A single-tube refrigeration unit and heat exchanger based on M cycle

Abstract

The present invention first proposes a single-tube refrigeration unit based on the M cycle, comprising an insulated outer tube, a coaxial heat pipe disposed within the insulated outer tube, the heat pipe being open at both ends, a gap being provided between the outer wall of the heat pipe and the inner wall of the insulated outer tube, a dry channel being formed within the heat pipe, and a wet channel being formed between the gap between the heat pipe and the insulated outer tube. A diversion zone is provided within one end of the insulated outer tube, and a water film is provided on the outer wall of the heat pipe. The dry and wet channels are tubular in structure. At the same dry-wet ratio, the airflow velocity in the wet channel is greater, evaporation is more intense, greater heat absorption is achieved, and the temperature reduction is greater. The counterflow zone is expanded into a cavity directly enclosed by the outer shell, which minimizes disturbance to the counterflow airflow. The tubular refrigeration channel can increase the heat exchange area per unit volume to a certain extent, thereby achieving a greater cooling capacity per unit volume. The circular pipe cross-section design allows dry air to fully exchange heat through the heat-conducting material from all directions, resulting in a significant temperature reduction. The present invention also proposes a heat exchanger.

Description

Technical Field

[0001] The present invention relates to the technical field of evaporative refrigeration equipment, and in particular to a single-tube refrigeration unit and a heat exchanger based on an M cycle. Background Art

[0002] The compressor air conditioners currently in the mainstream refrigeration market consume a lot of energy, significantly increasing societal energy losses. Furthermore, their refrigerants are fluorinated, which can severely damage the environment over time. Emerging evaporative cooling air conditioners, such as direct evaporative water-cooled air conditioners, significantly reduce energy consumption compared to compressor air conditioners, but generally suffer from limited cooling ranges and low cooling efficiency, making them unable to meet cooling needs. Therefore, it is crucial to innovate evaporative cooling technology and develop new structures that combine low energy consumption with excellent cooling performance and high cooling efficiency. Summary of the Invention

[0003] In view of this, an object of the present invention is to provide a single-tube refrigeration unit and a heat exchanger based on an M cycle, which have excellent refrigeration effect and high refrigeration efficiency.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] The present invention first proposes a single-tube refrigeration unit based on the M cycle, including an insulated outer tube with openings at both ends, a coaxial heat-conducting tube is arranged inside the insulated outer tube, the heat-conducting tube is open at both ends, a gap is provided between the outer wall of the heat-conducting tube and the inner wall of the insulated outer tube, a dry channel is formed inside the heat-conducting tube, and a wet channel is formed by the gap between the heat-conducting tube and the insulated outer tube, a diversion area is provided inside one end of the insulated outer tube, and a water film is provided on the outer wall of the heat-conducting tube.

[0006] Furthermore, the heat-insulating outer tube is provided with a clearance notch for making way for the water film, and the water film extends to the outside of the heat-insulating outer tube through the clearance notch.

[0007] Furthermore, it also includes a fixing mechanism for fixing the heat-conducting pipe, and the fixing mechanism includes a radial fixing mechanism for keeping the heat-conducting pipe and the heat-insulating outer pipe coaxial and an axial fixing mechanism for preventing the heat-conducting pipe from moving along its axial direction.

[0008] Furthermore, the radial fixing mechanism includes a first fixing block evenly distributed annularly between the outer wall of the heat conducting pipe and the inner wall of the insulating outer pipe, one end of the first fixing block is connected to the outer wall of the heat conducting pipe and the other end is in contact with the inner wall of the insulating outer pipe.

[0009] Furthermore, the axial fixing mechanism includes a fixed baffle ring, and a second fixed block is evenly distributed in an annular shape between the inner wall of the fixed baffle ring and the outer wall of the heat conduction tube. The fixed baffle ring is located at one end of the insulation outer tube and has a contact surface that contacts the end face of the insulation outer tube.

[0010] Furthermore, the heat-insulated outer tube is provided with an end cap at one end where the diversion area is located, and the end cap is provided with an air flow outlet.

