A heat exchanger

Abstract

This utility model relates to the field of frozen beverage manufacturing machine technology, specifically disclosing a heat exchanger suitable for use in frozen beverage manufacturing machines, comprising an inner cylinder, an outer cylinder, and an evaporator tube. The outer cylinder is spaced outside the inner cylinder, forming a sandwich cavity between them. The evaporator tube is located within the sandwich cavity, with its inlet and outlet ends leading out of the sandwich cavity. The sandwich cavity has an injection port for injecting a heat-conducting medium into it. The heat-conducting medium fills the sandwich cavity, and the evaporator tube is at least partially immersed in the heat-conducting medium. This design avoids the high-pressure operation mode where refrigerant directly fills the sandwich cavity, reducing the pressure requirements of the sandwich cavity. Furthermore, the heat-conducting medium surrounding the evaporator tube and filling the sandwich cavity allows for the transfer of cold energy from the evaporator tube to both the inner and outer cylinders, reducing reliance on the direct contact area between the evaporator tube and the cylinder wall, and improving the continuity of cold energy transfer and overall heat exchange efficiency.

Description

Technical Field

[0001] This utility model relates to the field of frozen beverage manufacturing machine technology, and in particular to a heat exchanger suitable for use in frozen beverage manufacturing machines. Background Technology

[0002] A frozen beverage making machine is a device used to turn liquid mixtures such as fruit juice and milk tea into slush-like or iced beverages, such as slush machines and ice cream machines. In this type of equipment, the heat exchanger is a crucial component for achieving slurry cooling, directly affecting the overall heat exchange efficiency and structural stability of the machine.

[0003] Existing heat exchanger structures mainly include two forms: one is a coil heat exchanger, in which copper tubes are wound and arranged between the inner and outer cylinders as evaporator tubes, and the refrigerant flows in the copper tubes and exchanges heat with the slurry; the other is a jacketed structure, in which a closed jacket cavity is formed between the inner and outer cylinders, and the refrigerant flows directly from the jacket cavity for heat exchange.

[0004] However, the heat exchange efficiency of the coiled structure is relatively low because the copper tubes and the outer cylinder are only in partial contact; while the sandwich structure can increase the heat exchange area, when the refrigerant operates under high pressure (about 2MPa) in the sandwich cavity, it is very easy to create destructive pressure on the weld between the inner and outer cylinders, which can easily lead to problems such as cylinder deformation and seal failure. Utility Model Content

[0005] (a) Technical problems to be solved

[0006] The purpose of this invention is to provide a heat exchanger that overcomes the problems of low heat exchange efficiency in existing coil-type structures, high pressure resistance in sandwich-type structures, easy deformation of the cylinder, and sealing failure.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, this utility model provides a heat exchanger, comprising an inner cylinder, an outer cylinder, and an evaporator tube. The outer cylinder is spaced outside the inner cylinder, forming a sandwich cavity between the outer cylinder and the inner cylinder. The evaporator tube is disposed within the sandwich cavity, with its inlet and outlet ends respectively leading out to the outside of the sandwich cavity. The sandwich cavity is characterized by having an injection port for injecting a heat-conducting medium into it. The heat-conducting medium fills the sandwich cavity, such that the evaporator tube is at least partially immersed in the heat-conducting medium.

[0009] Furthermore, the freezing point of the heat-conducting medium is below -10°C.

[0010] Furthermore, the thermally conductive medium includes any one or a combination of the following: ethylene glycol, aqueous ethylene glycol, silicone oil, alcohol, saline solution, or nanofluid.

[0011] Furthermore, the evaporator tubes are arranged around the outer wall of the inner cylinder, forming a cylindrical structure that is wrapped around the inner cylinder.

[0012] Furthermore, the evaporator tubes are arranged in a continuous spiral around the outer surface of the inner cylinder, with multiple spiral structures arranged sequentially along the axial direction of the inner cylinder to form the cylindrical structure; or, the evaporator tubes are arranged in an S-shaped structure that reciprocates axially within the inner cylinder, and the cylindrical structure is formed by multiple parallel bends.

[0013] Furthermore, the inner and outer cylinders are fixed by mechanical connection and are made of different materials; wherein, the inner cylinder used for heat exchange is made of metal, and the other cylinder is made of thermoplastic material.

[0014] Furthermore, the metallic material includes stainless steel or aluminum, and the thermoplastic material includes polypropylene, polycarbonate, or polyamide.

[0015] Furthermore, a sealing gasket is provided between the inner cylinder and the outer cylinder.

[0016] (iii) Compared with the prior art, the beneficial effects of this utility model are as follows.

