Three-fluid heat exchanger and humidity control device

Abstract

To provide a three-fluid heat exchanger and humidity control device that improves the uniformity of a hygroscopic liquid flowing on the outer surface of a heat transfer tube. [Solution] A three-fluid heat exchanger (20) is configured by stacking multiple heat exchange units (22) vertically, each of which has a heat transfer tube (16) through which a heat transfer fluid flows and which has minute irregularities formed on its outer surface from one end to the other when viewed along the axial direction, a base plate (72) in which slits (74) with edges (74A) extending along the axial direction of the heat transfer tube (16) are formed, and the radially outer upper part of the heat transfer tube (16) is positioned while contacting the edges (74A) from one end to the other, and which supplies a hygroscopic liquid from the slits (74) to the outer periphery of the heat transfer tube (16), and a filler (17) below the spray tray (70) which brings the hygroscopic liquid into contact with the gas to be treated.

Description

[Technical Field]

[0001] The present disclosure relates to a three-fluid heat exchanger and a humidity control device. [Background technology]

[0002] Conventionally, heat exchangers that perform heat exchange between a heat transfer fluid and a target fluid by dripping the target fluid onto the outside of heat transfer tubes through which the heat transfer fluid flows and allowing the target fluid to flow over the surface of the heat transfer tubes have been used in refrigerators, air conditioners, etc. For example, Patent Document 1 proposes a heat exchanger for use in a wet-type humidity control device in which heat transfer tubes and fillers are repeatedly arranged in the vertical direction, and air and a hygroscopic liquid are brought into contact therewith. This heat exchanger is a three-fluid heat exchanger in which heat is exchanged among three fluids: a heat transfer fluid, a hygroscopic liquid, and air.

[0003] In this three-fluid heat exchanger, the target liquid, a hygroscopic liquid, flows over the outer surface of the heat transfer tubes and exchanges heat with the heat source fluid flowing inside the heat transfer tubes, thereby cooling or heating the hygroscopic liquid, bringing it into sufficient gas-liquid contact with the air in the filler material below, and then flowing over the outer surface of the next lower heat transfer tube, where it is cooled or heated again.By repeating this process, the moisture absorption and release capabilities of the liquid are restored, allowing for more efficient moisture exchange.

[0004] In such a heat transfer tube, it is advantageous in terms of heat exchange efficiency that the target liquid spreads sufficiently over the outer surface of the heat transfer tube. If there are any areas on the outer surface of the heat transfer tube where the target liquid does not flow, the heat exchange rate between the heat transfer fluid and the target liquid, which is a hygroscopic liquid, will be reduced accordingly.

[0005] As a way to increase the wetted area of ​​the outer surface of the heat transfer tubes, the wet-type humidity control device of Patent Document 1 has a tray above the heat transfer tubes to evenly supply the target liquid to the heat transfer tubes. The tray has multiple holes formed in the bottom surface along the axial direction of the heat transfer tubes, and the hygroscopic liquid received by the tray is discharged downward through the holes. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6545742 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when the hygroscopic liquid is discharged downward through the holes in the bottom surface of the tray, there are areas in the axial direction of the heat transfer tube where holes are formed and areas where holes are not formed, so there is room for improvement in the uniformity of the hygroscopic liquid flowing over the outer surface of the heat transfer tube in the axial direction.

[0008] The present disclosure has been made in consideration of the above-mentioned circumstances, and aims to improve the uniformity of a hygroscopic liquid flowing on the outer surface of a heat transfer tube. [Means for solving the problem]

[0009] The three-fluid heat exchanger of the first aspect of the present disclosure is constructed by stacking multiple heat exchange units vertically, each heat exchange unit having: a heat transfer tube through which a heat transfer fluid flows and which has minute irregularities formed on its outer surface from one end to the other when viewed along the axial direction; a base plate formed with slits whose edges extend along the axial direction of the heat transfer tube, and a radially outer upper portion of the heat transfer tube which is positioned while contacting the edges from one end to the other; a spray tray which supplies a hygroscopic liquid from the slits to the outer periphery of the heat transfer tube; and a gas-liquid contact section below the spray tray which brings the hygroscopic liquid into contact with the gas to be treated.

[0010] In the three-fluid heat exchanger of the first aspect, a slit is formed in the spray tray, the edge of which extends along the axial direction of the heat transfer tube, and the radially outer upper part of the heat transfer tube contacts the edge of this slit from one end to the other, thereby determining the position between the slit and the heat transfer tube. Therefore, the hygroscopic liquid flows down the outer periphery of the heat transfer tube at positions that are continuous in the axial direction of the heat transfer tube, where the hygroscopic liquid contacts the edge of the slit. This increases the uniformity of the hygroscopic liquid flowing on the outer surface of the heat transfer tube, and improves the heat exchange rate between the heat transfer fluid and the hygroscopic liquid.

