampling tubes, the porous balance pore plate is arranged in the center of the interior of the measuring tube body, the two sampling tubes are respectively arranged at the left end and the right end of the measuring tube body, one end of each sampling tube is communicated to the interior of the measuring tube body, and the other end of each sampling tube is respectively connected with the differential pressure transmitter unit; and the signal processing box is connected with the differential pressure transmitter unit and is used for receiving and processing the cooling water information sent by the differential pressure transmitter unit. The multi-hole balance pore plate can bear washing of a cooling medium, system foreign matter cannot be formed, and measurement reliability is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of nuclear power plant cooling water measurement, in particular to a flow measurement system based on nuclear power plant cooling water medium. Background Art

[0002] Some important process systems in nuclear power plants require cooling water for cooling, so it is necessary to measure the cooling water in order to know whether the cooling water of these systems is operating normally.

[0003] The current monitoring of cooling water flow usually adopts a target flow switch with a pipe section structure. The measurement principle is that when the fluid passes through the flow switch in a specified direction, the measuring baffle will be displaced according to the size of the flow, and the displacement is in a state of equilibrium with the spring force. Each determined flow corresponds to a balanced position. When the flow exceeds or falls below the preset point, the micro switch will act and output a switch signal to realize the flow alarm. The measurement accuracy of this type of flow switch is highly dependent on the position when the displacement and the spring force are in a state of equilibrium.

[0004] The flow switch target used in the flow measurement system is in long-term motion and under stress. During operation, the water flow in the pipeline keeps changing, and the spring keeps swinging with the rake. During long-term operation, the spring is prone to fatigue, causing spring wear or breakage, and introducing the risk of foreign matter into the system. In addition, the target flowmeter's target baffle is prone to loosening under long-term flushing. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a flow measurement system based on cooling water medium of a nuclear power plant.

[0006] The utility model solves the technical problem by adopting a technical solution: providing a flow measurement system based on cooling water medium of a nuclear power plant, comprising:

[0007] A flow measurement device arranged at a cooling water position of a nuclear power plant, the flow measurement device comprising a measuring tube and a differential pressure transmitter unit, the measuring tube comprising a measuring tube body, a multi-hole balancing orifice plate and two sampling tubes, the multi-hole balancing orifice plate being arranged at the center of the interior of the measuring tube body, one end of each of the sampling tubes being connected to the interior of the measuring tube body, and the other end of each of the sampling tubes being connected to the differential pressure transmitter unit respectively;

[0008] A signal processing box is connected to the differential pressure transmitter unit, receives the cooling water information sent by the differential pressure transmitter unit and processes the cooling water information.

[0009] Furthermore, the differential pressure transmitter unit includes a sampling isolation valve, a five-valve group, and a differential pressure transmitter. The sampling isolation valve is connected to the sampling tube on the measuring tube, the five-valve group is respectively connected to the sampling isolation valve and the differential pressure transmitter, and the differential pressure transmitter is connected to the signal processing box.

[0010] Furthermore, the measuring tube and the differential pressure transmitter unit are integrated or detachably arranged.

[0011] Furthermore, four circular through holes are evenly distributed on the porous balancing plate.

[0012] Furthermore, the thickness of the porous balancing plate is 4 mm.

[0013] Furthermore, the signal processing box is provided with a display unit, and the display unit is used to display the cooling water information.

[0014] Furthermore, the signal processing box includes: a signal conversion unit, and the signal conversion unit is provided with two signal outputs.

[0015] Furthermore, it also includes: a control system connected to the signal processing box, receiving the processing result sent by the signal processing box and controlling the external device according to the processing result.

[0016] Furthermore, the control system is a DCS control system.

[0017] Furthermore, the DCS control system uses a direct current voltage of 24V.

[0018] The implementation of this utility model has the following beneficial effects:

[0019] The utility model provides a flow measurement device in a flow measurement system based on a nuclear power plant cooling water medium, comprising a measuring tube and a differential pressure transmitter unit. The measuring tube adopts a porous balancing orifice plate to withstand the scouring of the cooling medium and will not form foreign matter in the system. The porous balancing plate is used to balance and adjust the fluid in the measuring tube so that the fluid forms an approximately rational fluid, which facilitates the differential pressure transmitter unit to obtain a differential pressure signal from the sampling tube, and then conveniently calculates the volume flow and mass flow according to the Bernoulli equation, thereby improving the measurement reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0021] Figure 1 This is a schematic diagram of the current nuclear power plant cooling water flow measurement;

[0022] Figure 2 A front view of a flow measurement device provided by an embodiment of the utility model;

