HEAT EXCHANGER

Abstract

The heat exchanger is provided with: a plurality of first members including walls that have introduction holes on a first end side and discharge holes on a second end side, with spaces connecting the introduction holes and the discharge holes serving as first channels through which fluid flows; second members that communicate with the introduction holes at the first end side of the plurality of first members to introduce the first fluid to the first members; and third members that communicate with the discharge holes at the second end side of the plurality of first members to discharge the first fluid that has flowed through the first members. In at least one adjacent pair of the introduction holes, regions that overlap with opening regions of the upstream-side introduction holes exist in the walls including the downstream-side introduction holes, when viewed in a direction in which the first fluid flows.

Description

TECHNICAL FIELD

The present invention relates to a heat exchanger.

BACKGROUND ART

Conventionally, heat exchangers have been used in heat exchange systems for cooling, heating, and the like. As an example of such a heat exchanger, there has been proposed a heat exchanger formed by a plurality of substrates that are laminated. Each of the substrates has a plurality of strips arranged substantially parallel side by side as well as slits between the strips, and is provided with recesses that continue in a longitudinal direction on several surfaces of the strips. The strips of adjacent substrates are interconnected to define tubes, the recesses define tube internal channels, and the slits define tube external channels. (Refer to Patent Document 1, for example.)

CITATION LIST

Patent Literature

Patent Document 1: Japanese Unexamined Patent Application No. 2005-300062A

SUMMARY OF INVENTION

Technical Problem

In the heat exchangers of recent years, an even superior heat exchange efficiency has been in demand. An object of the present invention is therefore to provide a heat exchanger having a superior heat exchange efficiency.

Solution to Problem

A heat exchanger according to the present invention is formed from a ceramic and performs heat exchange between a first fluid and a second fluid. The heat exchanger is provided with a plurality of first members including walls that have introduction holes on a first end side and discharge holes on a second end side, with spaces connecting the introduction holes and the discharge holes serving as first channels through which the first fluid flows; second members that communicate with the introduction holes at the first end side of the plurality of first members to introduce the first fluid to the first members; and third members that communicate with the discharge holes at the second end side of the plurality of first members to discharge the first fluid that has flowed through the first members. In such a heat exchanger, spaces between the plurality of first members serve as second channels through which the second fluid flows. Further, in at least one adjacent pair of the introduction holes, regions that overlap with opening regions of upstream-side introduction holes exist in the walls including downstream-side introduction holes, when viewed in a direction in which the first fluid flows.

A heat exchanger according to the present invention is formed from a ceramic and performs heat exchange between a first fluid and a second fluid. The heat exchanger is provided with a plurality of first members including walls that have introduction holes on a first end side and discharge holes on a second end side, with spaces connecting the introduction holes and the discharge holes serving as first channels through which the first fluid flows; second members that communicate with the introduction holes at the first end side of the plurality of first members to introduce the first fluid to the first members; and third members that communicate with the discharge holes at the second end side of the plurality of first members to discharge the first fluid that has flowed through the first members. In such a heat exchanger, spaces between the plurality of first members serve as second channels through which the second fluid flows. Further, in at least one adjacent pair of the discharge holes, regions that overlap with opening regions of upstream-side discharge holes exist in the walls including downstream-side discharge holes, when viewed in a direction in which the first fluid flows.

Advantageous Effects of Invention

The heat exchanger according to the present invention has a superior heat exchange efficiency.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating an example of a heat exchanger according to a present embodiment.

FIG. 2 is a cross-sectional view illustrating an example of the heat exchanger according to the present embodiment.

FIG. 3 is a perspective view illustrating an example of a first member that constitutes the heat exchanger according to the present embodiment.

FIG. 4 is a perspective view illustrating an example of a second member and a third member that constitute the heat exchanger according to the present embodiment.

FIG. 5 is a partial cross-sectional view illustrating an example of the heat exchanger according to the present embodiment.

FIG. 6 is an enlarged partial cross-sectional view illustrating an example of the second member side of the heat exchanger according to the present embodiment.

FIG. 7 is an enlarged partial cross-sectional view illustrating another example of the second member side of the heat exchanger according to the present embodiment.

