JP2019020068A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress uneven flow between a plurality of flow paths and maintain high heat transfer performance in a heat exchanger for heat exchange of gas-liquid two-phase flow. A heat exchanger according to one embodiment includes a plurality of first plates forming a plurality of first flow paths through which a first fluid flows and a plurality of second plates forming a plurality of second flow paths through which a second fluid flows. A second plate and a plate structure including a plurality of stacked plates including the second plate, and the first fluid is in a gas-liquid two-phase state in at least a part of the first flow path. A first inlet header space communicating with the fluid supply part and the plurality of first flow paths formed in each of the plurality of first plates; a discharge part of the first fluid; and the plurality of first plates A first outlet header space communicating with each of the plurality of first flow paths formed therein is formed in the plurality of first plates, and each of the plurality of first flow paths has a corrugated flow path shape. And the upstream side region formed at the downstream side of the upstream side region, and the flow path shape is linear. Having a downstream region formed on. [Selection diagram] Fig. 6

Description

  The present disclosure relates to a heat exchanger in which one of the heat exchange fluids is a gas-liquid two-phase fluid.

The NH ₃ is used as the primary refrigerant, _NH 3 / CO ₂ refrigeration using CO ₂ as a secondary refrigerant is vaporized and NH ₃ in the gas-liquid two-phase, thereby the heat exchanger for liquefying the CO ₂ vapor (CO ₂ A liquefier). Conventionally, shell-and-plate heat exchangers, plate-type heat exchangers, shell-and-tube heat exchangers, and the like are used for this type of liquefier.
In Patent Document 1, NH ₃ is used as a primary refrigerant, CO ₂ is used as a secondary refrigerant, and these flow paths are constituted by a large number of fine flow paths called so-called microchannels, whereby heat transfer between both media is performed. A heat exchanger aimed at improving performance is disclosed.

JP 2015-1114080 A

The gas-liquid two-phase flow that flows in the pipe generally increases the heat transfer rate because the liquid film thickness decreases as the vapor ratio increases. Once in the state, the heat transfer coefficient decreases rapidly. In addition, in boiling due to liquid heating, the heat capacity of the heat exchanger consisting of a large number of flow paths branching in parallel is likely to cause backflow in some flow paths. As a result, the heat exchange efficiency decreases.
Moreover, in a heat exchanger in which a gas-liquid two-phase fluid is divided into a plurality of flow paths, such as the heat exchanger disclosed in Patent Document 1, generally, a flow path with a small liquid ratio has a heat transfer performance. Is greatly reduced. Therefore, in order to increase the heat transfer coefficient, it is possible to suppress uneven flow between multiple flow paths and to make the flow rate (mass velocity) and quality (dryness) of gas-liquid two-phase flow uniform so that the heat transfer as a whole. It is important to improve performance.
Incidentally, in particular drift tends to occur when the gas-liquid density ratio is high NH ₃ is a gas-liquid two-phase flow.

  In an embodiment, in view of the above problems, in a heat exchanger that performs heat exchange by diverting a gas-liquid two-phase fluid to a plurality of flow paths, uneven flow between the plurality of flow paths is suppressed and heat transfer performance is maintained high. For the purpose.

(1) A heat exchanger according to an embodiment
A heat exchanger for exchanging heat between the first fluid and the second fluid to vaporize the first fluid,
A plurality of stacked layers including a plurality of first plates forming a plurality of first flow paths through which the first fluid flows, and a plurality of second plates forming a plurality of second flow paths through which the second fluid flows. Comprising a plate structure composed of
The first fluid is in a gas-liquid two-phase state in at least a part of the first flow path;
A first inlet header space communicating with the first fluid supply section and the plurality of first flow paths formed in each of the plurality of first plates; the first fluid discharge section; A first outlet header space communicating with the plurality of first flow paths formed in each of the one plate is formed in the plurality of first plates;
Each of the plurality of first flow paths includes an upstream area in which the flow path shape is formed in a waveform, and a downstream area in which the flow path shape is formed in a straight line and located downstream of the upstream area, Have

According to the configuration of (1) above, the plurality of first flow paths are each formed in a corrugated shape in the upstream region, and the low-quality first fluid flowing in the corrugated flow path forms a turbulent flow. Therefore, heat transfer with the second fluid is promoted. Moreover, since pressure loss increases by forming a turbulent flow, generation | occurrence | production of a backflow can be suppressed and the fall of a process flow rate can be suppressed by this. Furthermore, since the pressure loss increases, the variation in the pressure loss between the first flow paths is relatively relaxed, so that the drift between the plurality of first flow paths is suppressed. Thereby, the flow path with a small liquid ratio can be eliminated, and the heat transfer performance as a whole can be maintained high.
In addition, a waveform shape means the shape meandering alternately in the direction orthogonal to a flow direction.

  In addition, since the plurality of first flow paths each have a linear flow path shape in the downstream region, the high-quality first fluid flowing through the linear flow path has a reduced pressure loss and air bubbles. It becomes easy to move downstream, and backflow is suppressed. Further, in the downstream region where the liquid content is reduced by evaporation, the corrugated flow path causes the liquid film formed on the heat transfer wall to be divided, and a dryout in which the heat transfer rate is reduced is likely to occur. By forming the flow path shape of the downstream region in a straight line, the formation of dryout can be delayed. Thereby, the heat transfer performance of the first fluid can be maintained high even in the downstream region.

(2) In one embodiment, in the configuration of (1),
Each of the plurality of first flow paths is provided with a throttle portion at the inlet.
According to the configuration of (2) above, each of the plurality of first flow paths is provided with a throttle portion having a reduced cross-sectional area at the inlet portion, and by increasing the pressure loss at the throttle portion, the vaporized first fluid A backflow can be suppressed, and thereby a decrease in the treatment flow rate can be suppressed.

(3) In one embodiment, in the configuration of (2),
In the throttle portion, each of the plurality of first flow paths is formed in a wave shape.
According to the configuration of (3) above, the flow path shape of the first flow path is formed in a corrugated shape at the throttle portion formed at the inlet of the first fluid, thereby increasing the pressure loss of the first flow path, The aperture effect can be improved.

