A reactor coolant temperature monitoring method and system thereof

Abstract

The application discloses a reactor coolant temperature monitoring method and system, and the reactor comprises a reactor core, a primary loop connected with the reactor core, and a bypass pipeline arranged on the primary loop; an upper chamber is arranged on the reactor core; the reactor coolant temperature monitoring method comprises the following steps: acquiring the bypass pipeline coolant temperature, the upper chamber coolant temperature and all the main pump operating conditions of the primary loop; and selecting the bypass pipeline coolant temperature or the upper chamber coolant temperature as the reactor coolant temperature according to all the main pump operating conditions. Through the above arrangement, the application can select the monitoring method of the reactor coolant temperature according to all the main pump operating conditions, and can realize the normal monitoring of the coolant temperature when all the main pump operating conditions are abnormal.

Description

Technical Field

[0001] This invention relates to the field of nuclear power technology, and in particular to a method and system for monitoring reactor coolant temperature. Background Technology

[0002] Reactor coolant temperature, a crucial thermal parameter in nuclear power plants, must be input into the reactor control and protection systems. Therefore, monitoring reactor coolant temperature requires extremely high accuracy and real-time performance. However, in practice, the fuel assemblies in the reactor core are composed of different rod bundles. Due to the uneven heat generation of these bundles, the coolant temperature varies across different channels. Although there is some mixing as the coolant flows from the core through the upper chamber into the main duct, this mixing effect is limited, and thermal stratification still exists in the main duct. Because of this thermal stratification, accurate measurement of the coolant temperature in a specific hot loop section of the reactor system is typically achieved by measuring the temperature of the bypass circuit within the loop.

[0003] However, there are situations where the main pump in the circuit may malfunction due to certain accident conditions. In such cases, the temperature results monitored in the bypass will lose their accuracy and validity. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method and system for monitoring reactor coolant temperature.

[0005] The technical solution adopted by this invention to solve its technical problem is: constructing a reactor coolant temperature monitoring method, wherein the reactor includes a reactor core, a primary loop connected to the reactor core, the primary loop is provided with a bypass pipe, and an upper chamber is provided on the reactor core, and the reactor coolant temperature monitoring method includes:

[0006] S1: Obtain the bypass pipe coolant temperature, upper chamber coolant temperature, and operating conditions of all main pumps in the primary circuit;

[0007] S2: Select the bypass pipeline coolant temperature or the upper chamber coolant temperature as the reactor coolant temperature based on the operating conditions of all main pumps.

[0008] Preferably, step S2 includes:

[0009] When all the main pumps are operating normally, the bypass pipeline coolant temperature is selected as the reactor coolant temperature.

[0010] When all the main pumps are in a stopped operating condition, the upper chamber coolant temperature is selected as the reactor coolant temperature.

[0011] Preferably, in step S1, the step of obtaining the upper chamber coolant temperature includes: installing a monitoring device in the upper chamber and obtaining the upper chamber coolant temperature through the monitoring device.

[0012] Preferably, in step S1, obtaining the bypass pipe coolant temperature, the upper chamber coolant temperature, and the operating conditions of all main pumps involves: obtaining bypass pipe coolant temperature signals, upper chamber coolant temperature signals, and main pump operating condition signals.

[0013] The main pump operating condition is obtained based on the main pump operating signal, and the main pump operating condition includes a normal operating signal and a pump stop signal.

[0014] The bypass pipe coolant temperature is obtained based on the bypass pipe coolant temperature signal;

[0015] The upper chamber coolant temperature is obtained based on the upper chamber coolant temperature signal;

[0016] Step S2 is replaced by: when the main pump switches from the normal operation signal to the pump stop signal, the bypass pipeline coolant temperature signal is triggered to switch to the upper chamber coolant temperature signal, and the upper chamber coolant temperature is used as the reactor coolant temperature.

