Heat flow density test system and method
By designing a heat flow density test system including centrifugal pump, regulating valve, test body, flowmeter and measuring device, the problems of equipment burning risk and unstable thermal parameters in low-flow heat flow density test are solved, and efficient and reliable test results are achieved.
Patent Information
- Application Number
- CN202411693908.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-03-28
AI Technical Summary
At this stage, the low-flow heat flow density test technology has the problems of risk of equipment burning, unstable thermal parameters, low test efficiency and low data quality. The implementation method lacks operational experience and complex processes, and the feedback response is slow.
A heat flow density test system is designed, including a centrifugal pump, a regulating valve, a test body, a flowmeter and a measuring device. The test working fluid is provided through a centrifugal pump. The regulating valve controls the flow rate within the range of 200kg/(m2·s) to 1300kg/(m2·s). The flowmeter monitors the flow rate, the measuring device measures the heat flow density, and controls the temperature and pressure through the preheater and the voltage regulator.
Effective tests of low flow heat flow density are achieved, testing efficiency is improved, equipment burning risk is reduced, and the reliability and accuracy of test data are enhanced.
Smart Images
Figure CN119724642A_ABST
Abstract
Description
Technical Field
[0001] The present application mainly relates to the field of nuclear power technology, and in particular to a heat flux density test system and method. Background Art
[0002] The heat exchange capacity between the fuel cladding surface and the core coolant directly affects the safe and stable operation of the nuclear reactor. When the heat flux density on the fuel cladding surface exceeds the critical heat flux (CHF), a boiling crisis will occur, causing a rapid decrease in heat transfer capacity and a sudden rise in the surface temperature of the fuel cladding, which directly threatens the integrity of the fuel cladding and the safety of the nuclear reactor. Therefore, CHF is an important restrictive thermal parameter related to nuclear reactor safety.
[0003] The CHF test is considered by the industry to be the most critical test in the development process of pressurized water reactor fuel assemblies at this stage. In order to avoid damage to fuel assemblies, pressurized water reactors require that the core cannot deviate from nucleate boiling (a common phenomenon that causes heat transfer deterioration under low vapor content conditions) under normal operation or medium-frequency accident conditions (i.e., Class I and Class II conditions), and CHF is used as a parameter to determine whether the core will deviate from nucleate boiling. The CHF test of fuel assemblies is mainly used to obtain the heat flux density of a specific type of fuel assembly under certain thermal-hydraulic conditions.
[0004] At present, the development or verification of all CHF relationships used for safety certification of pressurized water reactor nuclear power plants still relies on the CHF test data of the full-length fuel bundle. Compared with the "high flow, high pressure" operating environment of large reactor fuel assemblies such as CAP1000 and CAP1400, the integrated heating reactor adopts full natural circulation, which makes the core likely to have a lower flow under a small number of special conditions. The characteristics of "low flow, low pressure" (the CHF test defines low pressure below 10MPa and below 1300kg / (m 2 ·s) hereinafter defined as low flow) affects the mechanism and type of CHF occurrence, thus posing a challenge to the CHF test technology. In addition, under the low-flow CHF test conditions, the gas content at the outlet of the test body is high, and the temperature feedback speed is slow. The vaporization causes a large change in the volume of the coolant, which will cause blockage of the channel flow field and may lead to further vaporization, forming a positive feedback. At this time, if the test personnel are inexperienced and fail to take timely action, the test body, preheater and other equipment may be burned, increasing the risk of the test. In addition, the various thermal parameters in the test device are unstable and difficult to accurately control during the test, which seriously affects the test efficiency and test data quality.
[0005] Therefore, in order to meet the needs of low-flow CHF tests, it is necessary to modify the temperature, flow, and pressure measurement and control equipment for applicability. However, the current implementation methods for low-flow CHF tests of fuel assemblies at home and abroad lack operating experience, and the implementation process is complicated and the feedback response is slow, which seriously affects the safety and operability of the test. Summary of the invention
[0006] The technical problem to be solved by the present application is to provide a heat flux density test system and method, which can effectively test low-flow heat flux density and further improve the test efficiency of low-flow heat flux density.
[0007] In order to solve the above technical problems, the present application provides a heat flux density test system, comprising: a centrifugal pump, suitable for providing a test medium for the test system, the centrifugal pump comprising a first end of the centrifugal pump and a second end of the centrifugal pump; a regulating valve, the regulating valve is suitable for adjusting the flow rate of the test medium, wherein the flow rate is 200kg / (m 2 ·s)~1300kg / (m 2 ·s); a test body, a first end of the body and a second end of the body, the first end of the body is connected to the regulating valve, and the second end of the body is connected to the centrifugal pump; a flow meter, one end of the flow meter is connected to the second end of the centrifugal pump, and the other end of the flow meter is connected to the regulating valve, and the flow meter is suitable for monitoring the flow rate of the test working fluid in the test body; a measuring device, the measuring device is connected to the test body and is suitable for measuring the heat flux density of the test body.
