JP3697523B2 - Regenerative heat exchanger and regenerative heat exchange method - Google Patents

Description

  The present invention relates to a regenerative heat exchanger and a regenerative heat exchange method that can be suitably used for energy systems such as air conditioners, refrigerators, gas turbines, and fuel cells.

  In a conventional regenerative heat exchanger, a primary surface type heat exchanger configured with a flow path having a rectangular shape such as a rectangle by overlapping partition walls (members) bent in a wave shape, and a parallel plate partition wall. An inner fin type heat exchanger with a corrugated fin corrugated is used frequently. In these heat exchangers, for the purpose of improving the performance and downsizing, the hydraulic diameter that has a great influence on the heat transfer performance has been reduced by reducing the pitch of the heat transfer surface bent in a wave shape.

  In the above-described conventional regenerative heat exchanger, when heat recovery is performed from high-temperature exhaust gas discharged from a gas turbine or the like or exhaust gas containing corrosive components, a partition wall or inner wall is used from the viewpoint of the reliability of the regenerative heat exchanger. A certain thickness is required for the thickness of the fin.

  However, it is very difficult to produce a thick partition wall or inner fin by subjecting a thick plate to a bending process using a press, and the flow path can be increased by increasing the thickness of the partition wall. Problems such as a decrease in cross-sectional area and an increase in pressure loss also occur. Furthermore, by increasing the thickness of the partition wall or the like, it is also possible to apply heat transfer enhancement technology due to the leading edge effect such as slits performed by fins of air conditioners. It was difficult due to problems such as corrosion from the cut part.

  As a result, in the conventional regenerative heat exchanger, there is a limit to the improvement of the heat transfer performance, and it is difficult to further reduce the size.

  It is an object of the present invention to provide a regenerative heat exchanger that maintains reliability such as heat resistance and corrosion resistance and has a high heat transfer promoting function and can be made sufficiently compact. A further object of the present invention is to provide a regenerative heat exchange method using the regenerative heat exchanger.

In order to achieve the above object, the present invention provides:
A plurality of rectangular members adjacent to each other for flowing a plurality of fluids having different temperatures, and a flow direction of the fluid on at least one inner surface portion of each of the plurality of rectangular members in contact with the fluid and a plurality of concave-convex ribs to form a predetermined angle,
The present invention relates to a regenerative heat exchanger characterized in that an angle between the plurality of concave and convex ribs and the flow direction of the fluid is 30 to 80 degrees .

  According to the regenerative heat exchanger of the present invention, the flow of the fluid to at least one inner surface portion of the plurality of rectangular members adjacent to each other for flowing a plurality of fluids having different temperatures for heat exchange, that is, the partition wall portion. A plurality of concave and convex ribs are provided so as to form a predetermined angle with the direction. At this time, when the fluid comes into contact with the partition wall, a secondary flow component, that is, a vertical vortex is generated in the cross section of the flow path to generate a swirling flow. This swirl flow facilitates mixing of the fluid heat-exchanged component in the vicinity of the partition wall and the main-flow component of the fluid that flows through the substantially central portion of the rectangular member, so that extremely high heat transfer performance is achieved. It will be obtained.

  Furthermore, since the velocity of the fluid in the vicinity of the partition increases, heat transferred from the partition can be efficiently propagated through the convection of the fluid, and the heat transfer performance can be further improved.

  Further, the swirling flow is not accelerated or disturbed by the separation from the partition wall, so that no large pressure loss occurs.

  Furthermore, since the concave and convex ribs can be easily formed by press working, reliability is not reduced due to local thinning or exposure of the cut surface.

  Therefore, according to the present invention, it is possible to obtain a regenerative heat exchanger that maintains reliability such as heat resistance and corrosion resistance, has a high heat transfer promoting function, and can be made sufficiently compact.

  In a preferred embodiment of the present invention, the plurality of concave and convex ribs intersect each other on the inner side surface. Furthermore, on the inner side surface, the angle of the angle intersects with the fluid flow direction so as to alternate. In this case, it is possible to generate swirl flows having different rotation directions on the same inner surface on which the plurality of concave and convex ribs are formed, that is, on the partition walls, and to further improve the heat transfer performance described above. .

