Three-fluid heat exchanger and humidity control device

Abstract

To provide a three-fluid heat exchanger and a humidity control device that increase the uniformity of a hygroscopic liquid flowing on the outer surface of a heat transfer tube. [Solution] A three-fluid heat exchanger 20 has multiple heat exchange units 22 stacked vertically, each of which has a tubular heat transfer tube 16 through which a heat transfer fluid flows, a bottom plate 72 formed with slits 74 with edges 74A extending along the axial direction of the heat transfer tube 16, a radially outer upper portion of the heat transfer tube 16 positioned from one end to the other while contacting the edges 74A, a spray tray 70 that supplies hygroscopic liquid from the slits 74 down to the outer periphery of the heat transfer tube 16, and a filler 17 arranged on the spray tray 70 and bringing the hygroscopic liquid into contact with the air 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 liquid by dropping the target fluid onto the outside of a heat transfer tube through which the heat transfer fluid flows and flowing the target fluid over the surface of the heat transfer tube 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 hygroscopic liquid are brought into contact therein. This heat exchanger is a three-fluid heat exchanger in which heat exchange is performed between 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, which comes into sufficient gas-liquid contact with the air in the filler material below, and is cooled or heated again by flowing over the outer surface of the next heat transfer tube. 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 parts 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 measure to increase the wet area of ​​the outer surface of the heat transfer tube, the wet-type humidity control device of Patent Document 1 provides a tray above the heat transfer tube to evenly supply the target liquid to the heat transfer tube. The tray has a plurality of holes formed in the bottom surface along the axial direction of the heat transfer tube, 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 parts in the axial direction of the heat transfer tube where holes are formed and parts where holes are not formed, so there is room to improve 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 increase 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 configured by stacking multiple heat exchange units vertically, each heat exchange unit having a heat transfer tube through which a heat transfer fluid flows, a bottom plate formed with slits whose edges extend along the axial direction of the heat transfer tube, a radially outer upper portion of the heat transfer tube being positioned from one end to the other while contacting the edges, a spray tray that supplies a hygroscopic liquid from the slits down to the outer periphery of the heat transfer tube, and a gas-liquid contact section disposed on the spray tray and bringing the hygroscopic liquid into contact with the air to be treated.

[0010] In the three-fluid heat exchanger of the first embodiment, a slit is formed in the spray tray with an edge extending along the axial direction of the heat transfer tube, and the radially outer upper part of the heat transfer tube contacts the edge of the slit from one end to the other end, and the position between the slit position and the heat transfer tube is determined. Therefore, the hygroscopic liquid flows down the outer circumference of the heat transfer tube at positions that are continuous in the axial direction of the heat transfer tube contacting the edge of the slit. This makes it possible to increase the uniformity of the hygroscopic liquid flowing on the outer surface of the heat transfer tube, and to improve 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 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 of the heat exchange units adjacent to the other heat exchange unit vertically below.

[0012] In the three-fluid heat exchanger of the second embodiment, a heat transfer tube is arranged between the bottom plate of the spray tray and the gas-liquid contact portion of another heat exchange unit adjacent vertically below, so that multiple heat exchange units can 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, the elastic member 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 of 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 and aligned parallel to the slits.

[0016] In the four-fluid heat exchanger, a plurality of through holes are formed in the bottom plate of the spray tray in addition to the slits. Therefore, even if the slits are clogged with debris or the like, the hygroscopic liquid can flow out through the through holes, thereby preventing the hygroscopic liquid from excessively accumulating in the spray tray and overflowing.

[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, since the peripheral weir is formed along the outer periphery of the through-hole, the hygroscopic liquid remaining in the spray tray does not enter the through-hole up to the height of the peripheral weir. Therefore, in a state in which the hygroscopic liquid smoothly flows down from the slits to the heat transfer tube, the flow down of the hygroscopic liquid from the through-hole can be prevented.

[0019] In a three-fluid heat exchanger of 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 embodiment, a sub-slit is formed in the bottom plate of the spray tray in addition to the slit. Therefore, even if the slit is clogged with debris or the like, the hygroscopic liquid can be caused to flow out from the sub-slit, thereby preventing the hygroscopic liquid from excessively accumulating in the spray tray and overflowing.

[0021] The three-fluid heat exchanger of the seventh aspect of the present disclosure further includes 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, in a state in which the hygroscopic liquid flows smoothly down from the slit into the heat transfer tube, it is possible to prevent the hygroscopic liquid from flowing down from the sub-slit.

