Multi-rod-bundle critical heat flux density experimental device
By designing a multi-bar bundle critical heat flux density experimental device, which employs an inner shell and a pressure-bearing shell structure, experimental testing under high pressure conditions was achieved. This solved the problem that existing devices cannot be used in high-pressure environments, improved experimental safety and data accuracy, simplified the structure, and reduced costs.
Patent Information
- Application Number
- CN202520358655.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-28
- Publication Date
- 2026-02-27
- Estimated Expiration
- 2035-02-28
AI Technical Summary
Existing critical heat flux density experimental setups are not suitable for multi-bar bundle high-pressure environments, making it impossible to conduct effective experimental testing under high temperature and high pressure conditions.
Design a multi-rod bundle critical heat flux density experimental device, which adopts an inner shell and a pressure shell structure. Data is collected by non-uniform heating of heating rods and detection by lead-out pipes, combined with temperature sensors and pressure transmitters. The design eliminates the viewing window and simulates the actual operating conditions of a reactor.
It significantly improves the pressure resistance and safety of the experimental device, can accurately simulate reactor operation under high pressure conditions, provides high-quality CHF mechanism research data, simplifies the experimental structure and reduces costs.
Smart Images
Figure CN223955490U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to nuclear reactor thermal hydraulic experiment technical field, especially a kind of multi-rod bundle critical heat flux experimental device. BACKGROUND
[0002] Critical heat flux (CHF) refers to the maximum heat flux per unit area when the surface of heating element changes from nucleate boiling to film boiling in the boiling heat transfer process.Critical heat flux, as the most important parameter of reactor core thermal hydraulic performance, is directly related to the safety and economy of the core, and higher CHF value not only means that the core can carry higher output power, but also can significantly enhance its safety margin and expand the operating limits of the reactor.
[0003] Small modular reactor (SMR) has attracted widespread attention in recent years due to its modularity, flexibility and potential economy.However, there are significant differences between the existing small modular pressurized water reactor and large pressurized water reactor core thermal design, mainly in the aspects of low operating pressure, low core height, low natural circulation flow, unique fuel assembly layout design, different reactivity control methods, etc.For example, small reactor has low operating power, low pressure, low flow rate, short core height and more distorted power distribution, which will directly affect the two-phase thermal hydraulic parameter distribution in the fuel assembly, and further lead to the complexity of CHF research.The existing CHF research experimental device is usually low-pressure experiment for convenient observation of changes and opening of a visual window for bubble observation;However, under the actual operating conditions of high temperature and high pressure, the mechanism of CHF change is different from that in low-pressure environment, and the CHF mechanism model developed based on low-pressure experiment is not suitable for reactor operating conditions, and if the visual window design of existing low-pressure experimental equipment is used in high-pressure environment, the internal pressure is too high, which can easily lead to liquid leakage and failure to complete experimental detection. SUMMARY
[0004] In view of the deficiencies of the prior art, the technical problem to be solved by the utility model is to provide a multi-rod bundle critical heat flux experimental device to solve the problem that the existing critical heat flux experimental device cannot be applied to experimental research in high-pressure environment of multi-rod bundle.
[0005] In order to solve the above problems, the technical scheme adopted by the utility model is: a kind of multiple rod bundle critical heat flux density experimental device, including shell, heating rod, the shell includes first electrode cylinder, water inlet section, experimental section, water outlet section and second electrode cylinder in turn from left to right, and each section is sealedly connected by flange;The shell of water inlet section, experimental section, water outlet section includes inner shell and pressure-bearing shell, and the inner space of inner shell forms flow channel, and the interlayer between inner shell and pressure-bearing shell is formed;The heating rod is provided with multiple and located in flow channel, and heating rod sealing disc for supporting and limiting heating rod is arranged in water inlet section and water outlet section, and single heating rod is fixedly connected together by multiple pipes with different wall thickness;Heating rod extends to first electrode cylinder and second electrode cylinder at two ends respectively;And first electrode cylinder and second electrode cylinder are provided with electrically conductive column for heating heating rod along the axial direction of shell, and electrically conductive column extends to the outside of shell;Experimental section is provided with lead-out pipe along the axial direction of shell on both sides, and is connected with temperature sensor and pressure transmitter respectively;Lead-out pipe is vertically arranged with the axial direction of shell, the detection end of lead-out pipe is attached to the outer wall of inner shell, and the measurement end of lead-out pipe extends to the outside of pressure-bearing shell.
