JP2017156041A - Heat exchange system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchange system capable of achieving size reduction.SOLUTION: A heat exchange system 10 includes: a first heat exchanger 100 which has a plurality of plates 121 laminated and arranged having an interval from each other, and in which a refrigerant flow passage in which a refrigerant circulates and a cold water flow passage in which cold water circulates are formed alternately by the plurality of plates 121; a refrigerant supply part 80 for supplying the refrigerant to the refrigerant flow passage of the first heat exchanger 100; a cold water supply part 90 for supplying the cold water in the cold water flow passage of the first heat exchanger 100; and a gas-liquid separation part 30 for separating a gas phase component from the refrigerant which has passed the refrigerant flow passage; and a second heat exchanger 300 having a heat transfer pipe 310 with which a liquid phase component of the refrigerant which has passed the gas-liquid separation part 30 comes into contact.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a heat exchange system.

  One type of evaporator for a cooling device such as a refrigerator is a plate heat exchanger. Since the plate type heat exchanger has a large flow path cross-sectional area per volume of the heat exchanger, the heat transfer coefficient is high, and the size of the heat exchanger itself can be reduced.

  As such a plate-type heat exchanger, a plate-type heat exchanger described in Patent Document 1 below is known. This plate heat exchanger performs heat exchange between the cold water introduced into the plate heat exchanger and the refrigerant. The introduced refrigerant evaporates by absorbing heat from the cold water, becomes refrigerant gas, and is discharged from the plate heat exchanger.

Japanese Patent No. 3658677

  However, the plate heat exchanger as in Patent Document 1 is configured to evaporate a refrigerant liquid as a refrigerant and discharge it as a refrigerant gas. For this reason, during the heat exchange, the refrigerant is in a two-phase flow state in which the refrigerant liquid and the refrigerant gas are mixed. When the evaporation of the refrigerant in the plate heat exchanger proceeds, the ratio of the refrigerant gas to the refrigerant liquid in the two-phase flow refrigerant becomes too high, so that the heat transfer coefficient is extremely lowered. As a result, an excessive heat transfer area is required, and the size of the heat exchanger itself is increased.

  An object of this invention is to provide the heat exchange system which can aim at size reduction.

  The heat exchange system according to the first aspect includes a plurality of plates stacked and spaced apart from each other, and the plurality of plates alternate between a refrigerant flow path through which a refrigerant flows and a cold water flow path through which cold water flows. A first heat exchanger formed on the first heat exchanger, a refrigerant supply unit that supplies the refrigerant to the refrigerant flow path of the first heat exchanger, and the cold water to the cold water flow path of the first heat exchanger. A second unit having a cold water supply unit, a gas-liquid separation unit that separates a gas phase from the refrigerant that has passed through the refrigerant flow path, and a heat transfer tube that contacts the liquid phase of the refrigerant that has passed through the gas-liquid separation unit. Provide with heat exchanger.

  In this aspect, the first heat exchanger performs gas-liquid separation of the two-phase flow refrigerant discharged from the first heat exchanger and further evaporates the liquid phase of the separated refrigerant in the second heat exchanger. Therefore, the heat exchange from the refrigerant to the cold water can be sufficiently performed in a limited area space.

  A heat exchange system according to a second aspect is a two-phase flow that is disposed above the first heat exchanger and distributes the refrigerant that has passed through the refrigerant flow path from the first heat exchanger to the gas-liquid separation unit. The heat exchange according to the first aspect, further comprising: a refrigerant supply unit; and a liquid phase supply unit that is disposed above the second heat exchanger and supplies the liquid phase component of the refrigerant to the second heat exchanger. System.

  In this aspect, since the two-phase flow refrigerant supply unit is disposed above the first heat exchanger and the liquid phase supply unit is disposed above the second heat exchanger, the second heat exchange is performed from the first heat exchanger. The conduction path of the refrigerant to the vessel can be shortened.

  The heat exchange system according to the third aspect is the heat exchange system according to the first or second aspect, further including a spray unit that sprays the liquid phase component, and sprays the liquid phase component from above the heat transfer tube.

  In this embodiment, the liquid phase can be uniformly dispersed from above the heat transfer tube.

  The heat exchange system according to a fourth aspect is the heat exchange system according to any one of the first to third aspects, wherein the heat transfer tubes are arranged so as to extend in the horizontal direction, and are composed of a plurality of heat transfer tubes arranged vertically. It is.

  In this aspect, the liquid phase component of the refrigerant can be brought into contact over a wide range of the plurality of heat transfer tubes.

  In the heat exchange system according to a fifth aspect, the cold water supply unit supplies any one of the first to fourth supplies the cold water to the heat transfer pipe of the second heat exchanger in parallel with the first heat exchanger. It is a heat exchange system of the aspect.

  In this aspect, since heat exchange can be performed in parallel in the first heat exchanger and the second heat exchanger, high-speed heat exchange processing is possible.

  The heat exchange system according to the sixth aspect further includes a pump below the second heat exchanger, and pumps the liquid phase of the refrigerant accumulated in the lower part of the second heat exchanger, It is the heat exchange system of the aspect in any one of the 1st to 5th made to contact a heat exchanger tube.

  In this aspect, since it can suppress that the liquid phase part of a refrigerant | coolant accumulates in the lower part of a 2nd heat exchanger, liquid film type heat exchange can be maintained. Furthermore, since the liquid phase content of the refrigerant accumulated in the lower part of the second heat exchanger is brought into contact with the heat transfer tube again, the liquid phase content accumulated in the lower part of the second heat exchanger can be reused.

