Falling film evaporator

Abstract

A falling film evaporator (100) is provided, the housing (101) of which accommodates heat exchange tubes (304), a perforated plate (205), and spray tubes (202), the perforated plate (205) being disposed between the spray tubes (202) and the heat exchange tubes (304), such that the refrigerant sprayed from the spray tubes (202) is sprayed onto the surfaces of the heat exchange tubes (304) by distribution through the perforated plate (205), and the spray openings (301) on the spray tubes (202) have a strip shape, and the extension direction of the openings is perpendicular to the length of the spray tubes (202). By configuring the length of the spray tubes (202) to be substantially perpendicular to the length of the heat exchange tubes (304), the refrigerant sprayed from the spray openings (301) flows substantially in the length direction of the housing (101), the refrigerant flow path is lengthened, and uneven spraying onto the surfaces of the heat exchange tubes (304) is avoided.

Description

[Technical field]

[0001] The present application relates to the technical field of falling film evaporators. [Background technology]

[0002] Falling film evaporators generally use a refrigerant distributor to distribute the refrigerant on the surface of the heat exchange tubes in the heat exchange tube bundle to form a liquid film for evaporation. They utilize the mechanism of thin film evaporation from the heat exchange tube surface, and have the advantages of high heat transfer efficiency and low refrigerant input, and have become the focus of research in the refrigeration and air conditioning industry in recent years. However, the uniformity of refrigerant distribution on the heat exchange tube bundle in the evaporator is the main factor limiting the heat exchange performance of the evaporator. The state of the refrigerant entering the refrigerant distributor is generally in gas phase and liquid phase, and if these two phases of the refrigerant are not uniformly distributed on the heat exchange tube bundle of the falling film evaporator, the result will be that the refrigerant distributor will supply too much refrigerant to some parts of the heat exchange tubes and too little refrigerant to other parts of the heat exchange tubes, resulting in the phenomenon of "dry spots", which leads to a decrease in the overall heat exchange performance of the falling film evaporator. Summary of the Invention [Means for solving the problem]

[0003] SUMMARY OF THE PRESENT APPLICATION It is an object of the present application to provide an improved falling film evaporator capable of uniformly distributing refrigerant to the heat exchange tubes.

[0004] In order to achieve the above object, the present application provides a falling film evaporator, which includes a housing, a heat exchange tube, a perforated plate, a spray tube, and a liquid inlet tube. The housing has a receiving cavity. Longitudinal The housing Longitudinal The perforated plate is disposed above the heat exchange tubes, the perforated plate having a plurality of distribution holes. The spray tube is disposed above the perforated plate, the spray tube having a plurality of spray ports, the spray ports being the same as the spray tube. LongitudinalThe heat exchange tubes, the perforated plate, and the spray ports are configured to be capable of spraying refrigerant toward the perforated plate. The liquid inlet tubes are in fluid communication with the spray tubes such that refrigerant flowing through the liquid inlet tubes can flow into the spray tubes. The heat exchange tubes, the perforated plate, and the spray tubes are all disposed within the receiving cavity. Longitudinal The housing Longitudinal is substantially perpendicular to the

[0005] In the falling film evaporator described above, the perforated plate Longitudinal is the housing Longitudinal The spray port is the same as the spray port in that the refrigerant is sprayed toward the perforated plate and then the refrigerant is Longitudinal The system is configured to allow the input voltage to flow to the

[0006] In the falling film evaporator described above, the bottom of the spray tube has an arcuate end face, which protrudes towards the perforated plate, and the spray ports are strip-shaped, with at least a portion of the spray ports being located on the arcuate end face.

[0007] In the falling film evaporator described above, the spray tubes are Longitudinal The nozzle has two extensions extending from the nozzle hole to the nozzle tip, the ends of the extensions having arcuate end faces protruding outward, the spray port having a rectangular shape, and at least a portion of the spray port being disposed on the arcuate end faces.

[0008] In the above-mentioned falling film evaporator, the cross section of the spray tube has a flat elliptical shape, the two extensions are respectively located at the left and right ends of the spray tube, the spray port is strip-shaped, and the spray port extends from the bottom of the spray tube to the arc-shaped end faces at the left and right ends of the spray tube, respectively.

[0009] In the falling film evaporator described above, the cross section of the spray tube has an inverted "Y" shape, the two extensions are separately arranged at the bottom of the spray tube and extend diagonally downward, the spray ports are strip-shaped, and at least a part of the spray ports is arranged on the arc-shaped end face.

[0010] In the above-mentioned falling film evaporator, a plurality of the aforementioned spray tubes are disposed in the falling film evaporator, and the upper ends of the plurality of spray tubes are in communication with each other, such that the plurality of spray tubes are in fluid communication with each other.

[0011] In the falling film evaporator described above, the number of spray tubes is an even number, and the spray tubes are symmetrically distributed with respect to the liquid inlet tube.

[0012] The above-mentioned falling film evaporator further includes a liquid inlet box, which is disposed between the liquid inlet pipe and the spray pipe, so that the liquid inlet pipe and the spray pipe can be fluidly connected to each other through the liquid inlet box.

[0013] The above-mentioned falling film evaporator further comprises a cover plate, the cover plate is disposed at the upper part of the spray tube, and the two side edges of the cover plate extend towards the perforated plate and are directly or indirectly connected to the two side edges of the perforated plate in a sealing manner.

