JP2020186884A - Gas appliance heat exchanger - Google Patents

Abstract

To provide a gas appliance heat exchanger capable of efficiently transmitting heat of exhaust gases to water in heat transfer pipes in a configuration where end parts of respective heat transfer pipes are suitably fitted.SOLUTION: A secondary heat exchanger 10 arranges respective first linear pipe parts 54 in a first parallel arrangement part 70 and respective second linear pipe parts 64 in a second parallel arrangement part 72 alternately with back and forth positions displaced in an area on a center side in a back and forth direction of a heat transfer pipe part 12. In an area on an end part side in the back and forth direction in the heat transfer pipe part 12, respective end parts in a plurality of first heat transfer pipes 50 and respective end parts in a plurality of the second heat transfer pipes 60 are arranged alternately vertically with positions back and forth displaced. A deviation amount in a back and forth direction between the first linear pipe parts 54 and the second linear pipe parts 64 in the area on the center side is larger than a deviation amount in the back and forth direction between the end parts of the first heat transfer pipes 50 and the end parts in the second heat transfer pipes 60 in an area on an end parts side.SELECTED DRAWING: Figure 8

Description

The present invention relates to a heat exchanger for gas appliances.

Conventionally, heat exchangers for gas appliances used for gas appliances such as hot water supply devices are known. For example, the heat exchanger for gas appliances disclosed in Patent Document 1 includes a casing whose inside is an exhaust gas (combustion exhaust) passage, and a plurality of heat transfer tubes (heat absorption tubes) housed in the casing. The structure is such that the water in the heat transfer tube (heat absorption tube) is heated by the heat of the exhaust gas (combustion exhaust) introduced into the casing.

Each of the plurality of heat transfer tubes has a linear tube portion (straight line portion) and a folded portion (arc-shaped folded portion), and has a meandering shape. The linear tube portion indicates the direction in which the exhaust gas flows. It is arranged in the casing in a form extending along the orthogonal direction. Further, each of the plurality of heat transfer tubes is arranged side by side in the vertical direction, and the positions are shifted in the direction in which the exhaust gas flows so that the linear tube portions of the upper and lower heat transfer tubes do not overlap each other. Arranged in a configuration. As a result, an exhaust gas passage is formed between the linear pipe portions of the plurality of heat transfer tubes.

Japanese Unexamined Patent Publication No. 2013-77943

However, in the conventional heat exchanger as disclosed in Patent Document 1, the exhaust gas tends to come into good contact with each heat transfer tube on the upstream side of the heat transfer tube portion, but the exhaust gas is exhausted on the central side or the downstream side of the heat transfer tube portion. It becomes difficult for the gas to make good contact with each heat transfer tube. As a result, it becomes difficult to efficiently transfer the heat of the exhaust gas on the central side or the downstream side.

In order to efficiently transfer heat in the heat transfer tube section, it is desirable to arrange the tubes so close to each other to some extent. In particular, in the region on the center side (the region on the center side in the front-rear direction in the heat transfer tube portion), it is difficult for the exhaust gas to directly hit the heat transfer tube, so each tube provided in multiple stages is arranged close to the front and back to improve thermal efficiency. It can be said that it is desirable to enhance the effect. However, in the area on the end side (the area on the end side in the front-rear direction in the heat transfer tube part), if the ends of the tubes provided in multiple stages are brought too close to the front and back, it is necessary to perform the processing to attach each end. There is a concern that sufficient space (for example, space required for forming through holes, space required for joining, etc.) cannot be secured sufficiently.

The present invention has been made to solve at least one of the above-mentioned problems, and each heat exchanger for a gas appliance capable of efficiently transferring the heat of the exhaust gas to the water in the heat transfer tube is transferred. The purpose is to realize a configuration that facilitates the processing required to attach the end of the heat tube.

The heat exchanger for gas appliances of the first disclosure is
A case with a peripheral wall that surrounds the exhaust gas passage space,
A heat transfer tube portion including a plurality of heat transfer tubes housed in the case,
It is a heat exchanger for gas appliances that has
The peripheral wall portion is provided with an exhaust gas discharge port on one side in the front-rear direction, an exhaust gas inflow port on the other side in the front-rear direction, and a side wall portion for attaching the heat transfer tube on one side in the left-right direction. ,
The side wall portion is provided with a first through hole group having a plurality of first through holes and a second through hole group having a plurality of second through holes, and the first through hole group and the second through hole group are provided. The holes are arranged apart from each other in the front-back direction.
Each of the plurality of heat transfer tubes is attached so that one end side corresponds to each of the first through holes of the first through hole group, and the other end side of each is attached to the second through hole of each of the second through hole groups. It is attached corresponding to the hole, and is fixed in multiple stages to the side wall portion in a configuration in which the positions in the vertical direction are shifted from each other.
The plurality of heat transfer tubes include a first heat transfer tube group including a plurality of first heat transfer tubes and a second heat transfer tube group including a plurality of second heat transfer tubes, and each of the first heat transfer tubes in the first heat transfer tube group. The first heat transfer tube and the second heat transfer tube in the second heat transfer tube group are alternately arranged in the vertical direction.
Each of the first heat transfer tubes includes a plurality of first linear tube portions that extend linearly from one side in the left-right direction to the other side.
The plurality of first linear pipe portions are arranged side by side from one side in the front-rear direction to the other side, and the front-rear distance between the pipe portions is equal at the first interval in the first region.
The first heat transfer tube group has a plurality of first parallel arrangement portions in which the first linear tube portions of each of the first regions are arranged one above the other.
Each of the second heat transfer tubes includes a plurality of second linear tube portions that extend linearly from one side in the left-right direction to the other side.
The plurality of the second linear tube portions are arranged side by side from one side in the front-rear direction to the other side, and the front-rear distance between the two pipe portions is equal to the first interval in the second region.
The second heat transfer tube group has a plurality of second parallel arrangement portions in which the second linear tube portions of each of the second regions are arranged one above the other.
Each of the first linear pipe portions in the first parallel arrangement portion and each of the second linear pipe portions in the second parallel arrangement portion are staggered up and down by shifting the front and rear positions by the first deviation amount. Lined up in
Each end of the plurality of first heat transfer tubes connected to the first through hole or the second through hole on one side in the front-rear direction from the second region, and the front and rear of the plurality of second heat transfer tubes. On one side of the direction, the first through hole or each end connected to the second through hole is staggered up and down by shifting the front and rear positions by the second deviation amount.
The front-rear distance between the pipe portions on one side of the plurality of second linear pipe portions in the front-rear direction is set to a second interval different from the first interval, so that the second deviation amount is larger than the first deviation amount. Is bigger.

The second disclosed heat exchanger for gas appliances is
A case with a peripheral wall that surrounds the exhaust gas passage space,
A heat transfer tube portion including a plurality of heat transfer tubes housed in the case,
It is a heat exchanger for gas appliances that has
The peripheral wall portion is provided with an exhaust gas discharge port on one side in the front-rear direction, an exhaust gas inflow port on the other side in the front-rear direction, and a side wall portion for attaching the heat transfer tube on one side in the left-right direction. ,
The side wall portion is provided with a first through hole group having a plurality of first through holes and a second through hole group having a plurality of second through holes, and the first through hole group and the second through hole group are provided. The holes are arranged apart from each other in the front-back direction.
Each of the plurality of heat transfer tubes is attached so that one end side corresponds to each of the first through holes of the first through hole group, and the other end side of each is attached to the second through hole of each of the second through hole groups. It is attached corresponding to the hole, and is fixed in multiple stages to the side wall portion in a configuration in which the positions in the vertical direction are shifted from each other.
The plurality of heat transfer tubes include a first heat transfer tube group including a plurality of first heat transfer tubes and a second heat transfer tube group including a plurality of second heat transfer tubes, and each of the first heat transfer tubes in the first heat transfer tube group. The first heat transfer tube and the second heat transfer tube in the second heat transfer tube group are alternately arranged in the vertical direction.
Each of the first heat transfer tubes includes a plurality of first linear tube portions that extend linearly from one side in the left-right direction to the other side.
The plurality of first linear pipe portions are arranged side by side from one side in the front-rear direction to the other side, and the front-rear distance between the pipe portions is equal at the first interval in the first region.
The first heat transfer tube group has a plurality of first parallel arrangement portions in which the first linear tube portions of each of the first regions are arranged one above the other.
Each of the second heat transfer tubes includes a plurality of second linear tube portions that extend linearly from one side in the left-right direction to the other side.
The plurality of the second linear tube portions are arranged side by side from one side in the front-rear direction to the other side, and the front-rear distance between the two pipe portions is equal to the first interval in the second region.
The second heat transfer tube group has a plurality of second parallel arrangement portions in which the second linear tube portions of each of the second regions are arranged one above the other.
Each of the first linear pipe portions in the first parallel arrangement portion and each of the second linear pipe portions in the second parallel arrangement portion are staggered up and down by shifting the front and rear positions by the first deviation amount. Lined up in
Each end of the plurality of first heat transfer tubes connected to the first through hole or the second through hole on one side in the front-rear direction, and the first of the plurality of second heat transfer tubes on one side in the front-rear direction. The through hole or each end connected to the second through hole is staggered up and down by shifting the front and rear positions by the second deviation amount.
In the second linear tube portion provided at one end of the plurality of second linear tube portions in the front-rear direction, the side connected to the first through hole or the second through hole is one side in the front-rear direction. The second deviation amount is larger than the first deviation amount due to the formation of the bent interval expanding portion.

