CN115183605A

CN115183605A - Shell and tube heat exchanger and air conditioning unit

Info

Publication number: CN115183605A
Application number: CN202210892514.7A
Authority: CN
Inventors: 王宗信; 胡东兵; 胡海利; 游浩亮
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2022-07-27
Filing date: 2022-07-27
Publication date: 2022-10-14
Also published as: WO2024021698A1

Abstract

The invention provides a shell and tube heat exchanger and an air conditioning unit. The shell-and-tube heat exchanger comprises a shell, and a flash structure and a liquid separating structure which are arranged in the shell, wherein a refrigerant inlet is formed in the shell, the liquid separating structure is arranged on one side, away from the refrigerant inlet, of the flash structure, and refrigerant entering from the refrigerant inlet flows through the flash structure and the liquid separating structure in sequence. According to the shell-and-tube heat exchanger and the air conditioning unit, the flash structure is arranged in the shell-and-tube heat exchanger, so that the product integration level is improved, the potential safety hazards of pipeline vibration and refrigerant leakage are reduced due to the use of a connecting pipeline, meanwhile, the refrigerant throttled by the flash structure is subjected to gas-liquid separation, the liquid separation uniformity can be improved, the problem of refrigerant splashing caused by the fact that the refrigerant impacts the outside of the heat exchange pipe is solved, the film distribution effect is enhanced, and the heat transfer coefficient is improved.

Description

Shell and tube heat exchanger and air conditioning unit

Technical Field

The invention relates to the technical field of air treatment equipment, in particular to a shell-and-tube heat exchanger and an air conditioning unit.

Background

Besides four main components of a compressor, a condenser, a throttling device and an evaporator, the refrigerating system also needs auxiliary components such as an oil separator, a flash tank, a gas-liquid separator and the like to improve the performance of the unit, and meanwhile, pipelines and electric control equipment are matched to ensure the reliable operation of the unit. In a centrifugal water chilling unit, two-stage compression two-stage throttling and intermediate incomplete cooling refrigeration circulation is usually used, namely, high-temperature and high-pressure refrigerant from a condenser enters a flash evaporator through a first-stage throttling orifice plate to realize gas-liquid separation, gas is supplied between a high-pressure stage compressor and a low-pressure stage compressor, and liquid enters an evaporator through a second-stage throttling orifice plate.

Particularly, compared with a single-stage compression refrigeration cycle, the centrifugal machine adopts a two-stage compression two-stage throttling and incomplete intermediate cooling refrigeration cycle, the capacity and the energy efficiency of a system are improved, the exhaust temperature of a compressor is reduced, and meanwhile, a throttling orifice plate, a flash evaporator and a connecting pipeline piece are also added. On the one hand, the newly added parts increase the manufacturing cost of the unit, the flash tank increases potential safety hazards for the pressure container, and on the other hand, the risk of vibration of the connecting pipeline and leakage of the refrigerant is increased.

Disclosure of Invention

In order to solve the technical problems of vibration of a connecting pipeline, leakage of a refrigerant and the like caused by the complex structure of a refrigerating system in the prior art, a shell and tube heat exchanger and an air conditioning unit are provided, wherein a flash structure and a heat exchange structure are combined to reduce the structural complexity.

A shell and tube heat exchanger comprises a shell, a flash structure and a liquid separating structure, wherein the flash structure and the liquid separating structure are arranged in the shell, a refrigerant inlet is formed in the shell, the liquid separating structure is arranged on one side, away from the refrigerant inlet, of the flash structure, and refrigerants entering the refrigerant inlet sequentially flow through the flash structure and the liquid separating structure.

The flash structure comprises at least two throttle plates, all the throttle plates are arranged in the shell in parallel along the direction far away from the refrigerant inlet, first gas-liquid separation spaces are enclosed by the throttle plate on the uppermost layer and the corresponding shell and between the two adjacent throttle plates and the corresponding shells, and the refrigerant entering from the refrigerant inlet flows through all the first gas-liquid separation spaces in sequence.

One end of each throttle plate is provided with a throttle hole, and the throttle holes of two adjacent throttle plates are arranged in a staggered mode.

All the throttle plates at least comprise a second throttle plate positioned at the lowest layer, an inclined part with an included angle with the horizontal plane is formed on the second throttle plate, and the throttle holes are arranged on the inclined part.

