Plate-type evaporator with gas-liquid separation function and heat exchange method

Abstract

The invention relates to the technical field, in particular to a plate-type evaporator with gas-liquid separation and a heat exchange method. The plate-type evaporator comprises a plate-type heat exchanger body and a gas-liquid separator cavity which are fixed to each other; a heat-exchanged fluid inflow pipe, a heat-exchanged fluid outflow pipe, a refrigerant inflow pipe, a refrigerant outflow pipe and a gas-liquid separation pipe are arranged in the gas-liquid separator cavity, and the heat-exchanged fluid inflow pipe, the heat-exchanged fluid outflow pipe and the refrigerant inflow pipe are used for being connected between an external compressor and the plate heat exchanger body. The refrigerant outflow pipe is used for being connected between an external compressor and the gas-liquid separator cavity, and the gas-liquid separation pipe is connected between the upper portion of the plate heat exchanger body and the gas-liquid separator cavity. On the basis of a traditional plate heat exchanger body, the gas-liquid separation cavity is integrated, efficient separation of the gas phase and the liquid phase of a refrigerant is achieved while evaporation heat exchange is completed, an independent gas-liquid separator is omitted, and the problem that the space occupied by the gas-liquid separator is large is solved.

Description

Technical Field

[0001] The present invention relates to the field of heat exchange equipment for refrigeration systems, and in particular to a plate-type evaporator with gas-liquid separation and a heat exchange method. Background Art

[0002] In refrigeration systems, the gas-liquid separator is a key component that prevents liquid refrigerant from entering the compressor and avoids liquid hammer. Existing technical solutions mainly include the following forms: Standalone gas-liquid separators, typically installed on the compressor return line, separate gas and liquid through gravity or centrifugal separation. They employ shell-and-tube or cylinder-type structures, with internal baffles, filters, or cyclones to enhance separation efficiency. Standalone gas-liquid separators require additional space and piping connections.

[0003] Integrated gas-liquid separation heat exchanger. Some technologies attempt to integrate the gas-liquid separation function inside the heat exchanger, such as: the shell and tube heat exchanger with a built-in separation structure: the flow is optimized by positioning the support plate and the separator, but there is still the problem of assembly deviation affecting the heat exchange efficiency.

[0004] Plate heat exchanger combined with separation function: For example, the plate condenser described in patent CN201510970125.1 has separate channels for gas refrigerant and liquid refrigerant, but it still does not completely solve the compactness problem, and the working positions are different. In the refrigeration system, the gas-liquid separator is mainly used to allow the gas to flow back to the compressor.

[0005] Gas-liquid separators with heat exchange functions, such as separators used for CO2 refrigerants, adopt a high-pressure / low-pressure countercurrent heat exchange design, but still have problems such as large flow resistance and limited liquid storage volume.

[0006] However, the above gas-liquid separators all have the following problems: Large space requirements and complex installation: Independent gas-liquid separators require additional piping and welding points, making them difficult to use in compact refrigeration systems (such as energy storage temperature control and vehicle air conditioning). Shell-and-tube heat exchangers also rely on support plates for positioning, which can easily lead to poor refrigerant flow and reduced heat exchange efficiency due to assembly errors.

[0007] It's difficult to balance separation efficiency and heat transfer performance: Traditional separators rely on gravity settling, which has limited effectiveness for separating high-velocity refrigerants (such as R407C), easily allowing liquid refrigerant to enter the compressor. While some integrated designs (such as plate condensers) can improve subcooling, they aren't optimized for evaporation conditions and can't directly replace standalone gas separators.

[0008] Insufficient system reliability: The welds at the independent gas-liquid separator increase the risk of leakage, making it more susceptible to failure, especially in vibrating environments (such as in vehicle air conditioning). Existing technologies are poorly adapted to the temperature glide (4-7°C) of mixed refrigerants (such as R407C), which can cause component separation and affect system stability.

[0009] Therefore, there is an urgent need for a new evaporator that takes up little space, can balance separation efficiency and heat exchange, and has sufficient system reliability to solve the above technical problems. Summary of the Invention

[0010] The main purpose of the present invention is to provide a plate-type evaporator with gas-liquid separation and a heat exchange method, aiming to solve the technical problem that the existing gas-liquid separator occupies a large space.

