Falling film evaporator

Abstract

A gas-liquid separation cavity is formed in a shell, a falling film heat exchange tube set is arranged in the gas-liquid separation cavity and located above a flooded heat exchange tube set, and a gas baffle is arranged in the gas-liquid separation cavity. The gas baffle is arranged on the outer side of the falling film heat exchange tube set in the horizontal direction, and the gas baffle and the falling film heat exchange tube set are arranged in a spaced mode to form a first gas guide space. The first gas guide space provides an additional circulation space for the gaseous refrigerant, the gaseous refrigerant formed at the falling-film heat exchange tube set can flow towards the side of the falling-film heat exchange tube set to enter the first gas guide space and then flow out of the falling-film heat exchange tube set along the first gas guide space, the flowability of the gaseous refrigerant at the falling-film heat exchange tube set is enhanced, and the heat exchange efficiency of the falling-film heat exchange tube set is improved. The liquid refrigerant at the falling film heat exchange tube group is vaporized more sufficiently, and the condition that the compressor sucks air and carries liquid is improved. In addition, the airflow direction changes in the process that the gaseous refrigerant flows along the first air guide space, separation of the two-phase refrigerant is promoted, and the situation that the compressor sucks air and carries liquid is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat exchange equipment, in particular to a falling film evaporator. BACKGROUND

[0002] At present, the falling film evaporator is a common evaporator form of the water chiller unit. The lower part of the falling film evaporator forms a full-liquid zone, and the upper part forms a falling film zone. The throttled two-phase refrigerant sprays from the upper part of the falling film zone, flows along the surface of the heat exchange tube of the falling film zone, and forms a liquid film. In this process, part of the liquid refrigerant evaporates and exchanges heat, and the liquid refrigerant that has not evaporated drops into the full-liquid zone to supplement the liquid in the full-liquid zone. The liquid refrigerant in the full-liquid zone forms a pool boiling evaporation heat exchange.

[0003] In the falling film evaporator, the gaseous refrigerant in the falling film zone and the full-liquid zone is collected to the two sides of the falling film zone, flows through the liquid blocking plate, and then flows to the suction port of the compressor. However, the gaseous refrigerant formed by evaporation in the falling film zone is prone to carrying the liquid droplets around it to flow, which causes the refrigerant to flow back to the compressor in the form of liquid, increasing the risk of damage to the compressor. CONTENT OF THE INVENTION

[0004] The embodiment of the present application provides a falling film evaporator which can improve the problem of liquid carrying in the suction of the compressor caused by the falling film evaporator.

[0005] The embodiment of the present application provides a falling film evaporator, which comprises a shell, a full-liquid heat exchange tube group, a falling film heat exchange tube group and a gas blocking plate. The shell has a gas-liquid separation cavity inside. The full-liquid heat exchange tube group is arranged in the gas-liquid separation cavity. The falling film heat exchange tube group is arranged in the gas-liquid separation cavity and above the full-liquid heat exchange tube group. The falling film heat exchange tube group comprises a plurality of falling film heat exchange main tubes arranged at intervals. The gas blocking plate is arranged in the gas-liquid separation cavity. In the horizontal direction, the gas blocking plate is arranged outside the falling film heat exchange tube group and is arranged at intervals with the falling film heat exchange tube group. A first gas guiding space is formed between the falling film heat exchange tube group and the gas blocking plate.

[0006] In some embodiments, in the horizontal direction, the width of the first gas guiding space is s, and s satisfies: 20mm≤s≤100mm.

[0007] In some embodiments, the falling film heat exchange tube group is arranged in the space surrounded by the gas blocking plate. The shell has a refrigerant inlet. The refrigerant inlet is in communication with the space surrounded by the gas blocking plate, and the refrigerant inlet is above the falling film heat exchange tube group. In the horizontal direction, the gas blocking plate covers at least part of the falling film heat exchange main tube farthest from the refrigerant inlet.

