Double-pipe heat exchanger, heat exchanger unit and heat pump unit

Abstract

The utility model provides a double-pipe heat exchanger, a heat exchanger unit and a heat pump unit, relates to the technical field of heat pumps, and solves the problem of low energy efficiency of the heat pump unit caused by insufficient heat exchange of a double-pipe heat exchanger in the related technology. Therefore, sufficient heat exchange can be achieved corresponding to different operation modes, the heat exchange area is effectively utilized, heat exchange of the heat pump unit is more sufficient, and the energy efficiency of the unit is effectively improved.

Description

Technical Field

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

[0002] There are two devices as heat exchangers in the traditional heat pump unit, namely the fin heat exchanger and the shell and tube heat exchanger, which play an important role in the system whether it is a condenser or an evaporator. The traditional shell and tube heat exchanger is in the form of a fluorine-wrapped tube, that is, the refrigerant wraps the water copper tube for heat exchange, and its gas pipe is usually located at the upper end. Furthermore, for the gaseous refrigerant, it is in a state of high temperature and high pressure when entering the shell and tube heat exchanger, and the hot gas rises, which easily leads to partial closure of some copper tubes. Moreover, for the traditional shell and tube heat exchanger, its liquid pipe is directly connected to the bottom of the shell and tube heat exchanger, and there is no excessive supercooling part reserved. Therefore, the shell and tube heat exchanger in the related art lacks the opportunity to exchange heat with the refrigerant, which is prone to insufficient heat exchange, resulting in low energy efficiency of the heat pump unit. Utility Model Content

[0003] The present application provides a shell and tube heat exchanger, a heat exchanger unit and a heat pump unit, which solves the problem in the related art that the shell and tube heat exchanger is prone to insufficient heat exchange, resulting in low energy efficiency of the heat pump unit. The present solution can effectively avoid the occurrence of insufficient heat exchange and maintain a high degree of subcooling to improve the energy efficiency of the unit.

[0004] In a first aspect, the present application provides a shell and tube heat exchanger, which includes a shell and tube body, a liquid pipe, a first gas pipe and a second gas pipe.

[0005] The sleeve body includes an outer tube and an inner tube which are coaxially arranged and have the same height. The outer tube is sleeved outside the inner tube, and a copper tube is coiled inside the outer tube. The copper tube is coiled around the outer wall of the inner tube in the outer tube to form a multi-layer spiral structure.

[0006] A first perforated tube and a second perforated tube are provided on the side wall of the casing body, and the first perforated tube and the second perforated tube are both used to connect the inner tube with the outside, wherein the first perforated tube is also used to release flash gas to the outside, and the second perforated tube is also used to feed liquid into the inner tube;

[0007] Part of the liquid pipe is located inside the inner tube to connect the inner tube with the outside, and the lower pipe opening of the liquid pipe is far away from the bottom of the inner tube. The lower pipe opening of the liquid pipe is the pipe opening of the part of the liquid pipe located in the inner tube.

[0008] The first air pipe is connected to the inner tube, and the first air pipe is located at the upper part of the casing body, and the upper part of the casing body corresponds to one side of the access liquid pipe;

[0009] The second air pipe is communicated with the inner tube, and the second air pipe is located at the lower part of the sleeve body, and the lower part of the sleeve body is the other side opposite to the upper part.

[0010] In a second aspect, the present application further provides a heat exchanger unit, which includes a first solenoid valve, a second solenoid valve, a third solenoid valve, a three-way valve, a flash evaporator, and the above-mentioned shell and tube heat exchanger;

[0011] The first gas pipe of the shell and tube heat exchanger is connected to the first solenoid valve, the second gas pipe of the shell and tube heat exchanger is connected to the second solenoid valve, the first solenoid valve and the second solenoid valve are also connected to the three-way valve, the first solenoid valve is used to open in the cooling mode, the second solenoid valve is used to open in the heating mode, and the three-way valve is also used to communicate with one end of the four-way valve;

[0012] The air inlet port of the flash evaporator is connected to the first perforated tube of the shell-and-tube heat exchanger through the third solenoid valve, and the air outlet port of the flash evaporator is used to be connected to the compressor.

[0013] In a third aspect, the present application also provides a heat pump unit, which includes the above-mentioned heat exchanger unit.

