A jet cooling heat exchanger

Abstract

The present invention discloses a jet cooling heat exchanger, which includes a shell and a plurality of heat exchange tubes. The heat exchange tubes are arranged in an array structure to form a heat exchange tube bundle for circulating pressurized cooling medium. The heat exchange tubes include an upstream tapered tube section, an intermediate heat exchange tube section, and a downstream diverging tube section. Metal fins are arranged on the outer wall of the intermediate heat exchange tube section to enhance heat exchange. The intermediate heat exchange tube section is a constant diameter heat exchange tube section or a diverging heat exchange tube section. For weakly compressible and highly compressible working media, respectively, the heat exchange tubes can be connected end to end using elbows to form a series arrangement, arranged in parallel to form multiple flow channels, or arranged in parallel to form multiple flow channels using several layers of serpentine pipes. The shell is used to fix the heat exchange tube bundle and form a cooling space. The cooled fluid passes across the heat exchange tube bundle in the shell to exchange heat. The present invention uses pressurized fluid to achieve refrigeration and can be used to recover industrial excess pressure.

Description

Technical Field

[0001] The present invention belongs to the technical field of jet cooling heat exchange devices, and in particular relates to a jet cooling heat exchanger. Background Art

[0002] Refrigeration / cooling is a common energy-consuming process in daily life and industrial processes, with great energy-saving demand and potential. The development of efficient refrigeration heat exchangers is of great value and significance in reducing cooling and heat exchange energy consumption and improving the environment.

[0003] In existing refrigeration systems, throttling valves or capillary tubes are typically used to throttle and cool high-pressure fluids before they enter conventional heat exchangers (shell-and-tube, plate-and-tube, and tube-and-tube types) for cooling. However, this throttling process results in significant energy loss, resulting in low refrigeration efficiency. Furthermore, the temperature of the low-temperature fluid after throttling is nonlinearly related to the throttling device and the cooled fluid. Consequently, the cooling temperature requires gradual feedback adjustment, a process that is complex and time-consuming. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a jet cooling heat exchanger to solve the technical problems in the existing refrigeration system that the throttling process causes great loss of effective energy and the adjustment process is relatively complicated.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention discloses a jet cooling heat exchanger, comprising a shell and a plurality of heat exchange tubes;

[0007] A plurality of heat exchange tubes are arranged in an array to form a heat exchange tube bundle, and each heat exchange tube includes an upstream convergent tube section, an intermediate heat exchange tube section, and a downstream divergent tube section;

[0008] The heat exchange tube bundle is arranged across the shell, and the middle heat exchange tube sections of all heat exchange tubes are arranged inside the shell, and the upstream convergent tube section and the downstream divergent tube section are arranged outside the shell;

[0009] The working medium inlet and outlet of the heat exchange tube bundle are respectively connected to the cooling working medium pipeline;

[0010] The working medium inlet end and the working medium outlet end of the shell are respectively connected to the cooling fluid pipeline.

[0011] Preferably, the heat exchange tube bundle is configured to form a serpentine pipeline by connecting a plurality of heat exchange tubes end to end in series using an elbow.

[0012] Preferably, the heat exchange tube bundle is composed of several heat exchange tubes arranged in parallel to form multiple flow channels, and a fluid distributor is respectively provided between the inlet end of the heat exchange tube bundle and the cooling medium connection flange and between the outlet end of the heat exchange tube bundle and the cooling medium connection flange.

[0013] Preferably, the heat exchange tube bundle is composed of several layers of serpentine pipes arranged in parallel to form multiple flow channels, and each layer of serpentine pipes is composed of several heat exchange tubes connected end to end by elbows; and a fluid distributor is respectively provided between the inlet end of the heat exchange tube bundle and the cooling medium connection flange and between the outlet end of the heat exchange tube bundle and the cooling medium connection flange.

[0014] Preferably, the outer wall of the intermediate heat exchange tube section is provided with metal fins.

[0015] Further preferably, the metal fins are rectangular metal fins or wavy metal fins.

[0016] Further preferably, the metal fins are connected and fixed to the heat exchange tubes by welding or tube expansion.

[0017] Preferably, the intermediate heat exchange pipe section is a constant diameter heat exchange pipe section or a gradually expanding heat exchange pipe section.