A heat exchanger according to the present embodiment will be described hereinafter using the drawings. Note that, in the following descriptions, identical members in the drawings will be denoted using the same symbols.

FIG. 1 is a perspective view and FIG. 2 is a cross-sectional view illustrating an example of a heat exchanger according to the present embodiment. Further, FIG. 3 is a perspective view illustrating an example of a first member constituting the heat exchanger according to the present embodiment, and FIG. 4 is a perspective view illustrating an example of a second member and a third member that constitute the heat exchanger according to the present embodiment. Further, FIG. 5 is a partial cross-sectional view of the heat exchanger according to the present embodiment, and FIGS. 6 and 7 are enlarged partial cross-sectional views of the second member side of the heat exchanger according to the present embodiment.

First, the configuration of the heat exchanger according to the present embodiment will be described using FIGS. 1 and 2. A heat exchanger 1 of the example illustrated in FIG. 1 includes a plurality of first members 2. Each of the first members 2 includes walls provided with introduction holes 5 on a first end side and discharge holes 6 on a second end side. Spaces connecting the introduction holes 5 and the discharge holes 6 serve as first channels 8 through which a first fluid flows. The heat exchanger 1 further includes second members 3 that communicate with the introduction holes 5 at the first end side of the plurality of first members 2 to introduce the first fluid to the first members 2. The heat exchanger 1 further includes third members 4 that communicate with the discharge holes 6 at the second end side of the plurality of first members 2 to discharge the first fluid that has flowed through the first members 2. Further, spaces between the plurality of first members 2 serve as second channels 10 through which a second fluid flows. Note that the “first end side” here can also be expressed as an upstream side of the first fluid, and the “second end side” can also be expressed as a downstream side of the first fluid.

While the heat exchanger 1 that includes three first members 2 is illustrated in FIGS. 1 and 2 as an example, the heat exchanger 1 is not limited thereto and may include two or more first members 2. Further, a fluid, a vapor, or the like may be used as the first fluid and the second fluid, in accordance with the objective. For example, the first fluid may be a fluid such as water, and the second fluid may be a vapor such as gas.

The first members 2, the second members 3, and the third members 4 that constitute the heat exchanger 1 according to the present embodiment are formed from a ceramic. With these members thus formed from a ceramic, the heat exchanger 1 has superior thermal resistance and corrosion resistance. The types of ceramics used can be selected as appropriate in accordance with the characteristics of the fluid. Examples include an oxide ceramic, such as an alumina ceramic or a cordierite ceramic, and a non-oxide ceramic, such as a silicon nitride ceramic, an aluminum nitride ceramic, or a silicon carbide ceramic.

When these members are formed from a silicon carbide ceramic having a silicon carbide content exceeding 50 mass % with respect to all components that constitute the ceramic, the heat exchange efficiency of the heat exchanger 1 can be increased due to a high thermal conductivity. Further, when these members are formed from an alumina ceramic having an alumina content exceeding 50 mass % with respect to all components that constitute the ceramic, the raw material cost decreases and machineability increases, thus the heat exchanger 1 can be manufactured at a cost lower than that when other materials are used.

FIGS. 1 and 2 illustrate an example in which the heat exchanger 1 includes a flange portion 16 at the lowest level. The flange portion 16 includes an introduction portion 11 and a discharge portion 12 for the first fluid. The path of the first fluid in this example will now be described. First, the first fluid enters the heat exchanger 1 from the introduction portion 11 of the flange portion 16, flows through an introduction channel 7, passes through the introduction holes 5 and the first channels 8 of the first members 2, flows through the discharge holes 6, and is then discharged from the discharge portion 12 via a discharge channel 9.

By satisfying such a configuration, the heat exchanger 1 of the present embodiment can perform heat exchange efficiently with the second fluid that flows through the second channel 10 while the first fluid flows through the first channel 8, in particular.

Further, when a channel that connects the introduction portion 11 and the discharge portion 12 is provided in the flange portion 16, heat exchange can be performed in the flange portion 16 as well. Thus, the heat exchange efficiency of the heat exchanger 1 can be improved. Note that the flange portion 16 is not mandatory in a configuration of the heat exchanger 1. The opening of the second member 3 positioned at the lowest level in FIGS. 1 and 2 may serve as the introduction port of the first fluid, and the opening of the third member 4 positioned at the lowest level may serve as the discharge port of the first fluid.