The second throttle plate includes a flat portion and an inclined portion arranged in parallel in a width direction of the second throttle plate, a space through which a refrigerant flows is provided between the flat portion and the adjacent throttle plate, and a space between the inclined portion and the adjacent throttle plate is gradually increased in a direction away from the flat portion.

And the shell is provided with an air supplementing port, and the air supplementing port is communicated with the space.

The flash structure still includes the filtrating board, the filtrating board set up in on the rake, be provided with the filtrating hole on the filtrating board, just filtrating board, part the rake with correspond the casing encloses into the hydrops space jointly, filtrating board, part the rake, adjacent the throttle plate with correspond the casing encloses into first gas-liquid separation space jointly.

The flash structure also comprises a plurality of baffle plates, and all the baffle plates are arranged in the first gas-liquid separation space in a staggered manner.

The liquid separating structure comprises an overflow plate, all the throttle plates comprise a second throttle plate positioned at the lowermost layer, the overflow plate is arranged below the second throttle plate, and a second gas-liquid separating space is enclosed among the overflow plate, the second throttle plate and the corresponding shell.

And the overflowing plate is provided with an overflowing hole, and the overflowing hole and the throttling hole on the second throttling plate are arranged in a staggered mode.

The shell-and-tube heat exchanger comprises a side baffle, the side baffle is positioned below the second throttle plate and on one side of the over-flow plate, the second throttle plate and part of the side baffle enclose the second gas-liquid separation space together on the first side of the side baffle, and the side baffle and the corresponding shell form an exhaust area on the second side of the side baffle.

The side baffle is provided with an air outlet, and the second gas-liquid separation space is communicated with the exhaust area through the air outlet.

And a filtering mechanism is arranged at the air outlet.

The overflowing plate is provided with an overflowing hole, and the air outlet is located above the overflowing hole.

The shell is provided with an air outlet, and an air baffle plate is arranged between the air outlet and the air outlet.

The shell and tube heat exchanger further comprises a plurality of heat exchange tubes, all the heat exchange tubes are arranged below the liquid separating structure, and all the heat exchange tubes are located on the first sides of the side baffles.

The liquid separation structure further comprises at least two liquid separation plates, all the liquid separation plates are arranged below the overflowing plate in parallel, and liquid separation spaces are formed between the uppermost liquid separation plate and the overflowing plate and between two adjacent liquid separation plates.

The liquid separation plates are provided with liquid separation holes, and the liquid separation holes in two adjacent liquid separation plates are arranged in a staggered mode.

The flash structure comprises at least two throttle plates, the liquid separating structure further comprises at least two liquid separating plates, a side sealing plate is connected between the throttle plate on the uppermost layer and the edge of the liquid separating plate on the same side of the liquid separating plate on the lowermost layer, and the side sealing plate and the corresponding part of the shell are arranged in a copying manner.

An air conditioning unit comprises the shell-and-tube heat exchanger.

According to the shell-and-tube heat exchanger and the air conditioning unit, the flash structure is arranged in the shell-and-tube heat exchanger, the product integration level is improved, the potential safety hazards of pipeline vibration and refrigerant leakage are reduced due to the use of the connecting pipeline, meanwhile, the refrigerant throttled by the flash structure is subjected to gas-liquid separation, so that the liquid separation structure can separate liquid refrigerant subjected to gas-liquid separation, the liquid separation uniformity can be improved, the problem of refrigerant splashing caused by the fact that the refrigerant impacts the outside of the heat exchange pipe is solved, the film distribution effect is enhanced, and the heat transfer coefficient is improved.

Drawings

FIG. 1 is a schematic structural diagram of a flash structure and a liquid separation structure according to an embodiment of the present invention;

FIG. 2 is another schematic structural diagram of an embodiment of the present invention;

fig. 3 is a cross-sectional view of a shell and tube heat exchanger in accordance with an embodiment of the present invention;

fig. 4 is another cross-sectional view of a shell and tube heat exchanger in accordance with an embodiment of the present invention;

fig. 5 is another cross-sectional view of a shell and tube heat exchanger in accordance with an embodiment of the present invention;

FIG. 6 is a schematic view of a throttle plate according to an embodiment of the present invention;

FIG. 7 is a schematic illustration of a second throttle plate in accordance with an embodiment of the present invention;

FIG. 8 is a schematic structural view of a filtrate plate according to an embodiment of the present invention;