[0011] Furthermore, one end of the heat conducting pipe facing away from the end head extends to the outside of the heat insulating outer pipe.

[0012] The present invention also proposes a heat exchanger, comprising a shell with openings at both ends, a refrigeration module being provided in the shell, the refrigeration module comprising a plurality of single-tube refrigeration units as described in any one of the above items arranged in an array, a dry channel inlet and a dry channel outlet being provided at both ends of the shell, a wet channel outlet being provided on the shell, the dry channel inlet and the dry channel outlet being connected to the dry channel, the wet channel outlet being connected to the wet channel, and the dry channel inlet and the wet channel outlet being connected to fans respectively.

[0013] Furthermore, a first partition and a second partition are provided in the shell, the first partition is located on the outside of the second partition, the outside of the first partition and the end of the shell form the dry channel entrance, and the area between the first partition and the second partition forms the wet channel exit. An opening is provided on the shell, and the opening is connected to the wet channel exit. The dry channel exit is formed at the end of the shell away from the first partition and the second partition.

[0014] Furthermore, it also includes a water tank, and one end of the water film extends into the water tank.

[0015] The beneficial effects of the present invention are:

[0016] The single-tube refrigeration unit based on the M cycle of the present invention has a tubular structure for the dry and wet channels. When the dry-wet ratio is the same, the airflow velocity in the wet channel is greater, the evaporation is more intense, more heat is absorbed, and the temperature reduction is greater. The counterflow area is expanded to become a cavity directly enclosed by the shell, which has less disturbance to the counterflow airflow. The tubular refrigeration channel can also increase the heat exchange area per unit volume to a certain extent, thereby achieving a greater unit volume cooling capacity. The circular pipe cross-section design allows dry air to fully exchange heat through the heat conductive material from all directions, resulting in a large temperature reduction.

[0017] The heat exchanger of the present invention has the effects of large temperature reduction range and high refrigeration efficiency by arranging a refrigeration module with multiple single-tube refrigeration units in a shell.

[0018] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the purpose, technical solutions and beneficial effects of the present invention more clear, the present invention provides the following drawings for illustration:

[0020] Figure 1 It is a structural schematic diagram of an embodiment of a single-tube refrigeration unit of the present invention;

[0021] Figure 2 Schematic diagram of the internal structure of a single-tube refrigeration unit embodiment of the present invention;

[0022] Figure 3 is a cross-sectional view of an embodiment of a single-tube refrigeration unit of the present invention;

[0023] Figure 4 Schematic diagram of heat pipe;

[0024] Figure 5 Schematic diagram of the heat-insulated outer tube 1;

[0025] Figure 6 Schematic diagram of the structure of a heat exchanger embodiment;

[0026] Figure 7 Schematic diagram of the internal structure of a heat exchanger embodiment;

[0027] Figure 8 This is the schematic diagram of the M cycle;

[0028] Figure 9 Schematic diagram of temperature change in the dry channel of a conventional flat-plate countercurrent dew-point indirect evaporation heat exchange structure;

[0029] Figure 10 This is a schematic diagram of temperature changes in a single-tube refrigeration unit of the present invention;

[0030] Figure 11 This is the simulated temperature drop of a conventional flat-plate countercurrent dew-point indirect evaporation heat exchange structure;

[0031] Figure 12 This is the simulated temperature drop for the single-tube refrigeration unit of the present invention.