[0014] In the falling film evaporator of the present application, the spray tube Longitudinal is the evaporator housing Longitudinal This configuration allows the refrigerant sprayed from the spray ports to be substantially perpendicular to the housing. Longitudinal Thus, the flow path of the refrigerant sprayed from the spray port is extended, and the problem of the refrigerant being sprayed unevenly on the surface of the heat exchange tube due to the flow of the sprayed refrigerant being obstructed is avoided. [Brief description of the drawings]

[0015] [Figure 1]FIG. 1 is a schematic diagram of a three-dimensional structure of a falling film evaporator 100 in an embodiment of the present application. [Diagram 2] FIG. 2 is a structural schematic diagram of some of the components disposed inside the housing 101 of the falling film evaporator 100 shown in FIG. [Diagram 3] FIG. 2 is a radial cross-section of the falling film evaporator 100 shown in FIG. 1 at the position of the liquid inlet pipe 102. [Figure 4] FIG. 4 is an enlarged partial view of the falling film evaporator 100 shown in FIG. 3 in the region of the spray tubes 202. [Diagram 5] FIG. 3 is a schematic diagram of the three-dimensional structure of the spray tube 202 of FIG. 2. [Figure 6] A cross section of the spray tube 202 shown in FIG. 5 at the location of the spray port 301 is shown. [Figure 7] The travel path of the refrigerant after being sprayed from the spray pipe 202 in the positional configuration shown in FIG. 4 is shown. [Figure 8A] A first embodiment of a cross-sectional shape of the spray tube 202 at the location of the spray port 301 is shown. [Figure 8B] A second embodiment of a cross-sectional shape of the spray tube 202 at the location of the spray port 301 is shown. [Figure 9] FIG. 2 shows an axial cross-section of a falling film evaporator with two spray tubes 202 at the position of the liquid inlet tube 102. [Figure 10A] 1 shows a first embodiment of the structure of two spray tubes in a falling film evaporator. [Figure 10B] 2 shows a second embodiment of the structure of two spray tubes in a falling film evaporator. [Figure 10C] 3 shows a third embodiment of the structure of two spray tubes in a falling film evaporator. [Figure 10D] 4 shows a fourth embodiment of the structure of two spray tubes in a falling film evaporator. [Figure 11] 1 shows a comparative embodiment of the position configuration of the spray tubes inside a falling film evaporator. [Figure 12]FIG. 12 shows an axial cross-sectional view of a falling film evaporator with the spray tube configuration shown in FIG. 11 at the liquid inlet tube position. [Figure 13] FIG. 12 shows a radial cross-section of a falling film evaporator with the spray tube configuration shown in FIG. 11 at the liquid inlet tube. [Figure 14] 14 shows the path of the refrigerant after it is sprayed from the spray pipe shown in FIG. 13. [Figure 15] 15 shows the flow velocity of the coolant passing through different positions across the width of the perforated plate shown in FIG. 14. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Various specific embodiments of the present application are described below with reference to the drawings that form a part of this specification. Although directional terms such as "front", "rear", "upper", "lower", "left", "right", "top", "bottom", etc. are used in this application to describe various illustrative structural parts and elements of the present application, it should be understood that these terms are used herein for convenience of description only and are determined based on the illustrative orientations shown in the figures. Because the embodiments disclosed herein may be configured in different orientations, these directional terms are merely exemplary and should not be considered as limiting.

[0017] 1 shows a three-dimensional structure of a falling film evaporator 100 in an embodiment of the present application. As shown in FIG. 1, the falling film evaporator 100 includes a housing 101, a liquid inlet tube 102, a gas suction tube 104, and a tube sheet 103. The housing 101 is substantially cylindrical, and the tube sheet 103 is a tube sheet of the housing 101. Longitudinal The liquid inlet tube 102 is disposed in the upper portion of the housing 101 and is configured to introduce refrigerant into the interior of the housing 101. The gas suction tube 104 is also disposed in the upper portion of the housing 101 and is configured to exhaust gaseous refrigerant from the housing 101.

[0018] FIG. 2 is a structural schematic diagram of some of the components disposed inside the housing 101 of the falling film evaporator 100 shown in FIG. 1, and for convenience of explanation, the liquid inlet tube 102 disposed outside the housing 101 is also included in FIG. 2. As shown in FIG. 2, the falling film evaporator 100 further includes a spray tube 202, a perforated plate 205, and a heat exchange tube bundle 201 (shown in FIG. 3) disposed in the receiving cavity of the housing 101. The spray tube 202 is disposed below the liquid inlet tube 102, the perforated plate 205 is disposed below the spray tube 202, and the heat exchange tube bundle 201 is disposed below the perforated plate 205. The spray tube 202 is substantially in the form of a tube with both ends closed. An inlet 206 configured to be in fluid communication with the liquid inlet tube 102 is provided at the top of the spray tube 202. A plurality of spray ports 301 are provided at the bottom of the spray tube 202 and are configured to spray the refrigerant entering the spray tube 202 onto a perforated plate 205 below the spray tube 202. The perforated plate 205 is substantially in the shape of a long strip. Longitudinal Housing 101 Longitudinal The perforated plate 205 is provided with a number of distribution holes 305, which are configured to redistribute the refrigerant sprayed on the perforated plate 205, so that the refrigerant can be uniformly distributed on the heat exchange tube bundle 201 below the perforated plate 205. Side stop plates 204 are also provided on the left and right opposing surfaces of the perforated plate 205, and these two side stop plates 204 extend downward perpendicularly to the perforated plate 205, so that these two side stop plates 204 and the perforated plate 205 together form a receiving space that is open downward. In the embodiment shown in FIG. 2, all of the distribution holes 305 of the perforated plate 205 are circular. In other embodiments, the distribution holes 305 may be of another shape, such as, for example, an ellipse, a square, or a diamond. Furthermore, the number of the spray tubes 202 is preferably 1 to 100, and more ... Longitudinal is the hole plate 205 Longitudinal That is, the spray pipe 202 is substantially perpendicular to the Longitudinal is the same as the width direction of the perforated plate 205. Longitudinal is the hole plate 205 Longitudinal The spray tube 202 is perpendicular to the hole plate 205, but the positional relationship between these two components is not limited within a certain range. Longitudinal As a result, the refrigerant sprayed from the spray tube 202 is directed toward the center of the perforated plate 205. Longitudinal From the center position of the hole plate 205 Longitudinal It can be sprayed evenly on both sides.

