Simulation calculation method for temperature rise of DCS (Distributed Control System) cabinet of nuclear power plant during fire smudging period, medium and equipment

Abstract

The invention discloses a nuclear power plant DCS cabinet temperature rise simulation calculation method, a medium and equipment during a fire smoke period, and the method comprises the steps: building a DCS cabinet model during the fire period, obtaining the external environment temperature t2 of the DCS cabinet, and obtaining the total heat load value phi 0 of the DCS cabinet; according to a calculation formula of convective heat dissipation heat phi 1 of the DCS cabinet; according to a calculation formula of the radiation heat dissipation heat phi 2 of the DCS cabinet; according to a calculation formula of conduction heat dissipation heat phi 3 of the DCS cabinet; and calculating the highest temperature t1 in the DCS cabinet according to phi 0 = phi 1 + phi 2 + phi 3. According to the method provided by the invention, the highest internal temperature of the smoked DCS cabinet during the fire disaster is obtained through modeling and calculation, so that whether the DCS cabinet and internal equipment thereof are damaged during the fire disaster can be accurately judged, and the DCS cabinet can work safely and reliably after the fire disaster is fully demonstrated. And the influence of huge progress and cost on an engineering project caused by overall replacement of the DCS cabinet is avoided.

Description

Technical Field

[0001] This invention relates to the field of nuclear power technology, and in particular to a method, medium, and equipment for simulating the temperature rise of a nuclear power plant's DCS cabinet during fire smoke exposure. Background Technology

[0002] When a fire occurs at a power plant, large amounts of hot smoke and dust fill the air, causing varying degrees of damage to the internal components of numerous DCS cabinets within the plant. Technical specifications stipulate that the operating temperature range for DCS cabinets is 0℃ to 55℃, while the operating temperature for PCB boards is typically between 10℃ and 80℃. Therefore, during a fire, the maximum operating temperature of the cabinets can easily be exceeded, leading to damage and unusability of the internal equipment.

[0003] Because there is no means to continuously monitor the temperature inside the cabinet, it is impossible to know the temperature rise process inside the cabinet during the fire smoke. As the party responsible for the cabinet, the DCS supplier can only make a subjective judgment by observing the surface smoke contamination of the equipment inside the cabinet. It is easy to conclude that all contaminated cabinets are unusable and need to be completely replaced to ensure their availability.

[0004] However, some of the cabinets were only affected by smoke and were not directly exposed to the flames, making them potentially reusable. However, there is currently a lack of methods to know the internal temperature of the cabinets during the smoke exposure period, making it impossible to accurately determine whether the internal temperature of the cabinets exceeded their operating temperature range during the fire, and consequently, whether the cabinets can be reused. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method, medium and equipment for simulating the temperature rise of a nuclear power plant DCS cabinet during fire smoke exposure.

[0006] The technical solution adopted by this invention to solve its technical problem is: to construct a method for simulating and calculating the temperature rise of a nuclear power plant DCS cabinet during fire smoke exposure, including the following steps: Establish a DCS cabinet model during the fire, obtain the external ambient temperature t2 of the DCS cabinet during the fire, and obtain the total heat load value Φ0 of the DCS cabinet. Based on the calculation formula of the convective heat dissipation Φ1 of the DCS cabinet, the relationship between the convective heat dissipation Φ1 and the highest temperature t1 inside the DCS cabinet and the ambient temperature t2 is obtained. Based on the calculation formula of radiative heat dissipation Φ2 of DCS cabinet, the relationship between radiative heat dissipation Φ2 and the highest temperature t1 inside DCS cabinet and the ambient temperature t2 is obtained. Based on the calculation formula of the heat dissipation Φ3 conducted by the DCS cabinet, the relationship between the heat dissipation Φ3 conducted by the DCS cabinet and the highest temperature t1 inside the DCS cabinet and the ambient temperature t2 is obtained. Based on Φ0=Φ1+Φ2+Φ3, the highest temperature t1 inside the DCS cabinet is calculated.

[0007] In some embodiments, the method for simulating the temperature rise of a nuclear power plant DCS cabinet during fire smoke exposure further includes the following steps: Obtain the size data of the DCS cabinet, and calculate the effective heat dissipation area A1 of the DCS cabinet based on the size data; The convective heat dissipation Φ1 = h * A1 * (t1 - t2), where h is the convective heat transfer coefficient.