[0008] In some embodiments, the baffle plate comprises a main plate body and a flange plate, the main plate body is connected to the shell and is arranged outside the falling-film heat exchange tube group; the flange plate is arranged on the side of the main plate body away from the falling-film heat exchange tube group and is connected to the main plate body, the flange plate is arranged at an angle with the main plate body, and the angle is α, 90°≤α<180°.

[0009] In some embodiments, the main plate body is in the shape of a flat plate extending in the vertical direction; the flange plate is in the shape of a flat plate extending in the horizontal direction.

[0010] In some embodiments, in the horizontal direction, the width of the flange plate is L, and L satisfies: 10mm≤L≤25mm.

[0011] In some embodiments, in the vertical direction, the falling-film heat exchange tube group is arranged spaced apart from the falling-film heat exchange tube group, and a second air guide space is formed between the falling-film heat exchange tube group and the falling-film heat exchange tube group; in the horizontal direction, the baffle plate is arranged spaced apart from the shell, and a third air guide space is formed between the baffle plate and the shell, so that part of the gaseous refrigerant formed at the falling-film heat exchange tube group enters the first air guide space, the second air guide space and the third air guide space in sequence through the gaps between the plurality of falling-film heat exchange main pipes.

[0012] In some embodiments, the shell comprises: an outer shell; a liquid baffle plate that separates the inner space of the outer shell into the gas-liquid separation chamber and the gas outlet chamber, the gas-liquid separation chamber is located below the gas outlet chamber, and the baffle plate is arranged on the liquid baffle plate; wherein the liquid baffle plate has a refrigerant inlet, the refrigerant inlet is in communication with the space surrounded by the baffle plate and is arranged spaced apart from the gas outlet chamber, so as to send gas-liquid mixed refrigerant to the space surrounded by the baffle plate through the refrigerant inlet; the liquid baffle plate is in a porous structure to communicate the gas-liquid separation chamber and the gas outlet chamber, and the liquid baffle plate is used to filter liquid refrigerant mixed in gaseous refrigerant flowing from the gas-liquid separation chamber to the gas outlet chamber.

[0013] In some embodiments, the axial direction of the falling-film heat exchange main pipe is parallel to the horizontal direction; in the first direction perpendicular to the axial direction of the falling-film heat exchange main pipe, the refrigerant inlet is arranged in the middle region of the liquid baffle plate, and in the axial direction of the falling-film heat exchange main pipe, the refrigerant inlet extends to the inner wall surface of the outer shell.

[0014] In some embodiments, the falling-film evaporator further comprises a liquid distributor, the liquid distributor is partially arranged in the gas outlet chamber and covers the refrigerant inlet and is connected to the liquid baffle plate, so as to spray gas-liquid mixed refrigerant to the refrigerant inlet.

[0015] In some embodiments, the axial direction of the falling film heat exchange main pipe is parallel to the horizontal direction; the falling film heat exchange pipe group comprises a plurality of falling film pipe units, each falling film pipe unit comprises a plurality of falling film heat exchange main pipes arranged side by side in the vertical direction, and a plurality of falling film pipe units are arranged side by side and spaced apart in a first direction perpendicular to the axial direction of the falling film heat exchange main pipe.

[0016] In some embodiments, two adjacent falling film pipe units are arranged staggered in the vertical direction.

[0017] In some embodiments, the falling film evaporator comprises two air baffle plates arranged opposite in the first direction, the air baffle plates are connected with the shell, and the falling film heat exchange pipe group is arranged in the space enclosed by the two air baffle plates and the shell.

