A narrow gap annular flow channel experimental device

Abstract

This utility model relates to the technical field of fluid heat transfer experimental equipment, and provides a narrow-slit annular flow channel experimental device, including: an adjustable narrow-slit flow channel module, a cold water circulation system, and a hot water circulation system; the adjustable narrow-slit flow channel module includes: multiple sets of experimental flow channels; each experimental flow channel includes: an outer tube and an inner tube arranged concentrically; a narrow slit is formed between the outer tube and the inner tube; the inner tube diameters of different experimental flow channels are different; a cold water inlet is provided at one end of the outer tube, and a cold water outlet is provided at the other end; the cold water inlet and cold water outlet are connected to the cold water circulation system; a hot water inlet is provided at one end of the inner tube, and a hot water outlet is provided at the other end; the hot water inlet and hot water outlet are connected to the hot water circulation system. This utility model meets the comparative experimental needs of flow channels with different gaps and different materials, and can study the fluid resistance and heat transfer characteristics under different conditions, providing rich experimental data for related research.

Description

Technical Field

[0001] This utility model relates to the technical field of fluid heat transfer experimental equipment, and in particular to an experimental device for a narrow-slit annular flow channel. Background Technology

[0002] Driven by the "dual carbon" goals and the Industry 4.0 strategy, narrow-slit annular flow channels (0.1-3mm gap) have become core thermal components in key fields such as nuclear reactor fuel rod cooling, new energy vehicle fuel cells, and chemical microreactors due to their ultra-high heat transfer efficiency (heat exchange area per unit volume can reach 5-8 times that of conventional pipes). However, research on their microscale flow and heat transfer mechanisms has long been limited by the technical bottleneck of experimental devices, which has largely hindered breakthroughs in their industrial applications.

[0003] Narrow-slit annular flow channel experimental setups are primarily used to simulate fluid flow and heat transfer within narrow-slit annular flow channels, providing experimental data for related research. These setups typically include a flow channel structure and a circulation system for transporting the fluid, attempting to observe the heat transfer and resistance characteristics within the flow channel by allowing fluids of different temperatures or properties to flow within it.

[0004] Traditional narrow-slit annular flow channel experimental setups have several drawbacks. First, they are limited in function and application, failing to meet industry demands for multi-scale, full-flow-state, and dual-function experimental data, thus restricting the in-depth research and application of narrow-slit annular flow channels across multiple fields. Second, the flow channel structure of traditional setups suffers from poor stability, potentially leading to concentricity deviations that cause errors in fluid flow and heat transfer characteristic measurements, affecting experimental accuracy and failing to provide reliable basic data. Third, traditional setups are inconvenient to operate and maintain; the pipes are mostly fixed connections, hindering cleaning, replacement, and maintenance, reducing the flexibility and practicality of the experimental setup. Finally, traditional setups pose safety risks; some setups lack explosion-proof piping and other safety designs, resulting in a high risk of leakage when handling high-temperature or high-pressure fluids, threatening the safety of the experimental process. Utility Model Content

[0005] This invention addresses the technical problems of traditional narrow-slit annular flow channel experimental devices, which have limited functionality and applicability, failing to meet the needs of multi-condition comparative experiments; unstable flow channel structure affecting experimental accuracy; and inconvenient operation and maintenance. It proposes a narrow-slit annular flow channel experimental device to meet the comparative experimental needs of flow channels with different gaps and materials, enabling the study of fluid resistance and heat transfer characteristics under different conditions, and providing abundant experimental data for related research.

[0006] This utility model provides a narrow slit annular flow channel experimental device, including: an adjustable narrow slit flow channel module, a cold water circulation system and a hot water circulation system;

[0007] The adjustable narrow slit flow channel module includes: multiple sets of experimental flow channels;

[0008] The experimental flow channel includes: an outer tube and an inner tube arranged concentrically; a narrow slit is formed between the outer tube and the inner tube; the inner tube diameter is different for different experimental flow channels;

[0009] The outer pipe is provided with a cold water inlet at one end and a cold water outlet at the other end; the cold water inlet and cold water outlet are connected to the cold water circulation system;

[0010] The inner pipe has a hot water inlet at one end and a hot water outlet at the other end; the hot water inlet and hot water outlet are connected to the hot water circulation system.