Further, in the heat exchanger 1, the first fluid and the second fluid can be disposed so as to form a cross flow, or disposed so as to flow in the same direction.

Further, while not illustrated in FIGS. 1 and 2, a partition portion capable of branching the first fluid may be provided in the first member 2. When the partition portion is thus provided, a contact surface area with the first fluid is increased. Thus, the heat exchange efficiency can be improved.

Next, each member that constitutes the heat exchanger according to the present embodiment will be described using FIGS. 3 and 4. First, the first member 2 includes the introduction hole 5 that communicates with the second member 3, and the discharge hole 6 that communicates with the third member 4, as illustrated in FIG. 3. Note that while FIG. 3 illustrates an example in which the introduction hole 5 and the discharge hole 6 are provided in mutually corresponding positions of an upper wall and a lower wall, forming through-holes, the first member 2 of this configuration corresponds to a first member 2b and a first member 2c in FIGS. 1 and 2. Further, the first member 2a disposed on the highest level does not require the first fluid to flow further upward on the upstream side, and the first fluid never flows from above on the downstream side. Thus, the introduction hole 5 and the discharge hole 6 are included only on the lower wall of the walls constituting the first member 2a.

Next, the second member 3 and the third member 4 are, for example, cylindrical members, as illustrated in FIG. 4. Note that a cross section of each of the second members 3 and the third members 4 orthogonal to the direction in which the first fluid flows is not limited to a circular shape. As long as the first fluid can flow through the interior and the height allows provision of the second channel 10, the cross section may be an elliptical shape, a polygonal shape such as a triangular shape or a quadrilateral shape, or the like.

Then, in addition to the configuration described above, in the heat exchanger 1 of the present embodiment, in at least one adjacent pair of the introduction holes 5, regions that overlap with opening regions of the upstream-side introduction holes exist in the walls including the downstream-side introduction holes, when viewed in the direction in which the first fluid flows. With satisfaction of such a configuration, when the first fluid flows through the introduction channel 7, the first fluid collides with the regions that overlap with the opening regions of the upstream-side introduction holes in the walls including the downstream-side introduction holes, causing change in the flow of the first fluid and, as a result, turbulence occurs. Then, the number of opportunities for contact between the first fluid and an inner face (hereinafter referred to as “turbulence region”) of the channel that comes into contact with the generated turbulence increases. As a result, the heat exchanger 1 of the present embodiment has a superior heat exchange efficiency.

Here, the one adjacent pair of the introduction holes 5, according to the heat exchanger 1 illustrated in FIG. 2, are an introduction hole 5a and an introduction hole 5b, the introduction hole 5b and an introduction hole 5c, the introduction hole 5c and an introduction hole 5d, or the introduction hole 5d and an introduction hole 5e, and are thus two of the introduction holes 5 adjacently positioned in the direction in which the first fluid flows.

Further, of the one adjacent pair of the introduction holes 5, the upstream-side introduction hole is the introduction hole 5 positioned upstream in the direction in which the first fluid flows, and the downstream-side introduction hole is the introduction hole 5 positioned downstream in the direction in which the first fluid flows. For example, for the combination of the introduction hole 5b and the introduction hole 5c, the introduction hole 5b is the downstream-side introduction hole, and the introduction hole 5c is the upstream-side introduction hole. Further, for the combination of the introduction hole 5c and the introduction hole 5d, the introduction hole 5c is the downstream-side introduction hole, and the introduction hole 5d is the upstream-side introduction hole. Thus, the same introduction hole 5 may be an upstream-side introduction hole as well as a downstream-side introduction hole, depending on the combination.

Examples in which the one adjacent pair of the introduction holes 5 satisfy the configuration described above include when the adjacent pair of the introduction holes 5 have the same opening shape and the opening region of the upstream-side introduction hole is larger than the opening region of the downstream-side introduction hole, and when the opening shapes of the adjacent pair of the introduction holes 5 are different. From the viewpoint of not delaying the flow rate of the fluid more than necessary, however, a case where the adjacent pair of the introduction holes 5 have the same opening shape, but the centers of the pair of the introduction holes 5 are shifted in a direction that intersects the direction of flow when viewed in the direction in which the first fluid flows is preferred. Note that the opening shape of the introduction hole 5 is not limited to a circular shape as illustrated in FIG. 3, and may be an elliptical shape, a polygonal shape such as a triangular shape or a quadrilateral shape, or the like.