  In the heat exchange system according to a seventh aspect, the second heat exchanger further includes a refrigerant storage section that stores a liquid phase component of the refrigerant in a lower portion thereof, and at least the heat transfer tube is disposed inside the refrigerant storage section. It is the heat exchange system according to any one of the first to fifth aspects in which a part is arranged.

  In this aspect, it is possible to perform full liquid heat exchange at least in the lower part of the second heat exchanger.

  According to the heat exchange system of the present invention, a heat exchange system with a reduced size can be provided.

It is explanatory drawing which shows the concept of the heat exchange between the cold water and the refrigerant | coolant in the heat exchange system 10 of 1st embodiment of this invention. It is a figure explaining the structure of a counter-flow type plate-type heat exchanger 920. FIG. It is a graph which shows the heat transfer coefficient curve of the plate-type heat exchanger 920. It is a figure which shows the structure of the heat exchange system 10 in 1st embodiment which concerns on this invention. It is a perspective view of the 1st heat exchanger 100 in a first embodiment concerning the present invention. It is a figure which shows the structure of the heat exchanger tube type heat exchanger in 1st embodiment which concerns on this invention. It is a figure which shows the structure of heat exchange system 10 'in 2nd embodiment which concerns on this invention.

  Hereinafter, various embodiments according to the present invention will be described with reference to the drawings.

"First embodiment"
1st Embodiment of the heat exchange system which concerns on this invention is described with reference to FIGS.

  FIG. 1 shows a concept of heat exchange between cold water and a refrigerant in the heat exchange system 10 of the present embodiment.

  The heat exchange system 10 includes a refrigerant inlet 40 for introducing the refrigerant liquid Cl, a cold water inlet 50 for introducing the cold water Wi, a refrigerant outlet 60 for discharging the refrigerant gas Cg, a cold water outlet 70 for discharging the cold water Wo, and the heat exchanger 20. ing.

  In the present embodiment, the refrigerant liquid Cl that is a saturated liquid is introduced from the refrigerant inlet 40 and the refrigerant gas Cg that is a saturated gas is discharged from the refrigerant outlet 60. That is, the refrigerant liquid Cl of the refrigerant introduced into the heat exchanger 20 evaporates into a gas by absorbing heat from the cold water Wi introduced into the heat exchanger 20, and the refrigerant gas Cg from the plate heat exchanger. As discharged. When the heat exchange system 10 is used for a refrigerator, the refrigerant gas Cg discharged to the refrigerant outlet 60 is guided to the compressor.

  The cold water Wi introduced from the cold water inlet 50 is cooled by taking heat away from the refrigerant liquid Cl introduced into the heat exchanger 20 and discharged from the cold water outlet 70 as the cold water Wo.

  The heat exchange system 10 includes a first heat exchanger 100 and a second heat exchanger 300 as the heat exchanger 20. In the case of the present embodiment, the first heat exchanger 100 is a counter-flow plate heat exchanger, and the second heat exchanger 300 is a heat transfer tube heat exchanger.

  Here, before explaining the detailed structure of the heat exchange system 10, it is not a heat exchange system provided with the first heat exchanger 100 and the second heat exchanger 300, but a heat exchange constituted by a single plate heat exchanger 920. The system will be described. The plate-type heat exchanger 920 has the same basic structure as the plate-type heat exchanger constituting the first heat exchanger 100, but the length of the plate-type heat exchanger in the X-axis direction is different. The length of the plate heat exchanger 920 in the X-axis direction is Lf so that the refrigerant liquid Cl can be sufficiently vaporized.

  The structure of the counter flow type plate heat exchanger 920 will be briefly described with reference to FIG. As shown in FIG. 2, in the plate heat exchanger 920, the upstream end of the solvent is a first end 920a, and the downstream end of the solvent is a second end 920b. A refrigerant supply path 980 for introducing the refrigerant liquid Cl is connected at the first end 920a, and a refrigerant discharge path 960 for discharging the refrigerant gas Cg is connected at the second end 920b. Further, a cold water discharge path 970 for discharging the cold water Wo is connected at the first end 920a, and a cold water supply path 950 for introducing the cold water Wi is connected at the second end 920b.

  The counter flow type plate heat exchanger 920 includes a plurality of plates 921. The plurality of plates 921 are made of a heat conductive material and can exchange heat between both surfaces of the plates. A plurality of laminated flow paths are formed inside the plate heat exchanger 920 by arranging the plurality of plates 921 so as to be spaced apart from each other. Further, the refrigerant and the cold water are alternately caused to flow through the plurality of stacked flow paths so that the refrigerant and the cold water flow in directions opposite to each other.

  The plurality of plates 921 are composed of plates 921a, 921b, 921c, 921d, and 921e in this order, and are stacked and spaced from each other. Therefore, a channel 922ab, a channel 922bc, a channel 922cd, and a channel 922de are formed between the stacked plates. As shown in FIG. 2, the refrigerant flows through the flow path 922ab and the flow path 922cd from the refrigerant supply path 980 toward the refrigerant discharge path 960, and the flow path 922bc from the cold water supply path 950 toward the cold water discharge path 970. Cold water flows through the flow path 922de. The refrigerant and the cold water flowing into the plate heat exchanger 920 exchange heat with each other via plates 921b, 921c, and 921d that are heat conductive materials.

A description will be added regarding heat exchange between the refrigerant and the cold water.
The refrigerant is supplied to the first end 920a in the state of a saturated liquid (liquid just before evaporation). The supplied refrigerant proceeds with heat exchange with cold water in the direction fc (the reverse direction of the X axis in FIG. 2) in which the refrigerant flows. As the heat exchange proceeds, the refrigerant evaporates, and the ratio of the refrigerant gas contained in the refrigerant increases.

