JP2021071274A - Heat exchanger - Google Patents

Abstract

To provide a heat exchanger in which a pipe pitch in a flow direction of a fluid which is caused to flow to the outside of a heat transfer pipe, is shortened without closing a duct in the flow direction of the fluid which is caused to flow to the outside of the heat transfer pipe, due to an adhesive substance even in the case the adhesive substance is contained in the fluid which is caused to flow to the outside of the heat transfer pipe.SOLUTION: The present invention relates to a heat exchanger 1 comprising a plurality of heat transfer pipes 10. The heat transfer pipe 10 includes: a plurality of straight pipe parts 40 disposed in a matrix shape of M rows and N columns in a predetermined pipe pitch in a row direction along an exhaust gas flow direction and a column direction orthogonal with the row direction; one-side curved pipe part 50 connecting one end of the straight pipe part 40 in an m-th row and an n-th column with one end of a straight pipe part 40 in a (m+1)th row and a (n+1)th column in the plurality of straight pipe parts 40; and another-side curved pipe part 60 connecting the other end of the straight pipe part 40 in the (m+1)th row and the (n+1)th column with the other end of a straight pipe part 40 in a (m+2)th row and the n-th column in the plurality of straight pipe parts 40.SELECTED DRAWING: Figure 2

Description

The present invention relates to, for example, a heat exchanger incorporated in a boiler of a waste incineration facility.

This type of heat exchanger has multiple heat transfer tubes. Then, for example, water flows inside the heat transfer tube, exhaust gas from the incinerator flows outside the heat transfer tube, and heat exchange is performed between the water and the exhaust gas via the heat transfer tube.

FIG. 4 is an explanatory diagram of a conventional heat exchanger. As shown in FIGS. 4A and 4A, in the heat exchanger 100 having a grid-like heat transfer tube structure, the plurality of heat transfer tubes 101 are in a row direction along the exhaust gas flow direction and in the row direction. A plurality of straight pipe portions 102 are provided so as to be arranged in a matrix at predetermined pipe pitches in the orthogonal row directions. One ends of the straight pipe portions 102 adjacent to each other in the row direction are connected by a one-side curved pipe portion 103. The other ends of the straight pipe portions 102 adjacent to each other in the row direction are connected by the other side curved pipe portion 104. In addition to the merit of having a simple structure, such a grid-like arrangement has the merit that dust of adhesive substances contained in exhaust gas is less likely to be clogged between straight pipes adjacent to each other in the row direction. Therefore, it is generally used as a heat transfer tube structure for boilers.

Arrangements that can be made denser than the above-mentioned grid arrangement with respect to the heat transfer tube structure include staggered arrangements as shown in FIGS. 4 (b) and (b') and 4 (c) and (c') (for example). , Patent Documents 1 and 2). In the case of the staggered arrangement, the straight pipe portions 102 are connected to each other by the curved pipe portions 103 and 104 along the exhaust gas flow direction (FIG. 4B). (See (b')) and those connected by curved pipe portions 103 and 104 inclined obliquely with respect to the exhaust gas flow direction (see FIGS. 4 (c) and (c')).

As one of the means for shortening the pipe pitch in the exhaust gas flow direction, as shown in FIGS. 4 (d) and 4 (d'), a predetermined number of straight pipe portions 112 arranged in the exhaust gas flow direction have a radius of curvature. There is a method in which a plurality of curved pipe portions 113, 114, 115, which gradually increase in size, are connected together (see, for example, Patent Document 3).

Further, as another means for shortening the pipe pitch in the exhaust gas flow direction, as shown in FIGS. 4 (e) and 4 (e'), the ends of the straight pipe portions 122 arranged in the exhaust gas flow direction are connected to each other by a cylindrical header 123. (See, for example, Patent Document 4). The straight pipe portion 122 and the header 123 are joined by welding. In this case, it is possible to shorten the pipe pitch to the limit of the gap required for welding the two straight pipe portions 122 arranged in the exhaust gas flow direction with respect to the header 123.

Further, as shown in FIGS. 4 (f) and 4 (f'), a U-shaped cast header 133 may be used instead of the cylindrical header 123 (for example, Patent Document 5). See).

JP-A-2018-80852 Japanese Unexamined Patent Publication No. 9-26102 Japanese Unexamined Patent Publication No. 2001-147093 Japanese Unexamined Patent Publication No. 2000-18501 JP-A-2017-9265

In the ones shown in FIGS. 4A and 4A, the exhaust gas flow direction (row direction) is limited by the manufacturing minimum bending radius for each of the one-side curved pipe portion 103 and the other-side curved pipe portion 104. ), The pipe pitch of the straight pipe portion 102 is limited. For this reason, the heat exchanger arranged in a grid pattern has a drawback that it is difficult to shorten the pipe pitch of the straight pipe portion 102 in the exhaust gas flow direction, and it is difficult to make it compact.