[0017] Preferably, the bypass pipe coolant temperature is the coolant temperature of a certain hot section in the bypass pipe or the average of the coolant temperatures of multiple hot sections in the bypass pipe; the upper chamber coolant temperature is the coolant temperature at the center of the upper chamber or the average of the coolant temperatures at multiple locations in the upper chamber.

[0018] A reactor coolant temperature monitoring system, employing any one of the reactor coolant temperature monitoring methods described above, the monitoring system comprising a monitoring device and a processing device, the monitoring device being connected to the processing device, the monitoring device comprising:

[0019] At least one first temperature monitoring device: for acquiring the temperature of the hot section coolant in the bypass pipeline;

[0020] At least one second temperature monitoring device for acquiring the coolant temperature in the upper chamber;

[0021] Main pump monitoring device: used to obtain the operating conditions of the main pump;

[0022] The processing device is used to receive data from the first temperature monitoring device, the second temperature monitoring device, and the main pump monitoring device, process the data, and output the data.

[0023] Preferably, the second temperature monitoring device is located above the centerline of the pressure vessel inlet and outlet nozzles, and is located directly above the fuel assembly in the middle of the reactor core.

[0024] Preferably, when multiple second temperature monitoring devices are provided, the multiple second temperature monitoring devices are arranged around the center of the reactor core, and each second temperature monitoring device is located directly above its corresponding fuel assembly.

[0025] Preferably, the second temperature monitoring device is connected to the integrated measurement component of the core measurement system.

[0026] Preferably, the first temperature monitoring device is a temperature monitoring thermocouple and / or the second temperature monitoring device is a temperature monitoring thermocouple.

[0027] Implementing this invention has the following beneficial effects: This invention can select the reactor coolant temperature monitoring method according to the operating conditions of all main pumps, and can realize normal monitoring of coolant temperature when the operating conditions of all main pumps are abnormal; ensuring the accuracy and effectiveness of the monitored reactor coolant temperature results.

[0028] This invention also ensures normal monitoring of coolant temperature under normal operating conditions and under all main pump shutdown conditions. Attached Figure Description

[0029] To more clearly illustrate the technical solution of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort. In the drawings:

[0030] Figure 1 This is a schematic diagram of the temperature monitoring method of the present invention;

[0031] Figure 2 This is a front view of the upper chamber coolant temperature monitoring scheme of the present invention;

[0032] Figure 3 This is a top view of the arrangement scheme of the upper chamber coolant temperature monitoring device of the present invention;

[0033] Figure 4 This is a schematic diagram of the upper chamber coolant temperature signal switching method of the present invention;

[0034] Figure 5 This is a schematic diagram of the bypass temperature measurement scheme of the present invention;

[0035] Figure 6 This is a schematic diagram of the coolant flow direction after the main pump of the present invention is stopped.

[0036] Explanation of reference numerals in the attached figures:

[0037] 11-First temperature monitoring device; 21-Second temperature monitoring device; 2-Upper chamber; 3-Integrated measurement assembly; 4-Pressure vessel; 5-Fuel assembly; 6-Core; 7-Main pipeline; 8-Bypass pipeline; 9-Main pump; 10-Steam generator; 12-Reactor pressure vessel. Detailed Implementation

[0038] To provide a clearer understanding of the technical features, objectives, and effects of this invention, specific embodiments are now described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," and "outer" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing the technical solution and do not indicate that the device or element referred to must have a specific orientation; therefore, they should not be construed as limitations on this invention.

[0039] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "connected," "linked," and "set up" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. When an element is referred to as being "on" or "below" another element, the element can be located "directly" or "indirectly" on the other element, or there may be one or more intermediary elements. The terms "first," "second," etc., are only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0040] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0041] As described in the background section, due to the existence of thermal stratification, a bypass temperature measurement scheme is typically used to accurately measure the temperature of the primary loop hot section coolant in a reactor system. For example, the present invention provides a loop structure as follows: Figure 5-6 As shown, the reactor pressure vessel 12 is connected to the steam generator 10, which is connected to the reactor pressure vessel through the main pipeline 7. A main pump 9 is installed on the main pipeline 7 to form a loop for circulating coolant. A bypass pipeline 8 is installed on the main pipeline 7 to monitor the coolant temperature in the bypass pipeline 8.