  The ratio of the gas-phase refrigerant (refrigerant gas) to the entire flowing refrigerant is called quality χ and is expressed by the following equation (1).

χ = Gg / (Gg + Gl) = Gg / G (1)

  Here, G is the mass flow rate of the entire flowing refrigerant, Gg is the mass flow rate of the gas phase refrigerant in the entire refrigerant, and Gl is the mass flow rate of the liquid phase refrigerant (refrigerant liquid) in the entire refrigerant. As the refrigerant evaporates, the mass flow rate Gg of the gas phase refrigerant out of the mass flow rate G of the entire refrigerant increases, so the quality χ increases and approaches 1.

FIG. 3 shows the heat transfer coefficient h ([W / K · m ² ) between each position in the plate heat exchanger 920 in the direction parallel to the refrigerant flow direction fc (X-axis direction) and the cold water. ]). The refrigerant in the plate heat exchanger 920 evaporates from the first end 920a toward the second end 920b. As the evaporation proceeds, the ratio of the refrigerant in the gas phase to the total flowing refrigerant increases, so that the quality χ of the refrigerant increases.

  Therefore, in the plate heat exchanger 920, the refrigerant quality χ is distributed so as to increase from the first end 920a toward the second end 920b (in the direction opposite to the X axis), and at the second end 920b. The highest.

  On the other hand, in the plate heat exchanger 920, the heat transfer coefficient h increases from the first end 920a toward the center of the plate heat exchanger 920, and shows a peak near the center of the plate heat exchanger 920. Further, the heat transfer coefficient h decreases extremely from the center of the plate heat exchanger 920 toward the second end 920b, and then gradually decreases toward a constant value. Here, the position of the peak in the X-axis direction varies depending on the flow speed of the refrigerant, the temperature of the refrigerant, and the type (water, oil, etc.) of the refrigerant.

  At this time, in the plate heat exchanger 920, the region from the center of the plate heat exchanger 920 where the heat transfer coefficient h shows a peak to the first end 920a is the low quality region QL, and the heat transfer coefficient h shows a peak. A region from the center of the plate heat exchanger 920 to the second end 920b is defined as a high quality region QH.

  In the high quality region QH, the refrigerant evaporates further toward the refrigerant flow direction fc, and the refrigerant changes to a spray flow state (a state where droplets are dispersed in the gas phase). When the refrigerant becomes a spray flow, the number of refrigerant droplets in the space is reduced, so that the heat transfer area is reduced, or the area of the refrigerant droplets in contact with the wall surface of the plate is reduced. Is extremely reduced. As a result, in the high quality region QH, the heat transfer coefficient h of the refrigerant extremely decreases toward the refrigerant flow direction fc. FIG. 3 shows an inflection point Pi of the heat transfer coefficient curve of the plate heat exchanger 920. The heat transfer coefficient h decreases extremely before and after the inflection point Pi. If the distance from the first end 920a to the second end 920b is Lf, the distance from the first end 920a to around the inflection point Pi is Ls.

  Further, in the low quality region QL, the evaporation of the refrigerant proceeds to the extent that the spray flow is not reached, and the volume flow rate of the refrigerant increases, so the heat transfer coefficient h of the refrigerant increases. As a result, as shown in the graph of FIG. 3, in the low quality region QL, the heat transfer coefficient h of the refrigerant gradually increases in the refrigerant flow direction fc.

  In particular, a region where the heat transfer coefficient h of the high quality region QH is extremely low is inferior in heat exchange efficiency compared to other regions. As a result, an excessive heat transfer area is required for the plate heat exchanger 920, and the size of the plate heat exchanger 920 is increased.

  Therefore, by adopting the configuration of the heat exchange system 10 of the present embodiment shown in FIG. 4 below, heat exchange over an excessive heat transfer area of the plate heat exchanger 920 is not necessary, and the X of the plate heat exchanger 920 is eliminated. The axial length can be shortened.

  The structure of the heat exchange system 10 of this embodiment is demonstrated.

  As shown in FIG. 4, the heat exchange system 10 of this embodiment includes a heat exchanger 20 including a first heat exchanger 100 and a second heat exchanger 300. In the A region, the first heat exchanger 100 is provided, and in the B region, the second heat exchanger 300 is provided.

  Further, the heat exchange system 10 includes a refrigerant supply unit 80 that supplies refrigerant to the refrigerant flow path of the first heat exchanger 100, a cold water supply unit 90 that supplies cold water to the cold water flow path of the first heat exchanger 100, and a refrigerant flow. A gas-liquid separator 30 is provided that separates the gas phase from the refrigerant that has passed through the passage.

  Furthermore, the heat exchange system 10 includes a cold water outlet 70, a first cold water discharge path 170 and a second cold water discharge path 370, a pump 400, a first refrigerant discharge path 210, a second refrigerant discharge path 220, and a refrigerant outlet 60.

  The structure of the first heat exchanger 100 will be described.

  In the present embodiment, the first heat exchanger 100 is a plate heat exchanger including a plurality of plates 121 stacked at equal intervals. Therefore, since the plate type heat exchanger of this embodiment is configured so that the intervals between the plurality of plates are equal, the assembly process of the plate type heat exchanger is made common, thus simplifying the manufacturing process. In addition, production costs can be reduced. The plurality of plates 121 are made of a heat conductive material and can exchange heat between both surfaces of the plates.