[0018] Preferably, the working fluid inlet and outlet of the heat exchange tube bundle are connected to the cooling working fluid pipeline through a cooling working fluid connection flange respectively; the working fluid inlet and outlet of the shell are connected to the cooled fluid pipeline through a cooled fluid connection flange respectively.

[0019] Preferably, the heat exchange tube is fixed to the shell by welding.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The advantages of the jet cooling heat exchanger proposed in the present invention are: first, the heat exchange tube bundle is combined in an array structure, which is used for the circulation of pressurized cooling working medium; second, the heat exchange tube crosses the shell, and the shell is used to fix the heat exchange tube bundle and form a cooling heat exchange space inside the shell. The cooled fluid flows in the shell and exchanges heat with the heat exchange tube bundle; third, since the heat exchange tube is divided into three sections, and the middle heat exchange tube section is arranged inside the shell, and the other two parts are arranged outside the shell, the pressurized cooling working medium flows in from the upstream convergent tube section, the speed increases, the pressure decreases, and the temperature decreases. After the obtained low-temperature fluid enters the middle heat exchange tube section, it exchanges heat with the cooled fluid in the shell. After absorbing heat, the speed of the low-temperature fluid is increased, and part of the absorbed heat can be converted into pressure energy, realizing low-temperature heat utilization, reducing the pressure drop of the heat exchanger, and increasing the internal energy of the low-temperature fluid, which leads to an increase in the working medium flow rate. After the obtained high-speed fluid flows into the divergent tube section, the pressure is increased, the temperature is increased, and the speed is reduced, thereby obtaining a high-temperature pressurized fluid. In summary, the jet cooling heat exchanger proposed in the present invention can reduce the throttling loss in existing refrigeration technology, improve refrigeration efficiency, and the cooling temperature is easy to control, with high heat flux density, to achieve efficient refrigeration of pressurized fluid. In addition, the present invention is based on the expansion and cooling principle of the nozzle. The proposed jet cooling heat exchanger increases the speed, reduces the pressure, and reduces the temperature of the pressurized working fluid through a tapered pipeline to generate cooling capacity. At this time, the low-temperature temperature generated by the working fluid depends only on the state of the high-pressure fluid. It is only necessary to adjust the pressure and temperature of the pressurized fluid in the external system to obtain the specified low-temperature temperature, and the adjustment process is simple. After the high-speed working fluid exchanges heat, it is pressurized through a gradually expanding pipeline, which reduces the throttling loss compared to the conventional throttling to generate low temperatures, thereby achieving energy saving.

[0022] Furthermore, the heat exchange tube bundle is connected end to end by an elbow to form a serpentine pipe in series, thereby extending the length of the heat exchange tube and increasing the heat exchange area. The heat exchanger can be connected in order according to the heat exchange tube bundle array structure to ensure a compact structure.

[0023] Furthermore, the heat exchange tube bundle is composed of multiple parallel heat exchange tubes arranged into multiple flow channels, resulting in a large flow rate of working fluid, a large amount of heat exchange, and a high heat flux density within a small heat exchange area. A fluid distributor is installed between the inlet end of the heat exchange tube bundle and the cooling medium connection flange, and between the outlet end of the heat exchange tube bundle and the cooling medium connection flange to ensure that the working fluid is evenly distributed throughout the flow channels.

[0024] Furthermore, the heat exchange tube bundle is composed of several layers of serpentine pipes arranged in parallel to form multiple flow channels. Each layer of serpentine pipes is composed of several heat exchange tubes connected end to end by elbows. A fluid distributor is respectively provided between the inlet end of the heat exchange tube bundle and the cooling medium connection flange, and between the outlet end of the heat exchange tube bundle and the cooling medium connection flange, thereby obtaining a large heat exchange area, reducing pipeline losses, and reducing the size of the heat exchanger.

[0025] Furthermore, metal fins are provided on the outer wall of the middle heat exchange tube section to enhance heat exchange. The metal fins are rectangular metal fins or wavy metal fins, and the spacing between the metal fins can be adjusted according to specific requirements such as heat exchange power. The metal fins are connected and fixed to the heat exchange tube by welding or expansion tube.