FIG. 9 is a schematic structural view of an embodiment of an overflow plate of the present invention;

FIG. 10 is a schematic structural view of a side baffle and an overflow plate according to an embodiment of the present invention;

FIG. 11 is a schematic structural view of a side sealing plate, a throttle plate and a liquid separating plate according to an embodiment of the present invention;

in the figure:

1. a housing; 2. a flash structure; 3. a liquid separating structure; 101. a refrigerant inlet; 21. a throttle plate; 22. a first gas-liquid separation space; 211. an orifice; 212. a second throttle plate; 213. an inclined portion; 214. a planar portion; 102. an air supplement port; 23. a filtrate plate; 231. a filtrate well; 24. a liquid accumulation space; 25. a baffle plate; 31. an overflow plate; 26. a second gas-liquid separation space; 311. an overflowing hole; 4. side baffles; 103. an exhaust region; 41. an air outlet; 42. a gas baffle; 5. a filtering mechanism; 104. an exhaust port; 6. a heat exchange tube; 32. a liquid separation plate; 33. a liquid separating space; 321. a liquid separation hole; 7. and (4) side sealing plates.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.

The shell-and-tube heat exchanger shown in fig. 1 to 11 includes a shell 1, and a flash structure 2 and a liquid separating structure 3 which are arranged in the shell 1, wherein a refrigerant inlet 101 is arranged on the shell 1, the liquid separating structure 3 is arranged on a side of the flash structure 2 away from the refrigerant inlet 101, and refrigerant entering from the refrigerant inlet 101 sequentially flows through the flash structure 2 and the liquid separating structure 3. The refrigerant entering from the refrigerant inlet 101 sequentially passes through the throttling of the flash vaporization structure 2 and the liquid separation of the liquid separation structure 3, and then contacts with the heat exchange tube arranged in the shell 1, so that the flash vaporization, the liquid separation and the heat exchange of the refrigerant are completed. Place flash structure 2 in the shell and tube heat exchanger in, improve the product integration level, reduce connecting line's use and reduce the potential safety hazard that pipeline vibration, refrigerant leaked, the refrigerant after 2 throttles of flash structure is carrying out gas-liquid separation simultaneously, can improve and divide liquid homogeneity, reduces simultaneously that the refrigerant strikes the problem that the refrigerant splashes and avoid outside the heat exchange tube and cause the refrigerant, reinforcing cloth membrane effect improves coefficient of heat transfer.

The flash structure 2 includes at least two throttle plates 21, all the throttle plates 21 are arranged in the casing 1 in parallel along a direction away from the refrigerant inlet 101, a first gas-liquid separation space 22 is defined by the throttle plate 21 at the uppermost layer and the casing 1 corresponding thereto, and by the throttle plates 21 at two adjacent layers and the casing 1 corresponding thereto, the refrigerant entering from the refrigerant inlet 101 flows through all the first gas-liquid separation spaces 22 in sequence. By arranging the plurality of throttle plates 21, the refrigerant is throttled for a plurality of times in the shell 1, and the throttling flash effect of the shell-and-tube heat exchanger on the refrigerant can be effectively improved in the first gas-liquid separation space 22.

Throttle holes 211 are formed at one end of each throttle plate 21, and the throttle holes 211 of two adjacent throttle plates 21 are arranged alternately. For example, in two adjacent throttle plates 21, the throttle hole 211 is provided at a first end of one throttle plate 21, and the throttle hole 211 is provided at a second end of the other throttle plate 21. That is, the flow path of the refrigerant between the throttle plates 21 is S-shaped, and the throttle flow path of the refrigerant is increased as much as possible in a certain space, thereby increasing the throttling effect of the refrigerant.

All the throttle plates 21 include at least a second throttle plate 212 positioned at the lowermost layer, an inclined portion 213 having an angle with the horizontal plane is formed on the second throttle plate 212, and the throttle hole 211 is provided on the inclined portion 213. The inclined portion 213 further achieves the effect of gas-liquid separation, the liquid-phase refrigerant flows along the inclined portion 213 under the action of gravity, the gaseous refrigerant remains above the liquid-phase refrigerant, and therefore the effect of gas-liquid separation is achieved, and meanwhile, the throttle hole 211 is arranged at the inclined portion 213, so that the liquid-phase refrigerant can flow downwards through the throttle hole 211 as far as possible, and the effect of gas-liquid separation is further increased.

