Cascade heat exchange device and heat exchange system

Abstract

The invention provides a cascade heat exchange device and a heat exchange system, relates to the technical field of heat exchange equipment, and aims to optimize the structure of the heat exchange device to a certain extent and improve the safety and heat exchange efficiency of the whole device. The cascade heat exchange device comprises a main cavity, the first end of the main cavity is an inlet, the second end of the main cavity is an outlet, and a third medium enters from the inlet of the main cavity and is discharged from the outlet of the main cavity; a first medium cavity and a second medium cavity are formed in the main cavity, an inlet and an outlet of the first medium cavity both penetrate through the main cavity, and a first medium flows from the inlet to the outlet of the first medium cavity; an inlet and an outlet of the second medium cavity both penetrate through the main cavity, the second medium flows from the inlet of the second medium cavity to the outlet, the flowing direction of the first medium is opposite to that of the second medium, and the flowing direction of the third medium is the same as that of the second medium and opposite to that of the first medium.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchange equipment, and in particular to a cascade heat exchange device and a heat exchange system. Background Art

[0002] As people's requirements for living environment increase, the demand for heating in winter and cooling in summer is gradually increasing. As the efforts to protect the environment and reduce carbon emissions gradually increase, more and more regions are using distributed heating methods such as air source heat pumps, especially for winter heating. The use of conventional refrigerant air source heat pumps is limited by environmental conditions and needs to be replaced by more environmentally friendly and low-temperature refrigerants. Therefore, the overall heat exchange device needs to be able to withstand high pressure and avoid leakage when the refrigerant is in the gaseous stage. However, the current heat exchange device cannot effectively ensure the heat exchange efficiency while avoiding the problem of gaseous refrigerant leaking into the environment and polluting the environment.

[0003] Therefore, in the development of new refrigerants, cascade units have become an important development direction of air source heat pumps. Therefore, a new heat exchange system suitable for cascade units is needed to solve the problems existing in the prior art to a certain extent. Summary of the invention

[0004] The object of the present invention is to provide a cascade heat exchange device and a heat exchange system, so as to optimize the structure of the heat exchange device to a certain extent and improve the overall device safety and heat exchange efficiency.

[0005] The present invention provides a cascade heat exchange device, comprising a main cavity, wherein a first end of the main cavity is an inlet, and a second end is an outlet, a third medium enters from the inlet of the main cavity and is discharged from the outlet of the main cavity; a first medium cavity and a second medium cavity are formed in the main cavity, the inlet and the outlet of the first medium cavity are both arranged through the main cavity, and the first medium flows from the inlet to the outlet of the first medium cavity; the inlet and the outlet of the second medium cavity are both arranged through the main cavity, and the second medium flows from the inlet to the outlet of the second medium cavity, and the flow direction of the first medium is opposite to the flow direction of the second medium, and the flow direction of the third medium is the same as the flow direction of the second medium and opposite to the flow direction of the first medium.

[0006] The first medium cavity, the second medium cavity and the main cavity are all cylindrical structures, the second medium cavity is located in the main cavity, the first medium cavity is located in the second medium cavity, and the inlet and outlet of the second medium cavity both extend outward through the wall of the main cavity.

[0007] Specifically, the length of the first medium cavity is not less than the length of the second medium cavity, and both ends of the second medium cavity are sealed and connected to the first medium cavity; the length of the first medium cavity is not greater than the length of the main cavity, and the inlet and outlet of the first medium cavity both extend outward through the wall of the main cavity.

[0008] The first medium cavity is arranged through the second medium cavity, and the second medium cavity is sealed and connected to the first medium cavity; a baffle is arranged in the second medium cavity, and the baffle divides the first medium cavity into a reflux cavity and a mainstream cavity, the wall of the second medium cavity is formed with an outlet corresponding to the reflux cavity, the wall of the second medium cavity is formed with an inlet connected to the mainstream cavity, and the mainstream cavity is connected to the reflux cavity.