[0008] Optionally, the regulating valve includes a manual valve and / or an electric valve.
[0009] Optionally, the measuring device comprises a thermocouple.
[0010] Optionally, the test system further comprises a preheater, wherein the preheater is connected to the first end of the body, and the preheater is suitable for heating the test working fluid flowing into the test body to a first temperature.
[0011] Optionally, the first temperature is 50°C to 300°C.
[0012] Optionally, the test system further comprises a pressure stabilizer, wherein the pressure stabilizer is connected to the second end of the centrifugal pump, and the pressure stabilizer is suitable for stabilizing the pressure of the test system when the regulating valve adjusts the flow of the test working fluid.
[0013] Optionally, the pressure of the test system is 6MPa(a) to 14.5MPa(a).
[0014] Optionally, the test system further comprises a spray valve, one end of which is connected to the first end of the centrifugal pump and the other end of which is connected to the regulator, and is suitable for controlling the pressure of the test system.
[0015] In order to solve the above technical problems, the present application provides a heat flux density test method, which is applicable to the heat flux density test system as described above, wherein the test system includes a test body, and is characterized in that the test method includes: providing a test medium to the test system through the centrifugal pump, wherein the centrifugal pump includes a first end of the centrifugal pump and a second end of the centrifugal pump; adjusting the flow rate of the test medium through the regulating valve, wherein the flow rate is 200kg / (m 2 ·s)~1300kg / (m 2 ·s), one end of the regulating valve is connected to one end of the flow meter; the flow rate of the test medium in the test body is monitored by the flow meter, wherein one end of the flow meter is connected to the second end of the centrifugal pump; the heat flux density of the test body is measured by the measuring device, wherein the measuring device is connected to the test body.
[0016] Optionally, the regulating valve includes an electric valve, and the test method adjusts the flow rate of the test working fluid by adjusting the throttling resistance of the electric valve.
[0017] Compared with the prior art, the present invention provides the test fluid of the test system through a centrifugal pump and adjusts the valve to control the flow rate of the test fluid, so that the flow rate of the test fluid is controlled at 200 kg / (m 2 ·s)~1300kg / (m 2 ·s), so that the flow rate of the test fluid passing through the test body is low flow rate, and further the flow meter is used to monitor the flow rate of the test fluid in the test body, so that the test fluid in the test body can be stabilized within the low flow rate range, which is convenient for the measuring device to measure the heat flux density of the test body, thereby obtaining the heat flux density of the test body at low flow rate. In addition to using a regulating valve to control the flow rate of the test system 10, the present application also controls the temperature and pressure of the test system 10 through a preheater and a stabilizer, so that the entire test system is closer to the internal conditions of a real nuclear reactor, and an effective test of low flow heat flux density is achieved, further improving the test efficiency of low flow heat flux density. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings are included to provide a further understanding of the present application. They are included and constitute a part of the present application. The accompanying drawings illustrate embodiments of the present application and together with the present specification serve to explain the principles of the present application. In the accompanying drawings:
[0019] Figure 1This is a schematic diagram of the structure of a heat flux test system in one embodiment of the present application;
[0020] Figure 2 It is a schematic flow chart of a heat flux test method in one embodiment of the present application. DETAILED DESCRIPTION
[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for the description of the embodiments. Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. Unless it is obvious from the language environment or otherwise explained, the same reference numerals in the figures represent the same structure or operation.
[0022] As shown in this application and claims, unless the context clearly indicates an exception, the words "a", "an", "an" and / or "the" do not refer to the singular and may also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.
[0023] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.
[0024] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.
[0025] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.
[0026] In addition, it should be noted that the use of words such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above words have no special meaning and cannot be understood as limiting the scope of protection of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant parts of the description of this article. In addition, it is required to understand this application not only by the actual terms used, but also by the meaning implied by each term.
[0027] This application refers to Figure 1 A heat flux test system 10 (hereinafter referred to as "test system 10") is shown, and the test system 10 mainly includes a centrifugal pump 11, a regulating valve 12, a test body 13, a flow meter 14 and a measuring device (not shown). Specifically, the centrifugal pump is mainly used to provide a test medium, such as water, for the test system. In this embodiment, the centrifugal pump includes a first end A of the centrifugal pump and a second end B of the centrifugal pump.
