A refrigerant distribution structure of a falling film evaporator

Abstract

The present invention relates to a refrigerant distribution structure of a falling film evaporator, which includes a distribution box. The distribution box is in the shape of a rectangular box, and its bottom plate is provided with a plurality of first through holes, and its top plate is provided with an exhaust hole and a refrigerant inlet pipe; gas-liquid separation structures are provided on both sides of the distribution box; a liquid blocking structure connected to the distribution box is provided below the gas-liquid separation structure; the distribution box is arranged in the upper part of the falling film evaporator, so that all the heat exchange tubes of the falling film evaporator are located below the distribution box, and the distribution box is close to the heat exchange tubes; the liquid blocking structure is located outside the heat exchange tubes. The present invention has reasonable design, simple structure and convenient use. After the refrigerant enters the falling film evaporator, it can be more evenly distributed, improving the heat exchange efficiency. At the same time, the gas-liquid separation of the refrigerant can be more complete, avoiding excessive liquid refrigerant from being sucked into the compressor, and improving the reliability of the compressor and the stability of the system.

Description

Technical Field

[0001] The present invention relates to an air-conditioning component, in particular to a component of a falling film evaporator, specifically a refrigerant distribution structure of a falling film evaporator. Background Art

[0002] According to the HFCs refrigerant reduction schedule set by the Kigali Amendment, developed countries have begun to reduce the use of HFCs refrigerants, and China will reduce or freeze the use of HFCs refrigerants by air-conditioning manufacturers in 2024. Due to the high cost of new environmentally friendly refrigerants, falling film evaporators are currently widely used. The falling film evaporator has the characteristics of less refrigerant charge and good heat transfer performance. However, when the existing falling film evaporator works, after the refrigerant enters the evaporator, it naturally flows down from top to bottom onto the heat exchange tube bundle and evaporates after heat exchange. During this period, the refrigerant distribution is prone to be uneven, resulting in the phenomenon of dryness in some heat exchange tubes, affecting the heat transfer efficiency. At the same time, it is also easy for too much liquid refrigerant to flow into the compressor along with the gaseous refrigerant, affecting the reliability of the compressor and the stability of the system. Therefore, it is necessary to improve the distribution of the refrigerant to improve the heat transfer efficiency. Summary of the Invention

[0003] The purpose of the present invention is to provide a refrigerant distribution structure for a falling film evaporator in view of the deficiencies of the prior art, which can make the refrigerant distribution more uniform and improve the heat transfer efficiency. At the same time, it can also prevent too much liquid refrigerant from being sucked into the compressor, improving the reliability of the compressor and the stability of the system.

[0004] The technical solution of the present invention is as follows:

[0005] A refrigerant distribution structure for a falling film evaporator includes a distribution box, which is in the shape of a rectangular box. Its bottom plate is provided with a plurality of first through holes, and its top plate is provided with an exhaust hole and a refrigerant inlet pipe; gas-liquid separation structures are provided on both sides of the distribution box; a liquid blocking structure connected to the distribution box is provided below the gas-liquid separation structure; the distribution box is arranged in the upper part of the falling film evaporator, so that all the heat exchange tube bundles of the falling film evaporator are located below the distribution box; the liquid blocking structure is located outside the heat exchange tube bundle.

[0006] Further, the cross-section of the top plate is trapezoidal.

[0007] Further, the gas-liquid separation structure includes an upper plate and a lower plate; both the upper plate and the lower plate are strip-shaped, and their lengths are equivalent to that of the distribution box; the upper plate is located above the lower plate and is arranged parallel to each other; one side edge of the upper plate and the lower plate is respectively connected to the side wall of the distribution box; a number of longitudinally arranged partition plates are provided between the upper plate and the lower plate, dividing its interior into at least two cavities; a plurality of third through holes are provided on the upper bottom and the lower bottom of each cavity.

[0008] Further, the partition plates are parallel to each other, so that the cross-section of the gas-liquid separation structure is a plurality of parallelograms.

[0009] Further, the liquid blocking structure includes two liquid blocking plates; each liquid blocking plate is in the shape of a long strip and is disposed on both sides of the distribution box. Its upper end is connected to the side wall of the distribution box, and its lower end is provided with an upturned hook; the height of the liquid blocking plate is greater than the diameter of a single heat exchange tube; the hook faces the heat exchange tube bundle.

[0010] Further, an internal distribution structure is further included. The internal distribution structure includes a first distribution layer and a second distribution layer; the first distribution layer is in the shape of a hollow box with open ends, and a plurality of second through holes are provided on its upper bottom, and a protruding flange is provided on its lower bottom; there are two second distribution layers, both of which are strip-shaped wire mesh structures or foam metal structures, and their lengths are equivalent to that of the first distribution layer; the second distribution layers are arranged longitudinally along the distribution box, its upper end is connected to the top plate, and its lower end is connected to the flange; the upper bottom of the first distribution layer is communicated with the refrigerant inlet pipe.

