CN111947495A

CN111947495A - Heat exchange tube and air conditioner

Info

Publication number: CN111947495A
Application number: CN202010852160.4A
Authority: CN
Inventors: 张治平; 王小勇; 胡东兵; 胡海利
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2020-08-21
Filing date: 2020-08-21
Publication date: 2020-11-17

Abstract

The application provides a heat exchange tube and an air conditioner. The heat exchange tube includes a tube body and a plurality of fins disposed on an outer side of the tube body. The plurality of fins comprise a first fin, a second fin and a third fin, a first boss is formed on the first fin, a second boss is formed on the second fin, and a third boss is formed on the third fin. The height of the third fin is greater than that of the second fin, the height of the second fin is greater than that of the first fin, the third boss is higher than the second boss, and the second boss is higher than the first boss. By applying the technical scheme of the invention, in the falling film process with larger flow, when liquid refrigerant is dripped to the surface of the heat exchange tube, the refrigerant is shunted for three times under the action of the three layers of bosses, so that the refrigerant finally reaching the cavity at the outer side of the tube body is smaller, the accumulation thickness of a liquid film is smaller, the evaporation thermal resistance is reduced by the smaller film thickness, the evaporation phase change rate of the refrigerant is accelerated, and the heat exchange is enhanced.

Description

Heat exchange tube and air conditioner

Technical Field

The invention relates to the technical field of air conditioners, in particular to a heat exchange tube and an air conditioner.

Background

In a central air-conditioning heat exchanger, the falling film evaporator is more and more widely used because of the advantages of high heat exchange efficiency, small refrigerant filling amount, convenient oil return and the like. Meanwhile, under the background of the times of energy conservation and emission reduction and updating of refrigerants, refrigerants with low-temperature chamber effect, such as R1233zd (E), can completely replace the traditional R134a refrigerants in the next ten to twenty years. When the unit price of the R1233zd (E) refrigerant is nearly ten times that of the conventional R134a refrigerant, the use of a falling film evaporator capable of reducing the refrigerant consumption is inevitably selected.

In the falling film evaporator, the falling film evaporation tube is used as a key heat exchange element, and the heat exchange performance of the falling film evaporator is determined to a great extent. In the horizontal falling film evaporator, falling film evaporation tubes are arranged in a horizontal row, and a refrigerant is dripped and sprayed onto the surfaces of the falling film evaporation tubes after being uniformly liquid by a liquid distributor and other structures. The surface of the falling film evaporation tube is of a porous structure formed by extruding fins, so that the refrigerant can be quickly evaporated by a thin film. Meanwhile, the fin top is generally provided with a liquid-homogenizing structure such as a groove or a boss, so that the refrigerant is rapidly spread out and expanded on the surface of the fin top, and the surface dry burning of the falling film evaporation tube and the waste of heat exchange area are avoided.

The special working mode of the falling film evaporation tube enables the heat exchange performance of the falling film evaporation tube under the working condition of small flow and small heat flux density to be more advantageous than that of a flooded evaporation tube. However, under the condition of larger refrigerant flow, along with the gradual increase of the refrigerant flow outside the pipe, the refrigerant quantity which can be used for evaporation and heat exchange in the porous structure of the heat exchange pipe is also increased, so the heat transfer coefficient at the stage is gradually increased. But because the porous structure size is limited, the refrigerant volume that it can hold has the upper limit, and the refrigerant flow that increases again can not participate in the evaporation heat transfer this moment, only can the heat exchange tube surface flow down for falling liquid film evaporating pipe performance can't continue to promote under this operating mode.

Disclosure of Invention

The embodiment of the invention provides a heat exchange tube and an air conditioner, and aims to solve the technical problem that the heat exchange tube in the prior art is limited in refrigerant evaporation efficiency.

The embodiment of the application provides a heat exchange tube, including body and a plurality of fins of setting on the body outside, a plurality of fins include: the first fin is provided with a first boss; the second fin is provided with a second boss; a third fin, wherein a third boss is formed on the third fin; the height of the third fin is greater than that of the second fin, the height of the second fin is greater than that of the first fin, the third boss is higher than the second boss, and the second boss is higher than the first boss.

In one embodiment, the first fin, the second fin, and the third fin are arranged in series.

In one embodiment, two second fins are provided on each of the left and right sides of the first fin, and two third fins are provided on each of the left and right sides of the two second fins.

In one embodiment, the first boss is formed with first grooves for distributing the refrigerant on the first boss to both sides of the first fin.