The ones shown in FIGS. 4 (b) and (b') and 4 (c) and (c') can be made more compact than those shown in FIGS. 4 (a) and 4 (a'). However, when a plurality of straight pipe portions 102 are viewed in the exhaust gas flow direction, the straight pipe portions 102 in the next row are located between the straight pipe portions 102 adjacent to each other in the column direction in one row. Therefore, dust in the exhaust gas adheres and accumulates on the straight pipe portion 102 in the next row, and the space between the straight pipe portion 102 adjacent to each other in the column direction in one row and the straight pipe portion 102 in the next row becomes There is a problem that the heat exchange rate is deteriorated because the flow path in the exhaust gas flow direction is blocked by the grown dust.

In the ones shown in FIGS. 4 (d) and 4 (d'), the bending dimension of the outermost curved pipe portion 115 among the plurality of curved pipe portions 113, 114, 115 becomes extremely large to reduce the size. This becomes difficult, the dead space increases, and the pipe pitch of the straight pipe portion 112 in the exhaust gas flow direction cannot be shortened so much due to the limitation of the minimum bending radius of the innermost curved pipe portion 113.

In the ones shown in FIGS. 4 (e) and 4 (e'), the cylindrical header 123 must be processed separately, and it takes time and effort to weld the straight pipe portion 122 and the header 123. There is a problem of increased cost required for welding.

In the cases shown in FIGS. 4 (f) and 4 (f'), although it is possible to reduce the cost to some extent by adopting the cast header 133 in the case of mass production, the processing cost of the header 133 is still required for welding. The problem of increased costs cannot be solved.

The present invention has been made in view of the above problems, and even if the fluid flowing to the outside of the heat transfer tube contains an adhesive substance, the fluid flowing to the outside of the heat transfer tube due to the adhesive substance It is an object of the present invention to provide a heat exchanger capable of shortening the tube pitch in the flow direction of the fluid flowing to the outside of the heat transfer tube without causing blockage of the flow path in the flow direction.

The characteristic configuration of the heat exchanger according to the present invention for solving the above problems is
A plurality of heat transfer tubes are provided, and of two fluids having different temperatures, one fluid flows inside the heat transfer tube, the other fluid flows outside the heat transfer tube, and the two fluids pass through the heat transfer tube. A heat exchanger configured to exchange heat between fluids.
The heat transfer tube is
A matrix of M rows and N columns (M is an integer of 3 or more, N is an integer of 2 or more) at a predetermined pipe pitch in the row direction along the flow direction of the other fluid and in the column direction orthogonal to the row direction. With multiple main units located in
The main section of the mth row and nth column (m = 1, ..., M, n = 1, ..., N) and the main section of the (m + 1) th row and th column (n + 1) in the plurality of main sections. One side tube that connects one end of the
The other side pipe portion that connects the other ends of the main pipe portion of the (m + 1) row and th (n + 1) column and the main pipe portion of the (m + 2) row and nth column in the plurality of main pipe portions, and the other side pipe portion.
Is to include.

In the heat exchanger of this configuration, M rows and N columns (M is an integer of 3 or more, N is an integer of 3 or more, N is an integer of 3 or more, N is a row direction along the flow direction of the other fluid and a column direction orthogonal to the row direction at predetermined pipe pitches, respectively. A plurality of main parts are arranged in a matrix of 2 or more integers). According to such an arrangement, when a plurality of main parts are viewed in the flow direction of the other fluid, the main parts of the next row are not located between the main parts adjacent to each other in the column direction in one row. Therefore, even if the fluid flowing to the outside of the heat transfer tube contains an adhesive substance, the flow path in the flow direction of the fluid flowing to the outside of the heat transfer tube is not blocked due to the adhesive substance.

