Heat exchanger and cascade heat pump system

Abstract

The present application discloses a heat exchanger and a cascade heat pump system. The heat exchanger comprises a heat exchanger tube, a heat conduction tube, and a heat exchange tube, both the heat exchanger tube and the heat conduction tube exchange heat with the heat exchange tube, and the heat exchanger tube further exchanges heat with the heat conduction tube. According to the heat exchanger and the cascade heat pump system of the present application, good heat exchange effect is achieved.

Description

Heat exchanger and cascade heat pump system Technical Field

[0001] The present application relates to the technical field of heat pumps, and in particular to a heat exchanger and a cascade heat pump system. Background Art

[0002] Currently, conventional heat exchangers typically have only two pipes: one for the refrigerant and the other for the medium to be exchanged. This allows the refrigerant and the medium to be exchanged to exchange heat, heating or cooling the medium. Conventional heat exchangers offer a single heat exchange mechanism, and their heating or cooling performance remains to be improved.

[0003] Therefore, improvements are needed to at least partially solve the above problems.

[0004] Summary of the Invention

[0005] The Summary of the Invention introduces a series of simplified concepts that will be further described in the Detailed Description of the Invention. The Summary of the Invention is not intended to limit the key features and essential features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0006] In order to at least partially solve the above problems, according to a first aspect of the present invention, a heat exchanger is provided, which includes a heat exchange pipeline, a heat conduction pipeline and a heat exchange pipeline. The heat exchange pipeline and the heat conduction pipeline both exchange heat with the heat exchange pipeline, and the heat exchange pipeline also exchanges heat with the heat conduction pipeline.

[0007] Exemplarily, the heat exchange pipeline includes a first pipeline and a second pipeline;

[0008] The heat transfer pipeline includes a third pipeline and a fourth pipeline;

[0009] The first pipeline and the third pipeline exchange heat with the heat exchange pipeline respectively;

[0010] The second pipeline exchanges heat with the fourth pipeline.

[0011] Exemplarily, the heat exchanger further includes a fifth pipeline, a first end of the fifth pipeline is connected to one end of the first pipeline, and a second end of the fifth pipeline is connected to one end of the second pipeline.

[0012] According to a second aspect of the present invention, there is provided a cascade heat pump system comprising:

[0013] a heat exchanger as described above;

[0014] a first heat pump unit, the first heat pump unit being in communication with the heat exchange pipeline;

[0015] a second heat pump unit, the second heat pump unit being in communication with the heat transfer pipeline;

[0016] The first heat pump unit is used to exchange heat between the heat exchange pipeline and the heat conduction pipeline through the heat exchange pipeline, and the second heat pump unit is used to exchange heat between the heat exchange pipeline and the heat conduction pipeline through the heat conduction pipeline.

[0017] Exemplarily, the first heat pump unit is used to heat or cool the heat exchange pipeline and the heat transfer pipeline through the heat exchange pipeline;

[0018] The second heat pump unit is used to heat and / or cool the heat exchange pipeline through the heat conduction pipeline.

[0019] Exemplarily, the cascade heat pump system includes a first heat exchange mode;

[0020] When the cascade heat pump system is in the first heat exchange mode, the first heat pump unit and the second heat pump unit operate simultaneously;

[0021] The first heat pump unit, the first pipe of the heat exchanger, and the second pipe of the heat exchanger together form a first refrigerant circulation loop, the first pipe exchanges heat with the heat exchange pipe, and the second pipe exchanges heat with the fourth pipe of the heat exchanger;

[0022] The second heat pump unit, the third pipeline of the heat exchanger, and the fourth pipeline together form a second refrigerant circulation loop, and the third pipeline exchanges heat with the heat exchange pipeline.

[0023] Exemplarily, the cascade heat pump system includes a second heat exchange mode;

[0024] When the cascade heat pump system is in the second heat exchange mode, the first heat pump unit does not work and the second heat pump unit works;

[0025] The second heat pump unit and the third pipeline together form a third refrigerant circulation loop, and the third pipeline exchanges heat with the heat exchange pipeline.

[0026] Exemplarily, the first heat pump unit comprises:

[0027] a first compressor, wherein the outlet of the first compressor is in communication with the inlet of the first pipeline, and the outlet of the first pipeline is in communication with the inlet of the second pipeline;

[0028] a gas-liquid separation and liquid storage device, comprising a first chamber and a second chamber, wherein the first chamber exchanges heat with the second chamber, the outlet of the first chamber is connected to the inlet of the first compressor, and the inlet of the second chamber is connected to the outlet of the second pipeline;

[0029] a first heat exchanger, wherein an outlet of the first heat exchanger is in communication with an inlet of the first chamber;

[0030] A first throttling device, wherein the inlet of the first throttling device is communicated with the outlet of the second chamber, and the outlet of the first throttling device is communicated with the inlet of the first heat exchanger.

