Nuclear power plant primary loop pressure boundary leakage detection device

Abstract

The utility model is suitable for the technical field of instrument detection, and provides a nuclear power plant primary loop pressure boundary leakage detection device which comprises a base, a probe type steel cylinder fixedly installed on one side of the base, a temperature and humidity probe arranged inside the probe type steel cylinder, a through hole formed in the probe type steel cylinder, and spring pieces symmetrically installed at the two ends of the base. The spring piece is arranged on one side of the base, the magnet is arranged on the same side of the spring piece, the boss is arranged on the other side of the base, the thermoelectric conversion unit is arranged on the side face of the boss, the cold end of the thermoelectric conversion unit makes close contact with the radiator, and the electrical box is anchored to the radiator and connected with the temperature and humidity probe through a cable. The pressure boundary leakage monitoring device is high in reliability, wiring is avoided, convenient installation is achieved, maintenance convenience of the device is greatly improved, real-time monitoring of pressure boundary leakage can be achieved, possible tiny leakage can be detected in time, nucleation accidents are avoided, operation safety of a nuclear power plant is ensured, and economic benefits of the nuclear power plant are improved.

Description

Technical Field

[0001] This utility model belongs to the field of instrument detection technology, and in particular relates to a leakage detection device for the pressure boundary of the primary loop in a nuclear power plant. Background Technology

[0002] The pressure boundary of a nuclear power plant's reactor coolant system serves as the plant's second fission product barrier. During normal reactor operation, radioactive, high-temperature, high-pressure reactor coolant circulates within the system, carrying heat from the reactor core to the steam generator. Nuclear power plants are typically designed for a 60-year lifespan. During this lifespan, as equipment and components within the reactor coolant system age, small leaks may occur at the pressure boundary, leading to the release of radioactive materials. If not addressed promptly, these leaks could develop into large breaches, causing a serious Loss of Flow Accident (LOCA) in the primary coolant circuit. In fact, nuclear power plant technical specifications classify pressure boundary leaks as a type of operational leak and establish corresponding Operating Limits of Conditions (LOCs) and monitoring requirements, necessitating daily monitoring of pressure boundary leaks. Therefore, it is essential to install appropriate leak detection devices to detect pressure boundary leaks, promptly identify potential leak points, and prevent nuclear accidents.

[0003] Existing technologies primarily monitor the temperature and humidity of the surrounding environment for pressure boundary leaks. This involves monitoring the temperature and humidity of the air near the pipeline to determine if a leak has occurred. However, considering that nuclear power plants have thick insulation layers on pipelines and equipment at the pressure boundary to avoid unnecessary heat loss and thus reduce power generation efficiency during operation, the accuracy and stability of detecting pressure boundary leaks through ambient temperature and humidity are not ideal. Furthermore, there are also problems such as difficulty in arranging measuring points, inconvenient installation and wiring, and high equipment maintenance costs. Utility Model Content

[0004] The purpose of this utility model embodiment is to provide a pressure boundary leakage detection device for the primary loop of a nuclear power plant, so as to realize real-time monitoring of pressure boundary leakage, timely detection of possible leakage risks, and avoid the occurrence of nuclear accidents, aiming to solve the problems existing in the above-mentioned background art.

[0005] This utility model embodiment is implemented as follows: a nuclear power plant primary loop pressure boundary leakage detection device includes a base, and further includes:

[0006] A probe-type steel cylinder is fixedly installed on one side of the base. The probe-type steel cylinder has a hollow structure and a temperature and humidity probe is installed inside the probe-type steel cylinder. Multiple through holes are opened on the side of the temperature and humidity probe on the probe-type steel cylinder so that the temperature and humidity probe can effectively detect the environmental conditions outside the probe-type steel cylinder.

[0007] Spring plates are symmetrically installed at both ends of the base, and magnets are installed on the same side of both spring plates. The deformation characteristics of the spring plates are used to magnetically attach the device to the arc-shaped steel wrapping on the outside of the circular pipe insulation layer.

[0008] A boss is arranged on the other side of the base. A thermoelectric conversion unit is installed on the side of the boss. The outside of the boss and the thermoelectric conversion unit is covered with a heat insulation layer. The boss and the base are manufactured as a single unit. The boss provides a fixing function for the thermoelectric conversion unit and also has a heat conduction function to conduct heat to the hot end of the thermoelectric conversion unit.

[0009] A radiator is installed on the side of the thermoelectric conversion unit. The cold end of the thermoelectric conversion unit is in close contact with the radiator. The heat is converted into electrical energy by utilizing the temperature difference between the hot end and the cold end, so as to realize the self-powered power supply of the device.

[0010] An electrical box, which is anchored to a radiator, is connected to a temperature and humidity probe via a cable.

[0011] Preferably, the electrical box has a built-in power collection and management unit, a signal acquisition and processing unit, a microprocessor unit, and a communication unit;

[0012] The power collection and management unit is used to collect, manage and distribute the electrical energy generated by the thermoelectric conversion unit.