[0019] The falling film evaporator 100 further comprises a liquid inlet box 203 disposed between the spray tube 202 and the liquid inlet tube 102, and a cover plate 302 disposed on the upper part of the spray tube 202. The liquid inlet box 203 is Longitudinal In order to allow pre-dispensing of refrigerant to the spray tube 202, Longitudinal 205 and is configured to establish fluid communication between the liquid inlet tube 102 and the inlet 206 of the spray tube 202. The cover plate 302 is Longitudinal The cover plate 302 extends upward and the two side edges of the cover plate 302 extend downward, so that the cover plate 302 looks like an inverted "U" shaped structure. The cover plate 302 is disposed between the liquid inlet box 203 and the spray tube 202, and has an opening between the liquid inlet box 203 and the spray tube 202 to ensure communication between the liquid inlet box 203 and the spray tube 202. The spray port 301 on the spray tube 202 is disposed in the cavity between the cover plate 302 and the perforated plate 205, so that the refrigerant sprayed from the spray port 301 can be reliably guided by the cover plate 302 to flow toward the perforated plate 205.

[0020] Figure 3 is a radial cross-sectional view of the falling film evaporator 100 shown in Figure 1 at the position of the liquid inlet tube 102. As shown in Figure 3, the housing 101 includes two heat exchange tube bundles 201, one of which is disposed in the accommodation space formed by the perforated plate 205 and the two side stop plates 204, and the other of which is disposed at the bottom of the accommodation cavity of the housing 101, and each of the heat exchange tube bundles 201 includes a number of heat exchange tubes 304.

[0021] 4 is a partial enlarged view of the falling film evaporator 100 shown in FIG. 3 in the area of ​​the spray tube 202. As shown in FIG. 4, a plurality of spray ports 301 are provided in the spray tube 202. Longitudinal The cover plate 302 is disposed at the bottom of the spray tube 202 with a space therebetween. The cover plate 302 is connected to the side stop plate 204 in a sealed manner, thereby ensuring that all of the refrigerant sprayed from the spray ports 301 flows toward the perforated plate 205 and is distributed on the heat exchange tube bundle 201 through the distribution holes 305 of the perforated plate for heat exchange. In another embodiment, the cover plate 302 may be directly connected to the two side edges of the perforated plate 205 in a sealed manner in the width direction. Such a configuration can also ensure that all of the refrigerant sprayed from the spray ports 301 flows toward the perforated plate 205.

[0022] 5 shows the three-dimensional structure of the spray tube 202 shown in FIG. 2. As shown in FIG. 5, a plurality of spray ports 301 are provided at the bottom of the spray tube 202. Each spray port 301 has a rectangular shape and extends from the bottom of the spray tube 202 toward two side walls. Due to the extension direction of the opening of the spray port 301, the plane on which each spray port 301 exists is the same as the plane of the spray tube 202. Longitudinal The spray ports 301 are parallel to each other and are perpendicular to the spray tube 202. Longitudinal are spaced apart.

[0023] FIG. 6 shows a cross section of the spray tube 202 shown in FIG. 5 at the position of the spray port 301. As shown in FIG. 6, the upper part of the cross section of the spray tube 202 is substantially rectangular, while the lower part is substantially a semicircular arc. The spray port 301 is disposed at the position of the semicircular arc at the bottom of the spray tube 202, as shown by the white background at the lower part of the spray tube in FIG. 6. When the refrigerant is sprayed out from the spray port 301 of the spray tube 202, the refrigerant spreads outward uniformly in the opening direction of the spray port 301. From FIG. 5, it can be seen that the refrigerant sprayed from the spray port 301 has a constant flow rate, and since the spray port 301 has a long and thin strip shape, the refrigerant can be uniformly sprayed outward from the spray tube 202. Longitudinal It can be seen that the sprayed refrigerant hardly spreads out. Most of the refrigerant is sprayed only in the width direction of the spray pipe 202.

