JP4392218B2 - Multi-plate heat exchanger - Google Patents

Description

  The present invention relates to a heat exchange between a gas and a gas, for example, a multi-plate heat exchanger used to heat a heated fluid such as a fuel gas by using a heated fluid such as high-temperature exhaust gas.

As a multi-plate heat exchanger, for example, the one shown in FIG. 5 is known. The multi-plate heat exchanger 1 is composed of a plurality of flat heat exchange elements 3... 3 that are stacked with a predetermined gap G and have heat exchange fins 2 (see FIGS. 6 and 7 ) inside . The supply side communication port 4 communicating with one end side of the adjacent elements 3, 3, the supply port portion 6 for supplying the heated fluid 5 to the supply side communication port 4, and the adjacent elements 3, 3 A discharge side communication port 7 that communicates with the other end side, and a discharge port portion 8 that communicates with the discharge side communication port 7 and discharges the fluid 5 to be heated to the outside of the element 3, The heated fluid 5 supplied from the supply port 6 to the elements 3 to 3 through the supply side communication port 4 is heated with a high-temperature heating fluid such as exhaust gas flowing through the gap G and the like, and the exhaust What discharged | emitted from the exit part 8 is known. The element 3 is configured by abutting the peripheral wall portions 13 of the pair of substantially rectangular plates 11 and 12 and joining them together by brazing or the like.

  The plates 11 and 12 are provided with a cylindrical protrusion 14 constituting the supply side communication port 4, a cylindrical protrusion 15 constituting the discharge side communication part 7, and a number of embossed protrusions 16. It is formed as a single piece.

  Then, the cylindrical projections 14 of the plates 11 and 12 of the elements 3 adjacent to each other, the cylindrical projections 15, and a large number of embossed projections 16 are abutted with each other, and both are joined by brazing or the like. Thus, the elements are connected to each other.

  In the multi-plate heat exchanger, the plurality of elements 3... 3 are stacked in multiple stages, so that the heated fluid 5 supplied from the supply port 6 has a slow flow rate and a low flow rate. 3, the heated fluid 5 may not be supplied evenly. For this reason, even when the flow rate of the heated fluid 5 is slow and the flow rate is small, the multi-plate heat exchanger is provided with a flow rate adjusting unit 21 in order to supply the heated fluid 5 evenly to the elements 3. ing.

FIG. 6 shows an example of the element 3 having the flow rate adjusting part 21 of the conventional multi-plate heat exchanger. The flow rate adjusting unit 21 is provided with an orifice 23 at the center in the width direction (vertical direction in the drawing of FIG. 6) of the partition wall 22 provided between the supply side communication port 4 of the element 3 and the heat exchange fin 2 . Is formed.

As shown in FIG. 7 , the heat exchange fin 2 is formed in a width W and a height H by, for example, bending a metal plate into a corrugated plate shape, and is mounted in the flat element 3.

However, the conventional flow rate regulating unit 21, to have been formed by providing the orifice 23 in the center in the width direction of the partition wall 22, as indicated by a curve C to the flow velocity (flow rate) distribution characteristic diagram of FIG. 8, flow of heated fluid 5, the central portion in the width direction of the partition wall 22, i.e. the central portion in the width direction of the heat exchanging fin 2 concentrated on (part of POINT2 in FIG. 8), the width direction of the heat exchanging fins 2 both ends velocity of the heated fluid 5 in (part of POINT1 and POINT3 in FIG. 8) (flow rate) is, has a drawback that can not be utilized effectively throughout the extremely slow (less) becomes heat exchange fins 2 .

Therefore, in order to solve the above-described drawbacks, there has been developed a technique in which the number of holes is increased toward the downstream and the flow rate adjusting portion is formed by first to third perforated plates having a reduced hole diameter (for example, Patent Document 1). ).
JP-A-11-43305 (paragraph 0013, paragraph 0015, FIG. 7 etc.)

  By the way, in the conventional multi-plate heat exchanger, the flow rate adjustment is performed in order to form the first to third perforated plates having a smaller hole diameter while gradually increasing the number of holes as the flow rate adjustment unit goes downstream. There is a problem that the structure of the part becomes complicated and the flow resistance increases.