The second throttle plate 212 includes a flat portion 214 and an inclined portion 213 arranged in parallel with each other in the width direction of the second throttle plate 212, the flat portion 214 and the adjacent throttle plate 21 have a space therebetween through which the refrigerant flows, and the space between the inclined portion 213 and the adjacent throttle plate 21 gradually increases in a direction away from the flat portion 214.

An air supplement port 102 is arranged on the shell 1, and the air supplement port 102 is communicated with the space. The gas-liquid separated refrigerant passing through the at least one throttle plate 21 still contains liquid-phase refrigerant, but the amount of the liquid-phase refrigerant is relatively small, and the requirement for the compressor to supplement air can be met, so that the gas supplementing port 102 can be arranged at the interval to supplement air to the compressor by using the gas-phase refrigerant in the interval.

The flash structure 2 further comprises a liquid filtering plate 23, the liquid filtering plate 23 is arranged on the inclined portion 213, a liquid filtering hole 231 is formed in the liquid filtering plate 23, the liquid filtering plate 23 and a part of the liquid filtering plate 23 are formed by enclosing the inclined portion 213 and the corresponding shell 1 together to form a liquid loading space 24, and the liquid filtering plate 23 and a part of the inclined portion 213 are adjacent to each other and the throttle plate 21 and the corresponding shell 1 together enclose a first gas-liquid separation space 22. The refrigerant above the second throttle plate 212 is further separated by the filtrate plate 23, after the liquid drops with larger size contact the filtrate plate 23, the liquid drops are converged in the liquid accumulation space 24 through the filtrate hole 231 under the action of air flow blowing, and the liquid-phase refrigerant with a certain liquid level height is formed in the liquid accumulation space 24, so that the filtrate plate 23 can weaken the blowing of the gas-phase refrigerant to the liquid level, and further, a liquid seal is formed at the throttle hole 211 of the second throttle plate 212, thereby ensuring the stable operation of the throttle hole 211.

The flash structure 2 further comprises a plurality of baffles 25, all of the baffles 25 being arranged alternately with the first gas-liquid separation space 22. By using the plurality of baffles 25, the flowing distance of the refrigerant in the first gas-liquid separation space 22 is increased as much as possible, and when the refrigerant collides with the baffles 25, small refrigerant droplets are condensed into large droplets in the collision process, so that gas-liquid separation is realized.

All the baffles 25 are arranged in a staggered manner. The gravity of the refrigerant is fully utilized for liquid separation, and the liquid separation effect is improved. Preferably an upper baffle and a lower baffle, spaced apart.

The liquid separating structure 3 includes an overflow plate 31, all the throttle plates 21 include a second throttle plate 212 located at the lowermost layer, the overflow plate 31 is disposed below the second throttle plate 212, and a second gas-liquid separating space 26 is defined between the overflow plate 31, the second throttle plate 212 and the corresponding shell 1. The gas-liquid two-phase refrigerant enters the second gas-liquid separation space 26, and when the small liquid droplets flow downward, the small liquid droplets collide with the overflow plate 31 and are condensed into large liquid droplets, so that gas-liquid collision separation is realized. Meanwhile, the liquid droplets naturally settle to the bottom of the second gas-liquid separation space 26 by gravity, and gas-liquid gravity separation is realized.

The flow passing plate 31 is provided with a flow passing hole 311, and the flow passing hole 311 is arranged in a staggered manner with the throttle hole 211 of the second throttle plate 212, so that the flow distance of the refrigerant is increased as much as possible. Preferably, a second end of the second throttle plate 212 is provided with a throttle bore 211, while an overflow bore 311 is located opposite the first end of the second throttle plate 212.

Specifically, the number of the overflowing holes 311 is plural.

The shell-and-tube heat exchanger includes a side baffle 4, the side baffle 4 is located below the second throttle plate 212 and on one side of the flow-through plate 31, the second throttle plate 212 and a part of the side baffle 4 together enclose the second gas-liquid separation space 26 on the first side of the side baffle 4, and the side baffle 4 and the corresponding shell 1 constitute an exhaust region 103 on the second side of the side baffle 4. Utilize side shield 4 can keep out and collect the liquid drop that splashes among the falling liquid film evaporation process, conveniently directly deliver to the exhaust region 103 with the gaseous state refrigerant in the second gas-liquid separation space 26 simultaneously in, avoid gaseous state refrigerant to get into and divide liquid structure 3 and heat exchange tube region, improve the liquid separating effect of dividing liquid structure 3 and the heat transfer effect of heat exchange tube.

