Evaporator and adsorption refrigerator

Abstract

This invention discloses an evaporator with an evaporation chamber having a refrigerant vapor outlet. The evaporation chamber is equipped with multiple liquid replenishment trays arranged sequentially from top to bottom. Adjacent liquid replenishment trays form a mass transfer cavity for transferring gaseous refrigerant and connecting to the refrigerant vapor outlet. Each liquid replenishment tray is correspondingly equipped with a horizontally placed heat transfer tube for the flow of cooling medium. The outer side of the heat transfer tube has a capillary structure attached to it for introducing liquid refrigerant from the liquid replenishment tray to the upper part of the heat transfer tube. By setting up multiple layers of liquid replenishment trays and using capillary structures to create a rising film on the upper side of the liquid replenishment trays, the heat transfer tubes can be distributed in layers in the vertical direction, ensuring evaporation efficiency in both vertical and horizontal distribution. This reduces the lateral volume and ensures a sufficient evaporation rate, thus addressing the problem of poor evaporation performance in current evaporators. This invention also discloses an adsorption refrigeration machine including the above-described evaporator.

Description

Technical Field

[0001] This invention relates to the field of heat exchange technology, and more specifically, to an evaporator, and also to an adsorption refrigeration machine including the above-described evaporator. Background Technology

[0002] A flooded evaporator is a type of evaporator where the shell is filled with liquid refrigerant and the heat transfer tubes are immersed in a pool of liquid refrigerant, allowing the liquid refrigerant to boil and evaporate into vapor. However, because the heat transfer tubes must be submerged in liquid refrigerant, flooded evaporators require a considerable amount of refrigerant. Furthermore, the relatively low evaporation pressure within the evaporator makes boiling and evaporation difficult, and the presence of hydrostatic pressure results in lower evaporator efficiency. Falling film or rising film evaporators can ensure good heat transfer performance while reducing refrigerant consumption. However, spray-type falling film evaporators require additional spraying equipment, increasing power consumption and cost, and reducing system reliability. In contrast, rising film evaporators offer greater advantages in reducing refrigerant consumption and ensuring system reliability.

[0003] For example, Chinese patent CN115427743A discloses a hybrid falling film evaporator, which includes a falling film heat transfer zone and an immersed heat transfer zone. The falling film heat transfer zone is equipped with heat transfer tube bundles, with falling film baffles above the tube bundles and baffles on both sides; the bottom of the evaporator has heat transfer tube bundles immersed in liquid, operating in a full-liquid heat transfer mode. This patented solution still has the following problems: Since the refrigerant liquid in the falling film zone heat transfer tube bundles is supplied by falling liquid from the upper falling film baffles, a sufficient amount and uniform distribution of refrigerant are required to ensure that the surface of the heat transfer tube bundles is covered by refrigerant liquid. A stable liquid film is difficult to maintain on the surface of a smooth, horizontal circular tube; therefore, a stable and continuous liquid falling film rate is required to form a stable liquid film. Furthermore, since there is still a full-liquid section at the bottom of the evaporator, a relatively large amount of refrigerant is still needed.

[0004] For example, Chinese patent CN101050926A discloses a liquid rising film evaporator. This device mainly involves embedding or covering a metal wire mesh on the surface of a smooth horizontal circular tube to form a rising thin liquid film, and using the capillary force of the metal wire mesh to draw liquid from a set liquid tank. This patented solution still has the following problems: If the metal wire mesh is not in good contact with the surface of the smooth horizontal circular tube, an air layer may exist, and the liquid film may only be distributed in the metal wire mesh without contacting the tube wall. If dry spots exist on the tube surface, it will lead to a greater thermal resistance. Secondly, embedding or covering the metal wire mesh on the surface of the horizontal circular tube bundle increases the operational difficulty. During long-term operation, the metal wire mesh structure is prone to dirt and scale buildup, and is difficult to clean.

[0005] In the process of realizing this invention, the inventors discovered that the prior art has at least the following problems: the current evaporators are bulky and have poor evaporation effect. Summary of the Invention

[0006] In view of this, the first objective of the present invention is to provide an evaporator that can effectively solve the problem of poor evaporation effect of current evaporators, and the second objective of the present invention is to provide an adsorption refrigeration machine including the above-mentioned evaporator.

[0007] To achieve the first objective mentioned above, the present invention provides the following technical solution: An evaporator is provided with an evaporation chamber having a refrigerant vapor outlet. The evaporation chamber is provided with a plurality of liquid replenishment trays arranged sequentially from top to bottom. A mass transfer cavity for transferring gaseous refrigerant and connecting to the refrigerant vapor outlet is formed between adjacent liquid replenishment trays. Each liquid replenishment tray is correspondingly provided with a horizontally placed heat transfer tube for flowing cooling medium. The outer side of the heat transfer tube has a capillary structure attached to it for introducing liquid refrigerant from the liquid replenishment tray to the upper part of the heat transfer tube.

[0008] During operation, the refrigerant enters the heat transfer tubes. The fluid temperature in the tubes is relatively high, causing it to release heat. Meanwhile, the liquid refrigerant in the external capillary structure evaporates—either through interfacial evaporation or boiling evaporation—and enters the upper space of the heat transfer tubes. Due to the gap design, a mass transfer channel is formed, allowing all the gaseous refrigerant formed during evaporation to pass through the refrigerant vapor outlet, ensuring continuous evaporation. Furthermore, because of the capillary structure, as the water in the upper capillary structure evaporates and a portion of the capillary structure is immersed in the liquid refrigerant in the replenishment tray, capillary force allows it to re-enter the upper part of the heat transfer tubes for continued evaporation. In this evaporator, multiple replenishment trays are installed, and a rising film is created above the replenishment trays via a capillary structure. This allows the heat transfer tubes to be distributed in layers vertically, ensuring efficient evaporation while minimizing lateral volume and maximizing evaporation volume. In summary, this evaporator can effectively solve the problem of poor evaporation performance of current evaporators, while making the evaporator structure more compact.

[0009] In some technical solutions, at least one of the replenishment trays has an overflow port, and liquid refrigerant overflowing from the overflow port can fall into the replenishment tray below.