[0031] Exemplarily, the second heat pump unit includes:

[0032] a second compressor, wherein an outlet of the second compressor is in communication with an inlet of the third pipeline;

[0033] a gas-liquid separation and liquid storage device, comprising a first chamber and a second chamber, wherein the first chamber exchanges heat with the second chamber, the outlet of the first chamber is connected to the inlet of the second compressor, and the inlet of the second chamber is connected to the outlet of the third pipeline;

[0034] a second throttling device, wherein the inlet of the second throttling device is communicated with the outlet of the second chamber, and the outlet of the second throttling device is communicated with the inlet of the fourth pipeline;

[0035] The outlet of the fourth pipeline is communicated with the inlet of the first chamber.

[0036] Exemplarily, the second heat pump unit includes:

[0037] A four-way reversing device, the four-way reversing device comprising a first interface, a second interface, a third interface and a fourth interface, wherein the first interface is connected to the first end of the third pipeline;

[0038] a second compressor, wherein an outlet of the second compressor is in communication with the second interface;

[0039] a gas-liquid separation and liquid storage device, comprising a first chamber and a second chamber, wherein the first chamber and the second chamber exchange heat, the inlet of the first chamber being connected to the third interface, and the outlet of the first chamber being connected to the inlet of the second compressor;

[0040] a second heat exchanger, wherein an inlet of the second heat exchanger is connected to the fourth interface;

[0041] a first one-way valve, wherein the inlet of the first one-way valve is in communication with the outlet of the second heat exchanger, and the outlet of the first one-way valve is in communication with the inlet of the second chamber;

[0042] a second one-way valve, wherein the inlet of the second one-way valve is connected to the second end of the third pipeline, and the outlet of the second one-way valve is connected to the inlet of the second chamber;

[0043] a second throttling device, wherein the inlet of the second throttling device is communicated with the outlet of the second chamber, the outlet of the second throttling device is communicated with the inlet of the fourth pipeline, and the outlet of the fourth pipeline is communicated with the fourth interface;

[0044] A third throttling device, wherein the inlet of the third throttling device is communicated with the outlet of the second chamber, and the outlet of the third throttling device is communicated with the second end of the third pipeline.

[0045] Exemplarily, the gas-liquid separation and liquid storage device includes a shell and a partition, the shell has a accommodating cavity therein, and the partition is arranged in the accommodating cavity and divides the accommodating cavity into the first chamber and the second chamber.

[0046] Exemplarily, the gas-liquid separation and liquid storage device includes an outer shell and an inner shell, the inner shell is arranged in the outer shell, the first chamber is formed between the outer shell and the inner shell, and the second chamber is provided in the inner shell.

[0047] Exemplarily, the first heat pump unit and the heat exchange pipeline contain a first refrigerant, the second heat pump unit and the heat transfer pipeline contain a second refrigerant, and the first refrigerant or the second refrigerant is carbon dioxide refrigerant.

[0048] According to the heat exchanger and cascade heat pump system of the present invention, the heat exchange pipes and heat transfer pipes in the heat exchanger both exchange heat with the heat exchange pipes, thereby allowing the heat exchange pipes to pass through the material to be exchanged, and the heat exchange pipes and heat transfer pipes to pass through the same or different refrigerants. Thus, the heat exchange pipes and heat transfer pipes can simultaneously heat or cool the material to be exchanged in the heat exchange pipes, or the heat exchange pipes and heat transfer pipes can heat or cool the material to be exchanged in the heat exchange pipes separately. The heat exchange pipes also exchange heat with the heat transfer pipes, thereby allowing the heat exchange pipes to heat or cool the refrigerant in the heat transfer pipes, thereby improving the heating effect or cooling effect of the refrigerant on the material to be exchanged in the heat exchange pipes. According to the heat exchanger and cascade heat pump system of the present invention, the heat exchange methods are diverse, and the heating effect or cooling effect on the material to be exchanged can be significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The following drawings of this application are hereby incorporated as part of this application for understanding this application. The drawings show the embodiments of this application and their descriptions, and are used to explain the device and principle of this application. In the drawings,

[0050] FIG1 is a schematic structural diagram of a cascade heat pump system according to an embodiment of the present application;

[0051] FIG2 is a schematic diagram of the pipelines in the heat exchanger in FIG1 ;

[0052] FIG3 is a schematic diagram of the flow directions of the first refrigerant, the second refrigerant, and the substance to be heat exchanged in the heat exchanger in FIG1 ;

[0053] FIG4 is a schematic structural diagram of a first gas-liquid separation and liquid storage device according to an embodiment of the present application;

[0054] FIG5 is a schematic structural diagram of a first gas-liquid separation and liquid storage device according to another embodiment of the present application;

[0055] FIG6 shows the flow directions of the first refrigerant and the second refrigerant when the cascade heat pump system in FIG1 is in the first heat exchange mode;

[0056] FIG7 shows the flow direction of the second refrigerant when the cascade heat pump system in FIG1 is in the second heat exchange mode.