[0028] Furthermore, the regulating valve 12 is suitable for regulating the flow rate of the test medium, so that the flow rate of the test medium in the test system 10 is within the range of 200 kg / (m 2 ·s)~1300kg / (m 2 ·s), for example 200kg / (m 2 ·s)、400kg / (m 2 ·s)、600kg / (m 2 ·s)、800kg / (m 2 ·s)、1000kg / (m 2 ·s)、1200kg / (m2 ·s) and 1300kg / (m 2 ·s). In this embodiment, the regulating valve 12 preferably includes a manual valve 121 and an electric valve 122. The test system 10 can adjust the opening of the manual valve upstream of the test body 13 according to the test boundary before the test, and adjust the opening of the electric valve during the test to maintain the inlet flow of the test body 13 within the range of the target flow value.
[0029] In this embodiment, the test body 13 includes a first end C of the body and a second end D of the body. The first end C of the body is connected to the electric valve 122 in the regulating valve 12. Preferably, a preheater 16 is also included between the first end C of the body and the electric valve 122. The preheater 16 can be controlled by input voltage and heats the test fluid flowing into the test body to a first temperature, thereby achieving temperature control of the test system 10, making the temperature of the test fluid closer to the liquid temperature in a real nuclear reactor, and further improving the accuracy and reliability of the test. The second end D of the body is connected to the centrifugal pump 11. Exemplarily, the above-mentioned first temperature includes 50°C to 300°C, such as 50°C, 100°C, 150°C, 200°C, 250°C and 300°C.
[0030] On the other hand, the test system 10 also includes a flow meter 14 and a measuring device 15. One end of the flow meter 14 is connected to the second end B of the centrifugal pump, and the other end of the flow meter 14 is connected to the manual valve 121 in the regulating valve 14. The flow meter 14 can monitor the flow of the test fluid in the test body 13. The staff can better observe the flow of the test fluid in the test system 10 through the flow meter 14 to monitor whether the test fluid in the test body 13 meets the low flow requirement, thereby better measuring the heat flux density value of the test body 13 at low flow.
[0031] Furthermore, the test system 10 also includes a measuring device (not shown), which is connected to the test body 13 and is suitable for measuring the heat flux density of the test body 13 to obtain the heat flux density value of the test system 10 under low flow conditions, thereby achieving effective testing of low flow heat flux density and further improving the test efficiency of low flow heat flux density. Exemplarily, the measuring device includes a thermocouple.
[0032] In the present embodiment, the test system 10 also includes a pressure stabilizer 17 and a spray valve 18. The pressure stabilizer 17 is connected to the second end B of the centrifugal pump and is suitable for stabilizing the pressure of the test system 10 when the regulating valve 12 adjusts the flow rate of the test medium. Exemplarily, the pressure stabilizer 17 stabilizes the pressure of the test system 10 at 6MPa(a) to 14.5MPa(a). One end of the spray valve 18 is connected to the first end A of the centrifugal pump, and the other end is connected to the pressure stabilizer 17, which is suitable for controlling the pressure of the test system. By setting the pressure stabilizer 17 and the spray valve 18, the pressure of the test system 10 can be stabilized when the regulating valve 12 is used to adjust the flow rate of the test body 14, so that the pressure state of the test system 10 is closer to the pressure state in a real nuclear reactor, further improving the experimental accuracy and reliability of the test system 10.
[0033] On the other hand, the present application further proposes a heat flux density test method 20, which is applicable to the heat flux density test system proposed in any embodiment of the present application, such as the above-mentioned test system 10. Figure 2 A schematic flow diagram of a heat flux test method 20 is shown, and a flow diagram is used in the present application to illustrate the operations performed by the system according to an embodiment of the present application. It should be understood that the preceding or following operations are not necessarily performed precisely in order. On the contrary, various steps may be processed in reverse order or simultaneously. At the same time, other operations may be added to these processes, or one or more operations may be removed from these processes. The heat flux test method 20 mainly includes the following steps.
[0034] S1: providing a test medium to the test system through a centrifugal pump, wherein the centrifugal pump comprises a first end of the centrifugal pump and a second end of the centrifugal pump;
[0035] S2: Adjust the flow rate of the test medium by adjusting the valve, where the flow rate is 200kg / (m 2 ·s)~1300kg / (m 2 ·s), one end of the regulating valve is connected to one end of the flow meter;
[0036] S3: monitoring the flow rate of the test medium in the test body by means of a flow meter, wherein one end of the flow meter is connected to the second end of the centrifugal pump;
[0037] S4: measuring the heat flux density of the test body by means of a measuring device, wherein the measuring device is connected to the test body.