Moreover, in this invention, the angle which the said some uneven | corrugated rib makes with the said fluid flow direction shall be 30 to 80 degree | times. If the angle is smaller than 30 degrees, sufficient heat transfer performance by generating swirl flow cannot be realized. On the other hand, if the angle is larger than 80 degrees, the pressure loss increases and a large flow loss occurs, and the heat transfer performance described above cannot be generated.

  Furthermore, in another preferable aspect of the present invention, the pitch of the plurality of concave and convex ribs is equal to or shorter than the length of the short side in the cross section of the rectangular member. If the pitch exceeds the length of the short side, the swirl flow cannot be generated by the concave and convex ribs, and sufficient heat transfer performance may not be generated.

In addition, this invention relates to the regeneration heat exchange method using the regeneration heat exchanger mentioned above,
A step of configuring a regenerative heat exchanger by combining a plurality of rectangular members adjacent to each other;
Providing a plurality of concave and convex ribs on at least one inner surface portion of each of the plurality of rectangular members in contact with the fluid so as to form a predetermined angle with the flow direction of the fluid;
Flowing a plurality of fluids having different temperatures through the plurality of rectangular members, and performing heat exchange through a partition wall between the adjacent rectangular members ,
An angle between the plurality of concave and convex ribs and the fluid flow direction is 30 degrees to 80 degrees .
Other features and advantages of the present invention are described in detail below.

Hereinafter, the present invention will be described in detail based on embodiments of the invention.
FIG. 1 is a block diagram showing an example of a regenerative heat exchanger according to the present invention. In FIG. 1, a primary surface type regenerative heat exchanger 10 is configured by combining a plurality of rectangular members 11 bent in a wave shape so as to be adjacent to each other while forming a step. The inside of the rectangular member 11 is hollow and constitutes a flow path through which the fluid propagates. A plurality of concavo-convex ribs 12 are formed on the inner surface 11A of each rectangular member 11, that is, on the partition wall 11A for the flow paths adjacent to each other.

  When fluids having different temperatures flow through the rectangular member 11 of the regenerative heat exchanger 10 shown in FIG. 1, these fluids exchange heat with each other through the partition wall 11A, and as a result, heat exchange is performed. At this time, when the fluid comes into contact with the partition wall 11A, a secondary flow component, that is, a vertical vortex is generated in the cross section of the flow path to generate a swirling flow. This swirl flow promotes mixing of the fluid heat-exchanged component in the vicinity of the partition wall 11 </ b> A and the main-flow component of the fluid flowing through the substantially central portion of the rectangular member 11, so that extremely high heat transfer performance is achieved. It will be obtained.

  Further, since the velocity of the fluid in the vicinity of the partition wall 11A increases, the heat transferred from the partition wall 11A can be efficiently propagated through the convection of the fluid, and the heat transfer performance can be further improved. Further, the swirling flow is not accelerated or disturbed by the separation from the partition wall, so that no large pressure loss occurs. Furthermore, since the concave and convex ribs can be easily formed by press working, reliability is not reduced due to local thinning or exposure of the cut surface.

  Accordingly, the regenerative heat exchanger 10 shown in FIG. 1 maintains reliability such as heat resistance and corrosion resistance and has a high heat transfer promoting function, and can be made sufficiently compact.

In addition, the angle θ between the plurality of concave and convex ribs 12 and the fluid flow direction indicated by the arrows in the drawing is 30 to 80 degrees. If the angle θ is smaller than 30 degrees, sufficient heat transfer performance due to swirl flow generation cannot be realized. On the other hand, if the angle θ is greater than 80 degrees, the pressure loss increases and a large flow loss occurs, so that the heat transfer performance described above cannot be generated.

  Further, the pitch P of the plurality of concave and convex ribs 12 is preferably equal to or shorter than the length L of the short side in the cross section of the rectangular member 12. If the pitch P increases beyond the length L of the short side, the swirl flow cannot be generated by the uneven rib 12, and sufficient heat transfer performance may not be generated.