Next, a configuration in which, in the adjacent pair of the introduction holes 5, a region that overlaps with the opening region of the upstream-side introduction hole exists in the wall including the downstream-side introduction hole, when viewed in the direction in which the first fluid flows, will be described using FIG. 5. Note that while FIG. 5 illustrates an example in which the first member 2b includes three walls, the number of walls that constitute the first member 2b is not limited thereto, and may be three or greater.

As illustrated in FIG. 5, when the adjacent pair of the introduction holes 5 are the introduction hole 5b and the introduction hole 5c, the introduction hole 5b is the downstream-side introduction hole and the introduction hole 5c is the upstream-side introduction hole. Then, “in the adjacent pair of the introduction holes 5, a region that overlaps with the opening region of the upstream-side introduction hole exists in the wall including the downstream-side introduction hole, when viewed in the direction in which the first fluid flows” refers to when the opening region of the introduction hole 5c (which is the upstream-side introduction hole) is moved in parallel in the direction in which the first fluid flows to a wall 13b that includes the downstream-side introduction hole, and when a section that overlaps with the opening region of the upstream-side introduction hole exists in the wall 13b. In other words, according to the above-described configuration, when the opening region of the introduction hole 5c is moved in parallel toward the introduction hole 5b in the direction in which the first fluid flows, a section in which there is no overlap with the opening region of the introduction hole 5b exists.

According to the example illustrated in FIG. 5, a portion of the first fluid that has passed through a second member 3b and the introduction hole 5b, when viewed in the direction in which the first fluid flows, collides with the wall 13b where the region that overlaps with the opening region of the introduction hole 5c exists, forming turbulence regions on the inner face of a second member 3a as well as on the inner face of the first member 2b, which are adjacent to the section where the colliding occurred. Then, in such a turbulence region, the number of opportunities for contact with the first fluid increases, thereby improving the heat exchange efficiency of the heat exchanger 1.

Note that while the above has been described using FIG. 5 and thus describes the introduction holes 5 of the first member 2b, the same effect as described above can be achieved with the other combinations as well as long as, in the adjacent pair of the introduction holes 5, a region that overlaps with the opening region of the upstream-side introduction hole exists in the wall that includes the downstream-side introduction hole, when viewed in the direction in which the first fluid flows. Further, from the viewpoint of expanding the turbulence regions, preferably the overlapping region described above has a surface area equivalent to at least 10% the surface area of the opening region of the upstream-side introduction hole.

Then, while a description has been given using the adjacent pair of the introduction holes 5, the same effect as described above can be achieved with the adjacent pair of the discharge holes 6 as well as long as, in at least one adjacent pair of the discharge holes 6, a region that overlaps with the opening region of the upstream-side discharge hole exists in the wall that includes the downstream-side discharge hole, when viewed in the direction in which the first fluid flows.

Further, in the heat exchanger 1 of the present embodiment, preferably the at least one of the plurality of first members 2 includes a chamfered area on a center section thereof, on an edge of the introduction hole 5 positioned on the downstream side of the first fluid, the edge being on an interior side of the first member 2.

The above-described configuration will now be described using FIG. 6. In FIG. 6, the first fluid flows from the lower introduction hole 5c into the first member 2b, and branches and flows to the first channel 8 extending from a first end side to a second end side, and to the upper introduction hole 5b. At this time, a chamfered portion 14 is provided to the center section of the first member 2b (the right side in FIG. 6), on the edge of the introduction hole 5b of the wall 13b that constitutes the first member 2b, and thus the first fluid can be smoothly branched. Note that the chamfered portion 14 serving as a chamfered area is a section in which a corner portion serving as the edge is cut to form a plane.