[0018] Based on the falling film evaporator of the embodiments of the present application, the air baffle plate is arranged outside the falling film heat exchange pipe group, and the falling film heat exchange pipe group and the air baffle plate are spaced apart to form a first air guide space. The gaseous refrigerant formed at the falling film heat exchange pipe group can flow into the first air guide space from the side of the falling film heat exchange pipe group, and then flow out of the falling film heat exchange pipe group along the first air guide space. The first air guide space provides additional flow space for the gaseous refrigerant, enhances the flow of the gaseous refrigerant at the falling film heat exchange pipe group, reduces the accumulation of gaseous refrigerant in the falling film heat exchange pipe group, thereby improving the evaporation efficiency. In this way, the liquid refrigerant vaporization at the falling film heat exchange pipe group is more sufficient, which helps to improve the situation of liquid entrainment in the compressor suction. In addition, the flow direction of the gaseous refrigerant changes during the flow along the first air guide space, which promotes the separation of the two-phase refrigerant, further improving the situation of liquid entrainment in the compressor suction. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 FIG. 1 is a cross-sectional structure schematic diagram of a falling film evaporator according to an embodiment of the present application;

[0021] Figure 2 FIG. 2 is a gas flow direction schematic diagram of a falling film evaporator according to an embodiment of the present application;

[0022] Figure 3 FIG. 3 is a cross-sectional structure schematic diagram of a falling film evaporator according to an embodiment of the present application; Figure 1 FIG. 4 is a local enlarged schematic diagram of A in FIG. 3;

[0023] Figure 4 FIG. 5 is a structure schematic diagram of an air baffle plate according to an embodiment of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0025] 1. falling film evaporator; 1a, first gas guide space; 1b, second gas guide space; 1c, third gas guide space;

[0026] 10. shell; 11, outer shell; 110, gas-liquid separation chamber; 130, gas outlet chamber; 140, gas outlet; 12, liquid blocking plate; 120, refrigerant inlet;

[0027] 20. full-liquid heat exchange tube group; 21, full-liquid heat exchange main tube;

[0028] 30. falling film heat exchange tube group; 31, falling film heat exchange main tube;

[0029] 40. gas blocking plate; 41, main plate body; 42, flange plate;

[0030] 50. liquid distributor. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0032] At present, the application of horizontal tube falling film evaporator in the field of refrigeration is mainly based on vapor compression refrigeration. Among them, the falling film evaporator has full-liquid area and falling film area at the same time. During the liquid distribution and falling film process, the liquid refrigerant on the surface of the falling film area heat exchange tube occurs film boiling, and the full-liquid area heat exchange tube is immersed in the liquid refrigerant to form pool boiling. The gaseous refrigerant at the falling film area and the full-liquid area is collected to the both sides of the falling film area, and then flows to the compressor suction port after the liquid blocking plate. However, the gaseous refrigerant formed by the film boiling in the falling film area is easy to flow together with the surrounding small liquid droplets, which leads to liquid entrainment in the compressor suction, increasing the risk of compressor damage. Based on this, the present application provides a falling film evaporator.

[0033] Please refer to Figures 1-2 , the falling film evaporator 1 includes a shell 10, a full-liquid heat exchange tube group 20, a falling film heat exchange tube group 30, and a gas blocking plate 40. The shell 10 has a gas-liquid separation chamber 110 inside. The full-liquid heat exchange tube group 20 is arranged in the gas-liquid separation chamber 110. The falling film heat exchange tube group 30 is arranged in the gas-liquid separation chamber 110 and located above the full-liquid heat exchange tube group 20. Thus, the lower part of the gas-liquid separation chamber 110 forms a full-liquid area, and the upper part forms a falling film area. The full-liquid heat exchange tube group 20 includes a plurality of spaced full-liquid heat exchange main tubes 21. In the full-liquid area, the plurality of full-liquid heat exchange main tubes 21 are immersed in the refrigerant to form pool boiling heat exchange. The falling film heat exchange tube group 30 includes a plurality of spaced falling film heat exchange main tubes 31. In the falling film area, the refrigerant falling film heat exchange main tubes 31 flow on the surface and form a liquid film to form film boiling heat exchange.