(4) In one embodiment, in any one of the configurations (1) to (3),
Each inlet of each of the plurality of first flow paths has an angle between a flow direction of the first fluid flowing through the first inlet header space and a flow direction of the first fluid when flowing into the first flow path. Is inclined with respect to a direction orthogonal to the flow direction of the first fluid in the first inlet header space so that the change in the angle is less than 90 °.
According to the configuration of (4) above, since the change in angle when the first fluid flows into the first flow path from the first inlet header space is less than 90 °, the first fluid is removed from the first inlet header space. Pressure loss when flowing into the first flow path can be reduced. Accordingly, a difference in distance from the first fluid supply unit between the plurality of first flow paths does not greatly affect the inflow amount of the first fluid into each first flow path. The drift of the first fluid can be suppressed.

(5) In one embodiment, in any one of the configurations (1) to (4),
The boundary between the upstream region and the downstream region of each of the plurality of first flow paths is in a region where the first fluid forms an annular flow.
“Annular flow” refers to a gas-liquid two-phase flow in which a liquid phase is formed in an annular shape in contact with a wall surface forming a flow path, and a gas phase is formed on the center side of the flow path. The heat transfer coefficient with the second fluid passing through is high.
According to the configuration of (5) above, since the first fluid forms an annular flow having high heat transfer characteristics at the boundary between the upstream region and the downstream region, high heat transfer in the first channel. Performance can be obtained. Further, in the downstream region, the flow-out shape has a straight line shape, so that the dryout can be delayed, whereby the heat exchange efficiency can be kept high.

(6) In one embodiment, in any one of the configurations (1) to (5),
The boundary between the upstream region and the downstream region of each of the plurality of first flow paths is in a region where the quality of the first fluid is 0.3 or more and 0.8 or less.
According to the configuration of (6) above, the boundary between the upstream region and the downstream region of the first flow path is a region where the quality of the first fluid is 0.3 to 0.8, that is, the first fluid is annular. Since it exists in the area | region which has formed the flow, high heat-transfer performance can be maintained between the 1st fluid and the 2nd fluid in the upstream area and the downstream area.

(7) In one embodiment, in any one of the configurations (1) to (6),
The first flow path wall constituting each of the plurality of first flow paths is a second flow path wall constituting each of the corresponding plurality of second flow paths when viewed from the stacking direction of the plate constituents. And at least some areas overlap.
According to the configuration of (7) above, the first flow path wall and the second flow path wall are arranged so as to overlap each other when viewed from the stacking direction of the plate structure, thereby forming the first flow path. In addition, when the first plate and the second plate on which the second flow path is formed are diffusion bonded, a high bonding pressure can be applied to the first flow path wall and the second flow path wall. As a result, the bonding strength between the first plate and the second plate can be increased.

(8) In one embodiment, in any one of the configurations (1) to (7),
Each of the plurality of second flow paths includes a linear flow path disposed along the same direction as the first flow path,
The first flow path wall constituting the upstream region of each of the plurality of first flow paths is the straight line of each of the corresponding second flow paths when viewed from the stacking direction of the plate structure. Are arranged so as to intersect with the second channel wall constituting the channel in a constant pitch (wavelength / 2).

  According to the configuration of (8) above, since the first flow path wall is arranged so as to intersect the second flow path wall at a constant pitch when viewed from the stacking direction of the plate structure, the first flow path The wall and the second flow path wall overlap each other at a constant pitch at a portion where they intersect each other. Accordingly, since a high bonding pressure can be applied to the first flow path wall and the second flow path wall during diffusion bonding, the bonding strength between the first plate and the second plate can be increased.

(9) In one embodiment, in the configuration of (8),
The pitch (wavelength / 2) is 1 mm or more and 3 mm or less.
According to the configuration of (9) above, since the first flow path wall and the second flow path wall overlap with a pitch of 1 to 3 mm, a high bonding pressure is applied to the first flow path wall and the second flow path wall during diffusion bonding. Can be added. As a result, the bonding strength between the first plate and the second plate can be increased.

(10) In one embodiment, in any one of the configurations (1) to (9),
The first outlet header space forms a space penetrating along the stacking direction of the plate structure including the plurality of second plates.
The pressure loss of the first fluid from the first inlet header space to the first outlet header space is the sum of the pressure losses of the respective first fluids in the first inlet header space, the first flow path, and the first outlet header space. .

According to the configuration of (10) above, since the first outlet header space forms a space penetrating along the stacking direction of the plurality of plates, the flow rate of the first outlet header space through which steam flows is reduced. Pressure loss can be reduced. As a result, since the ratio of the pressure loss of the first fluid in the first flow path relatively increases, the difference in pressure loss between the plurality of first flow paths becomes the absolute value of the pressure loss in each first flow path. Compared to a relative reduction.
Further, since the pressure loss in the first outlet header space is reduced, the first fluid is likely to flow into the first outlet header space from the first flow path, so that the pressure loss at the outlet portions of the plurality of first flow paths is reduced. The difference is also reduced.
In this way, the difference in pressure loss between the plurality of first flow paths is reduced, so that the uneven flow between the plurality of first flow paths is suppressed, whereby the heat transfer performance of the entire first flow path can be maintained high. .

(11) In one embodiment, in any one of the configurations (1) to (10),
The first inlet header space is divided by the plurality of second plates along the stacking direction of the plate structure.
According to the configuration of (11) above, the first inlet header space is divided along the plate stacking direction by the plurality of second plates, and therefore the first flowing into the first flow path between the plurality of first plates. The fluid flow rate can be balanced. Thereby, the drift suppression effect between the plurality of first flow paths can be improved.

(12) In one embodiment, in any one of the configurations (1) to (11),
The plurality of first plates and the plurality of second plates are alternately arranged along the stacking direction of the plate structures.
According to the configuration of (12) above, the plurality of first plates and the plurality of second plates are alternately arranged along the plate stacking direction, so that the first flow path is between the plurality of first plates. The volume of the first inlet header space communicating with can be evenly divided. Accordingly, the flow rate of the first fluid flowing into the first flow path can be equalized between the first plates, so that the effect of suppressing the drift between the plurality of first flow paths can be improved. In addition, since the first plate through which the first fluid flows and the second plate through which the second flow channel flows are alternately arranged adjacent to each other in a laminated structure, the heat transfer area of the first fluid and the second fluid can be increased, Thereby, heat transfer performance can be improved.