[0011] To achieve the above-mentioned objectives, the present invention proposes a plate evaporator with gas-liquid separation, comprising a plate heat exchanger body and a gas-liquid separator cavity fixed to each other, wherein a heat exchanged fluid inlet pipe, a heat exchanged fluid outlet pipe, a refrigerant inlet pipe, a refrigerant outlet pipe and a gas-liquid separation pipe are provided in the gas-liquid separator cavity, wherein the heat exchanged fluid inlet pipe, the heat exchanged fluid outlet pipe and the refrigerant inlet pipe are all used to be connected between an external compressor and the plate heat exchanger body, the refrigerant outlet pipe is connected to be connected between an external compressor and the gas-liquid separator cavity, and the gas-liquid separation pipe is connected between the upper part of the plate heat exchanger body and the gas-liquid separator cavity.

[0012] A further improvement of the plate evaporator with gas-liquid separation of the present invention is that the gas-liquid separation tube is in an inverted L-shape, and the end of the gas-liquid separation tube away from the plate heat exchanger body is located in the middle of the gas-liquid separator cavity.

[0013] The plate evaporator with gas-liquid separation of the present invention is further improved in that the refrigerant outflow pipe is L-shaped, the first end of the refrigerant outflow pipe is used to connect to the compressor, and the second end of the refrigerant outflow pipe is located in the middle of the gas-liquid separator cavity.

[0014] The plate evaporator with gas-liquid separation of the present invention is further improved in that the heat exchange fluid inlet pipe is located at the upper position of the gas-liquid separator cavity, and the heat exchange fluid outlet pipe is located at the lower position of the gas-liquid separator cavity.

[0015] A further improvement of the plate-type evaporator with gas-liquid separation of the present invention is that the plate-type heat exchanger body and the gas-liquid separator cavity are isolated by metal plates.

[0016] A further improvement of the plate-type evaporator with gas-liquid separation of the present invention is that the material of the metal plate is stainless steel, copper or aluminum.

[0017] A further improvement of the plate-type evaporator with gas-liquid separation of the present invention is that the material of the heat exchange fluid outflow pipe is copper.

[0018] A further improvement of the plate-type evaporator with gas-liquid separation of the present invention is that an opening for lubricating oil reflux is provided at the bottom of the refrigerant outflow pipe.

[0019] The present invention also provides a heat exchange method using the plate evaporator with gas-liquid separation as described above, wherein the liquid refrigerant enters the plate heat exchanger body from the refrigerant inlet pipe, and after the liquid refrigerant exchanges heat with the heat exchanged fluid entering from the heat exchanged fluid inlet pipe in the plate heat exchanger body, the liquid and gaseous refrigerants enter the gas-liquid separation cavity through the gas-liquid separation pipe. Due to the action of gravity, the liquid refrigerant settles and the gaseous refrigerant rises, and then the refrigerant gas flows back to the compressor through the refrigerant outlet pipe, and the liquid refrigerant continues to exchange heat through the heat exchanged fluid outflow pipe and the metal plates of the plate heat exchanger body and the gas-liquid separator cavity. After evaporating into a gaseous state, it flows back to the compressor from the refrigerant outlet pipe; the heat exchanged fluid flows back to the water pump from the heat exchanged fluid pipe.

[0020] The technical solution of the present invention has the following beneficial effects: The plate evaporator with gas-liquid separation of the present invention adopts an integrated evaporation-gas-liquid separation plate evaporator to reduce installation space. The plate heat exchanger body and the gas-liquid separator cavity are welded together when the heat exchanger is produced, which reduces welding work during on-site assembly. Moreover, by integrating the gas-liquid separation cavity on the basis of the traditional plate heat exchanger body, it can achieve efficient separation of the gas and liquid phases of the refrigerant while completing evaporation heat exchange, thereby eliminating the need for an independent gas-liquid separator and solving the technical problem of the existing gas-liquid separator occupying a large space. The gas-liquid separator cavity of the present invention has a certain accommodating space, which can effectively reduce the refrigerant flow rate. The metal plate is used to separate the plate heat exchanger body and the gas-liquid separator cavity, which can further activate the heat exchange effect on the refrigerant in the gas-liquid separation cavity. The present invention has a simple structure and does not require the installation of an independent gas-liquid separator, thereby reducing pipelines and welding points, reducing manufacturing costs, and is easy to use. The internal flow channel design is optimized, so that evaporation and gas-liquid separation are completed in a single device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0022] Figure 1It is a structural schematic diagram of the plate evaporator with gas-liquid separation of the present invention.