[0057] Explanation of reference numerals: 100 - first heat pump unit, 200 - second heat pump unit; 1 - first compressor, 2 - gas-liquid separation and liquid storage device, 201 - outer shell, 202 - partition, 203 - inner shell, 21 - first chamber, 211 - inlet of the first chamber, 212 - outlet of the first chamber, 22 - second chamber, 221 - The inlet of the second chamber, 222-the outlet of the second chamber, 3-the first heat exchanger, 4-the first fan, 5-the first throttling device, 6-the heat exchanger, 61-the heat exchange pipeline, 611-the first pipeline, 612-the second pipeline, 613-the fifth pipeline, 62-the heat transfer pipeline, 621-the third pipeline, 622-the fourth pipeline, 63-the heat exchange pipeline, 601-the inlet of the heat exchange pipeline, 602-the outlet of the heat exchange pipeline, 603-the first end of the third pipeline, 604-the second end of the third pipeline, 60 5-inlet of the fourth pipeline, 606-outlet of the fourth pipeline, 607-inlet of the heat exchange pipeline, 608-outlet of the heat exchange pipeline, 7-second throttling device, 8-second heat exchanger, 9-second fan, 10-inlet of the heat exchange pipeline, 11-outlet of the heat exchange pipeline, 12-third throttling device, 13-second one-way valve, 14-first one-way valve, 15-four-way reversing device, 16-second compressor, 17-gas-liquid separation and liquid storage device, 171-first chamber, 172-second chamber. DETAILED DESCRIPTION

[0058] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present application. However, it will be apparent to those skilled in the art that the present application can be implemented without one or more of these details. In other examples, some technical features well known in the art are not described in order to avoid confusion with the present application.

[0059] It should be understood that the present application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the present application to those skilled in the art. In the drawings, the dimensions and relative sizes of layers and regions may be exaggerated for clarity. Like reference numerals throughout represent like elements.

[0060] It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or part from another element, component, region, layer, or part. Therefore, without departing from the teachings of this application, the first element, component, region, layer, or part discussed below may be represented as a second element, component, region, layer, or part.

[0061] Spatially relative terms, such as "below," "beneath," "beneath," "above," "upper," etc., may be used herein for convenience to describe the relationship of one element or feature to other elements or features illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and operation in addition to the orientations depicted in the figures.

[0062] The terminology used herein is intended only to describe specific embodiments and is not intended to limit the present application. When used herein, the singular forms "a," "an," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "including," when used in this specification, identify the presence of the described features, integers, steps, operations, elements, and / or parts, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0063] Embodiments of the invention are described herein with reference to cross-sectional views that are schematic diagrams of ideal embodiments (and intermediate structures) of the present application. Thus, variations in the shapes shown due to, for example, manufacturing techniques and / or tolerances can be expected. Therefore, the embodiments of the present application should not be limited to the specific shapes shown herein, but rather include shape deviations due to, for example, manufacturing. Therefore, what is shown in the figures is schematic in nature, and their shapes are not intended to show the actual shape of the device and are not intended to limit the scope of the present application.

[0064] 1 to 7 , a cascade heat pump system according to an embodiment of the present application is exemplarily described. The cascade heat pump system includes a heat exchanger 6 , a first heat pump unit 100 , and a second heat pump unit 200 .

[0065] Referring to FIG2 , the heat exchanger 6 includes a heat exchange pipeline 61, a heat conduction pipeline 62, and a heat exchange pipeline 63. The heat exchange pipeline 61 and the heat conduction pipeline 62 both exchange heat with the heat exchange pipeline 63, and the heat exchange pipeline 61 also exchanges heat with the heat conduction pipeline 62. It should be noted that the pipe-to-pipe heat exchange described in this application refers to the heat exchange between substances in the pipelines. The heat exchange pipeline 61 and the heat conduction pipeline 62 are respectively used to allow the same or different refrigerants to pass through, and the refrigerant can be, for example, a carbon dioxide refrigerant, a Freon refrigerant, etc. The heat exchange pipeline 63 is used to allow the substance to be exchanged to pass through, and the substance to be exchanged is a substance that needs to be heated or cooled, which can be water or other media. Thus, on the one hand, the heat exchange pipe 61 and the heat transfer pipe 62 can simultaneously heat or cool the heat exchange medium in the heat exchange pipe 63, or the heat exchange pipe 61 and the heat transfer pipe 62 can heat and cool the heat exchange medium in the heat exchange pipe 63 separately. On the other hand, the heat exchange pipe 61 can be used to heat or cool the refrigerant in the heat transfer pipe 62, thereby improving the heating effect or cooling effect of the refrigerant in the heat transfer pipe 62 on the heat exchange medium in the heat exchange pipe 63. The heat exchanger has a variety of heat exchange modes, which can significantly improve the heating effect or cooling effect on the heat exchange medium.