[0011] In a three-fluid heat exchanger of a second aspect of the present disclosure, the heat transfer tubes of one of the heat exchange units are arranged between the bottom plate of the spray tray and the gas-liquid contact portion of another of the heat exchange units adjacent to it vertically below.

[0012] In the three-fluid heat exchanger of the second embodiment, the heat transfer tubes are arranged between the bottom plate of the spray tray and the gas-liquid contact portion of another heat exchange unit adjacent vertically below, thereby allowing multiple heat exchange units to be stacked.

[0013] In a three-fluid heat exchanger according to a third aspect of the present disclosure, an elastic member is disposed between the spray tray and the gas-liquid contact portion, for pressing the gas-liquid contact portion toward the heat transfer tube.

[0014] In the three-fluid heat exchanger of the third aspect, the gas-liquid contact portion can be brought into stable contact with the heat transfer tube by pressing the gas-liquid contact portion toward the heat transfer tube with the elastic member.

[0015] In a three-fluid heat exchanger according to a fourth aspect of the present disclosure, a plurality of slits are formed in parallel on the bottom plate of the spray tray, and a plurality of through holes are formed between the slits so as to be aligned parallel to the slits.

[0016] In the four-part three-fluid heat exchanger, a plurality of through holes are formed in the bottom plate of the spray tray in addition to the slits, so that even if the slits are clogged with debris or the like, the hygroscopic liquid can flow out through the through holes, thereby preventing excessive accumulation and overflow of the hygroscopic liquid in the spray tray.

[0017] The three-fluid heat exchanger of the fifth aspect of the present disclosure further includes an outer periphery weir formed along the outer periphery of the through hole and having a height lower than that of the side plate formed on the outer periphery of the spray tray.

[0018] In the three-fluid heat exchanger of the fifth aspect, the peripheral weir is formed along the outer periphery of the through-hole, so that the hygroscopic liquid remaining in the spray tray does not enter the through-hole up to the height of the peripheral weir. Therefore, when the hygroscopic liquid flows smoothly down from the slits to the heat transfer tubes, the hygroscopic liquid can be prevented from flowing down from the through-holes.

[0019] In a three-fluid heat exchanger according to a sixth aspect of the present disclosure, a plurality of slits are formed in parallel on the bottom plate of the spray tray, and sub-slits are formed between the slits so as to be aligned parallel to the slits.

[0020] In the three-fluid heat exchanger of the sixth aspect, a sub-slit is formed in the bottom plate of the spray tray in addition to the slit, so that even if the slit is clogged with debris or the like, the hygroscopic liquid can flow out through the sub-slit, thereby preventing excessive accumulation and overflow of the hygroscopic liquid in the spray tray.

[0021] The three-fluid heat exchanger of the seventh aspect of the present disclosure further comprises a pair of weirs formed along both inner edges of the sub-slit and having a height lower than that of the side plates formed on the outer periphery of the distribution tray.

[0022] In the three-fluid heat exchanger of the seventh aspect, a pair of weirs is formed along both inner edges of the sub-slit, so that the hygroscopic liquid remaining in the spray tray does not enter the sub-slit up to the height of the pair of weirs. Therefore, when the hygroscopic liquid flows smoothly down from the slits to the heat transfer tubes, the hygroscopic liquid can be prevented from flowing down from the sub-slits.

[0023] A humidity control device according to an eighth aspect of the present disclosure includes the three-fluid heat exchanger according to any one of the first to fifth aspects.

[0024] According to the humidity control device of the eighth aspect, the uniformity of the hygroscopic liquid flowing on the outer surface of the heat transfer tube can be increased, and the heat exchange rate between the heat transfer fluid and the hygroscopic liquid can be improved. [Effects of the Invention]