[0042] Coolant from different locations in the main pipe 7 is introduced into the bypass pipe 8 at the same cross-section for uniform mixing. The temperature of the coolant in the bypass pipe 8 represents the temperature of the coolant in the main pipe 7. The flow of coolant in the bypass pipe 8 is driven by the main pump 9. Since the pressure at point A is higher than the pressure at point B, the coolant at point A can flow to point B, thus allowing the coolant in the bypass pipe to flow normally.

[0043] However, when the main pump stops operating under certain accident conditions, this circuit will enter a natural circulation state, such as... Figure 5-6 As shown, the cold source is the steam generator 10, and the heat source is the reactor core within the reactor pressure vessel 12. In this case, the steam generator 10 functions similarly to the main pump 9, providing the driving force for the coolant flow. Therefore, the pressure at point B will be higher than the pressure at point A, and the coolant at point B will flow towards point A. Consequently, under this operating condition, the coolant temperature in the bypass pipe 8 cannot represent the hot section coolant temperature at the core outlet, and the bypass pipe coolant temperature monitoring fails. Therefore, under the above circumstances, the method for monitoring and acquiring the coolant temperature needs to be improved to ensure accurate acquisition of the reactor coolant temperature even when the main pump 9 experiences abnormal operating conditions or even shuts down.

[0044] Example 1:

[0045] Please see Figure 1 This embodiment illustrates a method for monitoring reactor coolant temperature. The reactor includes a core, a primary loop connected to the core, a bypass pipe in the primary loop, and an upper chamber on the core. The reactor coolant temperature monitoring method includes:

[0046] S1: Obtain the bypass pipe coolant temperature, upper chamber coolant temperature, and operating conditions of all main pumps in the primary circuit;

[0047] S2: Select either the bypass pipeline coolant temperature or the upper chamber coolant temperature as the reactor coolant temperature based on the operating conditions of all main pumps.

[0048] The circuit is a loop of the reactor coolant in the reactor system; the bypass pipe is a hot section of a bypass in the circuit; the bypass pipe coolant temperature is the temperature of the coolant measured in the hot section of the bypass; the upper chamber is a chamber located above the reactor core in the reactor pressure vessel of the reactor; the upper chamber coolant temperature is the temperature of the coolant measured in the upper chamber; the main pump is located in the circuit.

[0049] In this embodiment, the method for determining coolant temperature can be quickly switched based on the operating conditions of all main pumps, thereby rapidly and effectively solving the problem of coolant temperature monitoring failure under special circumstances. In this embodiment, the bypass pipe coolant temperature and the upper chamber coolant temperature in a certain loop are simultaneously acquired, and both temperature data are recorded and stored simultaneously to address different methods of determining reactor coolant temperature under different operating conditions of all main pumps. When determining the operating conditions of all main pumps, if all main pumps are operating normally, the loop is functioning normally, and the bypass pipe temperature monitoring is normal; in this case, the initial coolant temperature determination method is maintained, and the bypass pipe coolant temperature is selected as the reactor coolant temperature. However, if all main pumps are found to be malfunctioning, the bypass pipe coolant temperature can no longer represent the hot section coolant temperature at the core outlet, indicating bypass pipe coolant temperature monitoring failure. Therefore, the upper chamber coolant temperature is selected as the reactor coolant temperature. The above methods can effectively and quickly respond to the operating conditions of the main pump, rapidly and accurately select and determine the temperature of the coolant, and ensure the normal operation of the entire nuclear power plant system.