[0008] In some embodiments, the value of h is 2.7142.

[0009] In some embodiments, according to Kirchhoff's laws, the formula for calculating the radiative heat dissipation Φ2 is: The radiative heat loss Φ2 = A1 * ε * (5.67 * ((T1 / 100)) 4 -(T2 / 100) 4 )), where ε is the blackness of the DCS cabinet surface, T1 is the absolute temperature value converted from the highest temperature t1 inside the DCS cabinet, and T2 is the absolute temperature value converted from the ambient temperature t2.

[0010] In some embodiments, the blackness ε ranges from 0.6 to 0.95.

[0011] In some embodiments, the method for simulating the temperature rise of a nuclear power plant DCS cabinet during fire smoke exposure further includes the following steps: Obtain the dimensional data of the DCS cabinet grounding bolts, and calculate the effective heat conduction area A2 and the bolt grounding length d based on the dimensional data of the DCS cabinet grounding bolts; The heat dissipation through conduction is Φ3 = k * A2 * (t1 - t2) / d, where k is the thermal conductivity coefficient.

[0012] In some embodiments, the value of k is 16.

[0013] In some embodiments, the ambient temperature t2 is the highest external temperature recorded during the fire.

[0014] The present invention also provides a computer-readable storage medium storing a computer program adapted for loading by a processor to execute the method for simulating temperature rise of a nuclear power plant DCS cabinet during fire fumigation as described in any of the above embodiments.

[0015] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the method for simulating the temperature rise of a nuclear power plant DCS cabinet during fire fumigation as described in any of the above embodiments by calling the computer program stored in the memory.

[0016] Implementing this invention has the following beneficial effects: The method for simulating the temperature rise of DCS cabinets in nuclear power plants during fire smoke exposure can accurately determine the internal temperature, especially the highest temperature, of DCS cabinets exposed to smoke during a fire by modeling and calculation. This allows for the accurate determination of whether the DCS cabinets and their internal equipment were damaged during the fire, enabling the reuse of DCS cabinets that have not suffered substantial damage. This fully demonstrates that DCS cabinets can operate safely and reliably after a fire, avoiding the significant impact on project schedule and costs caused by the complete replacement of DCS cabinets. Attached Figure Description

[0017] 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: Figure 1 This is a schematic diagram of a method for simulating the temperature rise of a nuclear power plant DCS cabinet during fire smoke exposure in some embodiments of the present invention; Figure 2 This is a schematic diagram of the heat dissipation mechanism of a natural heat dissipation DCS cabinet in some embodiments of the present invention. Figure 3 These are diagrams of the heat dissipation airflow of the DCS cabinet in some embodiments of the present invention; Figure 4 This is a schematic diagram of the location of temperature measuring points in the DCS cabinet in some embodiments of the present invention; Figure 5 This is a schematic diagram showing the actual measured temperature trend of the DCS cabinet in some embodiments of the present invention. Detailed Implementation

[0018] 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 "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" 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 this 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.

[0019] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" 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 components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," 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," "third," 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.

[0020] 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.

[0021] In one case, a battery fire at a nuclear power plant caused smoke to rise into the DCS cabinets through temporarily sealed cable openings, resulting in varying degrees of smoke contamination on numerous cabinets. Some cabinets triggered high-temperature alarms (the alarm threshold for the cabinet temperature sensors was 45°C). The internal temperature sensors, located at the upper ventilation openings of the cabinets, could only determine if the internal temperature exceeded the alarm threshold, but not the maximum temperature reached after exceeding it. Considering the potential irreparable damage to the DCS boards and other electronic equipment after exposure to excessively high temperatures, the DCS cabinet supplier recommended replacing all affected cabinets based solely on surface observations of the smoke-affected area. These cabinets would require remanufacturing, transportation to the site, and reinstallation and commissioning, taking at least 10 months. Therefore, there is an urgent need for a method to simulate and calculate the temperature rise of DCS cabinets during a fire-affected area, accurately determining whether most of the smoke-affected cabinets can be reused. In response, this invention provides a method for simulating the temperature rise of DCS cabinets in nuclear power plants during fire smoke exposure. This method can simulate and calculate the maximum temperature rise of DCS cabinets exposed to smoke during a fire, so as to accurately determine whether most of the smoke-exposed DCS cabinets can be reused.