  An object of the present invention is to provide a multi-plate heat exchanger having excellent heat exchange efficiency while simplifying the structure of the flow rate adjusting unit.

The multi-plate heat exchanger according to the present invention is composed of a plurality of flat heat exchange elements which are arranged in a stack with a predetermined gap and have heat exchange fins inside, and supply one end side of adjacent elements. A side communication port, a supply port for supplying fluid to the supply side communication port, a discharge side communication port communicating with the other end of the adjacent element, and a heat exchange fin communicating with the discharge side communication port. A multi-plate type heat provided with a discharge port for discharging the heat exchanged fluid to the outside of the element, and a flow rate adjusting unit provided between the supply side communication port of each element and the heat exchange fin An exchanger,
The flow rate adjusting unit is provided between the supply side communication port and the heat exchange fin, and has a single orifice that narrows the passage width at the center in the width direction of the heat exchange fin , and the wake of the orifice The passage height is reduced in the height direction of the heat exchange fin to form a slit-like gap, and the fluid that has passed through the orifice is spread over the entire width direction of the heat exchange fin. And a fluid dispersion wall that is dispersed throughout.

The slit-shaped gap is formed as extending in the width direction of the heat exchange fin.

That is, the fluid to be heated that has flowed in from the supply-side communication port flows into the orifice of the flow rate adjusting unit, and then is provided further downstream by a fluid dispersion wall that restricts the passage height to a slit-like gap. The heat exchange fins are dispersed over the entire region in the width direction, are heat exchanged, and flow out from the discharge side communication port. Therefore, the fluid to be heated does not concentrate on a part in the width direction of the heat exchange fin.

According to the first aspect of the invention, the fluid supplied into the element from the communication portion on the supply side is squeezed by the orifice and then dispersed by the fluid dispersion wall, so that it is substantially uniform in the width direction of the heat exchange fin. To be supplied. Therefore, it is possible to provide a multi-plate heat exchanger with excellent heat exchange efficiency while simplifying the structure of the flow rate adjusting unit.

As shown in FIG. 5, the multi-plate heat exchanger 1 has a plurality of flat heat exchangers that are arranged in layers with a predetermined gap G and have heat exchange fins 2 (see FIGS. 1 and 7) inside. The supply side communication port 4 that is composed of the elements 3... And communicates with one end side of the adjacent elements 3 and 3, and the supply port portion 6 that supplies the heated fluid 5 to the supply side communication port 4. A discharge side communication port 7 communicating with the other end side of the elements 3, 3 to be discharged, and a discharge port portion 8 communicating with the discharge side communication port 7 for discharging the heated fluid 5 to the outside of the element 3. , And a high-temperature heating fluid such as exhaust gas is allowed to flow through the gap G. And the to-be-heated fluid 5 supplied to each element 3 ... 3 via the supply side communication port 4 from the said supply port part 6 is heated by the said heat exchange fin 2, etc., and is discharged | emitted from the discharge port part 8. FIG. It is like that.

The element 3 includes a pair of substantially rectangular plates 11 and 12, a cylindrical protrusion 14 that constitutes the supply side communication port 4, and a cylindrical protrusion 15 that constitutes the discharge side communication port 7. A number of embossed protrusions 16 and the peripheral wall portion 13 are integrally formed to project.

Further, the element 3 will be described in detail. As shown in FIG. 1, the heat exchange fin 2 is placed in the vicinity of the discharge side communication port 7, and between the supply side communication port 4 and the heat exchange fin 2. Is provided with a flow rate adjusting unit 21. The flow rate adjusting unit 21 is provided on the downstream side of the orifice 23 formed in a substantially central portion in the width direction of the partition wall 22 provided in the pair of plates 11 and 12 constituting the element 3. And a fluid dispersion wall 24 for flowing the fluid 5 to be heated in a substantially uniform manner over the entire region in the width direction of the heat exchange fin 2.

As shown in FIGS. 2 and 3, the fluid dispersion wall 24 includes a pair of plates 11, 12 constituting the element 3 between the rib-like protrusions 25, 26 with the opposing portions protruding to the inner surface side. 3 is formed by providing streak-like gaps (slits) 27 extending in the width direction.