In the above heat exchanger for gas appliances, the first linear pipe portion in the first parallel arrangement portion and the second linear pipe portion in the second parallel arrangement portion are positioned in the front-rear direction with the first deviation amount. The structure is such that they are staggered up and down. Therefore, it is possible to improve the thermal efficiency while effectively using the space.
Further, each end of the plurality of first heat transfer tubes connected to the first through hole or the second through hole on one side in the front-rear direction, and the first through hole or the above on one side in the front-rear direction of the plurality of second heat transfer tubes. The ends connected to the second through hole are arranged in a staggered manner vertically with the front and rear positions shifted by the second deviation amount. That is, since the pitch in the front-rear direction (second deviation amount) of the portion connected to the through hole can be secured larger than the pitch on the center side (first deviation amount), the pitch before and after the through hole becomes narrower. It is possible to suppress too much and eliminate or alleviate the difficulty of processing.

FIG. 1 is a front view schematically illustrating the internal structure of a hot water supply device including the heat exchanger for gas appliances according to the first embodiment. FIG. 2 is an explanatory diagram that conceptually illustrates the configuration of the hot water supply device of FIG. FIG. 3 is a perspective view schematically illustrating the heat exchanger for gas appliances of the first embodiment. FIG. 4 is a perspective view schematically illustrating a state in which the lid portion of the heat exchanger for gas appliances of Example 1 is removed. FIG. 5 is a side view schematically illustrating a case of the heat exchanger for gas appliances according to the first embodiment in a state where the header is removed. FIG. 6 is a plan view schematically illustrating a first heat transfer tube in the heat exchanger for gas appliances according to the first embodiment. FIG. 7 is a plan view schematically illustrating a second heat transfer tube in the heat exchanger for gas appliances according to the first embodiment. FIG. 8 is a plan view illustrating the positional relationship between the first heat transfer tube, the second heat transfer tube, and the side wall portion in the heat exchanger for gas appliances of the first embodiment. FIG. 9 shows a cross section of the heat exchanger for gas appliances of Example 1 in which a portion passing through the first linear tube portion is cut in a plane along the vertical direction and the front-rear direction, and the cut surface is viewed from the other side in the left-right direction. It is a figure. FIG. 10 is an enlarged view of FIG. 9 which is partially enlarged. FIG. 11A is an explanatory diagram that conceptually illustrates the flow of exhaust gas when the overlap width is less than 0. FIG. 11B is an explanatory diagram that conceptually illustrates the flow of exhaust gas when the overlapping width is 0 or more and is equal to or less than the radius of the first linear pipe portion. FIG. 11C is an explanatory diagram that conceptually illustrates the flow of exhaust gas when the overlapping width is larger than the radius of the first linear pipe portion. FIG. 12 is a perspective view schematically illustrating a state in which the lid portion of the heat exchanger for gas appliances of the second embodiment is removed. FIG. 13 is a plan view schematically illustrating a first heat transfer tube in the heat exchanger for gas appliances according to the second embodiment. FIG. 14 is a plan view schematically illustrating a second heat transfer tube in the heat exchanger for gas appliances according to the second embodiment. FIG. 15 is a plan view illustrating the positional relationship between the first heat transfer tube, the second heat transfer tube, and the side wall portion in the heat exchanger for gas appliances of the second embodiment. FIG. 16 shows a cross section of the heat exchanger for gas appliances according to the second embodiment, in which a portion passing through the first linear tube portion is cut in a plane along the vertical direction and the front-rear direction, and the cut surface is viewed from the other side in the left-right direction. It is a figure. FIG. 17 is an enlarged view of FIG. 16 which is partially enlarged.

Here, a desirable example of the present invention is shown.
The heat exchanger for gas appliances of the first disclosure is the end portion of the plurality of first heat transfer tubes connected to the first through hole or the second through hole on the side opposite to one side in the front-rear direction from the first region. And, of the plurality of second heat transfer tubes, the ends connected to the first through hole or the second through hole on the opposite side are staggered vertically with the front and rear positions shifted by the third deviation amount. There may be. Then, on the opposite side of the plurality of first linear pipe portions, the front-rear distance between the pipe portions is set to a third interval different from the first interval, so that the third deviation amount is larger than the first deviation amount. You may.
According to this configuration, the pitch in the front-rear direction of each end connected to the through hole is secured larger than the pitch on the center side (first deviation amount) on both the front-rear direction side and the opposite side of the heat transfer tube portion. be able to. Therefore, it is possible to prevent the pitch before and after the through hole from becoming too narrow on both sides in the front-rear direction, and to eliminate or alleviate the difficulty of processing.

The heat exchanger for gas appliances of the second disclosure includes each end connected to the first through hole or the second through hole on the side opposite to one side in the front-rear direction of the plurality of first heat transfer tubes, and a plurality of second heat exchangers. The two ends of the heat transfer tube, which are connected to the first through hole or the second through hole on the opposite side, may be arranged alternately in the vertical direction by shifting the front and rear positions by the third deviation amount. Then, in the first linear tube portion provided at the opposite end of the plurality of first linear tube portions, the side connected to the first through hole or the second through hole is bent to the opposite side. The third deviation amount may be larger than the first deviation amount due to the formation of the interval expanding portion.
According to this configuration, the pitch in the front-rear direction of each end connected to the through hole is secured larger than the pitch on the center side (first deviation amount) on both the front-rear direction side and the opposite side of the heat transfer tube portion. be able to. Therefore, it is possible to prevent the pitch before and after the through hole from becoming too narrow on both sides in the front-rear direction, and to eliminate or alleviate the difficulty of processing.

The plurality of heat transfer tubes may each have a common shape. According to this configuration, an increase in manufacturing cost can be suppressed as compared with the case where a plurality of heat transfer tubes having a plurality of shapes are used.

Each of the plurality of heat transfer tubes may be meandering and may have a non-rotational symmetric shape. In the first heat transfer tube group, each of the plurality of first heat transfer tubes may be arranged in every other step in the vertical direction. In the second heat transfer tube group, each of the plurality of second heat transfer tubes may be arranged in every other step in the vertical direction. Each of the plurality of second heat transfer tubes may be arranged in a posture in which the posture of the first heat transfer tube is turned inside out. According to this configuration, it can be used as the second heat transfer tube only by turning over the posture of the first heat transfer tube.

<Example 1>
Hereinafter, Example 1 will be described with reference to FIGS. 1 to 11.
(Configuration of hot water supply device 1)
The hot water supply device 1 shown in FIGS. 1 and 2 includes a first gas burner 2, a water inlet pipe 4, a hot water outlet pipe 6, a heat exchanger 8, a first connecting pipe 15, and the like, and heats tap water supplied from the outside. It has a function to make hot water flow. The first gas burner 2 (hot water supply burner) is a portion that burns combustion gas to generate combustion exhaust (exhaust gas). The water inlet pipe 4 is configured as a path through which water flows from the water inlet 16, and the hot water outlet pipe 6 is configured as a path for delivering hot water to the hot water outlet 18. The heat exchanger 8 includes a hot water supply side heat transfer pipe portion 11 interposed between the water inlet pipe 4 and the hot water outlet pipe 6, and the first gas burner 2 is used for water passing through the inside of the hot water supply side heat transfer pipe portion 11. It is the part that functions to transfer the heat generated by combustion.
The heat exchanger 8 includes a primary heat exchanger 9 and a secondary heat exchanger 10. The primary heat exchanger 9 is arranged on the upstream side of the combustion exhaust path of the first gas burner 2, and is a secondary heat exchanger. Reference numeral 10 is arranged on the downstream side of the combustion exhaust path. The hot water supply side heat transfer tube portion 11 includes a heat transfer tube portion 12 and a third heat transfer tube portion 13, the heat transfer tube portion 12 is provided in the secondary heat exchanger 10, and the third heat transfer tube portion 13 is the primary heat. It is provided in the exchanger 9. The heat transfer tube portion 12 of the secondary heat exchanger 10 is connected to the downstream side of the water inlet pipe 4, and the first connecting pipe 15 is connected to the downstream side of the heat transfer tube portion 12. The third heat transfer tube portion 13 of the primary heat exchanger 9 is connected to the downstream side of the first connecting pipe 15, and the hot water discharge pipe 6 is connected to the downstream side of the third heat transfer tube portion 13.
The heat exchanger 8 functions to recover the latent heat by the secondary heat exchanger 10 after recovering the sensible heat of the combustion exhaust by the primary heat exchanger 9. Specifically, the primary heat exchanger 9 transfers the combustion heat contained in the combustion exhaust generated by the first gas burner 2 to the water passing through the third heat transfer tube portion 13, and transmits the sensible heat energy. Heat is exchanged by transferring it to water. Further, the secondary heat exchanger 10 transfers the combustion heat after the combustion exhaust generated in the first gas burner 2 passes through the primary heat exchanger 9 to the water passing through the heat transfer tube portion 12, and the latent heat heat is transferred. Heat exchanges so that energy is transferred to water.