[0023] Figure 3 A side view of a flow measurement device provided by an embodiment of the utility model;

[0024] Figure 4 A schematic diagram of the measurement principle of a flow measurement device provided in one embodiment of the utility model;

[0025] Figure 5 A schematic diagram of a flow measurement system based on cooling water medium of a nuclear power plant provided by an embodiment of the utility model;

[0026] Among them, 10, flow test equipment; 110, measuring tube; 1101, measuring tube body; 1102, multi-hole balancing orifice plate; 1103, sampling tube; 120, differential pressure transmitter unit; 1201, sampling isolation valve; 1202, five-valve group; 1203, differential pressure transmitter; 20, signal processing box; 30, control system. DETAILED DESCRIPTION

[0027] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "up", "down", "left", "right", "longitudinal", "horizontal", "vertical", "horizontal", "top", "bottom", "inside", "outside", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, are constructed and operated in a specific direction, and are only for the convenience of describing the present technical solution, rather than indicating that the device or element referred to must have a specific direction, and therefore cannot be understood as a limitation to the present invention.

[0028] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. When an element is referred to as being "on" or "under" another element, the element can be "directly" or "indirectly" located on the other element, or there may be one or more intermediate elements. The terms "first", "second", "third", etc. are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", "third", etc. can explicitly or implicitly include one or more of the features. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.

[0029] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details that hinder the description of the present invention.

[0030] Some important process systems in nuclear power plants require cooling water for cooling, so it is necessary to measure the cooling water in order to know whether the cooling water of these systems is operating normally.

[0031] like Figure 1 As shown, the current monitoring of cooling water flow usually adopts a target flow switch with a pipe segment structure. The measurement principle is that when the fluid passes through the flow switch in a specified direction, the measuring baffle is displaced according to the size of the flow, and the displacement is in a state of equilibrium with the spring force. Each determined flow corresponds to a balanced position. When the flow exceeds or falls below the preset point, the micro switch will operate and output a switch signal to realize the flow alarm. The measurement accuracy of this type of flow switch is highly dependent on the position when the displacement and the spring force are in a state of equilibrium.

[0032] The flow switch target used in the flow measurement system is in long-term motion and under stress. During operation, the water flow in the pipeline keeps changing, and the spring keeps swinging with the rake. During long-term operation, the spring is prone to fatigue, causing spring wear or breakage, and introducing the risk of foreign matter into the system. In addition, the target flowmeter's target baffle is prone to loosening under long-term flushing.

[0033] like Figure 2 and Figure 3 As shown, the embodiment of the utility model provides a flow measurement system based on cooling water medium of a nuclear power plant, comprising:

[0034] A flow measurement device 10 is provided at a cooling water position of a nuclear power plant, the flow measurement device 10 comprises a measuring tube 110 and a differential pressure transmitter unit 120, the measuring tube 110 comprises a measuring tube body 1101, a multi-hole balancing orifice plate 1102 and two sampling tubes 1103, the multi-hole balancing orifice plate 1102 is provided at the inner center of the measuring tube body 1101, one end of each sampling tube 1103 is connected to the inner part of the measuring tube body 1101, and the other end of each sampling tube 1103 is respectively connected to the differential pressure transmitter unit 120;

[0035] The signal processing box 20 is connected to the differential pressure transmitter unit 120, receives the cooling water information sent by the differential pressure transmitter unit 120 and processes the cooling water information.

[0036] Specifically, in this embodiment, the flow measurement device 10 is set at the cooling water position of the nuclear power plant for measurement. Since the target flow switch currently used in nuclear power plants is prone to cause foreign matter in the system to affect the measurement results when measuring cooling water, and there are certain requirements for the installation position of the straight pipe section required for measurement. Different from the target flow switch, the measuring tube 110 in this embodiment adopts a porous balancing orifice plate 1102. Among them, the porous balancing orifice plate 1102 is a porous steel disc throttling rectifier, which is welded to the inner center of the measuring tube body 1101 (that is, the central section of the pipe of the measuring tube body 1101). The size and distribution of each disc function through hole on the porous balancing orifice plate 1102 are customized based on unique formulas and test data.

[0037] At positions with the same spacing on both sides of the porous balancing orifice plate 1102, holes are opened in the measuring tube body 1101 and sampling tubes 1103 are welded thereto. One end of the sampling tube 1103 is connected to the interior of the measuring tube body 1101 through a through hole to measure the fluid flowing in the measuring tube body 1101; the other end of the sampling tube is connected to the differential pressure transmitter unit 120 to facilitate sending the pressure difference of the fluid to the differential pressure transmitter unit 120.