Thus, because the first fluid can be smoothly branched by providing the chamfered portion 14 to the center section of the first member 2b, on the edge of the introduction hole 5b positioned on the downstream side of the first fluid, the edge being on the interior side of the first member 2b, a configuration in which turbulence occurs further on the upstream side of the first fluid than the chamfered portion 14 is preferred. With such a configuration, the first fluid in which a turbulence has occurred is smoothly branched and the turbulence region is expanded, and thus, the heat exchange efficiency can be further improved.

Further, while not illustrated, the same can be said for the discharge channel 9 as well. Thus, at least one of the plurality of first members 2 includes a chamfered area on the center section thereof, on the edge of the discharge hole 6 positioned on the downstream side of the first fluid, the edge being on the interior side of the first member 2. Thus, the first fluid that has flowed through the first channel 8 and the first fluid that has flowed from the upper discharge hole 6 can be smoothly merged.

Further, in the heat exchanger 1 of the present embodiment, preferably at the least one of the plurality of first members 2 includes a protruding area at a position on the center section thereof, in an area around the edge of the introduction hole 5 positioned on the downstream side of the first fluid, the edge being on an interior side of the first member 2. In the following, this protruding area is described as a protruding portion 15.

The above-described configuration will now be described using FIG. 7. In FIG. 7, the first fluid flows from the lower introduction hole 5c into the first member 2b, and branches and flows to the first channel 8 extending from the first end side to the second end side, and to the upper introduction hole 5b. At this time, because the protruding portion 15 is provided to a position on the center section of the first member 2b, in an area around the edge of the introduction hole 5b of the wall 13b that constitutes the first member 2b, turbulence can be generated even when the first fluid branches to the first channel 8, and thus, the heat exchange efficiency can be further improved. Here, given the inner face of the wall 13b that constitutes the first member 2b, excluding the area around the edge of the introduction hole 5b, as a reference plane, the protruding portion 15 is an area of this wall 13b that protrudes at least 1 μm on the first channel 8 side of this reference plane.

Further, while not illustrated, when the at least one of the plurality of first members 2 includes the protruding portion 15 at a position on the center section thereof, in an area around the edge of the introduction hole 5 positioned on the downstream side of the first fluid, the edge being on the interior side of the first member 2, turbulence occurs from a merge with a main flow that flows through the first channel 8 and a merge with the first fluid that has flowed from the upper discharge hole 6 when the first fluid that has flowed through the first channel 8 passes over the protruding portion 15, thereby improving the heat exchange efficiency.

Further, in the heat exchanger 1 of the present embodiment, preferably the inner face of the introduction hole 5 adjacent to the second member 3 on the downstream side of first fluid has an arithmetic mean roughness Ra2 that is greater than an arithmetic mean roughness Ra1 of the inner face of the second member 3.

A description is given below, using FIG. 5. In the configuration illustrated in FIG. 5, when the arithmetic mean roughness Ra2 of the inner face of the introduction hole 5c is greater than the arithmetic mean roughness Ra1 of the inner face of the second member 3b, turbulence occurs when the first fluid flows from the interior of the second member 3b into the introduction hole 5c, and thus, the heat exchange efficiency can be improved. In particular, the introduction hole 5c is preferably included in the turbulence region that occurs due to the existence of the region that overlaps with the opening region of the upstream-side introduction hole in the wall that includes the downstream-side introduction hole.

Further, when an arithmetic mean roughness Ra4 on the inner face of the discharge hole 6 on the downstream side of the first fluid adjacent to the third member 4 is greater than an arithmetic mean roughness Ra3 of the inner face of the third member 4 in the discharge channel 9 as well, turbulence occurs when the first fluid flows from the interior of the third member 4 into the discharge hole 6, and thus, the heat exchange efficiency can be improved.

