A shell-and-tube evaporator

Abstract

This utility model relates to the field of evaporators, specifically to a shell-and-tube evaporator, comprising a shell and a distribution assembly. The shell contains a heat exchange tube bundle, and the distribution assembly includes a distribution plate. The distribution plate is closer to the refrigerant inlet than the heat exchange tube bundle. A cavity is formed between the distribution plate and the shell, and a filler is provided within the cavity. The proportion of the filler's volume in the cavity is adapted to the refrigerant flow distribution along the length of the distribution plate. Through the arrangement of the distribution plate and the filler, the cross-sectional area of ​​the cavity for refrigerant liquid flow is adapted to the refrigerant flow distribution along the length of the distribution plate, achieving a more uniform distribution of refrigerant liquid velocity in the axial direction of the heat exchange tube bundle. While ensuring the evaporator's cooling capacity, this effectively reduces the overall required refrigerant liquid charge, ultimately improving the overall heat exchange efficiency and operational stability of the shell-and-tube evaporator.

Description

Technical Field

[0001] This utility model relates to the field of evaporators, specifically to a shell-and-tube evaporator. Background Technology

[0002] Currently, large-scale refrigeration systems mainly employ vapor compression refrigeration cycles. These systems consist of compressors, condensers, throttling devices, evaporators, and various auxiliary equipment. Refrigerant vapor is discharged from the compressor and enters the condenser for cooling and condensation into a liquid state. It then passes through the throttling device, where its pressure is reduced, and enters the evaporator to evaporate and produce a cooling effect. Finally, the refrigerant vapor flows back to the compressor, completing one refrigeration cycle. The evaporator is a crucial component of the refrigeration system. A flooded evaporator is a type of evaporator whose main principle is that liquid refrigerant fills the evaporator shell side, exchanging heat with the heat exchange medium within the heat exchange tube bundle.

[0003] However, existing flooded evaporators suffer from uneven refrigerant distribution within the evaporator, resulting in either too much or too little refrigerant in certain areas of the tube bundle. Insufficient refrigerant means the tube bundle cannot be fully submerged, failing to utilize the evaporator's heat exchange area and thus reducing its cooling capacity. Conversely, excessive refrigerant in certain areas can lead to an overcharge of refrigerant. Utility Model Content

[0004] The technical solution adopted by this utility model to solve its technical problem is: to provide a shell-and-tube evaporator, comprising:

[0005] The housing has a refrigerant inlet and a refrigerant outlet, and a heat exchange tube bundle is provided inside the housing. The heat exchange tube bundle includes at least two sets of tube bundles, and multiple sets of tube bundles are arranged sequentially along the flow direction of the refrigerant liquid.

[0006] The distribution assembly includes a distribution plate, which is closer to the refrigerant inlet than the heat exchange tube bundle. The distribution plate has distribution holes, and a cavity is formed between the distribution plate and the shell. The cavity is filled with a filler, and the proportion of the filler occupying the cavity volume is adapted to the flow distribution of the refrigerant liquid along the length of the distribution plate.

[0007] Furthermore, the distribution assembly also includes at least one equalization plate located between two adjacent tube bundles, and the equalization plate is provided with multiple flow equalization holes.

[0008] Furthermore, the heat exchange tube bundle includes two sets of tube bundles, namely a first tube bundle and a second tube bundle. The first tube bundle is closer to the refrigerant inlet than the second tube bundle. An equalization plate is provided and is located between the first tube bundle and the second tube bundle.

[0009] Furthermore, the heat exchange tube bundle includes three sets of tube bundles, namely a first tube bundle, a second tube bundle, and a third tube bundle. The first tube bundle, the second tube bundle, and the third tube bundle are arranged sequentially along the refrigerant liquid flow direction, and the first tube bundle is closer to the refrigerant inlet than the third tube bundle. There are two equalization plates, which are located between the first tube bundle and the second tube bundle, and between the second tube bundle and the third tube bundle, respectively.

[0010] Furthermore, the length of the distribution plate is the same as the length of the housing.

[0011] Furthermore, the refrigerant inlet is located at the middle of the length of the casing.

[0012] Furthermore, the diameter of the flow equalization orifice is 5mm-10mm.

[0013] Furthermore, the total cross-sectional area of ​​the flow equalization holes is 60%-80% of the cross-sectional area of ​​the equalization plate.

[0014] Furthermore, the gap between the first tube bundle and the distribution plate is 1mm-3mm.

[0015] Furthermore, a filler material 2 is provided between the heat exchange tube bundle and the shell.