[0050] Furthermore, in step S2, the abnormality includes the situation where all main pumps stop operating. That is, when all main pumps are operating normally, the bypass pipeline coolant temperature is selected as the reactor coolant temperature; when all main pumps are stopped, the upper chamber coolant temperature is selected as the reactor coolant temperature.

[0051] Further details are attached. Figure 2 As shown, in step S1, the step of obtaining the coolant temperature in the upper chamber includes: installing a monitoring device in the upper chamber and obtaining the coolant temperature in the upper chamber through the monitoring device. Since reactors are generally equipped with a core monitoring system, and the measuring components in the core monitoring system are generally integrated, the method for obtaining the coolant temperature in this embodiment can be as shown in the attached figure. Figure 2As shown, the coolant temperature of the upper chamber 2 is obtained by adding a monitoring device located in the upper chamber 2 to the integrated measurement assembly 3 of the core monitoring system. In core monitoring systems, to simultaneously monitor core neutron flux and core outlet temperature, an integrated measurement assembly 3 is often used. This means the electrical wiring connecting the measurement device typically runs from the top of the reactor core to the bottom of the core 6. In this case, only the monitoring device in the upper chamber 2 needs to be added to the integrated measurement assembly 3; its wiring can be directly connected to the integrated measurement assembly 3 to achieve coolant temperature monitoring in the upper chamber 2. Therefore, this method is based on the existing integrated measurement assembly 3 in the core measurement system, requiring no additional wiring. It can be directly used on the existing wiring layout, providing a reasonable and feasible way to monitor the coolant temperature of the upper chamber 2 and improving the ease of implementation.

[0052] In some specific implementations of this embodiment, in step S1, obtaining the bypass pipe coolant temperature, the upper chamber coolant temperature, and the operating conditions of all main pumps is as follows: obtaining the bypass pipe coolant temperature signal, the upper chamber coolant temperature signal, and the main pump operating condition signal;

[0053] That is, the operating status of the main pump is obtained based on the main pump operating signal, including normal operation signal and pump stop signal;

[0054] The bypass pipe coolant temperature is obtained from the bypass pipe coolant temperature signal;

[0055] The upper chamber coolant temperature is obtained from the upper chamber coolant temperature signal;

[0056] Step S2 can be specifically replaced by: when the main pump switches from the normal operation signal to the pump stop signal, the bypass pipeline coolant temperature signal is triggered to switch to the upper chamber coolant temperature signal, and the upper chamber coolant temperature is used as the reactor coolant temperature.

[0057] In the above-described manner, when the main pump is shut down, the upper chamber coolant temperature signal can be directly used to replace the bypass pipe coolant temperature signal. This can be directly applied to nuclear power plant systems. For example, it can be directly used as input for reactor protection systems, and also as input for reactor control systems such as core coolant average temperature control and over-temperature and over-power ΔT protection.

[0058] In the application of the above method, the acquisition of the coolant temperature of the bypass pipeline can be achieved by acquiring the coolant temperature of a certain hot section in the bypass, or even by acquiring the coolant temperature of multiple hot sections in the bypass and taking the average value of the coolant temperatures of the multiple hot sections.

[0059] In the application of the above method, the temperature of the coolant in the upper chamber can be obtained by taking the temperature value measured at the center of the upper chamber 2. Alternatively, the coolant temperature can be obtained at multiple locations within the upper chamber 2, and the average of the measured temperatures at these multiple locations can be taken. Preferably, these multiple locations are concentrated in the center of the upper chamber 2.