[0025] According to the technique of the present disclosure, it is possible to improve the uniformity of the hygroscopic liquid flowing on the outer surface of the heat transfer tube. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a schematic diagram showing the configuration of a humidity control device according to an embodiment of the present invention. [Figure 2] 1 is a schematic diagram of a processing machine equipped with a three-fluid heat exchanger of this embodiment. [Figure 3] FIG. 2 is an exploded perspective view of a heat exchange unit constituting the three-fluid heat exchanger of the present embodiment. [Figure 4] 1 is a perspective view of a heat exchange unit constituting the three-fluid heat exchanger of the present embodiment. FIG. [Figure 5] 2 is a partial cross-sectional view of a heat exchange unit constituting the three-fluid heat exchanger of the present embodiment. FIG. [Figure 6] FIG. 2 is a perspective view of the filler of the present embodiment. [Figure 7] FIG. 2 is a partial side view of the heat transfer tube of the present embodiment. [Figure 8] FIG. 10 is a perspective view of a sprinkling tray according to a modified example of the present embodiment. [Figure 9] FIG. 10 is a perspective view of a sprinkling tray according to another modified example of the present embodiment. [Figure 10] 10A is a perspective view of a peripheral weir on a spray tray of another modified example of this embodiment, and FIG. 10B is a cross-sectional view of the vicinity of the peripheral weir. [Figure 11] 10A is a perspective view of a pair of weirs on a spray tray of another modified example of this embodiment, and FIG. 10B is a cross-sectional view of the vicinity of the pair of weirs. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, a three-fluid heat exchanger and a humidity control device according to the present disclosure will be described with reference to the drawings.

[0028] 1, a humidity control apparatus 100 according to the present disclosure has a processor 10 that takes in air to be treated and brings it into contact with a hygroscopic liquid to dehumidify the air to be treated, and a regenerator 30 that regenerates the hygroscopic liquid used for the dehumidification treatment in the processor 10. Here, regeneration of the hygroscopic liquid refers to increasing the concentration of the hygroscopic liquid that has been diluted by absorbing moisture in the air to be treated due to dehumidification, thereby restoring the dehumidifying ability of the hygroscopic liquid.

[0029] The processor 10 discharges the dehumidified air into the space to be dehumidified, and the regenerator 30 discharges the air used for regeneration outside the space to be dehumidified.

[0030] As an example of the hygroscopic liquid, a lithium chloride (LiCl) aqueous solution can be used. Note that the hygroscopic liquid is not limited to a lithium chloride aqueous solution, and may be any liquid with a saturated water vapor pressure lower than that of water at the same temperature, such as lithium bromide, calcium chloride, magnesium chloride, an aqueous salt solution, an ionic liquid, a highly hygroscopic polyhydric alcohol, or other hygroscopic liquids.

[0031] The processor 10 and the regenerator 30 are connected by a first hygroscopic liquid pipeline 51 and a second hygroscopic liquid pipeline 52. The first hygroscopic liquid pipeline 51 is a pipeline for sending hygroscopic liquid from the processor 10 to the regenerator 30, and the second hygroscopic liquid pipeline 52 is a pipeline for sending hygroscopic liquid from the regenerator 30 to the processor 10. The first hygroscopic liquid pipeline 51 is provided with a pump 53, and the second hygroscopic liquid pipeline 52 is provided with a pump 54. By using the first hygroscopic liquid pipeline 51 and the second hygroscopic liquid pipeline 52 to circulate the hygroscopic liquid between the processor 10 and the regenerator 30, the hygroscopic liquid used in the processor 10 can be regenerated in the regenerator 30, and the hygroscopic liquid regenerated in the regenerator 30 can be returned to the processor 10.

[0032] FIG. 2 is a cross-sectional view of the processor 10, taken perpendicular to the longitudinal direction of the heat transfer tube 16. The configuration of the processor 10 will be described below with reference to FIGS. 1 and 2. The processor 10 includes a housing 11 having an intake port 12 and an exhaust port 13. The exhaust port 13 has an exhaust fan 14, which forcibly exhausts air from the housing 11, and also takes in the air to be treated, such as return air from the space to be dehumidified or outside air, into the housing 11 through the intake port 12. The exhaust port 13 is connected to the space to be dehumidified through a duct or the like, and the dehumidified air is discharged from the exhaust port 13 into the space to be dehumidified.

[0033] Distributor 15, heat transfer tubes 16, spray tray 70, packing material 17, bottom packing material 18, solution tank 19, and left and right side panels 26 are provided within housing 11. The gas-liquid contact portion refers to the portion where gas and liquid come into contact, and the liquid may be in the form of a liquid film, droplets, or the like, and includes the surface of heat transfer tube 16 where a liquid film is formed and the liquid film comes into contact with the gas. Packing material 17 that constitutes the gas-liquid contact portion is provided to increase the area where liquid and gas come into contact (gas-liquid contact area), and is not essential if a sufficient gas-liquid contact area can be secured without packing material, for example, when heat transfer tubes 16 are arranged at a high density.