[0009] Specifically, the baffle includes a first baffle and a second baffle, and the first baffle and the second baffle form a first reflux chamber and a second reflux chamber connected to the main flow chamber with the wall of the second medium chamber, and the outlet of the second medium chamber corresponds to the first reflux chamber and the second reflux chamber one by one, and the outlet connected to the first reflux chamber and the outlet connected to the second reflux chamber are arranged opposite to each other along the radial direction of the second medium chamber and are arranged close to the inlet of the second medium chamber; the flow direction of the second medium in the first reflux chamber and the second reflux chamber is opposite to the flow direction of the main flow chamber, and the flow direction of the third medium in the main chamber is opposite to the flow direction of the second medium in the first reflux chamber and the second reflux chamber.

[0010] Wherein, a third baffle and a fourth baffle are provided in the main cavity, and the third baffle and the fourth baffle divide the main cavity into a first liquid-transfer cavity and a second liquid-transfer cavity, the first liquid-transfer cavity is connected with the second liquid-transfer cavity, and the inlet of the main cavity is connected with the first liquid-transfer cavity, and the flow direction of the third medium in the first liquid-transfer cavity is opposite to the flow direction of the second medium in the second medium cavity; the outlet of the main cavity is connected with the second liquid-transfer cavity, and the flow direction of the third medium in the second liquid-transfer cavity is opposite to the flow direction of the third medium in the first liquid-transfer cavity.

[0011] Specifically, the main cavity and the second medium cavity are both coil structures, and the first medium cavity is a straight tube structure, the second medium cavity is coiled outside the first medium cavity along the extension direction of the first medium cavity, and the main cavity is coiled outside the second medium cavity.

[0012] Further, the second medium cavity includes an inner tube body and an outer tube body, the inner tube body is located in the outer tube body and forms a double-layer sleeve structure; the first medium cavity is located between the inner tube body and the outer tube body, and the first medium cavity is sealed and connected to the inner tube body, the main cavity is located outside the outer tube body, and an outlet and an inlet passing through the outer tube body and the main cavity are formed on the first medium cavity, and the outlet and the inlet are relatively arranged at two ends of the first medium cavity.

[0013] Furthermore, the third medium is water, the first medium is carbon dioxide, and the second medium is R600a.

[0014] Compared with the prior art, the cascade heat exchange device provided by the present invention has the following advantages:

[0015] The cascade heat exchange device provided by the present invention comprises a main cavity, wherein the first end of the main cavity is an inlet, and the second end is an outlet, a third medium enters from the inlet of the main cavity and is discharged from the outlet of the main cavity; a first medium cavity and a second medium cavity are formed in the main cavity, the inlet and the outlet of the first medium cavity are both arranged through the main cavity, and the first medium flows from the inlet of the first medium cavity to the outlet; the inlet and the outlet of the second medium cavity are both arranged through the main cavity, and the second medium flows from the inlet of the second medium cavity to the outlet, and the flow direction of the first medium is opposite to that of the second medium, and the flow direction of the third medium is the same as that of the second medium and opposite to that of the first medium.

[0016] From this analysis, it can be known that the main cavity can carry both the first medium cavity and the second medium cavity, and the flow of the third medium can be realized through the cavity formed between the main cavity and the second medium cavity. Accordingly, the corresponding flow of the third medium and the first medium can be realized through the first medium cavity and the second medium cavity, and since the flow direction of the first medium in the first medium cavity is opposite to the flow direction of the second medium in the second medium cavity in this application, and at the same time, the flow direction of the third medium in the main cavity is the same as that of the second medium, and is opposite to the flow direction of the second medium, therefore, in the actual heat dissipation process, since the flow directions of the second medium and the first medium are opposite, the second medium can fully exchange heat with the first medium, and the third medium can fully exchange heat with the first medium, and further exchange heat with the second medium, thereby utilizing the opposite flow direction to improve the heat exchange efficiency.

[0017] Since the first medium cavity in the present application is located in the main cavity, it can be fully surrounded by the main cavity, and the main cavity is also filled with a flowing third medium. Therefore, even if the first medium cavity has local leakage problems due to long-term use or high-pressure use, the first medium in the first medium cavity will not leak to the external environment, thereby ensuring the safety of the overall device to a certain extent.

[0018] In addition, the present invention also provides a heat exchange system, including the above-mentioned cascade heat exchange device.