(13) In one embodiment, in any one of the configurations (1) to (12),
The first inlet header space is configured such that in each of the plurality of first plates, a channel cross-sectional area gradually decreases as the distance between each of the plurality of first channels and the supply unit increases (hereinafter referred to as “the first inlet header space”). This configuration is also called “tapered structure”.)
In the first inlet header space, the first fluid flows in order from the first flow path close to the supply unit to the plurality of first flow paths formed in each first plate. The flow rate decreases as the distance from the supply unit increases.

According to the configuration of (13) above, since the first inlet header space has a tapered structure, the first fluid is distributed to the plurality of first flow paths formed in each first plate, so that the first inlet header space is obtained. Even if the flow rate of the first fluid decreases, it is possible to suppress a decrease in the flow rate of the first fluid in the inlet header space. As a result, the annular flow can be formed in the first inlet header space, and the annular flow is formed in the first inlet header space, so that the uneven flow between the plurality of first flow paths can be suppressed. High heat transfer performance between the first fluid and the second fluid can be maintained in the first flow path.
Further, in a structure in which a plurality of plates are stacked to form a flow path, by adopting a tapered structure, it is possible to easily cope with a large increase or decrease in the number of plates, and a complicated header structure is not obtained. This makes it possible to reliably supply the first fluid that can suppress the drift between the first flow paths.

(14) In one embodiment, in any one of the configurations (1) to (13),
The first fluid supply part and the first fluid discharge part are formed in the plate structure along the stacking direction of the plate structure.
According to the configuration of (14) above, the first fluid supply section and the discharge section are formed in the plate structure, so that the first fluid supply section and the discharge section are used as separate structures on the outside of the plate structure. There is no need to provide it. Furthermore, the piping for connecting the first fluid supply section and the first inlet header space and the piping for connecting the first fluid discharge section and the second outlet header space are not required, so the heat exchanger is made compact. In addition, the cost can be reduced.

(15) In one embodiment, in any one of the configurations (1) to (14),
In each of the plurality of first plates, each of the plurality of first flow paths is arranged in parallel with each other,
In each of the plurality of second plates, the plurality of second flow paths are arranged in parallel to each other.
According to the configuration of (15) above, the plurality of first flow paths and the plurality of second flow paths are arranged in parallel so that the first flow path and the second flow path are close to each other over the entire length of the flow path. Can be placed. Thereby, the heat transfer performance between the first fluid and the second fluid can be improved.
In particular, the effect of suppressing the drift between the plurality of first flow paths can be improved by the combination of the parallel arrangement of the plurality of first flow paths and the tapered structure of the first inlet header space.

(16) In one embodiment, in any one of the configurations (1) to (15),
At least a part of the plurality of first flow paths formed in the first inlet header space and the plurality of first plates is the first fluid flowing through the first inlet header space and the plurality of first flow paths. Are configured to form an annular flow.
According to the configuration of (16) above, in the first inlet header space and each of the first flow paths, the first fluid forms an annular flow in which heat transfer characteristics with the second fluid are enhanced. Heat transfer performance can be improved.

(17) In one embodiment, in any one of the configurations (1) to (16),
The maximum width of the plurality of first flow paths formed on the plurality of first plates and the second flow path formed on the plurality of second plates is 2 mm or less (preferably 0.1 to 1.0 mm). It is.
According to the configuration of (17) above, the first flow path and the second flow path can be formed as fine flow paths having a maximum width of 2 mm or less, so that a large number of first flow paths can be formed in the first plate, and Many second flow paths can be formed in two plates. Thereby, since the heat transfer area of these flow paths can be dramatically increased, the heat transfer performance between the first fluid and the second fluid can be dramatically increased.

(18) In one embodiment, in any one of the configurations (1) to (17),
A second fluid supply section; a second inlet header space communicating with each of the supply section and the plurality of second flow paths; a discharge section for the second fluid; the discharge section; and the plurality of second sections. A second outlet header space communicating with each of the flow paths is formed in the plate structure,
The second inlet header space and the second outlet header space are disposed on both sides of the plurality of first flow paths along a direction intersecting with each of the plurality of first flow paths.
Each of the plurality of second flow paths is
An inlet side region and an outlet side region disposed along a direction intersecting with each of the plurality of first flow paths;
An intermediate region disposed along the same direction as each of the plurality of first flow paths;
including.

According to the configuration of (18) above, the second inlet header space and the second outlet header space of the second flow path are arranged along the direction intersecting the first flow path. The two outlet header spaces can be arranged without interfering with the first inlet header space and the first outlet header space of the first flow path, thereby increasing the degree of freedom of arrangement of the second inlet header space and the second outlet header space. be able to.
In addition, since the intermediate region of the second flow path is arranged along the same direction as the first flow path, the first flow path and the second flow path can be disposed close to each other, so that the first fluid and the second flow path in the intermediate area are Heat transfer performance with two fluids can be improved.
Further, since the inlet side region and the outlet side region of the second flow path are arranged along the direction intersecting with the first flow path, the first flow path wall and the second flow path constituting the first flow path are arranged. It overlaps with the 2nd flow path wall which comprises, with a fixed pitch. Therefore, when the first plate and the second plate are diffusion bonded, a high bonding pressure can be applied to the first flow path wall and the second flow path wall. As a result, the bonding strength between the first plate and the second plate can be increased.

(19) In one embodiment, in any one of the configurations (1) to (18),
The first fluid is NH ₃ and the second fluid is CO ₂ ;
The heat exchanger is a CO ₂ liquefier that heat-exchanges the first fluid and the second fluid to vaporize the first fluid.
According to the above configuration (19), the CO ₂ of the NH ₃ and the gas in the gas-liquid two-phase vaporizes NH ₃ by heat exchange, in CO ₂ liquefaction unit for liquefaction of CO _2, a large gas-liquid density ratio NH ₃ is particularly prone to drift, but even if the first fluid is NH ₃ , it is possible to suppress drift between the plurality of first flow paths, and the dry-out in which heat transfer is reduced in the downstream region of the first flow path. Therefore, the heat transfer performance between NH ₃ and CO ₂ can be maintained high.

  According to one embodiment, in a heat exchanger that performs heat exchange by diverting a gas-liquid two-phase fluid to a plurality of flow paths, heat transfer as a whole heat exchanger is suppressed by suppressing a drift between the plurality of flow paths. High performance can be maintained.