Further, in the heat exchanger having this configuration, one end of the main pipe portion in the mth row and nth column and the main pipe portion in the (m + 1) th row and (n + 1) column is connected by a one-side pipe portion. Since one side pipe does not connect one ends of the main pipes adjacent to each other in the row direction in the same column, the adjacent main pipes tentatively contact the pipe pitches of the main pipes adjacent to each other in the row direction in the same column. Even if it is made as small as possible, one ends of the main section of the mth row and nth column and the main section of the (m + 1) th row and th column (n + 1) can be connected to each other. Similarly, in the heat exchanger having this configuration, the other ends of the main pipe portion in the (m + 1) row and the (n + 1) column and the main pipe portion in the (m + 2) row and the nth column are connected by the other side pipe portion. Will be done. Since the other side pipes do not connect the other ends of the main pipes adjacent to each other in the row direction in the same column, the pipe pitches of the main pipes adjacent to each other in the row direction in the same column are assumed to be set by the adjacent main pipes. Even if the size is reduced until they come into contact with each other, the other ends of the main pipe portion in the (m + 1) th row and (n + 1) column and the main pipe portion in the (m + 2) th row and nth column can be connected to each other. Therefore, in theory, the pipe pitch in the flow direction (row direction) of the fluid flowing to the outside of the heat transfer tube can be shortened until the main pipes adjacent to each other in the row direction come into contact with each other, thereby making the heat exchanger compact. Can be planned.

In the heat exchanger according to the present invention
The main pipe portion has a shape extending linearly in a direction intersecting the flow direction of the other fluid, and both the one side pipe portion and the other side pipe portion have a shape curved with a predetermined bending radius. It is preferable to have.

According to the heat exchanger of this configuration, a main pipe portion having a shape extending linearly and one side having a shape curved with a predetermined bending radius by performing the required bending process on one long pipe. The heat transfer tube can be configured so that the tube portion and the other side tube portion are seamlessly continuous, and the header and the straight tube portion are joined by welding to form the heat transfer tube. Compared with those shown in e') and FIGS. 4 (f) and (f'), it is advantageous in terms of strength and the manufacturing cost can be kept low.

In the heat exchanger according to the present invention
When the pipe pitch in the row direction in the plurality of main pipe portions is P and the pipe outer diameter of the plurality of main pipe portions is D, it is preferable that the relationship of D ≦ P ≦ 2.5D is satisfied.

According to the heat exchanger of this configuration, the pipe pitch P in the row direction in the plurality of main pipe portions and the pipe outer diameter D of the plurality of main pipe portions satisfy the relationship of D≤P≤2.5D. Therefore, it is possible to make the heat exchanger 100 (see FIGS. 4A and 4A) more compact than the conventional heat exchanger 100 having a grid pattern arrangement with P = 3D. Further, by reducing P = D, that is, the pipe pitch in the row direction until the main pipe portions adjacent to each other in the row direction come into contact with each other in the same column, FIGS. 4 (b) and (b'), and FIGS. 4 (c) and ( It can be made much more compact than the staggered heat exchanger shown in c').

FIG. 1 shows a heat exchanger according to an embodiment of the present invention, (a) is an external perspective view seen from the front side, and (b) is an external perspective view seen from the back side. FIG. 2 is a schematic view showing a generalized front view arrangement of the heat exchanger according to the embodiment of the present invention. FIG. 3 is an external perspective view of a heat transfer tube constituting the heat exchanger according to the embodiment of the present invention. FIG. 4 is an explanatory diagram of a conventional heat exchanger.

Hereinafter, the present invention will be described with reference to FIGS. 1 to 3. In the following embodiment, a heat exchanger incorporated in a boiler of a waste incineration facility will be described as an example. However, the present invention is not intended to be limited to the configurations described in the embodiments and drawings described below.

<Overall configuration>
FIG. 1 shows a heat exchanger according to an embodiment of the present invention, (a) is an external perspective view seen from the front side, and (b) is an external perspective view seen from the back side. The heat exchanger 1 shown in FIGS. 1 (a) and 1 (b) includes a plurality of heat transfer tubes 10, a one-side support member 20 that supports one side (front side) of the plurality of heat transfer tubes 10, and a plurality of heat transfer tubes. It includes a other side support member 30 that supports the other side (back side) of the heat tube 10. Then, for example, water (corresponding to "one fluid" of the present invention) is allowed to flow inside the heat transfer tube 10, and exhaust gas from an incinerator (not shown) outside the heat transfer tube 10 (to the "other fluid" of the present invention). Correspondingly) is flowed from the upper side to the lower side in FIGS. 1A and 1B, and heat is exchanged between water having different temperatures and exhaust gas via a heat transfer tube 10, for example, for power generation. Produces steam.

In the present embodiment, a support structure for supporting a plurality of heat transfer tubes 10 by using a plate-shaped one-side support member 20 and another side support member 30 is illustrated, but the positions of the plurality of heat transfer tubes 10 are different from each other. It suffices if it can be fixed. For example, a pair of support plates are arranged so as to sandwich the plurality of straight pipe portions 40 from both sides, and these support plates are fastened by fastening means such as bolts to mutually support the plurality of heat transfer tubes 10. A support structure that fixes the position may be adopted.