[0014] The shell and tube heat exchanger of the present application can be connected to the gaseous refrigerant through different gas pipes, so that sufficient heat exchange can be achieved corresponding to different operating modes, thereby effectively utilizing the heat exchange area, making the heat exchange of the heat pump unit more sufficient and effectively improving the energy efficiency of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic cross-sectional view of a shell and tube heat exchanger provided in one embodiment of the present application;

[0016] Figure 2 A schematic structural diagram of a heat exchanger unit provided in one embodiment of the present application.

[0017] Reference numerals:

[0018] The casing body 110 , the outer tube 111 , the inner tube 112 , the copper tube 113 , the liquid tube 120 , the first gas tube 130 , the second gas tube 140 , the first perforated tube 150 , the second perforated tube 160 , the first solenoid valve 210 , the second solenoid valve 220 , the third solenoid valve 230 , the three-way valve 240 , and the flash evaporator 250 . DETAILED DESCRIPTION

[0019] The embodiments of the present application are further described in detail below in conjunction with the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are only used to explain the embodiments of the present application, rather than to limit the embodiments of the present application. It should also be noted that, for ease of description, only the parts related to the embodiments of the present application rather than all structures are shown in the accompanying drawings, and those skilled in the art should be able to think of it after reading the specification of this application that as long as the technical features do not contradict each other, any combination of the technical features can constitute an optional implementation method.

[0020] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable when appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally a class, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally represents that the objects associated before and after are in an "or" relationship. In the description of the present application, "multiple" means two or more, and "several" means one or more.

[0021] In the heat pump unit, the fin heat exchanger and the shell and tube heat exchanger are both important heat exchangers in the unit. The fin heat exchanger and the shell and tube heat exchanger can play the role of evaporator or condenser. However, the traditional shell and tube heat exchanger adopts fluorine-wrapped tubes, that is, the refrigerant (such as fluoride) wraps the water copper tube for heat exchange. And its gas pipe is usually located at the upper end. For this reason, the gaseous refrigerant is in a high temperature and high pressure state when entering the shell and tube heat exchanger. The hot gas rises, so it is easy to have a partial closure inside the copper tube. In addition, the liquid pipe in the traditional shell and tube heat exchanger is directly connected to the bottom of the shell and tube heat exchanger, and there is no excessive supercooling part reserved on it. Therefore, the traditional shell and tube heat exchanger lacks the opportunity to exchange heat with the refrigerant, and it is easy to have insufficient heat exchange and cause the problem of low energy efficiency of the heat pump unit.

[0022] In this regard, the present application provides a shell and tube heat exchanger, which can be used in a heat pump unit. Figure 1 A cross-sectional schematic diagram of a shell and tube heat exchanger provided in one embodiment of the present application is shown in FIG. Figure 1 As shown, the shell and tube heat exchanger includes a shell and tube body 110 , a liquid pipe 120 , a first gas pipe 130 and a second gas pipe 140 .

[0023] The sleeve body 110 includes an outer cylinder 111 and an inner cylinder 112. The outer cylinder 111 and the inner cylinder 112 are coaxially arranged, and the heights of the two are equal. The outer cylinder 111 is sleeved on the inner cylinder 112, that is, the sizes of the two are different in width, so that the inner cylinder 112 can be arranged inside the outer cylinder 111 to divide and form two different chambers. It is conceivable that the outer cylinder 111 and the inner cylinder 112 included in the sleeve body 110 can also be arranged in a cube or a rectangular parallelepiped shape. Figure 1 The cylindrical outer cylinder 111 and the inner cylinder 112 are taken as an example for explanation.

[0024] A copper tube 113 is arranged in the chamber between the outer tube 111 and the inner tube 112. The copper tube 113 is wound on the outer wall of the inner tube 112 to form a multi-layer spiral structure, that is, the copper tube 113 is arranged in circles along the outer wall of the inner tube 112 to increase the contact area between the copper tube 113 and the inner tube 112. In addition, a first opening and a second opening are provided on the side wall of the sleeve body 110. Accordingly, a first opening tube 150 is provided to correspond to the first opening to connect the inner tube 112 and the outside of the sleeve body 110, so that the flash gas can be released to the outside of the sleeve body 110 through the first opening tube 150; and a second opening tube 160 is provided to correspond to the second opening to connect the inner tube 112 and the outside of the sleeve body 110, so that the liquid can be introduced into the inner tube 112 through the second opening tube 160.