[0038] Furthermore, the heat flux density test method 20 can adjust the flow rate of the test medium by adjusting the throttling resistance of the electric valve. During the test, the heat flux density test method 20 can make the ratio of the throttling resistance of the electric valve and the resistance of the test body within a certain range, thereby reducing the impact of flow fluctuations in the test body caused by resistance changes during low flow tests.
[0039] The present invention uses a centrifugal pump to provide the test fluid of the test system, and adjusts the valve to control the flow rate of the test fluid, so that the flow rate of the test fluid is controlled at 200kg / (m 2 ·s)~1300kg / (m 2 ·s), so that the flow rate of the test fluid passing through the test body is low flow, and further the flow meter is used to monitor the flow rate of the test fluid in the test body, so that the test fluid in the test body can be stabilized within the low flow range, which is convenient for the measuring device to measure the heat flux density of the test body, thereby obtaining the heat flux density of the test body at low flow. In addition to using a regulating valve to control the flow of the test system 10, the present application also controls the temperature and pressure of the test system 10 through a preheater and a voltage stabilizer, so that the entire test system is closer to the internal conditions of a real nuclear reactor, and an effective test of low flow heat flux density is achieved, further improving the test efficiency of low flow heat flux density.
[0040] The basic concepts have been described above. Obviously, for those skilled in the art, the above application disclosure is only an example and does not constitute a limitation of the present application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements and amendments to the present application. Such modifications, improvements and amendments are suggested in the present application, so such modifications, improvements and amendments still belong to the spirit and scope of the exemplary embodiments of the present application.
[0041] At the same time, the present application uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.
[0042] Similarly, it should be noted that in order to simplify the description of the disclosure of this application and thus help understand one or more application embodiments, in the above description of the embodiments of this application, multiple features are sometimes merged into one embodiment, figure or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than the features mentioned in the claims. In fact, the features of the embodiments are less than all the features of the single embodiment disclosed above.
[0043] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise specified, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may change according to the required features of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the setting of such numerical values is as accurate as possible within the feasible range.
[0044] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions may be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present application, they will fall within the scope of the claims of the present application.
Claims
1. A heat flux test system, characterized in that: include: A centrifugal pump, adapted to provide a test medium for the test system, the centrifugal pump comprising a centrifugal pump first end and a centrifugal pump second end; The regulating valve is suitable for adjusting the flow rate of the test medium, wherein the flow rate is 200 kg / (m 2 ·s)~1300kg / (m 2 s); A test body, a first end of the body and a second end of the body, the first end of the body is connected to the regulating valve, and the second end of the body is connected to the centrifugal pump; A flow meter, one end of which is connected to the second end of the centrifugal pump, and the other end of which is connected to the regulating valve, and the flow meter is suitable for monitoring the flow of the test medium in the test body; A measuring device is connected to the test body and is suitable for measuring the heat flux density of the test body.
2. The test system according to claim 1, characterized in that: The regulating valve includes a manual valve and / or an electric valve.
3. The test system according to claim 1, characterized in that: The measuring device comprises a thermocouple.
4. The test system according to claim 1, characterized in that: It also includes a preheater, which is connected to the first end of the body and is suitable for heating the test medium flowing into the test body to a first temperature.
5. The test system according to claim 4, characterized in that: The first temperature is 50°C to 300°C.
6. The test system according to claim 1, characterized in that: It also includes a pressure stabilizer, which is connected to the second end of the centrifugal pump and is suitable for stabilizing the pressure of the test system when the regulating valve adjusts the flow of the test working fluid.
7. The test system according to claim 6, characterized in that: The pressure of the test system is 6MPa(a) to 14.5MPa(a).
8. The test system according to claim 6, characterized in that: It also includes a spray valve, one end of which is connected to the first end of the centrifugal pump, and the other end of which is connected to the regulator, and is suitable for controlling the pressure of the test system.
9. A heat flux test method, applicable to the heat flux test system according to claims 1 to 8, wherein the test system comprises a test body, characterized in that: The test method includes: Providing a test medium to the test system through the centrifugal pump, wherein the centrifugal pump comprises a first end of the centrifugal pump and a second end of the centrifugal pump; The flow rate of the test medium is adjusted by the regulating valve, wherein the flow rate is 200 kg / (m 2 ·s)~1300kg / (m 2 s), one end of the regulating valve is connected to one end of the flow meter; Monitoring the flow rate of the test medium in the test body by means of the flow meter, wherein one end of the flow meter is connected to the second end of the centrifugal pump; The heat flux density of the test body is measured by the measuring device, wherein the measuring device is connected to the test body.
10. The test method according to claim 9, characterized in that The regulating valve includes an electric valve, and the test method adjusts the flow rate of the test medium by adjusting the throttling resistance of the electric valve.