Further, the hot water supply device 1 is provided with a second gas burner 102, an outgoing pipe 104, a return pipe 106, a second connecting pipe 115, and the like, and has a function of performing additional cooking of the bath by using the heat exchanger 8 described above. Have. The second gas burner 102 (bath burner) is a portion that burns combustion gas to generate combustion exhaust (exhaust gas). The going pipe 104 is a path that guides water from the bathtub 20 side to the heat exchanger 8 via the inlet 116. The return pipe 106 is a path for guiding the water from the heat exchanger 8 to the bathtub 20 side via the outlet 118. The heat exchanger 8 described above includes a bath-side heat transfer tube portion 111 interposed between the forward pipe 104 and the return pipe 106, and the second gas burner 102 with respect to water passing through the inside of the bath-side heat transfer tube portion 111. It functions to transfer the heat generated by the combustion in the room.
The bath side heat transfer tube portion 111 includes a second heat transfer tube portion 112 and a fourth heat transfer tube portion 113, and the second heat transfer tube portion 112 is provided in the secondary heat exchanger 10 and includes a fourth heat transfer tube portion. The 113 is provided in the primary heat exchanger 9. The second heat transfer tube portion 112 of the secondary heat exchanger 10 is connected to the downstream side of the forward pipe 104, and the second connecting pipe 115 is connected to the downstream side of the second heat transfer tube portion 112. .. The fourth heat transfer tube portion 113 of the primary heat exchanger 9 is connected to the downstream side of the second connecting pipe 115, and the return pipe 106 is connected to the downstream side of the fourth heat transfer tube portion 113.
The primary heat exchanger 9 described above transfers the combustion heat contained in the combustion exhaust generated by the second gas burner 102 to the water passing through the fourth heat transfer tube portion 113, and transfers the sensible heat energy to the water passage. Heat exchange in the form of Further, the secondary heat exchanger 10 transfers the combustion heat after the combustion exhaust generated by the second gas burner 102 passes through the primary heat exchanger 9 to the water passing through the second heat transfer tube portion 112, and the latent heat is latent. Heat exchange so that the heat energy of the water is transferred to the water.

Further, the hot water supply device 1 includes a drain pipe 22 and a neutralizer 24. The upstream side of the drain pipe 22 is connected to the drain joint 26 (see FIG. 3) of the secondary heat exchanger 10, and the downstream side is connected to the neutralizer 24. The drain generated by the recovery of latent heat in the secondary heat exchanger 10 is discharged to the outside of the secondary heat exchanger 10 via the drain joint 26, and is sent to the neutralizer 24 through the drain pipe 22.

Further, the hot water supply device 1 includes a controller 28 as a control device. The controller 28 is configured as, for example, a known microcomputer or the like, and is configured to be able to acquire signals from various sensors provided in the hot water supply device 1, and various actuators provided in the hot water supply device 1 can be used. It has a controllable configuration. For example, the hot water supply device 1 operates the first gas burner 2 to generate hot water when the water flow sensor (not shown) detects the water flow in the water inlet pipe 4. As another example, the hot water supply device 1 operates the second gas burner 102 to re-cook the bath when the water flow sensor (not shown) detects the water flow in the going pipe 104.

(Configuration of secondary heat exchanger 10)
Next, the configuration of the secondary heat exchanger 10 will be described with reference to FIGS. 3 to 11. In this embodiment, the arrangement direction of the first heat transfer tubes 50 is the vertical direction of the secondary heat exchanger 10. Further, the left-right direction of the hot water supply device 1 is the left-right direction of the secondary heat exchanger 10, one side in the left-right direction is the right side of the secondary heat exchanger 10, and the other side in the left-right direction is the left side of the secondary heat exchanger 10. On the other side. Further, the direction orthogonal to the vertical direction and the horizontal direction of the secondary heat exchanger 10 is the front-rear direction of the secondary heat exchanger 10, one side in the front-rear direction is the front side of the secondary heat exchanger 10, and the other side in the front-rear direction. Is the rear side of the secondary heat exchanger 10.

The secondary heat exchanger 10 corresponds to an example of a heat exchanger for gas appliances, and has a case 30, a heat transfer tube portion 12, and a second heat transfer tube portion 112, as shown in FIGS. 3 and 4. The case 30 closes the peripheral wall portion 31 surrounding the exhaust gas passage space PS, the bottom wall portion 32 provided on the lower end side of the peripheral wall portion 31, and the opening 34 provided on the upper end portion of the peripheral wall portion 31. A lid 33, a pair of headers 38, 39, and a pair of second headers 138, 139 are provided.

The passage space PS is provided with a heat transfer tube portion 12 on one side in the left-right direction and a second heat transfer tube portion 112 on the other side in the left-right direction. The heat transfer tube portion 12 is in a state where the upstream side communicates with the pipe on the water inlet 16 side (specifically, the water inlet pipe 4) via the header 38, and the downstream side is the pipe on the hot water outlet 18 side via the header 39 (specifically). In general, it is in a state of communicating with the first connecting pipe 15). The upstream side of the second heat transfer tube portion 112 is in a state of communicating with the pipe on the inlet 116 side (specifically, the forward pipe 104) via the second header 138, and the downstream side is on the outlet 118 side via the second header 139. (Specifically, it is in a state of communicating with the second connecting pipe 115).

The peripheral wall portion 31 is provided with an exhaust gas discharge port 35 on one side in the front-rear direction, an exhaust gas inflow port 36 on the other side in the front-rear direction, and a side wall portion 37 to which a heat transfer tube 49 described later is attached to one side in the left-right direction. Is provided. The side wall portion 37 is configured to be separable and connectable to a portion of the peripheral wall portion 31 excluding the side wall portion 37.

As shown in FIG. 5, the side wall portion 37 includes a first through hole group 41 including a plurality of (seven in this embodiment) first through holes 40 and a plurality of (seven in this embodiment) second through holes. A second through-hole group 43 including the hole 42 is provided. The first through-hole group 41 and the second through-hole group 43 are arranged apart from each other in the front-rear direction. Each of the plurality of first through holes 40 is arranged so as to be displaced in the vertical direction, and is arranged so as to be alternately displaced in the front-rear direction. Each of the plurality of second through holes 42 is arranged so as to be displaced in the vertical direction and alternately arranged in the front-rear direction. The header 38 described above is attached corresponding to the first through hole group 41, and the header 39 is attached corresponding to the second through hole group 43.

The heat transfer tube unit 12 includes a plurality of (seven in this embodiment) heat transfer tubes 49 housed in the case 30. The plurality of heat transfer tubes 49 include a first heat transfer tube group 51 including a plurality of first heat transfer tubes 50 (see FIG. 6) and a second heat transfer tube group 61 including a plurality of second heat transfer tubes 60 (see FIG. 7). Equipped with. Each of the plurality of heat transfer tubes 49 has a common shape. Each of the plurality of heat transfer tubes 49 has a meandering shape and a non-rotational symmetric shape.

As shown in FIG. 6, the first heat transfer tube 50 includes a first end portion 52, a second end portion 53, a plurality of (six in this embodiment) first linear tube portions 54, and at least one. It has a first folded portion 55 (five in this embodiment) and at least one (one in this embodiment) spacing expanding portion 56. The first end portion 52 is provided on one end side of the first heat transfer tube 50, and the second end portion 53 is provided on the other end side of the first heat transfer tube 50. The plurality of first linear tube portions 54 have first linear tube portions 54A, 54B, 54C, 54D, 54E, 54F in order from the first end portion 52 side. At least one first folded-back portion 55 has first folded-back portions 55A, 55B, 55C, 55D, 55E in order from the first end portion 52 side.

As shown in FIG. 7, the second heat transfer tube 60 includes a third end portion 62, a fourth end portion 63, a plurality of (six in this embodiment) second linear tube portions 64, and at least one. It has a second folded portion 65 (five in this embodiment) and at least one (one in this embodiment) spacing expanding portion 66. The third end 62 is provided on one end side of the second heat transfer tube 60, and the fourth end 63 is provided on the other end side of the second heat transfer tube 60. The plurality of second linear tube portions 64 have second linear tube portions 64A, 64B, 64C, 64D, 64E, 64F in order from the third end 62 side. At least one second folded-back portion 65 has second folded-back portions 65A, 65B, 65C, 65D, 65E in order from the third end portion 62 side. The second heat transfer tube 60 has the same shape as the first heat transfer tube 50 in a state where the posture is turned upside down.