[0011] Preferably, the cold water circulation system includes: a cold water tank, a cold water pump, a cold water inlet pipe, and a cold water outlet pipe;

[0012] The inlet of the cold water pump is connected to the cold water tank, the outlet of the cold water pump is connected to the cold water inlet pipe, and the cold water inlet pipe is detachably connected to the cold water inlet of each outer pipe.

[0013] The cold water outlet of each outer pipe is connected to the cold water outlet pipe.

[0014] Preferably, the hot water circulation system includes: a hot water tank, a hot water pump, a hot water inlet pipe, and a hot water outlet pipe;

[0015] The inlet of the hot water pump is connected to the hot water tank, and the outlet of the hot water pump is connected to the hot water inlet pipe. The hot water inlet pipe is detachably connected to the hot water inlet of each inner pipe.

[0016] The hot water outlet pipe is detachably connected to the hot water outlet of each inner pipe.

[0017] Preferably, a turbine flow meter, an inlet pressure transmitter, and an inlet temperature sensor are installed after the cold water pump in the cold water inlet pipe;

[0018] An outlet temperature sensor and an outlet pressure transmitter are installed on the cold water outlet pipe.

[0019] Preferably, the cold water inlet pipe is connected to the cold water inlet of the outer pipe via a detachable connector;

[0020] The hot water inlet pipe is connected to the hot water inlet of the inner pipe via a detachable connector.

[0021] Preferably, manual ball valves are provided at the cold water inlet and cold water outlet.

[0022] Preferably, the cold water outlet pipe is connected to the wastewater tank;

[0023] The cold water inlet pipe and cold water outlet pipe are made of explosion-proof PU pipe.

[0024] Preferably, the outer and inner tubes of the experimental flow channel are made of copper.

[0025] Preferably, the adjustable narrow slit flow channel module further includes: at least one set of control flow channels;

[0026] The control flow channel includes: an outer tube and an inner tube arranged concentrically;

[0027] The inner tube of the control flow channel has the same diameter as the inner tube of at least one set of experimental flow channels;

[0028] The outer and inner tubes of the control flow channel are made of different materials than those of the experimental flow channel.

[0029] Preferably, the experimental flow channel and the control flow channel are mounted on an angle steel bracket.

[0030] The narrow-slit annular flow channel experimental device provided by this utility model has the following advantages compared with the prior art:

[0031] 1. This utility model has strong multi-parameter and multi-condition experimental capabilities, including four sets of experimental flow channels with different gaps (inner and outer tubes are made of copper) and one set of control flow channels (inner and outer tubes are made of stainless steel). It can meet the comparative experimental needs of flow channels with different gaps and materials, and can study the fluid resistance and heat transfer characteristics under different conditions, providing rich experimental data for related research.

[0032] 2. This invention offers high data accuracy. The outer and inner tubes employ a concentric nested design, which avoids measurement errors in fluid flow and heat transfer characteristics caused by concentricity deviations. This solves the problem of unstable flow channel structures in traditional devices affecting experimental accuracy. The flow channel structure exhibits high stability, flexible operation, and excellent performance.

[0033] 3. This utility model has strong safety and convenience. The cold water inlet pipe and cold water outlet pipe are made of explosion-proof PU pipe. The explosion-proof characteristics improve the safety during the experiment, especially when dealing with high temperature or high pressure fluids, reducing the risk of leakage.

[0034] 4. The cold water inlet pipe is connected to the cold water inlet of the outer pipe through a detachable connector; the hot water inlet pipe is connected to the hot water inlet of the inner pipe through a detachable connector. The detachable design facilitates the cleaning, replacement and maintenance of the pipes, and is more flexible than the fixed connection of traditional devices.

[0035] 5. This utility model offers more flexible operation and superior performance. The manual ball valve features a compact structure, high stem transmission efficiency, and low torque required for manual operation, significantly improving operational efficiency. The manual ball valve has bidirectional sealing capability, eliminating the need to consider the medium flow direction during installation, thus facilitating pipeline design and installation. The ball's channel is essentially the same as the pipeline's inner diameter, allowing the medium to pass through in a straight line. Its extremely low flow resistance coefficient reduces energy loss during transport, improving the operational efficiency of the pipeline system. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the narrow-slit annular flow channel experimental device provided by this utility model;

[0037] Figure 2 This is a schematic diagram of concentrically nested outer and inner tubes;

[0038] Figure 3 This is a magnified view of the outer and inner pipes at the cold water inlet.