[0017] This invention injects a heat-conducting medium into the interlayer cavity between the inner and outer cylinders, allowing the evaporator tubes to be at least partially immersed in the heat-conducting medium. The combination of the evaporator tubes and the heat-conducting medium forms an indirect heat exchange structure, avoiding the high-pressure operation mode where the refrigerant directly fills the interlayer cavity. This significantly reduces the pressure requirements of the interlayer cavity, reduces the risk of cylinder deformation, weld cracking, or seal failure due to high pressure, and improves the stability and service life of the entire machine structure.

[0018] The heat-conducting medium surrounds the evaporator tube and fills the jacket cavity, which can conduct the cold energy of the evaporator tube to the inner and outer cylinders, reducing the dependence on the direct contact area between the evaporator tube and the cylinder wall, improving the continuity of cold energy transfer and the overall heat exchange efficiency, and can buffer local heat exchange blind spots caused by installation errors or poor contact. Attached Figure Description

[0019] The accompanying drawings are provided to further understand the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation thereof.

[0020] Figure 1 This is a three-dimensional structural diagram of an embodiment of the present utility model.

[0021] Figure 2 This is a cross-sectional structural diagram of an embodiment of the present invention.

[0022] Figure 3This is a schematic diagram of a cylindrical structure of an evaporator tube in one embodiment of the present invention.

[0023] Figure 4 This is a schematic diagram of another cylindrical structure of the evaporator tube in one embodiment of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clear and complete, the embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0025] In the description of this utility model, it should be noted that the terms "center", "middle", "upper", "lower", "left", "right", "inner", "outer", "top", "bottom", "side", "vertical", "horizontal", "first", "second", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] Please see Figure 1 and Figure 2 This embodiment provides a heat exchanger suitable for a frozen beverage manufacturing machine. The heat exchanger includes an inner cylinder 1, an outer cylinder 2, and an evaporator 3. The outer cylinder 2 is spaced outside the inner cylinder 1, forming a sandwich cavity 4 between them.

[0028] The evaporator tube 3 is disposed in the jacket cavity 4, with its inlet end 301 and outlet end 302 leading out to the outside of the jacket cavity 4 for connection with the refrigerant piping system.

[0029] The interlayer cavity 4 is provided with an injection port 401 for injecting the heat-conducting medium 5; after injection, the heat-conducting medium 5 fills the interlayer cavity 4, so that the evaporation tube 3 is at least partially immersed in it.

[0030] In this embodiment, the heat-conducting medium 5 refers to a heat exchange material that maintains good fluidity within the operating temperature range and possesses excellent thermal conductivity and chemical stability. It may include liquids, suspensions, or other fluid heat-conducting substances. Since the refrigerant in the evaporator tube 3 may cool the jacketed cavity 4 to several degrees below zero or even lower temperatures during operation of the frozen beverage maker, the heat-conducting medium 5 must remain liquid or possess sufficient fluidity at low temperatures to ensure effective heat transfer and maintain stable system operation. Preferably, the freezing point of the heat-conducting medium 5 is below -10°C to ensure it remains fluid at the operating temperature of the frozen beverage maker, thereby avoiding a decrease in heat exchange efficiency.

[0031] Specifically, the heat transfer medium 5 may include common low-temperature heat transfer liquids such as ethylene glycol, aqueous ethylene glycol (ethylene glycol aqueous solution), silicone oil, alcohol (ethanol aqueous solution), and brine (sodium chloride aqueous solution), or mixtures thereof. These liquids typically have a freezing point below -20°C, which can effectively prevent problems such as solidification, crystallization, or blockage at low temperatures, thereby ensuring heat exchange efficiency and operational reliability.

[0032] In addition, the heat transfer medium 5 can also be a novel material suitable for extremely low temperature heat exchange, such as nanofluids. Nanofluids refer to a suspension liquid formed by uniformly dispersing high thermal conductivity nanoparticles (such as metals, metal oxides, carbon nanotubes, etc.) in a traditional carrier liquid. It not only has higher heat transfer efficiency, but also good thermal stability and low temperature fluidity, and is suitable for heat exchange environments below -30℃.

[0033] Of course, this embodiment does not limit the specific type of heat-conducting medium 5. Any low-temperature fluid medium that has the above characteristics and is suitable for heat transfer can be applied.

[0034] During operation, the refrigerant flows in the evaporator tube 3, and its cooling capacity is uniformly transferred to the walls of the inner cylinder 1 and / or outer cylinder 2 through the heat transfer medium 5, achieving efficient cooling of the slurry. This indirect heat exchange structure reduces the pressure requirements of the jacket cavity 4, minimizing the risk of cylinder deformation or weld damage caused by high pressure, thus improving structural reliability and service life. Furthermore, it reduces the reliance on the direct contact area between the evaporator tube 3 and the cylinder wall, thereby enhancing overall heat exchange efficiency.