[0010] In some technical solutions, the overflow ports of two adjacent replenishment trays are horizontally staggered.

[0011] In some technical solutions, a refrigerant return port located at the top of the evaporation chamber and a return pipe located inside the evaporation chamber are also included. One end of the return pipe is connected to the refrigerant return port, and the other end extends to the bottom of the evaporation chamber to pass through each of the replenishment trays. A replenishment port is provided at the connection with each of the replenishment trays to introduce the condensed liquid refrigerant into each of the replenishment trays.

[0012] In some technical solutions, the liquid replenishment tray is provided with a plurality of heat transfer tubes arranged horizontally side by side, and the horizontal direction is perpendicular to the extension direction and the vertical direction of the heat transfer tubes.

[0013] In some technical solutions, the capillary structure is a fin groove structure disposed on the outer wall of the heat transfer tube.

[0014] In some technical solutions, a refrigerant return port located at the top of the evaporation chamber is also included. A flow guide baffle is provided between the refrigerant return port and the heat transfer tube to guide the liquid refrigerant to flow laterally and be introduced into each of the replenishment trays.

[0015] In some technical solutions, along the extension direction of the heat transfer tube, there are mixing chambers at both ends of the evaporation chamber, and the two ends of the plurality of heat transfer tubes are respectively connected to the mixing chambers at both ends.

[0016] In some technical solutions, the system includes a main body shell and tube sheets disposed at both ends of the main body shell. One side of the tube sheet faces the mixing chamber and the other side faces the evaporation chamber. The two ends of the heat transfer tube pass through the tube sheets at both ends to communicate with the mixing chamber on the corresponding side.

[0017] In some technical solutions, a diversion device is provided at one end of the main body shell. The diversion device and the tube sheet enclose a first cavity. The first cavity is divided into at least two mixing cavities by a diversion baffle, which are respectively a cooling medium diversion cavity and a cooling medium confluence cavity.

[0018] In some technical solutions, a flow diversion device is provided at the other end of the main body shell, and the flow diversion device and the tube sheet enclose a second cavity; the first cavity is divided into three mixing chambers arranged sequentially from top to bottom by two horizontally arranged diversion baffles, namely, the cooling medium diversion chamber, the first flow diversion chamber, and the cooling medium confluence chamber; the second cavity is divided into two mixing chambers arranged sequentially from top to bottom by flow diversion baffles, namely, the second flow diversion chamber and the third flow diversion chamber; [The last sentence appears to be incomplete and possibly refers to a separate section about heat transfer tubes.] Tube groups: From top to bottom, a first tube group, a second tube group, a third tube group, and a fourth tube group are formed sequentially; each heat transfer tube in the first tube group is connected at both ends to the cooling medium distribution chamber and the second transfer chamber, each heat transfer tube in the second tube group is connected at both ends to the first transfer chamber and the second transfer chamber, each heat transfer tube in the third tube group is connected at both ends to the first transfer chamber and the third transfer chamber, and each heat transfer tube in the fourth tube group is connected at both ends to the cooling medium confluence chamber and the third transfer chamber.

[0019] In some technical solutions, the main body shell and the diversion device are connected by a flange and clamp the tube sheet between them; the main body shell and the diversion device are connected by a flange and clamp the tube sheet between them; the diversion baffle is inserted into the tube sheet on the corresponding side for a sealed connection; the diversion baffle is inserted into the tube sheet on the corresponding side for a sealed connection.

[0020] In some technical solutions, a refrigerant return port is provided at the top center of the evaporation chamber along the extension direction of the heat transfer tube, and refrigerant vapor outlets are provided at the top of both sides of the refrigerant return port.

[0021] In some technical solutions, at least one heat transfer tube corresponding to the replenishment tray has an interval of 5 mm to 7 mm between adjacent heat transfer tubes; the distance between the heat transfer tube and the lower side of the adjacent upper replenishment tray is between 9 mm and 12 mm; the distance between the heat transfer tube and the bottom surface of the corresponding replenishment tray is between 1 mm and 2 mm; the overflow port height of the replenishment tray is between 2 mm and 5 mm; the width of the fin groove structure is between 0.1 mm and 1 mm; and the immersion rate of the heat transfer tube in the replenishment tray is between 0% and 18%.

[0022] To achieve the second objective mentioned above, the present invention also provides an adsorption refrigeration machine, which includes any of the aforementioned evaporators, comprising an adsorption bed and a condenser. The refrigerant vapor outlet of the evaporator's evaporation chamber is connected to the adsorption chamber of the adsorption bed, and the refrigerant return port of the evaporator's evaporation chamber is connected to the liquid outlet of the condenser. Since the aforementioned evaporator possesses the above-mentioned technical effects, the adsorption refrigeration machine with this evaporator should also possess corresponding technical effects. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the longitudinal cross-sectional structure of the evaporator provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of an evaporator provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the tube sheet surface structure provided in an embodiment of the present invention; Figure 4 A schematic diagram illustrating the flow of gaseous refrigerant formed by evaporation in an evaporator according to an embodiment of the present invention; Figure 5 A schematic diagram of the transverse side structure of the end of the heat transfer tube provided in an embodiment of the present invention; Figure 6 A three-dimensional structural diagram of the end of the heat transfer tube provided in an embodiment of the present invention; Figure 7 A schematic diagram of the liquid replenishment structure of the heat transfer tube provided in an embodiment of the present invention; Figure 8 A schematic diagram of the transverse cross-sectional structure of a second type of evaporator provided in an embodiment of the present invention (heat transfer tubes not shown). Figure 9 This is a three-dimensional structural diagram of the second type of evaporator replenishment tray provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of the cross-sectional structure of a second type of evaporator replenishment tray provided in an embodiment of the present invention.