[0013] The signal acquisition and processing unit is used to acquire and process temperature and humidity signals;

[0014] The microprocessor unit is used to record temperature and humidity signals, identify abnormal trends, and generate alarm logic.

[0015] The communication unit is used to realize wireless communication of signals.

[0016] Preferably, an antenna is also installed on the electrical box, and the antenna is electrically connected to the communication unit.

[0017] Preferably, the temperature and humidity probe covers a temperature range of 0-500℃ and a humidity range of 0-100%.

[0018] Preferably, the probe-type steel cylinder is made of iron material that is resistant to high temperature and radiation, and the probe-type steel cylinder is coated with a heat-insulating coating to avoid its circumferential heat conduction from introducing interference and errors into the temperature measurement process.

[0019] The boss is preferably made of a metal material with good thermal conductivity.

[0020] The thermoelectric conversion unit is designed based on static thermoelectric conversion materials, with bismuth telluride material being the preferred material.

[0021] The nuclear power plant primary loop pressure boundary leakage detection device provided in this embodiment of the utility model has the following technical effects:

[0022] 1. Based on a specially packaged temperature and humidity sensor, it adopts a self-powered technology based on thermoelectric conversion, which enables the device to be self-powered, thus achieving high reliability.

[0023] 2. The entire monitoring device eliminates the need for power supply cables and measurement cables, enabling convenient installation and significantly improving the ease of maintenance of the device itself;

[0024] 3. It can realize real-time monitoring of pressure boundary leakage, and timely detect possible minute leaks to prevent them from developing into nuclear accidents, ensuring the safe operation of nuclear power plants and improving the economic benefits of nuclear power plants. Attached Figure Description

[0025] Figure 1 A schematic diagram of the structure of the nuclear power plant primary loop pressure boundary leakage detection device provided in this embodiment of the utility model;

[0026] In the attached diagram: 1-Probe-type steel cylinder; 2-Temperature and humidity probe; 3-Through hole; 4-Base; 5-Spring sheet; 6-Magnet; 7-Boss; 8-Thermoelectric conversion unit; 9-Insulation layer; 10-Radiator; 11-Cable; 12-Electrical box; 13-Power collection and management unit; 14-Signal acquisition and processing unit; 15-Microprocessor unit; 16-Communication unit; 17-Antenna. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0028] The specific implementation of this utility model will be described in detail below with reference to specific embodiments.

[0029] like Figure 1The diagram shows the structure of a nuclear power plant primary loop pressure boundary leakage detection device according to an embodiment of this utility model. It includes a base 4, a probe-type steel cylinder 1, spring plates 5, a boss 7, a radiator 10, and an electrical box 12. The probe-type steel cylinder 1 is fixedly installed on one side of the base 4. The probe-type steel cylinder 1 has a hollow structure, and a temperature and humidity probe 2 is installed inside. Multiple through holes 3 are opened on the side of the temperature and humidity probe 2 on the probe-type steel cylinder 1 to allow the temperature and humidity probe 2 to effectively detect the external environment of the probe-type steel cylinder 1. The spring plates 5 are symmetrically installed at both ends of the base 4, and magnets 6 are installed on the same side of both ends of the spring plates 5. The deformation characteristics of the spring plates 5 are used to magnetically attach the device tightly to the circular pipe. The outer side of the insulation layer is wrapped with an arc-shaped steel structure; the boss 7 is arranged on the other side of the base 4, and the thermoelectric conversion unit 8 is installed on the side of the boss 7. The outside of the boss 7 and the thermoelectric conversion unit 8 is covered with a heat insulation layer 9 to prevent heat from dissipating into the environment; the boss 7 and the base 4 are integrally manufactured. The boss 7 provides a fixing function for the thermoelectric conversion unit 8 and also has a heat conduction function to conduct heat to the hot end of the thermoelectric conversion unit; the radiator 10 is installed on the side of the thermoelectric conversion unit 8. The cold end of the thermoelectric conversion unit 8 is in close contact with the radiator. The heat is converted into electrical energy by utilizing the temperature difference between the hot end and the cold end to realize the self-powered power supply of the device; the electrical box 12 is anchored on the radiator 10 and is connected to the temperature and humidity probe 2 through the cable 11.

[0030] In one embodiment of this utility model, in order to improve the reliability of the device itself, the temperature and humidity probe 2 is redundantly arranged. The measurement range of the temperature and humidity probe 2 meets the requirements for pressure boundary leakage detection. The temperature range of the temperature and humidity probe 2 covers 0-500℃ and the humidity range covers 0-100%. In addition, the installation is more flexible. Compared with bolts, anchors and other fixing methods, the magnetic fixing method can avoid damage to the integrity of the insulation layer.

[0031] like Figure 1 As shown, in a preferred embodiment of the present invention, the electrical box 12 has a built-in power collection and management unit 13, a signal acquisition and processing unit 14, a microprocessor unit 15 and a communication unit 16.