[0032] Description of reference numerals:

[0033] 1-insulated outer tube; 2-heat conducting tube; 3-dry channel; 4-wet channel; 5-diversion area; 6-water film; 7-gap; 8-first fixing block; 9-fixing baffle; 10-second fixing block; 11-end; 12-air flow outlet; 13-housing; 14-dry channel inlet; 15-dry channel outlet; 16-first partition; 17-second partition; 18-opening; 19-water tank; 20-wet channel outlet. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0035] Example 1 - Single-tube refrigeration unit based on M cycle

[0036] like Figure 1-Figure 5 As shown in , this embodiment discloses a single-tube refrigeration unit based on the M cycle, comprising an insulated outer tube 1 with both ends open. A coaxial heat pipe 2 is disposed within the insulated outer tube 1. In this embodiment, the heat pipe 2 is made of an aluminum tube and is open at both ends. A gap is provided between the outer wall of the heat pipe 2 and the inner wall of the insulated outer tube 1, forming a dry channel 3 within the heat pipe 2 and a wet channel 4 between the heat pipe 2 and the insulated outer tube 1. A diversion region 5 is provided within one end of the insulated outer tube 1, and a water film 6 is provided on the outer wall of the heat pipe 2. In this embodiment, one end of the heat pipe 2 extends outside the insulated outer tube 1. The extended end serves as the dry channel inlet, and the other end serves as the dry channel outlet. The gap between the extended end of the heat pipe 2 and the insulated outer tube 1 serves as the wet channel outlet.

[0037] As shown in the figure, the insulating outer tube 1 of this embodiment is provided with a clearance notch 7 for accommodating the water film 6. The water film 6 extends outside the insulating outer tube 1 through the clearance notch 7. Specifically, in this embodiment, the water film 6 is formed by natural fibers absorbing water and adhering to the outer wall of the heat conducting tube 2. The water film 6 is connected to a water source through the clearance notch 7, facilitating the continuous replenishment of moisture in the water film 6.

[0038] like Figure 2 and Figure 4 As shown in , the single-tube refrigeration unit of this embodiment also includes a fixing mechanism for fixing the heat-conducting pipe 2, which includes a radial fixing mechanism for keeping the heat-conducting pipe 2 coaxial with the insulating outer pipe 1 and an axial fixing mechanism for preventing the heat-conducting pipe 2 from moving along its axial direction.

[0039] Specifically, the radial fixing mechanism includes a first fixing block 8 evenly distributed in an annular manner between the outer wall of the heat-conducting tube 2 and the inner wall of the heat-insulating outer tube 1. One end of the first fixing block 8 is connected to the outer wall of the heat-conducting tube 2, and the other end is in contact with the inner wall of the heat-insulating outer tube 1. In this embodiment, three first fixing blocks 8 are evenly distributed in an annular manner between the outer wall of the heat-conducting tube 2 and the inner wall of the heat-insulating outer tube 1. The axial fixing mechanism includes a fixed retaining ring 9. Second fixing blocks 10 are evenly distributed in an annular manner between the inner wall of the fixed retaining ring 9 and the outer wall of the heat-conducting tube 2. The fixed retaining ring 9 is located at one end of the heat-insulating outer tube 1 and has a contact surface that contacts the end face of the heat-insulating outer tube 1. In this embodiment, the inner diameter and outer diameter of the fixed retaining ring 9 are consistent with the inner diameter and outer diameter of the heat-insulating outer tube 1, and three second fixing blocks 10 are evenly distributed in an annular manner between the inner wall of the fixed retaining ring 9 and the outer wall of the heat-conducting tube 2.

[0040] like Figure 1 As shown in FIG, the end of the heat-insulated outer tube 1 located at the diversion area 5 is provided with an end cap 11, and the end cap 11 is provided with an air flow outlet 12. This facilitates forming the diversion area 5 at the end where the end cap 11 is located.

[0041] Figure 8 The M-cycle schematic diagram illustrates the operation process as follows: Hot air (dry air) with a low water vapor content in the environment is blown into the dry channel by a fan. It is separated at the diversion zone at the end of the dry channel, with a portion flowing back into the wet channel. The wet channel and dry channel are separated by a thermally conductive material, whose surface is covered by a water film. As the dry air flowing back into the wet channel passes over the water film, the difference in water vapor concentration causes water on the surface of the water film to diffuse (evaporate) into the dry air. The energy required for this evaporation process is the latent heat of water, which comes from the internal energy of water, thus lowering the temperature of the water film. To maintain energy stability in the wet channel and replenish the latent heat lost due to evaporation, a portion of the energy comes from heat transfer from the thermally conductive material. This heat transfer from the dry channel to the wet channel via the thermally conductive material lowers the temperature of the dry channel. As the dry air backflows through the wet channel, promoting water evaporation, its water vapor content increases, gradually becoming saturated with wet air. Simultaneously, the evaporation process weakens, and the temperature in the wet channel approaches that of the ambient dry air. After the counterflow process in the wet channel is completed, the wet air (working air) is blown out from the wet channel outlet by the fan. The evaporation process in the wet channel and the cooling process in the dry channel proceed synchronously, causing the air flow along the dry channel to cool down and become cold air. After reaching a steady state, the cold air (product air) that has not flowed back into the wet channel flows out from the dry channel outlet.