[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. Effect of the Invention

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

[0026] [Figure 1] 1 is a schematic diagram showing a configuration of a humidity control device according to an embodiment of the present invention. [Diagram 2] 1 is a schematic diagram of a processing machine equipped with a three-fluid heat exchanger of this embodiment. [Diagram 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] FIG. 2 is a perspective view of a heat exchange unit constituting the three-fluid heat exchanger of the present embodiment. [Diagram 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. 11 is a perspective view of a distribution tray according to a modified example of the present embodiment. [Figure 9] FIG. 11 is a perspective view of a scattering tray according to another modified example of the present embodiment. [Figure 10] 13A is a perspective view of a peripheral dam on a spray tray of another modified example of this embodiment, and FIG. 13B is a cross-sectional view of the vicinity of the peripheral dam. [Figure 11] 13A is a perspective view of a pair of weirs on a spray tray of another modified example of this embodiment, and FIG. 13B is a cross-sectional view of the vicinity of the pair of weirs. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 recovering the dehumidification 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 liquid.

[0031] The processor 10 and the regenerator 30 are connected by a first hygroscopic liquid pipe 51 and a second hygroscopic liquid pipe 52. The first hygroscopic liquid pipe 51 is a pipe for sending hygroscopic liquid from the processor 10 to the regenerator 30, and the second hygroscopic liquid pipe 52 is a pipe for sending hygroscopic liquid from the regenerator 30 to the processor 10. The first hygroscopic liquid pipe 51 is provided with a pump 53, and the second hygroscopic liquid pipe 52 is provided with a pump 54. By using the first hygroscopic liquid pipe 51 and the second hygroscopic liquid pipe 52, which are provided with a pump 54, 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, 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, and forcibly exhausts air from within the housing 11, and takes in the air to be processed, 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 to the space to be dehumidified.

[0033] Within the housing 11, there are provided a distributor 15, a heat transfer tube 16, a spray tray 70, packing material 17 constituting a gas-liquid contact portion, a lowermost packing material 18, a solution tank 19, and left and right side panels 26.

[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 along the lower heat transfer tubes 16 of the distributor 15, between the left and right side plates 26.

[0036] The distributor 15 drips the hygroscopic liquid from the distribution port, and supplies the hygroscopic liquid to the upper part of the three-fluid heat exchanger 20 (specifically, the spray tray 70 described later). The hygroscopic liquid supplied to the three-fluid heat exchanger 20 flows sequentially from the upper to lower parts in the three-fluid heat exchanger 20 by natural flow caused by gravity and surface tension, and falls into the solution tank 19 through the bottom-most packing material 18 of the final part. Here, natural flow means that the hygroscopic liquid flows by gravity, surface tension, etc. acting on the hygroscopic liquid, and does not require a power source such as a pump for flowing the hygroscopic liquid. The solution tank 19 receives and temporarily holds the hygroscopic liquid that has passed through the three-fluid heat exchanger 20 and the bottom-most packing material 18 and fallen.

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

[0038] In this way, three fluids, namely, the hygroscopic liquid, the heat transfer fluid, and the air to be treated, flow into the three-fluid heat exchanger 20, and heat exchange takes place between these three fluids. That is, the hygroscopic liquid is cooled by the refrigerant through the heat transfer tube 16, and the air to be treated is cooled by direct contact with the hygroscopic liquid. The temperature of the hygroscopic liquid increases by contacting the air to be treated, which has a higher temperature than the hygroscopic liquid, and by the heat of absorption (heat of condensation of the water vapor and heat of dilution of the solution) due to the absorption of water vapor in the air to be treated. In this way, the three-fluid heat exchanger 20 has a configuration in which the hygroscopic liquid, the heat transfer fluid, and the air to be treated are directly or indirectly brought into contact with each other, and the three-fluid heat exchanger 20 transfers heat and material (water), i.e., exchanges both sensible heat and latent heat.

[0039] The regenerator 30 has the same configuration as the processor 10. In the three-fluid heat exchanger 40, three fluids, namely, a hygroscopic liquid, a heat transfer medium (heat transfer fluid), and regenerative air, flow in, and heat exchange occurs between these three fluids. The hygroscopic liquid is heated by the heat transfer medium through the heat transfer tube 16, and the regenerative air is heated by direct contact with the hygroscopic liquid. In addition, the temperature of the hygroscopic liquid is lowered by contact with the regenerative air, which has a lower temperature than the hygroscopic liquid, and by negative heat absorption due to the release of moisture into the regenerative air. In this way, in the three-fluid heat exchanger 40, the hygroscopic liquid, the heat transfer medium (heat transfer fluid), and the regenerative air come into direct or indirect contact with each other, and the transfer of heat and material (water), i.e., the heat exchange of both sensible heat and latent heat, occurs.

[0040] The humidity control device 100 includes a heat pump 60 for supplying a refrigerant to the heat transfer tubes 16 of the three-fluid heat exchanger 20 and 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 includes 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 tube 63 connecting these in this order. Note that 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 as the heat transfer tubes 16 of the three-fluid heat exchanger 40 by exchanging the positions of the compressor 61 and the expansion valve 62.