  Furthermore, similarly to the counter-flow plate heat exchanger 920 described with reference to FIG. 2, the first heat exchanger 100 includes a plurality of flow paths stacked inside. In the heat exchange system 10, the refrigerant and the cold water are caused to flow in opposite directions with respect to the plurality of flow paths formed in a stacked manner in the first heat exchanger 100. Furthermore, the heat exchanging system 10 alternately flows the refrigerant, the cold water, and the laminating direction with respect to the plurality of the laminated flow paths in the first heat exchanger 100. Accordingly, the refrigerant liquid Cl and the cold water Wi are alternately flowed in the first heat exchanger 100 in the stacking direction and in the opposite direction, so that the first heat exchanger 100 is a counterflow type. It constitutes a plate heat exchanger.

  The length of the first heat exchanger 100 will be described.

  As will be described below, the heat exchange system 10 according to the present embodiment performs gas-liquid separation between the first heat exchanger 100 and the second heat exchanger 300 to thereby generate the refrigerant gas Cg (gas phase component). While discharging, heat exchange is performed. Since heat exchange is performed while discharging the refrigerant gas Cg, the first heat exchanger 100 does not need to be sufficiently vaporized. Therefore, it is possible to reduce the portion corresponding to the high quality region QH in the first heat exchanger 100 as shown below.

  That is, when the refrigerant liquid Cl is sufficiently vaporized and discharged as the refrigerant gas Cg with one plate heat exchanger, the required length of the plate heat exchanger is Lf. As shown in FIG. 3, in the high quality region QH, the region where the heat transfer coefficient h is extremely low is inferior in heat exchange efficiency compared to other regions, and can be used effectively from the whole heat exchanger. This is not an area. On the other hand, since the first heat exchanger 100 of the present embodiment discharges the refrigerant Cm in the two-phase flow state, it is not necessary to set the length Lf. Therefore, the 1st heat exchanger 100 of this embodiment can be set as the structure which excluded the part corresponding to the area | region which cannot be utilized effectively among the high quality area | region QH. The number of stacked plates in the plate heat exchanger is N1.

  Therefore, the length of the first heat exchanger 100 of the present embodiment is set to Ls shorter than Lf as shown in FIG. The length Ls of the first heat exchanger 100 is from the X-axis position of the lower end 100a of the first heat exchanger 100 to the X-axis position around the inflection point Pi of the heat transfer coefficient curve of the first heat exchanger 100. Equal to the distance.

  The refrigerant path configuration will be described.

  The refrigerant supply unit 80 includes a refrigerant inlet 40 and a first refrigerant supply path 140.

  The refrigerant liquid Cl to be heat exchanged in the heat exchange system 10 is introduced into the heat exchange system 10. The refrigerant liquid Cl introduced into the heat exchange system 10 is introduced from the refrigerant inlet 40. The upstream end of the first refrigerant supply path 140 is connected to the refrigerant inlet 40. Therefore, the refrigerant liquid Cl (saturated liquid) introduced into the refrigerant inlet 40 is introduced into the first refrigerant supply path 140. The downstream end of the first refrigerant supply path 140 is connected to the first heat exchanger 100 at the lower end 100 a of the first heat exchanger 100. Therefore, the refrigerant liquid Cl is introduced from the refrigerant inlet 40 to the first heat exchanger 100 via the first refrigerant supply path 140. The upstream end of the two-phase flow refrigerant supply path 160 is connected to the first heat exchanger 100 at the upper end 100 b of the first heat exchanger 100. Therefore, the first heat exchanger 100 discharges the refrigerant Cm in the two-phase flow state to the two-phase flow refrigerant supply path 160.

  The path configuration of the cold water will be described.

  The cold water supply unit 90 includes a cold water inlet 50, a first cold water supply path 150, and a second cold water supply path 350.

Cold water Wi to be heat exchanged is introduced into the heat exchange system 10. The cold water Wi introduced into the heat exchange system 10 is introduced from the cold water inlet 50. The upstream end of the first cold water supply path 150 is connected to the cold water inlet 50. Therefore, the cold water Wi introduced into the cold water inlet 50 is introduced into the first cold water supply path 150. The upstream end of the second cold water supply channel 350 is connected to the cold water inlet 50. Therefore, the cold water Wi introduced into the cold water inlet 50 is introduced into the second cold water supply channel 350.
As shown in FIG. 4, the cold water inlet 50 is branched and connected to the upstream end of the first cold water supply path 150 and the upstream end of the second cold water supply path 350.

  The downstream end of the first cold water supply path 150 is branched and connected to the first heat exchanger 100 at the upper end 100 b of the first heat exchanger 100. Accordingly, the cold water Wi is introduced from the cold water inlet 50 to the first heat exchanger 100 via the first cold water supply path 150. The upstream end of the first cold water discharge path 170 is branched and connected to the first heat exchanger 100 at the lower end 100 a of the first heat exchanger 100. Therefore, the cold water Wo is discharged from the first heat exchanger 100 via the first cold water discharge path 170.

  The second cold water supply path 350 is branched to a plurality of downstream ends on the downstream side. Each downstream end of the branched second cold water supply path 350 is connected in parallel to the upstream end of each heat transfer tube 310 of the second heat exchanger 300. Therefore, the cold water Wi introduced into the second cold water supply channel 350 is introduced into each heat transfer tube 310 of the second heat exchanger 300.

The second cold water discharge path 370 is branched to a plurality of downstream ends on the downstream side. Each downstream end of the branched second cold water discharge path 370 is branched and connected in parallel to the downstream end of each heat transfer tube 310 of the second heat exchanger 300. Therefore, the cold water Wo discharged from each heat transfer tube 310 of the second heat exchanger 300 is merged through the second cold water discharge path 370 and discharged.
Accordingly, the plurality of heat transfer tubes 310 are connected in parallel to the cold water inlet 50 and the cold water outlet 70.