[0042] When the single-tube refrigeration unit of this embodiment is cooling, a fan is used at the entrance of the dry channel 3 to blow hot air (dry air) with a low moisture content into the dry channel 3, and the airflow flows along the dry channel 3; at the same time, a fan is used at the outlet of the wet channel 4 to extract the working airflow in the wet channel 3, and then a diversion will occur when the airflow flows to the diversion area 5. The working airflow that flows countercurrently into the wet channel 4 promotes the evaporation of water on the surface of the water film 6 to absorb heat during flow, and uses the heat pipe 2 as a heat conduction medium to indirectly consume the heat transferred from the hot air in the dry channel 3, thereby reducing the temperature in the dry channel 3. When the working airflow flows in the wet channel 4, the moisture content gradually increases to saturation, and after becoming saturated wet air, it is extracted from the wet channel outlet at the fixed baffle ring 9. After the refrigeration reaches a steady state, the temperature along the dry channel 3 decreases, and the remaining cold air diverted becomes the product airflow and is discharged from the product airflow outlet at the port.

[0043] like Figures 9-12 As shown in , in simulation tests conducted under the same air inlet conditions, the same channel length, and the same channel height, the single-tube refrigeration unit of this embodiment has a greater advantage in cooling amplitude compared to the commonly used flat-plate counterflow structure.

[0044] Example 2 - Heat Exchanger

[0045] like Figure 6 and Figure 7 As shown in , the present invention also discloses a heat exchanger, including a shell 13 with openings at both ends, a refrigeration module is provided in the shell 13, and the refrigeration module includes a plurality of single-tube refrigeration units as described in Example 1 arranged in an array, a dry channel inlet 14 and a dry channel outlet 15 are respectively provided at both ends of the shell 13, and a wet channel outlet 20 is provided on the shell 13, the dry channel inlet 14 and the dry channel outlet 15 are both connected to the dry channel 3, the wet channel outlet 20 is connected to the wet channel 4, and the dry channel inlet 14 and the wet channel outlet 20 are respectively connected to fans. Specifically, a first partition 16 and a second partition 17 are spaced apart within the housing 13. The first partition 16 is located outside the second partition 17. The outer side of the first partition 16 and the end of the housing 13 form a dry channel inlet 14. The area between the first partition 16 and the second partition 17 forms a wet channel outlet 20. An opening 18 is provided on the housing 13, which is connected to the wet channel outlet 20. The fan can communicate with the wet channel outlet 20 through the opening 18. A dry channel outlet 15 is formed within the housing 13 at the end opposite to the first partition 16 and the second partition 17. In this embodiment, the first partition 16 and the second partition 17 are provided with a clearance hole for the passage of the heat pipe 2. The aperture of the clearance hole is substantially the same as the outer diameter of the heat pipe 2. The heat pipe 2 passes through the clearance hole on the first partition 16 and the second partition 17 to reach the dry channel inlet 14. The first partition 16 and the second partition 17 can also serve to secure the single-tube refrigeration unit.

[0046] like Figure 7 As shown in , the heat exchanger of this embodiment further includes a water tank 19 , one end of the water film 6 extends into the water tank 19 , and a water filling hole is provided on the shell 13 at the position where the water tank 19 is located, so as to facilitate adding water to the inside of the water tank 19 .