[0039] Reference numerals: 1. Cold water tank; 2. Hot water tank; 3. Hot water outlet pipe; 4. Hot water inlet pipe; 5. Cold water pump; 6. Hot water pump; 7. Turbine flow meter; 8. Inlet pressure transmitter; 9. Inlet temperature sensor; 10. Cold water inlet pipe; 11. Manual ball valve; 12. Outer pipe; 13. Inner pipe; 14. Cold water inlet; 15. Cold water outlet; 16. Outlet temperature sensor; 17. Outlet pressure transmitter; 18. Wastewater tank; 19. Angle steel bracket; 20. Control flow channel; 21. Experimental flow channel; 22. Cold water outlet pipe. Detailed Implementation

[0040] To make the technical problems solved by this utility model, the technical solutions adopted, and the technical effects achieved clearer, this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining this utility model and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this utility model are shown in the accompanying drawings, not all of them.

[0041] like Figure 1 As shown in the figure, the present invention provides a narrow slit annular flow channel experimental device, including: an adjustable narrow slit flow channel module, a cold water circulation system and a hot water circulation system.

[0042] The adjustable narrow slit flow channel module includes: multiple sets of experimental flow channels 21 and at least one set of control flow channels 20. The experimental flow channels 21 and control flow channels 20 are mounted on an angle steel bracket 19, which provides stable support for the experimental flow channels 21 and control flow channels 20.

[0043] like Figure 2-3As shown, the experimental flow channel 21 includes an outer tube 12 and an inner tube 13 arranged concentrically; the outer tube 12 and the inner tube 13 are ensured to be concentric during installation. The gap between the inner tube 12 and the outer tube 13 is welded, and the inner tube 13 is continuous. The concentric nesting of the outer tube 12 and the inner tube 13 makes the structure compact, significantly improves the heat exchange efficiency, avoids mixing or cross-contamination of the flowing medium, and reduces the risk of leakage.

[0044] An annular narrow slit is formed between the outer tube 12 and the inner tube 13; the diameter of the inner tube 13 is different for different experimental flow channels 21. Specifically, four sets of experimental flow channels 21 and one set of control flow channels 20 can be set up. The outer diameter of the outer tube 12 is 20 mm. The slit gaps of the four sets of experimental flow channels 21 are 0.5 mm, 1.0 mm, 1.5 mm, and 2.0 mm, respectively. The outer tube 12 and inner tube 13 of the four sets of experimental flow channels 21 are made of copper.

[0045] The outer pipe 12 is provided with a cold water inlet 14 at one end and a cold water outlet 15 at the other end; the cold water inlet 14 and the cold water outlet 15 are connected to the cold water circulation system; the cold water in the narrow slit enters from the cold water inlet 14 and flows out from the cold water outlet 15.

[0046] The inner pipe 13 has a hot water inlet at one end and a hot water outlet at the other end; the hot water inlet and hot water outlet are connected to the hot water circulation system. Hot water in the inner pipe 13 enters through the hot water inlet and flows out through the hot water outlet.

[0047] The cold water circulation system includes: a cold water tank 1, a cold water pump 5, a cold water inlet pipe 10, and a cold water outlet pipe 22. The inlet of the cold water pump 5 is connected to the cold water tank 1, and the outlet of the cold water pump 5 is connected to the cold water inlet pipe 10. The cold water inlet pipe 10 is detachably connected to the cold water inlet 14 of each outer pipe 12. The cold water outlet 15 of each outer pipe 12 is connected to the cold water outlet pipe 22. The cold water outlet pipe 22 is connected to a wastewater tank 18. Specifically, the cold water inlet pipe 10 is connected to the cold water inlet 14 of the outer pipe 12 via a detachable connector; the hot water inlet pipe 4 is connected to the hot water inlet of the inner pipe 13 via a detachable connector.