[0022] like Figure 1 As shown, the simulation calculation method for the temperature rise of the DCS cabinet in the nuclear power plant during the smoke fumigation of the fire includes the following steps: S10. Establish a DCS cabinet model during the fire, obtain the external ambient temperature t2 of the DCS cabinet during the fire, and obtain the total heat load value Φ0 of the DCS cabinet.

[0023] S20. Based on the calculation formula of the convective heat dissipation Φ1 of the DCS cabinet, the relationship between the convective heat dissipation Φ1 and the highest temperature t1 inside the DCS cabinet and the ambient temperature t2 is obtained.

[0024] S30. Based on the calculation formula of the radiative heat dissipation Φ2 of the DCS cabinet, the relationship between the radiative heat dissipation Φ2 and the highest temperature t1 inside the DCS cabinet and the ambient temperature t2 is obtained.

[0025] S40. Based on the calculation formula of the heat dissipation Φ3 conducted by the DCS cabinet, the relationship between the heat dissipation Φ3 conducted by the DCS cabinet and the highest temperature t1 and ambient temperature t2 is obtained.

[0026] S50. Based on Φ0=Φ1+Φ2+Φ3, the highest temperature t1 inside the DCS cabinet is calculated.

[0027] In some embodiments, the method for simulating the temperature rise of a nuclear power plant DCS cabinet during fire smoke exposure further includes the following steps: obtaining the size data of the DCS cabinet, and calculating the effective heat dissipation area A1 of the DCS cabinet based on the size data of the DCS cabinet; convective heat dissipation Φ1=h*A1*(t1-t2), where h is the convective heat transfer coefficient, specifically, the value of h is 2.7142.

[0028] In some embodiments, in the method for simulating the temperature rise of the DCS cabinet in a nuclear power plant during fire smoke exposure, according to Kirchhoff's laws, in step S30, the formula for calculating the radiative heat dissipation Φ2 is: Radiative heat dissipation Φ2 = A1 * ε * (5.67 * ((T1 / 100)) 4 -(T2 / 100) 4 )), where T1 is the absolute temperature value converted from the highest temperature t1 inside the DCS cabinet, T2 is the absolute temperature value converted from the ambient temperature t2, and ε is the emissivity of the DCS cabinet surface (the emissivity is the ratio of the radiation power of an actual object to the radiation power of a blackbody at the same temperature), and the emissivity ε ranges from 0.6 to 0.95.

[0029] In some embodiments, the method for simulating the temperature rise of a nuclear power plant DCS cabinet during a fire smoke exposure also includes the following steps: obtaining the size data of the DCS cabinet ground bolts, calculating the effective heat conduction area A2 and the grounding length d of the bolts based on the size data of the DCS cabinet ground bolts; conducting heat dissipation Φ3=k*A2*(t1-t2) / d, where k is the heat conduction coefficient, specifically, the value of k is 16.

[0030] In some embodiments, in the simulation calculation method for temperature rise of DCS cabinet in nuclear power plant during fire smoke exposure, the ambient temperature t2 is the highest external temperature recorded during the fire.

[0031] The following section, with reference to a specific embodiment provided in this application, further elaborates on the method for simulating the temperature rise of a nuclear power plant DCS cabinet during fire smoke exposure.

[0032] like Figure 2 As shown, in this embodiment, a model is established based on the actual parameters of a commonly used DCS cabinet. The DCS cabinet in the model has dimensions of 2m*0.9m*0.45m (with door). The top of the DCS cabinet has ventilation holes, each 0.8 meters long and 0.25 meters wide. The DCS cabinet has no internal cooling fan and relies on natural cooling. Its cooling methods mainly include convection cooling between the cabinet walls and the outside air, radiation cooling from the cabinet walls, conduction cooling via bottom bolts, and cooling through the ventilation holes.

[0033] First, calculate the heat dissipated by the DCS cabinet through convection between the cabinet walls and the outside air. It should be noted that since the DCS cabinets are arranged close together, the areas on the sides of each DCS cabinet are adjacent to the sides of other DCS cabinets and are not included in the convection cooling calculation. The top surface of the DCS cabinet has large ventilation holes, and the bottom surface has cable holes that are sealed; these are also not included in the convection cooling calculation. Therefore, the effective heat dissipation area A1 of the DCS cabinet only includes the area of ​​the front and back walls of the cabinet. Specifically, in this embodiment, the effective heat dissipation area A1 = 2 * 0.9 * 2 = 3.6 m². 2 According to the formula for calculating convective heat loss, the convective heat loss Φ1 = h * A1 * (t1 - t2), where h is the convective heat transfer coefficient (unit: W / (m³)). 2 ×℃), and the value of h is 2.7142. Therefore, by using the above formula, we get Φ1=2.7142*3.6*(t1-t2)=9.77(t1-t2).