[0047] The above embodiments are merely preferred embodiments for the purpose of fully illustrating the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are within the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

Claims

1. A single-tube refrigeration unit based on an M cycle, characterized in that: The invention comprises a heat-insulating outer tube (1) with openings (18) at both ends, a heat-conducting tube (2) coaxial with the heat-insulating outer tube (1) is provided inside the heat-insulating outer tube (1), the heat-conducting tube (2) has openings (18) at both ends, a gap is provided between the outer wall of the heat-conducting tube (2) and the inner wall of the heat-insulating outer tube (1), a dry channel (3) is formed inside the heat-conducting tube (2), a wet channel (4) is formed by the gap between the heat-conducting tube (2) and the heat-insulating outer tube (1), a diversion area (5) is provided inside one end of the heat-insulating outer tube (1), and a water film (6) is provided on the outer wall of the heat-conducting tube (2); The heat-insulating outer tube (1) is provided with a clearance notch (7) for making way for the water film (6), and the water film (6) extends to the outside of the heat-insulating outer tube (1) through the clearance notch (7); the heat-insulating outer tube (1) is provided with an end cap (11) at one end where the diversion area (5) is located, and an air flow outlet (12) is provided on the end cap (11).

2. The single-tube refrigeration unit based on the M cycle according to claim 1, characterized in that: It also includes a fixing mechanism for fixing the heat-conducting pipe (2), the fixing mechanism including a radial fixing mechanism for keeping the heat-conducting pipe (2) coaxial with the heat-insulating outer pipe (1) and an axial fixing mechanism for preventing the heat-conducting pipe (2) from moving along its axial direction.

3. The single-tube refrigeration unit based on the M cycle according to claim 2, characterized in that: The radial fixing mechanism comprises a first fixing block (8) uniformly arranged in an annular manner between the outer wall of the heat-conducting tube (2) and the inner wall of the heat-insulating outer tube (1), one end of the first fixing block (8) being connected to the outer wall of the heat-conducting tube (2) and the other end being in contact with the inner wall of the heat-insulating outer tube (1).

4. The single-tube refrigeration unit based on the M cycle according to claim 2, characterized in that: The axial fixing mechanism comprises a fixing retaining ring (9), a second fixing block (10) being evenly distributed in an annular pattern between the inner wall of the fixing retaining ring (9) and the outer wall of the heat conducting tube (2), the fixing retaining ring (9) being located at one end of the heat insulating outer tube (1) and having a contact surface in contact with the end face of the heat insulating outer tube (1).

5. The single-tube refrigeration unit based on the M cycle according to claim 1, characterized in that: One end of the heat conducting pipe (2) facing away from the end head (11) extends to the outside of the heat insulating outer pipe (1).

6. A heat exchanger, characterized in that : A shell (13) having openings (18) at both ends, a refrigeration module being arranged in the shell (13), the refrigeration module comprising a plurality of single-tube refrigeration units according to any one of claims 1 to 5 arranged in an array, a dry channel inlet (14) and a dry channel outlet (15) being respectively provided at both ends of the shell (13), a wet channel outlet (20) being provided on the shell (13), the dry channel inlet (14) and the dry channel outlet (15) both being in communication with the dry channel (3), the wet channel outlet (20) being in communication with the wet channel (4), and the dry channel inlet (14) and the wet channel outlet (20) being respectively connected to fans.

7. The heat exchanger according to claim 6, characterized in that: A first partition (16) and a second partition (17) are provided in the shell (13) at intervals. The first partition (16) is located outside the second partition (17). The outside of the first partition (16) and the end of the shell (13) form the dry channel inlet (14). The area between the first partition (16) and the second partition (17) forms the wet channel outlet (20). An opening (18) is provided on the shell (13). The opening (18) is connected to the wet channel outlet (20). The dry channel outlet (15) is formed at the end of the shell (13) away from the first partition (16) and the second partition (17).

8. The heat exchanger according to claim 6, characterized in that: It also includes a water tank (19), and one end of the water film (6) extends into the water tank (19).

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