[0034] The side plates 26 constitute the left and right outer walls of the three-fluid heat exchanger 20, and are configured by a pair of plate members arranged to face each other in the vertical direction.

[0035] The distributor 15 is a roughly tray-shaped member disposed above the three-fluid heat exchanger 20, and has a plurality of distribution ports formed on its underside through which the hygroscopic liquid drips downward. The distribution ports are formed between the left and right side plates 26 and along the heat transfer tubes 16 in the lower row of the distributor 15.

[0036] The distributor 15 drips the hygroscopic liquid from its distribution port, supplying the hygroscopic liquid to the upper part of the three-fluid heat exchanger 20 (specifically, the spray tray 70 described below). The hygroscopic liquid supplied to the three-fluid heat exchanger 20 flows sequentially from the upper to the lower parts within the three-fluid heat exchanger 20 by gravity and surface tension, passing through the bottom-most packing material 18 of the final part and dropping into the solution tank 19. Here, gravity flow refers to the flow of the hygroscopic liquid being caused by gravity, surface tension, etc. acting on the hygroscopic liquid, and does not require a power source such as a pump to flow the hygroscopic liquid. The solution tank 19 receives and temporarily stores the hygroscopic liquid that has passed through the three-fluid heat exchanger 20 and the bottom-most packing material 18 and dropped.

[0037] The arrows in Figure 2 indicate the flow of air. The air to be treated is taken into the housing 11 through the intake port 12, flows horizontally within the housing 11 by the drive of the exhaust fan 14, and is discharged from the exhaust port 13 into the space to be dehumidified.

[0038] As described above, three fluids, namely, a hygroscopic liquid, a heat transfer fluid, and the air to be treated, flow into the three-fluid heat exchanger 20, and heat exchange occurs among these three fluids. That is, the hygroscopic liquid is cooled by the refrigerant via the heat transfer tubes 16, and the air to be treated is cooled by direct contact with the hygroscopic liquid. The temperature of the hygroscopic liquid also rises due to contact with the air to be treated, which has a higher temperature than the hygroscopic liquid, and due to the heat of absorption (heat of condensation of the water vapor and heat of dilution of the solution) resulting from the absorption of water vapor in the air to be treated. As described above, the three-fluid heat exchanger 20 has a configuration that allows the hygroscopic liquid, the heat transfer fluid, and the air to be treated to come into direct or indirect contact with each other. The three-fluid heat exchanger 20 transfers heat and material (water), i.e., exchanges both sensible and latent heat.

[0039] The regenerator 30 has a similar configuration to the processor 10. In the three-fluid heat exchanger 40, three fluids—a hygroscopic liquid, a heat transfer medium (heat transfer fluid), and regeneration air—flow in, and heat exchange occurs among these three fluids. The hygroscopic liquid is heated by the heat transfer medium via the heat transfer tubes 16, and the regeneration air is heated by direct contact with the hygroscopic liquid. The temperature of the hygroscopic liquid also decreases due to contact with the regeneration air, which has a lower temperature than the hygroscopic liquid, and due to negative heat absorption resulting from the release of moisture into the regeneration air. Thus, in the three-fluid heat exchanger 40, the hygroscopic liquid, the heat transfer medium (heat transfer fluid), and the regeneration air come into direct or indirect contact with each other, resulting in the transfer of heat and material (water), i.e., the exchange of both sensible and latent heat.

[0040] The humidity control apparatus 100 is equipped with a heat pump 60 for supplying a refrigerant to the heat transfer tubes 16 of the three-fluid heat exchanger 20 and for supplying a heat medium to the heat transfer tubes 16 of the three-fluid heat exchanger 40. Each heat transfer tube 16 constitutes a heat exchanger of the heat pump 60. That is, the heat pump 60 is composed of the heat transfer tubes 16 of the three-fluid heat exchanger 20 functioning as an evaporator, a compressor 61, the heat transfer tubes 16 of the three-fluid heat exchanger 40 functioning as a condenser, an expansion valve 62, and a heat medium fluid pipe 63 connecting these in this order. Note that by exchanging the positions of the compressor 61 and the expansion valve 62, the heat pump 60 can also cause the heat transfer tubes 16 of the three-fluid heat exchanger 20 to function as a condenser and also as the heat transfer tubes 16 of the three-fluid heat exchanger 40.

[0041] The three-fluid heat exchanger 20 and the three-fluid heat exchanger 40 have the same configuration, and therefore the configuration will be described below using the three-fluid heat exchanger 20 as an example. In the three-fluid heat exchanger 20, heat exchange units 22 each having a filler 17, a spray tray 70, and a heat transfer tube 16 are arranged in multiple sets (tiers) in the vertical direction.