[0048] A turbine flow meter 7, an inlet pressure transmitter 8, and an inlet temperature sensor 9 are installed after the cold water pump 5 on the cold water inlet pipe 10. The turbine flow meter 7 measures the flow rate of the cold water. The inlet pressure transmitter 8 measures the inlet pressure of the cold water. The inlet temperature sensor 9 measures the inlet temperature of the cold water. An outlet temperature sensor 16 and an outlet pressure transmitter 17 are installed on the cold water outlet pipe 22. The outlet temperature sensor 16 measures the outlet temperature of the cold water. The outlet pressure transmitter 17 measures the outlet pressure of the cold water. The inlet temperature sensor 9 and the outlet temperature sensor 16 can be PT100 temperature sensors. The inlet pressure transmitter 8 and the outlet pressure transmitter 17 are PCM-300 pressure transmitters. The turbine flow meter 7 is an LWGY-15 turbine flow meter. The cold water inlet pipe 10 and the cold water outlet pipe 22 are made of explosion-proof PU tubing. Manual ball valves 11 with bidirectional sealing function are installed at the cold water inlet 14 and the cold water outlet 15.

[0049] The hot water circulation system includes: a hot water tank 2, a hot water pump 6, a hot water inlet pipe 4, and a hot water outlet pipe 3; the inlet of the hot water pump 6 is connected to the hot water tank 2, the outlet of the hot water pump 6 is connected to the hot water inlet pipe 4, the hot water inlet pipe 4 is detachably connected to the hot water inlet of each inner pipe 13; and the hot water outlet pipe 3 is detachably connected to the hot water outlet of each inner pipe 13.

[0050] Cold water and hot water flow in a counter-current convection pattern, forming counter-current heat exchange. Cold water is drawn from cold water tank 1 by cold water pump 5, driving it into cold water inlet 14. The cold water then enters the narrow gap between outer pipe 12 and inner pipe 13, flows out from cold water outlet 15 and cold water outlet pipe 22, and enters wastewater tank 18. Hot water is drawn from hot water tank 2 by hot water pump 6, driving it into hot water inlet. The hot water then enters inner pipe 13 and flows out from hot water outlet and hot water outlet pipe 3, returning to hot water tank 2.

[0051] Based on the above scheme, the adjustable narrow slit flow channel module further includes: at least one set of control flow channels 20; the control flow channel 20 also includes an outer tube 12 and an inner tube 13 arranged concentrically. The inner tube 13 of the control flow channel 20 has the same diameter as the inner tube 13 of at least one set of experimental flow channels 21; the outer tube 12 and inner tube 13 of the control flow channel 20 are made of different materials than the outer tube 12 and inner tube 13 of the experimental flow channel 21. Specifically, this embodiment sets up a set of control flow channels 20, and the narrow slit gap of the control flow channel 20 is 1.0 mm. The outer tube 12 and inner tube 13 of the control flow channel 20 are made of stainless steel pipe, which is different from the material of the outer tube 12 and inner tube 13 of the experimental flow channel 21 (copper pipe), and the same narrow slit gap with different materials serves as an experimental control.

[0052] In use, the narrow-slit annular flow channel experimental device of this utility model draws cold water from the cold water tank 1 by the cold water pump 5, passes through the turbine flow meter 7, the inlet pressure transmitter 8, and the inlet temperature sensor 9, and enters the narrow slit between the outer pipe 12 and the inner pipe 13 through the cold water inlet pipe 10 and the cold water inlet 14; hot water is drawn from the hot water tank 2 by the hot water pump 6 and flows directly into the inner pipe 13; the cold water and hot water adopt a counter-current convection form, which makes the temperature difference distribution more uniform, saves heat exchange area, and reduces equipment cost and space occupation; cold water flows out from the cold water outlet 15 and enters the cold water outlet pipe 22, passes through the outlet temperature sensor 16 and the outlet pressure transmitter 17 and flows into the wastewater tank 18; hot water flows out from the inner pipe 13 and flows back to the hot water tank 2.