[0006] The technical principle generated by the scheme is: deionized water is injected into flow channel through water inlet section and water outlet section, then water inlet and outlet are closed, and heating rod is unevenly heated through certain side electrically conductive column. Since the heating rod of the scheme is composed of multiple pipes with different wall thickness, according to calculation power formula P=U2 / R and resistance law R=ρL / S, the controllable factor in the device is S cross-sectional area, thereby affecting resistance, and then affecting heat generation through resistance;Different wall thickness leads to different resistance, different resistance leads to different heat generation, and then uneven heating of heating rod is realized. The temperature change and pressure change of experimental section are detected by sensor respectively, when the wall temperature ramp rate of inner tube is greater than or equal to the set threshold, or the wall temperature exceeds the material safety limit, it indicates that the critical point is reached.
[0007] The beneficial effects generated by the scheme are: by setting inner shell and pressure-bearing shell, the pressure-bearing capacity of experimental device is improved, and the pressure-bearing capacity and safety of experimental device are significantly improved, so that the experimental requirements under high pressure condition can be met, and the actual operating conditions of reactor can be simulated more accurately, to provide high-quality data support for CHF mechanism research. The design of visible window is cancelled, the wall temperature change and pressure change in temperature sensor and pressure transmitter are detected and data are collected by adopting lead-out pipe, and then the collected data are used to study the action mechanism of CHF.
[0008] Further, the outer wall of the inner shell of the experimental section is provided with annular groove, and flow channel pressure ring is detachably connected at the annular groove, and the detection end of the lead-out pipe extends through the flow channel pressure ring and touches the outside of the inner shell. The flow channel pressure ring can limit and support the lead-out pipe, and assist the pressure transmitter to detect pressure.
[0009] Further, the internal cavity of the experimental section is a square cavity. The square cavity is more in line with the internal structure of the SMR, and the detection data obtained can better reflect the CHF mechanism of the SMR.
[0010] Further, the heating rods are provided in four, and are uniformly distributed in two rows and two columns. The 2X2 distributed heating rod bundle is simpler than the existing 5X5 rod bundle structure, is reduced from 25 to 4, and significantly simplifies the structure of the experimental device; the interaction between the heating rods is reduced, and the complexity of the experimental design and operation is reduced. The experimental time is short, the efficiency is high, and the cost of the thermal hydraulic experiment can be reduced.
[0011] Further, the lead-out pipes are provided in multiple groups, one group of the lead-out pipes is provided with two lead-out pipes and is distributed on both sides of the shell axis, the two lead-out pipes are a temperature detection pipe and a pressure detection pipe respectively, the detection end of the pressure detection pipe penetrates through the inner shell and is in communication with the inside of the flow channel, a pressure transmitter is installed at the detection end of the pressure detection pipe and makes the deionized water in the flow channel flow through the detection joint of the pressure transmitter; the temperature sensor is installed at the detection end of the temperature sensor and makes the temperature sensor contact the outer wall of the inner shell; the lead-out pipes in the same group are located on the same straight line, and the detection ends of the two lead-out pipes in the same group are connected to the same flow channel pressure tapping ring. For the experimental section on the same cross section, the temperature and pressure changes are monitored by the two lead-out pipes in one group respectively, and the monitoring of multiple points is realized by the multiple groups, the amount of data collected is large, and the CHF action mechanism can be better summarized through the experimental data.
[0012] Further, the detection end of the lead-out pipe is an outwardly convex outer arc surface, and the contact surface between the outer wall of the inner shell and the detection end of the lead-out pipe is an inwardly concave inner arc surface matched with the outer arc surface. The outer arc surface and the inner arc surface can increase the contact area between the lead-out pipe and the outer wall of the inner shell.
[0013] Further, the experimental section is provided with multiple segments, the segments are sealingly connected through flanges, and one inner shell and a pressure-bearing shell form one segment. The test section is divided into multiple segments, which facilitates the loading and unloading and transportation of the experimental equipment. BRIEF DESCRIPTION OF DRAWINGS
[0014] Fig. 1 It is a schematic diagram of an embodiment of the utility model.