[0042] As shown in FIG. 3, the spray tray 70 has side plates 71 and a bottom plate 72. The bottom plate 72 is rectangular and is arranged horizontally so as to bridge between the side plates 26. The side plates 71 are provided to rise from each of the four sides of the bottom plate 72. If the side plate 71 arranged in a direction along the side plates 26 is referred to as side plate 71A, and the side plate 71 arranged in a direction perpendicular to side plate 71A is referred to as side plate 71B, then side plate 71A rises to a higher position than side plate 71B.

[0043] A plurality of slits 74 are formed in the bottom plate 72 from one side of the side plate 26 to the other side. The slits 74 extend along the axial direction of the heat transfer tubes 16, which will be described later. The plurality of slits 74 (six in this embodiment) are arranged in parallel at equal intervals. The portion that forms the outer edge of the slits 74 is referred to as a slit edge 74A. The slits 74 are also formed to extend into the side plate 71A.

[0044] As shown in Fig. 5, a diffusion member 76 is laid on the upper surface of the bottom plate 72. A nonwoven fabric can be used as the diffusion member 76. The diffusion member 76 has slits 76A formed in portions corresponding to the slits 74. The diffusion member 76 diffuses the hygroscopic liquid in a planar direction (toward the bottom surface of the spraying tray 70) by capillary action. In each spraying tray 70, the hygroscopic liquid is diffused in a planar direction while permeating the diffusion member 76, and is then supplied downward through the slits 74 to the heat transfer tubes 16 below.

[0045] A gas-liquid contact space R is formed between the spray tray 70 and the heat transfer tubes 16. Elastic members 78 are provided at multiple locations along the side plate 71B on the spray tray 70, and fillers 17 are placed in the gas-liquid contact space R on the elastic members 78. The fillers 17 are pressed toward the heat transfer tubes 16 by the elastic members 78. The filler 17 as a whole has a rectangular parallelepiped shape that covers the bottom plate 72. FIG. 6 shows a perspective view of the filler 17. In order to increase the surface area per unit volume, the filler 17 is formed by alternately stacking first plates 17A and second plates 17B, each processed into a corrugated, uneven shape, in the axial direction of the heat transfer tubes 16. The direction in which the concaves or convexes of the corrugated unevenness extend is referred to as the extension direction of the wave wall.

[0046] The corrugated walls of the first plate 17A extend at a first angle θ1 that is obliquely downward relative to the horizontal direction S1 from the upstream side to the downstream side of the air to be treated, and the corrugated walls of the second plate 17B extend at a second angle θ2 that is obliquely upward relative to the horizontal direction S1 from the upstream side to the downstream side of the air to be treated. This structure adjusts the flow direction of the liquid and promotes rectification of the passing gas and contact between the liquid and gas.

[0047] The filler 17 can be made by bonding together sheets (plates) of hydrophilic cellulose-based materials, glass fiber, ceramic fiber, etc., or by integrating cellulose, glass fiber, ceramic fiber, etc. with a binder.

[0048] In addition, if no filler 17 is placed in the gas-liquid contact space R, the hygroscopic liquid present in the gas-liquid contact space R will come into contact with the gas while falling vertically as a liquid film or droplets, and the gas-liquid contact space R will function as a gas-liquid contact section.

[0049] The ends of the straight portions of the heat transfer tubes 16 extending in the left-right direction (horizontal direction) are held by the side plates 26, and adjacent heat transfer tubes 16 in the vertical direction are connected outside the side plates 26. The heat transfer tubes 16 overlapping in the vertical direction are configured as a single tube that extends in a serpentine manner without branching. A plurality of rows of the single heat transfer tube 16 are arranged. In this embodiment, an example is given in which there are six heat transfer tubes 16 and the heat transfer fluid is branched into six, but the number of branches is set according to the flow rate of the heat transfer fluid. The heat transfer fluid as a refrigerant flows inside the heat transfer tubes 16. The heat transfer tubes 16 are preferably made of metal from the standpoint of strength, and in particular, a material that is corrosion-resistant to hygroscopic liquids is preferable.