[0026] Furthermore, the middle heat exchange tube section is a constant diameter heat exchange tube section for the working medium with weak compressibility; the middle heat exchange tube section of the heat exchange tube is a gradually expanding heat exchange tube section for the working medium with strong compressibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the three-dimensional structure of a single-channel series jet cooling heat exchanger disclosed in Example 1 of the present invention;

[0028] Figure 2 This is a three-dimensional schematic diagram of a multi-channel parallel jet cooling heat exchanger of a jet cooling heat exchanger disclosed in Example 2 of the present invention;

[0029] Figure 3 This is a three-dimensional schematic diagram of a double-channel series-parallel jet cooling heat exchanger disclosed in Example 3 of the present invention;

[0030] Figure 4 This is a cross-sectional schematic diagram of the present invention in which the intermediate heat exchange tube section is a heat exchange tube section of equal diameter;

[0031] Figure 5 It is a cross-sectional schematic diagram of the intermediate heat exchange tube section of the present invention being a gradually expanding heat exchange tube section;

[0032] Figure 6 This is a schematic diagram of the rectangular metal fin heat exchange tube bundle structure of the present invention;

[0033] Figure 7 This is a schematic diagram of the structure of the corrugated metal fin heat exchange tube bundle of the present invention.

[0034] Among them: 1-cooled fluid connection flange; 2-shell; 3-cooling medium connection flange; 4-heat exchange tube; 5-elbow; 6-fluid distributor; 7-rectangular metal fin; 8-wavy metal fin; 9-upstream convergent pipe section; 10-downstream divergent pipe section; 11-intermediate heat exchange pipe section. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0036] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0037] The present invention is described in further detail below with reference to the accompanying drawings:

[0038] Example 1

[0039] See also Figure 1 This is a schematic diagram of the three-dimensional structure of a single-channel series jet cooling heat exchanger disclosed in the present invention. The heat exchanger comprises a cooled fluid connection flange 1, a shell 2, a cooling medium connection flange 3, a heat exchange tube bundle consisting of a plurality of heat exchange tubes 4, and an elbow 5. The heat exchange tubes 4 are arranged in an array structure for the circulation of pressurized cooling medium. Each heat exchange tube 4 comprises an upstream tapered tube section 9, an intermediate heat exchange tube section 11, and a downstream diverging tube section 10. The elbow 5 connects the plurality of heat exchange tubes 4 end to end, arranging them in series into a serpentine pipeline. The inlet and outlet ends of the heat exchange tube bundle are respectively connected to the cooling medium pipeline via a cooling medium connection flange 3. The heat exchange tubes 4 pass vertically through the shell 2, with the intermediate heat exchange tube section 11 disposed within the shell 2 to form a cooling heat exchange space. The upstream tapered tube section 9, the downstream diverging tube section 10, and the elbow 5 are disposed outside the shell 2. The inlet and outlet ends of the shell 2 are respectively connected to the cooled fluid pipeline via a cooled fluid connection flange 1. Figure 1 The flow pattern of the cooled fluid and the cooling medium in the direction indicated by the middle arrow is countercurrent as a whole, which enhances heat exchange.

[0040] Preferably, the heat exchange tubes 4 are arranged in series as a single flow channel to form a serpentine pipe, and several heat exchange tubes 4 are connected end to end using elbows 5 to form a serpentine pipe by being arranged in series, that is, a 180° elbow 5 is used to connect the outlet of the upstream gradually expanding pipe section 9 with the inlet of the downstream gradually contracting pipe section 10 to form a series arrangement, and so on. The length of the heat exchange tube is extended, the heat exchange area is increased, and the heat exchange tube bundle array structure is connected in sequence to ensure that the heat exchanger structure is compact.

[0041] Preferably, the middle heat exchange pipe section 11 of the jet cooling heat exchanger disclosed in this embodiment 1 can be a constant diameter heat exchange pipe section or a gradually expanding heat exchange pipe section; see Figure 4 The cross-sectional view of the intermediate heat exchange pipe section 11 of the present invention is a heat exchange pipe section of equal diameter, and the equal diameter heat exchange pipe section is provided for the working medium with weak compressibility; Figure 5 This is a cross-sectional schematic diagram of the intermediate heat exchange pipe section 11 of the present invention, which is a gradually expanding heat exchange pipe section. The gradually expanding heat exchange pipe section is provided for working fluids with strong compressibility.