The side baffle 4 is provided with a gas outlet 41, and the second gas-liquid separation space 26 is communicated with the gas discharge area 103 through the gas outlet 41.

The air outlet 41 is provided with a filtering mechanism 5. The air flow entering the exhaust area 103 through the air outlet 41 is filtered by the filter mechanism 5, so that liquid droplets carried in the air flow contact the filter mechanism 5 and form large liquid droplets under the adsorption action of the filter mechanism 5 to drop into the second gas-liquid separation space 26, the purpose of gas-liquid screen separation is achieved, and finally the reliability of the gaseous refrigerant in the exhaust area 103 is ensured.

The overflowing plate 31 is provided with an overflowing hole 311, and the air outlet 41 is located above the overflowing hole 311. The large liquid drops formed by the filtering mechanism 5 can directly enter the liquid separating structure 3 for liquid separation after dropping into the second gas-liquid separating space 26, so that the filtering effect of the filtering mechanism 5 is prevented from being influenced because the large liquid drops are taken away by the airflow again.

Preferably, the filter mechanism 5 comprises a gas-liquid filter screen.

An air outlet 104 is arranged on the shell 1, and an air baffle plate 42 is arranged between the air outlet 41 and the air outlet 104. And the gas stroke from the gas outlet 41 to the gas outlet 104 is increased to form a U-shaped gas passage, so that the hidden trouble of liquid carrying during gas suction of the compressor is reduced.

The shell and tube heat exchanger further comprises a plurality of heat exchange tubes 6, all the heat exchange tubes 6 are arranged below the liquid separating structure 3, and all the heat exchange tubes 6 are located on the first side of the side baffle 4. The side baffle 4 is fully utilized to form a U-shaped air passage (a second gas-liquid separation space 26-a liquid separation structure 3-a heat exchange structure-an exhaust area 103), so that the stroke of a gaseous refrigerant formed after the liquid refrigerant absorbs heat is increased, and the hidden danger of liquid carrying during air suction of the compressor is reduced.

The liquid separating structure 3 further comprises at least two liquid separating plates 32, all the liquid separating plates 32 are arranged below the overflowing plate 31 in parallel, and liquid separating spaces 33 are formed between the uppermost liquid separating plate 32 and the overflowing plate 31 and between two adjacent liquid separating plates 32. By providing a plurality of liquid separation plates 32, the liquid separation effect of the liquid separation structure 3 is further increased. The liquid-phase refrigerant passes through the plurality of liquid-separating spaces 33 in sequence, thereby achieving an effect of uniform liquid separation. Particularly, the liquid-phase refrigerant forms a stable liquid seal above the liquid separation holes, the refrigerant at different positions is in the same state, no air flow blows around the liquid level, and therefore the liquid-phase refrigerant is separated through the liquid separation holes only under the action of gravity. Meanwhile, the phenomenon that the film distribution effect is influenced by over-high flow velocity sprayed to the outer wall surface of the heat exchange tube 6 after gas-liquid two-phase refrigerant is mixed and separated is avoided.

The liquid separation plates 32 are provided with liquid separation holes 321, and the liquid separation holes 321 in two adjacent liquid separation plates 32 are staggered, so that the liquid separation effect is improved.

Specifically, in two adjacent liquid separation plates 32, the axes of the liquid separation holes 321 in the liquid separation plate 32 in the upper layer are not collinear with the axes of the liquid separation holes 321 in the liquid separation plate 32 in the lower layer, and there may be a gap in the x direction and/or the y direction in the horizontal direction.

The flash structure 2 comprises at least two throttle plates 21, the liquid separating structure 3 further comprises at least two liquid separating plates 32, a side sealing plate 7 is connected between the throttle plate 21 on the uppermost layer and the edge of the liquid separating plate 32 on the same side on the lowermost layer, and the side sealing plate 7 and the corresponding part of the shell 1 are arranged in a profiling mode. Utilize side shrouding 7 to make flash structure 2 and divide liquid structure 3 to form a whole, side shrouding 7 can also further increase flash structure 2 and divide liquid structure 3's sealed effect simultaneously, avoids flash structure 2 and divides liquid structure 3 all to need directly to seal up with casing 1's internal surface and set up and increase the processing degree of difficulty.