[0019] The cascade heat exchange system provided in the present application can carry three kinds of media, and the structure of the present application can realize different flow directions of the three kinds of media, thereby achieving better heat exchange efficiency and ensuring the safety of the overall device, reducing the risk of leakage of the medium to the external environment, and thus ensuring the stable operation of the overall heat exchange system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic structural diagram of a first cascade heat exchange device from a first perspective provided by an embodiment of the present invention;

[0022] Figure 2 A cross-sectional view of a first cascade heat exchange device provided in an embodiment of the present invention;

[0023] Figure 3 A schematic structural diagram of a second cascade heat exchange device from a first perspective provided by an embodiment of the present invention;

[0024] Figure 4 A cross-sectional view of a second cascade heat exchange device provided by an embodiment of the present invention;

[0025] Figure 5 A partial cross-sectional view of a third cascade heat exchange device provided in an embodiment of the present invention;

[0026] Figure 6 A schematic structural diagram of a fourth cascade heat exchange device from a first perspective provided by an embodiment of the present invention;

[0027] Figure 7 A cross-sectional view of a fourth cascade heat exchange device provided in an embodiment of the present invention.

[0028] In the figure: 1-main cavity; 2-first medium cavity; 3-second medium cavity; 301-first baffle; 3011-first reflux cavity; 302-second baffle; 3021-second reflux cavity; 303-inner tube body; 304-outer tube body; 4-inlet; 5-outlet. DETAILED DESCRIPTION

[0029] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0030] In the description of the embodiments of the present application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or are the positions or positional relationships in which the invented product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0031] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0032] In the description of the embodiments of the present application, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation", "connection", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0034] For ease of description, spatial relative terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another element as shown in the drawings. Such spatial relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings.

[0035] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "include", "comprise" and "have" list the stated features, quantities, operations, components, elements and / or their combinations that exist, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and / or their combinations.

[0036] Variations in the shapes shown in the drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the drawings but include variations in shapes that occur during manufacturing.

[0037] The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application. In addition, the technical solutions between the various embodiments may be combined with each other, but must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be considered that the combination of such technical solutions does not exist and is not within the scope of protection required by the present application.

[0038] like Figure 1-Figure 7 As shown, the present invention provides a cascade heat exchange device, including a main cavity 1, a first end of the main cavity 1 is an inlet 4, and a second end is an outlet 5, a third medium enters through the inlet 4 of the main cavity 1, and is discharged from the outlet 5 of the main cavity 1; a first medium cavity 2 and a second medium cavity 3 are formed in the main cavity 1, the inlet 4 and the outlet 5 of the first medium cavity 2 are both arranged through the main cavity 1, and the first medium flows from the inlet 4 of the first medium cavity 2 to the outlet 5; the inlet 4 and the outlet 5 of the second medium cavity 3 are both arranged through the main cavity 1, and the second medium flows from the inlet 4 of the second medium cavity 3 to the outlet 5, and the flow direction of the first medium is opposite to that of the second medium, and the flow direction of the third medium is the same as that of the second medium and opposite to that of the first medium.

[0039] Compared with the prior art, the cascade heat exchange device provided by the present invention has the following advantages:

[0040] The cascade heat exchange device provided by the present invention can carry the first medium cavity 2 and the second medium cavity 3 through the main cavity 1, and can also realize the flow of the third medium through the cavity formed between the main cavity 1 and the second medium cavity 3. Accordingly, the corresponding flow of the third medium and the first medium can be realized through the first medium cavity 2 and the second medium cavity 3, and since the flow direction of the first medium in the first medium cavity 2 is opposite to the flow direction of the second medium in the second medium cavity 3 in the present application, and at the same time, the flow direction of the third medium in the main cavity 1 is the same as that of the second medium, and is opposite to the flow direction of the second medium, therefore, in the actual heat dissipation process, since the flow directions of the second medium and the first medium are opposite, the second medium can fully exchange heat with the first medium, and the third medium can fully exchange heat with the second medium, and further exchange heat with the second medium, thereby utilizing the opposite flow direction to improve the heat exchange efficiency.

[0041] Since the first medium cavity 2 in the present application is located in the main cavity 1, it can be fully surrounded by the main cavity 1, and the main cavity 1 is also filled with a flowing third medium. Therefore, even if the first medium cavity 2 has local leakage problems due to long-term use or high-pressure use, the first medium in the first medium cavity 2 will not leak to the external environment, thereby ensuring the safety of the overall device to a certain extent.