[0025] The following labels are shown in the attached diagram: 1-Main body shell, 2-Diverter, 3-Converter, 4-Tube sheet, 5-Heat transfer tube, 6-Refill tray, 7-Baffle, 8-Liquid refrigerant, 9-Return pipe; 11-Refrigerant return port, 12-Refrigerant vapor outlet; 21-Cooling medium inlet, 22-Cooling medium outlet, 23-Diverter baffle; 31-Converter baffle; 41-Mounting hole; 51-Fin groove structure; 61-Overflow port, 91-Refill port. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Please see Figures 1-10 , Figure 1 This is a schematic diagram of the longitudinal cross-sectional structure of the evaporator provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of an evaporator provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the tube sheet surface structure provided in an embodiment of the present invention; Figure 4 A schematic diagram illustrating the flow of gaseous refrigerant formed by evaporation in an evaporator according to an embodiment of the present invention; Figure 5 A schematic diagram of the transverse side structure of the end of the heat transfer tube provided in an embodiment of the present invention; Figure 6 A three-dimensional structural diagram of the end of the heat transfer tube provided in an embodiment of the present invention; Figure 7 A schematic diagram of the liquid replenishment structure of the heat transfer tube provided in an embodiment of the present invention; Figure 8 A schematic diagram of the transverse cross-sectional structure of a second type of evaporator provided in an embodiment of the present invention (heat transfer tubes not shown). Figure 9 This is a three-dimensional structural diagram of the second type of evaporator replenishment tray provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of the cross-sectional structure of a second type of evaporator replenishment tray provided in an embodiment of the present invention.

[0028] Falling film or rising film evaporators can ensure good heat transfer performance while reducing refrigerant consumption. However, spray-type falling film evaporators require additional spraying equipment, increasing power consumption and cost, and reducing system reliability. In contrast, rising film evaporators have a greater advantage in reducing refrigerant consumption and ensuring system reliability.

[0029] An evaporator is a heat exchanger that absorbs heat from the liquid flowing through it while allowing the refrigerant to evaporate from the liquid into vapor, directly producing a heating or cooling effect. In adsorption refrigeration systems, the evaporator, as a heat exchange component in the adsorption chiller, affects the overall heat transfer performance of the system; traditional smooth tube bundle flooded evaporators have a heat transfer coefficient of approximately 0.4~1.8 kW / m³. 2 The high refrigerant charge (·K) in adsorption refrigeration systems leads to problems such as larger evaporator size, higher refrigerant charge requirements, and relatively lower heat exchange efficiency. Spray-type falling film evaporators require additional spraying devices and circulating pumps, increasing power consumption and system instability. Falling film evaporators, on the other hand, demand stable and uniform refrigerant distribution and a high falling film rate, making them prone to uneven distribution. Therefore, improving evaporator heat exchange efficiency, structural compactness, and reducing refrigerant charge are key technologies in evaporator design for adsorption refrigeration systems.

[0030] To address the aforementioned problems, this invention provides an evaporator to solve the issues of bulky evaporators and poor evaporation performance.

[0031] Specifically, the evaporator is equipped with an evaporation chamber, which has a refrigerant vapor outlet 12, so that the gaseous refrigerant formed by evaporation can be discharged from the refrigerant vapor outlet 12, such as to the outside or to the adsorption chamber of the adsorption bed. In order to facilitate timely liquid replenishment, a refrigerant return port 11 is generally provided, such as to introduce liquid refrigerant 8 from the condenser's condensation chamber in a timely manner.

[0032] In an adsorption refrigeration system, the gaseous refrigerant formed in the evaporator typically enters the adsorption bed and is adsorbed by the adsorbent. The heat released during this process is carried away by an external fluid. After the adsorbent becomes saturated, a higher-temperature hot fluid is introduced to heat the adsorbent, causing it to desorb the gaseous refrigerant. This desorbent then enters the condenser, where it is cooled and reformed into liquid refrigerant. This liquid refrigerant can then be returned to the evaporator, and the cycle can be repeated continuously.

[0033] The evaporation chamber is equipped with multiple replenishment trays 6 arranged sequentially from top to bottom. Adjacent replenishment trays 6 form mass transfer cavities for transferring gaseous refrigerant, and these cavities are connected to the refrigerant vapor outlet. Mass transfer is typically achieved through a gap between the replenishment tray 6 and the evaporation chamber wall. Each replenishment tray 6 is equipped with a horizontally placed heat transfer tube 5 for the flow of cooling medium. The outer side of the heat transfer tube 5 has capillary structures attached to guide the liquid refrigerant 8 from the replenishment tray 6 to the upper part of the heat transfer tube 5. The cooling medium can also be referred to as a refrigeration fluid.

[0034] During operation, the refrigerant enters the heat transfer tube 5. The fluid temperature in the heat transfer tube 5 is relatively high, causing it to release heat. Meanwhile, the liquid refrigerant 8 in the external capillary structure evaporates, either through interfacial evaporation or boiling evaporation, entering the upper space of the heat transfer tube 5. Due to the gap arrangement, a mass transfer channel is formed, allowing the gaseous refrigerant formed by evaporation to pass through the refrigerant vapor outlet 12, ensuring continuous evaporation. Furthermore, because it is a capillary structure, as the water in the upper capillary structure evaporates and decreases, a portion of the capillary structure is immersed in the liquid refrigerant 8 in the replenishment tray 6. Therefore, the refrigerant is drawn back into the upper part of the heat transfer tube 5 by capillary force, continuing evaporation. In the evaporator described above, multiple layers of replenishment trays 6 are provided, and a rising film is formed on the upper side of the replenishment trays 6 through a capillary structure. This allows the heat transfer tubes 5 to be distributed in layers in the vertical direction, ensuring efficient evaporation in both vertical and horizontal directions, reducing the lateral volume, and guaranteeing the evaporation rate. In summary, this evaporator can effectively solve the problem of poor evaporation performance of current evaporators, while making the evaporator structure more compact.

[0035] Generally speaking, capillary-assisted thin-film evaporation does not involve boiling, and the phase change only occurs at the liquid-gas interface. Compared with constant water level immersion boiling in a smooth circular tube, the heat transfer coefficient of thin-film evaporation can be increased by about 2 times, thus improving the efficiency of the evaporator.

