Heater flow detection device for ventilation system of nuclear power plant
By using a flow detection device combined with a pyrolysis flowmeter and mount in the ventilation system of a nuclear power plant, the problems of high failure rate of the baffle flow switch and inaccurate measurement are solved, effectively monitoring and protection of the dry burning risk of the heater is achieved, and the stability and measurement accuracy of the system are improved.
Patent Information
- Application Number
- CN202421845003.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-31
- Publication Date
- 2025-04-29
- Estimated Expiration
- 2034-07-31
AI Technical Summary
The failure rate of the baffle flow switch of the heater of the ventilation system of the existing nuclear power plant is high, the measurement is inaccurate and the calibration cannot be achieved, resulting in the failure of the heater protection function and affecting the stable operation of the ventilation system.
A heater flow detection device for ventilation system of nuclear power plants is designed, using a pyrolysis flowmeter and mount to judge the flow rate in the air duct through the fluid temperature, real-time monitoring and protection of the dry burning risk of the heater is achieved.
It improves the stability and measurement accuracy of heater flow detection, can effectively prevent the heater from burning and reduce the failure rate, and the device can be calibrated and tested in China, making it more convenient and cost-effective.
Smart Images
Figure CN222812419U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of nuclear power, in particular to a flow detection device for a heater of a ventilation system of a nuclear power plant. Background Art
[0002] In the ventilation system of a nuclear power plant, the heater needs to be designed with a protection function to prevent dry burning of the heater in the absence of ventilation, which can burn the heater body and cause equipment damage. In addition, it is also to avoid the risk of fire caused by high temperature. The protection design of the heater in the ventilation system of a nuclear power plant is generally divided into flow protection and temperature protection. The flow protection uses a switch to determine whether the flow in the air duct is lower than the design value and gives an alarm to control the start and stop of the heater.
[0003] At present, a nuclear power plant uses F62AA-9C and F262KDH-01C baffle flow switches. The wind pressure in the air duct acts on the baffle, and the displacement of the baffle acts on the micro switch through the transmission rod. When the wind speed is greater than the set value, the micro switch output is reset, indicating that the wind speed is not low; when the wind speed is lower than the set value, the baffle returns to a state close to the initial state under the action of the reset spring, and the micro switch output is set, indicating that the wind speed is low.
[0004] During the application process, the following problems were found in the flapper flow switch: (1) The product failure rate is high. According to SAP data, the flow switch has been replaced 26 times. 8 times were due to flap breakage (installation time ranged from 53D to 2592D), and 18 times were due to set value drift. (2) Inaccurate measurement. (3) Unable to calibrate: There is no domestic organization that can calibrate the set value of this type of instrument.
[0005] Problems (1) and (2) result in the inability to effectively protect the heater, which in turn affects the stable operation of the ventilation system of the nuclear power plant. Problem (3) makes the baffle flow switch inconvenient to calibrate, poor in convenience, and high in cost. Utility Model Content
[0006] The technical problem to be solved by the utility model is to provide a flow detection device for a heater of a ventilation system of a nuclear power plant.
[0007] The utility model solves the technical problem by adopting a technical solution: constructing a flow detection device for a heater of a ventilation system of a nuclear power plant, comprising a mounting seat mounted on an air duct and communicating with the inner cavity of the air duct, and a pyroelectric flowmeter detachably mounted on the mounting seat; the pyroelectric flowmeter comprises a body, a mounting portion connected to the body, and a probe connected to the body; the outer periphery of the mounting portion is provided with an external thread;
[0008] The mounting seat includes at least one nut seat, and the inner cavity of the nut seat is provided with an internal thread that matches the external thread; or, the mounting seat includes a first mounting tube and a second mounting tube, the first mounting tube is fixed on the air duct, and the inner cavity of the first mounting tube is connected to the inner cavity of the air duct, the outer diameter of the second mounting tube is smaller than the inner diameter of the first mounting tube, the inner wall surface of the second mounting tube is provided with an internal thread that matches the external thread, and the first mounting tube is provided with a through hole along the height direction for a fastener to pass through to tighten the outer side surface of the second mounting tube.