[0032] The power collection and management unit 13 is used to collect, manage and distribute the electrical energy generated by the thermoelectric conversion unit 8;

[0033] The signal acquisition and processing unit 14 is used to acquire and process temperature and humidity signals;

[0034] The microprocessor unit 15 is used to implement temperature and humidity signal recording, trend anomaly detection, and alarm logic;

[0035] The communication unit 16 is used to realize wireless communication of signals;

[0036] An antenna 17 is also installed on the electrical box 12, and the antenna 17 is electrically connected to the communication unit 16.

[0037] In one embodiment of this utility model, the signal acquisition and processing unit 14, the microprocessor unit 15 and the temperature and humidity probe 2 are all powered by the thermoelectric conversion unit 8. The thermoelectric conversion unit 8 realizes power acquisition based on the temperature difference between the outer side of the insulation layer and the environment. The thermoelectric conversion unit 8 is designed based on static thermoelectric conversion materials, preferably bismuth telluride material, but other static thermoelectric conversion materials can also be used.

[0038] like Figure 1 As shown, in another preferred embodiment of this utility model, the probe-type steel cylinder 1 is made of iron material that is resistant to high temperature and radiation. The probe-type steel cylinder 1 is coated with a heat-insulating coating on the outside to avoid its circumferential heat conduction from introducing interference and errors into the temperature measurement process.

[0039] In one embodiment of this utility model, the boss 7 is preferably made of a metal material with good thermal conductivity.

[0040] In summary, during use, the device is fixed to the outer steel casing of the insulation layer. The probe-type steel cylinder 1 is inserted deep into the insulation layer, with the embedment depth matching the length of the probe-type steel cylinder 1. The size of the probe-type steel cylinder 1 should be selected to match the thickness of the insulation layer. On the one hand, the probe-type steel cylinder 1 should not be too short and too close to the outer side of the insulation layer, otherwise it will lead to a serious lag in response and a decrease in sensitivity. On the other hand, it should not be too deep and contact the pipes or equipment on the pressure boundary, otherwise it will lead to a reduction in the detection coverage area for leak detection and a decrease in reliability. Generally, the embedment depth can be selected as 2 / 3 of the insulation layer thickness.

[0041] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.

[0042] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. Leak detection device for a primary circuit pressure boundary of a nuclear power plant, comprising a base, characterized in that, Also include: The probe type steel cylinder is fixedly installed on one side of the base, the probe type steel cylinder is a hollow structure, the probe type steel cylinder is provided with a temperature and humidity probe inside, a plurality of through holes are formed on the side of the probe type steel cylinder to enable the temperature and humidity probe to effectively detect the environmental conditions outside the probe type steel cylinder; The spring sheet is symmetrically installed at both ends of the base, and the same side of the two end spring sheets is provided with a magnet, and the deformation characteristics of the spring sheet are utilized to magnetically attract the device to the arc-shaped steel wrapping outside the circular pipeline heat preservation layer; The boss is arranged on the other side of the base, the side of the boss is provided with a thermoelectric conversion unit, the outer side of the boss and the thermoelectric conversion unit is covered with a thermal insulation layer, the boss is integrally processed and manufactured with the base, the boss provides a fixing function for the thermoelectric conversion unit while having a heat conducting function, so as to conduct heat to the hot end of the thermoelectric conversion unit; The radiator is installed on the side of the thermoelectric conversion unit, the cold end of the thermoelectric conversion unit is in close contact with the radiator, the temperature difference between the hot end and the cold end is utilized to convert heat into electric energy, so as to realize self-power supply of the device; The electrical box is anchored on the radiator, and the electrical box is connected with the temperature and humidity probe through the cable.

2. The nuclear power plant primary circuit pressure boundary leak detection apparatus according to claim 1, characterized by, The electrical box is provided with an electric quantity collection and management unit, a signal acquisition and processing unit, a micro processing unit and a communication unit; The electric quantity collection and management unit is used to realize the collection, management and distribution of the electric energy generated by the thermoelectric conversion unit; The signal acquisition and processing unit is used to acquire and process temperature and humidity signals; The micro processing unit is used to realize temperature and humidity signal recording, trend abnormality discrimination and alarm logic; The communication unit is used to realize wireless communication of signals.

3. The nuclear power plant primary circuit pressure boundary leak detection apparatus according to claim 2, characterized by, The antenna is also installed on the electrical box and is electrically connected with the communication unit.

4. The nuclear power plant primary circuit pressure boundary leak detection apparatus according to claim 1, characterized by, The temperature range of the temperature and humidity probe covers 0-500℃, and the humidity range covers 0-100%.

5. The nuclear power plant primary circuit pressure boundary leak detection apparatus according to claim 1, characterized by, The probe type steel cylinder is made of high-temperature and radiation-resistant iron material, and the outer surface of the probe type steel cylinder is sprayed with a thermal insulation coating to avoid the introduction of interference and error by circumferential heat conduction during temperature measurement; The boss is made of metal material; The thermoelectric conversion unit is designed based on static thermoelectric conversion material and is made of bismuth telluride material.

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