Here, the arithmetic mean roughness values Ra1 to R4 described above may be found by measurement using a contact-type surface roughness gauge in accordance with JIS B 0601 (2013). Examples of measurement conditions include, for example, a measurement length of 2.5 mm, a cutoff value of 0.8 mm, and a stylus scanning speed set to 0.3 mm/sec. In the following descriptions, items related to the discharge channel 9 will be described in parenthesis. Then, of the inner face of the second member 3 (third member 4) and the inner face of the introduction hole 5 (discharge hole 6), a section near adjacent positions may be defined as a measurement location, and the arithmetic mean roughness values Ra1 (Ra3) and Ra2 (Ra4) may be found by measuring at least three locations each in a direction along the direction in which the first fluid flows, and calculating the average value thereof

Further, a ratio Ra2/Ra1 (Ra4/Ra3) of the arithmetic mean roughness Ra1 (Ra3) to the arithmetic mean roughness Ra2 (Ra4) is preferably from 3 to 30, both inclusive. When Ra2/Ra1 (Ra4/Ra3) is from 3 to 30, both inclusive, significant turbulence in the first fluid can be generated without decreasing the speed in which the first fluid flows, and thus further improve the heat exchange efficiency.

Next, an example of a manufacturing method of the heat exchanger according to the embodiment will be described.

First, for the first member, for example, a slurry is manufactured by adding and mixing together a sintering aid, a binder, a solvent, a dispersing agent, and the like with a powder formed from primary component raw materials (silicon carbide, alumina, and the like), as appropriate. Then, using this slurry, a ceramic green sheet is formed by a doctor blade method.

Note that examples of other methods for forming the ceramic green sheet include manufacturing granules by spray drying and granulating the slurry by a spray drying and granulating method (spray drying method), and molding the obtained granules by roll compaction. Further, the ceramic green sheet may also be obtained by a mechanical pressing method and a cold isostatic pressing (CIP) method using the granules, or by manufacturing a green body rather than a slurry and using an extrusion molding method.

Next, the obtained ceramic green sheet is machined into a preferred profile shape using a metal mold or a laser beam, and machining for forming the introduction hole and the discharge hole is performed. The slurry is then applied to each ceramic green sheet, the sheets are laminated and pressurized, and the laminated and pressurized sheets are fired at a firing temperature in accordance with the primary component raw materials.

Here, to make, in a pair of adjacent introduction holes, a region that overlaps with the opening region of the upstream-side introduction hole, exist on the wall that includes the downstream-side introduction hole when viewed in the direction in which the first fluid flows, the downstream-side introduction hole may be formed so that the region that overlaps with the opening region of the upstream-side introduction hole remains on the ceramic green sheet when viewing the ceramic green sheet for forming the downstream-side introduction hole overlapped with the ceramic green sheet that formed the upstream-side introduction hole.

Specifically, given that the opening shapes are identical, the downstream-side introduction hole may be provided so as to differ in position from an outer edge of the ceramic green sheet. Or, the positions of each hole from the outer edge of the ceramic green sheet may be made identical and the opening shapes may be made different. Further, to make, in adjacent discharge holes, a region that overlaps with the opening region of the upstream-side discharge hole, exist on the wall that includes the downstream-side discharge hole when viewed in the direction in which the first fluid flows, the same method as described above may be used by replacing “introduction hole” with “discharge hole” and thus a description thereof is omitted.

Further, to make at least one of the plurality of first members include a chamfered area on the center section of the at least one of the plurality of the first members, on an edge of the introduction hole or discharge hole positioned on the downstream side of the first fluid, the edge being on the interior side of the at least one of the plurality of the first members, a shape of a blade of a metal mold that comes into contact with the applicable edge may be tapered or an angle of incidence of the laser beam may be adjusted during formation of the introduction hole or the discharge hole in the ceramic green sheet described above. Or, after formation of the introduction hole or the discharge hole, a pyramid shaped jig may be pressed and pushed against the applicable edge, or the edge may be chamfered by cut processing, for example.

Further, to make at least one of the plurality of first members include a protruding area at a position on the center section of the at least one of the plurality of the first members, in an area around the edge of the introduction hole or discharge hole positioned on the downstream side of the first fluid, the edge being on the interior side of the at least one of the plurality of the first members, the protruding area can be formed in the area around the applicable edge by adjusting the clearance between the used blade of the metal mold and mortar when the introduction hole or the discharge hole in the ceramic green sheet described above is press-formed by the metal mold. Further, after the introduction hole or the discharge hole has been provided to the ceramic green sheet, a protruding area can be formed by applying a paste having the same composition as that used for formation of the ceramic green sheet to the area around the applicable edge. Furthermore, at least one portion of the applicable edge of the ceramic green sheet may be made to protrude by pressing the area with a jig or the like.