Specially, shell and tube heat exchanger still includes the side shrouding, and the side shrouding seals the first end of all throttle plates 21 and the first end of all minute liquid boards 32 with baffling board 25 parallel arrangement, increases flash structure 2 and divides liquid structure 3's sealed effect, avoids flash structure 2 and divides liquid structure 3 all to need directly to seal up with casing 1's internal surface and set up and increase the processing degree of difficulty.

Examples

Take the example where the flash structure 2 includes two throttle plates 21 and the liquid separation structure 3 includes two liquid separation plates 32:

in the direction away from the refrigerant inlet 101, the two throttle plates 21 are a primary throttle plate and a secondary throttle plate (second throttle plate 212), respectively, and the two liquid-separating plates 32 are a primary liquid-separating plate and a secondary liquid-separating plate, respectively.

A liquid inlet pipe is arranged at the refrigerant inlet 101, an air supplementing pipe is arranged at the air supplementing port 102, and an exhaust pipe is arranged at the exhaust port 104.

The high-temperature high-pressure liquid-phase refrigerant discharged by the condenser enters the evaporator through the liquid inlet pipe at the upper part of the shell 1, and the refrigerant flows downwards and passes through the primary throttling hole on the primary throttling plate to realize throttling and pressure reduction and is converted into a gas-liquid two-phase refrigerant. The primary throttle hole is positioned at one axial end of the heat exchanger. The gas-liquid two-phase refrigerant enters a first gas-liquid separation space 22, and the first gas-liquid separation space 22 consists of a first-stage throttle plate at the top, a second-stage throttle plate at the bottom, an axial side edge seal, a circumferential side seal plate 7 and the inner wall surface of the shell 1. For example, baffles 25 are arranged in the first gas-liquid separation space 22 along the axial direction of the heat exchanger in a staggered manner. The gas-liquid two-phase refrigerant passes through the upper baffle plate and the lower baffle plate, and gas-liquid separation is realized through collision. One end of the secondary throttle plate in the circumferential direction is bent to form an inclined downward structure, a secondary throttle hole is formed in one axial end of the secondary throttle plate in the lower position, a horizontally-placed filtrate plate 23 is arranged in the middle of the inclined surface of the secondary throttle plate, and a filtrate hole 231 is formed in the filtrate plate 23. Therefore, the bottom of the liquid filtering plate 23, the second-stage throttle plate, the side sealing plates 7 and the side sealing plates form a liquid accumulating space 24, and the liquid accumulating space 24 is located at the bottom of the first gas-liquid separating space 22, so that the liquid refrigerant is converged under the action of gravity and the action of air flow blowing. In the first gas-liquid separation space 22, the gas-liquid two-phase refrigerant flows axially along the shell 1, when passing through the upper baffle plate and the lower baffle plate, the two-phase refrigerant collides with the two-phase refrigerant and changes the flow direction, the small liquid drops are condensed into large liquid drops, on one hand, the large liquid drops drop downwards along the baffle plate 25 and the side sealing plate 7, on the other hand, the large liquid drops gradually drop at the bottom of the space under the action of gravity when flowing axially, and finally the large liquid drops contact the top of the filtrate plate 23 and are converged in the liquid accumulation space 24 through the filtrate hole 231 under the action of air flow blowing. Liquid-phase refrigerant forms certain liquid level height in hydrops space 24, and filtrating board 23 can weaken gaseous phase refrigerant and blow the liquid level, and then forms the liquid seal at second grade orifice, makes orifice 211 steady operation. The primary throttle hole and the secondary throttle hole are respectively arranged at the two axial ends of the heat exchanger, so that the axial length of the heat exchanger is fully utilized to increase the flow stroke of the refrigerant, and the gas-liquid separation effect is enhanced. At the same end of the axial secondary orifice of the heat exchanger and at the other end in the circumferential direction, the shell 1 is provided with an air supplementing pipe, and the gas-phase refrigerant separated from the first gas-liquid separation space 22 is guided to enter the compressor for supplementing air.