[0050] The outer surface (outer circumferential surface) of the heat transfer tube 16 is processed to provide fine irregularities 16A to form gaps between the slits 74 and the heat transfer tube 16, to increase the surface area, and to promote heat exchange between the fluid outside the tube (hygroscopic liquid), the fluid inside the tube (heat transfer fluid), and the gas to be treated. As shown in FIG. 7(A), the fine irregularities 16A appear as irregularities when viewed in a cross section of the heat transfer tube 16 along the axial direction S, and are formed from one end of the axial direction S to the other. The protruding height or depth H of the fine irregularities 16A from the outer surface of the heat transfer tube 16, or the depth H from the outer surface, is approximately 1.0 mm to 1.8 mm, and the pitch P of the irregularities is approximately 0.7 mm to 1.3 mm. The width W in the axial direction S depends on the pitch P of the irregularities and the shape of the irregularities. The fine irregularities can be formed by spiral grooves 16A (see Figure 7(A)), spiral fins 16B (see Figure 7(B)), annular fins 16C (see Figure 7(C)), and protrusions 16D (see Figure 7(D)).

[0051] The heat transfer tubes 16 of one heat exchange unit 22 are disposed between the bottom plate 72 of the spray tray 70 disposed above it and the packing material 17 of another heat exchange unit 22 adjacent thereto vertically below. The radially outer upper portions of the heat transfer tubes 16 contact the slit edges 74A of the slits 74 formed in the bottom plate 72 from one end to the other between the side plates 26, thereby positioning the slits 74 and the heat transfer tubes 16. The heat transfer tubes 16 are tightly attached to the packing material 17 by the elastic force of the elastic members 78 on the bottom plate 72 of the spray tray 70 disposed below them. The width W of the slits 74 is set to a value such that the positioned heat transfer tubes 16 do not protrude from the upper surface of the bottom plate 72, and is set according to the thickness of the bottom plate 72 and the outer diameter of the heat transfer tubes 16. The outer diameter of the heat transfer tubes 16 is smaller than the distance (spacing) between the bottom plate 72 of the spray tray 70 and the packing material 17.

[0052] (Action and effect) In the humidity control device 100 described above, operation of the heat pump 60 causes a refrigerant to flow through the heat transfer tubes 16 of the three-fluid heat exchanger 20, and a heat medium to flow through the heat transfer tubes 16 of the three-fluid heat exchanger 40, operation of the pump 54 supplies a hygroscopic liquid to the distributor 15 of the three-fluid heat exchanger 20, and operation of the pump 53 supplies a hygroscopic liquid to the distributor 15 of the three-fluid heat exchanger 40. Furthermore, operation of the fan 14 causes the three-fluid heat exchanger 20 to take in air to be treated through the air inlet 12 and discharged through the air outlet 13, and the three-fluid heat exchanger 40 to take in air for regeneration through the air inlet 12 and discharged through the air outlet 13.

[0053] The hygroscopic liquid supplied to the distributor 15 of the three-fluid heat exchanger 20 is supplied from the distribution port onto the uppermost spray tray 70. The hygroscopic liquid supplied onto the spray tray 70 is diffused by the diffusion member 76 on the spray tray 70, flows down through the slits 74 along the outer circumferential surfaces of the heat transfer tubes 16, and is cooled by the refrigerant flowing through the heat transfer tubes 16. The hygroscopic liquid then passes through the packing material 17 and is supplied onto the next-stage spray tray 70. The air to be treated flows through the packing material 17 in a direction intersecting with the hygroscopic liquid, and the two come into gas-liquid contact, causing the hygroscopic liquid to absorb moisture from the air to be treated.

[0054] The above-mentioned flowing down of the hygroscopic liquid, cooling, and moisture absorption are repeated downward, and the air to be treated is dehumidified and supplied to the target space. The hygroscopic liquid that has passed through the lowest filler 18 and fallen down is The fluid is received and temporarily stored in a tank 19, and is then supplied by a pump 53 to the distributor 15 of the three-fluid heat exchanger 40 via a heat exchanger 55.

[0055] The hygroscopic liquid supplied to the distributor 15 of the three-fluid heat exchanger 40 is supplied from the distribution port onto the top-stage spray tray 70. The hygroscopic liquid supplied onto the spray tray 70 is diffused by the diffusion member 76 on the spray tray 70, flows down through the slits 74 along the outer circumferential surfaces of the heat transfer tubes 16, and is heated by the heat medium flowing through the heat transfer tubes 16. The hygroscopic liquid then passes through the packing material 17 and is supplied onto the next-stage spray tray 70. Regeneration air flows through the packing material 17 in a direction intersecting with the hygroscopic liquid, and as a result of gas-liquid contact between the two, moisture is released from the hygroscopic liquid to the regeneration air.