[0066] In this embodiment, the heat exchange pipeline 61 includes a first pipeline 611 and a second pipeline 612, and the heat transfer pipeline 62 includes a third pipeline 621 and a fourth pipeline 622. The first pipeline 611 and the third pipeline 621 respectively exchange heat with the heat exchange pipeline 63. The first pipeline 611 and the third pipeline 621 can be located on either side of the heat exchange pipeline 63, respectively. The second pipeline 612 exchanges heat with the fourth pipeline 622. The heat exchanger 6 also includes a fifth pipeline 613. The first end of the fifth pipeline 613 is connected to one end of the first pipeline 611, and the second end of the fifth pipeline 613 is connected to one end of the second pipeline 612. In other words, the first pipeline 611 and the second pipeline 612 are connected through the fifth pipeline 613 within the heat exchanger 6. After exchanging heat with the heat exchange pipeline 63 in the first pipeline 611, the refrigerant can enter the second pipeline 612 through the fifth pipeline 613 and then exchange heat with the fourth pipeline 622. In some other embodiments, the fifth pipeline 613 may not be provided in the heat exchanger 6, but may be provided outside the heat exchanger 6, and the first pipeline 611 and the second pipeline 612 are connected through the fifth pipeline 613 outside the heat exchanger 6. It should be noted that Figure 2 is only used to illustrate the relative position relationship of the pipelines in the heat exchanger 6. It does not represent the actual shape of the pipeline. The "pipeline" described in this application refers to the flow channel of the refrigerant or the substance to be heat exchanged, which may be tubular or in other shapes. The heat exchanger 6 may be a shell and tube heat exchanger, a plate heat exchanger or a heat exchanger of other structural forms.

[0067] The first heat pump unit 100 is in communication with the heat exchange pipeline 61, and the second heat pump unit 200 is in communication with the heat transfer pipeline 62. The first heat pump unit 100 is configured to exchange heat between the heat exchange pipeline 63 and the heat transfer pipeline 62 via the heat exchange pipeline 61, while the second heat pump unit 200 is configured to exchange heat between the heat exchange pipeline 63 and the heat transfer pipeline 62. A first refrigerant is provided in the first heat pump unit 100 and the heat exchange pipeline 61, while a second refrigerant is provided in the second heat pump unit 200 and the heat transfer pipeline 62.

[0068] Specifically, referring to FIG1 , the first heat pump unit 100 includes a first compressor 1, a first gas-liquid separation and liquid storage device 2, a first heat exchanger 3, a first throttling device 5, and a first fan 4. The first gas-liquid separation and liquid storage device 2 includes a first chamber 21 and a second chamber 22. The outlet of the first compressor 1 is connected to the inlet 601 of the heat exchange pipeline 61 (i.e., the inlet 601 of the first pipeline 611). The outlet 212 of the first chamber 21 is connected to the inlet of the first compressor 1. The first chamber 21 is used to separate the gas and liquid of the carbon dioxide refrigerant entering the first compressor 1, preventing liquid refrigerant from entering the first compressor 1 and thereby increasing the service life of the first compressor 1. Components related to gas-liquid separation may be provided within the first chamber 21. The inlet 221 of the second chamber 22 is connected to the outlet 602 of the heat exchange pipeline 61 (i.e., the outlet 602 of the second pipeline 612). The second chamber 22 is used for liquid storage, that is, for storing the liquid first refrigerant from the heat exchange pipeline 61. The first chamber 21 exchanges heat with the second chamber 22, that is, the first refrigerant in the first chamber 21 exchanges heat with the first refrigerant in the second chamber 22. The first heat exchanger 3 can be an evaporator or other heat exchanger for exchanging heat with air (or other heat exchange medium), and the outlet of the first heat exchanger 3 is connected to the inlet 211 of the first chamber 21. The first throttling device 5 can be a throttling device such as a capillary tube, a thermal expansion valve, or an electronic expansion valve. The inlet of the first throttling device 5 is connected to the outlet 222 of the second chamber 22, and the outlet of the first throttling device 5 is connected to the inlet of the first heat exchanger 3. The first fan 4 is adjacent to the first heat exchanger 3 and is used to provide heat exchange air volume for the first heat exchanger 3. In some embodiments, the first fan 4 may not be provided, and the first heat exchanger 3 naturally exchanges heat with the air.