[0025] The liquid pipe 120 can be used as a device for circulating liquid in the shell-and-tube heat exchanger, and part of the pipe is located inside the inner tube 112, so as to connect the inner tube 112 with the outside to guide the liquid out, such as to the four-way valve in the heat pump unit, so as to enter the circulation of the heat pump unit again. Moreover, the lower pipe opening of the liquid pipe 120 is located at the pipe opening of the inner tube 112, which is far away from the bottom of the inner tube 112, that is, the lower pipe opening of the liquid pipe 120 is far away from the bottom of the inner tube 112, so as to reserve the corresponding supercooling part.

[0026] The first air pipe 130 and the second air pipe 140 are both connected to the inner tube 112, so that in the corresponding operation mode, the corresponding air pipe is selected to inlet or outlet air into the inner tube 112. However, the first air pipe 130 and the second air pipe 140 are located at different positions, and the two are arranged oppositely. For example, the first air pipe 130 is located at the upper part of the sleeve body 110, that is, the side of the sleeve body 110 connected to the liquid pipe 120, and the second air pipe 140 is located at the lower part of the sleeve body 110.

[0027] It can be understood that the first air pipe 130 and the second air pipe 140 serve as air inlet channels corresponding to different operating modes, and the shell and tube heat exchanger can be connected to the gaseous refrigerant through different air pipes, so that sufficient heat exchange can be achieved corresponding to different operating modes, thereby effectively utilizing the heat exchange area, making the heat exchange of the heat pump unit more sufficient and effectively improving the energy efficiency of the unit.

[0028] In some embodiments, the first perforated tube is located at the upper part of the casing body, and the second perforated tube is located at the lower part of the casing body, that is, the first perforated tube and the second perforated tube are arranged opposite to each other, and the first perforated tube serves as a pipe for circulating flash gas, which is arranged at the upper part of the casing body to facilitate the discharge of gas; the second perforated tube serves as a pipe for introducing liquid into the inner tube, which is arranged at the lower part of the casing body, so that the introduced liquid can more fully exchange heat with the copper tube, so as to better improve the energy efficiency of the unit.

[0029] It should be noted that, in one embodiment, a plurality of first perforated tubes and second perforated tubes are provided on the side wall of the sleeve body, and the first perforated tubes and the second perforated tubes are the same in number, thereby increasing the air intake speed and further contributing to improving the energy efficiency of the heat pump unit.

[0030] In one embodiment, the distance from the opening position of the first perforated tube corresponding to the inner tube to the top of the inner tube is a first distance, and the first distance is less than or equal to 100 mm. The first perforated tube is used to connect the inner tube with the outside, and has a perforated position on the inner side wall of the inner tube, and the perforated position is spaced a first distance from the top of the inner tube, wherein the first distance is less than or equal to 100 mm, that is, the maximum distance between the opening position of the first perforated tube and the top of the inner tube is 100 mm, so as to prevent the gas from escaping.

[0031] In one embodiment, the diameter of the first perforated tube is greater than or equal to 5 mm and less than or equal to 7 mm, that is, the diameter of the first perforated tube is between 5 mm and 7 mm, and the specific diameter can be selected according to the exhaust volume in actual application to control the exhaust during operation. It should be noted that in some embodiments, the first perforated tube and the second perforated tube have the same diameter for easy processing.

[0032] In one embodiment, the distance from the corresponding opening position of the second perforated tube in the inner tube to the bottom of the inner tube is the second distance, and the second distance is less than or equal to 50 mm. It can be understood that the second perforated tube also has a corresponding opening position on the side wall of the inner tube, and the opening position is spaced from the bottom of the inner tube by the second distance, wherein the second distance is less than or equal to 50 mm, that is, the maximum distance between the opening position of the second perforated tube and the bottom of the inner tube is 50 mm, so that the liquid can fully exchange heat with the copper tube after entering.

[0033] In one embodiment, the diameter of the second perforated tube is greater than or equal to 5 mm and less than or equal to 7 mm. Similarly, the diameter of the second perforated tube is between 5 mm and 7 mm. The specific diameter can be selected according to the liquid inflow in actual application to control the liquid inflow during operation.