[0016] The beneficial effects of this utility model are as follows: By setting the distribution plate and the filler material, and ensuring that the proportion of the filler material occupying the cavity volume is matched with the flow distribution of the refrigerant liquid along the length of the distribution plate, the cross-sectional area of ​​the cavity for refrigerant liquid flow is matched with the flow distribution of the refrigerant liquid along the length of the distribution plate. This achieves a more uniform distribution of the refrigerant velocity in the axial direction of the heat exchange tube bundle, reducing the problem of insufficient heat exchange area and reduced cooling capacity caused by insufficient refrigerant liquid in some tube bundles being exposed to the gas phase, as well as the problem of liquid accumulation caused by excessive refrigerant liquid in some tube bundles. While ensuring the cooling capacity of the evaporator, it effectively reduces the overall required refrigerant liquid charge, ultimately improving the overall heat exchange efficiency and operational stability of the shell-and-tube evaporator. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] In the picture: Figure 1 A cross-sectional view of a shell-and-tube evaporator provided in Embodiment 1 of this utility model;

[0019] Figure 2 This is a cross-sectional view of a shell-and-tube evaporator provided in Embodiment 2 of the present invention;

[0020] Figure 3 for Figure 1The diagram shows a shell-and-tube evaporator from a frontal view (solid arrows indicate the flow direction of the refrigerant, and hollow arrows indicate the flow direction of the heat exchange medium inside the shell-and-tube evaporator).

[0021] Figure 4 for Figure 2 The diagram shows a shell-and-tube evaporator from a frontal view (solid arrows indicate the flow direction of the refrigerant, and hollow arrows indicate the flow direction of the heat exchange medium inside the shell-and-tube evaporator).

[0022] Figure 5 for Figure 1 The diagram shows the three-dimensional structure of the distribution plate.

[0023] Explanation of reference numerals in the attached drawings: 10, shell; 11, refrigerant inlet; 12, refrigerant outlet; 13, end cap; 131, heat exchange inlet; 132, heat exchange outlet; 133, partition plate; 20, distribution plate; 21, distribution hole; 30, equalization plate; 40, first tube bundle; 50, second tube bundle; 60, third tube bundle. Detailed Implementation

[0024] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will now be described in detail with reference to the accompanying drawings. This drawing is a simplified schematic diagram, illustrating only the basic aspects of the present utility model, and therefore only shows the components relevant to the present utility model. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0025] Example 1

[0026] Please refer to Figure 1 and Figure 3This utility model provides a shell-and-tube evaporator, including a shell 10 and a distribution assembly disposed within the shell 10. The shell 10 is provided with a refrigerant inlet 11 and a refrigerant outlet 12. A heat exchange tube bundle is disposed within the shell 10, comprising at least two sets of tube bundles arranged sequentially along the flow direction of the refrigerant liquid. The refrigerant inlet 11 is located at the middle and bottom of the shell 10 along its length, while the refrigerant outlet 12 is located at the top of the shell 10. End caps 13 are provided at both ends along the length of the shell 10, each end cap having a heat exchange inlet 131 and a heat exchange outlet 132. The heat exchange medium flows into the heat exchange tube bundle from the heat exchange inlet 131 and then flows out of the shell 10 along the heat exchange tube bundle and the heat exchange outlet 132, where it exchanges heat with the refrigerant, causing the refrigerant liquid to turn into a gas, which then flows out of the shell 10 along the refrigerant outlet 12. The end cap 13 is provided with a baffle 133, which is used to restrict the flow direction of the heat exchange medium in the heat exchange tube bundle.

[0027] It is understood that the tube bundle described in this utility model includes multiple heat exchange tubes; for ease of demonstration, Figure 3 The tube bundle in the diagram is not shown as multiple heat exchange tubes.

[0028] Please refer to Figure 1 , Figure 3 and Figure 5 The distribution assembly includes a distribution plate 20, which is located closer to the refrigerant inlet 11 than the heat exchange tube bundle. The distribution plate 20 is used to distribute liquid refrigerant, and a distribution hole 21 is provided on the distribution plate 20. The liquid refrigerant flows into the next shell side through the distribution hole 21. A cavity is formed between the distribution plate 20 and the shell 10, and a filler (not shown in the figure) is provided in the cavity. The proportion of the cavity volume occupied by the filler is adapted to the flow distribution of the liquid refrigerant along the length of the distribution plate 20.