[0042] like Figure 1 Combination Figure 2 Based on the above structure, the present application provides a first structure of a cascade heat exchange device, wherein the first medium chamber 2, the second medium chamber 3 and the main chamber 1 are all cylindrical structures, the second medium chamber 3 is located in the main chamber 1, the first medium chamber 2 is located in the second medium chamber 3, and the inlet 4 and the outlet 5 of the second medium chamber 3 both extend outward through the wall of the main chamber 1.

[0043] In this embodiment, the first medium cavity 2 is located in the innermost layer, the second medium cavity 3 is sleeved outside the first medium cavity 2, and the second medium cavity 3 is sealed and connected to the first medium cavity 2. The inlet 4 and the outlet 5 of the second medium cavity 3 both extend to the outside through the main cavity 1, and the inlet 4 and the outlet 5 of the second medium cavity 3 are relatively arranged at the two ends of the second medium cavity 3. Figure 2 For example, when the left side of the innermost first medium cavity 2 is the inlet 4 and the right side is the outlet 5, that is, when the first medium flows from left to right, the right side of the second medium cavity 3 is the inlet 4 and the left side is the outlet 5, so that the flow direction of the first medium is opposite to the flow direction of the second medium.

[0044] Accordingly, to ensure that the flow direction of the third medium is opposite to that of the second medium, the left side of the main cavity 1 in the present application is the inlet 4 and the right side is the outlet 5, so that the third medium flows from left to right, achieving efficient heat exchange of the overall device.

[0045] Preferably, in this embodiment, the length of the first medium cavity 2 is not less than the length of the second medium cavity 3, and both ends of the second medium cavity 3 are sealed and connected to the first medium cavity 2; the length of the first medium cavity 2 is not greater than the length of the main cavity 1, and the inlet 4 and the outlet 5 of the first medium cavity 2 both extend outward through the wall of the main cavity 1.

[0046] Further preferably, in the present application, the length of the second medium cavity 3 is less than the length of the first medium cavity 2, and therefore, both ends of the second medium cavity 3 are closed ends, achieving isolation and sealing with the first medium cavity 2, so that the second medium can only flow in the second medium cavity 3, and ensure that the first medium can only flow in the first medium cavity 2.

[0047] Once the first medium cavity 2 leaks, the third medium will only leak into the second medium cavity 3 or the main cavity 1 and will not leak into the external environment, thereby ensuring the stability of the operation of the entire device.

[0048] In this embodiment, the third medium is water, the first medium is carbon dioxide coolant, that is, R744 coolant, and the second medium is R600a coolant. When the first medium enters the first medium cavity 2, it is in a high-temperature and high-pressure gas state. After heat exchange with the second medium, it becomes liquid. After the temperature is transferred to the second medium, the temperature is transferred through heat exchange between the third medium and the second medium. In addition, since the length of the main cavity 1 in this application is greater than the length of the first medium cavity 2, the third medium in the main cavity 1 also has a part that directly exchanges heat with the first medium in the first medium cavity 2, so that the heat exchange efficiency can be guaranteed, so that the heat carried by the first medium can be transferred to the third medium more, thereby heating the water and meeting the heating demand.

[0049] Alternatively, if Figure 3 Combination Figure 4 As shown, a second embodiment of the cascade heat exchange device is provided, wherein the first medium chamber 2 is arranged through the second medium chamber 3, and the second medium chamber 3 is sealed and connected to the first medium chamber 2; a baffle is arranged in the second medium chamber 3, and the baffle divides the first medium chamber 2 into a reflux chamber and a mainstream chamber, the wall of the second medium chamber 3 is formed with an outlet 5 corresponding to the reflux chamber, the wall of the second medium chamber 3 is formed with an inlet 4 connected to the mainstream chamber, and the mainstream chamber is connected to the reflux chamber.

[0050] In this embodiment, the first medium chamber 2, the second medium chamber 3 and the main chamber 1 in the present application are all flat tube structures, that is, the cross-sections of the first medium chamber 2, the second medium chamber 3 and the main chamber 1 are all rectangular, so that it is convenient to set the baffle, and the baffle formed in the second medium chamber 3 can separate the second medium chamber 3 into a mainstream chamber and a reflux chamber. When the second medium enters from the inlet 4 of the second medium chamber 3, it first flows in the mainstream chamber and then flows from the mainstream chamber to the reflux chamber. In this embodiment, the outlet 5 of the second medium chamber 3 is connected to the reflux chamber, thereby realizing the discharge of the second medium.

