Device for preventing liquid entrainment by suction, falling-film heat exchanger and refrigeration system

Abstract

The application discloses a device for preventing liquid entrainment in suction, a falling-film heat exchanger and a refrigeration system, and relates to the field of air conditioning. The device comprises a ring-shaped body, the ring-shaped body comprising a first through hole, a plurality of air holes and a first liquid collecting groove; the first through hole penetrates the axial direction of the ring-shaped body, the air holes penetrate the wall of the ring-shaped body and are in communication with the first through hole; and the first liquid collecting groove is located downstream of at least part of the air holes. According to the above technical scheme, the air holes are located on the wall of the ring-shaped body, the first through hole penetrates the axial direction of the ring-shaped body, the air holes and the first through hole have different air inlet directions, so that the gas enters the ring-shaped body along different directions, the liquid carried in the gas entering through the air holes is blocked by the ring-shaped body, and the liquid condenses on the outer wall of the ring-shaped body and then flows to the first liquid collecting groove to be collected, the volume of the collected liquid is larger, and the liquid is not easy to be taken away by the gas, so that the liquid entrainment in suction is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of air conditioning, in particular to a device for preventing suction of liquid, a falling-film heat exchanger and a refrigeration system. BACKGROUND

[0002] The tank evaporator / tank condenser (referred to as high-efficiency tank) is a kind of high-efficiency heat exchanger which is combined by vertical cylinder and coil pipe.

[0003] The inventor found that at least the following problems exist in the prior art: the flow rate of refrigerant gas in the shell of the falling-film heat exchanger is high when the falling-film heat exchanger is used as an evaporator under refrigeration working conditions. The high-speed gas easily entrains the liquid refrigerant that is not dried in the falling-film zone and the full-liquid zone to the outlet of the heat exchanger, causing suction of liquid. This causes abnormal distribution of refrigerant in the system, increases the required refrigerant charge of the system, and in severe cases, even causes the compressor to compress liquid, damaging the compressor. SUMMARY

[0004] The present application provides a device for preventing suction of liquid, a falling-film heat exchanger and a refrigeration system to reduce the phenomenon of suction of liquid.

[0005] The present application provides a device for preventing suction of liquid, a falling-film heat exchanger and a refrigeration system to reduce the phenomenon of suction of liquid.

[0006] The annular body includes a first through hole, a plurality of air holes and a first liquid collecting groove. The first through hole penetrates the axial direction of the annular body. Each air hole penetrates the wall of the annular body and communicates with the first through hole. The first liquid collecting groove is located on the outer wall of the annular body and downstream of at least part of the air holes.

[0007] In some embodiments, the annular body further includes:

[0008] A second liquid collecting groove is located on the outer wall of the annular body and downstream of the first liquid collecting groove; and

[0009] A flow guide groove, one end of which communicates with the first liquid collecting groove, and the other end of which communicates with the second liquid collecting groove.

[0010] In some embodiments, the first liquid collecting groove is configured to surround a circle along the circumference of the outer wall of the annular body; and / or, the second liquid collecting groove is configured to surround a circle along the circumference of the outer wall of the annular body.

[0011] In some embodiments, the length direction of the flow guide groove is parallel to the axial direction of the annular body, and the flow guide groove is arranged on the outer wall of the annular body.

[0012] In some embodiments, the number of flow guide grooves is at least two, and each flow guide groove is dispersedly arranged along the circumference of the annular body.

[0013] In some embodiments, the first sump is located in the axial middle of the annular body.

[0014] In some embodiments, the second sump is located at an axial end of the annular body.

[0015] In some embodiments, the cross-sectional shape of the pore is one of the following: circular, elongated, and irregular.

[0016] In some embodiments, along the axial direction of the annular body, the flow area and / or arrangement density of each of the air holes is the same or gradually changes.

[0017] In some embodiments, the annular body further comprises:

[0018] The middle liquid collecting trough is located on the outer wall of the annular body and between the first liquid collecting trough and the second liquid collecting trough.

[0019] An embodiment of the present invention further provides a falling film heat exchanger, comprising the device for preventing liquid from being carried over by air suction provided by any technical solution of the present invention.