As shown in FIG. 8, each of the plurality of heat transfer tubes 49 is attached so that one end side corresponds to each first through hole 40 of the first through hole group 41, and the other end side of each is attached to the second through hole group 43. It is fixed to the side wall portion 37 in a configuration that is attached corresponding to each of the second through holes 42. Specifically, in each of the plurality of heat transfer tubes 49, the end portion on one end side (the first end portion 52 in the first heat transfer tube 50 and the third end portion 62 in the second heat transfer tube 60) first penetrates. While being inserted into the hole 40, it is fixed to the side wall portion 37 by brazing or the like, and at the other end of each (the second end 53 in the first heat transfer tube 50 and the second heat transfer tube 60 in the second heat transfer tube 60). The fourth end 63) is fixed to the side wall 37 by brazing or the like while being inserted through the second through hole 42.

As shown in FIGS. 8 and 9, the plurality of heat transfer tubes 49 are fixed to the side wall portion 37 in a plurality of stages in a configuration in which the positions of the heat transfer tubes 49 are shifted in the vertical direction. Specifically, on one end side of each of the heat transfer tubes 49 or the other end side of each (both sides in this embodiment), each end of the plurality of heat transfer tubes 49 is displaced in the vertical direction. It is fixed to the side wall portion 37 in a plurality of stages in a configuration in which each of them is staggered back and forth. The plurality of heat transfer tubes 49 are arranged so as to be closely spaced in the vertical direction.

As shown in FIG. 9, the first heat transfer tube 50 in the first heat transfer tube group 51 and the second heat transfer tube 60 in the second heat transfer tube group 61 are alternately arranged in the vertical direction. That is, in the first heat transfer tube group 51, each of the plurality of first heat transfer tubes 50 is arranged in every other step in the vertical direction, and in the second heat transfer tube group 61, each of the plurality of second heat transfer tubes 60 is arranged in the vertical direction. Arranged every other stage. The vertical gap between the first heat transfer tubes 50 is substantially the same as the outer diameter of the second heat transfer tube 60, and the vertical gap between the second heat transfer tubes 60 is approximately the same as the outer diameter of the first heat transfer tube 50. It is the same.

As shown in FIG. 8, the plurality of first heat transfer tubes 50 are attached so as to correspond to the first through hole 40 whose one end side is displaced to one side in the front-rear direction among the plurality of first through holes 40. The other end side is attached corresponding to the second through hole 42 which is displaced to one side in the front-rear direction among the plurality of second through holes 42. The plurality of second heat transfer tubes 60 are attached so that one end side thereof corresponds to the first through hole 40 which is displaced to the other side in the front-rear direction among the plurality of first through holes 40, and the other end side of each is a plurality of second through holes 40. It is attached corresponding to the second through hole 42 that is displaced to the other side in the front-rear direction of the through hole 42. Each of the plurality of second heat transfer tubes 60 is arranged in a posture in which the posture of the first heat transfer tube 50 is turned inside out.

As shown in FIG. 8, each of the plurality of first linear tube portions 54 extends linearly from one side in the left-right direction to the other side, and is arranged side by side from one side in the front-rear direction to the other side. Each of the plurality of second linear tube portions 64 extends linearly from one side in the left-right direction to the other side, and is arranged side by side from one side in the front-rear direction to the other side.

As shown in FIGS. 8 to 10, the first heat transfer tube group 51 has one or more first parallel arrangement portions 70 in which the first linear tube portions 54 of each first heat transfer tube 50 are arranged side by side. (6 in this embodiment). The first parallel arrangement portion 70 includes a first parallel arrangement portion 70A in which the first linear tube portions 54A of each first heat transfer tube 50 are arranged side by side, and a first straight line of each first heat transfer tube 50. A first parallel arrangement portion 70B in which the shape tube portions 54B are arranged vertically, and a first parallel arrangement portion 70C in which the first linear tube portions 54C of each first heat transfer tube 50 are arranged vertically. , The first parallel arrangement portion 70D in which the first linear tube portion 54D of each first heat transfer tube 50 is arranged vertically and the first linear tube portion 54E of each first heat transfer tube 50 are arranged vertically. It has a first parallel arrangement portion 70E arranged side by side, and a first parallel arrangement portion 70F in which the first linear tube portions 54F of each first heat transfer tube 50 are arranged vertically.

The second heat transfer tube group 61 has one or more second parallel arrangement portions 72 (6 in this embodiment) in which the second linear tube portions 64 of each second heat transfer tube 60 are arranged side by side. There is. The second parallel arrangement portion 72 includes a second parallel arrangement portion 72A in which the second linear tube portion 64A of each second heat transfer tube 60 is arranged vertically and a second straight line of each second heat transfer tube 60. A second parallel arrangement portion 72B in which the shape tube portions 64B are arranged vertically, and a second parallel arrangement portion 72C in which the second linear tube portions 64C of each second heat transfer tube 60 are arranged vertically. , The second parallel arrangement portion 72D in which the second linear tube portion 64D of each second heat transfer tube 60 is arranged vertically and the second linear tube portion 64E of each second heat transfer tube 60 are arranged vertically. It has a second parallel arrangement portion 72E arranged side by side, and a second parallel arrangement portion 72F in which the second linear tube portions 64F of each of the second heat transfer tubes 60 are arranged vertically.

The secondary heat exchanger 10 has a part of each first linear tube portion 54 in the first parallel arrangement portion 70 and each second linear shape in the second parallel arrangement portion 72 in a part region in the front-rear direction. A part of the pipe portion 64 overlaps vertically. In the following, in a part of the front-rear direction, a part of each first linear pipe portion 54 in the first parallel arrangement portion 70 and a part of each second linear pipe portion 64 in the second parallel arrangement portion 72. The area where and overlaps vertically is referred to as an overlapping area OA.

As shown in FIG. 8, the secondary heat exchanger 10 of the present embodiment has a part of each first linear tube portion 54A in the first parallel arrangement portion 70A and a second portion of each in the second parallel arrangement portion 72A. An overlapping region OA1 in which a part of the linear pipe portion 64A overlaps vertically, a part of each first linear pipe portion 54B in the first parallel arrangement portion 70B, and each second straight line in the second parallel arrangement portion 72B. An overlapping region OA2 in which a part of the shape tube portion 64B overlaps vertically, a part of each first linear tube portion 54C in the first parallel arrangement portion 70C, and each second linear shape in the second parallel arrangement portion 72C. An overlapping region OA3 in which a part of the pipe portion 64C overlaps vertically, a part of each first linear pipe portion 54D in the first parallel arrangement portion 70D, and each second linear pipe in the second parallel arrangement portion 72D. An overlapping region OA4 in which a part of the portion 64D overlaps vertically, a part of each first linear pipe portion 54E in the first parallel arrangement portion 70E, and each second linear pipe portion in the second parallel arrangement portion 72E. An overlapping region OA5 in which a part of 64E overlaps vertically, a part of each first linear pipe portion 54F in the first parallel arrangement portion 70F, and each second linear pipe portion 64F in the second parallel arrangement portion 72F. An overlapping region OA6, in which a part of the above overlaps with each other, is formed.

The interval expanding section 56 and the spacing expanding section 66 are each part of the first linear tube section 54 in the first parallel arrangement section 70 and each in the second parallel arrangement section 72 in a part of the front-rear direction. This is a portion adjusted so that a part of the second linear pipe portion 64 overlaps vertically. By the adjustment by the interval expanding portion 56 or the interval expanding portion 66, the secondary heat exchanger 10 becomes a part of each first linear tube portion 54 in the first parallel arrangement portion 70 in a part region in the front-rear direction. An overlapping region OA is formed in which a part of each of the second linear pipe portions 64 in the second parallel arrangement portion 72 is vertically overlapped with each other.

Specifically, the interval expanding portion 56 is closer to the first end portion 52 and the first end portion 52 side than the first folded portion 55 (first folded portion 55A in this embodiment) closest to the first end portion 52. It is interposed between the first linear tube portion 54 (in this embodiment, the first linear tube portion 54A). The interval expanding portion 56 has a form of moving toward the other side in the front-rear direction as the distance from the first end portion 52 increases. On the other hand, the second linear tube portion 64A extends linearly from the third end portion 62 to the other side in the left-right direction. As a result, the anteroposterior displacement width between the first linear tube portion 54A and the second linear tube portion 64A is smaller than the anteroposterior displacement width between the first end portion 52 and the third end portion 62. A part of the first linear pipe portion 54A and a part of the second straight pipe portion 64A are vertically overlapped with each other. That is, a part of each first linear pipe portion 54A in the first parallel arrangement portion 70A and a part of each second linear pipe portion 64A in the second parallel arrangement portion 72A are vertically overlapped. As a result, the overlapping region OA1 is formed.

Further, the interval expanding portion 66 is a second end portion 63 on the fourth end portion 63 side of the fourth end portion 63 and the second folded portion 65 (second folded portion 65E in this embodiment) closest to the fourth end portion 63. It is interposed between the linear pipe portion 64 (the second linear pipe portion 64F in this embodiment). The interval expanding portion 66 has a form of moving toward one side in the front-rear direction as the distance from the fourth end portion 63 increases. On the other hand, the first linear tube portion 54F extends linearly from the second end portion 53 to the other side in the left-right direction. As a result, the anteroposterior displacement width between the first linear tube portion 54F and the second linear tube portion 64F is smaller than the anteroposterior displacement width between the second end portion 53 and the fourth end portion 63. A part of the first straight pipe portion 54F and a part of the second straight pipe portion 64F are vertically overlapped with each other. That is, a part of each first linear pipe portion 54F in the first parallel arrangement portion 70F and a part of each second linear pipe portion 64F in the second parallel arrangement portion 72F are vertically overlapped. As a result, the overlapping region OA6 is formed.