The two-phase refrigerant after the secondary throttling enters a second gas-liquid separation space 26, and the second gas-liquid separation space 26 consists of a secondary throttling plate at the top, a flow passing plate 31 at the bottom, a circumferential gas outlet plate and an axial side sealing plate. The end of the side closing plate far away from the secondary orifice and the higher position are processed with air outlets, meanwhile, a gas-liquid filter screen (filter mechanism 5) is arranged around the air outlets in the second gas-liquid separation space 26, and an overflowing hole 311 is processed at the end of the overflowing plate 31 far away from the secondary orifice. The two-phase refrigerant enters the second gas-liquid separation space 26, and the small droplets collide with the overflow plate 31 to be condensed into large droplets when flowing downward, so that gas-liquid collision separation is realized. Meanwhile, the liquid drops naturally settle to the bottom of the second gas-liquid separation space 26 in a large space by utilizing gravity, and gas-liquid gravity separation is realized. When the air flow carries a small number of fine droplets to the air outlet at a higher position, the fine droplets contact the gas-liquid filter screen, and the small droplets form large droplets under the adsorption action of the gas-liquid filter screen and fall to the bottom of the second gas-liquid separation space 26, so that the gas-liquid filter screen separation is realized. Finally, the liquid drops pass through the overflowing hole 311 under the blowing action of the axial flowing air flow, and the refrigerant gas enters the heat exchange space of the heat exchanger through the air outlet hole.

The liquid phase refrigerant enters the primary liquid separation space 33 through the overflowing hole 311, and the bottom of the primary liquid separation space is a primary liquid separation plate. Liquid separating holes 321 which are uniformly distributed are machined in the axial direction and the circumferential direction of the heat exchanger on the first-stage liquid separating plate, a liquid-phase refrigerant enters the second-stage liquid separating space through the liquid separating holes 321 on the first-stage liquid separating plate, the second-stage liquid separating plate is arranged at the bottom of the second-stage liquid separating plate, and the liquid separating holes 321 which are uniformly distributed are machined in the axial direction and the circumferential direction of the heat exchanger on the second-stage liquid separating plate. In the first-stage liquid separation space and the second-stage liquid separation space, the liquid-phase refrigerant forms a stable liquid seal above the liquid separation holes 321, the states of the refrigerants at different positions are the same, no air flow blows around the liquid level, and therefore liquid is separated through the liquid separation holes 321 only under the action of gravity. Meanwhile, the phenomenon that the film distribution effect is influenced by over-high flow velocity sprayed to the outer wall surface of the heat exchange tube 6 after gas-liquid two-phase refrigerant is mixed and separated is avoided. The liquid separating holes 321 on the two liquid separating plates 32 are distributed in a staggered manner along the axial direction and the circumferential direction so as to enhance the liquid separating effect.

An air conditioning unit comprises the shell-and-tube heat exchanger.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is specific and detailed, but not to be understood as limiting the scope of the present invention. It should be noted that various changes and modifications can be made by those skilled in the art without departing from the spirit of the invention, and these changes and modifications are all within the scope of the invention. Therefore, the protection scope of the present patent should be subject to the appended claims.

Claims

1. A shell and tube heat exchanger which is characterized in that: including casing (1) with set up in flash structure (2) and divide liquid structure (3) in casing (1), be provided with refrigerant inlet (101) on casing (1), divide liquid structure (3) set up in flash structure (2) are kept away from one side of refrigerant inlet (101), just the refrigerant that refrigerant inlet (101) got into flows through in proper order flash structure (2) with divide liquid structure (3).

2. The shell and tube heat exchanger of claim 1 wherein: the flash structure (2) comprises at least two throttle plates (21), all the throttle plates (21) are arranged in the shell (1) in parallel along the direction far away from the refrigerant inlet (101), a first gas-liquid separation space (22) is enclosed by the throttle plate (21) on the uppermost layer and the shell (1) corresponding to the throttle plate (21) and the two adjacent throttle plates (21) and the shell (1) corresponding to the throttle plate, and refrigerant entering the refrigerant inlet (101) sequentially flows through all the first gas-liquid separation spaces (22).

3. The shell and tube heat exchanger of claim 2 wherein: one end of each throttle plate (21) is provided with a throttle hole (211), and the throttle holes (211) on two adjacent throttle plates (21) are arranged in a staggered mode.

4. The shell and tube heat exchanger of claim 3 wherein: all the throttle plates (21) at least comprise a second throttle plate (212) positioned at the lowest layer, an inclined part (213) forming an included angle with the horizontal plane is formed on the second throttle plate (212), and the throttle holes (211) are arranged on the inclined part (213).