[0056] The above-mentioned flowing down of the hygroscopic liquid, heating, and moisture release are repeated downwards, and the hygroscopic liquid is regenerated. The hygroscopic liquid that falls after passing through the lowest packing material 18 is received and temporarily stored in the solution tank 19, and is then supplied by the pump 54 to the distributor 15 of the three-fluid heat exchanger 20 via the heat exchanger 55.

[0057] In the three-fluid heat exchangers 20 and 40 of this embodiment, slits 74 are formed in the spray tray 70, with edges extending along the axial direction of the heat transfer tubes 16. The radially outer upper portions of the heat transfer tubes 16 contact a slit edge 74A of the slits 74 from one end to the other, thereby positioning the slits 74 and the heat transfer tubes 16. Therefore, the hygroscopic liquid supplied onto the spray tray 70 flows down the outer periphery of the heat transfer tubes 16 at consecutive positions in the axial direction of the heat transfer tubes 16 that are in contact with the slit edge 74A of the slits 74. This makes it possible to increase the uniformity of the hygroscopic liquid flowing over the outer surface of the heat transfer tubes 16, compared to when the hygroscopic liquid flows down from holes scattered in the axial direction, thereby improving the heat exchange rate between the heat transfer fluid and the hygroscopic liquid.

[0058] Furthermore, in the three-fluid heat exchangers 20, 40 of this embodiment, the heat transfer tubes 16 are disposed between the bottom plate 72 of the spray tray 70 and the filler 17 of another heat exchange unit 22 adjacent vertically below, thereby stacking multiple heat exchange units 22 and improving the heat exchange rate between the heat transfer fluid and the hygroscopic liquid. Furthermore, the elastic members 78 press the filler 17 toward the heat transfer tubes 16, thereby improving the adhesion between the heat transfer tubes 16 and the filler 17. Furthermore, the thickness (height) dimension of the filler 17 is set to be smaller than the height at which the filler 17 is in close contact with the heat transfer tubes 16, and the thickness of the elastic members 78 causes the heat transfer tubes 16 and the filler 17 to be in close contact with each other, thereby making it easier to remove the spray tray 70.

[0059] Furthermore, since the filler 17 is pressed toward the heat transfer tubes 16 by the elastic member 78, the filler 17 can be brought into stable contact with the heat transfer tubes 16.

[0060] In the three-fluid heat exchangers 20 and 40 of this embodiment, the packing material 17 is formed by alternately stacking first plates 17A and second plates 17B, and the extension angles of the corrugated walls relative to the horizontal direction S1 are angles θ1 and θ2, and the packing material 17 faces diagonally downward and upward from the upstream side to the downstream side of the air to be treated. By configuring the packing material 17 in this way, the hygroscopic liquid and the air to be treated can be efficiently brought into contact with each other.

[0061] <Variation 1> As shown in FIG. 8, through holes 75A can be formed in the spray tray 70. The through holes 75A are formed between adjacent slits 74 so as to be aligned parallel to the slits 74. The through holes 75A are preferably formed in the middle between adjacent slits 74. The shape of the through holes 75A may be any shape, such as a perfect circle, an ellipse, or a polygon. The total opening area of ​​the through holes 75A is adjusted so that the level of the hygroscopic liquid on the spray tray 70 is less than the height of the side plate 71 even when the slits 74 are blocked. Specifically, an upper limit for the level of the hygroscopic liquid is determined, and the total area of ​​the holes is determined based on various conditions such as the flow rate of the hygroscopic liquid, the physical properties of the liquid including viscosity, and the resistance of the through holes 75A so that the level of the hygroscopic liquid does not exceed the upper limit.

[0062] By forming the through-holes 75A, even if the slits 74 are clogged with dust or the like, the hygroscopic liquid can be made to flow out from the through-holes 75A, and it is possible to prevent the hygroscopic liquid from excessively accumulating in the spraying tray 70 and overflowing beyond the side plate 71. In addition, gas can pass through the through-holes 75. Therefore, the gas to be treated can enter and exit the multiple spaces partitioned by the spraying tray 70.

[0063] Due to surface tension, the hygroscopic liquid tends to move to the area where the slit edges 74A of the slits 74 come into contact with the heat transfer tubes 16, and the hygroscopic liquid will not flow down from the through-holes 75A unless there is a certain liquid level because there is nothing in contact below. Therefore, in the spraying tray 70, most of the hygroscopic liquid flows down from the slits 74 along the heat transfer tubes 16, and when the slits 74 are blocked, it begins to flow down from the through-holes 75A.