[0069] Referring to FIG. 1 , in this embodiment, the second heat pump unit 200 includes a four-way reversing device 15, a second compressor 16, a second gas-liquid separation and liquid storage device 17, a second heat exchanger 8, a first one-way valve 14, a second one-way valve 13, a second throttling device 7, a third throttling device 12, and a second blower 9. The second gas-liquid separation and liquid storage device 17 includes a first chamber 171 and a second chamber 172. The four-way reversing device 15 includes a first port (the port on the right side of the four-way reversing device 15 in FIG. 1 ), a second port (the port on the bottom side of the four-way reversing device 15 in FIG. 1 ), a third port (the port on the top side of the four-way reversing device 15 in FIG. 1 ), and a fourth port (the port on the left side of the four-way reversing device 15 in FIG. The first port is connected to the first end 603 of the third pipeline 621. The outlet of the second compressor 16 is connected to the second port. The inlet of the first chamber 171 is connected to the third interface, and the outlet of the first chamber 171 is connected to the inlet of the second compressor 16. The first chamber 171 is used to separate the gas and liquid of the second refrigerant entering the second compressor 16, preventing liquid refrigerant from entering the second compressor 16 and increasing the service life of the second compressor 16. The first chamber 171 may be provided with components for gas-liquid separation. The second heat exchanger 8 may be a condenser or other heat exchanger for exchanging heat with air (or other heat exchange medium). The inlet of the second heat exchanger 8 is connected to the fourth interface. The inlet of the first one-way valve 14 is connected to the outlet of the second heat exchanger 8. The outlet of the first one-way valve 14 is connected to the inlet of the second chamber 172. The second chamber 172 is used for storing liquid, that is, for storing the liquid second refrigerant. The first chamber 171 and the second chamber 172 exchange heat, that is, the second refrigerant in the first chamber 171 exchanges heat with the second refrigerant in the second chamber 172. The inlet of the second one-way valve 13 is connected to the second end 604 of the third pipeline 621, and the outlet of the second one-way valve 13 is connected to the inlet of the second chamber 172. The second throttling device 7 can be a throttling device such as a thermal expansion valve or an electronic expansion valve. The inlet of the second throttling device 7 is connected to the outlet of the second chamber 172, the outlet of the second throttling device 7 is connected to the inlet 605 of the fourth pipeline 622, and the outlet 606 of the fourth pipeline 622 is connected to the fourth interface. The third throttling device 12 can be a throttling device such as a thermal expansion valve or an electronic expansion valve. The inlet of the third throttling device 12 is connected to the outlet of the second chamber 172, and the outlet of the third throttling device 12 is connected to the second end 604 of the third pipeline 621. The second fan 9 is arranged adjacent to the second heat exchanger 8 to provide heat exchange air volume for the second heat exchanger 8. In some embodiments, the second fan 9 may not be provided, and the second heat exchanger 8 naturally exchanges heat with the air.

[0070] The cascade heat pump system of this embodiment includes a first heat exchange mode. When the cascade heat pump system is in the first heat exchange mode, the first heat pump unit 100 and the second heat pump unit 200 work simultaneously. The first heat pump unit 100, the first pipeline 611 and the second pipeline 612 (the first pipeline 611 and the second pipeline 612 are connected through the fifth pipeline 613) together form a first refrigerant circulation loop. The first pipeline 611 exchanges heat with the heat exchange pipeline 613, and the second pipeline 612 exchanges heat with the fourth pipeline 622; the second heat pump unit 200, the third pipeline 621 and the fourth pipeline 622 together form a second refrigerant circulation loop, and the third pipeline 621 exchanges heat with the heat exchange pipeline 63.

[0071] Specifically, referring to FIG6 , when the cascade heat pump system is in the first heat exchange mode, the first compressor 1 and the second compressor 16 are started, the first throttling device 5 and the second throttling device 7 are in operation, the third throttling device 12 is inoperative, and the four-way reversing device 15 has its first and second interfaces connected, and its third and fourth interfaces connected. The flow direction of the first refrigerant is as follows: first compressor 1 → heat exchange pipeline 61 in heat exchanger 6 (i.e., first pipeline 611 → fifth pipeline 613 → second pipeline 612) → second chamber 22 → first throttling device 5 → first heat exchanger 3 → first chamber 21 → first compressor 1. The flow direction of the second refrigerant is as follows: second compressor 16 → four-way reversing device 15 → third pipeline 621 in heat exchanger 6 → second one-way valve 13 → second chamber 172 → second throttling device 7 → fourth pipeline 622 in heat exchanger 6 → four-way reversing device 15 → first chamber 171 → second compressor 16. The first refrigerant absorbs heat from the environment through the first heat exchanger 3 and releases the absorbed heat into the heat exchanger 6 through the heat exchange pipe 61. Referring to Figure 3, after the high-temperature first refrigerant from the first compressor 1 enters the heat exchange pipe 61 in the heat exchanger 6 through the inlet 601 of the first pipe 611, it first exchanges heat with the heat exchange material in the heat exchange pipe 63 to heat the heat exchange material and increase the temperature of the heat exchange material. It then exchanges heat with the second refrigerant in the fourth pipe 622, transferring the remaining heat to the second refrigerant. The high-temperature second refrigerant from the second compressor 16 enters the third pipe 621 in the heat exchanger 6 to exchange heat with the heat exchange material in the heat exchange pipe 63 to heat the heat exchange material. After heat exchange, the low-temperature second refrigerant will enter the fourth pipeline 622 for heat exchange and temperature increase with the first refrigerant in the heat exchange pipeline 61 after throttling, and then enter the second compressor 16 for compression after temperature increase. Thus, the temperature of the compressed second refrigerant can be significantly increased, thereby improving the heating capacity of the second heat pump unit 200.