[0024] 7 shows an axial cross-sectional view of the housing 101 of the falling film evaporator 100 at the position of the liquid inlet tube 102, with the arrows indicating the path of travel of the refrigerant after being sprayed from the spray tubes 202. As shown in FIG. 7, the cover plate 302, the perforated plate 205 and the side stop plate 204 have the same structure as the housing 101. Longitudinal 301, all of which are substantially the same length and all of which end up to the tube sheet 103. Influenced by the shape of the opening of the spray ports 301 and the pressure difference between the inside and outside of the spray tubes 202, the refrigerant sprayed from the spray tubes 202 is sprayed in the area below the spray ports 301 until it reaches the perforated plate 205. Since the refrigerant has a high initial velocity when it is sprayed from the spray ports 301, the refrigerant still maintains a high velocity after it is sprayed up to the perforated plate 205, and therefore the refrigerant flows down the perforated plate 205 towards both ends of the perforated plate 205. Longitudinal The perforated plate 205 is of an appropriate length, so that the velocity of the refrigerant decreases as it continues to flow, and when it moves close to the tube sheets 103 on both sides, the velocity of the refrigerant is already so slow that no vortex is formed at the tube sheets 103 on both sides, thereby distributing the refrigerant evenly on the surface of the perforated plate. Longitudinal As the refrigerant moves from the distribution holes 305 in the perforated plate 205 to the heat exchange tube bundle 201 below the perforated plate 205, the refrigerant is able to flow through the distribution holes 305 in the perforated plate 205 toward the heat exchange tube bundle 201, such that the refrigerant is evenly distributed over the multiple heat exchange tubes 304 in the heat exchange tube bundle 201.

[0025] 8A and 8B respectively show cross sections of two other embodiments of the spray tube 202 at the spray port location. In these two embodiments, the cross-sectional shape of the spray tube 202 is different from the cross-sectional shape of the spray tube 202 shown in FIG. 6. The cross section of the spray tube 202 shown in FIG. 6 is generally longer in the vertical direction and has a narrower width. This is specifically manifested as an upper portion being rectangular, while a lower portion being a semicircular arc. However, narrowing the width of the cross section of the spray tube 202 requires the perforated plate 205 to be spaced apart. Longitudinal Therefore, in order to successfully move the refrigerant sprayed from the spray tube 202 to a position close to the tube sheet 103, in some embodiments of the present application, the spray tube 202 is arranged in a width direction of the spray tube 202 (i.e., the width of the housing 101). Longitudinal ) to form two extensions 801, and the spray port is at least partially disposed on the extensions, thus forming a Longitudinal This helps to increase the spray distance of the coolant in the

[0026] As shown in Fig. 8A, the cross section of the spray tube 202 has a flat elliptical shape, with flat straight sides on the upper and lower sides, and two extensions 801 are respectively located on the left and right sides of the spray tube 202, and the end of each extension 801 has an outwardly protruding arc-shaped end surface 501. Due to the structure just described, the cross section of the spray tube 202 has a longer span in the lateral direction. Fig. 8A shows the location of the spray port 301 in the white part of the cross section of the spray tube. The spray port 301 is in the shape of a strip and is located in the lower half of the spray tube 202, extending from the bottom of the spray tube 202 to the arc-shaped end surfaces 501 on both sides.

[0027] The cross section of the spray tube 202 shown in FIG. 8B has an inverted "Y" shape. The two extension parts 801 are disposed on either side of the bottom of the spray tube 202 and extend diagonally downward, so that a certain angle A is formed between the two extension parts 801. In some embodiments, the angle A is 60° or more, so that the width of the spray tube 202 is expanded to a greater extent. From FIG. 8B, it can be seen that the end of each extension part 801 has an outwardly protruding arc-shaped end surface 501, and the spray ports 301 are substantially disposed on these two arc-shaped end surfaces 501. FIG. 8B shows how the two spray ports 301 are disposed on the same cross section of the spray tube 202. The spray tube 202 has a plurality of extension parts 801, each of which has a plurality of extension parts 801. Longitudinal 8B, a row of spray ports 301 are spaced apart on each side of the arcuate end surface 501. Thus, two rows of spray ports 301 are located on a single spray tube 202 as shown in FIG. Longitudinal This significantly increases the refrigerant spray distance in the

[0028] 9 is an axial cross-sectional view of a falling film evaporator with two spray tubes 202 at the position of the liquid inlet tube 102. As shown in FIG. 9, the longer length of the housing 101 can be accommodated and the Longitudinal In order to extend the spray distance of the spray tube 202, the embodiment shown in FIG. 9 uses two spray tubes 202 arranged side by side inside the evaporator housing 101. The cross section of the spray tube 202 can be any of the shapes shown in FIG. 6, FIG. 8A, and FIG. 8B. One liquid inlet box 203 is provided on each spray tube 202, so that the refrigerant is discharged from the spray tube 202 before entering the spray tube 202. LongitudinalIn order to promote uniform distribution of the refrigerant, the liquid inlet tube 102 is disposed at the axial center position of the housing 101, and the two spray tubes 202 are disposed in parallel at the same height above the perforated plate 205, and are disposed symmetrically on the left and right sides of the liquid inlet tube 102. As shown in FIG. 9, the gap between the vertical center axis of either one of the two spray tubes 202 and the center axis of the liquid inlet tube 102 is L, and the distance between the vertical center axis of either one of the two spray tubes 202 and the tube sheet 103 on the corresponding side is also L. The symmetrical structural configuration of the spray tubes 202 just described helps to spray the refrigerant uniformly on the surface of the perforated plate 205.