Further, the secondary heat exchanger 10 includes a part of each first linear tube portion 54B in the first parallel arrangement portion 70B and a part of each second linear tube portion 64B in the second parallel arrangement portion 72B. The overlapping region OA2 in which is vertically overlapped, a part of each first linear tube portion 54C in the first parallel arrangement portion 70C, and a part of each second linear tube portion 64C in the second parallel arrangement portion 72C. The overlapping region OA3 that overlaps vertically, a part of each first linear pipe portion 54D in the first parallel arrangement portion 70D, and a part of each second linear pipe portion 64D in the second parallel arrangement portion 72D are vertically overlapped. The overlapping region OA4 overlapping the above, a part of each first linear tube portion 54E in the first parallel arrangement portion 70E, and a part of each second linear tube portion 64E in the second parallel arrangement portion 72E are vertically arranged. An overlapping overlapping region OA5 is formed.

As shown in FIG. 11A, when the first straight pipe portion 54 and the second straight pipe portion 64 do not overlap vertically (that is, when the overlap width OW is less than 0), the exhaust gas is exhaust gas. , It is easy to flow between the first straight pipe portion 54 and the second straight pipe portion 64. Therefore, the operation of the fan for flowing the exhaust gas can be suppressed. However, in this case, the exhaust gas easily comes into contact with the upstream surface of the first straight pipe portion 54 and the second straight pipe portion 64, but it is difficult to come into contact with the downstream surface. Here, the overlap width OW means that a part of each first linear pipe portion 54 in the first parallel arrangement portion 70 and a part of each second linear pipe portion 64 in the second parallel arrangement portion 72. In the overlapping region OA that overlaps vertically, it refers to the width that overlaps in the front-rear direction.

On the other hand, as shown in FIGS. 11B and 11C, a part of the first linear pipe portion 54 and a part of the second straight pipe portion 64 are vertically overlapped (on the other hand). That is, when the overlap width OW is 0 or more), the first linear tube portion 54 is compared with the case where the first linear tube portion 54 and the second linear tube portion 64 are not vertically overlapped. The distance between the and the second linear tube portion 64 is narrowed. Therefore, the flow of the exhaust gas after passing between the first straight pipe portion 54 and the second straight pipe portion 64 tends to be turbulent, and as a result, the first straight pipe portion 54 and the second straight line. It becomes easy to come into contact with the surface on the downstream side of the tubular portion 64.

However, as shown in FIG. 11C, if the overlapping width OW is too large, the gap between the first linear pipe portion 54 and the second linear pipe portion 64 becomes too small, and it is difficult for the exhaust gas to pass through. Become. In this case, it becomes necessary to increase the operation of the fan for flowing the exhaust gas. Therefore, as shown in FIG. 11B, the overlap width OW is 0 or more and the radius R1 of the first linear tube portion 54 (specifically, the outer diameter of the first linear tube portion 54). It is preferably one-half) or less, and one-half of the radius R1 of the first linear tube portion 54 (specifically, one-fourth of the outer diameter of the first linear tube portion 54). Is more preferable. By doing so, the heat of the exhaust gas can be efficiently transferred to the water in the first linear pipe portion 54 and the second linear pipe portion 64 while suppressing the operation of the fan for flowing the exhaust gas. The radius R1 (half of the outer diameter) of the first linear tube portion 54 and the radius R2 (half of the outer diameter) of the second linear tube portion 64 are the same.

Since the second heat transfer tube portion 112 is arranged in the same manner as the heat transfer tube portion 12, detailed description thereof will be omitted.

(effect)
The secondary heat exchanger 10 of the first embodiment includes a case 30 including a peripheral wall portion 31 surrounding an exhaust gas passage space, and a heat transfer tube portion 12 including a plurality of heat transfer tubes 49 housed in the case 30. The peripheral wall portion 31 is provided with an exhaust gas discharge port 35 on one side in the front-rear direction, an exhaust gas inflow port 36 on the other side in the front-rear direction, and a side wall portion 37 to which a heat transfer tube 49 is attached to one side in the left-right direction. Is provided. The side wall portion 37 is provided with a first through hole group 41 having a plurality of first through holes 40 and a second through hole group 43 having a plurality of second through holes 42, and the first through hole group is provided. 41 and the second through hole group 43 are arranged apart from each other in the front-rear direction. Each of the plurality of heat transfer tubes 49 is attached so that one end side corresponds to each first through hole 40 of the first through hole group 41, and the other end side of each is the second of each of the second through hole group 43. It is attached so as to correspond to the through hole 42, and is fixed to the side wall portion 37 in a plurality of stages in a configuration in which the positions in the vertical direction are shifted from each other. Further, the plurality of heat transfer tubes 49 include a first heat transfer tube group 51 including a plurality of first heat transfer tubes 50, and a second heat transfer tube group 61 including a plurality of second heat transfer tubes 60, and the first transfer is provided. The first heat transfer tubes 50 in the heat tube group 51 and the second heat transfer tubes 60 in the second heat transfer tube group 61 are alternately arranged in the vertical direction. With such a configuration as the basic configuration, each effect is achieved by the following features.

Each of the first heat transfer tubes 50 includes a plurality of first linear tube portions 54 extending linearly from one side in the left-right direction to the other side. The plurality of first linear pipe portions 54 are arranged side by side from one side (front side) to the other side (rear side) in the front-rear direction, and the front-rear distance between the pipe portions is equal at the first interval in the first region AR1. It has become. The first heat transfer tube group 51 has a plurality of first parallel arrangement portions 70 in which the first linear tube portions 54 of the first region AR1 are arranged one above the other. On the other hand, each of the second heat transfer tubes 60 includes a plurality of second linear tube portions 64 extending linearly from one side (front side) to the other side (rear side) in the left-right direction, and a plurality of second linear tube portions 64. Are arranged side by side from one side (front side) to the other side (rear side) in the front-rear direction, and the front-rear distance between the pipe portions in the second region AR2 is equal to the first distance. The second heat transfer tube group 61 has a plurality of second parallel arrangement portions 72 in which the second linear tube portions 64 of the second region AR2 are arranged one above the other. The second linear tube portion 64F provided at one end (rear side) in the front-rear direction of the plurality of second linear tube portions 64 is connected to the first through hole or the second through hole. The interval expanding portion 66 is formed by bending one side (rear side) in the front-rear direction. Then, each of the first linear tube portions 54 in the first parallel arrangement portion 70 and each second linear tube portion 64 in the second parallel arrangement portion 72 are displaced from each other by the first deviation amount T1. Line up and down alternately. Then, each end of the plurality of first heat transfer tubes 50 connected to the first through hole or the second through hole on one side (rear side) in the front-rear direction, and one side of the plurality of second heat transfer tubes 60 in the front-rear direction (rear side). On the rear side), the first through hole or each end connected to the second through hole is staggered up and down with the front and rear positions shifted by the second deviation amount T2. The second deviation amount T2 is larger than the first deviation amount T1.
According to this configuration, while adopting a configuration that can effectively utilize the space on the center side in the front-rear direction to improve the thermal efficiency, the pitch (second deviation amount T2) in the front-rear direction of the portion connected to the through hole is further increased. It can be secured larger than the pitch on the center side (first deviation amount T1). Therefore, it is possible to prevent the pitch before and after the through hole from becoming too narrow, and to eliminate or alleviate the difficulty of processing.

Specifically, the first linear tube portion 54A and the second linear tube portion 64A partially overlap each other vertically, and the first linear tube portion 54A and the second linear tube portion 54A do not overlap at all. The gap between the second linear tube portion 64A and the second linear tube portion 64A is small. Due to such a configuration, when the exhaust gas passes through the gap between the first straight pipe portion 54A and the second straight pipe portion 64A, the pressure of the exhaust gas is increased, and after passing, the pressure is reduced. It is easy for the flow to be disturbed. As a result, the exhaust gas easily comes into contact with not only the upstream surface but also the downstream surface of the outer peripheral surfaces of the first straight pipe portion 54A and the second straight pipe portion 64A, so that the heat of the exhaust gas is generated. Energy can be transferred more efficiently to the water in the heat transfer tube 49.

