Falling film evaporator

Abstract

The utility model provides a falling film evaporator which comprises a heat exchange shell and a heat exchange pipe, the heat exchange shell is provided with a heat exchange inner cavity, the heat exchange pipe is installed in the heat exchange inner cavity, a central pipe is arranged in the middle of the heat exchange inner cavity, and a plurality of spraying holes capable of spraying refrigerants to the heat exchange pipe are formed in the central pipe. The center pipe is provided with a center cavity which can be communicated with the heat exchange inner cavity through the spraying holes, the center cavity is communicated with a refrigerant liquid inlet pipe, an oil storage cavity is arranged below the center cavity, and an oil return hole communicated with the heat exchange inner cavity is formed in the oil storage cavity. The structure is simple, refrigerants are sprayed out of the heat exchange inner cavity at different heights, the heat exchange pipes can make full contact with the refrigerants, the effective utilization rate of the heat exchange pipes is increased, meanwhile, the flowing speed of the refrigerants is increased, resistance to the refrigerants is reduced, the probability that oil films are formed on the heat exchange pipes is reduced, the heat exchange efficiency is improved, and inlet and outlet oil balance of the compressor can be guaranteed; the problem of oil shortage of the compressor is avoided.

Description

Technical Field

[0001] This utility model relates to the technical field of evaporators, specifically a falling film evaporator. Background Technology

[0002] With the continuous improvement of living standards, existing heat pump systems are widely used, utilizing the heat absorption and release phenomena generated by the liquid and gas phase changes of the refrigerant. For example, in the air conditioning cooling process, the refrigerant is drawn into the compressor and compressed, then releases heat and condenses into a liquid in the condenser. It then passes through a throttling device to reduce its pressure, and finally enters the heat exchanger to absorb heat and evaporate, returning to the compressor as vapor, thus realizing the refrigeration cycle and regulating the temperature of the medium or the surrounding environment. In the air conditioning heating process, the refrigerant is drawn into the compressor and compressed, then releases heat and condenses in the heat exchanger. It then passes through a throttling device to reduce its pressure, and finally enters the evaporator to absorb heat and evaporate into a gas, flowing back to the compressor.

[0003] Most of the evaporators mentioned above are flooded evaporators, which are the most common heat exchange components. They mainly include a heat exchange shell for storing refrigerant and heat exchange tubes for the flow of the medium. The heat exchange shell has a heat exchange cavity, and the heat exchange tubes are installed in the heat exchange cavity. The liquid inlet end and liquid outlet end of the heat exchange tubes are respectively connected to a medium input pipe and a medium output pipe. At the same time, the heat exchange cavity is connected to a refrigerant input pipe and a refrigerant output pipe.

[0004] During operation, the refrigerant and refrigeration oil undergo large-space boiling within the evaporator shell, resulting in high energy efficiency.

[0005] However, existing evaporators have the following shortcomings during use:

[0006] 1) The refrigerant can only be sprayed on one side of its heat exchange cavity, resulting in uneven refrigerant distribution.

[0007] 2) The refrigerant in the heat exchange cavity is subject to high damping and has low fluidity, which can easily cause an oil film to form on the heat exchange tubes, reducing the heat exchange efficiency.

[0008] 3) The location of the refrigerant spray nozzle results in low heat exchange efficiency due to low refrigerant flow, and a large amount of refrigeration oil accumulates in the heat exchange tank, which will cause the compressor to lack oil and affect the normal use of the compressor. Summary of the Invention

[0009] The purpose of this invention is to address the shortcomings of existing technologies by proposing a falling film evaporator.

[0010] The objective of this invention is achieved as follows: A falling film evaporator includes a heat exchange shell for storing refrigerant and a heat exchange tube for the flow and heat exchange of the medium. The heat exchange shell has a heat exchange inner cavity, and the heat exchange tube is installed in the heat exchange inner cavity. A central tube is provided in the middle of the heat exchange inner cavity. The central tube has several spray holes for spraying refrigerant onto the heat exchange tube. The central tube has a central cavity that can communicate with the heat exchange inner cavity through the spray holes. The central cavity is connected to a refrigerant inlet pipe, and an oil storage cavity is provided below the central cavity. The oil storage cavity has an oil return hole that communicates with the heat exchange inner cavity.

[0011] Based on the above optimization, the number of oil return holes is at least two, and the oil return holes are equally spaced at the bottom of the oil storage cavity.

[0012] Based on the above optimization, the heat exchange shell is provided with an oil return pipe, the inlet of the oil return pipe is connected to the oil storage chamber, and the outlet of the oil return pipe is connected to the compressor.

[0013] Based on the above optimization, the oil storage chamber has an oil outlet connected to the oil return pipe, and the height of the oil outlet is lower than that of the oil return hole.