[0029] To achieve the above-mentioned configuration of the spray tube 202, the liquid inlet tube 102 of the embodiment shown in Figure 9 is configured as follows: One end of the liquid inlet tube 102 close to the refrigerant inlet extends vertically. Before extending into the housing 101, the liquid inlet tube 102 bifurcates into two branches, each of which is connected to the housing 101. Longitudinal Above the positions of the two spray pipes 202, the two branch pipes are respectively formed into vertical corners, thereby extending vertically downward until they enter the interior of the housing 101, thereby respectively feeding into two liquid inlet boxes 203 disposed above the two spray pipes 202. With the configuration just described, the refrigerant enters the liquid inlet tube 102 and then bifurcates into two paths, flowing into two different spray tubes 202, respectively.

[0030] In some embodiments, the number of spray tubes 202 may be set to an even number greater than two to accommodate falling film evaporators with longer housings. Setting the number of spray tubes 202 to an even number facilitates uniform spray tube distribution on both sides of the liquid inlet tube 102, such that the refrigerant flowing through the liquid inlet tube 102 is evenly distributed among the spray tubes 202.

[0031] 10A-10D show another embodiment in which two spray tubes 202 are placed together in a falling film evaporator.

[0032] As shown in FIG. 10A, two spray pipes 202 are arranged side by side at the same height and share one liquid inlet box 203. The liquid inlet box 203 has a wide cross section, so that two side portions in the width direction of the liquid inlet box 203 can be respectively connected to the upper ends of the two spray pipes 202 and communicate with the upper ends of the two spray pipes 202. In the configuration just described, the fluid communication with the two spray pipes 202 can be realized simultaneously by the shared liquid inlet box 203 using one straight liquid inlet pipe 102. Therefore, the housing 101 needs to have only one opening for the liquid inlet pipe 102 to pass through, which simplifies the structure of the liquid inlet pipe 102 and the housing 101.

[0033] Figure 10B shows another embodiment of the double spray pipe structure. As shown in Figure 10B, two spray pipes 202 are arranged parallel to each other at the same height, and the cross section of each spray pipe 202 is substantially circular. The circular cross section design promotes uniform distribution of the refrigerant in the direction of the spray port.

[0034] Figures 10C and 10D show a structure in which two spray tubes 202 are arranged at a certain angle in the falling film evaporator. As shown in Figures 10C and 10D, in the same cross section of the falling film evaporator, the central axes of the two spray tubes 202 form a certain angle B of 60° or more. This setting of the angle B is the falling film evaporator housing. LongitudinalIt helps to extend the spray distance of the spray pipe 202 in the same cross section of the falling film evaporator. In order to make the central axes of the two spray pipes 202 in the same cross section of the falling film evaporator form a certain angle B, the liquid inlet pipe 102 is configured such that one end of it extends vertically downward and then bifurcates into two branches before communicating with the spray pipe 202, and the two branches extend horizontally in opposite directions. Above the two spray pipes 202, the two branches form an obtuse angle, so that the two branches extend diagonally downward away from each other until they respectively connect with the two spray pipes 202.

[0035] As can be seen from FIGS. 2 to 10D, in the present application, the spray tube 202 Longitudinal The falling film evaporator 100 has a housing 101. Longitudinal The spray ports 301 are arranged perpendicular to the housing 101 and have a rectangular shape, so that the refrigerant sprayed from the spray tubes 202 is substantially Longitudinal The refrigerant can flow in a direction perpendicular to the axis of the heat exchange tube 201, thereby increasing the movement space of the refrigerant, so that the refrigerant can be uniformly sprayed on the surface of the perforated plate 205. If the arrangement of the spray tubes 202 in the present application is not adopted, the movement path of the refrigerant after being sprayed from the spray tubes 202 is likely to be restricted due to the insufficient radial width of the housing 101, so that the refrigerant cannot be uniformly sprayed on the heat exchange tube bundle 201.

[0036] FIG. 11 shows a comparative example of the position configuration of the spray tube 1202 inside the falling film evaporator. Longitudinal The hole plate 205 Longitudinal Unlike the embodiment of the present application, in which the spray pipe 1202 is arranged perpendicular to the Longitudinal However, the hole plate 1205 LongitudinalAs shown in FIG. 11, the length of the spray tube 1202 is substantially the same as the length of the cover plate 1302, the perforated plate 1205, and the side stop plate 1204. The spray tube 1202 is disposed on the perforated plate 1205, and the liquid inlet tube 1102 and the liquid inlet box 1203 are both disposed on the spray tube 1202. The refrigerant may enter the liquid inlet box 1203 from the liquid inlet tube 1102, and then be sprayed on the surface of the perforated plate 1205 by the spray tube 1202. The configuration of the spray ports 1301 on the spray tube 1202 in the comparative example is the same as the configuration of the spray ports 301 shown in FIG. 5 in the embodiment of the present application. That is, the multiple spray ports 1301 are parallel to each other, and the spray tube 1202 Longitudinal The difference is that the spray tube 1202 in the comparative example is Longitudinal The hole plate 1205 Longitudinal Therefore, due to the above-mentioned configuration of the spray ports 1301, the refrigerant moves substantially in the width direction of the perforated plate 1205 after being sprayed from the spray tubes 1202.

[0037] Figure 12 shows an axial cross-sectional view of a falling film evaporator at the position of the liquid inlet tube 1102 with the spray tube 1202 configuration shown in Figure 11. As shown in Figure 12, the liquid inlet box 1203, the spray tube 1202, the cover plate 1302, the perforated plate 1205 and the side stop plate 1204 are all located inside the housing 1101 of the falling film evaporator, and the length of the spray tube 1202, the cover plate 1302, the perforated plate 1205 and the side stop plate 1204 is substantially the same as the length of the housing 1101.