[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 (stages) in the vertical direction.

[0042] As shown in Fig. 3, the spray tray 70 has a side plate 71 and a bottom plate 72. The bottom plate 72 is a rectangular plate and is arranged horizontally so as to bridge between the side plates 26. The side plates 71 are provided so as 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 plate 26 is called side plate 71A, and the side plate 71 arranged in a direction perpendicular to the side plate 71A is called side plate 71B, the side plate 71A is raised to a position higher than the 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. A portion constituting 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 the portions corresponding to the slits 74. The diffusion member 76 diffuses the hygroscopic liquid in the planar direction (toward the bottom surface of the spray tray 70) by capillary action. In each spray tray 70, the hygroscopic liquid is diffused in the planar direction while penetrating the diffusion member 76, and is supplied downward from the slits 74 to the heat transfer tubes 16 below.

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

[0046] The first plate 17A has a wave wall that extends at a first angle θ1, which is diagonally downward from the upstream side of the air to be treated to the downstream side with respect to the horizontal direction S1, and the second plate 17B has a wave wall that extends at a second angle θ2, which is diagonally upward from the upstream side of the air to be treated to the downstream side with respect to the horizontal direction S1.

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

[0048] 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 the heat transfer tubes 16 adjacent in the vertical direction are connected outside the side plates 26, and the heat transfer tubes 16 overlapping in the vertical direction are configured as a single tube that extends in a meandering manner without branching as a whole. The single heat transfer tubes 16 are arranged in multiple rows. 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 flows inside the heat transfer tubes 16 as a refrigerant. The heat transfer tubes 16 are preferably made of metal from the viewpoint of strength, and in particular, a material having corrosion resistance to hygroscopic liquids is preferable.

[0049] The outer surface of the heat transfer tube 16 is processed so as to form a gap between the slit 74 and the heat transfer tube 16, to increase the surface area, and to increase hydrophilicity. As an example, in this embodiment, a fine groove 16A can be provided in a spiral shape as shown in FIG.

[0050] The heat transfer tube 16 of one heat exchange unit 22 is disposed between the bottom plate 72 of the spread tray 70 disposed above it and the packing material 17 of the other heat exchange unit 22 adjacent vertically below it. The radially outer upper portion of the heat transfer tube 16 contacts the slit edge 74A of the slit 74 formed in the bottom plate 72 from one end to the other end between the side plates 26, thereby positioning the slit 74 and the heat transfer tube 16. The heat transfer tube 16 is in close contact with the packing material 17 by the elastic force of the elastic member 78 on the bottom plate 72 of the spread tray 70 disposed below it. The width W of the slit 74 is set to such an extent that the positioned heat transfer tube 16 does 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 tube 16. The outer diameter of the heat transfer tube 16 is smaller than the distance (spacing) between the bottom plate 72 of the spread tray 70 and the packing material 17.

[0051] (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 intake port 12 and discharged from the exhaust port 13, and the three-fluid heat exchanger 40 to take in air for regeneration through the intake port 12 and discharged from the exhaust port 13.

[0052] The hygroscopic liquid supplied to the distributor 15 of the three-fluid heat exchanger 20 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 along the outer circumferential surface of the heat transfer tube 16 from the slits 74, and is cooled by the refrigerant flowing through the heat transfer tube 16. Then, the hygroscopic liquid is supplied onto the next-stage spray tray 70 via the packing material 17. The air to be treated flows in a direction intersecting with the hygroscopic liquid in the packing material 17, and the two come into gas-liquid contact, causing the hygroscopic liquid to absorb moisture from the air to be treated.

[0053] The above-mentioned flow, cooling, and moisture absorption of the hygroscopic liquid are repeated downward, and the air to be treated is dehumidified and supplied to the target space. The hygroscopic liquid that passes through the bottom filler 18 and falls is received and temporarily stored in the solution tank 19, and is then supplied by the pump 53 to the distributor 15 of the three-fluid heat exchanger 40 via the heat exchanger 55.

[0054] 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 along the outer circumferential surface of the heat transfer tube 16 from the slit 74, and is heated by the heat medium flowing through the heat transfer tube 16. Then, the liquid is supplied onto the next-stage spray tray 70 via the packing material 17. In the packing material 17, the regenerating air flows in a direction intersecting with the hygroscopic liquid, and the two come into gas-liquid contact, causing moisture to be released from the hygroscopic liquid to the regenerating air.

[0055] The above-mentioned flowing down of the hygroscopic liquid, heating, and dehydration of the hygroscopic liquid are repeated downwards, and the hygroscopic liquid is regenerated. The hygroscopic liquid that falls 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.