It is a perspective view of the heat exchanger which concerns on one Embodiment. It is a front view of the heat exchanger which concerns on one Embodiment. It is a side view of the heat exchanger which concerns on one Embodiment. It is sectional drawing which follows the AA line in FIG. It is sectional drawing which follows the BB line in FIG. It is a front view which shows the surface of the 1st plate which concerns on one Embodiment. It is a front view which shows the back surface of the 1st plate which concerns on one Embodiment. It is a front view which shows the upstream area | region of the 1st flow path which concerns on one Embodiment. It is sectional drawing which follows the C1C line in FIG. FIG. 7 is a cross-sectional view taken along line D-D in FIG. 6. It is a front view which shows the surface of the 2nd plate which concerns on one Embodiment. It is a front view which shows the back surface of the 2nd plate which concerns on one Embodiment. It is sectional drawing which follows the EE line | wire in FIG.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples.
For example, expressions expressing relative or absolute arrangements such as “in a certain direction”, “along a certain direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” are strictly In addition to such an arrangement, it is also possible to represent a state of relative displacement with an angle or a distance such that tolerance or the same function can be obtained.
For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state.
For example, expressions representing shapes such as quadrangular shapes and cylindrical shapes represent not only geometrically strict shapes such as quadrangular shapes and cylindrical shapes, but also irregularities and chamfers as long as the same effects can be obtained. A shape including a part or the like is also expressed.
On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of other constituent elements.

1 to 13 show a heat exchanger according to some embodiments.
1 to 3 are general views of a heat exchanger according to an embodiment, FIG. 4 is a cross-sectional view taken along line AA in FIG. 2, and FIG. 5 is taken along line BB in FIG. It is sectional drawing which follows.
As shown in FIG.4 and FIG.5, the heat exchanger 10 is provided with the plate structure 12 comprised by the several laminated | stacked plate. The plate structure 12 includes a plurality of first plates 14 and a plurality of second plates 16. A plurality of first flow paths 18 are formed in each of the plurality of first plates 14, and a plurality of second flow paths 20 are formed in each of the plurality of second plates 16.

6-10 shows the 1st plate 14 which concerns on one Embodiment. 6 and 7 show the front and back surfaces of the first plate 14, FIG. 8 is an enlarged sectional view of the upstream region 18a of the first plate 14, and FIG. 9 is a sectional view taken along the line CC in FIG. FIG. 10 is a cross-sectional view taken along line DD in FIG. 8 and 9 show the first flow path 18 formed in the first plate 14.
11-13 illustrate a second plate 16 according to some embodiments. 11 and 12 show the front and back surfaces of the second plate 16, and FIG. 13 is a cross-sectional view taken along the line EE in FIG. 11, showing the second flow path 20 formed in the second plate 16. .

The first fluid is in a gas-liquid two-phase state in at least a part of the first flow path 18. A first inlet header space 22 and a first outlet header space 24 are formed in the plate structure 12. The first inlet header space 22 communicates with the first fluid supply unit 26 and the plurality of first flow paths 18 formed in each first plate 14. The first outlet header space 24 communicates with the first fluid discharge portion 28 and the plurality of first flow paths 18 formed in each first plate 14.
The plurality of first flow paths 18 are positioned on the downstream side of the upstream area 18a and the upstream area 18a formed in a waveform in which the flow path shapes meander alternately in a direction orthogonal to the flow direction, and are located on the downstream side of the upstream area 18a. And a downstream region 18b in which the flow path shape of the fluid is linearly formed.

  In the above configuration, the first fluid flows into the plurality of first flow paths 18 from the first fluid supply unit 26 through the first inlet header space 22 in a gas-liquid two-phase state. In the plurality of first flow paths 18, the first fluid exchanges heat with the second fluid flowing in the plurality of second flow paths 20 and is heated and vaporized by the second fluid, and the vaporized vapor passes through the first outlet header space 24. And flows out from the first fluid discharge part 28.

According to the above configuration, in a part of the low-quality upstream region 18a, the first fluid is not an annular flow having a high heat transfer characteristic, and the slag has a relatively high liquid ratio and bubbles are mixed in the liquid. There may be a flow state. In the upstream region 18a, the first fluid flows through the corrugated flow path to form a turbulent flow, thereby promoting heat transfer with the second fluid. The heat transfer coefficient can be particularly increased by forming the turbulent flow with the first fluid of the slag flow.
Moreover, since pressure loss increases because a 1st fluid forms turbulent flow, generation | occurrence | production of a backflow can be suppressed and the fall of a process flow rate can be suppressed by this. Furthermore, since the pressure loss increases, the variation in the pressure loss between the first flow paths is relatively relaxed, so that the drift between the plurality of first flow paths is suppressed. Thereby, the flow path with a small liquid ratio can be eliminated, and the heat transfer performance as a whole can be maintained high.

  Further, in the downstream region 18b, the plurality of first flow paths 18 are each formed in a linear shape, so that the high-quality first fluid flowing through the linear flow path has a reduced pressure loss, Air bubbles easily move downstream, and backflow is suppressed. Further, in the downstream region 18b in which the liquid content is reduced by evaporation, the corrugated flow path causes the liquid film formed on the heat transfer wall to be divided, and a dryout in which the heat transfer coefficient decreases is likely to occur. The formation of the dryout can be delayed by making the flow path shape of the downstream region 18b linear. Thereby, the heat transfer performance of the first fluid can be maintained high also in the downstream region 18b.

In one embodiment, as shown in FIGS. 4 and 5, the first flow path 18 and the second flow path 20 are configured by grooves formed in a plate.
In another embodiment, the first flow path 18 and the second flow path 20 form a slit hole penetrating the front and back of the first plate 14 or the second plate 16, and the slit hole is formed on two different sheets from both sides. It may be a channel formed by being sandwiched between plates.

In one embodiment, as shown in FIGS. 6 and 8, the plurality of first flow paths 18 include a throttle portion 30 having a reduced cross-sectional area at each inlet portion.
In some cases, the first fluid vaporizes in the first flow path 18 and rapidly expands to cause a backflow.
According to this embodiment, since the pressure loss increases in each of the plurality of first flow paths 18 in the plurality of first flow paths 18, it is possible to suppress the back flow of the first fluid, and thereby it is possible to suppress a decrease in the processing flow rate.
In the embodiment shown in FIGS. 6 and 8, the cross-sectional area of the flow path of the throttle unit 30 is reduced over the entire length, but the cross-sectional area of only a part of the flow path of the throttle unit 30 such as an orifice is reduced. It is good also as the structure which carried out.