[0038] The measurement principle of the multi-hole balanced plate is as follows Figure 4 As shown, when a fluid (cooling water) with a certain flow rate flows through the disc function through-holes on the porous balancing orifice plate 1102, the fluid will be balanced and adjusted, and the vortex will be minimized, which will play a throttling role on the fluid and form an approximately rational fluid. A pressure difference is formed on both sides of the porous balancing orifice plate 1102 (between upstream and downstream). One of the sampling tubes 1103 takes the upstream P H , another sampling tube 1103 takes the downstream P L The differential pressure transmitter unit 120 obtains a differential pressure signal from the two sampling tubes 1103, and then calculates the differential pressure signal according to the Bernoulli equation to obtain the volume flow rate and mass flow rate (cooling water information).

[0039] The differential pressure transmitter unit 120 sends the cooling water information to the signal processing box 20, and the signal processing box 20 displays the calculated cooling water information. In addition, the signal processing box 20 also displays the flow alarm setting value and sends a switch alarm signal indicating whether the actual flow is low to the remote operation operator.

[0040] Furthermore, the number of circular through holes (disc function through holes) on the porous balancing plate 1102 can be determined according to actual needs. Figure 3 As shown, four circular through holes are evenly distributed on the porous balance plate 1102.

[0041] Furthermore, since the porous balancing orifice plate 1102 is disposed in the center of the measuring tube body 1101, the thickness of the porous balancing orifice plate 1102 should be adapted to the measuring tube body 1101, and the thickness of the porous balancing orifice plate 1102 can be determined according to actual needs. In one embodiment of the present invention, the thickness of the porous balancing orifice plate 1102 is 4 mm.

[0042] like Figure 2 and Figure 3 As shown, in one embodiment of the utility model, the differential pressure transmitter unit 120 includes a sampling isolation valve 1201, a five-valve group 1202, and a differential pressure transmitter 1203. The sampling isolation valve 1201 is connected to the sampling tube 1103 on the measuring tube 110, the five-valve group 1202 is respectively connected to the sampling isolation valve 1201 and the differential pressure transmitter 1203, and the differential pressure transmitter 1203 is connected to the signal processing box 20.

[0043] Specifically, the differential pressure transmitter unit 120 is composed of a sampling isolation valve 1201, a five-valve group 1202, and a differential pressure transmitter 1203. The sampling isolation valve 1201 and the differential pressure transmitter 1203 are installed on the five-valve group 1202 for easy installation and maintenance. The sampling isolation valve 1201 is connected to the sampling tube 1103 on the measuring tube 110. The fluid passes through the porous balancing orifice plate 1102, and a pressure difference is formed between the upstream and downstream. The two sampling tubes 1103 take the upstream and downstream respectively, and give them to the differential pressure transmitter 1203 through the sampling isolation valve 1201.

[0044] like Figure 5 As shown, in one embodiment of the present invention, the measuring tube 110 and the differential pressure transmitter unit 120 are integrated or detachably arranged. Specifically, the actual arrangement between the measuring tube 110 and the differential pressure transmitter unit 120 can be determined according to the application scenario to improve the application efficiency. For example, a sampling line can be arranged between the measuring tube 110 and the differential pressure transmitter unit 120 according to the on-site space.

[0045] In one embodiment of the utility model, the signal processing box 20 is provided with a display unit, and the display unit is used to display cooling water information (cooling water flow data). Specifically, a glass observation window is provided on the signal processing box 20, and the display unit includes but is not limited to a touch screen, for example, a touch screen is used for human-computer interaction, and the operator can view cooling water information such as cooling water volume flow data by clicking on the touch screen, which is quick and convenient. In addition, the signal processing box 20 can have functions such as on-site real-time numerical display, alarm threshold display, and alarm transmission.

[0046] like Figure 5 As shown, in one embodiment of the present invention, the signal processing box 20 includes: a signal conversion unit, and the signal conversion unit is provided with two signal outputs.

[0047] Specifically, the signal processing box 20 is provided with a wireless remote transmission module antenna, which has a remote transmission function. The signal conversion unit is provided with two signal outputs, one of which compares the flow value of the cooling water with the alarm value preset in the signal processing box 20 to trigger the dry node action, and the other can output a 4-20mA signal. In addition, the signal processing box 20 also has a wireless transmission interface to control the 4-20mA signal of multiple groups of flow meters in the signal processing box 20 to access the analog wireless transmission card, and can send wireless signals for digital secondary development of mobile phone apps or web pages to realize functions such as trend display and abnormal alarm judgment push.