[0023] Description of Figure Numbers: 1. Plate heat exchanger body; 2. Gas-liquid separator cavity; 3. Heat exchange fluid inlet pipe; 4. Heat exchange fluid outflow pipe; 5. Refrigerant inlet pipe; 6. Refrigerant outflow pipe; 7. Gas-liquid separation pipe. DETAILED DESCRIPTION

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0025] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0026] In addition, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referenced. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this disclosure, "plurality" means at least two, such as two or three, unless otherwise specifically defined.

[0027] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0028] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0029] The present invention proposes a plate evaporator with gas-liquid separation, comprising a plate heat exchanger main body 1 and a gas-liquid separator cavity 2 fixed to each other, wherein the gas-liquid separator cavity 2 is provided with a heat exchange fluid inlet pipe 3, a heat exchange fluid outlet pipe 4, a refrigerant inlet pipe 5, a refrigerant outlet pipe 6 and a gas-liquid separation pipe 7, wherein the heat exchange fluid inlet pipe 3, the heat exchange fluid outlet pipe 4 and the refrigerant inlet pipe 5 are all used to be connected between an external compressor and the plate heat exchanger main body 1, the refrigerant outlet pipe 6 is connected to be connected between an external compressor and the gas-liquid separator cavity 2, and the gas-liquid separation pipe 7 is connected between the upper part of the plate heat exchanger main body 1 and the gas-liquid separator cavity 2.

[0030] Specifically, the plate-type evaporator with gas-liquid separation of the present invention can connect the heat exchange fluid inlet pipe 3 and the heat exchange fluid outlet pipe 4 to the desired heat exchange fluid inlet and outlet, as needed. The heat exchange fluid can be disposed around a heat dissipation device using existing technology to absorb heat from the heat dissipation device (such as a battery). The specific structure is not described in detail here. Furthermore, a water pump can be installed at the heat exchange fluid inlet and outlet to provide driving force for the flow of the heat exchange fluid. In this embodiment, the water pump is installed at the heat exchange fluid outlet and connected to the heat exchange fluid pipe 4.

[0031] The reaction principle of the present invention is as follows: the liquid refrigerant enters the plate heat exchanger body 1 from the refrigerant inlet pipe 5. After the liquid refrigerant exchanges heat with the heat exchanged fluid entering from the heat exchanged fluid inlet pipe 3 in the plate heat exchanger body 1, the liquid and gaseous refrigerants enter the gas-liquid separation cavity through the gas-liquid separation pipe 7. Due to the action of gravity, the liquid refrigerant settles and the gaseous refrigerant rises. Then the refrigerant gas flows back to the compressor through the refrigerant outlet pipe 6. The liquid refrigerant continues to exchange heat through the heat exchanged fluid outflow pipe 4 and the metal plates of the plate heat exchanger body 1 and the gas-liquid separator cavity 2. After evaporating into a gaseous state, it flows back to the compressor from the refrigerant outlet pipe 6; the heat exchanged fluid flows back to the water pump from the heat exchanged fluid pipe 4.

[0032] In this embodiment, the compressor can be a horizontal compressor to adapt to low moisture content suction and reduce the risk of liquid hammer. In addition, the present invention also provides an expansion valve at the front end of the refrigerant inlet pipe 3 to control the superheat and avoid excessive refrigerant supply.