In one embodiment, as shown in FIG. 8, in the throttling portion 30, the plurality of first flow paths 18 are formed in a wavy shape. In the figure, reference numeral 31 denotes a corrugated channel formed at the inlet of the first channel 18.
According to this embodiment, in the throttle part 30, the flow path shape of the first flow path 18 is formed in a waveform, so that the pressure loss of the first flow path 18 further increases and the throttling effect can be improved.

In one embodiment, as shown in FIG. 8, the inlet portions of the plurality of first flow paths 18 are the first when the first fluid f ₁ flowing through the first inlet header space 22 flows into the first flow path 18. It is inclined with respect to a direction orthogonal to the flow direction of the first fluid f ₁ in the first inlet header space so that the deflection angle θ of the flow of one fluid is less than 90 °.
According to this embodiment, since the deflection angle θ of the flow when the first fluid f ₁ flowing through the first inlet header space 22 flows into the first flow path 18 is less than 90 °, the first fluid f ₁ Pressure loss when flowing into the first flow path 18 from the first inlet header space 22 can be reduced. Accordingly, the difference in the distance between the first fluid supply unit 26 and the inlet of the first flow path 18 does not greatly affect the inflow amount of the first fluid f ₁ into each first flow path 18. The drift of the first fluid f ₁ in the passage 18 can be suppressed.

In one embodiment, in each first flow path 18, the boundary between the upstream region 18a and the downstream region 18b is in a region where the first fluid forms an annular flow.
According to this embodiment, since the boundary between the upstream region 18a and the downstream region 18b is in a region where the first fluid forms an annular flow having high heat transfer characteristics, the upstream region 18a has a high transfer rate. Thermal performance can be obtained. Moreover, in the downstream area | region 18b, since a flow path shape has linear form, since dryout can be delayed, the fall of heat-transfer performance can be suppressed.

In one embodiment, each of the plurality of first flow paths 18 has a boundary between the upstream region 18a and the downstream region 18b in a region where the quality of the first fluid is 0.3 or more and 0.8 or less.
According to this embodiment, the boundary between the upstream region 18a and the downstream region 18b of the first flow path 18 is a region where the quality of the first fluid is 0.3 to 0.8, that is, the first fluid is annular. By being in the region forming the flow, high heat transfer performance can be maintained between the first fluid and the second fluid in the upstream region and the downstream region.

In one embodiment, as shown in FIG. 8, the first flow path walls 32 that respectively constitute the plurality of first flow paths 18 are stacked in the stacking direction of the plate components 12 (the direction of the arrow X in FIGS. 1 and 3). When viewed from above, the second flow path walls 33 constituting the corresponding second flow paths 20 respectively overlap with at least a part of the area.
According to this embodiment, the first flow path wall 32 and the second flow path wall 33 are arranged so as to overlap each other when viewed from the stacking direction of the plate structure 12, thereby forming the first flow path 18. When the first plate 14 and the second plate 16 on which the second flow path 20 is formed are diffusion bonded, a high bonding pressure can be applied to the first flow path wall 32 and the second flow path wall 33. The bonding strength between the first plate 14 and the second plate 16 can be increased.

In one embodiment, as shown in FIG. 8, the plurality of second flow paths 20 have straight flow paths arranged along the same direction as the first flow paths 18. The first flow path walls 32 constituting the upstream regions 18 a of the plurality of first flow paths 18 are linear flow paths of the corresponding second flow paths 20 when viewed from the stacking direction of the plate structures 12. Are arranged so as to intersect with the second flow path wall 33 that constitutes a predetermined pitch (wavelength / 2) P.
According to this embodiment, the first flow path wall 32 and the second flow path wall 33 are arranged so as to intersect at a constant pitch P. Therefore, the first flow path wall 32 and the second flow path wall 33 Overlap with each other at a constant pitch P. Accordingly, since a high bonding pressure can be applied to the first flow path wall 32 and the second flow path wall 33 during diffusion bonding, the bonding strength between the first plate 14 and the second plate 16 can be increased.

  In one embodiment, the pitch P is 1 to 3 mm. According to this embodiment, since the first flow path wall 32 and the second flow path wall 33 overlap with each other with a pitch P of 1 to 3 mm, the first flow path wall 32 and the second flow path wall 33 are higher during diffusion bonding. Bonding pressure can be applied. Thereby, the bonding strength between the first plate 14 and the second plate 16 can be increased.

In one embodiment, as shown in FIGS. 2 and 6, the first outlet header space 24 forms a space penetrating along the stacking direction of the plate structure 12 including the plurality of second plates 16.
The pressure loss of the first fluid from the first inlet header space 22 to the first outlet header space 24 is caused by the pressure of each first fluid in the first inlet header space 22, the first flow path 18, and the first outlet header space 24. Total loss.

In FIG. 6, the pressure of the first fluid in the first fluid supply unit 26 is P _in , the pressure of the first fluid _in the first inlet header space 22 is P _1, and the first fluid in any first flow path 18 is a pressure of P _2, the pressure of the first fluid in the first outlet header space 24 and P _3, the pressure of the first fluid in the first fluid discharge section 28 and P _out. The pressure loss [Delta] P of the first fluid between the at all of the first flow path 18 and the first fluid supply unit 26 and the first fluid discharge section 28, the pressure loss [Delta] P ₁ of the first inlet header space 22, the first flow the pressure loss [Delta] P ₂ of the road 18, because the sum of the pressure loss [Delta] P ₃ of the first outlet header space 24, the following equation (1) and (2) holds.
ΔP = P _in −P _out
= ΔP ₁ + ΔP ₂ + ΔP ₃
= (P _in −P ₁ ) + (P ₁ −P ₃ ) + (P ₃ −P _out ) (1)
P ₁ > P ₂ > P ₃ (2)

At the outlet of the first flow path 18 through which the gas-liquid two-phase first fluid flows, the pressure loss of the first fluid is likely to increase due to the first fluid becoming steam in the first flow path 18. Accordingly, the first outlet header space first fluid pressure loss [Delta] P ₃ of the 24 large, pressure loss difference between the plurality of first flow path 18 increases.
Since the first outlet header space 24 forms a space penetrating along the plate stacking direction, the pressure loss ΔP ₃ of the first outlet header space 24 can be reduced. As a result, the proportion of the first fluid pressure loss ΔP ₂ in the first flow path 18 relatively increases.
In addition, since the pressure loss ΔP ₃ in the first outlet header space 24 is reduced, the first fluid is likely to flow into the first outlet header space 24 from the first flow path 18. The difference in pressure loss at the outlet is also reduced.