In one embodiment, the second boss has a second groove formed thereon, and the second groove is used for distributing the refrigerant on the second boss to both sides of the second fin.

In one embodiment, the third boss has a third groove formed therein, and the third groove is used for distributing the refrigerant on the third boss to both sides of the third fin.

In one embodiment, the open end of the third groove is located above the second land and/or the open end of the second groove is located above the first land.

In one embodiment, the first groove and/or the second groove and/or the third groove is a cross-shaped groove.

In one embodiment, the first bosses are distributed along the length direction of the first fins, the second bosses are distributed along the length direction of the second fins, the third bosses are distributed along the length direction of the third fins, and the first bosses, the second bosses and the third bosses are arranged in a staggered mode.

In one embodiment, the first boss and/or the second boss and/or the third boss is elliptical, circular, polygonal, or curved.

In one embodiment, the surface area of the third bosses is greater than the surface area of the second bosses, which are greater than the surface area of the first bosses.

In one embodiment, the third fin has a width greater than a width of the second fin, the second fin having a width greater than a width of the first fin.

In one embodiment, the first fin is provided with a first connecting groove, and the first connecting groove is communicated with two sides of the first fin; and/or the second fin is provided with a second communicating groove which is communicated with two sides of the second fin; and/or the third fin is provided with a third communicating groove which is communicated with two sides of the third fin.

In one embodiment, the heat exchange tube further comprises an inner rib disposed inside the tube body.

In one embodiment, the first projection is arranged obliquely with respect to the horizontal direction, and/or the second projection is arranged obliquely with respect to the horizontal direction, and/or the third projection is arranged obliquely with respect to the horizontal direction.

In one embodiment, the third boss is inclined towards the second boss to distribute the refrigerant on the third boss to the second boss; and/or the second boss inclines towards the first boss so as to distribute the refrigerant on the second boss to the first boss; and/or the first boss is inclined towards the tube body so as to distribute the refrigerant on the first boss to the tube body.

The embodiment of the application provides an air conditioner, which comprises the heat exchange pipe.

In the above embodiment, the first boss is formed on the first fin, the second boss is formed on the second fin, and the third boss is formed on the third fin, so that the heat exchange area of the outer tube of the heat exchange tube is increased, and the evaporation phase change heat exchange is strengthened. Meanwhile, as the first boss, the second boss and the third boss are the same in height, in the process of falling film with large flow, when liquid refrigerant is dripped to the surface of the heat exchange tube, the refrigerant is shunted for three times under the action of the three layers of bosses, so that the refrigerant finally reaching the cavity at the outer side of the tube body is smaller, the accumulation thickness of a liquid film is smaller, the evaporation thermal resistance is reduced due to the smaller film thickness, the evaporation phase change rate of the refrigerant is accelerated, and the heat exchange is strengthened. When the refrigerant flow continuously increases, the refrigerant can be gradually filled in the cavity at the outer side of the pipe body covering the two layers of lower parts. At the moment, the fins soaked in the refrigerant can provide a large amount of vaporization cores so as to strengthen evaporation heat exchange; meanwhile, the bubbles greatly disturb the liquid refrigerant due to the existence of the lower two layers of fins in the rising process, and evaporation phase change heat exchange is further enhanced.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic perspective view of an embodiment of a heat exchange tube according to the present invention;

FIG. 2 is a schematic top view of the heat exchange tube of FIG. 1;

fig. 3 is a schematic cross-sectional view of the heat exchange tube of fig. 1.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the following embodiments and accompanying drawings. The exemplary embodiments and descriptions of the present invention are provided to explain the present invention, but not to limit the present invention.

Fig. 1 and 3 show an embodiment of the heat exchange tube of the present invention comprising a tube body 40 and a plurality of fins provided on the outside of the tube body 40. The plurality of fins include a first fin 10, a second fin 20, and a third fin 30, the first fin 10 is formed with a first boss 11, the second fin 20 is formed with a second boss 21, and the third fin 30 is formed with a third boss 31. The height of the third fin 30 is greater than that of the second fin 20, the height of the second fin 20 is greater than that of the first fin 10, the third boss 31 is higher than the second boss 21, and the second boss 21 is higher than the first boss 11.