[0014] Based on the above optimization, the heat exchange tubes are wound around the outer wall of the central tube from top to bottom, so that the heat exchange tubes form sensible heat exchange tube sections and subcooled heat exchange tube sections with equal pitch, and the plurality of spray holes are distributed from top to bottom and corresponding to the sensible heat exchange tube sections and subcooled heat exchange tube sections.

[0015] Based on the above optimization, the refrigerant inlet pipe is installed on the top of the heat exchange shell, and the inlet end of the refrigerant inlet pipe is connected to an external refrigerant supply source, while the outlet end of the refrigerant inlet pipe penetrates the heat exchange shell and extends to the bottom of the central cavity.

[0016] Based on the above optimization, the heat exchange shell is provided with a refrigerant outlet pipe, a medium inlet pipe and a medium outlet pipe. The medium inlet pipe and the medium outlet pipe are diagonally distributed on the heat exchange shell and are connected to the liquid inlet and liquid outlet of the heat exchange tube. The refrigerant outlet pipe is installed on the upper part of the heat exchange shell and is connected to the heat exchange inner cavity.

[0017] The advantages of this utility model are:

[0018] 1) Several spray holes are provided through the central tube, and refrigerant is sprayed into the heat exchange cavity at different heights, so that the sensible heat exchange tubes and subcooled heat exchange tubes can fully contact the refrigerant, increase the effective utilization rate of the heat exchange tubes, thereby increasing the overall cooling capacity of the evaporator. At the same time, it accelerates the refrigerant flow rate, reduces the resistance of the refrigerant, reduces the probability of oil film formation on the heat exchange tubes, and improves the heat exchange efficiency.

[0019] 2) The combination of a central tube and a spray nozzle structure can prevent refrigerant misflow and improve heat exchange efficiency.

[0020] 3) By utilizing the structural combination of the oil storage chamber and the oil return pipe, the refrigerant oil accumulated in the evaporator can be returned to the compressor through the oil return pipe, ensuring the oil balance in and out of the compressor and avoiding problems caused by insufficient oil in the compressor. Attached Figure Description

[0021] Appendix Figure 1 This is a schematic diagram of a preferred embodiment of the present invention.

[0022] Appendix Figure 2 This is a cross-sectional view of a preferred embodiment of the present invention. Detailed Implementation

[0023] The present invention will now be further described with reference to the accompanying drawings.

[0024] According to the appendix Figures 1 to 2 As shown, the falling film evaporator of this utility model includes a heat exchange shell 1 for storing refrigerant and a heat exchange tube 2 for the flow and heat exchange of the refrigerant. The heat exchange shell 1 has a heat exchange cavity 11, and the heat exchange tube 2 is installed in the heat exchange cavity 11. A central tube 3 is provided in the middle of the heat exchange cavity 11, and the central tube 3 has several spray holes 31 for spraying refrigerant onto the heat exchange tube 2. The central tube 3 has a central cavity 32 that communicates with the heat exchange cavity 11 through the spray holes 31. The central cavity 32 is connected to a refrigerant inlet pipe 4, and an oil storage cavity 12 is provided below the central cavity 32. The oil storage cavity 12 has an oil return hole 13 that communicates with the heat exchange cavity 11.

[0025] Reference Figures 1 to 2 As shown, in further detail, the heat exchange tube 2 is coiled around the outer wall of the central tube 3 from top to bottom, so that the heat exchange tube 2 forms sensible heat exchange tube sections and subcooled heat exchange tube sections with equal pitch, and the plurality of spray holes 31 are distributed from top to bottom and corresponding to the sensible heat exchange tube sections and subcooled heat exchange tube sections.

[0026] Furthermore, the refrigerant inlet pipe 4 is installed on the top of the heat exchange shell 1, and the inlet end of the refrigerant inlet pipe 4 is connected to an external refrigerant supply source, while the outlet end of the refrigerant inlet pipe 4 penetrates the heat exchange shell 1 and extends to the bottom of the central cavity 32.

[0027] Thus, the refrigerant inlet pipe 4 is installed on the top of the heat exchange shell 1, and the inlet end of the refrigerant inlet pipe 4 is connected to an external refrigerant supply source, while the outlet end of the refrigerant inlet pipe 4 penetrates the heat exchange shell 1 and extends to the bottom of the central cavity 32.

[0028] Reference Figures 1 to 2As shown, further detailed, the heat exchange shell 1 is provided with a refrigerant outlet pipe 5, a medium inlet pipe 6 and a medium outlet pipe 7. The medium inlet pipe 6 and the medium outlet pipe 7 are diagonally distributed on the heat exchange shell 1 and are connected to the liquid inlet and liquid outlet of the heat exchange tube 2. The refrigerant outlet pipe 5 is installed on the upper part of the heat exchange shell 1 and is connected to the heat exchange inner cavity 11.