The plurality of heat transfer tubes 10 correspond to a plurality of straight pipe portions 40 (corresponding to the "main pipe portion" of the present invention) and a plurality of one-side curved pipe portions 50 (corresponding to the "one-side pipe portion" of the present invention. ) And a plurality of other side curved pipe portions 60 (corresponding to the "other side pipe portion" of the present invention).

<Straight pipe>
FIG. 2 is a schematic view showing a generalized front view arrangement of the heat exchanger according to the embodiment of the present invention. As shown in the schematic diagram of FIG. 2, the straight pipe portion 40 is predetermined in the row direction along the flow direction of the exhaust gas generated by burning the waste in the incinerator and in the column direction orthogonal to the row direction. They are arranged in a matrix of M rows and N columns (M is an integer of 3 or more, N is an integer of 2 or more) at a pipe pitch.

<One side curved pipe part>
The one-side curved pipe portion 50 includes a straight pipe portion 40 in the mth row and nth column (m = 1, ..., M, n = 1, ..., N) and a (m + 1) th row (n + 1) th. ) One end of the row with the straight pipe portion 40 is connected to each other.

<Other side curved pipe part>
The other side curved pipe portion 60 connects the other ends of the straight pipe portion 40 in the (m + 1) th row and the nth column and the straight pipe portion 40 in the (m + 2) th row and nth column.

<Manufacturing of heat transfer tubes>
FIG. 3 is an external perspective view of a heat transfer tube constituting the heat exchanger according to the embodiment of the present invention. The heat transfer tube 10 is formed by bending a long tube by 180 ° in a state of being inclined at a predetermined obtuse angle θ in the depression angle direction with respect to the horizontal plane W, and forming the bent portion into a U shape. The other side curved tube portion 60 is used. In this way, the other side curved pipe portion 60 is formed in a shape that is curved with a predetermined bending radius.

Next, a long pipe is fed a certain distance, and this feed portion is designated as a straight pipe portion 40. In this way, the straight pipe portion 40 is formed in a shape extending linearly in a direction intersecting (orthogonal direction) with the flow direction of the exhaust gas.

After that, the pipe itself is bent again by 180 ° in a state of being inclined at a predetermined obtuse angle θ in the depression angle direction with respect to the horizontal plane W, and the bent portion is formed into a U shape and this is designated as a one-sided curved pipe portion 50. .. In this way, the one-side curved tube portion 50 is formed in a shape that is curved with a predetermined bending radius.

By repeating the above operation a plurality of times, as shown in FIG. 3, a straight pipe portion 40 having a shape extending linearly, a one-side curved pipe portion 50 having a shape curved with a predetermined bending radius, and another side bending. It can be formed into a shape in which the pipe portion 60 is seamless and continuous in a meandering shape. Since the bending process here does not involve the twisting process, the stress fatigue in the bending processing portion (one side curved pipe portion 50 and the other side curved pipe portion 60) is reduced, and the headers 123 and 133. In terms of strength, as compared with those shown in FIGS. 4 (e) and 4 (e') and FIGS. 4 (f) and 4 (f'), which are formed by joining the straight pipe portion 122 and the straight pipe portion 122 by welding to form a heat transfer tube. It is advantageous and the manufacturing cost can be kept low.

In the heat exchanger 1 configured as described above, as shown in FIGS. 1 (a) and 1 (b) and FIG. 2, the row direction along the flow direction of the exhaust gas and the row direction orthogonal to the row direction. A plurality of straight pipe portions 40 are arranged in a matrix of M rows and N columns (M is an integer of 3 or more and N is an integer of 2 or more) at a predetermined pipe pitch in each column direction. According to such an arrangement, when a plurality of straight pipe portions 40 are viewed in the exhaust gas flow direction, the straight pipe portions 40 in the next row are located between the straight pipe portions 40 adjacent to each other in the column direction in one row. Therefore, even if the exhaust gas contains dust, which is an adhesive substance, the flow path in the exhaust gas flow direction is not blocked by the dust.

Further, in the heat exchanger 1, one ends of the straight pipe portion 40 in the mth row and nth column and the straight pipe portion 40 in the (m + 1) th row and (n + 1) column are connected by a one-side curved pipe portion 50. Will be done. Since the one-side curved pipe portion 50 does not connect one ends of the straight pipe portions 40 adjacent to each other in the row direction in the same column, the pipe pitch of the straight pipe portions 40 adjacent to each other in the row direction in the same column is assumed to be the same. Even if the size is reduced until the adjacent straight pipe portions 40 come into contact with each other, one ends of the straight pipe portion 40 in the mth row and nth column and the straight pipe portion 40 in the (m + 1) th row and (n + 1) column are connected to each other. be able to.