[0072] The cascade heat pump system of this embodiment also includes a second heat exchange mode. When the cascade heat pump system is in the second heat exchange mode, the first heat pump unit 100 is inoperative, while the second heat pump unit 200 is inoperative. The second heat pump unit 200 and the third pipeline 621 together form a third refrigerant circulation loop, and the third pipeline 621 exchanges heat with the heat exchange pipeline 63.

[0073] Specifically, referring to FIG7 , when the cascade heat pump system is in the second heat exchange mode, the first heat pump unit 100 is inoperative, the first compressor 1 is inoperative, the second compressor 16 is inoperative, the first throttling device 5 and the second throttling device 7 are inoperative, the third throttling device 12 is inoperative, and the four-way reversing device 15 is electrically connected between its first and fourth interfaces, and between its second and third interfaces. The second refrigerant flows as follows: second compressor 16 → four-way reversing device 15 → second heat exchanger 8 → first one-way valve 14 → second chamber 172 → third throttling device 12 → third pipeline 621 in heat exchanger 6 → four-way reversing device 15 → first chamber 171 → second compressor 16. The second refrigerant exchanges heat with the heat exchange medium in heat exchanger 6, absorbing the heat of the heat exchange medium, cooling the heat exchange medium and lowering its temperature. The absorbed heat is then released to the outside environment through the second heat exchanger 8.

[0074] In this embodiment, the first refrigerant is carbon dioxide, which can be solely carbon dioxide or a mixture of carbon dioxide and other refrigerants. Due to its unique physical properties, carbon dioxide has a low evaporation temperature and is effective at extracting heat at low temperatures, particularly when the outdoor ambient temperature is low. The second refrigerant is a Freon refrigerant, which can include R134A, R741A, R290, and others. Freon refrigerants offer excellent cooling performance.

[0075] When the heat exchange material requires heating, a first heat exchange mode can be used, where the first heat pump unit 100 and the second heat pump unit 200 are used to heat the heat exchange material simultaneously. When the heat exchange material requires cooling, a second heat exchange mode can be used, where the second heat pump unit 200 is used alone to cool the heat exchange material. This allows for the combined use of the good heating performance of the first heat pump unit 100 and the good cooling performance of the second heat pump unit 200, enabling the cascade heat pump system to simultaneously achieve both good cooling and heating performance. Furthermore, when the first heat pump unit 100 and the second heat pump unit 200 are simultaneously heating the heat exchange material, the carbon dioxide refrigerant in the heat exchange line 61, after exchanging heat with the heat exchange material in the heat exchange line 63, also exchanges heat with the Freon refrigerant in the fourth line 622. This increases the temperature (e.g., evaporation temperature) of the Freon refrigerant in the second heat pump unit 200, thereby improving the heating capacity of the second heat pump unit 200 and further enhancing the heating performance of the heat exchange material.

[0076] According to the cascade heat pump system of the present application, the heating process is that the carbon dioxide refrigerant and the Freon refrigerant condense simultaneously to provide heat to the heat exchange material, and the heating efficiency and capacity are high. The heating process uses the condensation heat of the carbon dioxide refrigerant in two stages, the high-temperature stage to provide heat to the heat exchange material, and the low-temperature stage to provide heat to the Freon refrigerant, thereby increasing the Freon evaporation temperature, thereby increasing the condensation temperature, and increasing the Freon refrigerant's heating capacity for the heat exchange material. The cooling process only utilizes the second heat pump unit 200, and the cooling capacity and efficiency for the heat exchange material are high. The switching between cooling and heating is achieved by a four-way reversing valve, a throttling device, and a one-way valve, with high conversion efficiency and high system reliability.

[0077] Referring to Figure 4, in this embodiment, the first gas-liquid separation and liquid storage device 2 includes a shell 201 and a partition 202. The shell 201 has a accommodating chamber. The partition 202 is arranged in the accommodating chamber and divides the accommodating chamber into a first chamber 21 and a second chamber 22. That is, the first chamber 21 and the second chamber 22 are arranged side by side and separated by the partition 202. The first refrigerant in the first chamber 21 and the first refrigerant in the second chamber 22 are heat exchanged through the partition 202, thereby increasing the temperature of the first refrigerant entering the first compressor 1 and improving the service life of the first compressor 1.

[0078] Referring to FIG. 5 , in some embodiments, the first gas-liquid separation and liquid storage device 2 may include an outer shell 201 and an inner shell 203. The inner shell 203 is disposed in the outer shell 201. A first chamber 21 is formed between the outer shell 201 and the inner shell 203. The inner shell 203 includes a second chamber 22. That is, the second chamber 22 is disposed within the first chamber 21, and the first chamber 21 is sleeved outside the second chamber 22. The first refrigerant in the first chamber 21 exchanges heat with the first refrigerant in the second chamber 22 through the inner shell 203, thereby increasing the temperature of the first refrigerant entering the first compressor 1 and improving the service life of the first compressor 1.

[0079] The specific structure of the second gas-liquid separation and liquid storage device 17 is the same as that of the first gas-liquid separation and liquid storage device 2 and will not be repeated here. The second refrigerant in the first chamber 171 exchanges heat with the second refrigerant in the second chamber 172, thereby increasing the temperature of the second refrigerant entering the second compressor 16 and improving the service life of the second compressor 16.