  Thereby, the uneven flow between the plurality of first flow paths can be suppressed, and heat transfer between the first flow path and the second flow path in a part of the first flow paths caused by the uneven flow of the first fluid between the first flow paths. A decrease in performance can be suppressed. Therefore, since the heat transfer performance between the plurality of first flow paths can be made uniform, the heat transfer performance can be maintained high as the entire first flow path.

In one embodiment, the first inlet header space 22 is divided along the stacking direction of the plate structure 12 by the plurality of second plates 16.
According to this embodiment, since the first inlet header space 22 is divided along the plate stacking direction by the plurality of second plates 16, the first inlet space 22 flows into the first flow path 18 between the plurality of first plates 14. It is possible to balance the flow rate of one fluid, thereby improving the drift suppression effect between the plurality of first flow paths.

In one embodiment, as shown in FIGS. 4 and 5, the plurality of first plates 14 and the plurality of second plates 16 are alternately arranged along the plate stacking direction.
According to this embodiment, the plurality of first plates 14 and the plurality of second plates 16 are alternately arranged along the plate stacking direction, so that the first flow path 18 is provided between the plurality of first plates. The volume of the first inlet header space 22 that communicates can be divided equally. Accordingly, the flow rate of the first fluid flowing into the first flow path 18 can be equalized between the plurality of first plates, so that the effect of suppressing the drift between the plurality of first flow paths can be improved.
In addition, since the first plate 14 through which the first fluid flows and the second plate 16 through which the second fluid flows are alternately arranged adjacent to each other in a laminated structure, the heat transfer area of the first fluid and the second fluid can be increased. Thereby, heat transfer performance can be improved.

In one embodiment, as shown in FIGS. 6 and 7, the first inlet header space 22 flows as the distance between the plurality of first flow paths 18 and the first fluid supply portions 26 increases in each first plate 14. The road cross-sectional area is configured to gradually decrease.
According to this embodiment, since the first inlet header space 22 has a tapered structure, the first fluid is distributed to the plurality of first flow paths 18 formed in each first plate 14, and the first inlet header space 22 is formed. Even if the flow rate of the first fluid 22 decreases, it is possible to suppress a decrease in the flow rate of the first fluid in the first inlet header space 22. Accordingly, an annular flow can be formed in the first inlet header space 22, and an annular flow is formed in the first inlet header space 22, thereby suppressing uneven flows between the plurality of first flow paths. Therefore, the heat transfer performance of the first fluid and the second fluid can be maintained high in the plurality of first flow paths 18.

  Further, in a structure in which a plurality of plates are stacked to form a flow path, by adopting a tapered structure, it is possible to easily cope with a large increase or decrease in the number of plates, and a complicated header structure is not obtained. This makes it possible to reliably supply the first fluid that can suppress the drift between the first flow paths.

In one embodiment, as shown in FIGS. 6 and 7, the first fluid supply unit 26 and the first fluid discharge unit 28 are formed along the stacking direction of the plate structures 12.
According to this embodiment, the first fluid supply part 26 and the first fluid discharge part 28 are formed in the plate structure 12 so that the first fluid supply part 26 and the first fluid discharge part 28 are separate structures. There is no need to install the plate structure 12 outside. Furthermore, the piping that connects the first fluid supply unit 26 and the first inlet header space 22 and the piping that connects the first fluid discharge unit 28 and the first outlet header space 24 become unnecessary. Thereby, the heat exchanger 10 can be reduced in size and cost.

In one embodiment, as shown in FIG. 6, in each first plate 14, the plurality of first flow paths 18 are arranged in parallel to each other. Moreover, as shown in FIG. 11, in each 2nd plate 16, the several 2nd flow path 20 is mutually arrange | positioned in parallel.
According to this embodiment, the plurality of first flow paths 18 and the plurality of second flow paths 20 are arranged in parallel, so that the first flow path 18 and the second flow path 20 extend over the entire length of the flow path. Can be placed close together. Thereby, the heat transfer performance between the first fluid and the second fluid can be improved.
In particular, the effect of suppressing the drift between the plurality of first flow paths can be improved by the combination of the parallel arrangement of the plurality of first flow paths 18 and the tapered structure of the first inlet header space 22.

In one embodiment, the plurality of first channels 18 and the plurality of second channels 20 are arranged in parallel at the same interval.
In one embodiment, the 1st channel 18 and the 2nd channel 20 are arranged in the position which overlaps in the plate lamination direction. Thereby, since the 1st flow path 18 and the 2nd flow path 20 can be arrange | positioned in the closest position, the heat transfer performance of a 1st fluid and a 2nd fluid can be maximized.

In one embodiment, at least some of the plurality of first flow paths 18 formed in the first inlet header space 22 and the plurality of first plates 14 form a first fluid annular flow in these flow fields. Configured. The configuration of the first inlet header space 22 and the first flow path 18, the type of the first fluid flowing through these flow paths (for example, the selection of the type based on the density, the viscosity coefficient, etc.) and the operating conditions (for example, the flow rate of the first fluid) , Flow velocity, etc.) are determined by, for example, a Baker diagram representing the flow mode of gas-liquid two-phase flow.
According to the above configuration, since the first fluid forms an annular flow in the first inlet header space 22 and the first flow path 18, the gas and liquid are mixed in these flow fields, and the gas and liquid are separated. Absent. Therefore, since the gas-liquid mixing ratio can be maintained uniformly between the first inlet header space 22 and the plurality of first flow paths, the heat exchange efficiency between the first fluid and the second fluid can be improved as a whole.

In one embodiment, as shown in FIGS. 5, 8 to 10, and 13, the plurality of first flow paths 18 formed in the plurality of first plates 14 and the plurality of second plates 16 are formed. The maximum width of the plurality of second flow paths 20 is 2 mm or less (preferably 0.1 to 1.0 mm).
According to this embodiment, by forming the first flow path 18 and the second flow path 20 as fine flow paths having a maximum width of 2 mm or less, a large number of first flow paths can be formed in the first plate 14, and Many second flow paths 20 can be formed in the two plates 16. Thereby, since the heat transfer area of these flow paths can be dramatically increased, the heat exchange efficiency between the first fluid and the second fluid can be dramatically increased.