[0038] 13 shows a radial cross-sectional view of the falling film evaporator at the position of the liquid inlet tube 1102 having the spray tube 1202 position configuration shown in FIG. 11. As shown in FIG. 13, the left and right sides of the falling film evaporator are symmetrically configured, the spray tube 1202 is arranged at the center position in the width direction of the perforated plate 1205, two heat exchange tube bundles 1201 are provided under the perforated plate 1205, one heat exchange tube bundle 1201 is accommodated in the accommodation space formed by the perforated plate 1205 and the side stop plates 1204 on both sides thereof, the other heat exchange tube bundle 1201 is arranged in the bottom space of the housing 1101, and the heat exchange tubes in the two heat exchange tube bundles 1201 are arranged in the bottom space of the housing 1101. Longitudinal The housing 1101 Longitudinal It is configured as in.

[0039] Figure 14 shows the path of the refrigerant after being sprayed from the spray tube 1202 shown in Figure 13. As shown in Figure 14, the refrigerant sprayed from the spray tube 1202 has a high initial velocity, and when it reaches the edge of the width direction of the perforated plate 1205, the refrigerant still maintains a certain transverse velocity, but the path of the refrigerant is substantially in the radial direction of the housing 1101, and the radial width of the housing 1101 is narrow, limiting the width of the perforated plate 1205, so that the perforated plate 1205 does not have enough width for the refrigerant to proceed further. The refrigerant with a certain transverse velocity develops vortices at the edge of the perforated plate 1205 under the blocking action of the cover plate 1302, and as a result, a larger amount of refrigerant is collected at both ends of the width direction of the perforated plate 1205 than at the center position.

[0040] FIG. 15 shows the flow velocity of the distributed refrigerant flowing through different positions in the width direction of the perforated plate 1205 shown in FIG. 14. The width of the perforated plate 1205 is limited due to the narrow radial width of the housing 1101. Therefore, the width of the spray tubes 1202 is limited. Longitudinal Housing 1101 Longitudinal15, the refrigerant sprayed from the spray tubes 1202 still has a high transverse velocity when it reaches the edge of the width of the perforated plate 1205, so the movement is restricted, resulting in uneven distribution of the refrigerant across the width of the perforated plate 1205. As shown in FIG. 15, various components in the falling film evaporator are arranged symmetrically in the radial direction, so the flow velocity of the refrigerant is also symmetric across the width of the perforated plate 1205 with respect to the center point of the perforated plate 1205. Specifically, the flow velocity of the refrigerant is minimum at the center position directly below the spray tubes 1202, and as the position moves toward both sides of the width of the perforated plate 1205, the flow velocity gradually increases, and the flow velocity is maximum at the positions of the two edges of the perforated plate 1205.

[0041] As can be seen, in the comparative falling film evaporator, the spray tube 1202 Longitudinal Housing 1101 Longitudinal As a result, the refrigerant sprayed from the spray tube 1202 moves substantially in the radial width direction of the housing 1101, and since the radial width of the housing 1101 is narrow, the movement range of the refrigerant after being sprayed from the spray tube 1202 is greatly limited, and as a result, the refrigerant cannot be sprayed uniformly on the heat exchange tube. Longitudinal Housing 101 Longitudinal 202 is configured to be perpendicular to the housing 101 so that the refrigerant sprayed from the spray tube 202 is substantially LongitudinalTherefore, the refrigerant can move along a longer path, which prevents the refrigerant from being sprayed unevenly on the heat exchange tubes due to the restricted movement of the refrigerant, and thus avoids the phenomenon of "dry spots" on the heat exchange tubes caused by the uneven spray of the refrigerant. In addition, the above-mentioned configuration of the present application lengthens the refrigerant's movement path in the width direction of the spray tube 202, that is, when the configuration of the spray tube 202 in the embodiment of the present application is used, the reach area when the unit length of the spray tube 202 sprays on the perforated plate 205 is greatly increased, therefore, to achieve the spray effect for the same area of ​​the perforated plate, the configuration of the spray tube 202 in the embodiment of the present application is used, the length of the spray tube 202 is greatly shortened, and correspondingly, the above-mentioned configuration also reduces the number of openings of the spray ports 301 on the spray tube 202, which greatly reduces the difficulty and cost of manufacturing the spray tube.