[0080] In some other embodiments, the second refrigerant may also be carbon dioxide refrigerant.

[0081] In this embodiment, the first heat pump unit 100 is used to heat the heat exchange pipe 63 and the heat transfer pipe 62 through the heat exchange pipe 61. In other embodiments, the first heat pump unit 100 may be a heat pump unit of other structural forms, and the first heat pump unit 100 may be used to cool the heat exchange pipe 63 and the heat transfer pipe 62 through the heat exchange pipe 61.

[0082] In this embodiment, the second heat pump unit 200 can be used to heat or cool the heat exchange pipe 63 via the heat transfer pipe 62. In other embodiments, the second heat pump unit 200 can be a heat pump unit of other structural forms, and the second heat pump unit 200 can be used to heat or cool the heat exchange pipe 63 via the heat transfer pipe 62. For example, in some embodiments, the second heat pump unit 200 may only include the second compressor 16, the second gas-liquid separation and liquid storage device 17, and the second throttling device 7. The outlet of the second compressor 16 is connected to the inlet of the third pipe 621. The outlet of the first chamber 171 is connected to the inlet of the second compressor 16, and the inlet of the second chamber 172 is connected to the outlet of the third pipe 621. The inlet of the second throttling device 7 is connected to the outlet of the second chamber 172, and the outlet of the second throttling device 7 is connected to the inlet 605 of the fourth pipe 622. The outlet 606 of the fourth pipe 622 is connected to the inlet of the first chamber 171. When the second compressor 16 and the second throttling device 7 are working, the flow direction of the second refrigerant is as follows: second compressor 16 → third pipe 621 in the heat exchanger 6 → second chamber 172 → second throttling device 7 → fourth pipe 622 in the heat exchanger 6 → first chamber 171 → second compressor 16. The high-temperature second refrigerant from the second compressor 16 enters the third pipe 621 in the heat exchanger 6 to exchange heat with the heat exchange material in the heat exchange pipe 63, thereby heating the heat exchange material. After heat exchange, the low-temperature second refrigerant, after throttling and cooling, enters the fourth pipe 622 to exchange heat with the first refrigerant in the heat exchange pipe 61 to increase its temperature. After heating, it enters the second compressor 16 for compression. Thus, the temperature of the compressed second refrigerant can be significantly increased, thereby improving the heating capacity of the second heat pump unit 200.

[0083] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely illustrative and are not intended to limit the scope of the present application. Various changes and modifications may be made therein by those skilled in the art without departing from the scope and spirit of the present application. All such changes and modifications are intended to be included within the scope of the present application as required by the appended claims.

[0084] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0085] Similarly, it should be understood that in order to streamline the present application and aid in understanding one or more of the various inventive aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, this approach of the present application should not be interpreted as reflecting the intention that the application claimed for protection requires more features than those explicitly recited in each claim. More precisely, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with fewer features than all the features of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into the detailed description, with each claim itself serving as a separate embodiment of the present application.

[0086] Those skilled in the art will understand that, except where mutually exclusive, all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or apparatus disclosed herein may be combined in any combination. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that provides the same, equivalent, or similar purpose.

[0087] Furthermore, those skilled in the art will appreciate that although some embodiments described herein include certain features included in other embodiments but not other features, combinations of features from different embodiments are intended to be within the scope of this application and to form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.

[0088] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims.

Claims

1. A heat exchanger, characterized in that: The heat exchanger includes a heat exchange pipeline, a heat conduction pipeline and a heat exchange pipeline. The heat exchange pipeline and the heat conduction pipeline both exchange heat with the heat exchange pipeline, and the heat exchange pipeline also exchanges heat with the heat conduction pipeline.

2. The heat exchanger according to claim 1, characterized in that The heat exchange pipeline includes a first pipeline and a second pipeline; The heat transfer pipeline includes a third pipeline and a fourth pipeline; The first pipeline and the third pipeline exchange heat with the heat exchange pipeline respectively; The second pipeline exchanges heat with the fourth pipeline.

3. The heat exchanger according to claim 2, characterized in that The heat exchanger further includes a fifth pipeline, a first end of the fifth pipeline is connected to one end of the first pipeline, and a second end of the fifth pipeline is connected to one end of the second pipeline.

4. A cascade heat pump system, characterized in that: include: The heat exchanger according to any one of claims 1 to 3; a first heat pump unit, the first heat pump unit being in communication with the heat exchange pipeline; a second heat pump unit, the second heat pump unit being in communication with the heat transfer pipeline; The first heat pump unit is used to exchange heat between the heat exchange pipeline and the heat conduction pipeline through the heat exchange pipeline, and the second heat pump unit is used to exchange heat between the heat exchange pipeline and the heat conduction pipeline through the heat conduction pipeline.