[0034] Next, calculate the heat radiated outwards by the DCS cabinet through its walls. It's understandable that the effective area of ​​the DCS cabinet radiating heat outwards is the same as the effective heat dissipation area A1 mentioned above.

[0035] According to Kirchhoff's laws, the formula for calculating the radiative heat loss Φ2 is: Radiative heat loss Φ2 = A1 * ε * (5.67 * ((T1 / 100)) 4 -(T2 / 100) 4 In this formula, T1 is the absolute temperature value converted from the highest temperature t1 inside the DCS cabinet, T2 is the absolute temperature value converted from the ambient temperature t2, and ε is the blackness of the DCS cabinet surface. Depending on the surface coating of the DCS cabinet, the blackness ε ranges from 0.6 to 0.95; in this embodiment, the blackness ε is 0.8. Therefore, using the above calculation formula, Φ2 can be calculated as 3.6 * 0.8 * 5.67 * ((T1 / 100)) 4 -(T2 / 100) 4 =16.33*((T1 / 100) 4 -(T2 / 100) 4 ).

[0036] Then, calculate the heat dissipation of the DCS cabinet through the bottom bolts. It should be noted that the radius of the grounding bolts at the bottom of the DCS cabinet is 0.006m, meaning the effective heat conduction area A2 = 4 * π * 0.006. 2The depth d is 0.005m. In this embodiment, according to the formula for calculating the heat dissipation through conduction, the heat dissipation through conduction is Φ3 = k * A2 * (t1 - t2) / d, where k is the thermal conductivity coefficient, specifically, the value of k is 16. Therefore, using the above formula, we obtain Φ3 = 16 * 4 * π * 0.006 2 *(t1-t2) / 0.005=1.45(t1-t2).

[0037] Finally, calculate the heat dissipated through the ventilation holes. It should be noted that, for example... Figure 3 As shown, during a fire, after the DCS cabinet is smoked, the filters of the ventilation holes inside the cabinet become clogged with soot (this is a gradual and slow process). Blue represents cold air, and red represents heat flow. Ultimately, this will cause the ventilation holes inside the DCS cabinet to fail in heat dissipation. Therefore, the calculation of heat dissipation from the ventilation holes is only applicable under normal operating conditions of the DCS cabinet and is used as a comparative reference value. The three heat dissipation methods mentioned above are all natural heat dissipation from the cabinet walls and body itself, unaffected by soot. Even after the ventilation channels are blocked during a fire, they can still dissipate heat. Therefore, when calculating the highest temperature t1 inside the DCS cabinet, only the first three heat dissipation methods are considered. Specifically, the ventilation hole area A3 = 0.8 * 0.25 = 0.2 m², and the formula for calculating the heat dissipation from the ventilation holes is: Φ4 = 74 * H * A3 * (t1 - t2) 1.25 Where H is the height difference between the air inlet and outlet, which is generally 2m. Therefore, using the above formula, we get Φ4 = 74 * 2 * 0.2 * (t1 - t2). 1.25 =29.6 (t1-t2) 1.25 .

[0038] Furthermore, in the model of this embodiment, the total heat load value Φ0 of the DCS cabinet is 650W, the ambient temperature t2 under normal operating conditions of the DCS cabinet is 26.8℃, and the ambient temperature t2 during fire smoke exposure is 32.35℃.

[0039] When the DCS cabinet is working normally (for reference), Φ0=Φ1+Φ2+Φ3+Φ4. Substituting the above data into the formula, the highest temperature inside the DCS cabinet, t1, can be calculated to be 47.6℃.

[0040] During a fire and smoke inhalation, the ventilation holes of the DCS cabinet cannot function properly. Φ0=Φ1+Φ2+Φ3. Substituting the corresponding data into the formula, we can calculate that the highest temperature inside the DCS cabinet is t1=52.6℃. This means that during the fire, the highest temperature inside the DCS cabinet affected only by smoke inhalation does not exceed the upper limit of its operating temperature range (0℃~55℃). Therefore, it can be determined that the DCS cabinet and its internal equipment were not damaged during the fire and can be reused.