Further, the first linear tube portion 54A provided at the end of the plurality of first linear tube portions 54 on the opposite side (front side) to one side (rear side) in the front-rear direction is a first through hole or a second through hole. An interval expanding portion 56 (another spacing expanding portion) is formed by bending the side connected to the through hole to the opposite side (front side). Then, each end of the plurality of first heat transfer tubes 50 connected to the first through hole or the second through hole on the opposite side (front side), and the opposite side (front side) of the plurality of second heat transfer tubes 60. ), The ends connected to the first through hole or the second through hole are staggered up and down with the front and rear positions shifted by the third deviation amount T3. The third deviation amount T3 is larger than the first deviation amount T1.
According to this configuration, the pitch in the front-rear direction of each end connected to the through hole is secured larger than the pitch on the center side (first deviation amount) on both the front-rear direction side and the opposite side of the heat transfer tube portion 12. can do. Therefore, it is possible to prevent the pitch before and after the through hole from becoming too narrow on both sides in the front-rear direction, and to eliminate or alleviate the difficulty of processing.

Further, the secondary heat exchanger 10 has a part of each first linear tube portion 54 in the first parallel arrangement portion 70 and each second straight line in the second parallel arrangement portion 72 in a part region in the front-rear direction. A part of the shape tube portion 64 overlaps vertically. Due to such a configuration, the gap between the first linear tube portion 54 and the second linear tube portion 64 becomes smaller. Therefore, when the exhaust gas passes through the gap between the first straight pipe portion 54 and the second straight pipe portion 64, the exhaust gas flows in a narrower region at a higher flow velocity (a state in which the pressure is increased). Therefore, the heat energy of the exhaust gas can be more efficiently transferred to the water in the heat transfer tube.

Further, the secondary heat exchanger 10 includes a part of each first linear tube portion 54 in the first parallel arrangement portion 70 and a part of each second linear tube portion 64 in the second parallel arrangement portion 72. In the overlapping region OA where is vertically overlapped, the overlapping width OW in the front-rear direction is smaller than the radius R1 of the first linear pipe portion 54. According to this configuration, the overlap width OW in the front-rear direction becomes too small, so that the gap between the first straight pipe portion 54 and the second straight pipe portion 64 becomes too small, and the exhaust gas becomes the first. It is possible to prevent it from becoming difficult to pass through the gap between the linear pipe portion 54 and the second straight pipe portion 64.

Further, each of the plurality of heat transfer tubes 49 has a common shape. According to this configuration, an increase in manufacturing cost can be suppressed as compared with the case where a plurality of heat transfer tubes 49 having a plurality of shapes are used.

Further, each of the plurality of heat transfer tubes 49 has a meandering shape and a non-rotational symmetric shape. In the first heat transfer tube group 51, each of the plurality of first heat transfer tubes 50 is arranged in every other step in the vertical direction. In the second heat transfer tube group 61, each of the plurality of second heat transfer tubes 60 is arranged in every other step in the vertical direction. Each of the plurality of second heat transfer tubes 60 is arranged in a posture in which the posture of the first heat transfer tube 50 is turned inside out. According to this configuration, it can be used as the second heat transfer tube 60 only by turning over the posture of the first heat transfer tube 50.

<Example 2>
Next, the secondary heat exchanger 210 of the second embodiment will be described with reference to FIGS. 12 to 17 and the like. The secondary heat exchanger 210 of the second embodiment shown in FIG. 12 and the like differs from the secondary heat exchanger 10 of the first embodiment only in the shapes of the first heat transfer tube and the second heat transfer tube. This is the same as the secondary heat exchanger 10 of Example 1. Therefore, the same parts as those of the secondary heat exchanger 10 of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The heat transfer tube portion 212 includes a first heat transfer tube group 251 including a plurality of first heat transfer tubes 250 (see FIG. 13) and a second heat transfer tube group 261 including a plurality of second heat transfer tubes 260 (see FIG. 14). Equipped. The plurality of heat transfer tubes 249 constituting the heat transfer tube portion 212 each have a common shape. Each of the plurality of heat transfer tubes 249 has a meandering shape and a non-rotational symmetric shape.

As shown in FIG. 13, the first heat transfer tube 250 includes a first end portion 252, a second end portion 253, a plurality of (six in this embodiment) first linear tube portions 254, and at least one. It has a first folded portion 255 (five in this embodiment). The first end portion 252 is provided on one end side of the first heat transfer tube 250, and the second end portion 253 is provided on the other end side of the first heat transfer tube 250. The plurality of first linear tube portions 254 have first linear tube portions 254A, 254B, 254C, 254D, 254E, 254F in order from the first end portion 252 side. At least one first folded-back portion 255 has first folded-back portions 255A, 255B, 255C, 255D, 255E in order from the first end portion 252 side.

The gap between the first linear pipe portion 254A and the first straight pipe portion 254B is W1, and the gap between the other first straight pipe portions 254 is W2 (specifically, the first The gap W2 between the straight pipe portion 254B and the first straight pipe portion 254C, the gap W2 between the first straight pipe portion 254C and the first straight pipe portion 254D, the first linear shape. It is longer than the gap W2 between the pipe portion 254D and the first linear pipe portion 254E and the gap W2) between the first straight pipe portion 254E and the first linear pipe portion 254F.

As shown in FIG. 14, the second heat transfer tube 260 includes a third end portion 262, a fourth end portion 263, a plurality of (six in this embodiment) second linear tube portions 264, and at least one. It has a second folded portion 265 (five in this embodiment). The third end portion 262 is provided on one end side of the second heat transfer tube 260, and the fourth end portion 263 is provided on the other end side of the second heat transfer tube 260. The plurality of second linear tube portions 264 have second linear tube portions 264A, 264B, 264C, 264D, 264E, 264F in order from the third end portion 262 side. At least one second folded-back portion 265 has second folded-back portions 265A, 265B, 265C, 265D, 265E in order from the third end portion 262 side. The second heat transfer tube 260 has the same shape as the first heat transfer tube 250 in a state where the posture is turned upside down.

The gap between the second straight pipe portion 264E and the second straight pipe portion 264F is W4, and the gap between the other second straight pipe portions 264 is W3 (specifically, the second The gap W3 between the straight pipe portion 264A and the second straight pipe portion 264B, the gap W3 between the second straight pipe portion 264B and the second straight pipe portion 264C, the second linear shape. It is longer than the gap W3 between the pipe portion 264C and the second linear pipe portion 264D and the gap gap W3) between the second linear pipe portion 264D and the second linear pipe portion 264E.

As shown in FIG. 15, the first heat transfer tube 250 and the second heat transfer tube 260 are arranged in the same manner as the first heat transfer tube 50 and the second heat transfer tube 60 of the first embodiment.

The first heat transfer tube group 251 of the second embodiment has one or more first parallel arrangement portions 270 in which the first linear tube portions 254 of the first heat transfer tubes 250 are arranged side by side (6 in this embodiment). ) Have. The first parallel arrangement portion 270 includes a first parallel arrangement portion 270A in which the first linear tube portions 254A of each first heat transfer tube 250 are arranged side by side, and a first straight line of each first heat transfer tube 250. A first parallel arrangement portion 270B in which the shape tube portions 254B are arranged vertically, and a first parallel arrangement portion 270C in which the first linear tube portions 254C of each of the first heat transfer tubes 250 are arranged vertically. , The first parallel arrangement portion 270D in which the first linear tube portion 254D of each first heat transfer tube 250 is arranged vertically and the first linear tube portion 254E of each first heat transfer tube 250 are arranged vertically. It has a first parallel arrangement portion 270E arranged side by side, and a first parallel arrangement portion 270F in which the first linear tube portions 254F of each first heat transfer tube 250 are arranged side by side.

The second heat transfer tube group 261 of the second embodiment has one or more second parallel arrangement portions 272 in which the second linear tube portions 264 of each second heat transfer tube 260 are arranged side by side (6 in this embodiment). ) Have. The second parallel arrangement portion 272 includes a second parallel arrangement portion 272A in which the second linear tube portion 264A of each second heat transfer tube 260 is arranged vertically, and a second straight line of each second heat transfer tube 260. A second parallel arrangement portion 272B in which the shape tube portions 264B are arranged vertically, and a second parallel arrangement portion 272C in which the second linear tube portions 264C of each second heat transfer tube 260 are arranged vertically. , The second parallel arrangement portion 272D in which the second linear tube portion 264D of each second heat transfer tube 260 is arranged vertically and the second linear tube portion 264E of each second heat transfer tube 260 are arranged vertically. It has a second parallel arrangement portion 272E arranged side by side, and a second parallel arrangement portion 272F in which the second linear tube portions 264F of each second heat transfer tube 260 are arranged side by side.

The first folded-back portion 255A and the second folded-back portion 265E described above correspond to an example of the adjusting portion. The first folded-back portion 255A is interposed between the first end portion 252 and the first linear tube portions 254B, 254C, 254D, 254E in the first heat transfer tube 250. The second folded-back portion 256E is interposed between the fourth end portion 263 and the second linear tube portions 264B, 264C, 264D, 264E in the second heat transfer tube 260. The width dimension of the first folded portion 255A in the front-rear direction is formed to be larger than the width dimension of the first folded portion 255B, 255C, 255D, 255E which is the other first folded portion 255. The width dimension of the second folded portion 265E in the front-rear direction is formed to be larger than the width dimension of the second folded portion 265A, 265B, 265C, 265D, which is the other second folded portion 265, in the front-rear direction.