  In addition, the magnitude | size, length, etc. of the cross section of the rectangular member 11 which comprises the regenerative heat exchanger 10 can be suitably set according to the degree of heat exchange and its use.

  FIG. 2 is a configuration diagram showing another example of the regenerative heat exchanger of the present invention. In FIG. 2, a plurality of rectangular members 21 bent in a wave shape are combined so as to be adjacent to each other and sandwiched between flat plates 25 to constitute an inner fin type regenerative heat exchanger 20. The inside of the rectangular member 21 is hollow and constitutes a flow path through which the fluid propagates. A plurality of concavo-convex ribs 22 are formed on the inner surface 21A of each rectangular member 21, that is, on the partition wall 21A for the flow paths adjacent to each other.

  When fluids having different temperatures flow through the rectangular member 21 of the regenerative heat exchanger 20 shown in FIG. 2, these fluids exchange heat with each other through the partition wall 21A, and as a result, heat exchange is performed. At this time, when the fluid comes into contact with the partition wall 21A, a secondary flow component, that is, a vertical vortex is generated in the cross section of the flow path to generate a swirling flow. This swirl flow promotes mixing of the fluid heat-exchanged component in the vicinity of the partition wall 21A and the main-stream component of the fluid that flows through the substantially central portion of the rectangular member 21, so that extremely high heat transfer performance is achieved. It will be obtained.

  Further, since the fluid velocity in the vicinity of the partition wall 21A increases, the heat transferred from the partition wall 21A can be efficiently propagated through the convection of the fluid, and the heat transfer performance can be further improved. Further, the swirling flow is not accelerated or disturbed by the separation from the partition wall, so that no large pressure loss occurs. Furthermore, since the concave and convex ribs can be easily formed by press working, reliability is not reduced due to local thinning or exposure of the cut surface.

  Therefore, the regenerative heat exchanger 20 shown in FIG. 2 maintains reliability such as heat resistance and corrosion resistance and has a high heat transfer promoting function, and can be made sufficiently compact.

The angle ψ between the plurality of concave and convex ribs 22 and the fluid flow direction indicated by the arrows in the figure is 30 to 80 degrees. If the angle ψ is smaller than 30 degrees, sufficient heat transfer performance due to swirl flow generation cannot be realized. On the other hand, when the angle ψ is larger than 80 degrees, the pressure loss increases and a large flow loss occurs, so that the heat transfer performance described above cannot be generated.

  In addition, the pitch Q of the plurality of concave and convex ribs 22 is preferably equal to or shorter than the short side length R in the cross section of the rectangular member 21. If the pitch Q increases beyond the length R of the short side, the swirl flow cannot be generated by the concave and convex ribs 22 and sufficient heat transfer performance may not be generated.

  In addition, the magnitude | size of the cross section of the rectangular member 21 which comprises the regenerative heat exchanger 20, a length, etc. can be suitably set according to the degree of heat exchange and its use.

  FIG. 3 is a configuration diagram illustrating a modified example of the regenerative heat exchanger illustrated in FIG. 1. 3, similarly to FIG. 1, a primary surface type regenerative heat exchanger 30 is configured by combining a plurality of rectangular members 31 bent in a wave shape so as to be adjacent to each other while forming a step. Yes. The interior of the rectangular member 31 is hollow and constitutes a flow path through which the fluid propagates. Then, on the inner side surface 31A of each rectangular member 31, that is, on the side partition wall 31A with respect to the flow paths adjacent to each other, the fluid flows in the direction of the fluid so that the signs of the angles are different from each other, so A plurality of concave and convex ribs 32 are formed as described above.

  When fluids having different temperatures flow through the rectangular member 31 of the regenerative heat exchanger 30 shown in FIG. 3, these fluids exchange heat with each other through the partition wall 31A, and as a result, heat exchange is performed. At this time, when the fluid comes into contact with the partition wall 31A, secondary flow components in opposite directions, that is, longitudinal vortices are generated in the flow path cross section, and swirl flows in opposite directions are generated. That is, it is possible to generate swirl flows having different rotation directions on the same inner partition wall 31A, and the heat transfer performance described above can be further improved.