[0056] In the three-fluid heat exchanger 20, 40 of this embodiment, a slit 74 whose edge extends along the axial direction of the heat transfer tube 16 is formed in the spray tray 70, and the radially outer upper portion of the heat transfer tube 16 contacts the slit edge 74A of the slit 74 from one end to the other end, thereby positioning the slit 74 and the heat transfer tube 16. Therefore, the hygroscopic liquid supplied onto the spray tray 70 flows down the outer periphery of the heat transfer tube 16 at positions continuous in the axial direction of the heat transfer tube 16 that contact the slit edge 74A of the slit 74. As a result, the uniformity of the hygroscopic liquid flowing on the outer surface of the heat transfer tube 16 can be improved compared to the case where the hygroscopic liquid flows down from holes scattered in the axial direction, and the heat exchange rate between the heat transfer fluid and the hygroscopic liquid can be improved.

[0057] In the three-fluid heat exchanger 20, 40 of this embodiment, the heat transfer tube 16 is disposed between the bottom plate 72 of the spray tray 70 and the filler 17 of another heat exchange unit 22 adjacent vertically downward to stack a plurality of heat exchange units 22, thereby improving the heat exchange rate between the heat transfer fluid and the hygroscopic liquid. Furthermore, the elastic member 78 presses the filler 17 toward the heat transfer tube 16, so that the adhesion between the heat transfer tube 16 and the filler 17 can be improved. In addition, the thickness direction (height direction) dimension of the filler 17 is set to be smaller than the height at which the filler 17 adheres to the heat transfer tube 16, and the thickness of the elastic member 78 adheres the heat transfer tube 16 and the filler 17 to each other, so that the spray tray 70 can be easily removed.

[0058] 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.

[0059] In the three-fluid heat exchangers 20 and 40 of this embodiment, the packing material 17 is formed by alternately stacking the first plates 17A and the second plates 17B, and the extension angles of the corrugated walls with respect to the horizontal direction S1 are angles θ1 and θ2, and the packing material 17 faces obliquely downward and upward from the upstream side to the downstream side of the passage 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 contacted with each other.

[0060] <Variation 1> 8, the spray tray 70 can be formed with through holes 75A. 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 even when the slits 74 are blocked, the level of the hygroscopic liquid on the spray tray 70 is less than the height of the side plate 71. Specifically, an upper limit value 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 and physical properties of the hygroscopic 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 value.

[0061] By forming the through hole 75A, even if the slit 74 is clogged with debris or the like, the hygroscopic liquid can flow out from the through hole 75A, thereby preventing the hygroscopic liquid from excessively accumulating in the spray tray 70 and spilling over the side panel 71.

[0062] Due to surface tension, the hygroscopic liquid tends to move to the area where the slit edge 74A of the slit 74 is in contact with the heat transfer tube 16, and the hygroscopic liquid does not flow down from the through-hole 75A unless there is a certain liquid level because there is nothing in contact below. Therefore, in the spray tray 70, most of the hygroscopic liquid flows down from the slit 74 along the heat transfer tube 16, and when the slit 74 is blocked, it flows down from the through-hole 75A.

[0063] 9, sub-slits 75B may 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 the through-holes 75A.

[0064] <Variation 2> As shown in Fig. 10(A), an outer periphery weir 75AW may be provided on the outer periphery of the through hole 75A described in the first modified example. As shown in Fig. 10(B), the outer periphery 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 spray tray 70 exceeds H1. Therefore, in a state in which the hygroscopic liquid flows down smoothly from the slit 74 through the heat transfer tube 16, the hygroscopic liquid can be prevented from flowing down from the through hole 75A.

[0065] Furthermore, a pair of weirs 75BW may be provided on both inner edges of the sub-slit 75B described in the first modified example, as shown in Fig. 11(A). The pair of weirs 75BW are set to a height H2 that is lower than the height H0 of the side plate 71B, as shown in Fig. 11(B). Therefore, the hygroscopic liquid does not flow down from the sub-slit 75B until the water level of the hygroscopic liquid in the spray tray 70 exceeds H2. Therefore, in a state in which the hygroscopic liquid flows down smoothly from the slit 74 through the heat transfer tube 16, it is possible to prevent the hygroscopic liquid from flowing down from the sub-slit 75B. [Explanation of symbols]

[0066] 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 Members 100 Humidity control device

Claims

1. A heat transfer tube through which a heat transfer fluid flows; 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 spray tray is provided for supplying a hygroscopic liquid from the slit to the outer periphery of the heat transfer tube; a gas-liquid contact section disposed on the spray tray and bringing the hygroscopic liquid into contact with the air 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 disposed between the bottom plate of the spread tray and the gas-liquid contact portion of the other 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 to press 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 with 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 are formed along both inner edges of the sub-slit and have a height lower than that of the side plates formed on the outer periphery of the spread tray. 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.

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