Next, for the second member, the third member, and the flange portion, a slurry is manufactured by adding and mixing together a sintering aid, a binder, a solvent, a dispersing agent, and the like with a powder formed from primary component raw materials (silicon carbide, alumina, and the like) that constitute each of the members, as appropriate. Then, the second member, the third member, and the flange portion can be obtained by manufacturing granules by spray drying and granulating this slurry by a spray drying and granulating method, manufacturing a powder compact having a preferred shape by a mechanical pressing method or a cold isostatic pressing method using the obtained granules, cutting the powder compact as necessary, and firing. Note that grinding may be performed as necessary after firing.

Further, the powder compact of which the second member and the third member are made may be obtained by an extrusion molding method using a green body rather than the slurry. Further, the powder compact of which the flange portion is made may be formed by laminating the ceramic green sheets in the same way as with the first member.

Further, to make the arithmetic mean roughness Ra2 of the inner face of the introduction hole on the downstream side of the first fluid adjacent to the second member greater than the arithmetic mean roughness Ra1 of the inner face of the second member, a method such as follows may be used. For example, the arithmetic mean roughness Ra1 of the inner face of the second member is measured. Then, to ensure that the arithmetic mean roughness Ra2 of the inner face of the introduction hole on the downstream side of the first fluid adjacent to the second member is greater than the arithmetic mean roughness Ra1, the introduction hole is provided to the ceramic green sheet using an output-adjusted laser beam, the mold is pressed after the introduction hole is provided to the ceramic green sheet, or laser processing or blasting may be performed after firing is performed.

Further, to make the arithmetic mean roughness Ra4 of the discharge hole on the downstream side of the first fluid adjacent to the third member greater than the arithmetic mean roughness Ra3 of the inner face of the third member, the same method as described above may be used by replacing “second member” with “third member” and “introduction hole” with “discharge hole”. Thus, a description thereof is omitted.

Then, the heat exchanger can be obtained by using the obtained first member, second member, third member, and flange portion, applying an adhesive to the bonded parts of each member, disposing each member so that the first fluid communicates therethrough, and curing the adhesive by thermal treatment. Note that while the above has described shifting the positions of the holes to be formed or making the shapes of the holes to be formed different as a way to ensure that, in the introduction holes adjacent to the second member and the discharge holes adjacent to the third member, regions that overlap with opening regions of the upstream-side introduction holes (upstream-side discharge holes) exist in the walls including the downstream-side introduction holes (downstream-side discharge holes), when viewed in the direction in which the first fluid flows, the hole positions and the hole shapes may be made identical and the first member adjacent to the second member or the third member may be bonded in shifted position.

Further, when the number of first members is to be increased in the heat exchanger, the second member and the third member are preferably prepared and bonded in accordance with the number of first members.

Further, when the number of first members has been increased, the weight of each member of the upper level is applied to the areas around the introduction hole and the discharge hole of the first member of the lower level, and therefore the second member and the third member disposed between the first members may each be disposed so that a central axis thereof is shifted in the direction in which the first fluid flows. This makes it possible to decrease the possibility of the occurrence of flaws and cracks in the areas near the introduction hole and the discharge hole of the first member of the lower level caused by the applied weight of each member of the upper level.

Note that the preferred adhesive used is an inorganic adhesive superior in thermal resistance and corrosion resistance. Examples of such an inorganic adhesive include a paste that contains an SiO₂—Al₂O₃—B₂O₃—RO glass (R: alkaline earth metal element) powder and a powder obtained by mixing a silicon metal powder and a silicon carbide powder. When such a paste is used as the inorganic adhesive, the members can be strongly bonded together without deteriorating the members when thermal treatment is performed, and superior thermal resistance and corrosion resistance are achieved, and thus, the reliability of the heat exchanger can be improved.

The present invention has been described in detail above. However, the present invention is not limited to the embodiments described above, and various modifications or improvements can be made without departing from the essential spirit of the present invention.

Further, the heat exchanger described above is not particularly limited in application as long as heat exchange is performed, allowing suitable use as a heat exchanger for various laser devices, semiconductor elements, and semiconductor manufacturing devices, for example.