[0051] It can be understood that, since a baffle is installed in the second medium cavity 3 in this embodiment, the time that the second medium stays in the second medium cavity 3 can be increased, thereby increasing the heat exchange time and improving the heat exchange effect. In this embodiment, heat is transferred from the first medium to the second medium in the mainstream cavity, and then, before the second medium in the mainstream cavity enters the reflux cavity, a portion of the heat can be transferred to the second medium in the reflux cavity during the flow process, and the second medium flowing into the reflux cavity exchanges heat with the third medium in the main cavity 1, completing the heat transfer and achieving the heating of the third medium water.

[0052] Preferably, if Figure 4 As shown, the baffle in the present application includes a first baffle 301 and a second baffle 302, and the first baffle 301 and the second baffle 302 form a first reflux chamber 3011 and a second reflux chamber 3021 connected to the main flow chamber with the wall of the second medium chamber 3, and the outlet 5 of the second medium chamber 3 corresponds to the first reflux chamber 3011 and the second reflux chamber 3021 one by one, and the outlet 5 connected to the first reflux chamber 3011 and the outlet 5 connected to the second reflux chamber 3021 are arranged opposite to each other along the radial direction of the second medium chamber 3, and are arranged close to the inlet 4 of the second medium chamber 3; the flow direction of the second medium in the first reflux chamber 3011 and the second reflux chamber 3021 is opposite to the flow direction of the main flow chamber, and the flow direction of the third medium in the main chamber 1 is opposite to the flow direction of the second medium in the first reflux chamber 3011 and the second reflux chamber 3021.

[0053] The first baffle 301 and the second baffle 302 can form a first reflux cavity 3011 and a second reflux cavity 3021 respectively, so that the coolant in the second medium cavity 3 flows more stably and evenly, and the amount of refluxed medium is larger, thereby improving the heat exchange efficiency.

[0054] Accordingly, in the present application, the second medium cavity 3 is formed with two outlets 5, which correspond to the first reflux cavity 3011 and the second reflux cavity 3021, and the inlet 4 can be one, so as to ensure that the second medium enters the mainstream cavity, and Figure 4As shown, in this embodiment, one of the outlets 5 corresponding to the second medium cavity 3 is arranged close to the inlet 4, and the other outlet 5 is arranged opposite to the outlet 5 close to the inlet 4, that is, the centers of the two outlets 5 of the second medium cavity 3 are collinear.

[0055] The third embodiment of the present application is not shown in the figure, wherein a third baffle and a fourth baffle are provided in the main cavity 1, and the third baffle and the fourth baffle divide the main cavity 1 into a first liquid passage cavity and a second liquid passage cavity, the first liquid passage cavity is connected with the second liquid passage cavity, and the inlet 4 of the main cavity 1 is connected with the first liquid passage cavity, and the flow direction of the third medium in the first liquid passage cavity is opposite to the flow direction of the second medium in the second medium cavity 3; the outlet 5 of the main cavity 1 is connected with the second liquid passage cavity, and the flow direction of the third medium in the second liquid passage cavity is opposite to the flow direction of the third medium in the first liquid passage cavity.

[0056] This embodiment also realizes the reflux of the medium by setting a baffle, but in this embodiment, the third baffle and the fourth baffle are formed in the main cavity 1. Therefore, the structure of the first medium cavity 2 and the second medium cavity 3 in this application can still adopt the first medium cavity 2 and the second medium cavity 3 in the first embodiment, and the structure of the main cavity 1 can refer to the structural form of setting the baffle in the second medium cavity 3 in the second embodiment. By setting the third baffle and the fourth baffle in the main cavity 1, two liquid return cavities can be formed in the main cavity 1, so that the third medium can be in a reflux state, the retention time of the third medium in the main cavity 1 is increased, the heat exchange time is increased, and the heat exchange effect is improved.

[0057] like Figure 5 As shown, the present application further provides a third structural form of a cascade heat exchange device, wherein the main cavity 1 and the second medium cavity 3 are both coil structures, and the first medium cavity 2 is a straight tube structure, the second medium cavity 3 is coiled outside the first medium cavity 2 along the extension direction of the first medium cavity 2, and the main cavity 1 is coiled outside the second medium cavity 3.