[0029] During operation, refrigerant enters the central cavity 32 of the central tube 3 through the refrigerant inlet pipe. As the amount of refrigerant in the central cavity 32 increases, it is sprayed through spray holes 31 at different heights onto the heat exchange tubes 2 at different positions in the heat exchange inner cavity 11, releasing heat during the vaporization and condensation of the refrigerant. Meanwhile, water enters the heat exchange tubes 2 through the medium inlet pipe 6, and the water in the heat exchange tubes 2 is heated by fully utilizing the sensible and latent heat of the refrigerant. Subsequently, the resulting hot water is discharged through the medium outlet pipe 7. Simultaneously, the vaporized refrigerant can be discharged from the refrigerant suction pipe towards the compressor.

[0030] By using a structure that combines the central tube 3 with the injection hole, refrigerant flow deviation can be avoided, thus improving heat exchange efficiency.

[0031] Reference Figures 1 to 2 As shown, to further refine the details, the number of oil return holes 13 is at least two, and the oil return holes 13 are equally spaced at the bottom of the oil storage cavity 12.

[0032] Furthermore, the heat exchange shell 1 is provided with an oil return pipe 8, the inlet of which is connected to the oil storage chamber 12, and the outlet of which is connected to a compressor.

[0033] By utilizing the structural cooperation between the oil storage chamber 12 and the oil return pipe 8, the refrigerant oil accumulated in the evaporator can be returned to the compressor through the oil return pipe 8, ensuring the oil balance in and out of the compressor and avoiding problems caused by insufficient oil in the compressor.

[0034] The above specific embodiments are only specific implementations of the present invention with better effects. All structures that are the same as or equivalent to the falling film evaporator of the present invention are within the protection scope of the present invention.

Claims

1. A falling film evaporator comprising a heat exchange shell (1) for storing refrigerant and a heat exchange tube (2) for passing a medium therethrough for heat exchange, said heat exchange shell (1) having a heat exchange inner cavity (11), said heat exchange tube (2) being installed in the heat exchange inner cavity (11), characterized in that: The heat exchange inner cavity (11) is provided with a central tube (3) in the middle. The central tube (3) has several spray holes (31) for spraying refrigerant into the heat exchange tube (2). The central tube (3) is provided with a central cavity (32) that can be connected to the heat exchange inner cavity (11) through the spray holes (31). The central cavity (32) is connected to a refrigerant inlet pipe (4). An oil storage cavity (12) is provided below the central cavity (32). The oil storage cavity (12) has an oil return hole (13) that is connected to the heat exchange inner cavity (11).

2. The falling film evaporator of claim 1, wherein: The number of oil return holes (13) is at least two, and the oil return holes (13) are equally spaced at the bottom of the oil storage cavity (12).

3. The falling film evaporator of claim 1, wherein: The heat exchange shell (1) is provided with an oil return pipe (8), the inlet of the oil return pipe (8) is connected to the oil storage chamber (12), and the outlet of the oil return pipe (8) is connected to a compressor.

4. The falling film evaporator of claim 1, wherein: The oil storage chamber (12) has an oil outlet that communicates with the oil return pipe (8), and the height of the oil outlet is lower than that of the oil return hole (13).

5. The falling film evaporator of claim 1, wherein: The heat exchange tube (2) is coiled from top to bottom around the outer wall of the central tube (3) so that the heat exchange tube (2) forms sensible heat exchange tube sections and subcooled heat exchange tube sections with equal pitch. The plurality of spray holes (31) are distributed from top to bottom and corresponding to the sensible heat exchange tube sections and subcooled heat exchange tube sections.

6. The falling film evaporator according to claim 1, characterized in that: The refrigerant inlet pipe (4) is installed on the top of the heat exchange shell (1), and the inlet end of the refrigerant inlet pipe (4) is connected to an external refrigerant supply source. The outlet end of the refrigerant inlet pipe (4) penetrates the heat exchange shell (1) and extends to the bottom of the central cavity (32).

7. The falling film evaporator of claim 1, wherein: The heat exchange shell (1) is provided with a refrigerant outlet pipe (5), a medium inlet pipe (6) and a medium outlet pipe (7). The medium inlet pipe (6) and the medium outlet pipe (7) are diagonally distributed on the heat exchange shell (1) and are connected to the liquid inlet and liquid outlet of the heat exchange tube (2). The refrigerant outlet pipe (5) is installed on the upper part of the heat exchange shell (1) and is connected to the heat exchange inner cavity (11).

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