[0041] To verify the reliability of this method, this embodiment also uses a test spare DCS cabinet for experimental verification. It should be noted that the various parameters of the test DCS cabinet are consistent with those of the aforementioned DCS cabinet model (i.e., the DCS cabinet model is established based on the model of the test DCS cabinet), and cards with a number equivalent to those in the field cabinet are inserted into the test DCS cabinet to create a near-realistic cabinet environment. Figure 4 As shown, three temperature sensors were placed in the test DCS cabinet. One was located at the ventilation outlet at the top of the DCS cabinet, serving as the first measuring point; the second was located at the highest temperature point inside the cabinet at the top of the DCS cabinet, serving as the second measuring point; and the third was located at the ventilation inlet at the bottom of the DCS cabinet, serving as the third measuring point. All cabinet doors were closed during the test.

[0042] Under normal power-on operating conditions, the ambient temperature t2 is 26.8℃. The test DCS cabinet dissipates heat through the ventilation holes. The measured cabinet temperatures are as follows: 35.2℃ at the first measuring point, 44.7℃ at the second measuring point, and 26.8℃ at the third measuring point.

[0043] To simulate a DCS cabinet's cooling channels being completely blocked after fire smoke exposure, the lower ventilation inlets and top ventilation holes of the test DCS cabinet were completely covered with paper. In this state, the test DCS cabinet completely lost its ventilation holes for heat dissipation, relying solely on air convection, radiation, and conduction within the cabinet itself. The ambient temperature t2 was adjusted to 32.35℃, and the test DCS cabinet was turned on. The test continued for 8 hours under these conditions, until the internal temperature reached equilibrium. Figure 5 As shown, MP1 is the first measuring point, MP2 is the second measuring point, and MP3 is the third measuring point. The measured data shows that the temperature at the first measuring point gradually approached the hot spot temperature inside the cabinet after the experiment began, stabilizing at approximately 48.0℃ after 4 hours; the temperature at the second measuring point stabilized at approximately 52℃ after 3 hours; and the temperature at the third measuring point rose slowly and continuously, eventually reaching a maximum of approximately 30℃.

[0044] Comparing the DCS cabinet temperature data measured in the experiment with the DCS cabinet temperature data calculated after the above modeling, it can be seen that the calculated temperature values ​​are basically consistent with the actual measured temperatures, verifying the effectiveness of the simulation calculation method for the temperature rise of nuclear power plant DCS cabinets during fire smoke exposure in this application.

[0045] This application provides a method for simulating the temperature rise of a nuclear power plant DCS cabinet during fire fumigation, analyzing the heat dissipation mechanism of the DCS cabinet. Based on the layout of the internal modules and equipment of the DCS cabinet, the heat dissipation path within the cabinet under fanless natural cooling conditions is analyzed. A calculation model for the internal temperature rise of the DCS cabinet is established. Natural heat dissipation of the DCS cabinet mainly includes four forms: air convection heat dissipation through the cabinet walls, radiation heat dissipation through the cabinet walls, conduction heat dissipation through bottom bolts, and heat dissipation through ventilation holes. Calculation formulas and related coefficients for each heat dissipation form are given. The simulation of the gradual loss of heat dissipation through ventilation holes in the DCS cabinet during fire fumigation is presented. Actual measurements of the internal temperature rise under normal operating conditions, partial loss of ventilation hole heat dissipation, and complete loss of ventilation hole heat dissipation are conducted. The temperature rise curve inside the DCS cabinet during fire fumigation is successfully reproduced. This strongly demonstrates that the DCS cabinet did not overheat during fire fumigation, indicating that the performance and lifespan of the modules and equipment inside the cabinet were not affected and can continue to be used normally.

[0046] The method for simulating the temperature rise of DCS cabinets in nuclear power plants during fire smoke exposure provided in this application, through modeling and calculation, determines the highest internal temperature of DCS cabinets exposed to smoke during a fire. This allows for accurate determination of whether the DCS cabinets and their internal equipment were damaged during the fire, enabling the reuse of DCS cabinets that have not suffered substantial damage. This fully demonstrates that DCS cabinets can operate safely and reliably after a fire, avoiding the significant impact on project schedule and costs caused by replacing the entire DCS cabinet, and has extremely high engineering value.