  The cold water outlet 70 is branched and connected to the downstream end of the first cold water discharge path 170 and the downstream end of the second cold water discharge path 370. Therefore, the cold water Wo discharged from the first heat exchanger 100 and the second heat exchanger 300 is merged via the first cold water discharge path 170 and the second cold water discharge path 370 and discharged to the cold water outlet 70.

  Therefore, as shown in FIG. 4, the cold water introduced into the heat exchange system 10 is branched from the cold water inlet 50 to the first cold water supply path 150 and the second cold water supply path 350, and the first cold water discharge path 170 and the By passing through the two cold water discharge paths 370, the cold water is circulated in parallel to the first heat exchanger 100 and the second heat exchanger 300.

Here, in the refrigerant and cold water paths, the refrigerant liquid Cl and the cold water Wi are supplied to the first heat exchanger 100, converted from the first heat exchanger 100 into the refrigerant Cm and the cold water Wo in a two-phase flow state, and discharged. Explain why.
The refrigerant liquid Cl and the cold water Wi introduced into the first heat exchanger 100 exchange heat with each other by flowing alternately in the first heat exchanger 100 in the stacking direction and in the opposite direction. . The refrigerant liquid Cl subjected to heat exchange absorbs heat of the cold water Wi (heated by the cold water Wi), is converted into a refrigerant Cm in a two-phase flow state, and is discharged from the first heat exchanger 100. The heat-exchanged cold water Wi releases heat to the refrigerant liquid Cl (cooled to the refrigerant liquid Cl) to become cold water Wo and is discharged from the first heat exchanger 100.

The reason why the refrigerant liquid Cl and the cold water Wi are supplied to the second heat exchanger 300, converted into the refrigerant gas Cg and the cold water Wo from the second heat exchanger 300, and discharged will be described.
The refrigerant liquid Cl and the cold water Wi introduced into the second heat exchanger 300 exchange heat with each other inside the second heat exchanger 300. The heat-exchanged refrigerant liquid Cl absorbs the heat of the cold water Wi (heated by the cold water Wi), is converted into the refrigerant gas Cg, and is discharged from the second heat exchanger 300. The heat-exchanged cold water Wi releases heat to the refrigerant liquid Cl (cooled to the refrigerant liquid Cl) to become cold water Wo, and is discharged from the second heat exchanger 300.

  The configuration of the gas-liquid separator 30 and its surroundings will be described.

  The gas-liquid separator 30 is provided between the downstream end of the two-phase flow refrigerant supply path 160 and the upstream end of the second refrigerant supply path 240. The second refrigerant supply path 240 is branched to a plurality of downstream ends on the downstream side. Each downstream end of the branched second refrigerant supply path 240 is connected to a plurality of sprays 320a of a liquid phase introduction unit 320 described below.

Therefore, the gas-liquid separation unit 30 converts the refrigerant Cm in a two-phase flow state (consisting of a gas-liquid phase) discharged from the first heat exchanger 100 to the two-phase flow refrigerant supply path 160 into a refrigerant gas Cg (gas phase component). ) And refrigerant liquid Cl (liquid phase component).
The refrigerant liquid Cl separated by the gas-liquid separation unit 30 is introduced into the second heat exchanger 300 via the second refrigerant supply path 240 and the liquid phase introduction unit 320.
Further, the refrigerant gas Cg separated by the gas-liquid separation unit 30 is discharged to the refrigerant outlet 60 via the first refrigerant discharge path 210 connected to the refrigerant outlet 60.

  Therefore, the heat exchange system 10 of this embodiment performs gas-liquid separation between the first heat exchanger 100 and the second heat exchanger 300, and performs heat exchange while discharging the refrigerant gas Cg (gas phase component). Is going.

  The second heat exchanger 300 and the surrounding structure will be described.

  The second heat exchanger 300 has a hollow space Ss, and has a sealed structure so that the refrigerant gas Cg evaporated by heat exchange can be held in the space Ss.

  The upstream end of the second refrigerant discharge path 220 is connected to the second heat exchanger 300 so as to circulate with the space Ss, and the downstream end of the second refrigerant discharge path 220 is connected to the refrigerant outlet 60. Therefore, the refrigerant gas Cg held in the space Ss of the second heat exchanger 300 is discharged to the refrigerant outlet 60 via the second refrigerant discharge path 220.

  The second heat exchanger 300 includes a plurality of flow paths formed by a plurality of heat transfer tubes 310 in the space Ss. The cold water Wi supplied to the second heat exchanger 300 is caused to flow into the heat transfer tube 310. In addition, the second heat exchanger 300 includes a liquid phase introduction unit 320 at the upper side, and supplies the refrigerant liquid Cl to the outer peripheral surfaces of the plurality of heat transfer tubes 310.

  In the present embodiment, the liquid phase component introduction unit 320 includes a plurality of sprays 320a as a spraying unit. Each spray 320 a spreads the refrigerant liquid Cl toward the plurality of heat transfer tubes 310 inside the second heat exchanger 300. The sprayed refrigerant liquid Cl contacts the outer peripheral surfaces of the plurality of heat transfer tubes 310.

  The plurality of heat transfer tubes 310 are made of a heat conductive material and can exchange heat between the outer peripheral surface of the heat transfer tubes 310 and the heat transfer tubes 310. Therefore, by bringing the dispersed refrigerant liquid Cl into contact with the outer peripheral surfaces of the plurality of heat transfer tubes 310, the second heat exchanger 300 is caused to flow in the refrigerant liquid Cl supplied to the surface of the heat transfer tubes 310 and the heat transfer tubes 310. Heat exchange is performed with the cold water Wi.