[0020] In some embodiments, the falling film heat exchanger further comprises:

[0021] a housing including an inner cavity;

[0022] a retaining ring installed inside the inner cavity; one end of the retaining ring is fixedly connected to the inner wall of the shell, and the other end of the retaining ring is fixedly connected to the annular body of the device for preventing liquid from being sucked in; the retaining ring includes a second through hole, and the second through hole is coaxial with the first through hole of the annular body;

[0023] The falling film area coil is coiled around the retaining ring and the outer wall of the annular body; and the flooded area coil is located between the flooded area coil and the retaining ring.

[0024] In some embodiments, the housing further comprises:

[0025] A cylindrical body, open at both ends;

[0026] A first cover plate is detachably mounted on one end of the cylinder; the first cover plate is provided with a fluid inlet and a fluid outlet; the fluid outlet is connected to the second through hole of the retaining ring; and

[0027] a second cover plate, detachably mounted on the other end of the cylinder;

[0028] The cylinder, the first cover plate and the second cover plate together form the inner cavity; the fluid inlet is communicated with the portion of the inner cavity of the shell where the falling film zone coil is located.

[0029] In some embodiments, the falling-film heat exchanger further comprises:

[0030] a liquid distributor installed in the inner cavity and located downstream of the fluid inlet.

[0031] The embodiment of the present application also provides a refrigeration system comprising the falling-film heat exchanger provided by any of the technical solutions of the present application.

[0032] The liquid-carrying-preventing device provided by the technical solution has the first through hole and the gas hole, and the gas can flow through the first through hole or the gas hole. The gas hole is located on the wall of the annular body, and the first through hole penetrates the annular body in the axial direction. The directions of the gas hole and the first through hole are different, and the gas hole can divide the flow direction of the gas. The gas entering through the gas hole is blocked by the annular body, and thus condenses on the outer wall of the annular body and flows into the first liquid collecting groove. The volume of the collected liquid is larger, and the liquid is less likely to be carried by the gas. Therefore, the phenomenon of liquid carrying by gas suction is effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings, which are included to provide a further understanding of the present application and are incorporated in and constitute a part of this application, illustrate embodiments of the present application and serve to explain the principles of the present application. In the drawings:

[0034] Figure 1 The figure is a three-dimensional structure diagram of the liquid-carrying-preventing device provided by the embodiment of the present application.

[0035] Figure 2 The figure is a structure diagram of the falling-film heat exchanger provided by the embodiment of the present application.

[0036] Figure 3 The figure is a comparison diagram of the flow improvement effect of the falling-film heat exchanger provided by the embodiment of the present application.

[0037] Figure 4 The figure is a comparison diagram of the central flow uniformity effect of the falling-film heat exchanger provided by the embodiment of the present application.

[0038] Reference signs:

[0039] 1, annular body; 2, shell; 3, baffle ring; 4, falling-film zone coil; 5, full-liquid zone coil; 6, liquid distributor; 11, first through hole; 12, gas hole; 13, first liquid collecting groove; 14, second liquid collecting groove; 15, flow guide groove; 21, inner cavity; 22, cylinder body; 23, first cover plate; 24, second cover plate; 231, fluid inlet; 232, fluid outlet; 31, second through hole; 41, first falling-film zone coil; 42, second falling-film zone coil. DETAILED DESCRIPTION

[0040] The following combination Figures 1-4 The technical solution provided by the present invention is described in more detail. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the parts and steps, the composition of the materials, the numerical expressions and the numerical values ​​described in these embodiments should be interpreted as being merely exemplary and not as limiting. The "multiple" referred to in these embodiments means more than two.

[0041] The terms "first," "second," and similar terms used in this disclosure do not denote any order, quantity, or importance, but are simply used to distinguish one part from another. Terms such as "include" or "comprise" mean that the elements preceding the term include the elements listed after the term, and do not exclude the possibility of also including other elements.

[0042] In the present disclosure, when a specific device is described as being located between a first device and a second device, an intervening device may or may not be present between the specific device and the first device or the second device. When a specific device is described as being connected to another device, the specific device may be directly connected to the other device without an intervening device, or may be not directly connected to the other device but with an intervening device.

[0043] All terms (including technical or scientific terms) used in this disclosure have the same meaning as those understood by one of ordinary skill in the art to which this disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in, for example, general dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an idealized or highly formal sense, unless explicitly defined herein.