[0015] Fig. 2 It is a schematic diagram of the structure of the experimental section.
[0016] Fig. 3 It is a schematic diagram of the structure of the lead-out pipe.
[0017] Fig. 4 It is a cross-sectional view of the utility model along the shell axis.
[0018] Fig. 5 It is a sectional view of the lead-out pipe. Detailed Implementation
[0019] The following detailed description illustrates the specific implementation method:
[0020] The reference numerals in the accompanying drawings include: shell 1, first electrode cylinder 11, water inlet section 12, experimental section 13, water outlet section 14, second electrode cylinder 15, inner shell 16, pressure bearing shell 17, flow channel pressure tapping ring 18, annular groove 19, lead-out pipe 2, detection end 21, temperature detection tube 22, pressure detection tube 23, water inlet pipe 3, water outlet pipe 4, conductive column 5, heating rod 6, heating rod sealing plate 61.
[0021] The basics are as follows: Figs. 1-3 As shown, a multi-rod bundle critical heat flux density experimental device includes a shell 1 and heating rods 6. The shell 1 includes a first electrode cylinder 11, a water inlet section 12, an experimental section 13, a water outlet section 14, and a second electrode cylinder 15 arranged sequentially from left to right, and the sections are connected by flange seals. The shell 1 of the water inlet section 12, experimental section 13, and water outlet section 14 includes an inner shell 16 and a pressure-bearing shell 17. The internal space of the inner shell 16 forms a flow channel, and the inner shell 16 and the pressure-bearing shell 17 form a sandwich. Multiple heating rods 6 are provided and located in the flow channel. The water inlet section 12 and the water outlet section 14 are each provided with a heating rod 6 sealing plate for supporting, limiting, and sealing the heating rods 6. The water inlet section 12 is connected to a water inlet pipe 3 with a water inlet valve, and the water inlet pipe 3 is connected to the water inlet section 12 by a flange seal. The water outlet section 14 is connected to a water outlet pipe 4 with a water outlet valve, and the water outlet pipe 4 is connected to the water outlet section 14 by a flange.
[0022] The heating rod 6 extends to the first electrode cylinder 11 and the second electrode cylinder 15 at both ends, respectively. Both the first electrode cylinder 11 and the second electrode cylinder 15 are provided with conductive posts 5 along the axial direction of the shell 1 for heating the heating rod 6, and the conductive posts 5 extend to the outside of the shell 1, heating the heating rod 6 through the conductive posts 5. In this embodiment, there are four heating rods 6, evenly distributed in two rows and two columns. Using a 2x2 distribution of the heating rods 6 bundle is simpler than the existing 5x5 rod bundle structure, reducing the number of rods from 25 to 4, significantly simplifying the structure of the experimental apparatus; reducing the interaction between the heating rods 6, and lowering the complexity of experimental design and operation. The experiment is shorter, more efficient, and can reduce the cost of thermal hydraulic experiments.
[0023] The outer wall of the inner shell 16 of the experimental section 13 is provided with a ring groove 19, and a flow channel pressure ring 18 is detachably connected at the ring groove 19; the experimental section 13 is provided with lead-out pipes 2 on both sides along the axial direction of the shell 1, the lead-out pipes 2 are arranged vertically to the axial direction of the shell 1, and the experimental section 13 is provided with two sections, each of which is provided with three groups of lead-out pipes 2. One group of lead-out pipes 2 is provided with two lead-out pipes 2 distributed on both sides of the axial line of the shell 1, and the two lead-out pipes 2 are respectively a temperature detection pipe 22 and a pressure detection pipe 23; the detection end 21 of the pressure detection pipe 23 penetrates through the inner shell 16 and is in communication with the inside of the flow channel; a pressure transmitter is installed at the detection end 21 of the pressure detection pipe 23 and makes the deionized water in the flow channel flow through the detection joint of the pressure transmitter; a temperature sensor is installed at the temperature sensor detection end 21 and makes the temperature sensor contact the outer wall of the inner shell 16; the lead-out pipes 2 in the same group are located on the same straight line, and the detection ends 21 of the two lead-out pipes 2 in the same group are connected to the same flow channel pressure ring 18. The temperature sensor adopts a thermocouple sensor, and the pressure transmitter adopts an EJA pressure transmitter.