[0034] In one embodiment, the distance from the lower pipe opening of the liquid pipe to the bottom of the inner tube is a third distance, and the third distance is at most one-third of the height of the inner tube. It can be understood that the lower pipe opening of the liquid pipe has a corresponding height limit, and the height of the lower pipe opening of the liquid pipe (i.e., the third distance) is at most one-third of the height of the inner tube, so as to reserve a corresponding subcooling part for the shell-and-tube heat exchanger. Exemplarily, the height of the lower pipe opening of the liquid pipe from the bottom of the inner tube is one-third of the height of the inner tube, thereby reserving a corresponding subcooling part for the shell-and-tube heat exchanger, which helps to improve the subcooling degree of the heat pump unit, so that the unit can perform heat exchange more fully.

[0035] It should be noted that, in some embodiments, the height of the lower pipe opening of the liquid pipe from the bottom of the inner cylinder is one-fourth of the height of the inner cylinder, so that the liquid in the inner cylinder can be discharged more quickly, and the corresponding subcooling part can be reserved, which helps to improve the subcooling degree of the heat pump system, thereby facilitating sufficient heat exchange of the unit.

[0036] The present application also provides a heat exchanger unit, which plays a heat exchange role as a condenser or evaporator in a heat pump unit, such as Figure 2 As shown, Figure 2 This is a schematic diagram of the structure of a heat exchanger unit provided in one embodiment of the present application, wherein the heat exchanger unit includes a first solenoid valve 210, a second solenoid valve 220, a third solenoid valve 230, a three-way valve 240, a flash evaporator 250 and the shell and tube heat exchanger provided in the above embodiment.

[0037] The first air pipe 130 of the shell and tube heat exchanger is connected to the first electromagnetic valve 210, the second air pipe 140 of the shell and tube heat exchanger is connected to the second electromagnetic valve 220, the first electromagnetic valve 210 and the second electromagnetic valve 220 are also connected to the three-way valve 240, the first electromagnetic valve 210 is used to open in the cooling mode, the second electromagnetic valve 220 is used to open in the heating mode, and the three-way valve 240 is also used to communicate with one end of the four-way valve of the heat pump unit. The air inlet port of the flash evaporator 250 is connected to the first perforated pipe 150 of the shell and tube heat exchanger through the third electromagnetic valve 230, and the air outlet port of the flash evaporator 250 is used to communicate with the compressor. The flash evaporator 250 is used to reduce the flash gas in the shell and tube heat exchanger, thereby increasing the corresponding heat exchange area inside the shell and tube heat exchanger.

[0038] It can be understood that, in the cooling mode, the refrigerant in the gas-liquid two-phase state enters the inner tube 112 of the shell and tube heat exchanger from the liquid pipe 120, and accordingly, the first solenoid valve 210 is opened, the second solenoid valve 220 is closed, and the gas generated after the refrigerant completes the heat exchange (absorption) between the inner tube 112 and the copper tube 113 can escape through the first gas pipe 130. When flash gas appears during the heat exchange process, it can be led out through the first perforated pipe 150 on the shell and tube heat exchanger, that is, by controlling the third solenoid valve 230 to open, the flash gas is introduced into the flash evaporator 250, and the flash evaporator 250 works to reduce the flash gas in the shell and tube heat exchanger, thereby increasing the heat exchange area.

[0039] In addition, in the heating mode, the second solenoid valve 220 is opened and the first solenoid valve 210 is closed, so that the high-temperature and high-pressure gaseous refrigerant enters the inner tube 112 from the lower part of the shell and tube heat exchanger. Similarly, liquid can also be introduced into the inner tube 112 through the second perforated tube 160 to provide a heat exchange medium for the gaseous refrigerant to maintain a high degree of subcooling, and it can also be discharged through the liquid pipe 120 during the continuous liquid inflow process.

[0040] After the gaseous refrigerant completes heat exchange (heat release) between the inner cylinder 112 and the copper tube 113, the high-temperature and high-pressure gaseous refrigerant will condense into liquid in the inner cylinder 112, and the formed liquid can be discharged through the liquid pipe 120; and for the flash gas in the heat exchange process, it can be discharged through the first open hole pipe 150 on the shell and tube heat exchanger, that is, by controlling the third solenoid valve 230 to open, so as to introduce the flash gas into the flash evaporator 250, the flash evaporator 250 works to reduce the flash gas in the shell and tube heat exchanger, thereby increasing the heat exchange area.

[0041] It can be seen that the heat exchanger unit can provide corresponding air intake channels for different operating modes to make more effective use of the heat exchange area, making the heat exchange of the unit more sufficient and helping to improve energy efficiency.