[0053] Turbine flow meter 7 measures the flow rate Q of the cold water, inlet pressure transmitter 8 measures the inlet pressure p1 of the cold water, and inlet temperature sensor 9 measures the inlet temperature t1 of the cold water. Outlet temperature sensor 16 measures the outlet temperature t2 of the cold water. Outlet pressure transmitter 17 measures the outlet pressure p2 of the cold water. These measured parameters can be used to study fluid resistance and heat transfer characteristics under different conditions, providing rich experimental data for related research. The Reynolds number Re is obtained from the cold water flow rate Q; the drag coefficient λ is obtained from the inlet and outlet pressures p1 and p2; and the Nusselt number Nu is obtained from the inlet and outlet temperatures t1 and t2. The fluid resistance characteristics are studied using the Reynolds number Re and the drag coefficient λ; and the fluid heat transfer characteristics are studied using the Reynolds number Re and the Nusselt number Nu.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions for some or all of the technical features, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A narrow-slit annular flow channel experimental apparatus, characterized in that, include: Adjustable narrow slit flow channel module, cold water circulation system and hot water circulation system; The adjustable narrow slit flow channel module includes: multiple sets of experimental flow channels (21); The experimental flow channel (21) includes: an outer tube (12) and an inner tube (13) arranged concentrically; a narrow slit is formed between the outer tube (12) and the inner tube (13); the inner tube (13) of different experimental flow channels (21) has a different diameter; The outer pipe (12) is provided with a cold water inlet (14) at one end and a cold water outlet (15) at the other end; the cold water inlet (14) and the cold water outlet (15) are connected to the cold water circulation system; The inner tube (13) has a hot water inlet at one end and a hot water outlet at the other end; the hot water inlet and hot water outlet are connected to the hot water circulation system.

2. The narrow-slit annular flow channel experimental apparatus according to claim 1, characterized in that, The cold water circulation system includes: a cold water tank (1), a cold water pump (5), a cold water inlet pipe (10), and a cold water outlet pipe (22); The inlet of the cold water pump (5) is connected to the cold water tank (1), the outlet of the cold water pump (5) is connected to the cold water inlet pipe (10), and the cold water inlet pipe (10) is detachably connected to the cold water inlet (14) of each outer pipe (12). The cold water outlet (15) of each outer pipe (12) is connected to the cold water outlet pipe (22).

3. The narrow-slit annular flow channel experimental apparatus according to claim 2, characterized in that, The hot water circulation system includes: a hot water tank (2), a hot water pump (6), a hot water inlet pipe (4), and a hot water outlet pipe (3); The inlet of the hot water pump (6) is connected to the hot water tank (2), the outlet of the hot water pump (6) is connected to the hot water inlet pipe (4), and the hot water inlet pipe (4) is detachably connected to the hot water inlet of each inner pipe (13). The hot water outlet pipe (3) is detachably connected to the hot water outlet of each inner pipe (13).

4. The narrow-slit annular flow channel experimental apparatus according to claim 2, characterized in that, The cold water inlet pipe (10) is equipped with a turbine flow meter (7), an inlet pressure transmitter (8), and an inlet temperature sensor (9) after the cold water pump (5); An outlet temperature sensor (16) and an outlet pressure transmitter (17) are installed on the cold water outlet pipe (22).

5. The narrow-slit annular flow channel experimental apparatus according to claim 3, characterized in that, The cold water inlet pipe (10) is connected to the cold water inlet (14) of the outer pipe (12) by a detachable connector; The hot water inlet pipe (4) is connected to the hot water inlet of the inner pipe (13) by a detachable connector.

6. The narrow-slit annular flow channel experimental apparatus according to claim 2, characterized in that, Manual ball valves (11) are provided at the cold water inlet (14) and cold water outlet (15).

7. The narrow-slit annular flow channel experimental apparatus according to claim 2, characterized in that, The cold water outlet pipe (22) is connected to the wastewater tank (18); The cold water inlet pipe (10) and cold water outlet pipe (22) are made of explosion-proof PU pipe.

8. The experimental apparatus for a narrow-slit annular flow channel according to claim 1, characterized in that, The outer tube (12) and inner tube (13) of the experimental flow channel (21) are made of copper.

9. The experimental apparatus for a narrow-slit annular flow channel according to claim 1, characterized in that, The adjustable narrow slit flow channel module further includes: at least one set of control flow channels (20); The control flow channel (20) includes: an outer tube (12) and an inner tube (13) arranged in concentric nesting arrangements; The inner tube (13) of the control flow channel (20) has the same diameter as the inner tube (13) of at least one set of experimental flow channels (21); The outer tube (12) and inner tube (13) of the control flow channel (20) are made of different materials than the outer tube (12) and inner tube (13) of the experimental flow channel (21).

10. The narrow-slit annular flow channel experimental apparatus according to claim 9, characterized in that, The experimental flow channel (21) and the control flow channel (20) are set on the angle steel bracket (19).

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