  As shown in FIGS. 4 and 6, each heat transfer tube 310 is arranged such that the tube axis extends in the Y-axis direction (horizontal direction). The plurality of heat transfer tubes 310 are arranged in a lattice form in the vertical and horizontal directions (X-axis direction and Z-axis direction) in the XZ plan view. In this embodiment, as shown in FIGS. 4 and 6, a total of 21 heat transfer tubes 310 are arranged in a grid, with seven stages in the vertical direction and three rows in the horizontal direction.

  The structure of the pump 400 and its surroundings will be described.

  The pump 400 is installed below the second heat exchanger 300.

  The upstream of the pump 400 is connected to the downstream end of the pump supply flow path 401, and the downstream of the pump 400 is connected to the upstream end of the pump discharge flow path 402. The upstream end of the pump supply channel 401 is connected to the lower part of the second heat exchanger 300 so as to circulate with the space Ss. As shown in FIG. 4, the downstream end of the pump discharge flow path 402 is connected to the second refrigerant supply path 240 on the upstream side of the branch point on the downstream side of the second refrigerant supply path 240.

  Therefore, the pump 400 lifts the refrigerant liquid Cl accumulated in the lower part of the second heat exchanger via the pump supply channel 401 and the pump discharge channel 402 and supplies it to the second refrigerant supply channel 240. The refrigerant liquid Cl supplied to the second refrigerant supply path 240 is reintroduced into the second heat exchanger 300 through the liquid phase introduction unit 320. Accordingly, the pumped refrigerant liquid Cl is supplied again to the second refrigerant supply path 240 and thereby comes into contact with the plurality of heat transfer tubes 310 again.

  The operation of the second heat exchanger 300 will be described.

  The refrigerant liquid Cl introduced into the liquid phase component introducing unit 320 via the second refrigerant supply path 240 is dispersed toward the plurality of heat transfer tubes 310 by the plurality of sprays 320a. The plurality of sprays 320a spray the refrigerant liquid Cl toward the outer peripheral surface of the uppermost three heat transfer tubes 310a among the plurality of heat transfer tubes 310.

  The refrigerant liquid Cl sprayed on the heat transfer tube 310a flows down to the lower heat transfer tube 310b while traveling along the outer peripheral surface of the heat transfer tube 310a. The refrigerant liquid Cl that has flowed down to the lower heat transfer tube 310b flows down to the next lower heat transfer tube while traveling along the outer peripheral surface of the heat transfer tube 310b.

  By spraying sufficient refrigerant liquid Cl to the heat transfer pipe 310, the refrigerant liquid Cl flows down from the uppermost stage to the lowermost heat transfer pipe 310 without interruption. The refrigerant liquid Cl that flows down without interruption becomes a liquid film Cst having a surface (XY plane) that extends in the vertical direction and the tube axis direction of the heat transfer tube 310. The liquid film Cst is formed in each row of the heat transfer tubes 310. In the present embodiment, three liquid films Cst are formed corresponding to the three rows of heat transfer tubes 310.

  By sufficiently spraying the refrigerant liquid Cl so that the liquid film Cst is formed, the refrigerant liquid Cl contacts almost the entire outer circumference of the heat transfer tube 310. If the refrigerant liquid Cl is brought into contact with substantially the entire outer periphery of the heat transfer tube 310, heat exchange can be performed on almost the entire outer periphery of the heat transfer tube 310, thereby enabling highly efficient heat exchange.

  A part of the refrigerant liquid Cl that travels on the outer peripheral surface of each heat transfer tube 310 is evaporated and vaporized by heat exchange to become refrigerant gas Cg. The vaporized refrigerant gas Cg is discharged to the refrigerant outlet 60 via the second refrigerant discharge path 220 while being held in the space Ss.

  Therefore, the second heat exchanger 300 acts as a liquid film heat exchanger.

  The refrigerant liquid Cl is sprayed as much as it flows from the lowermost heat transfer tube 310 to the lower part of the second heat exchanger 300. The refrigerant liquid Cl that has flowed down to the lower part of the second heat exchanger 300 is stored in the lower part of the second heat exchanger 300. The stored refrigerant liquid Cl is pumped by the pump 400 and brought into contact with the plurality of heat transfer tubes 310 again.

  Therefore, since the refrigerant liquid Cl that has flowed down to the lower part of the second heat exchanger 300 is reused, the refrigerant liquid Cl can be used effectively.

  As shown in FIG. 4, by appropriately finely adjusting the refrigerant liquid Cl to be dispersed, all of the refrigerant liquid Cl evaporates in the lowermost heat transfer tube 310 so that there is no refrigerant liquid Cl flowing down from the lowermost heat transfer tube 310. You may comprise. In this case, it is not necessary to provide the pump 400.

As described above, in the present embodiment, the length in the X-axis direction of the plate heat exchanger of the first heat exchanger 100 can be shortened. In the present embodiment, only the refrigerant liquid that could not be vaporized by the first heat exchanger 100 is vaporized by the second heat exchanger 300, so the number of heat transfer tubes 310 can be reduced, The scale of the two heat exchanger 300 can also be reduced. As the scale increases, the number of heat transfer tubes 310 increases and costs increase. For such a heat transfer tube heat exchanger, it is effective to reduce the scale of the second heat exchanger 300.
Therefore, in the present embodiment, by combining the first heat exchanger 100 and the second heat exchanger 300, the length of the first heat exchanger 100 in the X-axis direction can be shortened, and the second heat exchange is performed. The scale of the vessel 300 can be reduced.