[0042] Although the present application has been described with reference to the specific embodiments shown in the drawings, it should be understood that the falling film evaporator of the present application may have many variations without departing from the spirit and scope and context of the teachings of the present application. Those skilled in the art will appreciate that there are various ways to change the structural details of the embodiments disclosed in the present application, all of which are within the spirit and scope of the present specification and claims. [Aspect 1] In the falling film evaporator, the falling film evaporator (100) comprises: A housing (101) having a receiving cavity; a heat exchange tube (304), the length of the heat exchange tube (304) being the same as the length of the housing (101); a perforated plate (205) disposed above the heat exchange tubes (304) and having a plurality of distribution holes (305); a spray tube (202), the spray tube (202) being disposed above the perforated plate (205), the spray tube (202) having a plurality of spray ports (301) spaced apart along the length of the spray tube (202), the spray ports (301) being configured to spray refrigerant toward the perforated plate (205); a liquid inlet tube (102) in fluid communication with the spray tube (202) such that the refrigerant flowing through the liquid inlet tube (102) can flow into the spray tube (202); the heat exchange tubes (304), the perforated plate (205), and the spray tubes (202) are all disposed within the accommodating cavity, and a length direction of the spray tubes (202) is substantially perpendicular to a length direction of the housing (101). [Aspect 2] 2. The falling film evaporator according to claim 1, wherein the length of the perforated plate (205) is the same as the length of the housing (101), and the spray ports (301) are configured to allow the refrigerant to flow in the length direction of the perforated plate (205) after the refrigerant is sprayed toward the perforated plate (205). [Aspect 3] 2. The falling film evaporator according to claim 1, wherein the bottom of the spray tube (202) has an arcuate end surface (501), the arcuate end surface (501) protruding towards the perforated plate (205), the spray ports (301) are strip-shaped, and at least a portion of the spray ports (301) is located on the arcuate end surface (501). Aspect 4 The falling film evaporator according to aspect 1, characterized in that the spray tube (202) has two extensions (801) extending in the longitudinal direction of the housing (101), the ends of the extensions (801) have arcuate end faces (501) protruding outward, the spray ports (301) are strip-shaped, and at least a portion of the spray ports (301) is located on the arcuate end faces (501). Aspect 5 5. The falling film evaporator according to claim 4, wherein the cross section of the spray tube (202) has a flattened elliptical shape, the two extensions (801) are respectively located at the left and right ends of the spray tube (202), the spray port (301) is strip-shaped, and the spray port (301) extends from the bottom of the spray tube (202) towards the arc-shaped end faces (501) at the left and right ends of the spray tube (202), respectively. Aspect 6 The falling film evaporator according to aspect 4, characterized in that the cross section of the spray tube (202) has an inverted "Y" shape, the two extension parts (801) are separately arranged at the bottom of the spray tube (202) and extend diagonally downward, the spray port (301) is strip-shaped, and at least a portion of the spray port (301) is arranged on the arc-shaped end surface (501). Aspect 7 2. The falling film evaporator of claim 1, wherein a plurality of the spray pipes (202) are disposed within the falling film evaporator (100), and upper ends of the plurality of spray pipes (202) are in fluid communication with each other such that the plurality of spray pipes (202) are in fluid communication with each other. Aspect 8 8. The falling film evaporator of claim 7, wherein the number of the spray tubes (202) is an even number, and the plurality of spray tubes (202) are symmetrically distributed with respect to the liquid inlet tube (102). Aspect 9 2. The falling film evaporator according to claim 1, wherein the falling film evaporator (100) further comprises a liquid inlet box (203), the liquid inlet box (203) being disposed between the liquid inlet pipe (102) and the spray pipe (202), such that the liquid inlet pipe (102) and the spray pipe (202) can be fluidly connected to each other via the liquid inlet box (203). Aspect 10 The falling film evaporator (100) according to aspect 1, characterized in that the falling film evaporator (100) further comprises a cover plate (302), the cover plate (302) being arranged at an upper part of the spray tube (202), the two side edges of the cover plate (302) extending towards the perforated plate (205) and directly or indirectly connected to the two side edges of the perforated plate (205) in a sealing manner.

Claims

1. In a falling film evaporator, a housing having a receiving cavity; a heat exchange tube, the longitudinal direction of the heat exchange tube being the same as the longitudinal direction of the housing; a perforated plate disposed above the heat exchange tubes and including a plurality of distribution holes; a spray tube disposed above the perforated plate and including a plurality of spray ports, each having a first extension and a second extension extending longitudinally of the housing, the first extension having an end with a first outwardly projecting arcuate end surface and the second extension having an end with a second outwardly projecting arcuate end surface, the plurality of spray ports being in the form of a plurality of strips, at least a portion of the plurality of strips being disposed on the first outwardly projecting arcuate end surface and the second outwardly projecting arcuate end surface, the plurality of spray ports being distributed at intervals longitudinally of the spray tube, the plurality of spray ports being configured to spray refrigerant toward the perforated plate; a liquid inlet tube in fluid communication with the spray tube, the refrigerant flowing through the liquid inlet tube being able to flow into the spray tube; The heat exchange tubes, the perforated plate, and the spray tubes are all disposed within the accommodating cavity, and the longitudinal direction of the spray tubes is substantially perpendicular to the longitudinal direction of the housing.

2. 2. The falling film evaporator of claim 1, further comprising a longitudinal direction of the perforated plate that is the same as the longitudinal direction of the housing, the longitudinal direction of the perforated plate being configured to allow the refrigerant to flow in the longitudinal direction of the perforated plate after the refrigerant is sprayed from the plurality of spray ports toward the perforated plate.

3. 2. The falling film evaporator of claim 1, wherein the cross section of the spray tube comprises a flattened elliptical shape, and the plurality of strips are disposed on a portion of the spray tube facing the perforated plate, the first outwardly projecting arcuate end surface, and the second outwardly projecting arcuate end surface.

4. 2. The falling film evaporator of claim 1, wherein the cross section of the spray tube comprises an inverted "Y" shape, and the first and second expansion portions extend diagonally from the spray tube toward the perforated plate, separately.

5. 2. The falling film evaporator of claim 1, comprising a plurality of the spray tubes disposed within the falling film evaporator, the inlet ends of the plurality of spray tubes being in communication with one another such that the plurality of spray tubes are in fluid communication with one another.