[0058] Understandably, Figure 5 Only a partial structural diagram is shown. The inner second medium cavity 3 is coiled outside the first medium cavity 2, and the main cavity 1 is coiled outside the second medium cavity 3. The coiled second medium cavity 3 and the main cavity 1 can further increase the flow formation of the medium, thereby increasing the heat exchange time and improving the heat exchange effect.

[0059] The figure does not show the inlet 4 and the outlet 5 of the second medium chamber 3. In the present embodiment, since there is still a certain interval between the main chamber 1 and the first medium chamber 2, the inlet 4 and the outlet 5 can be extended to the ends of the main chamber 1 and the first medium chamber 2 by using the pipe structure, so as to facilitate the connection with the valve and the external pipeline.

[0060] It should be supplemented here that, in this embodiment, the inlet 4 and outlet 5 of the second medium cavity 3 can also directly pass through the main cavity 1, and the main cavity 1 can form a avoidance corresponding to the inlet 4 and outlet 5 positions of the second medium cavity 3 to ensure the continuity of the main cavity 1.

[0061] like Figure 6 Combination Figure 7 As shown, a fourth structural form of a cascade heat exchange device is provided, wherein the second medium cavity 3 comprises an inner tube body 303 and an outer tube body 304, wherein the inner tube body 303 is located inside the outer tube body 304 and forms a double-layer sleeve structure; the first medium cavity 2 is located between the inner tube body 303 and the outer tube body 304, and the first medium cavity 2 is sealedly connected to the inner tube body 303, the main cavity 1 is located outside the outer tube body 304, and an outlet 5 and an inlet 4 passing through the outer tube body 304 and the main cavity 1 are formed on the first medium cavity 2, and the outlet 5 and the inlet 4 are relatively arranged at two ends of the first medium cavity 2.

[0062] In this embodiment, the inner tube body 303 and the outer tube body 304 are both cylindrical structures, and the second medium flows through the inner cavity of the inner tube body 303 into the chamber between the inner tube body 303 and the outer tube body 304, and Figure 7 Taking the illustrated structural state as an example, when the second medium enters from the left end of the inner tube body 303 and flows to the right end, it can enter the chamber between the inner tube body 303 and the outer tube body 304 and flow back under the guidance of the outer tube body 304.

[0063] And as Figure 7 As shown, the first medium cavity 2 is located in the cavity between the inner tube body 303 and the outer tube body 304, and the wall of the first medium cavity 2 is sealed and connected to the right end of the inner tube body 303, thereby forming a sealed first medium cavity 2, and the third medium flows in the second medium cavity 3, and completes heat exchange through the inner cavity of the inner tube body 303 and the second medium flowing in the cavity between the inner tube body 303 and the outer tube body 304. Since the second medium in the cavity between the inner tube body 303 and the outer tube body 304 can exchange heat with the third medium in the outermost main cavity 1, the purpose of heating the third medium can be achieved.

[0064] In this embodiment, the second medium undergoes a heat exchange once in the inner cavity of the inner tube body 303 and can undergo a second heat exchange after flowing between the inner tube body 303 and the outer tube body 304 . Therefore, the heat exchange is more sufficient, thereby improving the heat exchange efficiency to a certain extent.

[0065] It is necessary to add here that Figure 6 The semicircular cover plate structure visible from the middle end is actually the seal of the end, and a part of the sealing plate is cut off for better display of the internal structure.

[0066] Furthermore, the third medium is water, the first medium is carbon dioxide, and the second medium is R600a.

[0067] The ultimate goal of the present application is to increase the temperature of the third medium, namely water. Therefore, in the above scheme, water is located in the outermost layer for heat exchange.

[0068] In addition, the present invention also provides a heat exchange system, including the above-mentioned cascade heat exchange device.