[0009] In some embodiments, the number of the nut seats is two, the two nut seats are axially stacked together, and the two nut seats are coaxially arranged.
[0010] In some embodiments, the two nut seats are fixed by welding.
[0011] In some embodiments, the circumferential outer side surface of the second mounting tube is provided with a plurality of limiting grooves along the height direction for the ends of the fastener to be inserted therein.
[0012] In some embodiments, the fastener comprises a bolt, a screw, or a latch.
[0013] In some embodiments, a convex portion extends outwardly from the circumferential outer surface of the upper end of the second mounting tube, and the outer diameter of the convex portion is greater than the inner diameter of the first mounting tube.
[0014] In some embodiments, the first mounting tube and the second mounting tube are both made of stainless steel.
[0015] In some embodiments, the outer surface of the first mounting tube is provided with scales along the height direction.
[0016] In some embodiments, the nuclear power plant ventilation system heater flow detection device also includes an industrial computer connected to the pyroelectric flowmeter.
[0017] In some embodiments, the industrial computer is connected to the thermal flow meter via a four-core cable.
[0018] The implementation of the utility model has the following beneficial effects: the flow detection device of the heater of the ventilation system of a nuclear power plant includes a mounting seat and a pyroelectric flowmeter, the pyroelectric flowmeter is mounted on the air duct through the mounting seat, the pyroelectric flowmeter can judge the flow size in the air duct by the fluid temperature, and by measuring the flow size in the air duct, it can judge whether the heater has a dry burning risk according to the fluid temperature, and when the heater has a dry burning risk, the heater can be shut down to protect the heater. The flow detection device of the heater of the ventilation system of a nuclear power plant has high stability and high measurement accuracy, and can be calibrated and tested domestically, which is more convenient. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the technical solution of the utility model, the utility model will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show certain embodiments of the utility model, and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:
[0020] Figure 1 It is a structural schematic diagram of a flow detection device for a heater of a ventilation system of a nuclear power plant in some embodiments of the utility model;
[0021] Figure 2 It is a structural schematic diagram of a flow detection device for a heater of a ventilation system of a nuclear power plant in other embodiments of the utility model;
[0022] Figure 3 It is a partial detail diagram of a flow detection device for a heater in a ventilation system of a nuclear power plant in some embodiments of the utility model. DETAILED DESCRIPTION
[0023] 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.
[0024] 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.
[0025] 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.
[0026] See also Figures 1 to 3 The utility model shows a flow detection device for a heater of a ventilation system of a nuclear power plant, comprising a mounting base 10 mounted on an air duct 100 and communicating with the inner cavity of the air duct 100, and a pyroelectric flowmeter 20 detachably mounted on the mounting base 10; the pyroelectric flowmeter 20 comprises a body 21, a mounting portion 22 connected to the body 21, and a probe 23 connected to the body 21, the probe 23 extends into the inner cavity of the air duct 100, and the outer periphery of the mounting portion 22 is provided with an external thread.
[0027] like Figure 1 As shown, the mounting seat 10 includes at least one nut seat 11, and the inner cavity of the nut seat 11 is provided with an internal thread matching the external thread. Figure 2As shown, the mounting base 10 may include a first mounting tube 12 and a second mounting tube 13. The first mounting tube 12 is fixed on the air duct 100, and the inner cavity of the first mounting tube 12 is connected to the inner cavity of the air duct 100. The outer diameter of the second mounting tube 13 is smaller than the inner diameter of the first mounting tube 12. The inner wall surface of the second mounting tube 13 is provided with an inner thread matching the outer thread. The first mounting tube 12 is provided with a through hole 121 along the height direction for the fastener 30 to pass through to tighten the outer side surface of the second mounting tube 13, so that the relative height of the first mounting tube 12 and the second mounting tube 13 can be adjusted, thereby realizing the adjustment of the height position of the thermal flowmeter 20, thereby improving the applicability of the flow detection device of the heater of the ventilation system of the nuclear power plant.
[0028] The pyroelectric flowmeter 20 can determine the flow rate in the air duct 100 by the fluid temperature. By measuring the flow rate in the air duct 100, it can determine whether the heater has a risk of dry burning according to the fluid temperature. When the heater has a risk of dry burning, the heater can be shut down to protect the heater.