[0036] In some embodiments, liquid is replenished to the capillary structure via the replenishment tray 6, and then to the upper part of the heat transfer tube 5. The effective evaporation area is maximized when the outer wall of the heat transfer tube 5 is just completely covered by the liquid film. Therefore, the immersion depth of the capillary structure significantly affects the replenishment rate and the effective evaporation area. If the immersion depth is too shallow, the replenishment rate decreases, and the proportion of ineffective (dry) evaporation area on the outer wall of the heat transfer tube 5 away from the liquid surface is large, resulting in low evaporation efficiency. Conversely, if the immersion depth is too deep, the replenishment rate is rapid, and the proportion of the submerged boiling area of ​​the heat transfer tube 5 is greater than the liquid film evaporation area, failing to leverage the advantages of rising film evaporation. Therefore, it is preferable that at least one of the replenishment trays 6 has an overflow port 61, and the liquid refrigerant 8 overflowing from the overflow port 61 can fall into the lower replenishment tray 6. This allows for precise control of the liquid level in the replenishment tray 6 through the overflow port 61, ensuring the liquid level remains stable without being too high or too low.

[0037] In some embodiments, to prevent liquid refrigerant 8 from overflowing from the overflow port 61 and gradually flowing downwards through the lower overflow port 61, making it impossible to replenish the adjacent next-layer replenishment tray 6, would result in greater difficulty in replenishing the refrigerant. Therefore, as shown in the attached... Figure 1 As shown, the overflow ports 61 of two adjacent replenishment trays 6 are preferably staggered laterally. Alternatively, the overflow ports 61 of adjacent layers can be aligned to achieve a uniform staggered arrangement.

[0038] In some embodiments, to facilitate direct replenishment of each replenishment tray 6, a return pipe 9 may be included. One end of the return pipe 9 is connected to the refrigerant return port 11 at the top of the evaporator chamber, and the other end extends downwards to penetrate each layer of replenishment trays 6 until the bottom replenishment tray 6. Multiple replenishment ports 91 are evenly distributed at the connection points of each layer of replenishment trays 6. Figure 10 As shown, liquid refrigerant 8, introduced through the refrigerant return port 11, is directly introduced into each of the replenishment trays 6. When the return pipe 9 is vertically arranged, a guide plate extending into the return pipe 9 can be provided at the replenishment port 91. The guide plate is used to guide a portion of the liquid in the return pipe 9 to the replenishment port 91.

[0039] If used in conjunction with the overflow port 61, the return pipe 9 can be connected only to the refrigerant return port 11 and the top liquid replenishment tray 6, while the other liquid replenishment trays 6 are replenished with liquid refrigerant 8 through the upper overflow port 61.

[0040] In some embodiments, to make the overall dimensions more uniform in the horizontal and vertical directions, multiple horizontally arranged heat transfer tubes 5 can be correspondingly provided on the liquid replenishment tray 6. The horizontal direction refers to a direction perpendicular to both the extension direction and the vertical direction of the heat transfer tubes 5. (See attached diagram) Figure 2 As shown, the left and right directions are horizontal, and eighteen heat transfer tubes 5 are installed.

[0041] And generally, an overflow port 61 is provided in the middle of the horizontal direction, as shown in the attached document. Figure 2 In the same replenishment tray 6, nine heat transfer tubes 5 are respectively arranged on the left and right sides of the overflow port 61. Along the extension direction of the heat transfer tubes 5, in two adjacent trays, one is provided with three overflow ports 61 arranged in parallel, and the other is provided with four overflow ports 61 arranged in parallel.

[0042] To better secure each replenishment tray 6, the replenishment tray 6 can be provided with slots on the corresponding side walls to cooperate with each heat transfer tube 5.

[0043] In some embodiments, the capillary structure can be a fin groove structure 51 disposed on the outer wall of the heat transfer tube. Of course, the capillary structure can also be a sponge structure. For easy drainage, the capillary structure is generally arranged around the heat transfer tube body, or it can be in an inverted U-shape to sit on the heat transfer tube 5. In use, the liquid level in the replenishment tray 6 should be ensured to be higher than the lower part of the capillary structure and lower than the upper part of the capillary structure.

[0044] Fin groove structure 51 refers to the groove structure formed by fins, as shown in the attached figure. Figure 5 , 6As shown, the heat transfer tube 5 includes a cylindrical tube body and multiple annular fins arranged sequentially and side-by-side along the axial direction, surrounding the cylindrical tube body. The annular fins are spaced apart by very small gaps, such as between 0.1 mm and 1 mm, to form a fin groove structure 51. When the lower part contacts the liquid adsorbent, part of the gap between adjacent annular fins is immersed in the liquid adsorbent, while the other part is not immersed but generates capillary force, allowing the lower liquid adsorbent to be drawn into the upper position. This structure not only facilitates membrane placement but also improves heat transfer efficiency.

[0045] In some embodiments, the refrigerant return port 11 can be located at the top or the side to allow liquid refrigerant 8 to enter at least the top-layer replenishment tray 6. To avoid interference and for convenience, a refrigerant return port 11 located at the top of the evaporation chamber is preferably also included. A baffle 7 can be provided between the refrigerant return port 11 and the heat transfer tube 5 to guide the liquid refrigerant to flow laterally into the top-layer replenishment tray 6, which can greatly reduce the impact on the top-layer heat transfer tube 5.

[0046] In some embodiments, when multiple heat transfer tubes 5 are arranged, they can be connected end-to-end, such as as a single coil. However, this results in a large flow path, high flow resistance, and poor heat transfer performance. Therefore, mixing chambers can be provided at both ends of the evaporation chamber along the extension direction of the heat transfer tubes 5. The ends of the multiple heat transfer tubes 5 are connected to these mixing chambers, allowing direct flow through the mixing chambers to significantly reduce the flow path. This also makes installation more convenient, especially for arranging the tray, which can be placed first, followed by the heat transfer tubes 5.

[0047] In some embodiments, each end may have only one mixing chamber, which serves as a cooling medium distribution chamber and a cooling medium confluence chamber, respectively. In this case, the flow path is only the length of the heat transfer tube 5, which is convenient for installation, but the flow path is too short.