6. 6. The falling film evaporator of claim 5, wherein the number of the plurality of spray tubes is an even number, and the plurality of spray tubes are symmetrically distributed with respect to the liquid inlet tube.

7. 2. The falling film evaporator of claim 1, further comprising a liquid inlet box, the liquid inlet box being disposed between the liquid inlet pipe and the spray pipe, such that the liquid inlet pipe and the spray pipe can be in fluid communication with each other through the liquid inlet box.

8. 8. The falling film evaporator of claim 7, further comprising a cover plate disposed between the spray tubes and the liquid inlet box, the cover plate having first and second side edges extending toward the perforated plate and connected in a sealing manner to the first and second side edges, respectively, of the perforated plate.

9. 1. A system for distributing refrigerant over heat exchange tubes, comprising: a housing having a receiving cavity; a heat exchange tube, the longitudinal direction of the heat exchange tube being the same as the longitudinal direction of the housing; a perforated plate including a plurality of distribution holes, the longitudinal direction of the perforated plate being the same as the longitudinal direction of the housing; a spray tube including a plurality of spray ports spaced apart along a length of the spray tube, the plurality of spray ports configured to spray refrigerant toward the perforated plate, the perforated plate being disposed between the heat exchange tube and the spray tube; a liquid inlet tube in fluid communication with the spray tube, whereby the refrigerant flowing through the liquid inlet tube can flow into the spray tube; a liquid inlet box in fluid communication with the liquid inlet pipe and the spray pipe, whereby the liquid inlet pipe and the spray pipe are in fluid communication with each other via the liquid inlet box; a cover plate disposed between the spray tube and the liquid inlet box, a first side edge of the cover plate and a second side edge of the cover plate extending toward the perforated plate, the first side edge of the cover plate being sealingly connected to the first side edge of the perforated plate and the second side edge of the cover plate being sealingly connected to the second side edge of the perforated plate; a gas exhaust pipe in fluid communication with the housing and configured to exhaust gaseous refrigerant from the accommodating cavity; The heat exchange tubes, the perforated plate, and the spray tubes are all disposed within the storage cavity, and the longitudinal direction of the spray tubes is substantially perpendicular to the longitudinal direction of the perforated plate, thereby allowing the refrigerant sprayed from the multiple spray ports toward the perforated plate to flow in the longitudinal direction of the perforated plate.

10. 10. The system of claim 9, comprising a plurality of spray tubes including the spray tube disposed above the perforated plate, the number of the plurality of spray tubes being an even number, the plurality of spray tubes being symmetrically distributed with respect to the liquid inlet tube, and the inlet ends of the plurality of spray tubes being in fluid communication with each other through the liquid inlet box.

11. 11. The system of claim 10, further comprising a surface of each of the spray tubes having an arcuate end surface protruding toward the perforated plate, the plurality of spray ports being in the form of a plurality of strips, at least a portion of the plurality of strips being disposed on the arcuate end surface.

12. In a falling film evaporator, a housing having a receiving cavity; a heat exchange tube disposed in the receiving cavity, the heat exchange tube having a longitudinal direction that is the same as a longitudinal direction of the housing; a perforated plate disposed in the receiving cavity and between the heat exchange tube and the spray tube, the perforated plate including a plurality of distribution holes, the longitudinal direction of the perforated plate being the same as the longitudinal direction of the housing; a spray tube disposed within the receiving cavity and including a plurality of spray ports, the spray tube including an arcuate end surface projecting toward the perforated plate, the plurality of spray ports being in the form of a plurality of strips and distributed at intervals along the length of the spray tube, at least a portion of the strips being disposed on the arcuate end surface, the plurality of spray ports being configured to spray refrigerant toward the perforated plate; a liquid inlet tube in fluid communication with the spray tube, whereby the refrigerant flowing through the liquid inlet tube can flow into the spray tube, the longitudinal direction of the spray tube being substantially perpendicular to the longitudinal direction of the perforated plate, whereby the refrigerant sprayed from the plurality of spray ports toward the perforated plate can flow in the longitudinal direction of the perforated plate; the liquid inlet tube bifurcates into a first flow path and a second flow path each extending in the longitudinal direction of the housing and toward the aperture plate; A falling film evaporator, wherein a first spray pipe is disposed at an end of the first flow path of the liquid inlet pipe, and a second spray pipe is disposed at an end of the second flow path of the liquid inlet pipe, and a central axis of the first spray pipe and a central axis of the second spray pipe form an angle of 60° or more.

13. 13. The falling film evaporator of claim 12, wherein the cross section of the spray tube has a flattened elliptical shape with first and second extensions extending away from each other, each of the first and second extensions having an outwardly protruding arcuate end surface, and the plurality of spray ports are in the shape of the plurality of strips, the plurality of strips being disposed on a surface of the spray tube facing the perforated plate and on at least a portion of the arcuate end surface.

14. 13. The falling film evaporator of claim 12, wherein the cross section of the spray tube has an inverted "Y" shape, a first extension portion and a second extension portion are separately disposed on a surface of the spray tube facing the perforated plate and extend obliquely toward the perforated plate, each of the first extension portion and the second extension portion has an outwardly protruding arcuate end surface, the plurality of spray ports are in the shape of a plurality of strips, and the plurality of strips are disposed on the arcuate end surface.

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