[0033] The present invention integrates the gas-liquid separation function on the basis of the traditional plate heat exchanger through structural optimization design. The gas-liquid separator cavity 2 can also be integrated into the horizontal compressor or the gas-liquid separator cavity 2 can be made into a centrifugal type, so that it can achieve efficient separation of the gas and liquid phases of the refrigerant while completing the evaporation heat exchange, thereby eliminating the need for an independent gas-liquid separator. In this embodiment, the plate heat exchanger body 1 is a traditional plate heat exchanger, which uses the inertial force and gravity effect of the refrigerant flow to naturally separate the gas and liquid refrigerants in the gas-liquid separator cavity 2 at a low flow rate. The present invention has a space-saving structure, eliminates the need for an independent gas-liquid separator and complex piping, and is suitable for compact systems; reduces welding points and material usage, simplifies the assembly process, and has the effect of reducing costs; the present invention can avoid the risk of leakage of external gas separation, while ensuring dry compression of the compressor and improving reliability; the integrated design of the present invention reduces flow resistance, improves heat exchange efficiency, and optimizes energy efficiency.

[0034] Preferably, the gas-liquid separation tube 7 is in an inverted L-shape, with the end of the gas-liquid separation tube 7 away from the plate heat exchanger body 1 being located in the middle of the gas-liquid separator cavity 2. Specifically, the bend of the gas-liquid separation tube 7 is arc-shaped, thereby facilitating smooth outflow of both liquid and gaseous refrigerants from the gas-liquid separation tube 7.

[0035] Preferably, the refrigerant outflow pipe 6 is L-shaped, with the first end of the refrigerant outflow pipe 6 being connected to the compressor, and the second end of the refrigerant outflow pipe 6 being located in the middle of the gas-liquid separator cavity 2. Specifically, the refrigerant inflow pipe 5 is located in the lower middle portion of the gas-liquid separator cavity 2 and connected to the plate heat exchanger body 1, so that the refrigerant enters the plate heat exchanger body 1 to exchange heat with the heat exchanged fluid, and then enters the gas-liquid separation cavity through the gas-liquid separation pipe 7, which is connected to the upper portion of the plate heat exchanger body 1. The refrigerant flow direction of the plate heat exchanger body 1, which enters from the bottom and exits from the top, is combined with the effect of gravity to ensure that the liquid refrigerant is retained at the bottom of the plate heat exchanger body 1, and the gaseous refrigerant enters the gas-liquid separation pipe 7 from the top and enters the gas-liquid separation cavity, and finally enters the compressor through the refrigerant outflow pipe 6.

[0036] Preferably, the heat exchange fluid inlet pipe 3 is located at the upper position of the gas-liquid separator cavity 2, and the heat exchange fluid outlet pipe 4 is located at the lower position of the gas-liquid separator cavity 2, thereby realizing heat exchange and circulation of the heat exchange fluid.

[0037] Furthermore, a metal plate is used to separate the plate heat exchanger body 1 and the gas-liquid separator cavity 2. Preferably, the metal plate is made of stainless steel, copper, or aluminum. Due to the good heat conduction effect of the metal plate, the liquid refrigerant settles to the bottom by gravity, exchanges heat with the plate heat exchanger body 1 through the metal plate, and then evaporates into gas.

[0038] Preferably, the material of the heat exchange fluid outflow pipe 4 is copper. Since copper has good heat conduction effect, the liquid refrigerant continues to exchange heat with the heat exchange fluid outflow pipe 4 and evaporates into gas.

[0039] Preferably, an opening for lubricating oil return is provided at the bottom of the refrigerant outflow pipe 6 so that the lubricating oil accumulated at the bottom can return to the compressor.