[0011] Advantages of the present invention:

[0012] The present invention is reasonably designed, simple in structure and convenient to use. After the refrigerant enters the falling film evaporator, it can be more evenly distributed, improving the heat exchange efficiency. At the same time, the gas-liquid separation of the refrigerant can be more complete, avoiding excessive liquid refrigerant being sucked into the compressor, and improving the reliability of the compressor and the stability of the system. Description of the drawings

[0013] Figure 1 is an exploded schematic view of the present invention.

[0014] Figure 2 is a schematic view of the present invention installed in a falling film evaporator.

[0015] Figure 3 is Figure 2 an enlarged schematic view of A in

[0016] Figure 4 a schematic view of the left liquid blocking plate.

[0017] Wherein: 1-top plate; 2-second distribution layer; 3-gas-liquid separation structure; 4-liquid blocking plate; 5-bottom plate; 6-first distribution layer; 7-refrigerant inlet pipe; 8-outlet pipe; 9-heat exchange tube bundle; 10-cylinder body; 11-distribution box; 12-exhaust hole; 31-upper plate; 32-lower plate; 33-partition plate. Specific embodiments

[0018] The present invention will be further described below with reference to the drawings and embodiments.

[0019] As Figures 1 to 4 shown.

[0020] A refrigerant distribution structure of a falling film evaporator, including a distribution box 11. The distribution box 11 is in the shape of a rectangular box, and its bottom plate 5 is provided with a plurality of first through holes, and its top plate 1 is provided with an exhaust hole 12 and a refrigerant inlet pipe 7. The distribution box 11 is arranged in the upper part of the cylinder body 10 of the falling film evaporator, so that all the heat exchange tubes 9 of the falling film evaporator are located below the distribution box 11, and the distribution box 11 is close to the mixed heat tubes 9. The refrigerant inlet pipe 7 penetrates through the cylinder body 10 of the falling film evaporator and is connected to the circulation pipeline of the air conditioner. After the gas-liquid mixed refrigerant in the circulation pipeline enters the distribution box 11, the gaseous refrigerant therein can be discharged from the distribution box 11 through the exhaust hole 12 and enter the cylinder body 10, and the liquid refrigerant drops onto the heat exchange tubes 9 through the through holes on the bottom plate 5 and evaporates through heat exchange. Then, the gaseous refrigerant in the cylinder body 10 can be discharged through the air outlet pipe 8 arranged on the cylinder body and then inhaled into the compressor through the circulation pipeline of the air conditioner. Preferably, the cross section of the top plate 1 is trapezoidal, which can increase its internal space and adapt to the shape of the cylinder body 10.

[0021] An internal distribution structure is also provided in the distribution box 11. The internal distribution structure includes a first distribution layer 6 and a second distribution layer 2. The first distribution layer 6 is in the shape of a hollow box with both ends open, its upper bottom is provided with a plurality of second through holes, and its lower bottom is provided with an outwardly convex flange. The second distribution layer 2 has two, both of which are strip-shaped wire mesh structures or foam metal structures, and their lengths are equivalent to that of the first distribution layer 6. The second distribution layer 2 is arranged longitudinally along the distribution box 11, its upper end is connected to the top plate 1, and its lower end is connected to the flange. The upper bottom of the first distribution layer is communicated with the refrigerant inlet pipe 7, so that the refrigerant can first enter the first distribution layer 6 and be discharged from the second through holes on its upper bottom. Thus, the refrigerant can be evenly distributed in the longitudinal direction by using the action of gravity and the porous channels. Then, it is discharged from the second distribution layer 2 into the distribution box 11, and during the discharge process, the gas-liquid separation of the gas-liquid mixed refrigerant is carried out through the porous structure of the wire mesh or foam metal. Preferably, the shape of the second through hole is circular or square. When it is circular, its diameter is 2 - 10 mm; when it is square, its size is 2×2 mm - 10×10 mm. The thickness of the second distribution layer 2 is 10 - 30 mm.

[0022] On both sides of the distribution box 11, there is also provided a gas-liquid separation structure 3. The gas-liquid separation structure 3 includes an upper plate 31 and a lower plate 32. Both the upper plate 31 and the lower plate 32 are strip-shaped, arranged parallel to each other vertically, and there are a number of partition plates 33 between them. The partition plates 33 are arranged vertically, and their upper and lower ends are respectively connected to the upper plate 31 and the lower plate 32, partitioning at least two cavities between the upper plate 31 and the lower plate 32. On the upper plate 31 and the lower plate 32 of each cavity, there are respectively provided third through-holes arranged in a row. The length of the gas-liquid separation structure 3 is equivalent to that of the distribution box 11, and one side of the upper plate 31 and the lower plate 32 is fixed on the side wall of the distribution box 11. The width of the upper plate 31 is adapted to the inner diameter of the cylinder 10, so that the gap between it and the inner wall of the cylinder 10 is equivalent to the aperture of the third through-hole. Preferably, the partition plates 33 are parallel to each other and inclined at a certain angle, so that their cross-sections are multiple parallelograms. After the refrigerant that has not been separated in the cylinder enters the gas-liquid separation structure, the gas-liquid two-phase can be separated again. Thus, the gaseous refrigerant can be discharged from the third through-holes on the upper plate 31 and enter the upper part of the cylinder 10, and then be discharged from the cylinder 10 through the outlet pipe 8 and enter the circulation pipeline. At the same time, the separated liquid refrigerant can be collected on the lower plate and flow into the lower part of the cylinder 10 through the third through-holes on the lower plate to continue participating in the heat exchange operation.