[0048] In some embodiments, after the mixing chamber is provided, for ease of communication, a main shell 1 and tube sheets 4 disposed at both ends of the main shell 1 can be specifically provided. In this case, the main shell 1 and the tube sheets 4 at both ends together form an evaporation chamber. One side of the tube sheet 4 faces the mixing chamber and the other side faces the evaporation chamber. The two ends of the heat transfer tube 5 pass through the tube sheets 4 at both ends to communicate with the mixing chamber on the corresponding side.

[0049] In some embodiments, a flow-diverting device 2 and a flow-converting device 3 can be respectively provided at both ends of the main body shell 1. Correspondingly, the flow-diverting device 2 and the tube sheet 4 can enclose a first cavity, and the first cavity is divided into at least two mixing chambers by a flow-diverting baffle 23, namely a cooling medium flow-diverting chamber and a cooling medium confluence chamber. At this time, a cooling medium inlet 21 is provided on the side of the cooling medium flow-diverting chamber away from the evaporation chamber, and a cooling medium outlet 22 is provided on the side of the cooling medium confluence chamber away from the evaporation chamber. At this time, the temperature of the cooling medium outlet 22 will be lower than the temperature of the cooling medium inlet 21. The cooling medium flow-diverting chamber and the cooling medium confluence chamber are provided on the same side, which greatly facilitates the external output and input of the cooling medium.

[0050] At this time, the flow transfer device 3 can form a mixing chamber with the tube sheet 4 on the corresponding side, and the flow path of the cooling medium is U-shaped.

[0051] In some embodiments, the flow diversion device 3 and the tube sheet 4 can enclose a second cavity; wherein the first cavity is divided into three mixing chambers arranged sequentially from top to bottom by two vertically arranged flow diversion baffles 23, namely, the cooling medium diversion chamber, the first flow diversion chamber, and the cooling medium confluence chamber. The second cavity is divided into two mixing chambers arranged sequentially from top to bottom by a flow diversion baffle 31, namely, the second flow diversion chamber and the third flow diversion chamber. This increased flow diversion allows for a longer flow path for the cooling medium.

[0052] The tube groups containing each of the heat transfer tubes 5 are arranged from top to bottom as follows: first tube group, second tube group, third tube group, and fourth tube group. That is, all the heat transfer tubes 5 are divided into four groups, as shown in the attached diagram. Figure 2 As shown, there are eight rows of tubes arranged from top to bottom, but they are divided into four groups. Each group consists of two adjacent rows of tubes, one above the other. The bottommost tube group does not need to be equipped with a replenishment tray 6; the cavity formed at the bottom of the evaporation chamber can be used as the replenishment cavity. Therefore, the eight rows of tubes can be equipped with only seven replenishment trays 6.

[0053] Each heat transfer tube 5 in the first tube group is connected to the cooling medium distribution cavity and the second circulation cavity at both ends, respectively; each heat transfer tube 5 in the second tube group is connected to the first circulation cavity and the second circulation cavity at both ends, respectively; each heat transfer tube 5 in the third tube group is connected to the first circulation cavity and the third circulation cavity at both ends, respectively; and each heat transfer tube 5 in the fourth tube group is connected to the cooling medium confluence cavity and the third circulation cavity at both ends, respectively.

[0054] In use, the cooling medium passes sequentially through the cooling medium inlet 21, the cooling medium distribution chamber, the first pipe group, the second transfer chamber, the second pipe group, the first transfer chamber, the third pipe group, the third transfer chamber, the fourth pipe group, and the cooling medium confluence chamber, and then flows out from the cooling medium outlet 22.

[0055] In some embodiments, for ease of installation, it is preferable that the main housing 1 and the diversion device 2 are connected by a flange and clamped together by the tube sheet 4, and the main housing 1 and the diversion device 3 are connected by a flange and clamped together by the tube sheet 4. The diversion baffle 23 is inserted into the tube sheet 4 on the corresponding side for a sealed connection, and the diversion baffle 31 is inserted into the tube sheet 4 on the corresponding side for a sealed connection.

[0056] In some embodiments, a refrigerant return port 11 may be provided at the top center of the main body shell 1 along the extension direction of the heat transfer pipe 5, and refrigerant vapor outlets 12 may be provided at the top centers on both sides of the refrigerant return port 11. This is to prevent the liquid refrigerant 8 flowing back from the refrigerant return port 11 in the middle from interfering with the flow of gaseous refrigerant. After the gaseous refrigerant is generated, it will disperse from the center to the surrounding areas and then flow upward from the edges. Therefore, a gap is formed between at least one side of the replenishment tray 6 and the wall of the evaporation chamber to facilitate the flow of gaseous refrigerant.

[0057] In some embodiments, the heat transfer tubes 5 corresponding to at least one of the replenishment trays 6 may be spaced 5 mm to 7 mm apart; the distance between the heat transfer tube 5 and the lower side of the adjacent upper replenishment tray 6 may be 9 mm to 12 mm; the distance between the heat transfer tube 5 and the bottom surface of the corresponding replenishment tray 6 may be 1 mm to 2 mm; the height of the overflow port 61 of the replenishment tray 6 may be 2 mm to 5 mm; the width of the fin groove structure 51 may be 0.1 mm to 1 mm; and the immersion rate of the heat transfer tube 5 in the replenishment tray 6 may be 0% to 18%. These parameters are not strictly required and may exceed the above ranges. The values ​​mentioned above should include both values.

[0058] In some implementations, rising film evaporators are provided, which can be applied to adsorption refrigeration machines. This technique, utilizing capillary-assisted rising film evaporation, overcomes the problems of enhanced heat transfer and reduced refrigerant charge, resulting in a compact evaporator with highly efficient evaporation characteristics. For details, please refer to... Figures 1 to 6 The evaporator mainly includes the main shell 1, the distribution device 2, the transfer device 3, the tube sheet 4, the heat transfer tube 5, the liquid replenishment tray 6, the baffle 7, and the liquid refrigerant 8.