As a result, the first folded-back portion 255A and the second folded-back portion 265E are a part of each of the first linear pipe portions 254B in the first parallel arrangement portion 270B and the second parallel arrangement portion 272B in a part region in the front-rear direction. Adjusted so that a part of each of the second linear pipe portions 264B in the above is overlapped vertically, and a part of each first linear pipe portion 254C in the first parallel arrangement portion 270C and a part of the second parallel arrangement portion 272C in the first parallel arrangement portion 270C. Adjust so that a part of each second linear tube portion 264C overlaps vertically, and a part of each first linear tube portion 254D in the first parallel arrangement section 270D and a part of each in the second parallel arrangement section 272D. Adjusted so that a part of the second linear tube portion 264D of the above is overlapped vertically, and a part of each of the first linear tube portions 254E in the first parallel arrangement portion 270E and a part of each in the second parallel arrangement portion 272E. Adjust so that a part of the second linear tube portion 264E overlaps vertically.

That is, the secondary heat exchanger 10 is a part of each first linear tube portion 254B in the first parallel arrangement portion 270B and a part of each second linear tube portion 264B in the second parallel arrangement portion 272B. The overlapping region OA22, which overlaps vertically, and a part of each first linear pipe portion 254C in the first parallel arrangement portion 270C and a part of each second linear pipe portion 264C in the second parallel arrangement portion 272C. The overlapping region OA23, which is vertically overlapped with each other, and a part of each first linear pipe portion 254D in the first parallel arrangement portion 270D and a part of each second linear pipe portion 264D in the second parallel arrangement portion 272D. The overlapping region OA24 that overlaps vertically, a part of each first linear pipe portion 254E in the first parallel arrangement portion 270E, and a part of each second linear pipe portion 264E in the second parallel arrangement portion 272E are vertically overlapped. An overlapping region OA25 that overlaps with the above is formed.

Also in this configuration, the secondary heat exchanger 210 is a part of each first linear tube portion 254 in the first parallel arrangement portion 270 and each second in the second parallel arrangement portion 272 in a part region in the front-rear direction. 2 A part of the linear tube portion 64 is vertically overlapped. Specifically, a part of each first linear pipe portion 254 in the first parallel arrangement portion 70 and a part of each second linear pipe portion 264 in the second parallel arrangement portion 272 are overlapped vertically. In the region OA, the overlap width OW in the front-rear direction is smaller than the radius R1 of the first linear pipe portion 254.

Here, the effect of this configuration will be illustrated.
In the secondary heat exchanger 210, each of the first heat transfer tubes 250 includes a plurality of first linear tube portions 254 extending linearly from one side in the left-right direction to the other side. The plurality of first linear pipe portions 254 are arranged side by side from one side (front side) to the other side (rear side) in the front-rear direction, and the front-rear distance W2 between the pipe portions is equal to the first distance in the first region AR1. It is an interval. The first heat transfer tube group 251 has a plurality of first parallel arrangement portions 270 in which the first linear tube portions 254 of the first region AR1 are arranged one above the other. On the other hand, each of the second heat transfer tubes 260 includes a plurality of second linear tube portions 264 extending linearly from one side in the left-right direction to the other side. The plurality of second linear pipe portions 264 are arranged side by side from one side (front side) to the other side (rear side) in the front-rear direction, and the front-rear distance W3 between the pipe portions is equal to the first distance in the second region AR2. It is an interval. On one side (rear side) in the front-rear direction of the second region AR2, the front-rear distance W4 between the pipe portions is the second interval (the interval is different from the first interval and larger than the first interval). The second heat transfer tube group 261 has a plurality of second parallel arrangement portions 272 in which the second linear tube portions 264 of the second region AR2 are arranged one above the other. In such a configuration, each of the first linear tube portions 254 in the first parallel arrangement portion 270 and each second linear tube portion 264 in the second parallel arrangement portion 272 are front and rear with a first deviation amount T1. They are staggered up and down in different positions. Each end connected to the first through hole or the second through hole on one side (rear side) in the front-rear direction of the plurality of first heat transfer tubes 250, and one side (rear side) in the front-rear direction of the plurality of second heat transfer tubes 260. ), The ends connected to the first through hole or the second through hole are staggered vertically with the front and rear positions shifted by the second deviation amount T2. The second deviation amount T2 is larger than the first deviation amount T1.
According to this configuration, while adopting a configuration that can effectively utilize the space on the center side in the front-rear direction to improve the thermal efficiency, the pitch (second deviation amount T2) in the front-rear direction of the portion connected to the through hole is further increased. It can be secured larger than the pitch on the center side (first deviation amount T1). Therefore, it is possible to prevent the pitch before and after the through hole from becoming too narrow, and to eliminate or alleviate the difficulty of processing.

Further, in the plurality of first linear tube portions 254, the front-rear distance W1 between the pipe portions is the third interval (with the first interval) on the side (front side) opposite to one side (rear side) in the front-rear direction from the first region AR1. Are different intervals, which are larger than the first interval). Then, each end of the plurality of first heat transfer tubes 250 connected to the first through hole or the second through hole on the opposite side (front side), and the opposite side of the plurality of second heat transfer tubes 260 (the opposite side). On the front side), the ends connected to the first through hole or the second through hole are arranged alternately vertically with the front and rear positions shifted by the third deviation amount T3. The third deviation amount T3 is larger than the first deviation amount T1. The interval W2 and the interval W3 have the same value (first interval). The interval W4 (third interval) is the same interval as the interval W1 (second interval). Further, the third deviation amount T3 is the same deviation amount as the second deviation amount T2. According to this configuration, the pitch in the front-rear direction of each end connected to the through hole is set to the pitch on the center side (first) on both the front-rear direction side (rear side) and the opposite side (front side) of the heat transfer tube portion 212. It can be secured larger than the deviation amount T1). Therefore, it is possible to prevent the pitch before and after the through hole from becoming too narrow on both sides in the front-rear direction, and to eliminate or alleviate the difficulty of processing.

<Other Examples>
The present invention is not limited to the examples described in the above description and drawings, and for example, the following examples are also included in the technical scope of the present invention.

In each of the above-described embodiments, each end of the plurality of heat transfer tubes 49 is configured to be displaced in the vertical direction on both sides of each end side and each other end side of the plurality of heat transfer tubes 49. Was staggered back and forth and fixed to the side wall in multiple stages. However, in only one of the one end side or the other end side of each of the plurality of heat transfer tubes 49, each end portion of the plurality of heat transfer tubes 49 is configured to be displaced in the vertical direction and each of them is moved back and forth. It may be configured to be fixed in a plurality of stages to the side wall portion in a configuration in which the components are staggered.

In the first embodiment described above, by interposing the interval expanding portion 56 between the first end portion 52 and the first linear pipe portion 54A, a part of the first linear pipe portion 54A and the second linear pipe portion 54A are formed. The configuration was adjusted so that a part of the pipe portion 64A overlaps vertically, but by interposing the interval expanding portion 66 between the third end portion 62 and the second linear pipe portion 64A, the first A part of the linear pipe portion 54A and a part of the second straight pipe portion 64A may be adjusted so as to overlap each other vertically.

In the first embodiment described above, by interposing the interval expanding portion 66 between the fourth end portion 63 and the second linear pipe portion 64F, a part of the first linear pipe portion 54F and the second linear pipe portion are formed. The configuration was adjusted so that a part of the pipe portion 64F overlaps vertically, but by interposing the interval expanding portion 56 between the second end portion 53 and the first linear pipe portion 54F, the first A part of the linear pipe portion 54A and a part of the second straight pipe portion 64A may be adjusted so as to overlap each other vertically.

In the second embodiment described above, both the first folded-back portion 255A and the second folded-back portion 255A are used so that a part of the first linear tube portion 254 and a part of the second linear tube portion 264 are vertically overlapped with each other. However, it may be adjusted by either one of the first folded-back portion 255A and the second folded-back portion 255A.

In the above-described second embodiment, the width dimension of the first folded-back portion 255A in the front-rear direction is set to the width dimension of the other first folded-back portion 255 (in the second embodiment, the first folded-back portion 255B, 255C, 255D, 255E). However, the configuration may be smaller than the width dimension in the front-rear direction of the other first folded-back portion 255 (in the second embodiment, the first folded-back portion 255B, 255C, 255D, 255E). Further, in the above-described second embodiment, the width dimension of the second folded-back portion 265E in the front-rear direction is set to the front-rear direction of the other second folded-back portion 265 (in the second embodiment, the second folded-back portions 265A, 265B, 265C, 265D). Although it is configured to be larger than the width dimension, it may be configured to be smaller than the width dimension in the front-rear direction of the other second folded-back portion 265 (in the second embodiment, the second folded-back portion 265A, 265B, 265C, 265D).

In Example 2 described above, the width dimension of the second folded portion 265E in the front-rear direction is made larger than the width dimension of the other second folded portion 265 (second folded portion 265A, 265B, 265C, 265D) in the front-rear direction. As a result, a part of the second straight pipe portion 264 and a part of the second straight pipe portion 264 are adjusted so as to overlap each other vertically, but the width dimension of the first folded portion 255A in the front-rear direction is adjusted. , A part of the first linear tube portion 254 and the second linear tube by making it smaller than the width dimension in the front-rear direction of the other first folded portion 255 (first folded portion 255B, 255C, 255D, 255E). The configuration may be adjusted so that a part of the portion 264 overlaps vertically.