[0042] The present application also provides a heat pump unit, which includes a heat exchanger unit as provided in the above embodiment. The heat pump unit can lead out the flash gas and output liquid refrigerant through the heat exchanger unit. In the heating mode, the heat exchanger unit acts as a condenser, and when the ambient temperature is less than 0°C, the third solenoid valve is opened to replenish air; in the cooling mode, the heat exchanger unit acts as an evaporator, and the flash gas temperature is low at this time, which can be used to reduce the exhaust temperature. Therefore, by using the heat exchanger unit in different operating modes, the heat pump unit can better perform heat exchange to improve the system energy efficiency.

[0043] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0044] Note that the above are only preferred embodiments of the present application and the technical principles used. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A shell and tube heat exchanger, characterized in that: include: A casing body, the casing body comprising an outer cylinder and an inner cylinder which are coaxially arranged and have the same height, the outer cylinder is sleeved outside the inner cylinder, and a copper tube is coiled inside the outer cylinder, the copper tube is coiled inside the outer cylinder around the outer wall of the inner cylinder to form a multi-layer spiral structure, a first perforated tube and a second perforated tube are arranged on the side wall of the casing body, the first perforated tube and the second perforated tube are both used to connect the inner cylinder with the outside, wherein the first perforated tube is also used to release flash gas to the outside, and the second perforated tube is also used to feed liquid into the inner cylinder; a liquid pipe, part of which is located inside the inner tube to connect the inner tube with the outside, and a lower pipe opening of the liquid pipe is away from the bottom of the inner tube, and the lower pipe opening of the liquid pipe is the pipe opening of the part of the liquid pipe located in the inner tube; a first air pipe, the first air pipe being connected to the inner tube and being located at an upper portion of the sleeve body, the upper portion of the sleeve body correspondingly connected to one side of the liquid pipe; The second air pipe is connected to the inner tube and is located at the lower part of the sleeve body. The lower part of the sleeve body is the other side opposite to the upper part.

2. The double-tube heat exchanger according to claim 1, characterized in that: The first perforated tube is located at the upper portion of the casing body, and the second perforated tube is located at the lower portion of the casing body.

3. The double-tube heat exchanger according to claim 2, characterized in that: The distance from the opening position of the first perforated tube corresponding to the inner tube to the top of the inner tube is a first distance, and the first distance is less than or equal to 100 mm.

4. The double-tube heat exchanger according to claim 2 or 3, characterized in that: The diameter of the first perforated tube is greater than or equal to 5 mm and less than or equal to 7 mm.

5. The double-tube heat exchanger according to claim 2, characterized in that: The distance from the opening position of the second perforated tube corresponding to the inner tube to the bottom of the inner tube is a second distance, and the second distance is less than or equal to 50 mm.

6. The double-tube heat exchanger according to claim 2 or 5, characterized in that: The diameter of the second perforated tube is greater than or equal to 5 mm and less than or equal to 7 mm.

7. The double-tube heat exchanger according to claim 1 or 2, characterized in that: A plurality of the first perforated tubes and the second perforated tubes are arranged on the side wall of the sleeve body, and the first perforated tubes and the second perforated tubes are the same in number.

8. The double-tube heat exchanger according to claim 1, characterized in that: The distance from the lower pipe opening of the liquid pipe to the bottom of the inner tube is a third distance, and the third distance is at most one third of the height of the inner tube.

9. A heat exchanger unit, characterized in that: It comprises a first solenoid valve, a second solenoid valve, a third solenoid valve, a three-way valve, a flash evaporator and a shell and tube heat exchanger as claimed in any one of claims 1 to 8; The first gas pipe of the shell and tube heat exchanger is connected to the first solenoid valve, the second gas pipe of the shell and tube heat exchanger is connected to the second solenoid valve, the first solenoid valve and the second solenoid valve are also connected to the three-way valve, the first solenoid valve is used to open in the cooling mode, the second solenoid valve is used to open in the heating mode, and the three-way valve is also used to communicate with one end of the four-way valve; The air inlet port of the flash evaporator is connected to the first perforated tube of the shell-and-tube heat exchanger through the third solenoid valve, and the air outlet port of the flash evaporator is used to communicate with the compressor.

10. A heat pump unit, characterized in that: Comprising a heat exchanger unit as claimed in claim 9.

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