[0029] By using the pyroelectric flowmeter 20 in combination with the mounting base 10, the problems of high product failure rate, inaccurate measurement, and inability to calibrate existing in the original flap-type flow switch can be avoided.
[0030] Preferably, the pyroelectric flowmeter 20 can be selected as model SA4300. Of course, the pyroelectric flowmeter 20 can also select a suitable signal according to actual needs, which is not specifically limited here.
[0031] like Figure 1 As shown, the number of the nut seats 11 is two, the two nut seats 11 are axially stacked together, and the two nut seats 11 are coaxially arranged. The inner cavities of the two nut seats 11 are connected, and the inner cavities of the two nut seats 11 can be provided with internal threads, or one of the nut seats 11 is provided with internal threads, while the other nut seat 11 is not provided with internal threads. For example, the nut seat 11 close to the air duct 100 is not provided with internal threads, while the nut seat 11 away from the air duct 100 can be provided with internal threads. Preferably, the nut seat 11 can be made of stainless steel, for example, 316L stainless steel. In some embodiments, the number of the nut seats 11 can also be three, four or any other number, which is not specifically limited here.
[0032] In some embodiments, the two nut seats 11 are welded and fixed. The nut seats 11 can be welded and fixed to the outer periphery of the measuring port of the air duct 100 .
[0033] like Figure 2 and Figure 3As shown, in some embodiments, the through holes 121 may be arranged at intervals along the axial direction and the circumferential direction of the first mounting cylinder 12, so that the first mounting cylinder 12 and the second mounting cylinder 13 can have a larger adjustment range after being matched with each other. Preferably, the through holes 121 may be threaded holes.
[0034] The circumferential outer side surface of the second mounting tube 13 is provided with a plurality of limit grooves 131 along the height direction for the end of the fastener 30 to be inserted therein. The limit grooves 131 may be threaded grooves, and the plurality of limit grooves 131 may be arranged at intervals along the axial and circumferential directions of the second mounting tube 13, so that the second mounting tube 13 may have a larger adjustment range.
[0035] In some embodiments, the fastener 30 includes, but is not limited to, a bolt, a screw, or a latch.
[0036] In some embodiments, a convex portion 132 extends outwardly from the circumferential outer surface of the upper end of the second mounting tube 13, and the outer diameter of the convex portion 132 is larger than the inner diameter of the first mounting tube 12. This prevents the second mounting tube 13 from falling into the first mounting tube 12, making the second mounting tube 13 safe to use.
[0037] In some embodiments, the first installation tube 12 and the second installation tube 13 are both made of stainless steel, for example, they can be made of stainless steel material. The first installation tube 12 and the second installation tube 13 can both be cylindrical structures.
[0038] In some embodiments, the outer surface of the first mounting tube 12 is provided with a scale along the height direction. The zero point of the scale can be set at the top, and the values gradually increase from top to bottom, or the zero point of the scale can be set at the bottom, and the values gradually increase from bottom to top. The scale is set to understand the adjustment range of the first mounting tube 12.
[0039] Since the end of the probe 23 (or the probe rod) of the pyroelectric flowmeter 20 cannot contact the inner wall surface of the air duct 100, the use of a mounting base 10 with an adjustable overall height dimension can facilitate the adjustment of the installation position of the pyroelectric flowmeter 20, which has better applicability.
[0040] In some embodiments, the flow detection device for the heater of the ventilation system of a nuclear power plant further includes an industrial computer (not shown) connected to the pyroelectric flowmeter 20, and the industrial computer may include but is not limited to a PLC industrial computer. Furthermore, the industrial computer is connected to the pyroelectric flowmeter 20 via a four-core cable, and the length of the four-core cable may be extended by a connector. Preferably, the industrial computer can be connected to the heater, and the industrial computer can adjust the working state of the heater according to the pyroelectric flowmeter 20. For example, when the pyroelectric flowmeter 20 detects an abnormal fluid temperature, the industrial computer can control the heater to shut down. Of course, it can be manually shut down by staff, which is not specifically limited here.