[0042] Preferably, the outer walls of the upstream tapered section 9, the intermediate heat exchange section 11, and the downstream diverging section 10 of the heat exchange tube 4 are all of a constant diameter structure, facilitating processing and installation. The heat exchange tube 4 is secured to the shell 2 by welding. During operation, the pressurized cooling fluid flows in through the upstream tapered section 9, where its velocity increases, its pressure decreases, and its temperature decreases. The resulting low-temperature fluid enters the intermediate heat exchange section 11, where it exchanges heat with the cooled fluid within the shell 2, increasing its internal energy and thereby increasing the fluid flow rate. The resulting high-speed fluid flows into the downstream diverging section 10, where it is pressurized, heated, and decelerated, resulting in a high-temperature pressurized fluid.

[0043] Preferably, the outer wall of the intermediate heat exchange tube section 11 of this embodiment 1 is evenly arranged with metal fins to enhance heat exchange. The metal fins are fixed to the heat exchange tube 4 by welding and arranged inside the shell 2. The metal fins can be rectangular metal fins 7 or wavy metal fins 8; see Figure 6 Schematic diagram of the heat exchange tube bundle structure coupled with rectangular metal fins 7; see Figure 7 Schematic diagram of the heat exchange tube bundle structure coupled with the corrugated metal fins 8.

[0044] Example 2

[0045] See also Figure 2The figure is a schematic perspective view of the multi-channel parallel jet cooling heat exchanger disclosed in Example 2. Unlike Example 1, the heat exchange tube bundle of the jet cooling heat exchanger disclosed in Example 2 comprises multiple heat exchange tubes 4 arranged in parallel to form multiple channels, and a fluid distributor 6 is provided between the inlet of the heat exchange tube bundle and the cooling medium connection flange 3, and between the outlet of the heat exchange tube bundle and the cooling medium connection flange 3. The cooling medium is evenly distributed to each heat exchange tube 4 through the fluid distributor 6 and exchanges heat with the cooled fluid within the shell 2. After absorbing heat, the cooling medium enters the fluid distributor 6 through the downstream diverging section 10 of the heat exchange tube 4, where it is mixed and flows out of the heat exchanger.

[0046] Example 3

[0047] See also Figure 3 The figure is a three-dimensional schematic diagram of a dual-channel series-parallel jet cooling heat exchanger of the jet cooling heat exchanger disclosed in this embodiment 3. Unlike embodiment 1, the heat exchange tube bundle of the jet cooling heat exchanger disclosed in this embodiment 3 is composed of two layers of serpentine pipes arranged in parallel to form multiple channels. Each layer of serpentine pipes is composed of several heat exchange tubes 4 connected end to end by an elbow 5. A fluid distributor 6 is provided between the inlet end of the heat exchange tube bundle and the cooling medium connection flange 3, and between the outlet end of the heat exchange tube bundle and the cooling medium connection flange 3. The cooling medium is evenly distributed to the two layers of serpentine pipes through the fluid distributor 6, and exchanges heat with the cooled fluid in the shell 2. After heat exchange, it enters the fluid distributor 6 through the downstream diverging pipe section 10 of the heat exchange tube 4, mixes, and then flows out of the heat exchanger. In application, multiple layers of serpentine pipes can be designed according to actual heat exchange requirements.

[0048] The working principle of the jet cooling heat exchanger disclosed in the present invention is as follows:

[0049] The pressurized working fluid enters the heat exchange tube of the jet cooler, and expands in the upstream convergent tube section to reduce pressure, cool down, increase speed and reach the speed of sound. At this time, the temperature of the working fluid is only related to the pressure and temperature when the working fluid enters the heat exchanger; then the high-speed, low-temperature working fluid enters the intermediate heat exchange tube section to absorb heat and generate cooling. Under the action of pipe wall friction and working fluid heat absorption, the pressure of the high-speed working fluid gradually increases; finally, the working fluid enters the downstream divergent tube section to reduce speed and increase pressure, and the kinetic energy is further converted into pressure energy, thereby achieving energy saving.