[0044] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0045] The dimensions of the various parts shown in the drawings are not drawn in accordance with actual proportions. In the drawings, common structural elements or structural elements of the same type are given the same reference numerals, and their repeated descriptions are appropriately omitted.

[0046] In the related art, the vertical falling film heat exchanger includes a shell arranged vertically and a baffle ring arranged inside the shell. A coil pipe is wound outside the baffle ring. In the refrigerant heat exchange process, the gas to be heat exchanged enters the inside of the baffle ring from the coil pipe along the bottom of the baffle ring, and then flows out of the shell. The inventor finds that when the gas enters the inside of the baffle ring, because the flow direction of the gas intersects with the direction of the liquid refrigerant drop, the liquid refrigerant is easily carried in the gas, the liquid refrigerant is sucked into the outlet of the vertical falling film heat exchanger, the suction gas carries liquid, the refrigerant distribution in the refrigeration system is abnormal, and the refrigerant filling amount required by the refrigeration system is increased. In severe cases, the compressor may even compress the liquid, damaging the compressor. Therefore, the embodiments of the present application provide the following technical solutions to reduce the suction gas carrying liquid phenomenon.

[0047] In the following description of specific embodiments, for the convenience of explanation, the axial direction X of the annular body 1 is marked in Figure 1 and Figure 2 . The X-axis direction represents the up-down direction.

[0048] Figure 1 The three-dimensional structure diagram of the suction gas liquid carrying prevention device provided by the embodiments of the present application is shown in Figure 2 The structure diagram of the falling film heat exchanger provided by the embodiments of the present application is shown in

[0049] Referring to Figure 1 and Figure 2 , some embodiments of the present application provide a suction gas liquid carrying prevention device, which includes an annular body 1, the annular body 1 includes a first through hole 11, a plurality of gas holes 12 and a first liquid collecting groove 13. The first through hole 11 penetrates the axial direction of the annular body 1, each gas hole 12 penetrates the wall of the annular body 1, and each gas hole 12 communicates with the first through hole 11. The first liquid collecting groove 13 is located on the outer wall of the annular body 1, and the first liquid collecting groove 13 is located downstream of at least part of the gas holes 12.

[0050] Referring to Figure 1The annular body 1 comprises a first through hole 11 and gas holes 12. The number of gas holes 12 is more than two, and in some embodiments of the present application, a plurality of gas holes 12 are densely arranged. The first through hole 11 penetrates the axial direction of the annular body 1, and the first through hole 11 is the main flow channel of the gas flow. The gas holes 12 penetrate the wall of the annular body 1, and the first through hole 11 and the gas holes 12 are in communication. The gas outside the first through hole 11 can flow into the first through hole 11 through the gas holes 12. In general, the gas flow in the annular body 1 has two main inflow directions: the first S1 is the inflow through the gas holes 12, that is, it flows basically along the radial direction of the annular body 1. The second S2 is the inflow through one end of the first through hole 11, that is, it flows along the axial direction of the annular body 1. The two gas flows eventually converge into a gas flow S and flow out of the annular body 1. The fluid flowing through the first through hole 11 is more, and the fluid flowing into the first through hole 11 of the annular body 1 through the gas holes 12 is less. By changing the number of gas holes 12, the flow area of a single gas hole 12, the arrangement density of the gas holes 12 and other parameters, the flow ratio of the two gas flows can be effectively adjusted. Because the size of the gas hole 12 is very small, the gas hole 12 plays a role in uniform flow, and the gas flowing through the gas hole 12 is not a large flow, but a plurality of small flows after uniform flow. The ability of small flow to carry liquid is weak, so it greatly reduces the phenomenon of gas carrying liquid, and further improves the phenomenon of gas carrying liquid.

[0051] The annular body 1 is provided with a first liquid collecting groove 13, which is located on the outer wall of the annular body 1 and can be located at the middle position of the axial direction of the annular body 1. Figure 1 、 Figure 2 As shown in the axial direction, the liquid above the first liquid collecting groove 13 will flow downward under its own gravity until it flows into the first liquid collecting groove 13 and converges. The liquid condensed on the outer wall of all gas holes 12 above the first liquid collecting groove 13 can converge into the same first liquid collecting groove 13. The first liquid collecting groove 13 converges the liquid attached to the outer wall of the annular body 1 together to form a larger liquid group to reduce the probability of liquid being carried away by gas and improve the heat exchange effect.