[0059] As attached Figure 2 As shown, the cross-section of the main outer shell 1 is square. (See attached image.) Figure 1 As shown, the inner cavity of the main body shell 1 forms an evaporation chamber, and a refrigerant return port 11 connected to the evaporation chamber is provided for replenishing liquid refrigerant into the evaporation chamber. Specifically, in the adsorption refrigeration machine, the refrigerant return port 11 is connected to the liquid outlet of the condenser so that liquid refrigerant can be replenished from the condenser. In this case, the refrigerant can also be called the adsorption working fluid.

[0060] The main casing 1 is also provided with a refrigerant vapor outlet 12 that communicates with the evaporation chamber, so that the gaseous refrigerant evaporated in the evaporation chamber can be discharged from the refrigerant vapor outlet 12. Specifically, in the adsorption refrigeration machine, the refrigerant vapor outlet 12 is connected to the adsorption chamber of the adsorption bed for adsorption vapor, so that it can be adsorbed by the adsorbent in the adsorption chamber.

[0061] The refrigerant return port 11 and the refrigerant vapor outlet 12 can both be located on the top of the main body shell 1, or they can be located on the upper side. Along the extension direction of the heat transfer pipe 5, the refrigerant return port 11 is located in the middle of the main body shell 1, and in this direction, a refrigerant vapor outlet 12 is located on each side of the refrigerant return port 11 to prevent the evaporated gaseous refrigerant from passing laterally through the portion directly below the refrigerant return port 11.

[0062] The flow distribution device 2 is used to distribute external cooling fluid to multiple corresponding heat transfer tubes 5, and simultaneously collect the cooling fluid flowing out of the multiple heat transfer tubes 5 for unified outflow to the outside. The flow distribution device 2 is provided with a cooling medium inlet 21 and a cooling medium outlet 22, and an internal flow-dividing baffle 23 to at least separate a cooling medium distribution chamber connected to the cooling medium inlet 21 and a cooling medium collection chamber connected to the cooling medium outlet 22. (See attached diagram) Figure 1 As shown, two flow dividers 23 are provided to divide the cavity of the flow divider 2 into a cooling medium flow divider cavity, a first flow transfer cavity and a cooling medium confluence cavity from top to bottom.

[0063] The flow transfer device 3 is mainly used for flow transfer, that is, to form a flow transfer chamber, so as to introduce the cooling medium flowing out of a part of the heat transfer tubes 5 into another part of the heat transfer tubes 5, thereby realizing flow transfer. If only the cooling medium distribution chamber and the cooling medium collection chamber are separated, then only one flow transfer chamber needs to be provided.

[0064] As attached Figure 1 As shown, a flow-diverting baffle 31 is installed inside the flow-diverting device 3 to divide the inner cavity of the flow-diverting device 3 into a second flow-diverting cavity and a third flow-diverting cavity from top to bottom. At this time, the cooling medium enters the cooling medium distribution cavity from the cooling medium inlet 21, and then flows from the cooling medium distribution cavity into the first heat transfer tube, and then flows from the first heat transfer tube into the second flow-diverting cavity; then flows from the second flow-diverting cavity into the second heat transfer tube, and then flows from the second heat transfer tube into the first flow-diverting cavity; then flows from the first flow-diverting cavity into the third heat transfer tube, and then flows from the third heat transfer tube into the third flow-diverting cavity; then flows from the third flow-diverting cavity into the fourth heat transfer tube, and then flows from the fourth heat transfer tube into the cooling medium collection cavity, and then flows from the cooling medium collection cavity into the cooling medium outlet 22 for discharge.

[0065] Of course, as mentioned above, when more flow conversions are needed, more diversion baffles 23 and more flow conversion baffles 31 can be set to form more flow conversion cavities.

[0066] The flow distribution device 2 and the flow transfer device 3 are located at opposite ends of the main body shell 1. The shell portions of the flow distribution device 2, the flow transfer device 3, and the main body shell 1 are assembled and connected to form the evaporator frame. Along the extension direction of the heat transfer tube 5, the cross-sectional profiles of the shell portions of the flow distribution device 2, the flow transfer device 3, and the main body shell 1 are equal and aligned. Specifically, they can be projected onto a plane perpendicular to the extension direction of the heat transfer tube 5. As shown in the attached figures, they are all square, with all four sides aligned.

[0067] As attached Figure 1 As shown, the outer wall of the diverting device 2 and the main housing 1 both have raised edges at their contact points, so that the raised edges of the diverting device 2 and the main housing 1 can be connected by bolts. Correspondingly, the outer wall of the diverting device 3 and the main housing 1 both have raised edges at their contact points, so that the raised edges of the diverting device 3 and the main housing 1 can be connected by bolts. These raised edges can also be referred to as flange structures.

[0068] The main outer shell 1 has tube sheets 4 at both ends to seal the central evaporation chamber. The two ends of the heat transfer tubes 5 pass through the tube sheets 4 at either end or through holes on the connecting tube sheets 4. The two ends of the heat transfer tubes 5 extend into corresponding chambers to communicate with them. For example, the two ends of the first part of the heat transfer tubes extend into the cooling medium distribution chamber and the second transfer chamber, respectively. Figure 3 As shown, the tube sheet 4 also supports the heat transfer tubes 5. The mounting holes 41 of the tube sheet 4 and the heat transfer tubes 5 need to be in sealed contact to ensure the evaporation chamber is sealed and to isolate the cooling medium and refrigerant. The end of the heat transfer tube 5 is inserted into the mounting hole 41 to mate with it.

[0069] Multiple heat transfer tubes 5 are arranged in multiple rows within the main body shell 1, with each row containing multiple heat transfer tubes 5. There should be a certain gap between adjacent heat transfer tubes in a single row, such as a gap width of approximately 5mm-7mm (millimeters), which can be larger than the aforementioned range. Furthermore, to ensure mass transfer and structural compactness, the spacing between adjacent rows of heat transfer tubes 5 can be approximately 9mm-12mm. The heat transfer tubes 5 penetrate the tube sheets 4 on both sides to connect the flow distribution device 2 and the flow transfer device 3.