[0029] The gap between the first tube bundle 40 and the distribution plate 20 is 1mm-3mm. The first tube bundle 40 is close to the container shell 10 to reduce the dead zone volume. To further reduce the dead zone between the heat exchange tube bundle and the shell 10, a second filler (not shown in the figure) is provided between the heat exchange tube bundle and the shell 10. The second filler can reduce the dead zone between the heat exchange tube bundle and the shell 10 and guide the refrigerant liquid, allowing the refrigerant liquid to flow onto the heat exchange tube bundle. Specifically, both the first and second fillers are plastic, but other materials can also be used.

[0030] Specifically, the total width of the first tube bundle 40 on the circular cross-section of the housing 10 is greater than 90% of the diameter of the cross-section of the housing 10. Preferably, in this embodiment, the total volume of the first tube bundle 40 is 95% of the internal volume of the housing 10.

[0031] After the refrigerant liquid enters the housing 10 through the refrigerant inlet 11, the flow rate is the highest at the refrigerant inlet 11 and gradually decreases towards both ends along the length of the distribution plate 20, and the corresponding flow velocity of the refrigerant liquid also decreases. In order to keep the flow velocity of the refrigerant liquid uniform throughout the housing 10 as it flows from the refrigerant inlet 11, and to ensure that the flow rate of the refrigerant liquid through the cavity at the corresponding position remains constant, the smaller the cross-sectional area of ​​the cavity through which the refrigerant liquid flows, the greater the flow velocity of the refrigerant liquid at the corresponding position. Therefore, the proportion of the filler material on the distribution plate 20 corresponding to the refrigerant inlet 11 occupying the cavity volume at that position is the smallest, and it gradually increases at both ends along the length of the distribution plate 20, so that the filler material in the cavity is thick at both ends and thin in the middle or absent along the length of the distribution plate 20.

[0032] Correspondingly, the cross-sectional area for refrigerant liquid to flow in the cavity at the refrigerant inlet 11 on the distribution plate 20 is the largest. The cross-sectional area for refrigerant liquid to flow in the cavity on the distribution plate 20 gradually decreases towards both ends along the length of the distribution plate 20. This reduces the flow velocity of the refrigerant liquid with the highest flow velocity at the corresponding refrigerant inlet 11, while increasing the flow velocity of the refrigerant liquid extending towards both ends along the length of the distribution plate 20. Ultimately, this ensures that the flow velocity of the refrigerant liquid flowing into the next tube bundle after passing through the distribution plate 20 remains uniform along the length of the distribution plate 20.

[0033] By configuring the distribution plate 20 and the filler material, and ensuring that the proportion of the filler material occupying the cavity volume is matched with the flow distribution of the refrigerant liquid along the length of the distribution plate 20, the cross-sectional area of ​​the cavity for refrigerant liquid flow is matched with the flow distribution of the refrigerant liquid along the length of the distribution plate 20. This achieves a more uniform distribution of the refrigerant liquid flow velocity in the axial direction of the heat exchange tube bundle, reducing the problems of insufficient refrigerant liquid in some tube bundles being exposed to the gas phase, resulting in insufficient heat exchange area and reduced cooling capacity, as well as the problem of excessive refrigerant liquid causing liquid accumulation in some tube bundles. While ensuring the cooling capacity of the evaporator, this effectively reduces the overall required refrigerant liquid charge, ultimately improving the overall heat exchange efficiency and operational stability of the shell-and-tube evaporator.

[0034] For details, please refer to Figure 1 and Figure 3 In this embodiment, the heat exchange tube bundle includes three sets of tube bundles, namely the first tube bundle 40, the second tube bundle 50 and the third tube bundle 60. The first tube bundle 40, the second tube bundle 50 and the third tube bundle 60 are arranged sequentially along the refrigerant liquid flow direction, and the first tube bundle 40 is closer to the refrigerant inlet 11 than the third tube bundle 60.

[0035] When the heat exchange tube bundle includes three sets of tube bundles, the heat exchange inlet 131 and the heat exchange outlet 132 are respectively located on the two end caps 13 at both ends of the shell 10 in the length direction. Two partitions 133 are provided, and the two partitions 133 are respectively located on the two end caps 13. The partition 133 near the heat exchange inlet 131 is used to separate the first tube bundle 40 and the second tube bundle 50, and the partition 133 near the heat exchange outlet 132 is used to separate the second tube bundle 50 and the third tube bundle 60.

[0036] After being distributed by the distribution plate 20, the refrigerant liquid exchanges heat with the heat exchange medium at the first tube bundle 40 and becomes refrigerant gas. In order to make the refrigerant gas escape more evenly, the distribution assembly also includes at least one equalization plate 30. The equalization plate 30 is used to distribute the refrigerant gas. The equalization plate 30 is located between two adjacent tube bundles. The equalization plate 30 is provided with multiple flow equalization holes. In order to make the refrigerant gas escape evenly through the equalization plate 30, the flow equalization holes are evenly distributed on the equalization plate 30.