By applying the technical scheme of the invention, the first boss 11 is formed on the first fin 10, the second boss 21 is formed on the second fin 20, and the third boss 31 is formed on the third fin 30, so that the heat exchange area of the outer tube of the heat exchange tube is increased, and the evaporation phase change heat exchange is strengthened. Meanwhile, due to the fact that the heights of the first boss 11, the second boss 21 and the third boss 31 are different, in the falling film process with large flow, when liquid refrigerants are dripped to the surface of the heat exchange tube, the refrigerants are shunted for three times under the action of the three layers of bosses, so that the refrigerants which finally reach the cavity at the outer side of the tube body 40 are few, the accumulation thickness of liquid films is small, the evaporation thermal resistance is reduced due to the small film thickness, the evaporation phase change rate of the refrigerants is accelerated, and the heat exchange is strengthened. When the flow of the refrigerant is continuously increased, the refrigerant is gradually filled in the cavity covering the outer sides of the two lower layers of the tube body 40. At the moment, the fins soaked in the refrigerant can provide a large amount of vaporization cores so as to strengthen evaporation heat exchange; meanwhile, in the rising process of the bubbles, due to the existence of the lower two layers of fins, disturbance of the bubbles to the liquid refrigerant is greatly increased, and evaporation phase change heat exchange is further enhanced.

In a preferred embodiment, in the present embodiment, the first fin 10, the second fin 20, and the third fin 30 are arranged in sequence. Therefore, the refrigerant can be continuously divided for three times, the accumulation thickness of the liquid film is reduced as much as possible, and heat exchange and evaporation are facilitated. As shown in fig. 3, as a more preferred embodiment, two second fins 20 are provided on both left and right sides of the first fin 10, respectively, and two third fins 30 are provided on both left and right sides of the two second fins 20, respectively. Therefore, the function of gradually collecting the refrigerant to the cavity at the outer side of the pipe body 40 can be achieved, and the evaporation of the refrigerant in the evaporation cavity is facilitated.

As shown in fig. 1 and 2, in the solution of the present embodiment, a first groove 111 is formed on the first boss 11, and the first groove 111 is used for distributing the refrigerant on the first boss 11 to both sides of the first fin 10. The second boss 21 is formed with a second groove 211, and the second groove 211 is used for distributing the refrigerant on the second boss 21 to both sides of the second fin 20. The third bosses 31 are formed with third grooves 311, and the third grooves 311 distribute the refrigerant on the third bosses 31 to both sides of the third fins 30. Like this, just can play more reasonable distribution drainage effect to the refrigerant with the help of the slot on each layer boss, the refrigerant except can be in the quick extension in the body 40 outside, the slot on the boss of two-layer lower can be directionally quick to the cavity fluid infusion of body 40 outside department to make the evaporation continuously high-efficiently go on. More preferably, the open end of the third groove 311 is located above the second boss 21, and the open end of the second groove 211 is located above the first boss 11. Therefore, the refrigerant can be directly guided to the bosses from high to low in sequence, and the bosses are facilitated to receive the refrigerant. As shown in fig. 2, in the solution of the present embodiment, the first trench 111, the second trench 211, and the third trench 311 are cross-shaped trenches. As other alternative embodiments, it is also possible that the first trench 111, the second trench 211, and the third trench 311 are in-line trenches.

As other alternative embodiments, it is possible to form the first grooves 111 only on the first lands 11. Alternatively, it is also possible to form the second grooves 211 only on the second lands 21. Alternatively, it is also possible to form the third grooves 311 only on the third bosses 31.

Preferably, in the technical solution of this embodiment, the first bosses 11 are distributed along the length direction of the first fins 10, the second bosses 21 are distributed along the length direction of the second fins 20, the third bosses 31 are distributed along the length direction of the third fins 30, and the first bosses 11, the second bosses 21, and the third bosses 31 are arranged in a staggered manner, which helps the refrigerant to fall on each layer of bosses.

Optionally, in the technical solution of this embodiment, the first boss 11, the second boss 21, and the third boss 31 are oval. As other alternative embodiments, the first boss 11, the second boss 21 and the third boss 31 may also be circular, polygonal or curved, wherein the polygonal shape is preferably a diamond shape or a regular hexagon shape.

As shown in fig. 2, in the solution of the present embodiment, the surface area of the third boss 31 is larger than the surface area of the second boss 21, and the surface area of the second boss 21 is larger than the surface area of the first boss 11. Thus, the third boss 31 receives the most refrigerant, and the refrigerant can descend layer by layer. Correspondingly, in this embodiment, the width of the third fin 30 is greater than that of the second fin 20, the width of the second fin 20 is greater than that of the first fin 10, the third bosses 31 are higher than the second bosses 21, and the second bosses 21 are higher than the first bosses 11.