REFERENCE SIGNS LIST

• 1 Heat exchanger
• 2 First member
• 3 Second member
• 4 Third member
• 5 Introduction hole
• 6 Discharge hole
• 7 Introduction channel
• 8 First channel
• 9 Discharge channel
• 10 Second channel
• 11 Introduction portion
• 12 Discharge portion
• 13 Wall including introduction hole and discharge hole
• 14 Chamfered portion
• 15 Protruding portion
• 16 Flange portion

Claims

1. A heat exchanger that is formed from a ceramic and performs heat exchange between a first fluid and a second fluid, the heat exchanger comprising: a plurality of first members comprising walls that have introduction holes on a first end side and discharge holes on a second end side, with spaces connecting the introduction holes and the discharge holes serving as first channels through which the first fluid flows;an introduction channel comprising second members that communicate with the introduction holes at the first end side of the plurality of first members to introduce the first fluid into the first members; anda discharge channel comprising third members that communicate with the discharge holes at the second end side of the plurality of first members to discharge the first fluid that has flowed in the first members;spaces between the plurality of first members serving as second channels through which the second fluid flows; andwherein, in at least one adjacent pair of the introduction holes, a region of a wall forming a downstream-side introduction hole of the at least one adjacent pair overlaps with an opening region of an upstream-side introduction hole of the at least one adjacent pair in a direction in which the first fluid flows.

2. A heat exchanger that is formed from a ceramic and performs heat exchange between a first fluid and a second fluid, the heat exchanger comprising: a plurality of first members comprising walls that have introduction holes on a first end side and discharge holes on a second end side, with spaces connecting the introduction holes and the discharge holes serving as first channels through which the first fluid flows;an introduction channel comprising second members that communicate with the introduction holes at the first end side of the plurality of first members to introduce the first fluid into the first members; anda discharge channel comprising third members that communicate with the discharge holes at the second end side of the plurality of first members to discharge the first fluid that has flowed in the first members;spaces between the plurality of first members serving as second channels through which the second fluid flows; andwherein, in at least one adjacent pair of the discharge holes, a region of a wall forming a downstream-side discharge hole of the at least one adjacent pair overlaps with an opening region of an upstream-side discharge hole of the at least one adjacent pair in a direction in which the first fluid flows.

3. The heat exchanger according to claim 1, wherein the at least one of the plurality of first members includes a chamfered area in a side of a center section, on an interior edge of the downstream-side introduction hole, and wherein the center section is between the introduction hole and the discharge hole of the at least one of the plurality of first members.

4. The heat exchanger according to claim 1, wherein the at least one of the plurality of first members includes a protruding area between the downstream-side introduction hole and an upstream-side discharge hole of the at least one of the plurality of first members, around an interior edge of the downstream-side introduction hole.

5. The heat exchanger according to claim 1, wherein an arithmetic mean roughness Ra2 of an inner face of each of the introduction holes adjacent to a downstream side of the second members is greater than an arithmetic mean roughness Ra1 of an inner face of the one of the second members.

6. The heat exchanger according to claim 1, wherein an arithmetic mean roughness Ra4 of an inner face of each of the discharge holes adjacent to a downstream side of the third members is greater than an arithmetic mean roughness Ra3 of an inner face of the one of the third members.

7. The heat exchanger according to claim 2, wherein the at least one of the plurality of first members includes a chamfered area in a side of a center section, on an interior edge of the downstream-side discharge hole, and wherein the center section is between the introduction hole and the discharge hole of the at least one of the plurality of the first members.

8. The heat exchanger according to claim 2, wherein the at least one of the plurality of first members includes a protruding area on a center section of the at least one of the plurality of first members, around an interior edge of the downstream-side discharge hole, and wherein the center section is the downstream-side discharge hole and an upstream-side introduction hole.

9. The heat exchanger according to claim 2, wherein an arithmetic mean roughness Ra2 of an inner face of each of the introduction holes adjacent to a downstream side of the second members is greater than an arithmetic mean roughness Ra1 of an inner face of the one of the second members.

10. The heat exchanger according to claim 2, wherein an arithmetic mean roughness Ra4 of an inner face of each of the discharge holes adjacent to a downstream side of the third members is greater than an arithmetic mean roughness Ra3 of an inner face of the one of the third members.