[0023] Below the gas-liquid separation structure 3, there is provided a liquid blocking structure connected to the distribution box 11. The liquid blocking structure includes two liquid blocking plates 4. Each liquid blocking plate 4 is in the shape of a long strip plate, placed on both sides of the distribution box 11 respectively. Its upper end is connected to the side wall of the distribution box 11, and its lower end is suspended outside the heat exchange tube bundle 9. The height of the liquid blocking plate 4 is greater than the diameter of a single heat exchange tube, so that it can block at least the uppermost heat exchange tube bundle 9 to prevent the liquid refrigerant splashed from the uppermost heat exchange tube from mixing into the gaseous refrigerant and being sucked into the compressor. The lower end of the liquid blocking plate is provided with an upturned hook, and the hook faces the heat exchange tube bundle to collect the blocked liquid refrigerant in the hook. Preferably, the height of the liquid blocking plate is 15 - 150 mm. The angle a of the hook is 45 - 135°.

[0024] By setting structures such as the distribution box, the present invention can make the refrigerant more evenly distributed after entering the falling film evaporator, improving the heat exchange efficiency. At the same time, by setting the internal distribution structure and the gas-liquid separation structure, the gas-liquid separation of the refrigerant can be more complete, avoiding excessive liquid refrigerant from being sucked into the compressor, and improving the reliability of the compressor and the stability of the system.

[0025] Parts not involved in the present invention are the same as or can be implemented by using the prior art.

Claims

1. A refrigerant distribution structure of a falling film evaporator, including a distribution box, characterized in that: The distribution box is in the shape of a rectangular box. Its bottom plate is provided with a plurality of first through holes, and its top plate is provided with an exhaust hole and a refrigerant inlet pipe; both sides of the distribution box are provided with gas-liquid separation structures; a liquid blocking structure connected to the distribution box is provided below the gas-liquid separation structure; the distribution box is arranged in the upper part of the falling film evaporator, so that all the heat exchange tubes of the falling film evaporator are located below the distribution box; The liquid blocking structure is located outside the heat exchange tubes; an internal distribution structure is arranged in the distribution box, and the internal distribution structure includes a first distribution layer and a second distribution layer; the first distribution layer is in the shape of a hollow box, open at both ends along the length direction, its upper bottom is provided with a plurality of second through holes, and its lower bottom is provided with an outwardly convex flange; there are two second distribution layers, both of which are strip-shaped wire mesh structures or foam metal structures, and their lengths are equivalent to that of the first distribution layer; the second distribution layers are arranged longitudinally along the distribution box, its upper end is connected to the top plate, and its lower end is connected to the flange; the upper bottom of the first distribution layer is connected and communicated with the refrigerant inlet pipe; the upper bottom of the first distribution layer is connected and communicated with the refrigerant inlet pipe. The refrigerant first enters the first distribution layer and is discharged from the second through holes on the upper bottom of the first distribution layer. By using the action of gravity and the porous channels, the refrigerant is evenly distributed in the longitudinal direction and then discharged from the second distribution layer into the distribution box; The gas-liquid separation structure includes an upper plate and a lower plate; both the upper plate and the lower plate are strip-shaped, and their lengths are equivalent to that of the distribution box; The upper plate is located above the lower plate and is arranged in parallel; one side edge of the upper plate and the lower plate are respectively connected to the side wall of the distribution box; a plurality of longitudinally arranged partition plates are provided between the upper plate and the lower plate, dividing its interior into at least two cavities; both the upper bottom and the lower bottom of each cavity are provided with a plurality of third through holes.

2. The refrigerant distribution structure of the falling film evaporator according to claim 1, characterized in that: The cross section of the top plate is trapezoidal.

3. The refrigerant distribution structure of the falling film evaporator according to claim 1, characterized in that: The partition plates are parallel to each other, so that the cross section of the gas-liquid separation structure is a plurality of parallelograms.

4. The refrigerant distribution structure of the falling film evaporator according to claim 1, characterized in that: The liquid blocking structure includes two liquid blocking plates; each liquid blocking plate is in the shape of a long strip plate, and is respectively arranged on both sides of the distribution box. Its upper end is connected to the side wall of the distribution box, and its lower end is provided with an upturned hook; the height of the liquid blocking plate is greater than the diameter of a single heat exchange tube; the hook faces the heat exchange tubes.

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