Preferably, the maximum width of the first flow path 18 and the second flow path 20 is 1 mm or less in order to increase the heat transfer performance. Preferably, from the viewpoint of ease of processing the first flow path 18 and the second flow path 20, the width of the first flow path 18 and the second flow path 20 is set to 0.1 mm or more.
In the illustrated embodiment, the first channel 18 and the second channel 20 have a semicircular cross section, but may have other cross sectional shapes such as a square.

In one embodiment, as shown in FIGS. 2, 6 and 11, 12, the second fluid supply unit 34 and the second inlet header space 38 that communicates with the second fluid supply unit 34 and the plurality of second flow paths 20. The second fluid discharge portion 36 and the second outlet header space 40 communicating with the second fluid discharge portion 36 and the plurality of second flow paths 20 are formed in the plate structure 12.
Further, the second inlet header space 38 and the second outlet header space 40 are disposed on both sides of the plurality of first flow paths 18 along the direction intersecting with the plurality of first flow paths 18. Furthermore, as shown in FIG. 11, the plurality of second flow paths 20 include an inlet-side area 20 a and an outlet-side area 20 c that are arranged along a direction intersecting with the plurality of first flow paths 18, and a plurality of first flow paths. And an intermediate region 20b disposed along the same direction as the flow path 18.

According to this embodiment, since the second inlet header space 38 and the second outlet header space 40 of the second flow path 20 are arranged along the direction intersecting the first flow path 18, the second inlet header space 38. The second outlet header space 40 can be arranged without interfering with the first inlet header space 22 and the first outlet header space 24 of the first flow path 18. Therefore, the freedom degree of arrangement | positioning of the 2nd entrance header space 38 and the 2nd exit header space 40 can be expanded.
Further, since the intermediate region 20b of the second flow channel 20 is disposed along the same direction as the first flow channel 18, the first flow channel 18 and the second flow channel 20 can be disposed close to each other, and therefore, the intermediate region 20b. The heat transfer performance between the first fluid and the second fluid can be improved.

  Furthermore, since the inlet side region 20 a and the outlet side region 20 c of the second flow path 20 are arranged along the direction intersecting the first flow path 18, the first flow path wall 32 configuring the first flow path 18. And the second flow path wall 33 constituting the second flow path 20 overlap at a constant pitch. Accordingly, when the first plate 14 and the second plate 16 are diffusion bonded, a high bonding pressure can be applied to the first flow path wall 32 and the second flow path wall 33. Thereby, the bonding strength between the first plate 14 and the second plate 16 can be increased.

In one embodiment, the first fluid is NH ₃ , the second fluid is CO ₂ , and the heat exchanger 10 is NH ₃ / CO _{2 where the} primary refrigerant is NH ₃ and the secondary refrigerant is CO ₂ , for example. It is a CO ₂ liquefier that is provided in a refrigerator and heats and vaporizes the primary refrigerant by exchanging heat between the gas-liquid two-phase primary refrigerant and the secondary refrigerant.
In this CO ₂ liquefier, the uneven flow can be suppressed between the plurality of flow paths through which the gas-liquid two-phase NH ₃ flows, whereby the heat transfer performance of the plurality of first flow paths 18 can be made uniform and the first flow Since the pressure loss of the path 18 can be suppressed, the heat transfer performance between the primary refrigerant and the secondary refrigerant can be maintained high.
NH ₃ with a large gas-liquid density ratio is particularly prone to drift, but even NH ₃ can suppress drift between a plurality of flow paths, and form a dryout that reduces heat transfer in the downstream area of the flow paths. Therefore, the heat transfer performance of NH ₃ and CO ₂ can be maintained high.

  In one embodiment, as shown in FIG. 1, end plates 42 and 44 are provided on both side surfaces of the plate structure 12. As shown in FIG. 2, one end plate 42 has a hole 46 communicating with the first fluid supply unit 26, a hole 48 communicating with the first fluid discharge unit 28, and a hole 50 communicating with the second fluid supply unit 34. And a hole 52 communicating with the second fluid discharge part 36 is formed. A first fluid inlet pipe 54 is provided so as to surround the hole 46, a first fluid outlet pipe 56 is provided so as to surround the hole 48, and a second fluid inlet pipe 58 is provided so as to surround the hole 50, A second fluid outlet pipe 60 is provided so as to surround the hole 52.

In one embodiment, the first fluid inlet tube 54 is connected upstream to a first fluid supply tube (not shown) and the first fluid outlet tube 56 is connected downstream to a first fluid discharge tube (not shown). The The second fluid inlet pipe 58 is connected to the second fluid supply pipe (not shown) on the upstream side, and the second fluid outlet pipe 60 is connected to the second fluid discharge pipe (not shown) on the downstream side.
In one embodiment, the end plates 42 and 44 are constituted by flat plate-like bodies, and the end plate 44 is constituted by a plate-like body having no holes or openings.

In one embodiment, as shown in FIGS. 1 and 3, the first plate 14 and the second plate 16 are formed of flat plate-like bodies.
In one embodiment, the first plate 14, the second plate 16, and the end plates 42 and 44 are bonded to each other by a diffusion bonding method. By adopting the diffusion bonding method, the plurality of types of plates can be bonded in one step.
In one embodiment, as shown in FIGS. 1 and 3, the first plate 14, the second plate 16, and the end plates 42 and 44 have a rectangular outer shape.

In one embodiment, as shown in FIG. 1, the heat exchanger 10 includes a first fluid inlet pipe 54 through which the first fluid f ₁ flows and a second fluid outlet pipe 60 through which the second fluid f ₂ flows downward. The first fluid outlet pipe 56 and the second fluid inlet pipe 58 are arranged along the vertical direction so that the first fluid outlet pipe 56 and the second fluid inlet pipe 58 are arranged upward.
In one embodiment, the first plate 14 and the second plate 16 are made of a material having a high thermal conductivity coefficient and high strength. Thereby, the heat transfer performance is good and the first plate 14 and the second plate 16 can be made thin.