[0064] 9, sub-slits 75B can be formed in the spray tray 70 instead of the through-holes 75A. The sub-slits 75B are formed between adjacent slits 74 so as to be aligned parallel to the slits 74. The sub-slits 75B are preferably formed in the middle between adjacent slits 74. The total opening area of ​​the sub-slits 75B is determined in the same manner as that of the through-holes 75A.

[0065] <Variation 2> As shown in Fig. 10(A), a peripheral weir 75AW may be provided on the outer periphery of the through-hole 75A described in Modification 1. As shown in Fig. 10(B), the peripheral weir 75AW is set to a height H1 that is lower than the height H0 of the side plate 71B. Therefore, the hygroscopic liquid does not flow down from the through-hole 75A until the water level of the hygroscopic liquid in the spraying tray 70 exceeds H1. Therefore, when the hygroscopic liquid flows down smoothly from the slits 74 through the heat transfer tubes 16, it is possible to prevent the hygroscopic liquid from flowing down from the through-hole 75A.

[0066] Furthermore, as shown in Fig. 11(A), a pair of weirs 75BW may be provided on both inner edges of the sub-slit 75B described in Modification 1. As shown in Fig. 11(B), the pair of weirs 75BW are set at a height H2 that is lower than the height H0 of the side plate 71B. Therefore, the hygroscopic liquid does not flow down from the sub-slit 75B until the level of the hygroscopic liquid in the spraying tray 70 exceeds H2. Therefore, when the hygroscopic liquid flows smoothly down from the slit 74 along the heat transfer tube 16, the hygroscopic liquid can be prevented from flowing down from the sub-slit 75B.

[0067] Furthermore, in this embodiment, the three-fluid heat exchangers 20, 40 are applied to a humidity control device, but they can also be applied to an absorption chiller or a falling film heat exchanger that uses a hygroscopic liquid as the outer tube fluid. When applied to an absorption chiller that has four chambers, namely a condenser, an evaporator, a regenerator, and an absorber, the three-fluid heat exchanger of the present invention can be applied to the absorber and the regenerator. The hygroscopic liquid of the present invention is a concept that includes the absorbing liquid used in an absorption chiller, and if the refrigerant is water, the gas to be treated in this case will be water vapor. [Explanation of symbols]

[0068] 16 Heat transfer tube 17 Filler (gas-liquid contact area) 17A First plate 17B Second board 20 Three-fluid heat exchanger 22 Heat Exchange Unit 40 Three-fluid heat exchanger 70 Spreading Tray 72 Bottom plate 74 Slit 74A Slit edge (edge) 75A through hole 75AW Outer Weir 75B Sub-slit 75BW Pair of Weirs 78 Elastic Member 100 Humidity control device

Claims

1. a heat transfer tube through which a heat transfer fluid flows and which has minute irregularities formed on its outer surface from one end to the other end in a cross section viewed along its axial direction; a spray tray in which a slit having an edge extending along the axial direction of the heat transfer tube is formed in a bottom plate, and a radially outer upper portion of the heat transfer tube is positioned while contacting the edge from one end to the other end, and a hygroscopic liquid is supplied from the slit to flow down to the outer periphery of the heat transfer tube; a gas-liquid contact section below the spray tray that brings the hygroscopic liquid into contact with the gas to be treated; A plurality of heat exchange units having the above structure are stacked vertically. Three-fluid heat exchanger.

2. The heat transfer tube of one of the heat exchange units is arranged between the bottom plate of the spray tray and the gas-liquid contact portion of another heat exchange unit adjacent thereto vertically below. The three-fluid heat exchanger according to claim 1 .

3. an elastic member is disposed between the spray tray and the gas-liquid contact portion, the elastic member pressing the gas-liquid contact portion toward the heat transfer tube; The three-fluid heat exchanger according to claim 2 .

4. A plurality of the slits are formed in parallel on the bottom plate of the spray tray, and a plurality of through holes are formed between the slits so as to be aligned parallel to the slits. The three-fluid heat exchanger according to claim 1 .

5. Further provided is an outer periphery weir formed along the outer periphery of the through hole and having a height lower than the side plate formed on the outer periphery of the spray tray; The three-fluid heat exchanger according to claim 4.

6. A plurality of the slits are formed in parallel on the bottom plate of the spray tray, and sub-slits are formed between the slits so as to be aligned parallel to the slits. The three-fluid heat exchanger according to claim 1 .

7. A pair of weirs formed along both inner edges of the sub-slit and having a height lower than that of the side plates formed on the outer periphery of the spray tray are further provided. The three-fluid heat exchanger according to claim 6.

8. A humidity control device comprising the three-fluid heat exchanger according to any one of claims 1 to 7.

Images