[0040] The plate evaporator with gas-liquid separation of the present invention utilizes an integrated evaporation and gas-liquid separation plate evaporator, reducing installation space. The plate heat exchanger body 1 and the gas-liquid separator cavity 2 are welded together during heat exchanger production, reducing welding work during on-site assembly. Furthermore, by integrating the gas-liquid separation cavity with the traditional plate heat exchanger body 1, the plate heat exchanger achieves efficient separation of the gas and liquid phases of the refrigerant while completing evaporation heat exchange, thereby eliminating the need for a separate gas-liquid separator and resolving the technical issue of existing gas-liquid separators requiring large space. The gas-liquid separator cavity 2 of the present invention has a certain amount of accommodation space, which can effectively reduce the refrigerant flow rate. The portion separating the plate heat exchanger body 1 and the gas-liquid separator cavity 2 is also constructed of a metal plate, which can further heat the refrigerant in the gas-liquid separation cavity. The present invention has a simple structure, eliminating the need for an additional separate gas-liquid separator, thereby reducing piping and welding points, lowering manufacturing costs, and facilitating ease of use. The optimized internal flow channel design allows evaporation and gas-liquid separation to be completed within a single device.

[0041] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A plate evaporator with gas-liquid separation, characterized in that: The invention comprises a plate heat exchanger body (1) and a gas-liquid separator cavity (2) fixed to each other, wherein a heat exchange fluid inlet pipe (3), a heat exchange fluid outlet pipe (4), a refrigerant inlet pipe (5), a refrigerant outlet pipe (6) and a gas-liquid separation pipe (7) are provided in the gas-liquid separator cavity (2), wherein the heat exchange fluid inlet pipe (3), the heat exchange fluid outlet pipe (4) and the refrigerant inlet pipe (5) are all used to be connected between an external compressor and the plate heat exchanger body (1), the refrigerant outlet pipe (6) is connected between an external compressor and the gas-liquid separator cavity (2), and the gas-liquid separation pipe (7) is connected between the upper part of the plate heat exchanger body (1) and the gas-liquid separator cavity (2).

2. The plate evaporator with gas-liquid separation according to claim 1, characterized in that: The gas-liquid separation tube (7) is in an inverted L-shape, and one end of the gas-liquid separation tube (7) away from the plate heat exchanger body (1) is located in the middle of the gas-liquid separator cavity (2).

3. The plate evaporator with gas-liquid separation according to claim 2, characterized in that: The refrigerant outflow pipe (6) is L-shaped, a first end of the refrigerant outflow pipe (6) is used to be connected to a compressor, and a second end of the refrigerant outflow pipe (6) is located in the middle of the gas-liquid separator cavity (2).

4. The plate evaporator with gas-liquid separation according to claim 3, characterized in that: The heat exchange fluid inflow pipe (3) is located at the upper position of the gas-liquid separator cavity (2), and the heat exchange fluid outflow pipe (4) is located at the lower position of the gas-liquid separator cavity (2).

5. The plate evaporator with gas-liquid separation according to claim 4, characterized in that: The plate heat exchanger body (1) and the gas-liquid separator cavity (2) are isolated by metal plates.

6. The plate evaporator with gas-liquid separation according to claim 5, characterized in that: The metal plate is made of stainless steel, copper or aluminum.

7. The plate evaporator with gas-liquid separation according to claim 6, characterized in that: The material of the heat exchange fluid outflow pipe (4) is copper.

8. The plate evaporator with gas-liquid separation according to claim 7, characterized in that: The bottom of the refrigerant outflow pipe (6) is provided with an opening for lubricating oil reflux.

9. A heat exchange method using the plate evaporator with gas-liquid separation as claimed in claim 8, characterized in that: The liquid refrigerant enters the plate heat exchanger body (1) from the refrigerant inlet pipe (5). After the liquid refrigerant exchanges heat with the heat exchanged fluid entering from the heat exchanged fluid inlet pipe (3) in the plate heat exchanger body (1), the liquid and gaseous refrigerants enter the gas-liquid separation cavity through the gas-liquid separation pipe (7). Due to the action of gravity, the liquid refrigerant settles and the gaseous refrigerant rises. Then, the refrigerant gas flows back to the compressor through the refrigerant outlet pipe (6). The liquid refrigerant continues to exchange heat through the heat exchanged fluid outlet pipe (4) and the metal plates of the plate heat exchanger body (1) and the gas-liquid separator cavity (2). After evaporating into gaseous state, it flows back to the compressor from the refrigerant outlet pipe (6); the heat exchanged fluid flows back to the water pump from the heat exchanged fluid pipe (4).

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