[0037] Specifically, in this embodiment, two equalization plates 30 are provided. The diameter of the flow equalization holes between the two equalization plates 30 and the first tube bundle 40 and the second tube bundle 50, and between the second tube bundle 50 and the third tube bundle 60, is 5mm-10mm. Specifically, in this embodiment, the lengths of the distribution plate 20 and the equalization plate 30 are the same as the length of the housing 10, and both the distribution plate 20 and the equalization plate 30 are parallel to each other. The cross-sectional shapes of the distribution plate 20 and the equalization plate 30 are set according to the tube bundle arrangement. Figure 5 The shape of the distribution plate 20 shown is only one. The flow velocity of the distribution plate 20 is greater than 5 m / s. The flow velocity of the distribution plate 20 is controlled by the proportion of the volume occupied by the filler in the cavity. The total cross-sectional area of ​​the equalization holes is 60%-80% of the cross-sectional area of ​​the equalization plate 30.

[0038] Example 2

[0039] Please refer to Figure 2 and Figure 4 The difference between this embodiment and Embodiment 1 is that the heat exchange tube bundle includes two sets of tube bundles, namely the first tube bundle 40 and the second tube bundle 50. The first tube bundle 40 is closer to the refrigerant inlet 11 than the second tube bundle 50. An equalization plate 30 is provided and is located between the first tube bundle 40 and the second tube bundle 50.

[0040] For details, please refer to Figure 2 and Figure 4 When the heat exchange tube bundle includes two sets of tube bundles, the heat exchange inlet 131 and the heat exchange outlet 132 are both located on the end cover 13 at any end of the shell 10 in the length direction. A partition 133 is provided, and the end cover 13 where the partition 133 is located and the end cover 13 where the heat exchange inlet 131 and the heat exchange outlet 132 are located are the same end cover 13.

Claims

1. A shell and tube evaporator characterized by, include: The housing has a refrigerant inlet and a refrigerant outlet, and a heat exchange tube bundle is provided inside the housing. The heat exchange tube bundle includes at least two sets of tube bundles, and multiple sets of tube bundles are arranged sequentially along the flow direction of the refrigerant liquid. The distribution assembly includes a distribution plate, which is closer to the refrigerant inlet than the heat exchange tube bundle. The distribution plate has distribution holes, and a cavity is formed between the distribution plate and the shell. The cavity is filled with a filler, and the proportion of the filler occupying the cavity volume is adapted to the flow distribution of the refrigerant liquid along the length of the distribution plate.

2. The shell-and-tube evaporator according to claim 1, characterized in that: The distribution assembly also includes at least one equalization plate located between two adjacent tube bundles, and the equalization plate has multiple flow equalization holes.

3. The shell-and-tube evaporator according to claim 2, characterized in that: The heat exchange tube bundle includes two sets of tube bundles, namely a first tube bundle and a second tube bundle. The first tube bundle is closer to the refrigerant inlet than the second tube bundle. An equalization plate is provided and is located between the first tube bundle and the second tube bundle.

4. The shell-and-tube evaporator according to claim 2, characterized in that: The heat exchange tube bundle includes three sets of tube bundles, namely a first tube bundle, a second tube bundle, and a third tube bundle. The first tube bundle, the second tube bundle, and the third tube bundle are arranged sequentially along the refrigerant liquid flow direction, and the first tube bundle is closer to the refrigerant inlet than the third tube bundle. There are two equalization plates, which are located between the first tube bundle and the second tube bundle, and between the second tube bundle and the third tube bundle, respectively.

5. The shell-and-tube evaporator according to claim 3 or 4, characterized in that: The length of the distribution plate is the same as the length of the shell.

6. The shell-and-tube evaporator according to claim 5, characterized in that: The refrigerant inlet is located at the middle of the shell along its length.

7. The shell-and-tube evaporator according to claim 6, characterized in that: The diameter of the flow equalization orifice is 5mm-10mm.

8. The shell-and-tube evaporator according to claim 7, characterized in that: The total cross-sectional area of ​​the flow equalization holes is 60%-80% of the cross-sectional area of ​​the equalization plate.

9. The shell-and-tube evaporator according to claim 8, characterized in that: The gap between the first tube bundle and the distribution plate is 1mm-3mm.

10. The shell-and-tube evaporator according to claim 9, characterized in that: A filler material 2 is provided between the heat exchange tube bundle and the shell.

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