[0024] The detection end 21 of the lead-out pipe 2 is an outwardly convex outer arc surface, and the contact surface between the outer wall of the inner shell 16 and the detection end 21 of the lead-out pipe 2 is an inwardly concave inner arc surface matched with the outer arc surface. By arranging the outer arc surface and the inner arc surface, the contact area between the lead-out pipe 2 and the outer wall of the inner shell 16 can be increased.
[0025] The above is only an embodiment of the present application, and the specific structure and characteristics of the scheme are not described in detail. It should be pointed out that for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should also be regarded as the protection scope of the present application, and these will not affect the effect and practicality of the present application. The protection scope of the present application should be subject to the content of its claims, and the specific implementation mode and the like in the specification can be used to explain the content of the claims.
Claims
1. A multi-rod bundle critical heat flux experiment apparatus, characterized by: The application relates to a heating rod type ion exchange water quality testing device, which comprises a shell, a heating rod, the shell comprises a first electrode cylinder, a water inlet section, an experimental section, a water outlet section and a second electrode cylinder arranged in sequence from left to right, and the sections are sealingly connected through flanges; the shells of the water inlet section, the experimental section and the water outlet section comprise an inner shell and a pressure-bearing shell, the inner space of the inner shell forms a flow channel, and a sandwich is formed between the inner shell and the pressure-bearing shell; the heating rod is provided with a plurality of heating rods arranged in the flow channel, the water inlet section and the water outlet section are each provided with a heating rod sealing disc for supporting and limiting the heating rod, a single heating rod is fixedly connected by a plurality of pipes with different wall thicknesses, the two ends of the heating rod extend to the first electrode cylinder and the second electrode cylinder respectively, the first electrode cylinder and the second electrode cylinder are each provided with a conductive column for heating the heating rod along the axial direction of the shell, and the conductive column extends to the outside of the shell; the experimental section is provided with lead-out pipes on both sides along the axial direction of the shell and is used for mounting temperature sensors and pressure transmitters; the lead-out pipes are arranged vertically to the axial direction of the shell, the detection end of the lead-out pipe is in contact with the outer wall of the inner shell, and the measurement end of the lead-out pipe extends to the outside of the pressure-bearing shell.
2. The multi-rod bundle critical heat flux experiment apparatus of claim 1, wherein: The outer wall of the inner shell of the experimental section is provided with a ring groove, and a flow channel pressure taking ring is detachably connected at the ring groove; the detection end of the lead-out pipe extends through the flow channel pressure taking ring and is in contact with the outside of the inner shell.
3. The multi-rod bundle critical heat flux experiment apparatus of claim 1, wherein: The internal cavity of the experimental section is a square cavity.
4. The multi-rod bundle critical heat flux experiment apparatus of claim 1, wherein: The heating rod is provided with four heating rods which are uniformly distributed in two rows and two columns.
5. The multi-rod bundle critical heat flux experiment apparatus of claim 2, wherein: The lead-out pipes are provided with a plurality of groups, one group of lead-out pipes is provided with two lead-out pipes which are distributed on both sides of the axial line of the shell, the two lead-out pipes are a temperature detection pipe and a pressure detection pipe respectively, the detection end of the pressure detection pipe is communicated with the inside of the flow channel through the inner shell, a pressure transmitter is mounted on the detection end of the pressure detection pipe and makes the deionized water in the flow channel flow through the detection joint of the pressure transmitter; the temperature sensor is mounted on the detection end of the temperature sensor and makes the temperature sensor in contact with the outer wall of the inner shell; the lead-out pipes in the same group are located on the same straight line, and the detection ends of the two lead-out pipes in the same group are connected to the same flow channel pressure taking ring.
6. The multi-rod bundle critical heat flux experiment apparatus of claim 2, wherein: The detection end of the lead-out pipe is an outwardly convex outer arc surface, and the contact surface between the outer wall of the inner shell and the detection end of the lead-out pipe is an inwardly concave inner arc surface matched with the outer arc surface.
7. The multi-rod bundle critical heat flux experiment apparatus of claim 1, wherein: The experimental section comprises a plurality of subsections, the subsections are sealingly connected through flanges, and one inner shell and one pressure-bearing shell form one subsection.