[0070] A baffle 7 is installed inside the main shell 1 between the refrigerant return port 11 and the heat transfer tube assembly 5 to prevent the refrigerant liquid falling from the refrigerant return port 11 from directly splashing onto the uppermost heat transfer tube 5. A replenishment tray 6 is provided on the lower side of each row of heat transfer tube assemblies 5, with the lower side of the heat transfer tube higher than the upper surface of the corresponding replenishment tray 6, preferably 1mm-2mm higher. An overflow port 61, 2mm-5mm high, can be provided in the replenishment tray 6 to maintain a stable refrigerant level. The overflow ports 61 on adjacent replenishment trays 6 are staggered to avoid mutual interference. The overflow port 61 determines the liquid level height of the replenishment tray 6. The overflow port 61 should be higher than the lower side of the corresponding row of heat transfer tubes 5, but lower than the upper side of the corresponding row of heat transfer tubes 5, so that the lower side of the heat transfer tubes 5 is immersed in liquid refrigerant. However, the immersion height is preferably between one-tenth and one-quarter of the total height of the heat transfer tubes 5, preferably one-sixth. For a circular tube, the total height of heat transfer tube 5 is equal to the outer diameter of the heat transfer tube.

[0071] As attached Figure 5 , 6 As shown, the surface of the heat transfer tube 5 has a fin groove structure 51 to form capillary force, so that the liquid refrigerant in the liquid replenishment tray 6 can move upward under the action of capillary force to enter the fin groove structure 51 at the top of the heat transfer tube 5, and exchange heat with the cooling medium in the heat transfer tube 5 to absorb heat, and then evaporate to form gaseous refrigerant.

[0072] like Figure 2 As shown, liquid refrigerant enters the evaporator through the refrigerant return port 11, flows through the refrigerant baffle 7 to the uppermost liquid replenishment tray 6, and when the liquid level in the uppermost liquid replenishment tray 6 is higher than the overflow port 61, the liquid refrigerant flows to the next layer, and so on, the liquid refrigerant overflows into each layer of liquid replenishment tray 6 in sequence.

[0073] like Figure 4 This indicates the mass transfer path of the refrigerant as it evaporates from a liquid to a vapor. In practical applications, due to the lower pressure in the evaporator, the evaporation temperature of the refrigerant is lower than the temperature of the cooling medium flowing in from the cooling medium inlet 21.

[0074] like Figure 7 As shown, the refrigerant liquid condensed by the condenser enters the evaporator through the refrigerant return port 11 and is distributed in the replenishment tray 6. The heat transfer tubes 5 are partially immersed in the liquid refrigerant 8, with an immersion rate of approximately 0% to 18%. The liquid refrigerant 8 rises under the capillary force of the finned groove structure 51, spreading to form a liquid film on the surface of the heat transfer tube assembly 5. Therefore, when the cooling medium enters the heat transfer tube assembly 5 through the cooling medium inlet 21, the heat of the cooling medium is sequentially transferred to the metal tube wall and finned groove structure 51 of the heat transfer tube assembly 5, and the temperature of the cooling medium gradually decreases. After absorbing heat, the liquid refrigerant 8 rises to its evaporation temperature, and evaporates into refrigerant vapor on the surface of the heat transfer tube assembly 5. The refrigerant vapor (dashed arrow) is as follows: Figure 4 As shown, the refrigerant flows upward along the mass transfer channel and leaves the evaporator from the refrigerant vapor outlet 12. As the refrigerant continuously absorbs heat and evaporates, the temperature of the cooling medium continuously decreases. That is, the temperature of the cooling medium leaving the evaporator from the cooling medium outlet 22 is lower than its temperature when it flows into the evaporator from the cooling medium inlet 21, thereby achieving a cooling effect.

[0075] In some embodiments, as shown in the appendix Figure 8 As shown, there is no need to install baffle 7. Instead, a return pipe 9 is installed to connect the refrigerant return port 11 to each layer of replenishment tray 6 to replenish the refrigerant to each layer of replenishment tray 6. The heat transfer tube group 5 is distributed in the arc-shaped channel of the replenishment tray 6.

[0076] like Figure 8 , 9 As shown in Figure 10, liquid inlets 91 are distributed on the pipe wall at the connection between the refrigerant return pipe 9 and each layer of liquid replenishment tray 6. The liquid refrigerant 8 condensed in the condenser flows into the refrigerant return pipe 9 through the refrigerant return inlet 11 and is distributed to each layer of liquid replenishment tray 6 through the liquid replenishment inlet 91. When the liquid level in the liquid replenishment tray 6 submerges the liquid replenishment inlet 91, the liquid level of the liquid refrigerant 8 in the liquid replenishment tray 6 no longer rises.

[0077] After the liquid refrigerant 8 evaporates and forms a liquid film on the surface of the heat transfer tube 5, the liquid level in the replenishment tray 6 decreases. When the liquid level is lower than the height of the replenishment port 91, the liquid refrigerant 8 in the refrigerant return pipe 9 flows into the replenishment tray 6 in a timely manner through the replenishment port 91, thereby ensuring a stable liquid level in the replenishment tray.

[0078] In this implementation case, the liquid refrigerant 8 is gradually replenished from the liquid inlet 91 into the liquid inlet tray 6 and distributed to the area below the heat transfer tube 5. This effectively avoids the impact of refrigerant backflow and dripping on the evaporation and mass transfer of the liquid film on the surface of the heat transfer tube 5. This implementation case has the characteristics of self-driven, uninterrupted, and gradual liquid replenishment technology.

[0079] Based on the evaporator provided in the above embodiments, the present invention also provides an adsorption refrigeration machine. This adsorption refrigeration machine includes any one of the evaporators described in the above embodiments, comprising an adsorption bed and a condenser. The refrigerant vapor outlet 12 of the evaporator's evaporation chamber is connected to the adsorption chamber of the adsorption bed, and the refrigerant return port 11 of the evaporator's evaporation chamber is connected to the liquid outlet of the condenser. Since this adsorption refrigeration machine uses the evaporator described in the above embodiments, the beneficial effects of this adsorption refrigeration machine are explained in the above embodiments.