Then, the cylindrical projections 14 of the plates 11 and 12 of the elements 3 adjacent to each other, the cylindrical projections 15, the numerous embossed projections 16, the peripheral wall 13 and the flow rate adjustment unit 21 are mutually connected. The elements are connected to each other by joining them together by brazing or the like. When the plates 11 and 12 are joined by brazing or the like, the embossed protrusions 16 do not have to be joined together.

  The multi-plate heat exchanger 1 according to the embodiment has the above-described configuration, and as shown in FIG. 1, the objects to be supplied to the elements 3... 3 through the supply port 6 and the supply side communication port 4. The heated fluid 5 first passes through the orifice 23. As shown in FIG. 2, the heated fluid 5 that has passed through the orifice 23 hits the inclined walls 25 a and 26 a on the upstream side of the rib-like protrusions 25 and 26 of the fluid dispersion wall 24 and converges on the protrusions 25 and 26. It flows into the formed streaky gap (slit) 27. The streak-like gap 27 is formed so as to extend across the entire width direction of the heat exchange fin 2 in the width direction of the element 3. After being sufficiently diffused, the heated fluid 5 is dispersed in the width direction of the heat exchange fins 2.

Here, in the graph of FIG. 8, the horizontal axis indicates the outer measurement point POINT1 that is substantially bisected in the longitudinal direction of the heat exchange fin placed in the element 3 and is substantially perpendicular to the flow direction. The measurement points POINT2 and POINT3 on the opposite side to the POINT1 are shown, and the vertical axis shows the flow velocity of the fluid flowing through the measurement points. Therefore, as shown by the curve A in the flow velocity (flow rate) distribution diagram of FIG. 8, not only the central portion in the width direction of the heat exchange fin 2 but also the left and right end portions in the width direction of the heat exchange fin 2 are heated. It can be seen that the fluid is sufficiently diffused and flowing.

Further, as shown in FIG. 4, if the distance L from the fluid dispersion wall 24 to the heat exchange fin 2 is increased, the heat exchange fin is shown in the flow velocity (flow rate) distribution characteristic diagram of FIG. 2, it can be seen that the averaged fluid to be heated circulates in the heat exchange fins 2.

The front view of the plate which comprises an element. AA sectional drawing of FIG. BB sectional drawing of FIG. The front view of the plate which comprises the element of another Example. The top view of a multi-plate heat exchanger. The front view of the plate which comprises the element of the conventional multi-plate type heat exchanger. The perspective view of the fin for heat exchange. The flow velocity (flow rate) distribution characteristic view of the fluid to be heated.

1 ... Multi-plate heat exchanger
2 ... Fins for heat exchange
3 ... Element 4 ... Supply side communication port
5 ... Heated fluid
6 ... Supply port
7 ... Discharge side communication port
8 ... Discharge port
11, 12 ... Plate
21 ... Flow rate adjuster
22 ... Bulkhead
23: Orifice
24 ... Fluid dispersion wall
25, 26 ... projections
27 ... Gap

Claims (1)

It consists of a plurality of flat heat exchange elements that are arranged in layers with a predetermined gap and have heat exchange fins inside.
A supply-side communication port communicating with one end side of an adjacent element;
A supply port for supplying fluid to the supply side communication port;
A discharge side communication port communicating with the other end side of the adjacent element;
A discharge port for discharging the fluid exchanged with the heat exchange fins and communicating with the discharge side communication port to the outside of the element;
A flow rate adjusting unit provided between the supply side communication port of each element and the heat exchange fin;
In the multi-plate heat exchanger provided with
The flow rate adjustment unit
A single orifice provided between the supply side communication port and the heat exchange fin, and narrowing the passage width to the center in the width direction of the heat exchange fin ;
Provided on the downstream side of the orifice, the passage height is narrowed in the height direction of the heat exchange fin to form a slit-like gap, and the fluid that has passed through the orifice is allowed to flow through the heat exchange fin. A fluid dispersion wall that is dispersed over the entire width direction;
A multi-plate heat exchanger characterized by comprising:

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