[0047] The present invention also provides a computer-readable storage medium storing a computer program adapted for loading by a processor to execute the method for simulating temperature rise of a nuclear power plant DCS cabinet during fire fumigation as described in any of the above embodiments.

[0048] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the method for simulating the temperature rise of a nuclear power plant DCS cabinet during fire fumigation as described in any of the above embodiments by calling the computer program stored in the memory.

[0049] The processor of this invention provides computing and control capabilities to support the operation of the entire system. It should be understood that, in the embodiments of this application, the processor may be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0050] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0051] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0052] 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 simulating and calculating the temperature rise of a nuclear power plant's DCS cabinet during a fire smoke attack, characterized in that, Includes the following steps: Establish a DCS cabinet model during the fire, obtain the external ambient temperature t2 of the DCS cabinet during the fire, and obtain the total heat load value Φ0 of the DCS cabinet. Based on the calculation formula of the convective heat dissipation Φ1 of the DCS cabinet, the relationship between the convective heat dissipation Φ1 and the highest temperature t1 inside the DCS cabinet and the ambient temperature t2 is obtained. Based on the calculation formula of radiative heat dissipation Φ2 of DCS cabinet, the relationship between radiative heat dissipation Φ2 and the highest temperature t1 inside DCS cabinet and the ambient temperature t2 is obtained. Based on the calculation formula of the heat dissipation Φ3 conducted by the DCS cabinet, the relationship between the heat dissipation Φ3 conducted by the DCS cabinet and the highest temperature t1 inside the DCS cabinet and the ambient temperature t2 is obtained. Based on Φ0=Φ1+Φ2+Φ3, the highest temperature t1 inside the DCS cabinet is calculated.

2. The method for simulating temperature rise of DCS cabinet in nuclear power plant during fire smoke exposure as described in claim 1, characterized in that, The method for simulating the temperature rise of the DCS cabinet in a nuclear power plant during fire smoke exposure also includes the following steps: Obtain the size data of the DCS cabinet, and calculate the effective heat dissipation area A1 of the DCS cabinet based on the size data; The convective heat dissipation Φ1 = h * A1 * (t1 - t2), where h is the convective heat transfer coefficient.

3. The method for simulating temperature rise of DCS cabinet in nuclear power plant during fire smoke exposure as described in claim 2, characterized in that, The value of h is 2.7142.

4. The method for simulating temperature rise of DCS cabinet in nuclear power plant during fire smoke exposure as described in claim 2, characterized in that, According to Kirchhoff's laws, the formula for calculating the radiative heat loss Φ2 is: The radiative heat loss Φ2 = A1 * ε * (5.67 * ((T1 / 100)) 4 -(T2 / 100) 4 )), where ε is the blackness of the DCS cabinet surface, T1 is the absolute temperature value converted from the highest temperature t1 inside the DCS cabinet, and T2 is the absolute temperature value converted from the ambient temperature t2.

5. The method for simulating temperature rise of DCS cabinet in nuclear power plant during fire smoke exposure as described in claim 4, characterized in that, The value of the blackness ε ranges from 0.6 to 0.

95.

6. The method for simulating temperature rise of DCS cabinet in nuclear power plant during fire smoke exposure as described in claim 4, characterized in that, The method for simulating the temperature rise of the DCS cabinet in a nuclear power plant during fire smoke exposure also includes the following steps: Obtain the dimensional data of the DCS cabinet grounding bolts, and calculate the effective heat conduction area A2 and the bolt grounding length d based on the dimensional data of the DCS cabinet grounding bolts; The heat dissipation through conduction is Φ3 = k * A2 * (t1 - t2) / d, where k is the thermal conductivity coefficient.

7. The method for simulating temperature rise of DCS cabinet in nuclear power plant during fire smoke exposure as described in claim 6, characterized in that, The value of k is 16.

8. The method for simulating temperature rise of nuclear power plant DCS cabinets during fire smoke exposure according to any one of claims 1 to 7, characterized in that, The ambient temperature t2 is the highest external temperature recorded during the fire.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program adapted for loading by a processor to execute the method for simulating temperature rise of a nuclear power plant DCS cabinet during fire fumigation as described in any one of claims 1 to 8.

10. A computer device, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the method for simulating the temperature rise of a nuclear power plant DCS cabinet during fire fumigation as described in any one of claims 1 to 8 by calling the computer program stored in the memory.

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