[0034] In the embodiment, the baffle 40 is arranged in the gas-liquid separation chamber 110. In the horizontal direction X, the baffle 40 is arranged outside the falling film heat exchange tube group 30, and the baffle 40 is arranged spaced apart from the falling film heat exchange tube group 30, and a first gas guide space 1a is formed between the falling film heat exchange tube group 30 and the baffle 40. The gaseous refrigerant formed at the falling film heat exchange tube group 30 can flow to the side of the falling film heat exchange tube group 30 into the first gas guide space 1a, and then flow out of the falling film heat exchange tube group 30 along the first gas guide space 1a. The first gas guide space 1a provides additional flow space for the gaseous refrigerant, enhances the flow of the gaseous refrigerant at the falling film heat exchange tube group 30, reduces the accumulation of gaseous refrigerant in the falling film heat exchange tube group 30, thereby improving the evaporation efficiency, and the liquid refrigerant vaporization at the falling film heat exchange tube group 30 is more sufficient, and the situation of liquid suction by the compressor is improved.

[0035] Further, the gaseous refrigerant formed at the falling film heat exchange tube group 30 changes the flow direction during the process of flowing out of the falling film heat exchange tube group 30 along the first gas guide space 1a. Since the liquid droplets carried in the gaseous refrigerant cannot completely change direction with the gas flow, a part of the liquid droplets will hit the surface of the baffle 40 or drip to the area below the gas-liquid separation chamber 110 along the extension direction of the first gas guide space 1a. In this way, the ability of the gas flow to carry liquid droplets is reduced, and the risk of liquid refrigerant flowing back to the compressor is reduced.

[0036] Please refer to Figure 3 , in the horizontal direction X, the width of the first gas guide space 1a is s, that is, the distance between the falling film heat exchange main tube 31 of the falling film heat exchange tube group 30 closest to the baffle 40 and the baffle 40 is s, s satisfies: 20mm≤s≤100mm, optionally, s can be 20mm, 60mm, 80mm, 100mm or a range between any two of the above. Within this range, the gaseous refrigerant formed at the falling film heat exchange tube group 30 can flow smoothly along the first gas guide space 1a, neither the gas flow is blocked due to the space being too narrow, nor the blocking effect on the liquid refrigerant is reduced due to the space being too spacious. In actual application, the width s of the first gas guide space 1a can be set according to the size of the shell 10, or can be set according to the heat exchange power.

[0037] It should be noted that the falling film evaporator 1 has a refrigerant inlet 120, and further comprises a liquid distributor 50 arranged in the shell 10 and above the falling film heat exchange tube group 30, the liquid distributor 50 is communicated with the refrigerant inlet 120 and is used to uniformly distribute the two-phase refrigerant to the falling film heat exchange main pipes 31 of the falling film heat exchange tube group 30. The liquid distributor 50 sprays the throttled two-phase refrigerant to the falling film area, and the two-phase refrigerant falls into the falling film area through the refrigerant inlet 120 and flows on the surface of the falling film heat exchange main pipes 31 to form a liquid film. In some embodiments, the falling film evaporator 1 is provided with a power circulation assembly, which provides power to circulate the refrigerant at the bottom of the gas-liquid separation chamber 110 back to the liquid distributor 50 for re-distribution, thereby increasing the circulation ratio of the refrigerant in the falling film evaporator 1 and achieving forced heat exchange effect.

[0038] In some embodiments, the falling film evaporator 1 comprises two gas blocking plates 40, which are arranged on both sides of the falling film heat exchange tube group 30 along the horizontal direction X, and the falling film heat exchange tube group 30 is arranged in the space surrounded by the gas blocking plates 40. The shell 10 has a refrigerant inlet 120, which is communicated with the space surrounded by the gas blocking plates 40 and is located above the falling film heat exchange tube group 30, so that the two-phase refrigerant sprayed downward through the refrigerant inlet 120 falls to the falling film heat exchange tube group 30 under the action of gravity and then exchanges heat on the surface of the falling film heat exchange main pipes 31. Along the horizontal direction X, the gas blocking plate 40 covers at least part of the falling film heat exchange main pipes 31 farthest from the refrigerant inlet, so that the gas blocking plate 40 can effectively block the space on both sides of the falling film heat exchange tube group 30, thereby forcing as much gaseous refrigerant at the falling film heat exchange tube group 30 as possible to flow along the first gas guide space 1a.