[0052] Continuing to refer to Figure 1 , the first liquid collecting groove 13 is formed in the outer wall of the annular body 1 in a concave manner and is located at the middle position of the axial direction of the annular body 1. The concave part of the first liquid collecting groove 13 is not provided with gas holes 12, which can better contain and collect liquid and will not cause liquid to leak to the inner wall of the annular body 1, nor will it blow away the liquid in the first liquid collecting groove 13 because of the outflow of the gas inside the annular body 1.

[0053] The first liquid collecting groove 13 is configured to surround a circle along the circumference of the outer wall of the annular body 1. In this way, the liquid above the first liquid collecting groove 13 in each direction of the circumference of the annular body 1 can flow into the first liquid collecting groove 13 under the action of its own gravity.

[0054] The gas holes 12 are structures that allow gas to pass through, and are densely distributed on the wall of the annular body 1. The gas holes 12 are not provided at positions where the first liquid collection groove 13, the second liquid collection groove 14 to be described later, and the flow guide groove 15 are located. Except for the above-mentioned areas, the annular body 1 is uniformly arranged with the gas holes 12. The cross-sectional shape of each gas hole 12 has various structural forms, such as a circular shape, an elongated strip shape, and a special shape. The cross-sectional shape of the gas holes 12 in different areas can be the same or different. The circular gas holes 12 are easy to design and manufacture, and have good gas flow characteristics. The elongated strip-shaped gas holes 12 can more conveniently control the direction of gas flow. By changing the length and width of the gas holes 12, different flow control effects can be achieved. The special-shaped gas holes 12 refer to other irregular shapes other than the circular and elongated strip shapes. These special-shaped gas holes 12 are designed according to different application requirements to meet specific gas flow requirements. The shape of the gas holes 12 is usually determined according to the specific application requirements, including the control of the gas flow performance, the pressure drop, and the factors such as the material and manufacturing cost. Different shapes of the gas holes 12 can all achieve the effect of uniform flow, but the shapes of the uniformly flowed fluid are different. In actual application, according to the actual working condition flow, gas density, viscosity, liquid carrying condition, and surface tension, the flow area, distribution density, and shape of the gas holes 12 are determined.

[0055] In some embodiments, the flow area of the gas holes 12 in different areas gradually changes along the axial direction of the annular body 1. Specifically, for example, the closer to the full-liquid area, the smaller the flow area of the gas holes 12. By setting the flow area of the gas holes 12 to be gradually changed, the fluid can be uniformly distributed and passed through the selected area. When the fluid flows through the gas holes 12, the flow speed and pressure can change. By gradually reducing the flow area of the gas holes 12, a larger resistance can be formed in the part close to the full-liquid area, so that the fluid stays in this area for a longer time to achieve better distribution and uniformity. In addition, by reducing the flow area of the gas holes 12, the pressure drop of the fluid can also be increased to adjust the speed and flow of the fluid, to adjust the flow performance of the fluid to meet the requirements of the application.

[0056] Continuing to refer to Figure 1 and Figure 2 In some embodiments, the annular body 1 further includes a second liquid collection groove 14 and a flow guide groove 15. The second liquid collection groove 14 is also located on the outer wall of the annular body 1. The second liquid collection groove 14 is located downstream of the first liquid collection groove 13, one end of the flow guide groove 15 communicates with the first liquid collection groove 13, and the other end of the flow guide groove 15 communicates with the second liquid collection groove 14.

[0057] The liquid collected by the first sump 13 and the liquid outside the gas hole 12 downstream of the first sump 13 are all collected and stored in the second sump 14. The second sump 14 is located at the axial end of the annular body 1. The liquid collected in the second sump 14 will drip under the action of its own gravity to the flooded area.

[0058] The flow guide groove 15 functions to connect the first sump 13 and the second sump 14. A plurality of flow guide grooves 15 are arranged along the circumference of the annular body 1. The number of flow guide grooves 15 is at least two. Each flow guide groove 15 can be a straight groove. The length direction of each flow guide groove 15 is parallel, and is parallel to the axial direction of the annular body 1. Each flow guide groove 15 is dispersedly arranged along the circumferential outer wall of the annular body 1, and can be uniformly arranged. In this way, the fluid in each region of the first sump 13 can be conveniently and quickly flowed into the second sump 14. The first sump 13 functions as a first-stage collection, and the second sump 14 functions as a second-stage collection. Through continuous collection of the liquid, the volume of the liquid is larger, and the liquid will not drip in the form of water droplets, but will flow in the form of water flow to the flooded area. Therefore, the liquid is less likely to be carried away by the gas, and the phenomenon of liquid being sucked up and carried away is effectively reduced.