[0048] like Figure 5 As shown, in one embodiment of the present invention, it also includes: a control system 30 connected to the signal processing box 20, receiving the processing results sent by the signal processing box 20 and controlling the external device according to the processing results.

[0049] Specifically, the control system 30 can control external devices according to the processing results sent by the signal processing box 20, realize secondary development functions such as back-end digital inspection, and thus improve the practicality of the system.

[0050] In this embodiment, the control system 30 is a DCS control system, wherein the DCS control system may use a DC 24V voltage and may be used to receive a low flow alarm signal from the site.

[0051] Different from the current nuclear power plant cooling water measurement using target flow switches, which have the disadvantages of easy scouring and falling off to form system foreign bodies, the inability to meet the installation position of the long straight pipe section required for measurement, poor accuracy and inability to display real-time flow on site, the utility model embodiment provides a flow measurement system based on the cooling water medium of a nuclear power plant, including a flow measurement device and a signal processing box, the flow measurement device includes a measuring tube and a differential pressure transmitter unit, the measuring tube adopts a porous balance orifice plate to withstand the scouring of the cooling medium, will not form system foreign bodies, and uses a porous balance plate to balance and adjust the fluid in the measuring tube, so that the fluid forms an approximate rational fluid, which facilitates the differential pressure transmitter unit to obtain a differential pressure signal from the sampling tube, and then conveniently calculates the volume flow and mass flow according to the Bernoulli equation, thereby improving the measurement reliability. In addition, the flow measurement device can be used in an ultra-short flow field, is not restricted by the on-site pipeline space and flow field, and requires a very small distance between the front and rear straight pipe sections.

[0052] In addition, the signal processing box has remote transmission function and wireless transmission interface, and has on-site real-time numerical display, alarm threshold display and alarm transmission functions. Combined with the control system, it can carry out secondary development such as back-end digital inspection. It can perform routine calibration of the differential pressure transmitter unit in the standard laboratory of the nuclear power plant, with low operation and maintenance costs, thereby improving the measurement reliability of the system as a whole.

[0053] The above embodiments only express the preferred implementation modes of the present utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present utility model. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present utility model, and several deformations and improvements can be made, which all belong to the protection scope of the present utility model. Therefore, all equivalent changes and modifications made to the scope of the claims of the present utility model should belong to the scope covered by the claims of the present utility model.

Claims

1. A flow measurement system based on cooling water medium of a nuclear power plant, characterized in that: include: A flow measurement device arranged at a cooling water position of a nuclear power plant, the flow measurement device comprising a measuring tube and a differential pressure transmitter unit, the measuring tube comprising a measuring tube body, a multi-hole balancing orifice plate and two sampling tubes, the multi-hole balancing orifice plate being arranged at the center of the interior of the measuring tube body, one end of each of the sampling tubes being connected to the interior of the measuring tube body, and the other end of each of the sampling tubes being connected to the differential pressure transmitter unit respectively; A signal processing box is connected to the differential pressure transmitter unit, receives the cooling water information sent by the differential pressure transmitter unit and processes the cooling water information.

2. The flow measurement system according to claim 1, characterized in that: The differential pressure transmitter unit includes a sampling isolation valve, a five-valve group, and a differential pressure transmitter. The sampling isolation valve is connected to the sampling tube on the measuring tube, the five-valve group is respectively connected to the sampling isolation valve and the differential pressure transmitter, and the differential pressure transmitter is connected to the signal processing box.

3. The flow measurement system according to claim 1, characterized in that: The measuring tube and the differential pressure transmitter unit are integrated or detachably arranged.

4. The flow measurement system according to claim 1, characterized in that: Four circular through holes are evenly distributed on the porous balance plate.

5. The flow measurement system according to claim 1, characterized in that: The thickness of the porous balance plate is 4 mm.

6. The flow measurement system according to claim 1, characterized in that: The signal processing box is provided with a display unit, and the display unit is used to display the cooling water information.

7. The flow measurement system according to claim 1, characterized in that: The signal processing box comprises: a signal conversion unit, and the signal conversion unit is provided with two signal outputs.

8. The flow measurement system according to claim 1, characterized in that: Also includes: A control system connected to the signal processing box, receiving the processing results sent by the signal processing box and controlling the external device according to the processing results.

9. The flow measurement system according to claim 8, characterized in that: The control system is a DCS control system.

10. The flow measurement system according to claim 9, characterized in that: The DCS control system uses a direct current voltage of 24V.

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