5. The shell and tube heat exchanger of claim 4 wherein: the second throttle plate (212) includes a flat portion (214) and an inclined portion (213) arranged in parallel in the width direction of the second throttle plate (212), a space for refrigerant to flow is provided between the flat portion (214) and the adjacent throttle plate (21), and the space between the inclined portion (213) and the adjacent throttle plate (21) gradually increases in the direction away from the flat portion (214).

6. The shell and tube heat exchanger of claim 5 wherein: an air supplementing opening (102) is formed in the shell (1), and the air supplementing opening (102) is communicated with the space.

7. The shell and tube heat exchanger of claim 4 wherein: flash structure (2) still include filtrate board (23), filtrate board (23) set up in on rake (213), be provided with filtrate hole (231) on filtrate board (23), just filtrate board (23), part rake (213) and corresponding casing (1) encloses into hydrops space (24) jointly, filtrate board (23), part rake (213), adjacent throttle plate (21) and corresponding casing (1) encloses into first gas-liquid separation space (22) jointly.

8. The shell and tube heat exchanger of claim 7 wherein: the flash structure (2) further comprises a plurality of baffle plates (25), and all the baffle plates (25) are arranged in the first gas-liquid separation space (22) in a staggered mode.

9. The shell and tube heat exchanger of claim 2 wherein: the liquid separating structure (3) comprises flow passing plates (31), all the throttle plates (21) comprise second throttle plates (212) positioned at the lowest layer, the flow passing plates (31) are arranged below the second throttle plates (212), and second gas-liquid separating spaces (26) are enclosed among the flow passing plates (31), the second throttle plates (212) and the corresponding shell (1).

10. The shell and tube heat exchanger of claim 9 wherein: and an overflowing hole (311) is formed in the overflowing plate (31), and the overflowing hole (311) and the throttling hole (211) in the second throttling plate (212) are arranged in a staggered mode.

11. The shell and tube heat exchanger of claim 9 wherein: the shell-and-tube heat exchanger comprises side baffles (4), wherein the side baffles (4) are positioned below the second throttle plates (212) and on one side of the over-flow plate (31), the second throttle plates (212) and part of the side baffles (4) surround the second gas-liquid separation space (26) together on the first side of the side baffles (4), and the side baffles (4) and the corresponding shell (1) form an exhaust area (103) on the second side of the side baffles (4).

12. The shell and tube heat exchanger of claim 11 wherein: the side baffle (4) is provided with an air outlet (41), and the second gas-liquid separation space (26) is communicated with the exhaust area (103) through the air outlet (41).

13. The shell and tube heat exchanger of claim 12 wherein: and a filtering mechanism (5) is arranged at the air outlet (41).

14. The shell and tube heat exchanger of claim 12 wherein: an overflowing hole (311) is formed in the overflowing plate (31), and the air outlet (41) is located above the overflowing hole (311).

15. The shell and tube heat exchanger of claim 12 wherein: an air outlet (104) is formed in the shell (1), and an air baffle plate is arranged between the air outlet (41) and the air outlet (104).

16. The shell and tube heat exchanger of claim 11 wherein: the shell and tube heat exchanger further comprises a plurality of heat exchange tubes (6), all the heat exchange tubes (6) are arranged below the liquid separating structure (3), and all the heat exchange tubes (6) are located on the first side of the side baffle (4).

17. The shell and tube heat exchanger of claim 9 wherein: the liquid separating structure (3) further comprises at least two liquid separating plates (32), all the liquid separating plates (32) are arranged below the overflowing plate (31) in parallel, and liquid separating spaces (33) are formed between the uppermost liquid separating plate (32) and the overflowing plate (31) and between the adjacent two liquid separating plates (32).

18. The shell and tube heat exchanger of claim 17 wherein: the liquid separation plates (32) are provided with liquid separation holes (321), and the liquid separation holes (321) on two adjacent liquid separation plates (32) are arranged in a staggered mode.

19. The shell and tube heat exchanger of claim 1 wherein: the flash structure (2) comprises at least two throttle plates (21), the liquid separating structure (3) further comprises at least two liquid separating plates (32), the throttle plate (21) on the uppermost layer and the liquid separating plate (32) on the lowermost layer are connected with side sealing plates (7) between edges of the same side, and the side sealing plates (7) and corresponding parts of the shell (1) are arranged in a copying manner.

20. An air conditioning unit, its characterized in that: comprising the shell and tube heat exchanger of any one of claims 1 through 19.