[0060] In this embodiment, it should be noted that due to the thermal stratification of the coolant in the upper chamber 2, the overall coolant temperature in the middle of the core 6 is higher than that in the outer periphery. Therefore, the coolant temperature in the upper chamber 2 obtained by the above method, when used as the final coolant temperature, is actually slightly higher than the average temperature of the hot section coolant. Thus, when the result obtained in this way is used as input to the reactor protection system, it can trigger the reactor protection system earlier, thereby increasing the protection speed for the core 6 and further ensuring the operational safety of the core 6. When using signal input, under the condition that all main pumps are shut down, the coolant temperature signal in the upper chamber 2 will be larger than the average temperature signal of the hot section coolant, which also means that the reactor protection system will be triggered earlier. From the perspective of core 6 safety, earlier activation of the reactor protection system is more beneficial to the safety of the core 6. Therefore, this embodiment can not only quickly and accurately reflect and obtain the average temperature of the reactor coolant, but also trigger the protection operation of the reactor protection system earlier, improving safety.

[0061] Example 2:

[0062] Please see Figure 2-4 This embodiment provides a reactor coolant temperature monitoring system. The system applies the reactor coolant temperature monitoring method described in Embodiment 1 above. The monitoring system includes a monitoring device and a processing device, and the monitoring device is connected to the processing device.

[0063] Its processing unit is used to receive data from the first temperature monitoring device, the second temperature monitoring device and the main pump monitoring device, process the data and output it;

[0064] Its monitoring devices include:

[0065] At least one first temperature monitoring device 11: for acquiring the temperature of the hot section coolant in the bypass pipe 8;

[0066] At least one second temperature monitoring device 21: for acquiring the coolant temperature in the upper chamber 2;

[0067] Main pump monitoring device: used to obtain the operating conditions of the main pump.

[0068] In the monitoring system of this embodiment, the processing device is equipped with a processor that can receive, parse, and execute corresponding commands to control the control flow of the detection system. The first temperature monitoring device 11 is in contact with the bypass pipe 8 to obtain the temperature of the hot section coolant in the bypass pipe 8. The second temperature monitoring device 21 is located inside the upper chamber 2, concentrated in the middle of the upper chamber 2, to obtain the temperature of the coolant in the upper chamber 2. The main pump monitoring device is connected to the main pump to monitor and obtain the operating condition of the main pump. During initial normal operation, the system receives and inputs the data or signals from the first temperature monitoring device 11. When the main pump monitoring device detects that all main pumps have stopped running, it immediately sends a feedback signal to the system. At this time, the system switches to receiving and inputting the data or signals from the second temperature monitoring device 21. The entire process realizes closed-loop system processing, effectively solving the problem of bypass temperature data failure caused by the main pump operating condition.

[0069] In this embodiment, the reactor is also equipped with a core monitoring system. This core monitoring system can be set up independently of the temperature monitoring system in this embodiment or Embodiment 1, and connected to the processing device of the temperature monitoring system. Alternatively, the core monitoring system can be a subsystem of the temperature monitoring system in this embodiment and connected to its processing device. In the core monitoring system, due to the integrated measurement component 3 design, inserted from the top of the reactor core to the bottom of the core 6, a self-powered neutron detector and a core 6 outlet temperature monitor are simultaneously arranged to monitor the core neutron flux and core outlet temperature. Therefore, the first temperature monitoring device 11 installed in the bypass pipe 8 can be an integrated temperature monitoring device already installed in the bypass pipe 8. Since it is necessary to add monitoring of the coolant temperature in the upper chamber 2, a second temperature monitoring device 21 needs to be added to the upper chamber 2. During arrangement, it is only necessary to add a corresponding temperature monitoring device to the integrated measurement component 3 to achieve upper chamber 2 coolant temperature monitoring. That is, the second temperature monitoring device 21 is connected to the integrated measurement component 3 of the core 6 measurement system, thus simplifying the addition and arrangement process.

[0070] Furthermore, based on the above, the arrangement of the second temperature monitoring device 21 is improved, as shown in the attached figure. Figure 2-3 As shown, the second temperature monitoring device 21 is located above the centerline C of the inlet and outlet nozzles of the pressure vessel 4, and is positioned directly above the fuel assembly 5 in the middle of the reactor core 6. This arrangement improves the accuracy of temperature monitoring and enhances the precision of the monitoring results.