  Other characteristics required for the regenerative heat exchanger 30 shown in FIG. 3 are the same as those required for the regenerative heat exchanger 10 shown in FIG.

  As described above, the present invention has been described in detail based on the embodiments of the present invention with specific examples. However, the present invention is not limited to the above contents, and all modifications and changes are made without departing from the scope of the present invention. It can be changed.

  For example, in the above specific example, the pitch of the concavo-convex ribs is defined by comparison with the short side in the cross section of the rectangular member, but when the cross section of the rectangular member is a square, It can be defined by comparison.

  Further, in the regenerative heat exchanger shown in FIG. 3, the concavo-convex ribs are formed so as to intersect with each other so that the sign of the angle is different from the flow direction of the fluid, and the overall shape is formed into a V shape. It can also be formed.

It is a block diagram which shows an example of the regenerative heat exchanger of this invention. It is a block diagram which shows the other example of the regenerative heat exchanger of this invention. It is a block diagram which shows the modification of the regenerative heat exchanger shown in FIG.

Explanation of symbols

10, 20, 30 Regenerative heat converter 11, 21, 31 Rectangular member 11A, 21A, 31A Inner side surface (partition) of rectangular member
12, 22, 32 Uneven rib

Claims (14)

A plurality of rectangular members adjacent to each other for flowing a plurality of fluids having different temperatures, and a flow direction of the fluid on at least one inner surface portion of each of the plurality of rectangular members in contact with the fluid and a plurality of concave-convex ribs to form a predetermined angle,
The regenerative heat exchanger characterized in that an angle between the plurality of concave and convex ribs and the fluid flow direction is 30 degrees to 80 degrees .   The regenerative heat exchanger according to claim 1, wherein the plurality of concave and convex ribs intersect each other on the inner side surface.   3. The regenerative heat exchanger according to claim 2, wherein the plurality of concave and convex ribs intersect on the inner side surface such that the signs of the angles are different from each other with respect to the flow direction of the fluid. The regenerative heat exchanger according to any one of claims 1 to 3 , wherein a pitch of the plurality of concave and convex ribs is equal to or shorter than a length of a short side in a cross section of the rectangular member. The regenerative heat exchanger according to any one of claims 1 to 4 , wherein a swirl flow of the fluid is generated in a cross section of the flow path by the plurality of uneven ribs. The regenerative heat exchanger according to any one of claims 1 to 5 , wherein the heat exchanger is a primary surface type heat exchanger. The regenerative heat exchanger according to any one of claims 1 to 5 , wherein the heat exchanger is an inner fin type heat exchanger. A step of configuring a regenerative heat exchanger by combining a plurality of rectangular members adjacent to each other;
Providing a plurality of concave and convex ribs on at least one inner surface portion of each of the plurality of rectangular members in contact with the fluid so as to form a predetermined angle with the flow direction of the fluid;
Flowing a plurality of fluids having different temperatures through the plurality of rectangular members, and performing heat exchange through a partition wall between the adjacent rectangular members ,
The regenerative heat exchange method , wherein an angle formed by the plurality of concave and convex ribs with the fluid flow direction is 30 degrees to 80 degrees . The regenerative heat exchange method according to claim 8 , wherein the plurality of concave and convex ribs intersect each other on the inner side surface. The regenerative heat exchange method according to claim 9 , wherein the plurality of concave and convex ribs intersect on the inner side surface so that the signs of the angles are different from each other with respect to the fluid flow direction. The regenerative heat exchange method according to any one of claims 8 to 10 , wherein a pitch of the plurality of concave and convex ribs is set to be equal to or less than a length of a short side in a cross section of the rectangular member. The regenerative heat exchange method according to any one of claims 8 to 11 , wherein a swirl flow of the fluid is generated in a cross section of the flow path by the plurality of uneven ribs. The regenerative heat exchange method according to any one of claims 8 to 12 , wherein the regenerative heat exchanger constitutes a primary surface type heat exchanger. The regenerative heat exchanger method according to any one of claims 8 to 12 , wherein the regenerative heat exchanger constitutes an inner fin type heat exchanger.

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