  Furthermore, in the present embodiment, the refrigerant liquid Cl obtained by separating the refrigerant gas Cg from the refrigerant Cm in a two-phase flow state discharged from the first heat exchanger 100, that is, a saturated liquid is used as the refrigerant of the second heat exchanger 300. doing. Therefore, since the refrigerant liquid Cl made of a saturated liquid can be introduced into the second heat exchanger 300, there is also a synergistic effect that efficient heat exchange is possible.

"Second embodiment"
A second embodiment of the heat exchange system according to the present invention will be described with reference to FIG.

  The structure of the heat exchange system 10 'of this embodiment is basically the same as that of the first embodiment, but differs in that a liquid film heat exchanger and a full liquid heat exchanger are used in combination. Other configurations are the same as those in the first embodiment.

  As shown in FIG. 7, the second heat exchanger 300 ′ of the heat exchange system 10 ′ of the present embodiment includes a liquid film heat exchanger 301 ′ and a full liquid heat exchanger 302 ′. In the area B of the second heat exchanger 300 ′, a liquid film heat exchanger 301 ′ is provided, and in the area C of the second heat exchanger 300 ′, a full liquid heat exchanger 302 ′ is provided.

  The liquid film heat exchanger 301 ′ forms a liquid film Cst in each row of the heat transfer tubes 310 in the B region as in the first embodiment.

  The full liquid heat exchanger 302 ′ includes a refrigerant reservoir 302 a ′ in which at least four side surfaces (XY side surface and ZX side surface) and a lower surface are closed. The refrigerant reservoir 302a ′ has a C region in which the four side surfaces and the lower surface are closed, and is configured so that the refrigerant liquid Cl can be accumulated in the C region. In the region C, a part of the plurality of heat transfer tubes 310 is provided, and in the case of this embodiment, a total of 12 heat transfer tubes 310 are provided, four stages in the vertical direction and three levels in the horizontal direction.

  The refrigerant liquid Cl that has flowed down from the liquid film Cst accumulates in the C region of the full liquid heat exchanger 302 ′. When the heat transfer tube 310 in the C region is immersed in the accumulated refrigerant liquid Cl, the accumulated refrigerant liquid Cl comes into contact with the outer peripheral surface of the heat transfer tube 310 in the C region. Therefore, heat exchange is performed between the refrigerant liquid Cl in contact with the surface of the heat transfer tube 310 in the region C and the cold water Wi flowing in the heat transfer tube 310.

  In the present embodiment, a heat exchange system in which a liquid heat exchanger and a full liquid heat exchanger are combined with a plate heat exchanger can be configured, and a heat exchange system in accordance with an optimum area, volume, and scale. Can be provided.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to the said embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

In the present embodiment, the plurality of plates 121 of the first heat exchanger 100 are stacked at equal intervals. However, when it is not important to standardize assembly parts and simplify the manufacturing process, the plates 121 may not be equal intervals. I do not care.
Moreover, about the some plate 121 of the 1st heat exchanger 100, the space | interval of the plate of a cold water flow path and the space | interval of the plate of a refrigerant | coolant flow path may each differ.

  In this embodiment, cold water is supplied in parallel from the same cold water inlet 50 to the first heat exchanger and the second heat exchanger, but the first heat exchanger 100 and the second heat exchanger, You may supply cold water separately from a different cold water source.

  One spray 320a may be disposed in each heat transfer tube 310. Further, a plurality of sprays 320a arranged in each heat transfer tube 310 may be arranged in the tube axis direction. If a plurality are arranged in the tube axis direction, the outer peripheral surface of the heat transfer tube 310 can be used effectively.

  In the present embodiment, the refrigerant liquid Cl is sprayed on the heat transfer tubes by the plurality of sprays 320a. It may be sprayed. Furthermore, if the refrigerant liquid Cl can be supplied evenly to the surface of the heat transfer tube, the refrigerant liquid Cl can be supplied to the surface of the heat transfer tube by dropping droplets of the refrigerant liquid Cl from the end of the pipe or the opening on the side of the pipe. Good.

  In 2nd embodiment, although 2nd heat exchanger 300 'provided with liquid film type heat exchanger 301' and full liquid type heat exchanger 302 'was used, the structure which immerses all the heat exchanger tubes in refrigerant | coolant liquid Cl. By doing so, the second heat exchanger may be configured only by the full liquid heat exchanger.

  In the embodiment, as shown in FIGS. 4 and 7, each refrigerant introduction path, refrigerant discharge path, cold water introduction path, and branch connection of the cold water discharge path and each heat exchanger are external to each plate heat exchanger. Although it branches and connects, it may connect without branching outside each plate type heat exchanger, and may branch inside each heat exchanger.

  In the present embodiment, the plurality of heat transfer tubes 310 are arranged in seven rows vertically and three rows horizontally, for a total of 21 tubes, but any number may be arranged vertically and horizontally.

  Each heat transfer tube 310 is arranged with the tube axis facing in the Y-axis direction, but may be in any direction as long as it is along the YZ plane, for example, with the tube axis facing in the Z-axis direction. Good. In this case, the outer peripheral surfaces of the plurality of heat transfer tubes can be effectively used when the plurality of heat transfer tubes are arranged in a grid pattern on the top and bottom and the left and right in the XY plan view.