[0039] Optionally, along the axial direction of the falling film heat exchange main pipes 31, the gas blocking plate 40 has opposite first and second edges, and the plurality of falling film heat exchange main pipes 31 of the falling film heat exchange tube group 30 are located between the first and second edges, that is, the gas blocking plate 40 covers all the falling film heat exchange main pipes 31 of the falling film heat exchange tube group 30, and the bottom end surface of the gas blocking plate 40 is flush with the bottom of the falling film heat exchange main pipes 31 farthest from the refrigerant inlet, so that the gas blocking plate 40 can fully block the space on both sides of the falling film heat exchange tube group 30, and the length of the gas blocking plate 40 is moderate, which can maximize the flow of gaseous refrigerant along the first gas guide space 1a and avoid excessive hindering of the flow of gaseous refrigerant in the falling film evaporator 1, thereby reducing the impact on the overall efficiency of the falling film evaporator 1.

[0040] Please refer to Figure 4In the embodiments of the present application, the baffle 40 includes a main plate body 41 and a flange plate 42. The main plate body 41 is connected to the shell 10, and the main plate body 41 is arranged outside the falling-film heat exchange tube group 30. The main plate body 41 forms a barrier on both sides of the falling-film heat exchange tube group 30, so that a first gas guiding space 1a is formed between the main plate body 41 and the falling-film heat exchange tube group 30. The flange plate 42 is arranged on the side of the main plate body 41 away from the falling-film heat exchange tube group 30, and the flange plate 42 is connected to the main plate body 41. The flange plate 42 is arranged at an angle with the main plate body 41, and the angle is α, 90°≤α<180°. The flange plate 42 is inclined toward the side away from the falling-film heat exchange tube group 30. In this way, the airflow in the first gas guiding space 1a can be guided to the space on both sides of the falling-film heat exchange tube group 30, the probability of vortex or dead zone being formed in the bottom area of the main plate body 41 is reduced, and the flow efficiency of the gaseous refrigerant is improved.

[0041] In some embodiments, the main plate body 41 is in the shape of a flat plate extending in the vertical direction Y. The flow of the first gas guiding space 1a is relatively short, which helps to improve the flow efficiency of the gaseous refrigerant. The flange plate 42 is connected to the bottom edge of the main plate body 41. The flange plate 42 is in the shape of a flat plate extending in the horizontal direction X. The flange plate 42 can also be used to intercept the liquid refrigerant mixed in the airflow. When the gaseous refrigerant hits the flange plate 42, the liquid droplets carried in the gaseous refrigerant condense on the surface of the flange plate 42, and then fall into the full-liquid area.

[0042] In some embodiments, in the horizontal direction X, the width of the flange plate 42 is L, and L satisfies: 10mm≤L≤25mm. Within this range, the flange plate 42 can effectively guide the airflow in the first gas guiding space 1a to the space on both sides of the falling-film heat exchange tube group 30. If L<10mm, the flange plate 42 is too narrow, and it is difficult to effectively guide the gaseous refrigerant flowing through the first gas guiding space 1a to turn. If L>25mm, the flange plate 42 is too wide, which may cause a large dead zone to be formed above the flange plate 42, affecting the smoothness of the airflow and the heat exchange efficiency in the falling-film evaporator 1.

[0043] In the embodiments of the present application, the axial direction of the falling-film heat exchange main pipe 31 is parallel to the horizontal direction. The falling-film heat exchange tube group 30 includes a plurality of falling-film tube units. Each falling-film tube unit includes a plurality of falling-film heat exchange main pipes 31 arranged side by side in the vertical direction Y. In the same falling-film tube unit, the refrigerant falls from the upper falling-film heat exchange main pipe 31 to the adjacent lower falling-film heat exchange main pipe 31 under the action of gravity. The plurality of falling-film tube units are arranged side by side and spaced apart in a first direction perpendicular to the axial direction of the falling-film heat exchange main pipe 31. In this way, the gaseous refrigerant formed by each falling-film tube unit can flow from the gap between adjacent falling-film tube units to the first gas guiding space 1a.