[0035] Meanwhile, the heat transfer medium 5 also plays a role in heat capacity regulation and buffering in the system. Even if the evaporator tube 3 is not completely attached to the cylinder wall, as long as it is partially immersed in the medium, a good cooling effect can be achieved, effectively mitigating the heat exchange blind zone and efficiency fluctuations caused by installation errors or uneven pipe distribution.

[0036] In this embodiment, the evaporator tube 3 is arranged around the outer surface of the inner cylinder 1 to form a nested structure, thereby constituting a cylindrical heat exchanger. This structure helps to extend the arrangement length of the evaporator tube 3 in the jacket cavity 4, thereby extending the refrigerant flow path and releasing cold energy more fully, thus improving the overall refrigeration efficiency.

[0037] The evaporator tube 3 can be arranged in a cylindrical structure in various ways. For example, as... Figure 3 As shown, the evaporator tube 1 is arranged in a continuous spiral around the outer surface of the inner cylinder 1, with multiple spiral turns arranged sequentially along the axial direction of the inner cylinder 1, forming an overall cylindrical structure; or as shown... Figure 4 As shown, the evaporator tube 3 is arranged in an S-shaped structure with the inner cylinder 1 reciprocating axially, and is composed of multiple parallel bends forming a cylindrical structure. Of course, those skilled in the art will understand that the specific arrangement of the evaporator tube 3 is not limited to the structure shown above, as long as it can form an effective cylindrical structure in a similar manner, it is acceptable, and no limitation is made here.

[0038] Since the interlayer cavity 4 is not a pressure-bearing component, the inner cylinder 1 and the outer cylinder 2 can be fixed by mechanical connection, such as threaded connection, snap-fit ​​connection or screw fixing, to replace the traditional welding process, thereby simplifying the manufacturing process and reducing production costs.

[0039] In terms of materials, the inner cylinder 1 and the outer cylinder 2 can be made of the same or different materials. For example, both can be made of metal materials with good thermal conductivity, such as stainless steel or aluminum, to improve heat exchange efficiency; in other embodiments, the cylinder used for heat exchange is made of metal material, and the other cylinder is made of thermoplastic material, such as polypropylene (PP), polycarbonate (PC) or polyamide (PA), to optimize the overall performance and cost by taking advantage of its heat insulation and molding properties.

[0040] The above design is applicable to two mainstream structures of frozen beverage machines currently on the market: one is heat exchange between the inner cylinder and the slurry, and the other is heat exchange between the outer cylinder and the slurry.

[0041] To further improve the sealing performance of the interlayer cavity 4 and prevent leakage of the heat transfer medium 5, a sealing gasket (not shown) is also provided at the mechanical connection between the inner cylinder 1 and the outer cylinder 2, which effectively improves the safety and reliability of the equipment operation.

[0042] It should be noted that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A heat exchanger, comprising an inner cylinder, an outer cylinder, and evaporator tubes, wherein the outer cylinder is spaced outside the inner cylinder to form a sandwich cavity between the outer cylinder and the inner cylinder, and the evaporator tubes are disposed within the sandwich cavity, with their inlet and outlet ends respectively leading out to the outside of the sandwich cavity, characterized in that: The interlayer cavity is provided with an injection port for injecting a heat-conducting medium into the interlayer cavity. The heat-conducting medium fills the interlayer cavity so that the evaporator tube is at least partially immersed in the heat-conducting medium.

2. The heat exchanger according to claim 1, characterized in that: The freezing point of the heat-conducting medium is below -10°C.

3. The heat exchanger according to claim 2, characterized in that: The thermally conductive medium includes any one or a combination of the following: ethylene glycol, aqueous ethylene glycol, silicone oil, alcohol, saline solution, or nanofluid.

4. The heat exchanger according to claim 1, characterized in that: The evaporation tubes are arranged around the outer wall of the inner cylinder, forming a cylindrical structure that is wrapped around the inner cylinder.

5. The heat exchanger according to claim 4, characterized in that: The evaporator tubes are arranged in a continuous spiral around the outer surface of the inner cylinder, with multiple spiral turns arranged sequentially along the axial direction of the inner cylinder to form the cylindrical structure; or... The evaporator tubes are arranged in an S-shaped structure with the inner cylinder reciprocating axially, and the cylindrical structure is composed of multiple parallel bends.

6. The heat exchanger according to claim 1, characterized in that: The inner and outer cylinders are fixed by mechanical connection and are made of different materials; wherein, the inner cylinder used for heat exchange is made of metal and the other cylinder is made of thermoplastic material.

7. The heat exchanger according to claim 6, characterized in that: The metallic material includes stainless steel or aluminum, and the thermoplastic material includes polypropylene, polycarbonate, or polyamide.

8. The heat exchanger according to claim 6, characterized in that: A sealing gasket is provided between the inner cylinder and the outer cylinder.

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