  In this embodiment, the length of the first heat exchanger 100 is set to Ls corresponding to the X position before and after the inflection point Pi of the heat transfer coefficient curve of the plate heat exchanger, but at least the plate heat exchanger Any length from the X position of the lower end 100a of the heat transfer coefficient may be used as long as it exceeds the X position of the peak of the heat transfer coefficient curve. As the length of the first heat exchanger 100 is shortened, an excessive heat transfer area of the first heat exchanger 100 can be reduced, and as the length of the first heat exchanger 100 is increased, The number of stacked first heat exchangers 100 can be reduced. Further, the longer the length of the first heat exchanger 100, the more the burden of heat conversion in the second heat exchanger 300 can be reduced.

  Any material such as aluminum, graphite, copper, ceramics or the like may be used as the heat conductive material used in the plate of the first heat exchanger and the heat transfer tube of the second heat exchanger of the present embodiment.

  As the refrigerant of this embodiment, any refrigerant such as ammonia or HFC may be used.

  The present embodiment is an apparatus that cools cold water, but may be applied to an apparatus that cools room temperature water, hot water, or the like, or may be applied to an apparatus that cools oil.

  Various components such as a gravity separation method, a centrifugal separation method, and a filter method can be used as the gas-liquid separation unit.

  The plate-type heat exchanger used in the first heat exchanger is not limited to the opposed type, and may be an orthogonal type in which a refrigerant channel through which a refrigerant flows and a cold water channel through which cold water flows are arranged orthogonally. Further, the crossing is not limited to the orthogonal arrangement, and any angle may be used as long as the refrigerant flow path through which the refrigerant flows and the cold water flow path through which the cold water flows intersect.

  The plate heat exchanger used in the first heat exchanger may be a plate fin heat exchanger having a heat transfer promoting effect on the plate surface by using plate fins on the plate. By using a plate fin heat exchanger, it is possible to improve heat transfer performance and to reduce the size of the heat exchanger.

  The heat transfer tube used in the second heat exchanger may employ a heat transfer tube having a heat transfer promotion structure on the inner surface, the outer surface, or the inner and outer surfaces. By adopting a heat transfer tube having a heat transfer promoting structure, it is possible to improve heat transfer performance and reduce the size of the heat exchanger.

10: Heat exchange system 20: Heat exchanger 30: Gas-liquid separator 40: Refrigerant inlet 50: Cold water inlet 60: Refrigerant outlet 70: Cold water outlet 80: Refrigerant supply part 90: Cold water supply part 100: First heat exchanger 100a : Lower end 100b: upper end 121: plural plates 140: first refrigerant supply path 150: first cold water supply path 160: two-phase flow refrigerant supply path 170: first cold water discharge path 210: first refrigerant discharge path 220: second Refrigerant discharge path 240: second refrigerant supply path 300: second heat exchanger 300 ': second heat exchanger 301: liquid film heat exchanger 301': liquid film heat exchanger 302 ': full liquid heat exchange Unit 302a ': Refrigerant reservoir 310: Heat transfer tube 310a: Heat transfer tube 310b: Heat transfer tube 320: Liquid phase introduction unit 320a: Spray 350: Second cold water supply channel 370: Second cold water discharge channel 400: Pump 401: Pump supply Flow path 402 Pump discharge flow path 920: plate heat exchanger 920a: first end 920b: second end 921: a plurality of plates 921a: plate 921b: plate 921c: plate 921d: plate 921e: plate 922ab: flow path 922bc: flow path 922cd : Channel 922de: Channel 950: Chilled water supply path 960: Refrigerant discharge path 970: Chilled water discharge path 980: Refrigerant supply path Cg: Refrigerant gas Cl: Refrigerant liquid Cm: Two-phase flow state refrigerant Cst: Liquid film fc: Refrigerant Flow direction h: Heat transfer coefficient Pi: Inflection point QH: High quality region QL: Low quality region Ss: Space Wi: Cold water Wo: Cold water

Claims (7)

A first heat exchanger having a plurality of plates stacked and spaced apart from each other, wherein the plurality of plates alternately form a refrigerant flow path through which refrigerant flows and a cold water flow path through which cold water flows; ,
A refrigerant supply unit for supplying the refrigerant to the refrigerant flow path of the first heat exchanger;
A cold water supply unit for supplying the cold water to the cold water flow path of the first heat exchanger;
A gas-liquid separation unit for separating a gas phase component from the refrigerant that has passed through the refrigerant flow path;
And a second heat exchanger having a heat transfer tube with which the liquid phase of the refrigerant that has passed through the gas-liquid separation unit comes into contact. A two-phase flow refrigerant supply unit that is disposed above the first heat exchanger and distributes the refrigerant that has passed through the refrigerant flow path from the first heat exchanger to the gas-liquid separation unit;
The heat exchange system according to claim 1, further comprising a liquid phase supply unit that is disposed above the second heat exchanger and supplies the liquid phase of the refrigerant to the second heat exchanger. The heat exchange system according to claim 1, further comprising a spraying unit that sprays the liquid phase component from above the heat transfer tube. The heat exchange system according to any one of claims 1 to 3, wherein each of the heat transfer tubes includes a plurality of heat transfer tubes arranged in a horizontal direction and arranged vertically. The heat exchange system according to any one of claims 1 to 4, wherein the cold water supply unit supplies the cold water to the heat transfer pipe of the second heat exchanger in parallel with the first heat exchanger. . Further comprising a pump below the second heat exchanger;
The heat exchange system according to any one of claims 1 to 5, wherein a liquid phase component of the refrigerant accumulated in a lower portion of the second heat exchanger is pumped by the pump and brought into contact with the heat transfer tube. The second heat exchanger further includes a refrigerant reservoir that stores a liquid phase component of the refrigerant in a lower portion thereof,
The heat exchange system according to any one of claims 1 to 5, wherein at least a part of the heat transfer tube is disposed inside the refrigerant reservoir.

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