[0044] In some embodiments, two adjacent falling film tube units are arranged staggered in the vertical direction Y. The staggered arrangement can ensure more uniform flow of the gaseous refrigerant between the falling film tube units, and provide a smooth flow path for the gaseous refrigerant, reducing the obstruction of the flow of gaseous refrigerant by the falling film heat exchange main tubes 31 in the adjacent falling film tube units, and helping to achieve a more efficient and stable heat exchange process.

[0045] In some embodiments, the falling film evaporator 1 includes two air baffles 40 arranged opposite in the first direction, the air baffles 40 are connected to the shell 10, and the falling film heat exchange tube group 30 is arranged in the space enclosed by the two air baffles 40 and the shell 10.

[0046] In some embodiments, in the vertical direction Y, the flooded heat exchange tube group 20 and the falling film heat exchange tube group 30 are arranged spaced apart, and a second air guide space 1b is formed between the flooded heat exchange tube group 20 and the falling film heat exchange tube group 30. The second air guide space 1b provides accommodation space for the gaseous refrigerant in the flooded zone and the falling film zone, reducing the interference between the heat exchange of the flooded heat exchange tube group 20 and the heat exchange of the falling film heat exchange tube group 30.

[0047] In the horizontal direction X, the air baffles 40 and the shell 10 are arranged spaced apart, and a third air guide space 1c is formed between the air baffles 40 and the shell 10. Some of the gaseous refrigerant formed at the falling film heat exchange tube group 30 enters the first air guide space 1a, the second air guide space 1b and the third air guide space 1c in sequence through the gaps between the multiple falling film heat exchange main tubes 31. Another part of the gaseous refrigerant formed at the falling film heat exchange tube group 30 enters the second air guide space 1b below through the gaps between the multiple falling film heat exchange main tubes 31, and then flows to the third air guide space 1c. In this way, the gaseous refrigerant formed at the falling film heat exchange tube group 30 flows to the second air guide space 1b along multiple paths, and the flow of the gaseous refrigerant is smoother. The gaseous refrigerant formed at the flooded heat exchange tube group 20 enters the second air guide space 1b and the third air guide space 1c in sequence.

[0048] In the embodiments of the present application, the flooded heat exchange tube group 20 includes multiple flooded tube units, each flooded tube unit includes multiple flooded heat exchange main tubes 21 arranged side by side in the vertical direction Y, and the axial direction of the flooded heat exchange main tubes 21 is parallel to the horizontal direction. The multiple flooded tube units are arranged side by side and spaced apart in the first direction perpendicular to the axial direction of the flooded heat exchange main tubes 21. In this way, the gaseous refrigerant formed by each flooded tube unit can flow to the second air guide channel 1b from the gaps between adjacent flooded tube units.

[0049] In some embodiments, the shell 10 comprises a housing 11 and a liquid baffle 12, the liquid baffle 12 separates the interior space of the housing 11 into a gas-liquid separation chamber 110 and a gas outlet chamber 130, the gas-liquid separation chamber 110 is located below the gas outlet chamber 130, and the gas baffle 40 is arranged on the liquid baffle 12. The housing 11 also has a gas outlet 140 communicating with the gas outlet chamber 130, and the gas outlet 140 is used to communicate with the compressor, wherein the gaseous refrigerant in the third gas guide space 1c passes through the liquid baffle 12, then flows through the gas outlet chamber 130 and the gas outlet 140 to enter the compressor.