[0041] It can be understood that the flow detection device of the heater of the ventilation system of the nuclear power plant includes a mounting base 10 and a pyroelectric flowmeter 20. The pyroelectric flowmeter 20 is installed on the air duct 100 through the mounting base 10. The pyroelectric flowmeter 20 can judge the flow rate in the air duct 100 by the fluid temperature. By measuring the flow rate in the air duct 100, it can judge whether the heater has a dry burning risk according to the fluid temperature. When the heater has a dry burning risk, the heater can be shut down to protect the heater. The flow detection device of the heater of the ventilation system of the nuclear power plant has high stability and high measurement accuracy, and can be calibrated and tested domestically, which is more convenient. Ultimately, the stability of the operation of the ventilation system of the nuclear power plant can be improved.
[0042] It can be understood that the above embodiments only express the preferred implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the utility model. It should be pointed out that, for ordinary technicians in this field, without departing from the concept of the utility model, the above-mentioned technical features can be freely combined, and several deformations and improvements can be made, which all belong to the protection scope of the utility model. Therefore, all equivalent changes and modifications made to the scope of the claims of the utility model should fall within the scope of the claims of the utility model.
Claims
1. A flow detection device for a heater in a ventilation system of a nuclear power plant, characterized in that: The invention comprises a mounting seat (10) mounted on an air duct (100) and connected to the inner cavity of the air duct (100), and a pyroelectric flowmeter (20) detachably mounted on the mounting seat (10); the pyroelectric flowmeter (20) comprises a body (21), a mounting portion (22) connected to the body (21), and a probe (23) connected to the body (21); the outer periphery of the mounting portion (22) is provided with an external thread; The mounting seat (10) includes at least one nut seat (11), the inner cavity of the nut seat (11) is provided with an internal thread matching the external thread; or, the mounting seat (10) includes a first mounting tube (12) and a second mounting tube (13), the first mounting tube (12) is fixed on the air duct (100), and the inner cavity of the first mounting tube (12) is connected to the inner cavity of the air duct (100), the outer diameter of the second mounting tube (13) is smaller than the inner diameter of the first mounting tube (12), the inner wall surface of the second mounting tube (13) is provided with an internal thread matching the external thread, and the first mounting tube (12) is provided with a through hole (121) along the height direction for a fastener (30) to pass through so as to press against the outer side surface of the second mounting tube (13).
2. The flow detection device for heater of ventilation system of nuclear power plant according to claim 1, characterized in that: The number of the nut seats (11) is two, the two nut seats (11) are axially stacked together, and the two nut seats (11) are coaxially arranged.
3. The flow detection device for the heater of the ventilation system of a nuclear power plant according to claim 2, characterized in that: The two nut seats (11) are fixed by welding.
4. The flow detection device for heater of ventilation system of nuclear power plant according to claim 1, characterized in that: The circumferential outer side surface of the second mounting tube (13) is provided with a plurality of limiting grooves (131) along the height direction for the end of the fastener (30) to be inserted therein.
5. The flow detection device for heater of ventilation system of nuclear power plant according to claim 1, characterized in that: The fastener (30) comprises a bolt, a screw or a latch.
6. The flow detection device for heater of ventilation system of nuclear power plant according to claim 1, characterized in that: A convex portion (132) extends outwardly from the circumferential outer surface of the upper end of the second mounting tube (13), and the outer diameter of the convex portion (132) is greater than the inner diameter of the first mounting tube (12).
7. The flow detection device for heater of ventilation system of nuclear power plant according to claim 1, characterized in that: The first installation tube (12) and the second installation tube (13) are both made of stainless steel.
8. The flow detection device for heater of ventilation system of nuclear power plant according to claim 1, characterized in that: The outer surface of the first mounting tube (12) is provided with scales along the height direction.
9. The device for detecting flow rate of a heater in a ventilation system of a nuclear power plant according to any one of claims 1 to 8, characterized in that: The nuclear power plant ventilation system heater flow detection device also includes an industrial computer connected to the pyroelectric flowmeter (20).
10. The flow detection device for heater of ventilation system of nuclear power plant according to claim 9, characterized in that: The industrial computer is connected to the thermal flowmeter (20) via a four-core cable.