  According to one embodiment, in the heat exchanger in which one of the fluids is a gas-liquid two-phase fluid and the gas-liquid two-phase fluid is divided into a plurality of flow paths to exchange heat, the plurality of heat exchange flow paths Heat transfer performance can be maintained high by suppressing the drift of the inflowing gas-liquid two-phase fluid.

DESCRIPTION OF SYMBOLS 10 Heat exchanger 12 Plate structure 14 1st plate 16 2nd plate 18 1st flow path 18a Upstream area | region 18b Downstream area | region 20 2nd flow path 20a Inlet side area | region 20b Middle area | region 20c Outlet side area | region 22 1st inlet header Space 24 First outlet header space 26 First flow path supply section 28 First flow path discharge section 30 Restriction section 31 Waveform flow path 32 First flow path wall 33 Second flow path wall 34 Second flow path supply section 36 Second Flow path discharge part 38 Second inlet header space 40 Second outlet header space 42, 44 End plate 46, 48, 50, 52 Hole 54 First fluid inlet pipe 56 First fluid outlet pipe 58 Second fluid inlet pipe 60 Second Fluid outlet pipe P Pitch X Stacking direction f ₁ First fluid f ₂ Second fluid θ Deflection angle

Claims (19)

A heat exchanger for exchanging heat between the first fluid and the second fluid to vaporize the first fluid,
A plurality of stacked layers including a plurality of first plates forming a plurality of first flow paths through which the first fluid flows, and a plurality of second plates forming a plurality of second flow paths through which the second fluid flows. Comprising a plate structure composed of
The first fluid is in a gas-liquid two-phase state in at least a part of the first flow path;
A first inlet header space communicating with the first fluid supply section and the plurality of first flow paths formed in each of the plurality of first plates; the first fluid discharge section; A first outlet header space communicating with the plurality of first flow paths formed in each of the one plate is formed in the plurality of first plates;
Each of the plurality of first flow paths includes an upstream area in which the flow path shape is formed in a waveform, and a downstream area in which the flow path shape is formed in a straight line and located downstream of the upstream area, The heat exchanger characterized by having.   The heat exchanger according to claim 1, further comprising a throttle portion at an inlet portion of each of the plurality of first flow paths.   3. The heat exchanger according to claim 2, wherein each of the plurality of first flow paths is formed in a wavy shape in the throttle portion.   Each inlet of each of the plurality of first flow paths has an angle between a flow direction of the first fluid flowing through the first inlet header space and a flow direction of the first fluid when flowing into the first flow path. 4. The device according to claim 1, wherein the angle of inclination is less than 90 ° with respect to a direction perpendicular to the flow direction of the first fluid in the first inlet header space. 5. The heat exchanger according to one item.   The boundary between the upstream region and the downstream region of each of the plurality of first flow paths is in a region where the first fluid forms an annular flow. The heat exchanger as described in any one.   The boundary between the upstream region and the downstream region of each of the plurality of first flow paths is in a region where the quality of the first fluid is 0.3 or more and 0.8 or less. The heat exchanger according to any one of 1 to 5.   The first flow path wall constituting each of the plurality of first flow paths is a second flow path wall constituting each of the corresponding plurality of second flow paths when viewed from the stacking direction of the plate constituents. The heat exchanger according to any one of claims 1 to 6, wherein the heat exchanger overlaps with at least a part of the region. Each of the plurality of second flow paths includes a linear flow path disposed along the same direction as the first flow path,
The first flow path wall constituting the upstream region of each of the plurality of first flow paths is the straight line of each of the corresponding second flow paths when viewed from the stacking direction of the plate structure. The heat exchanger according to any one of claims 1 to 7, wherein the heat exchanger is disposed so as to intersect with a second flow path wall that forms a solid flow path at a constant pitch.   The heat exchanger according to claim 8, wherein the pitch is 1 mm or more and 3 mm or less.   The said 1st exit header space forms the space penetrated along the lamination direction of the said plate structure including the said several 2nd plate, The any one of Claim 1 thru | or 9 characterized by the above-mentioned. The described heat exchanger.   The heat exchanger according to any one of claims 1 to 10, wherein the first inlet header space is divided by the plurality of second plates along a stacking direction of the plate components.   The heat according to any one of claims 1 to 11, wherein the plurality of first plates and the plurality of second plates are alternately arranged along a stacking direction of the plate structures. Exchanger.   The first inlet header space is configured such that in each of the plurality of first plates, a channel cross-sectional area gradually decreases as the distance between each of the plurality of first channels and the supply unit increases. The heat exchanger according to claim 1, wherein the heat exchanger is a heat exchanger.   The said plate structure is formed with the said supply part of the said 1st fluid, and the said discharge part of the said 1st fluid along the lamination direction of the said plate structure, The any one of Claims 1 thru | or 13 characterized by the above-mentioned. The heat exchanger according to item. In each of the plurality of first plates, each of the plurality of first flow paths is arranged in parallel with each other,
The heat exchanger according to any one of claims 1 to 14, wherein in each of the plurality of second plates, the plurality of second flow paths are arranged in parallel to each other.   At least a part of the plurality of first flow paths formed in the first inlet header space and the plurality of first plates is the first fluid flowing through the first inlet header space and the plurality of first flow paths. The heat exchanger according to claim 1, wherein the heat exchanger is configured to form an annular flow.   The maximum width of the plurality of first flow paths formed in the plurality of first plates and the plurality of second flow paths formed in the plurality of second plates is 2 mm or less. The heat exchanger according to any one of 1 to 16. A second fluid supply section; a second inlet header space communicating with each of the supply section and the plurality of second flow paths; a discharge section for the second fluid; the discharge section; and the plurality of second sections. A second outlet header space communicating with each of the flow paths is formed in the plate structure,
The second inlet header space and the second outlet header space are disposed on both sides of the plurality of first flow paths along a direction intersecting with each of the plurality of first flow paths.
Each of the plurality of second flow paths is
An inlet side region and an outlet side region disposed along a direction intersecting with each of the plurality of first flow paths;
An intermediate region disposed along the same direction as each of the plurality of first flow paths;
The heat exchanger according to any one of claims 1 to 17, characterized by comprising: The first fluid is NH ₃ and the second fluid is CO ₂ ;
The heat exchanger according to any one of claims 1 to 18, characterized in that a CO ₂ liquefier vaporizing the first fluid and the second fluid and the first fluid by heat exchange Heat exchanger.

Images