[0050] The liquid baffle 12 has a refrigerant inlet 120, which communicates with the space surrounded by the gas baffle 40, and the refrigerant inlet 120 is arranged separately from the gas outlet chamber 130, wherein the liquid distributor 50 is arranged in the gas outlet chamber 130, the refrigerant inlet 120 and the gas outlet chamber 130 are arranged separately, and the liquid distributor 50 sends the gas-liquid mixed refrigerant to the space surrounded by the gas baffle 40 through the refrigerant inlet 120. The liquid baffle 12 has a porous structure to communicate the gas-liquid separation chamber 110 and the gas outlet chamber 130, and the liquid baffle 12 is used to filter the liquid refrigerant mixed in the gaseous refrigerant flowing from the gas-liquid separation chamber 110 to the gas outlet chamber 130. In the working process of the falling film evaporator 1, the gas flow collides with the liquid baffle 12 when passing through the liquid baffle 12, the gaseous refrigerant flows to the gas outlet chamber 130 through the gas holes of the liquid baffle 12, and then leaves the falling film evaporator 1 from the gas outlet 140 and enters the compressor, the liquid refrigerant mixed in the gas flow adheres to the surface of the liquid baffle 12 and accumulates into large droplets on the surface of the liquid baffle 12, and finally drops to the full-liquid zone.

[0051] In some embodiments, the liquid distributor 50 is partially arranged in the gas outlet chamber 130, wherein the liquid distributor 50 covers the refrigerant inlet 120 and is connected to the liquid baffle 12, so that the refrigerant inlet 120 is arranged separately from the gas outlet chamber 130, reducing the mutual interference between the gaseous refrigerant transportation and the liquid distribution falling film in the falling film evaporator 1. In practical application, the liquid distributor 50 has a liquid distribution chamber, an inlet and an outlet communicating with the liquid distribution chamber, the inlet is used to communicate with the refrigerant inlet pipe, and the outlet is used to communicate with the refrigerant inlet 120, the gas-liquid mixed refrigerant enters the falling film evaporator 1 from the refrigerant inlet pipe and then passes through the inlet, the liquid distribution chamber and the outlet to spray toward the refrigerant inlet 120, wherein the liquid refrigerant flows to the falling film heat exchange main pipe 31 under the action of gravity to complete the film boiling heat exchange.

[0052] In some embodiments, the axial direction of the falling film heat exchange main pipe 31 is parallel to the horizontal direction, and the refrigerant inlet 120 is arranged at the middle region of the liquid barrier plate 12 in the first direction perpendicular to the axial direction of the falling film heat exchange main pipe 31, which helps to distribute the refrigerant more evenly in the falling film heat exchange pipe group 30. It can be understood that if the refrigerant inlet 120 is close to the edge of the liquid barrier plate 12, it may cause uneven distribution of the refrigerant and affect the heat exchange efficiency. The liquid barrier plate 12 is partially located above the falling film heat exchange pipe group 30, and the gas barrier plate 40 is connected to the region of the liquid barrier plate 12 close to the refrigerant inlet 120.

[0053] Further, along the axial direction of the falling film heat exchange main pipe 31, the refrigerant inlet 120 extends to the inner wall surface of the shell 11, which provides sufficient liquid distribution space for the liquid distributor 50, so that the liquid refrigerant can fully cover the surface of the falling film heat exchange main pipe 31, thereby increasing the heat exchange area and further improving the heat exchange efficiency.

[0054] The same or similar reference numerals in the drawings of the embodiments correspond to the same or similar components; in the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationship in the drawings are only used for exemplary illustration, and cannot be understood as a limitation of the present patent, for those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0055] The above only describes the preferred embodiments of the present application and does not limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A falling film evaporator, characterized in that The application relates to a falling film evaporator. The falling film evaporator comprises: a shell with a gas-liquid separation chamber inside; a full-liquid heat exchange pipe group arranged in the gas-liquid separation chamber; a falling film heat exchange pipe group arranged in the gas-liquid separation chamber and above the full-liquid heat exchange pipe group, wherein the falling film heat exchange pipe group comprises a plurality of falling film heat exchange main pipes arranged at intervals; a gas baffle arranged in the gas-liquid separation chamber; wherein the gas baffle is arranged outside the falling film heat exchange pipe group in the horizontal direction and is arranged at intervals with the falling film heat exchange pipe group, and a first gas guide space is formed between the falling film heat exchange pipe group and the gas baffle.

2. The falling film evaporator according to claim 1, characterized in that In the horizontal direction, the width of the first gas guide space is s, and s satisfies 20mm<=s<=100mm.