[0069] The cascade heat exchange system provided in the present application can carry three kinds of media, and the structure of the present application can realize different flow directions of the three kinds of media, thereby achieving better heat exchange efficiency and ensuring the safety of the overall device, reducing the risk of leakage of the medium to the external environment, and thus ensuring the stable operation of the overall heat exchange system.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A cascade heat exchange device, characterized in that: It comprises a main cavity, wherein the first end of the main cavity is an inlet, the second end is an outlet, the third medium enters through the inlet of the main cavity and is discharged from the outlet of the main cavity; A first medium cavity and a second medium cavity are formed in the main cavity, an inlet and an outlet of the first medium cavity are both arranged through the main cavity, and the first medium flows from the inlet to the outlet of the first medium cavity; The inlet and outlet of the second medium cavity are both arranged through the main cavity, the second medium flows from the inlet to the outlet of the second medium cavity, and the flow direction of the first medium is opposite to the flow direction of the second medium, and the flow direction of the third medium is the same as the flow direction of the second medium and opposite to the flow direction of the first medium.

2. The cascade heat exchange device according to claim 1, characterized in that: The first medium cavity, the second medium cavity and the main cavity are all cylindrical structures. The second medium cavity is located in the main cavity, the first medium cavity is located in the second medium cavity, and the inlet and outlet of the second medium cavity both extend outward through the wall of the main cavity.

3. The cascade heat exchange device according to claim 2, characterized in that: The length of the first medium cavity is not less than the length of the second medium cavity, and both ends of the second medium cavity are sealed and connected to the first medium cavity; The length of the first medium cavity is not greater than the length of the main cavity, and the inlet and outlet of the first medium cavity both extend outward through the wall of the main cavity.

4. The cascade heat exchange device according to claim 1, characterized in that: The first medium cavity is arranged through the second medium cavity, and the second medium cavity is sealed and connected to the first medium cavity; A baffle is provided in the second medium cavity, and the baffle divides the first medium cavity into a reflux cavity and a mainstream cavity. The wall of the second medium cavity forms an outlet corresponding to the reflux cavity, and the wall of the second medium cavity forms an inlet connected to the mainstream cavity, and the mainstream cavity is connected to the reflux cavity.

5. The cascade heat exchange device according to claim 4, characterized in that: The baffle comprises a first baffle and a second baffle, the first baffle and the second baffle and the wall of the second medium cavity form a first reflux cavity and a second reflux cavity connected to the main cavity, the outlet of the second medium cavity corresponds to the first reflux cavity and the second reflux cavity one by one, and the outlet connected to the first reflux cavity and the outlet connected to the second reflux cavity are arranged opposite to each other along the radial direction of the second medium cavity and are arranged close to the inlet of the second medium cavity; The flow direction of the second medium in the first reflux chamber and the second reflux chamber is opposite to that of the main chamber, and the flow direction of the third medium in the main chamber is opposite to that of the second medium in the first reflux chamber and the second reflux chamber.

6. The cascade heat exchange device according to claim 1, characterized in that: A third baffle and a fourth baffle are provided in the main chamber, and the third baffle and the fourth baffle divide the main chamber into a first liquid passage chamber and a second liquid passage chamber, the first liquid passage chamber is connected with the second liquid passage chamber, and the inlet of the main chamber is connected with the first liquid passage chamber, and the flow direction of the third medium in the first liquid passage chamber is opposite to the flow direction of the second medium in the second medium chamber; The outlet of the main cavity is communicated with the second liquid-transfer cavity, and the flow direction of the third medium in the second liquid-transfer cavity is opposite to the flow direction of the third medium in the first liquid-transfer cavity.

7. The cascade heat exchange device according to claim 1, characterized in that: The main cavity and the second medium cavity are both coil structures, and the first medium cavity is a straight tube structure. The second medium cavity is coiled outside the first medium cavity along the extension direction of the first medium cavity, and the main cavity is coiled outside the second medium cavity.

8. The cascade heat exchange device according to claim 1, characterized in that: The second medium cavity comprises an inner tube body and an outer tube body, wherein the inner tube body is located inside the outer tube body and forms a double-layer sleeve structure; The first medium cavity is located between the inner tube body and the outer tube body, and the first medium cavity is sealed and connected to the inner tube body. The main cavity is located outside the outer tube body. An outlet and an inlet passing through the outer tube body and the main cavity are formed on the first medium cavity, and the outlet and the inlet are relatively arranged at two ends of the first medium cavity.

9. The cascade heat exchange device according to claim 1, characterized in that: The third medium is water, the first medium is carbon dioxide, and the second medium is R600a.

10. A heat exchange system, characterized in that: A cascade heat exchange device comprising any one of claims 1 to 9.

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