[0059] Referring to Figure 1 , the second sump 14 is configured to surround a circle along the circumference of the outer wall of the annular body 1. In this way, the liquid in each direction of the circumference of the annular body 1 can flow into the second sump 14 under the action of its own gravity.

[0060] When the gas carrying small liquid droplets passes through the annular body 1 of the gas suction prevention and liquid carrying prevention device, the gas enters the first through hole 11 from the gas hole 12, and most of the liquid droplets are blocked by the annular body 1. The first sump ring arranged collects the liquid droplets falling from the upper part of the gas suction prevention and liquid carrying prevention device into large liquid droplets, and flows along the flow guide groove 15, and finally converges in the second sump 14. Compared with small liquid droplets, large liquid droplets are less likely to be carried by the gas. Therefore, the large liquid can flow down from the gas suction prevention and liquid carrying prevention device and reach the flooded area to continue evaporation.

[0061] The above embodiments provide some embodiments in which only the first collecting trough 13 is provided, and also provide some embodiments in which both the first collecting trough 13 and the second collecting trough 14 are provided. In other embodiments, the annular body 1 is provided with an intermediate collecting trough (not shown) in addition to the first collecting trough 13 and the second collecting trough 14. The intermediate collecting trough is located between the first collecting trough 13 and the second collecting trough 14, that is, downstream of the first collecting trough 13 and upstream of the second collecting trough 14. The liquid collected by the first collecting trough 13 is first collected in the intermediate collecting trough and then flows to the second collecting trough 14. There can be one or more intermediate collecting troughs. If there are multiple intermediate collecting troughs, the intermediate collecting troughs are also arranged sequentially to form an upstream and downstream relationship. If the size of the falling film heat exchanger is very large, then the size of the device used to prevent liquid from being carried over by suction will also be relatively large. In this case, one or more intermediate collecting troughs can be provided to better collect the liquid.

[0062] See also Figure 2 An embodiment of the present invention further provides a falling film heat exchanger, including the device for preventing liquid carryover during air inhalation provided by any of the technical solutions of the present invention. Specifically, the falling film heat exchanger may be a vertical falling film heat exchanger, which can function as an evaporator and is also known as a vertical falling film evaporator. Its compact structure facilitates miniaturization.

[0063] See also Figure 2 In some embodiments, the falling film heat exchanger further comprises a shell 2, a retaining ring 3, a falling film zone coil 4, and a full liquid zone coil 5. The retaining ring 3 is installed inside the inner cavity 21. One end of the retaining ring 3 is fixedly connected to the inner wall of the shell 2, and the other end of the retaining ring 3 is fixedly connected to the device for preventing air suction and liquid entrainment; the retaining ring 3 includes a second through hole 31, and the second through hole 31 is coaxial with the first through hole 11. The falling film zone coil 4 is coiled around the outer wall of the retaining ring 3 and the device for preventing air suction and liquid entrainment; the device for preventing air suction and liquid entrainment is located between the full liquid zone coil 5 and the retaining ring 3.

[0064] The housing 2 can be a detachable housing or a non-detachable housing. In the embodiment of the present invention, a detachable housing is used as an example. Figure 2 The housing 2 includes a first cover plate 23, a second cover plate 24, and a cylindrical body 22 with both ends open. The first cover plate 23 is detachably mounted on one end of the cylindrical body 22, and the second cover plate 24 is detachably mounted on the other end of the cylindrical body 22. The first cover plate 23, the second cover plate 24, and the cylindrical body 22 together form an inner cavity 21.