[0071] Furthermore, when a single second temperature monitoring device 21 is provided, it is positioned directly above the fuel assembly 5 at the center of the core 6; while when multiple second temperature monitoring devices 21 are provided, they are arranged around the center of the core 6, with each second temperature monitoring device 21 positioned directly above its corresponding fuel assembly 5. In one example of this embodiment, as shown in the attached... Figure 3 As shown, the reactor core 6 fuel assembly 5 is typically arranged with 37 fuel assemblies 5. In this example, four second temperature monitoring devices 21 are used. These four devices are positioned above the centerline C of the inlet / outlet nozzles of the pressure vessel 4, and are arranged around the center of the reactor core 6. Each second temperature monitoring device 21 is positioned directly below a fuel assembly 5. It should be noted that the arrangement of the second temperature monitoring devices 21 in this embodiment is not only applicable to the aforementioned number of reactor core 6 fuel assemblies, but also to other numbers of reactor core 6 fuel assemblies 5.

[0072] In the above-described Embodiment 1 or Embodiment 2, the temperature monitoring device mentioned includes a first temperature monitoring device 11 and a second temperature monitoring device 21, preferably a temperature monitoring thermocouple. Thermocouples are commonly used components in temperature measurement, and their principle is based on the thermoelectric effect. When there is a temperature difference between the two thermoelectrodes of a thermocouple, an electromotive force (EMF) is generated, which is proportional to the temperature difference. The temperature of the measured medium can be calculated by measuring the EMF. Optionally, the temperature monitoring device can also use a thermometer for measurement, such as a wide-range thermometer or a narrow-range thermometer. The thermometer can be inserted into the pipe through a sampling interface installed on the main pipe wall, directly contacting the coolant for temperature measurement. This method has high measurement accuracy and can monitor the temperature changes of the coolant in real time. Alternatively, measurements can be performed using an ERT (Electrical Resistance Tomography) system. ERT is a measurement method that uses the electrical properties of materials to measure temperature. It can be used for two-phase flow measurement in fast-flowing industrial pipelines. The ERT system can obtain the distribution and temperature information of the coolant within the pipeline.

[0073] The solutions provided in Embodiment 1 or Embodiment 2 above can be applied to various pressurized water reactor design schemes.

[0074] Example 3:

[0075] In this embodiment, a direct-insertion temperature measurement scheme is used in place of the upper chamber temperature measurement scheme in Embodiment 1 or Embodiment 2. This involves arranging a direct-insertion temperature monitoring device, such as a direct-insertion thermocouple, in the main pipeline to acquire the temperature, thus achieving the purpose of obtaining the average temperature of the hot section of the coolant. However, in compact reactor designs, due to the absence of a main pipeline, it is impossible to arrange direct-insertion thermocouples in the main pipeline. Therefore, the temperature measurement scheme of this embodiment is not applicable to compact reactors, while Embodiment 1 or Embodiment 2 can be applied to various pressurized water reactor designs.

[0076] Advantages of this invention:

[0077] This invention addresses the problem of hot-section coolant temperature monitoring failure in bypass temperature measurement designs when main pumps are shut down. By adding thermocouples to the integrated measurement components of the core measurement system, it achieves a reasonable and feasible method for monitoring the upper chamber coolant temperature. Furthermore, the hot-section coolant average temperature switching method proposed in this invention uses the bypass pipeline coolant temperature to represent the average hot-section coolant temperature under normal operating conditions, automatically switching to the upper chamber coolant temperature only when all main pumps are shut down. This approach thus accommodates both normal non-main pump shutdown conditions and all main pump shutdown conditions for hot-section coolant average temperature monitoring.