[0050] The low temperature of the jet cooling heat exchanger disclosed in the present invention is determined by the working conditions of the working fluid. In the external system, the pressure and temperature of the working fluid entering the jet cooling heat exchanger are adjusted through processes such as compressors, valves, and heat exchange, so that the required cooling temperature can be directly and quickly obtained in the middle heat exchange pipe section of the heat exchanger, and the cooling temperature is convenient and controllable. The expansion and cooling of the pressurized fluid are achieved through the tapered pipe section, which can achieve very low temperatures, increase the heat exchange temperature difference, obtain a large heat flux density, reduce the heat exchange area, and have a strong heat exchange capacity per unit volume. The cooling speed of the cooling working fluid increases after absorbing heat, and part of the absorbed heat can be converted into pressure energy, realizing low-temperature heat utilization and reducing the pressure drop of the heat exchanger. It can be used to recover the residual pressure in industrial fluids to generate cooling capacity. When used as an evaporator in an air-conditioning system, a throttle valve can be omitted to improve the cooling efficiency.

[0051] The above content is only for explaining the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A jet cooling heat exchanger, characterized in that: It comprises a shell (2) and a plurality of heat exchange tubes (4); A plurality of heat exchange tubes (4) are arranged in an array to form a heat exchange tube bundle, and each heat exchange tube (4) includes an upstream convergent tube section (9), an intermediate heat exchange tube section (11), and a downstream divergent tube section (10); The heat exchange tube bundle is arranged across the shell (2), and the middle heat exchange tube sections (11) of all the heat exchange tubes (4) are arranged inside the shell (2), and the upstream convergent tube section (9) and the downstream divergent tube section (10) are arranged outside the shell (2); The working medium inlet and outlet of the heat exchange tube bundle are respectively connected to the cooling working medium pipeline; The working medium inlet end and the working medium outlet end of the shell (2) are respectively connected to the cooling fluid pipeline.

2. The jet cooling heat exchanger according to claim 1, characterized in that: The heat exchange tube bundle is configured by connecting a plurality of heat exchange tubes (4) end to end in series via an elbow (5) to form a serpentine pipeline.

3. The jet cooling heat exchanger according to claim 1, characterized in that: The heat exchange tube bundle is composed of a plurality of heat exchange tubes (4) arranged in parallel to form multiple flow channels, and a fluid distributor (6) is respectively provided between the inlet end of the heat exchange tube bundle and the cooling medium connection flange (3) and between the outlet end of the heat exchange tube bundle and the cooling medium connection flange (3).

4. The jet cooling heat exchanger according to claim 1, characterized in that: The heat exchange tube bundle is composed of several layers of serpentine pipes arranged in parallel to form multiple flow channels, and each layer of serpentine pipes is composed of several heat exchange tubes (4) connected end to end by elbows (5); and a fluid distributor (6) is respectively provided between the inlet end of the heat exchange tube bundle and the cooling medium connection flange (3) and between the outlet end of the heat exchange tube bundle and the cooling medium connection flange (3).

5. The jet cooling heat exchanger according to claim 1, characterized in that: The outer wall of the intermediate heat exchange tube section (11) is provided with metal fins.

6. The jet cooling heat exchanger according to claim 5, characterized in that: The metal fins are rectangular metal fins (7) or wavy metal fins (8).

7. The jet cooling heat exchanger according to claim 5, characterized in that: The metal fins are connected and fixed to the heat exchange tubes (4) by welding or tube expansion.

8. The jet cooling heat exchanger according to claim 1, characterized in that: The intermediate heat exchange pipe section (11) is a constant diameter heat exchange pipe section or a gradually expanding heat exchange pipe section.

9. The jet cooling heat exchanger according to any one of claims 1 to 8, characterized in that: The working fluid inlet and outlet of the heat exchange tube bundle are connected to the cooling working fluid pipeline via a cooling working fluid connection flange (3), respectively; the working fluid inlet and outlet of the shell (2) are connected to the cooled fluid pipeline via a cooled fluid connection flange (1), respectively.

10. The jet cooling heat exchanger according to any one of claims 1 to 8, characterized in that: The heat exchange tube (4) and the shell (2) are fixed by welding.

Images