As shown in fig. 1, in the technical solution of this embodiment, a first connecting groove 12 is formed on a first fin 10, and the first connecting groove 12 communicates two sides of the first fin 10; the second fin 20 is provided with a second communicating groove 22, and the second communicating groove 22 is communicated with two sides of the second fin 20; the third fin 30 is provided with a third communicating groove 32, and the third communicating groove 32 communicates with both sides of the third fin 30. This contributes to the circulation of the refrigerant twice through each fin, and improves the circulation of the refrigerant outside the tube 40. As other alternative embodiments, it is also possible to provide only the first connecting groove 12 in the first fin 10, or to provide only the second connecting groove 22 in the second fin 20. Alternatively, the third communication groove 32 may be formed only in the third fin 30.

As shown in fig. 1, in the solution of the present embodiment, the heat exchange tube further includes an inner rib 41 provided inside the tube body 40. The heat exchange area in the pipe body 40 is increased through the inner ribs 41, the local fluid turbulence effect is enhanced, and the non-phase change heat exchange in the pipe body 40 is enhanced.

Optionally, in the technical solution of this embodiment, a plurality of fins are spirally wound on the outer side of the tube body 40, and the inner ribs 41 are spirally distributed on the inner side of the tube body 40.

The horizontal direction is shown in fig. 3, and the horizontal direction only represents the horizontal direction after the heat exchange pipe is horizontally installed, and does not limit the structure of the present invention. The invention also provides an embodiment different from the embodiment shown in fig. 3, in the embodiment, the first boss 11 is obliquely arranged relative to the horizontal direction, the second boss 21 is obliquely arranged relative to the horizontal direction, the third boss 31 is obliquely arranged relative to the horizontal direction, and the oblique arrangement of the first boss 11, the second boss 21 and the third boss 31 relative to the horizontal direction is beneficial to discharging the refrigerant on the first boss 11, the second boss 21 and the third boss 31 in time, so that the phenomenon that the liquid film on the bosses is accumulated to be too thick to influence heat exchange is avoided. As other alternative embodiments, it is also possible to arrange only any one or two of the first boss 11, the second boss 21, and the third boss 31 to be inclined with respect to the horizontal direction.

More preferably, in the above embodiment, the third boss 31 is inclined toward the second boss 21 to distribute the refrigerant on the third boss 31 to the second boss 21, the second boss 21 is inclined toward the first boss 11 to distribute the refrigerant on the second boss 21 to the first boss 11, and the first boss 11 is inclined toward the pipe body 40 to distribute the refrigerant on the first boss 11 to the pipe body 40, so as to facilitate the refrigerant to fall on the boss and the pipe body 40. As other alternative embodiments, it is also possible to incline only the third boss 31 toward the second boss 21 to distribute the refrigerant on the third boss 31 to the second boss 21 or incline only the second boss 21 toward the first boss 11 to distribute the refrigerant on the second boss 21 to the first boss 11.

The invention also provides an air conditioner adopting the heat exchange tube. The air conditioner is helpful for improving the heat exchange efficiency of the air conditioner, and further improving the refrigeration efficiency of the air conditioner.

Take a falling film evaporation tube with an outer diameter of 19.05mm and an inner diameter of 16.2mm as an example. The heights H1, H2 and H3 of the third fins 30, the second fins 20 and the first fins 10 are respectively 0.5-1.0 mm, 0.3-0.8 mm and 0.1-0.6 mm, and preferably 0.8mm, 0.5mm and 0.3mm respectively.

The widths H4, H5 and H6 of the third boss 31, the second boss 21 and the first boss 11 are respectively 0.05-0.0.35 times of the width of the corresponding fin, and the preferred values are respectively 0.3mm, 0.2mm and 0.15 mm.

The depths H7, H8 and H9 of the third grooves 311, the second grooves 211 and the first grooves 111 on the third bosses 31, the second bosses 21 and the first bosses 11 are respectively 0.1-0.8 times of the width of the corresponding bosses, and the optimal values are respectively 0.2mm, 0.1mm and 0.08 mm. The axial widths L4, L5 and L6 of the third fin 30, the second fin 20 and the first fin 10 are respectively 0.3-0.8 mm, 0.2-0.5 mm and 0.1-0.3 mm, and are respectively preferably 0.5mm, 0.4mm and 0.2 mm. The axial widths L1, L2 and L3 of the third boss 31, the second boss 21 and the first boss 11 are respectively 0.2-0.6 times of the axial width of the corresponding outer fin column, and the optimal values are respectively 0.25mm, 0.25mm and 0.1 mm.