In each of the above-described embodiments, the configuration is such that the second heat transfer tube portion 112 is provided, but the second heat transfer tube portion 112 may not be provided.

In each of the above-described embodiments, the secondary heat exchanger 10 is used as a heat exchanger for gas appliances, but the heat exchanger 8 may be used as a heat exchanger for gas appliances, and the primary heat exchanger 9 may be used as heat for gas appliances. It may be used as an exchanger.

10,210 ... Secondary heat exchanger (heat exchanger for gas appliances)
12, 212 ... Heat transfer tube part 30 ... Case 31 ... Peripheral wall part 35 ... Discharge port 36 ... Inflow port 40 ... First through hole 41 ... First through hole group 42 ... Second through hole 43 ... Second through hole group 49, 249 ... Heat transfer tube 50, 250 ... 1st heat transfer tube 51,251 ... 1st heat transfer tube group 54,254 ... 1st linear tube part 56 ... Spacing expansion part (other spacing expansion part)
60, 260 ... 2nd heat transfer tube 61,261 ... 2nd heat transfer tube group 64,264 ... 2nd linear tube part 66 ... Spacing expansion part 70, 270 ... 1st parallel arrangement part 72, 272 ... 2nd parallel arrangement part PS ... Passing space OA ... Overlapping area OW ... Overlapping width

Claims (6)

A case with a peripheral wall that surrounds the exhaust gas passage space,
A heat transfer tube portion including a plurality of heat transfer tubes housed in the case,
It is a heat exchanger for gas appliances that has
The peripheral wall portion is provided with an exhaust gas discharge port on one side in the front-rear direction, an exhaust gas inflow port on the other side in the front-rear direction, and a side wall portion for attaching the heat transfer tube on one side in the left-right direction. ,
The side wall portion is provided with a first through hole group having a plurality of first through holes and a second through hole group having a plurality of second through holes, and the first through hole group and the second through hole group are provided. The holes are arranged apart from each other in the front-back direction.
Each of the plurality of heat transfer tubes is attached so that one end side corresponds to each of the first through holes of the first through hole group, and the other end side of each is attached to the second through hole of each of the second through hole groups. It is attached corresponding to the hole, and is fixed in multiple stages to the side wall portion in a configuration in which the positions in the vertical direction are shifted from each other.
The plurality of heat transfer tubes include a first heat transfer tube group including a plurality of first heat transfer tubes and a second heat transfer tube group including a plurality of second heat transfer tubes, and each of the first heat transfer tubes in the first heat transfer tube group. The first heat transfer tube and the second heat transfer tube in the second heat transfer tube group are alternately arranged in the vertical direction.
Each of the first heat transfer tubes includes a plurality of first linear tube portions that extend linearly from one side in the left-right direction to the other side.
The plurality of first linear pipe portions are arranged side by side from one side in the front-rear direction to the other side, and the front-rear distance between the pipe portions is equal at the first interval in the first region.
The first heat transfer tube group has a plurality of first parallel arrangement portions in which the first linear tube portions of each of the first regions are arranged one above the other.
Each of the second heat transfer tubes includes a plurality of second linear tube portions that extend linearly from one side in the left-right direction to the other side.
The plurality of the second linear tube portions are arranged side by side from one side in the front-rear direction to the other side, and the front-rear distance between the two pipe portions is equal to the first interval in the second region.
The second heat transfer tube group has a plurality of second parallel arrangement portions in which the second linear tube portions of each of the second regions are arranged one above the other.
Each of the first linear pipe portions in the first parallel arrangement portion and each of the second linear pipe portions in the second parallel arrangement portion are staggered up and down by shifting the front and rear positions by the first deviation amount. Lined up in
Each end of the plurality of first heat transfer tubes connected to the first through hole or the second through hole on one side in the front-rear direction from the second region, and the front and rear of the plurality of second heat transfer tubes. On one side of the direction, the first through hole or each end connected to the second through hole is staggered up and down by shifting the front and rear positions by the second deviation amount.
The front-rear distance between the pipe portions on one side of the plurality of second linear pipe portions in the front-rear direction is set to a second interval different from the first interval, so that the second deviation amount is larger than the first deviation amount. Heat exchanger for gas appliances that is larger. Of the plurality of first heat transfer tubes, each end connected to the first through hole or the second through hole on the side opposite to the one side in the front-rear direction from the first region, and the plurality of second transmissions. On the opposite side of the heat pipe, the first through hole or each end connected to the second through hole is staggered up and down by shifting the front and rear positions by a third deviation amount.
On the opposite side of the plurality of first linear tube portions, the front-rear interval between the tube portions is set to a third interval different from the first interval, so that the third deviation amount is larger than the first deviation amount. The heat exchanger for gas appliances according to claim 1, which is larger. A case with a peripheral wall that surrounds the exhaust gas passage space,
A heat transfer tube portion including a plurality of heat transfer tubes housed in the case,
It is a heat exchanger for gas appliances that has
The peripheral wall portion is provided with an exhaust gas discharge port on one side in the front-rear direction, an exhaust gas inflow port on the other side in the front-rear direction, and a side wall portion for attaching the heat transfer tube on one side in the left-right direction. ,
The side wall portion is provided with a first through hole group having a plurality of first through holes and a second through hole group having a plurality of second through holes, and the first through hole group and the second through hole group are provided. The holes are arranged apart from each other in the front-back direction.
Each of the plurality of heat transfer tubes is attached so that one end side corresponds to each of the first through holes of the first through hole group, and the other end side of each is attached to the second through hole of each of the second through hole groups. It is attached corresponding to the hole, and is fixed in multiple stages to the side wall portion in a configuration in which the positions in the vertical direction are shifted from each other.
The plurality of heat transfer tubes include a first heat transfer tube group including a plurality of first heat transfer tubes and a second heat transfer tube group including a plurality of second heat transfer tubes, and each of the first heat transfer tubes in the first heat transfer tube group. The first heat transfer tube and the second heat transfer tube in the second heat transfer tube group are alternately arranged in the vertical direction.
Each of the first heat transfer tubes includes a plurality of first linear tube portions that extend linearly from one side in the left-right direction to the other side.
The plurality of first linear pipe portions are arranged side by side from one side in the front-rear direction to the other side, and the front-rear distance between the pipe portions is equal at the first interval in the first region.
The first heat transfer tube group has a plurality of first parallel arrangement portions in which the first linear tube portions of each of the first regions are arranged one above the other.
Each of the second heat transfer tubes includes a plurality of second linear tube portions that extend linearly from one side in the left-right direction to the other side.
The plurality of the second linear pipe portions are arranged side by side from one side in the front-rear direction to the other side, and the front-rear distance between the pipe portions is equal to the first interval in the second region.
The second heat transfer tube group has a plurality of second parallel arrangement portions in which the second linear tube portions of each of the second regions are arranged one above the other.
Each of the first linear pipe portions in the first parallel arrangement portion and each of the second linear pipe portions in the second parallel arrangement portion are staggered up and down by shifting the front and rear positions by the first deviation amount. Lined up in
Each end of the plurality of first heat transfer tubes connected to the first through hole or the second through hole on one side in the front-rear direction, and the first of the plurality of second heat transfer tubes on one side in the front-rear direction. The through hole or each end connected to the second through hole is staggered up and down by shifting the front and rear positions by the second deviation amount.
In the second linear tube portion provided at one end of the plurality of second linear tube portions in the front-rear direction, the side connected to the first through hole or the second through hole is in the front-rear direction. A heat exchanger for gas appliances in which the second deviation amount is larger than the first deviation amount due to the formation of a bent interval expanding portion on one side. Each end of the plurality of first heat transfer tubes connected to the first through hole or the second through hole on the side opposite to one side in the front-rear direction, and the opposite side of the plurality of second heat transfer tubes. The first through hole or each end connected to the second through hole is staggered up and down by shifting the front and rear positions by the third deviation amount.
In the first linear tube portion provided at the opposite end of the plurality of first linear tube portions, the side connected to the first through hole or the second through hole is set to the opposite side. The heat exchanger for gas appliances according to claim 3, wherein the third deviation amount is larger than the first deviation amount due to the formation of another bent interval expanding portion. The heat exchanger for gas appliances according to any one of claims 1 to 4, wherein the plurality of heat transfer tubes each have a common shape. Each of the plurality of heat transfer tubes has a meandering shape and a non-rotational symmetric shape.
In the first heat transfer tube group, each of the plurality of first heat transfer tubes is arranged in every other step in the vertical direction.
In the second heat transfer tube group, each of the plurality of the second heat transfer tubes is arranged in every other step in the vertical direction.
The heat exchanger for gas appliances according to claim 5, wherein each of the plurality of second heat transfer tubes is arranged in a posture in which the posture of the first heat transfer tube is turned inside out.

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