Similarly, in the heat exchanger 1, the other ends of the straight pipe portion 40 in the (m + 1) row and the (n + 1) column and the straight pipe portion 40 in the (m + 2) row and the nth column are curved pipes on the other side. It is connected by the unit 60. Since the other side curved pipe portion 60 does not connect the other ends of the straight pipe portions 40 adjacent to each other in the row direction in the same column, the pipe pitch of the straight pipe portions 40 adjacent to each other in the row direction in the same column is tentatively set. Even if the size is reduced until the adjacent straight pipe portions 40 come into contact with each other, the other end of the straight pipe portion 40 in the (m + 1) th row and (n + 1) column and the straight pipe portion 40 in the (m + 2) th row and nth column. Can be connected to each other.

Therefore, the pipe pitch in the exhaust gas flow direction (row direction) can theoretically be shortened until the straight pipe portions 40 adjacent to each other in the row direction come into contact with each other, whereby the heat exchanger 1 can be made compact. ..

In the heat exchanger 1 of the present embodiment, as shown in FIG. 2, when the pipe pitch in the row direction in the plurality of straight pipe portions 40 is P and the pipe outer diameter of the plurality of straight pipe portions is D, D. It is preferable to satisfy the relationship of ≦ P ≦ 2.5D. In this way, it is possible to make the heat exchanger 100 (see FIGS. 4A and 4A) more compact than the conventional heat exchanger 100 having a grid pattern of about P = 3D. Further, by reducing the pipe pitch in the row direction until P = D, that is, the straight pipe portions 40 adjacent to each other in the row direction come into contact with each other in the same column, FIGS. 4 (b) and (b'), and FIG. 4 (c). And, it can be made much more compact than the staggered heat exchanger shown in (c').

The heat exchanger of the present invention has been described above based on one embodiment, but the present invention is not limited to the configuration described in the above embodiment, and the configuration is appropriately modified without departing from the spirit of the present invention. Is something that can be done.

(Separate embodiment)
In the above embodiment, the straight pipe portion 40 having a shape extending linearly is illustrated as the main pipe portion of the present invention, but it does not necessarily have to be linear, and even if it is an arc shape having a relatively large radius of curvature, it is spiral. It may be in the form. Further, in the above embodiment, as the one-side tube portion and the other-side tube portion of the present invention, the one-side curved tube portion 50 having a shape curved with a predetermined bending radius and the other-side curved tube portion 60 are exemplified. However, it does not necessarily have to be curved, and may be bent in a U shape.

The heat exchanger of the present invention can be used, for example, by incorporating it into a boiler of a waste incineration facility and using it for heat exchange with exhaust gas.

1 Heat exchanger 10 Heat transfer tube 20 One side support member 30 Other side support member 40 Straight pipe part (main pipe part)
50 One-sided curved pipe (one-sided pipe)
60 Other side curved pipe part (other side pipe part)

Claims (3)

A plurality of heat transfer tubes are provided, and of two fluids having different temperatures, one fluid flows inside the heat transfer tube, the other fluid flows outside the heat transfer tube, and the two fluids pass through the heat transfer tube. A heat exchanger configured to exchange heat between fluids.
The heat transfer tube is
A matrix of M rows and N columns (M is an integer of 3 or more, N is an integer of 2 or more) at a predetermined pipe pitch in the row direction along the flow direction of the other fluid and in the column direction orthogonal to the row direction. With multiple main units located in
The main section of the mth row and nth column (m = 1, ..., M, n = 1, ..., N) and the main section of the (m + 1) th row and th column (n + 1) in the plurality of main sections. One side tube that connects one end of the
The other side pipe portion that connects the other ends of the main pipe portion of the (m + 1) row and th (n + 1) column and the main pipe portion of the (m + 2) row and nth column in the plurality of main pipe portions, and the other side pipe portion.
Heat exchanger including. The main pipe portion has a shape extending linearly in a direction intersecting the flow direction of the other fluid, and both the one side pipe portion and the other side pipe portion have a shape curved with a predetermined bending radius. The heat exchanger according to claim 1. When the pipe pitch in the row direction in the plurality of main pipe portions is P and the pipe outer diameter of the plurality of main pipe portions is D, claim 1 or 2 satisfying the relationship of D ≦ P ≦ 2.5D. The heat exchanger described.

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