[0078] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A method for monitoring reactor coolant temperature, the reactor comprising a core, a primary loop connected to the core, the primary loop having a bypass pipe, and an upper chamber on the core, characterized in that, The reactor coolant temperature monitoring method includes: S1: Obtain the bypass pipe coolant temperature, upper chamber coolant temperature, and operating conditions of all main pumps in the primary loop; wherein, the primary loop is a loop of the reactor coolant in the reactor system; the bypass pipe is a hot section of a bypass in the primary loop; the bypass pipe coolant temperature is the temperature of the coolant measured in the hot section of the bypass; the upper chamber is a chamber located above the reactor core in the reactor pressure vessel of the reactor; the upper chamber coolant temperature is the temperature of the coolant measured in the upper chamber; the main pumps are located in the loop; S2: Select the bypass pipeline coolant temperature or the upper chamber coolant temperature as the reactor coolant temperature based on the operating conditions of all main pumps. Step S2 includes: When all the main pumps are operating normally, the bypass pipeline coolant temperature is selected as the reactor coolant temperature. When all the main pumps are in a stopped operating condition, the upper chamber coolant temperature is selected as the reactor coolant temperature.

2. The reactor coolant temperature monitoring method according to claim 1, characterized in that, In step S1, the step of obtaining the upper chamber coolant temperature includes: installing a monitoring device in the upper chamber and obtaining the upper chamber coolant temperature through the monitoring device.

3. The reactor coolant temperature monitoring method according to claim 1, characterized in that, In step S1, obtaining the bypass pipe coolant temperature, the upper chamber coolant temperature, and the operating conditions of all main pumps involves: obtaining the bypass pipe coolant temperature signal, the upper chamber coolant temperature signal, and the main pump operating condition signal. The main pump operating condition is obtained based on the main pump operating signal, and the main pump operating condition includes a normal operating signal and a pump stop signal. The bypass pipe coolant temperature is obtained based on the bypass pipe coolant temperature signal; The upper chamber coolant temperature is obtained based on the upper chamber coolant temperature signal; Step S2 is replaced by: when the main pump switches from the normal operation signal to the pump stop signal, the bypass pipeline coolant temperature signal is triggered to switch to the upper chamber coolant temperature signal, and the upper chamber coolant temperature is used as the reactor coolant temperature.

4. The reactor coolant temperature monitoring method according to claim 1, characterized in that, The bypass pipe coolant temperature is the coolant temperature of a certain hot section in the bypass pipe or the average of the coolant temperatures of multiple hot sections in the bypass pipe; the upper chamber coolant temperature is the coolant temperature at the center of the upper chamber or the average of the coolant temperatures at multiple locations in the upper chamber.

5. A reactor coolant temperature monitoring system, characterized in that, The reactor coolant temperature monitoring method according to any one of claims 1-4, wherein the monitoring system includes a monitoring device and a processing device, and the monitoring device is connected to the processing device; The processing device is used to receive data from the first temperature monitoring device, the second temperature monitoring device, and the main pump monitoring device, process the data, and output the data. The monitoring device includes: At least one first temperature monitoring device: for acquiring the temperature of the hot section coolant in the bypass pipeline; At least one second temperature monitoring device for acquiring the coolant temperature in the upper chamber; Main pump monitoring device: used to obtain the operating conditions of the main pump.

6. A reactor coolant temperature monitoring system according to claim 5, characterized in that, The second temperature monitoring device is located above the centerline of the pressure vessel inlet and outlet nozzles, and is positioned directly above the fuel assembly in the center of the reactor core.

7. A reactor coolant temperature monitoring system according to claim 6, characterized in that, When multiple second temperature monitoring devices are installed, the multiple second temperature monitoring devices are arranged around the center of the reactor core, and each second temperature monitoring device is located directly above its corresponding fuel assembly.

8. A reactor coolant temperature monitoring system according to claim 5, characterized in that, The second temperature monitoring device is connected to the integrated measurement component of the core measurement system.

9. A reactor coolant temperature monitoring system according to claim 5, characterized in that, The first temperature monitoring device is a temperature monitoring thermocouple and / or the second temperature monitoring device is a temperature monitoring thermocouple.

Images