[0080] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0081] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An evaporator provided with an evaporation chamber, said evaporation chamber having a refrigerant vapor outlet (12), characterized in that, The evaporation chamber is provided with a plurality of liquid replenishment trays (6) arranged sequentially from top to bottom. A mass transfer cavity is formed between adjacent liquid replenishment trays (6) for transferring gaseous refrigerant and connecting to the refrigerant vapor outlet (12). Each liquid replenishment tray (6) is provided with a heat transfer tube (5) for circulating cooling medium and placed horizontally. The outer side of the heat transfer tube (5) has a capillary structure for guiding the liquid refrigerant (8) in the liquid replenishment tray (6) to the upper part of the heat transfer tube (5).

2. The evaporator of claim 1, wherein, At least one of the replenishment trays (6) has an overflow port (61), and liquid refrigerant (8) overflowing from the overflow port (61) can fall into the replenishment tray (6) below.

3. The evaporator of claim 2, wherein, The overflow ports (61) of two adjacent replenishment trays (6) are horizontally staggered.

4. The evaporator of claim 1, wherein, It also includes a refrigerant return port (11) located at the top of the evaporation chamber and a return pipe (9) located inside the evaporation chamber. One end of the return pipe (9) is connected to the refrigerant return port (11), and the other end extends to the bottom of the evaporation chamber to pass through each of the replenishment trays (6). A replenishment port (91) is provided at the connection with each of the replenishment trays (6) to introduce the condensed liquid refrigerant (8) into each of the replenishment trays (6).

5. The evaporator of claim 1, wherein, The replenishment tray (6) is provided with a plurality of heat transfer tubes (5) arranged horizontally in parallel, and the horizontal direction is perpendicular to the extension direction and the vertical direction of the heat transfer tubes (5).

6. The evaporator of claim 1, wherein, The capillary structure is a fin groove structure (51) disposed on the outer wall of the heat transfer tube.

7. The evaporator of claim 2, wherein, It also includes a refrigerant return port (11) located at the top of the evaporation chamber, and a flow guide baffle (7) is provided between the refrigerant return port (11) and the heat transfer tube (5) to guide the liquid refrigerant to flow laterally.

8. The evaporator according to any one of claims 1 to 7, characterized in that Along the extension direction of the heat transfer tube (5), there is a mixing chamber at both ends of the evaporation chamber, and the two ends of the plurality of heat transfer tubes (5) are respectively connected to the mixing chambers at both ends.

9. The evaporator according to claim 8, characterized in that, It includes a main shell (1) and tube sheets (4) disposed at both ends of the main shell (1). One side of the tube sheet (4) faces the mixing chamber and the other side faces the evaporation chamber. The two ends of the heat transfer tube (5) pass through the tube sheets (4) at both ends to communicate with the mixing chamber on the corresponding side.

10. The evaporator according to claim 9, characterized in that, One end of the main body shell (1) is provided with a diversion device (2), the diversion device (2) and the tube sheet (4) enclose a first cavity, and the first cavity is divided into at least two mixing cavities by a diversion baffle (23), which are respectively a cooling medium diversion cavity and a cooling medium confluence cavity.

11. The evaporator according to claim 10, characterized in that, The other end of the main shell (1) is provided with a flow diversion device (3), which and the tube sheet (4) enclose a second cavity; the first cavity is divided into three mixing cavities arranged from top to bottom by two horizontally arranged diversion baffles (23), which are the cooling medium diversion cavity, the first flow diversion cavity, and the cooling medium confluence cavity from top to bottom; the second cavity is divided into two mixing cavities arranged from top to bottom by a flow diversion baffle (31), which are the second flow diversion cavity and the third flow diversion cavity from top to bottom; the cavity contains each of the heat transfer tubes (5) The tube groups are arranged in the following order from top to bottom: a first tube group, a second tube group, a third tube group, and a fourth tube group. The two ends of each heat transfer tube (5) in the first tube group are connected to the cooling medium distribution cavity and the second transfer cavity, respectively. The two ends of each heat transfer tube (5) in the second tube group are connected to the first transfer cavity and the second transfer cavity, respectively. The two ends of each heat transfer tube (5) in the third tube group are connected to the first transfer cavity and the third transfer cavity, respectively. The two ends of each heat transfer tube (5) in the fourth tube group are connected to the cooling medium confluence cavity and the third transfer cavity, respectively.

12. The evaporator according to claim 11, characterized in that, The main body shell (1) and the diversion device (2) are connected by a flange and clamp the tube sheet (4) between them. The main body shell (1) and the diversion device (3) are connected by a flange and clamp the tube sheet (4) between them. The diversion baffle (23) is inserted into the tube sheet (4) on the corresponding side for a sealed connection. The diversion baffle (31) is inserted into the tube sheet (4) on the corresponding side for a sealed connection.

13. The evaporator according to claim 1, characterized in that, Along the extension direction of the heat transfer tube (5), a refrigerant return port (11) is provided at the top center of the evaporation chamber, and refrigerant vapor outlets (12) are provided at the top of both sides of the refrigerant return port (11).

14. The evaporator according to claim 1, characterized in that, At least one of the heat transfer tubes (5) corresponding to the replenishment tray (6) has an interval of 5 mm to 7 mm between adjacent heat transfer tubes (5); the distance between the heat transfer tube (5) and the lower side of the adjacent upper replenishment tray (6) is between 9 mm and 12 mm; the distance between the heat transfer tube (5) and the bottom surface of the corresponding replenishment tray (6) is between 1 mm and 2 mm; the height of the overflow port (61) of the replenishment tray (6) is between 2 mm and 5 mm; the width of the fin groove structure (51) of the heat transfer tube (5) is between 0.1 mm and 1 mm; and the immersion rate of the heat transfer tube (5) in the replenishment tray (6) is between 0% and 18%.

15. An adsorption refrigeration machine, comprising an adsorption bed and a condenser, characterized in that, It also includes an evaporator as described in any one of claims 1-14, wherein the refrigerant vapor outlet (12) of the evaporator's evaporation chamber is connected to the adsorption chamber of the adsorption bed, and the refrigerant return port (11) of the evaporator's evaporation chamber is connected to the liquid outlet of the condenser.

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