3. The falling film evaporator of claim 1, wherein The falling film heat exchange pipe group is arranged in the space surrounded by the gas baffle; The shell has a refrigerant inlet, the refrigerant inlet is communicated with the space surrounded by the gas baffle, and the refrigerant inlet is above the falling film heat exchange pipe group, and in the horizontal direction, the gas baffle covers at least part of the falling film heat exchange main pipe farthest from the refrigerant inlet.

4. The falling film evaporator of claim 1, wherein The gas baffle comprises: a main plate body connected to the shell and arranged outside the falling film heat exchange pipe group; a flange plate arranged on the side of the main plate body away from the falling film heat exchange pipe group and connected to the main plate body, the flange plate is arranged at an angle with the main plate body, and the angle is alpha, and 90<=alpha<180.

5. The falling film evaporator according to claim 4, wherein the main plate body is a flat plate extending in the vertical direction; the flange plate is a flat plate extending in the horizontal direction.

6. The falling film evaporator of claim 4, wherein, In the horizontal direction, the width of the flange plate is L, and L satisfies 10mm<=L<=25mm.

7. The falling film evaporator according to claim 1, wherein in the vertical direction, the full-liquid heat exchange pipe group and the falling film heat exchange pipe group are arranged at intervals, and a second gas guide space is formed between the full-liquid heat exchange pipe group and the falling film heat exchange pipe group; in the horizontal direction, the gas baffle and the shell are arranged at intervals, and a third gas guide space is formed between the gas baffle and the shell, so that part of the gaseous refrigerant formed at the falling film heat exchange pipe group enters the first gas guide space, the second gas guide space and the third gas guide space in sequence through the gaps between the plurality of falling film heat exchange main pipes.

8. The falling-film evaporator of claim 1, wherein The shell comprises: an outer shell; a liquid baffle separating the internal space of the outer shell into the gas-liquid separation chamber and a gas outlet chamber, wherein the gas-liquid separation chamber is below the gas outlet chamber, and the gas baffle is arranged on the liquid baffle; wherein the liquid baffle has a refrigerant inlet communicated with the space surrounded by the gas baffle and arranged at intervals with the gas outlet chamber, so as to send gas-liquid mixed refrigerant into the space surrounded by the gas baffle through the refrigerant inlet; the liquid baffle is a porous structure to communicate the gas-liquid separation chamber and the gas outlet chamber, and the liquid baffle is used to filter the liquid refrigerant mixed in the gaseous refrigerant flowing from the gas-liquid separation chamber to the gas outlet chamber.

9. The falling film evaporator according to claim 8, wherein the axis of the falling film heat exchange main pipe is parallel to the horizontal direction. The refrigerant inlet is arranged in a middle region of the liquid baffle plate along a first direction perpendicular to an axial direction of the falling film heat exchange main pipe, and extends to an inner wall surface of the shell along the axial direction of the falling film heat exchange main pipe.

10. The falling film evaporator of claim 8, wherein, The falling film evaporator further comprises a liquid distributor, which is partially arranged in the gas outlet cavity, covers the refrigerant inlet, and is connected to the liquid baffle plate to spray the gas-liquid mixed refrigerant to the refrigerant inlet.

11. The falling film evaporator according to claim 1, wherein: the axial direction of the falling film heat exchange main pipe is parallel to a horizontal direction; the falling film heat exchange pipe group comprises a plurality of falling film pipe units, each of which comprises a plurality of falling film heat exchange main pipes arranged side by side along a vertical direction, and a plurality of the falling film pipe units are arranged side by side and spaced apart along a first direction perpendicular to the axial direction of the falling film heat exchange main pipe.

12. The falling film evaporator of claim 11, wherein, adjacent two falling film pipe units are arranged in a vertical direction staggered.

13. The falling-film evaporator of claim 11, wherein, The falling film evaporator comprises two gas baffle plates arranged opposite to each other along the first direction, the gas baffle plates are connected to the shell, and the falling film heat exchange pipe group is arranged in a space enclosed by the two gas baffle plates and the shell.

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