[0065] The first cover plate 23 is provided with a fluid inlet 231 and a fluid outlet 232. The retaining ring 3 is located inside the inner cavity 21 and is connected to the fluid outlet 232. The falling film zone coil 4 is wound around the retaining ring 3 and the outer wall of the device for preventing liquid from being sucked into the air, and the falling film zone coil 4 is also located inside the inner cavity 21. The fluid inlet 231 is connected to the area of ​​the inner cavity 21 where the falling film zone coil 4 is located.Figure 2 The falling-film heat exchanger further comprises a liquid distributor 6 located downstream of the fluid inlet 231. The falling-film zone coil 4 is divided into two parts: a first falling-film zone coil 41 and a second falling-film zone coil 42. The first falling-film zone coil 41 is also referred to as the upper falling-film zone coil, and the second falling-film zone coil 42 is also referred to as the lower falling-film zone coil. The first falling-film zone coil 41 is located upstream of the second falling-film zone coil 42, and the second falling-film zone coil 42 is located upstream of the flooded zone coil 5.

[0066] The first cover plate 23, the second cover plate 24 and the barrel 22 of the shell 2 can be made of metal materials such as carbon steel and stainless steel. In this way, the shell 2 has sufficient strength and rigidity, strong load capacity, and can play a good supporting and protective effect, so that the falling-film heat exchanger can operate stably and safely. The first cover plate 23 and the second cover plate 24 of the shell 2 are detachably connected with the barrel 22, so that the falling-film zone coil 4 and the flooded zone coil 5 inside the falling-film heat exchanger can be conveniently cleaned and replaced.

[0067] When the falling-film heat exchanger operates under refrigeration conditions, the liquid refrigerant enters the falling-film heat exchanger through the fluid inlet 231 and flows to the falling-film zone coil 4 after passing through the liquid distributor 6. The remaining liquid that has not been evaporated flows to the flooded zone coil 5 and is evaporated. All the gas flows from the bottom of the baffle 3 and the gas hole 12 to the fluid outlet 232, and then flows out of the falling-film heat exchanger.

[0068] The baffle 3 is a circular ring, and is located in the inner cavity 21 of the shell 2 and in the falling-film zone. The baffle 3 is fixedly connected with the liquid-carrying-prevention device, and the two are in airtight connection. The airtight connection means that the baffle 3 and the liquid-carrying-prevention device are connected by appropriate sealing measures, so that the fluid does not leak from the connection between the baffle 3 and the liquid-carrying-prevention device. The airtight connection can ensure that the fluid in the baffle 3 is smoothly transported to the position where the liquid-carrying-prevention device is located. Different sealing materials and connection methods can be used to achieve airtight connection, such as rubber gaskets, sealing rings, threaded connections, flange connections, etc. These connection methods are all detachable connections, and when the liquid-carrying-prevention device fails or is blocked, the liquid-carrying-prevention device can be replaced.

[0069] The sum of the axial length of the annular body 1 and the axial length of the baffle 3 is equal to the axial length of the falling-film zone coil 4, so as to improve the heat transfer effect and mass transfer effect. Referring to Figure 2 The end of the annular body 1 away from the baffle 3 is substantially flush with the bottom end of the falling-film zone coil 4.

[0070] The falling film zone is an important zone of the heat exchanger, which is used for the gas and liquid to be contacted and heat transferred sufficiently. In the falling film zone, the gas and liquid form a thin film by the extrusion of the coil wall surface and the surface tension, which is called falling film. The design and structure of the falling film zone have important influence on the heat transfer and mass transfer effect.

[0071] The sum of the axial length of the annular body 1 and the retaining ring 3 is about equal to the axial length of the falling film zone coil 4, which can make the length of the falling film zone moderate to meet the requirements of heat transfer and mass transfer. The coil is surrounded by the outer wall of the retaining ring 3 and the annular body 1, which promotes the gas-liquid mixing and the improvement of the heat transfer effect by increasing the gas-liquid contact area and the cracking liquid flow. Meanwhile, the annular body 1 and the retaining ring 3 also make the gas-liquid distribution more uniform, improve the flow characteristics of the fluid and the heat transfer effect, and improve the working efficiency of the falling film zone.

[0072] The technical effects of the embodiment of the application are described in detail by comparison and analysis as follows.