5. The cascade heat pump system according to claim 4, characterized in that: The first heat pump unit is used to heat or cool the heat exchange pipeline and the heat conduction pipeline through the heat exchange pipeline; The second heat pump unit is used to heat and / or cool the heat exchange pipeline through the heat conduction pipeline.

6. The cascade heat pump system according to claim 4, characterized in that: The cascade heat pump system includes a first heat exchange mode; When the cascade heat pump system is in the first heat exchange mode, the first heat pump unit and the second heat pump unit operate simultaneously; The first heat pump unit, the first pipe of the heat exchanger and the second pipe of the heat exchanger together form a first refrigerant circulation loop. The first pipe exchanges heat with the heat exchange pipe. The second pipeline exchanges heat with the fourth pipeline of the heat exchanger; The second heat pump unit, the third pipeline of the heat exchanger, and the fourth pipeline together form a second refrigerant circulation loop, and the third pipeline exchanges heat with the heat exchange pipeline.

7. The cascade heat pump system according to claim 6, characterized in that: The cascade heat pump system includes a second heat exchange mode; When the cascade heat pump system is in the second heat exchange mode, the first heat pump unit does not work and the second heat pump unit works; The second heat pump unit and the third pipeline together form a third refrigerant circulation loop, and the third pipeline exchanges heat with the heat exchange pipeline.

8. The cascade heat pump system according to claim 6, characterized in that: The first heat pump unit comprises: a first compressor, wherein the outlet of the first compressor is in communication with the inlet of the first pipeline, and the outlet of the first pipeline is in communication with the inlet of the second pipeline; a gas-liquid separation and liquid storage device, comprising a first chamber and a second chamber, wherein the first chamber exchanges heat with the second chamber, the outlet of the first chamber is connected to the inlet of the first compressor, and the inlet of the second chamber is connected to the outlet of the second pipeline; a first heat exchanger, wherein an outlet of the first heat exchanger is in communication with an inlet of the first chamber; A first throttling device, wherein the inlet of the first throttling device is communicated with the outlet of the second chamber, and the outlet of the first throttling device is communicated with the inlet of the first heat exchanger.

9. The cascade heat pump system according to claim 6, characterized in that: The second heat pump unit comprises: a second compressor, wherein an outlet of the second compressor is in communication with an inlet of the third pipeline; a gas-liquid separation and liquid storage device, comprising a first chamber and a second chamber, wherein the first chamber exchanges heat with the second chamber, the outlet of the first chamber is connected to the inlet of the second compressor, and the inlet of the second chamber is connected to the outlet of the third pipeline; a second throttling device, wherein the inlet of the second throttling device is communicated with the outlet of the second chamber, and the outlet of the second throttling device is communicated with the inlet of the fourth pipeline; The outlet of the fourth pipeline is communicated with the inlet of the first chamber.

10. The cascade heat pump system according to claim 6, characterized in that: The second heat pump unit comprises: A four-way reversing device includes a first interface, a second interface, and a third interface. and a fourth interface, wherein the first interface is in communication with the first end of the third pipeline; a second compressor, wherein an outlet of the second compressor is in communication with the second interface; a gas-liquid separation and liquid storage device, comprising a first chamber and a second chamber, wherein the first chamber and the second chamber exchange heat, the inlet of the first chamber being connected to the third interface, and the outlet of the first chamber being connected to the inlet of the second compressor; a second heat exchanger, wherein an inlet of the second heat exchanger is connected to the fourth interface; a first one-way valve, wherein the inlet of the first one-way valve is in communication with the outlet of the second heat exchanger, and the outlet of the first one-way valve is in communication with the inlet of the second chamber; a second one-way valve, wherein the inlet of the second one-way valve is connected to the second end of the third pipeline, and the outlet of the second one-way valve is connected to the inlet of the second chamber; a second throttling device, wherein the inlet of the second throttling device is communicated with the outlet of the second chamber, the outlet of the second throttling device is communicated with the inlet of the fourth pipeline, and the outlet of the fourth pipeline is communicated with the fourth interface; A third throttling device, wherein the inlet of the third throttling device is communicated with the outlet of the second chamber, and the outlet of the third throttling device is communicated with the second end of the third pipeline.

11. The cascade heat pump system according to any one of claims 8 to 10, characterized in that: The gas-liquid separation and liquid storage device includes a shell and a partition. The shell has a receiving cavity therein. The partition is arranged in the receiving cavity and divides the receiving cavity into the first chamber and the second chamber.

12. The cascade heat pump system according to any one of claims 8 to 10, characterized in that: The gas-liquid separation and liquid storage device includes an outer shell and an inner shell. The inner shell is arranged in the outer shell. The first chamber is formed between the outer shell and the inner shell. The second chamber is provided in the inner shell.

13. The cascade heat pump system according to any one of claims 4 to 10, characterized in that: The first heat pump unit and the heat exchange pipeline contain a first refrigerant, the second heat pump unit and the heat transfer pipeline contain a second refrigerant, and the first refrigerant or the second refrigerant is carbon dioxide refrigerant.

Images