The number of the third fins 30, the second fins 20 and the first fins 10 is 20 to 40, 40 to 80, 20 to 40, preferably 30, 60, 30. It should be noted that, in order to enable the fins to be processed normally, the FPI number of the second fin 20 needs to be 2 times that of the third fin 30 and the first fin 10, and the FPI numbers of the third fin 30 and the first fin 10 are the same. Here, the FPI number means the number of fins per inch.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes may be made to the embodiment of the present invention by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A heat exchange tube comprising a tube body (40) and a plurality of fins provided on the outside of the tube body (40), characterized in that the plurality of fins comprises:

a first fin (10), wherein a first boss (11) is formed on the first fin (10);

a second fin (20), wherein a second boss (21) is formed on the second fin (20);

a third fin (30), wherein a third boss (31) is formed on the third fin (30);

the height of the third fin (30) is greater than that of the second fin (20), the height of the second fin (20) is greater than that of the first fin (10), the third boss (31) is higher than the second boss (21), and the second boss (21) is higher than the first boss (11).

2. The heat exchange tube according to claim 1, wherein the first fin (10), the second fin (20) and the third fin (30) are arranged in sequence.

3. The heat exchange tube according to claim 2, wherein the first fin (10) is provided at both left and right sides thereof with two of the second fins (20), respectively, and the two second fins (20) are provided at both left and right sides thereof with two of the third fins (30), respectively.

4. The heat exchange tube according to claim 1, wherein the first bosses (11) are formed with first grooves (111), and the first grooves (111) are used for distributing the refrigerant on the first bosses (11) to two sides of the first fins (10).

5. The heat exchange tube of claim 4, wherein the second bosses (21) are formed with second grooves (211), and the second grooves (211) are used for distributing the refrigerant on the second bosses (21) to two sides of the second fins (20).

6. The heat exchange tube according to claim 5, wherein the third bosses (31) are formed with third grooves (311), and the third grooves (311) are used for distributing the refrigerant on the third bosses (31) to two sides of the third fins (30).

7. A heat exchange tube according to claim 6, characterised in that the open end of the third groove (311) is located above the second boss (21) and/or the open end of the second groove (211) is located above the first boss (11).

8. A heat exchange tube according to claim 6, characterized in that the first grooves (111) and/or the second grooves (211) and/or the third grooves (311) are cross-shaped grooves.

9. The heat exchange tube according to claim 1, wherein the first bosses (11) are distributed along the length direction of the first fin (10), the second bosses (21) are distributed along the length direction of the second fin (20), the third bosses (31) are distributed along the length direction of the third fin (30), and the first bosses (11), the second bosses (21) and the third bosses (31) are arranged in a staggered manner.

10. A heat exchange tube according to claim 1, characterized in that the first bosses (11) and/or the second bosses (21) and/or the third bosses (31) are oval, circular, polygonal or curved.

11. A heat exchange tube according to claim 1, wherein the surface area of the third bosses (31) is larger than the surface area of the second bosses (21), and the surface area of the second bosses (21) is larger than the surface area of the first bosses (11).

12. The heat exchange tube according to claim 1, wherein the width of the third fin (30) is greater than the width of the second fin (20), and the width of the second fin (20) is greater than the width of the first fin (10).

13. The heat exchange tube according to claim 1, wherein the first fin (10) is provided with a first connecting groove (12), and the first connecting groove (12) is communicated with two sides of the first fin (10);

and/or a second communicating groove (22) is formed in the second fin (20), and the second communicating groove (22) is communicated with two sides of the second fin (20);

and/or a third communicating groove (32) is formed in the third fin (30), and the third communicating groove (32) is communicated with two sides of the third fin (30).

14. A heat exchange tube according to claim 1, further comprising an inner rib (41) provided inside the tube body (40).

15. A heat exchange tube according to claim 1, characterized in that the first bosses (11) are arranged obliquely with respect to the horizontal direction, and/or the second bosses (21) are arranged obliquely with respect to the horizontal direction, and/or the third bosses (31) are arranged obliquely with respect to the horizontal direction.

16. The heat exchange tube according to claim 15, wherein the third bosses (31) are inclined toward the second bosses (21) to distribute the refrigerant on the third bosses (31) to the second bosses (21);

and/or the second boss (21) is inclined towards the first boss (11) so as to distribute the refrigerant on the second boss (21) to the first boss (11);

and/or the first boss (11) is inclined towards the pipe body (40) so as to distribute the refrigerant on the first boss (11) to the pipe body (40).

17. An air conditioner comprising a heat exchange tube, wherein the heat exchange tube is the heat exchange tube of any one of claims 1 to 16.