[0073] Referring to Figure 3 , Figure 3 The right half part is a schematic view of the gas deflection with the liquid entrainment prevention device added. Figure 3 The left half part is a schematic view of the gas deflection without the liquid entrainment prevention device added. Figure 3 As can be seen from the left and right parts of Figure 2 , the area A corresponds to the area where the liquid entrainment prevention device is located. If the liquid entrainment prevention device is not set, the gas directly defluxes into the second through hole 31 of the retaining ring 3 and then flows up to the fluid outlet 232 in , that is, from the area where A3 flows to A3', in this process, the deflection angle of the gas flow A3' at the falling film zone coil 4 is large, and all the gas flows will appear deflection phenomenon. When the deflection is large to a certain extent, the falling film will deviate from the coil, which causes the liquid distribution on the surface of the coil to be insufficient, and the falling film evaporation heat transfer performance is poor. Moreover, since the liquid between the falling film zone coils 4 flows vertically, the gas flow flowing along the horizontal direction will deviate the liquid, which makes the liquid unable to flow to the lower heat exchange pipe, which makes the heat exchange effect of the falling film heat exchanger worse.

[0074] Figure 3If the anti-liquid-carrying device is arranged inside the falling-film heat exchanger, in region A, part A1' of the gas flow A1 will flow into the second through hole 31 of the baffle ring 3 through the gas hole 12, and the amount of the gas flow is determined by the flow area of the gas hole 12. The remaining gas flow A1" enters the first through hole 11 from the bottom of the anti-liquid-carrying device, and then flows into the second through hole 31 communicating with the first through hole 11. From the above flow process, it can be seen that the gas can enter the first through hole 11 of the annular body 1 from the side and the bottom of the annular body 1 at the same time, so that the fluid flow entering the baffle ring 3 is more uniform, the angle of the fluid deflection is smaller, and the deflection phenomenon can be reduced by 20%-30% by adopting the technical scheme of the embodiment of the present application, so that the liquid-carrying phenomenon can be effectively reduced or even avoided.

[0075] Referring to Figure 4 , the effect of the anti-liquid-carrying device on reducing the flow rate at the center of the baffle ring 3 will be described below. Figure 4 The right half is a schematic view of the flow rate at the center of the baffle ring 3 with the anti-liquid-carrying device added. Figure 4 The left half is a schematic view of the flow rate at the center of the baffle ring 3 without the anti-liquid-carrying device added, but the length of the baffle ring 3 is extended to be the same as that of the anti-liquid-carrying device on the right half. Figure 4 As can be seen by comparing the left and right halves of

[0076] If the anti-liquid-carrying device is not arranged inside the falling-film heat exchanger, i.e. Figure 4 The left half shows that the gas flow B4 enters the second through hole 31 of the baffle ring 3 after being turned at the bottom of the baffle ring 3, i.e. the gas flow B6. The gas flow B4, the gas flow B5 and the gas flow B6 are always the same gas flow, so the flow rate at the center of the baffle ring 3 is particularly high. The gas flow B6 is always a gas flow, so the flow rate is particularly high. Finally, a high flow rate region will be generated at the center of the annular body 1, further increasing the risk of liquid-carrying by gas suction from the full-liquid region.

[0077] Continuing to refer to Figure 4 If the anti-liquid-carrying device is arranged inside the falling-film heat exchanger, i.e. Figure 4 The right half shows that the gas flow is divided into two, one is the gas flow B1, and the other is the gas flow B2. The gas flow B1 enters the first through hole 11 after being uniformly distributed through the gas hole 12. The gas flow B2 enters the first through hole 11 after being turned at the bottom of the annular body 1. Since the gas flow B1 enters the first through hole 11 after being uniformly distributed, the flow rate of the gas flow is reduced. The gas flow B3 is obtained by the combination of the uniformly distributed B1 and the turned B2, and the maximum flow rate at the center of the gas flow B3 is much smaller than that of the gas flow B6 introduced above, so the risk of liquid-carrying by gas suction from the full-liquid region is greatly reduced.

[0078] The technical scheme, by setting the annular body 1, effectively optimizes the structure and performance of the falling film area, reduces the maximum flow velocity at the center of the baffle ring 3, weakens the flow deviation phenomenon, improves the heat and mass transfer effect, and improves the overall performance of the falling film heat exchanger.

[0079] The embodiment of the present application also provides a refrigeration system comprising the falling film heat exchanger provided by any of the technical schemes of the present application.

[0080] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship 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 device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the protection scope of the present application. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0081] In the description of the present application, each technical feature can be combined with other technical features as far as possible.

[0082] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A device for preventing liquid from being sucked into the air, characterized in that: include: An annular body (1) comprises a first through hole (11), a plurality of air holes (12) and a first liquid collecting trough (13); the first through hole (11) passes through the annular body (1) in an axial direction, the plurality of air holes (12) all pass through the wall of the annular body (1) and are in communication with the first through hole (11); the first liquid collecting trough (13) is located on the outer wall of the annular body (1) and is located downstream of at least part of the air holes (12); The annular body (1) further comprises: a second liquid collecting trough (14), located on the outer wall of the annular body (1) and downstream of the first liquid collecting trough (13); as well as A guide groove (15), one end of the guide groove (15) is connected to the first liquid collecting groove (13), and the other end of the guide groove (15) is connected to the second liquid collecting groove (14).

2. The device for preventing liquid from being sucked into the air according to claim 1, wherein: The first liquid collecting trough (13) is configured to surround the outer wall of the annular body (1) in a circle along the circumference; and / or the second liquid collecting trough (14) is configured to surround the outer wall of the annular body (1) in a circle along the circumference.

3. The device for preventing liquid from being sucked into the air according to claim 1, wherein: The length direction of the guide groove (15) is parallel to the axial direction of the annular body (1), and the guide groove (15) is arranged on the outer wall of the annular body (1).

4. The device for preventing liquid from being sucked into the air according to claim 1, wherein: The number of the guide grooves (15) is at least two, and each of the guide grooves (15) is dispersedly arranged along the circumference of the annular body (1).

5. The device for preventing liquid from being sucked into the air according to any one of claims 1 to 4, characterized in that: The first liquid collecting trough (13) is located in the axial middle portion of the annular body (1).

6. The device for preventing liquid from being sucked into the air according to claim 1, wherein: The second liquid collecting trough (14) is located at an axial end of the annular body (1).

7. The device for preventing liquid from being sucked into the air according to any one of claims 1 to 4, characterized in that: The cross-sectional shape of the air hole (12) is one of the following: circular, elongated, or irregular.

8. The device for preventing liquid from being sucked into the air according to any one of claims 1 to 4, characterized in that: Along the axial direction of the annular body (1), the flow area and / or arrangement density of each of the air holes (12) are the same or gradually change.

9. The device for preventing liquid from being sucked into the air according to claim 1, wherein: The annular body (1) further comprises: The middle liquid collecting trough is located on the outer wall of the annular body (1) and between the first liquid collecting trough (13) and the second liquid collecting trough (14).

10. A falling film heat exchanger, characterized in that: The invention comprises the device for preventing liquid from being sucked into the air as described in any one of claims 1 to 9.

11. The falling film heat exchanger according to claim 10, characterized in that Also includes: A housing (2) including an inner cavity (21); A retaining ring (3) is installed inside the inner cavity (21); one end of the retaining ring (3) is fixedly connected to the inner wall of the shell (2), and the other end of the retaining ring (3) is fixedly connected to the annular body (1) of the device for preventing liquid from being sucked in; the retaining ring (3) includes a second through hole (31), and the second through hole (31) is coaxial with the first through hole (11) of the annular body (1); The falling film zone coil (4) is coiled around the retaining ring (3) and the outer wall of the annular body (1); and The full liquid area coil (5) is located between the full liquid area coil (5) and the retaining ring (3).

12. The falling film heat exchanger according to claim 11, characterized in that The housing (2) further comprises: A cylindrical body (22) with both ends open; A first cover plate (23) is detachably mounted on one end of the cylinder (22); the first cover plate (23) is provided with a fluid inlet (231) and a fluid outlet (232); the fluid outlet (232) is communicated with the second through hole (31) of the retaining ring (3); and a second cover plate (24) detachably mounted on the other end of the cylinder (22); The cylinder (22), the first cover plate (23) and the second cover plate (24) together form the inner cavity (21); the fluid inlet (231) is connected to the portion of the inner cavity (21) of the shell (2) where the falling film zone coil (4) is located.

13. The falling film heat exchanger according to claim 12, characterized in that Also includes: The liquid distributor (6) is installed in the inner cavity (21) and is located downstream of the fluid inlet (231).

14. A refrigeration system, characterized in that: It comprises the falling film heat exchanger according to any one of claims 10 to 13.

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