JP5620685B2 - Heat exchanger - Google Patents

Description

  The present invention relates to a heat exchanger, and more particularly to a finless heat exchanger that recovers heat of exhaust gas by heat exchange between exhaust gas after combustion and a heat exchange medium.

  Conventionally, as this type of heat exchanger, cooling water is made to flow through a plurality of tubes formed in a U-shape, and substantially orthogonal to the cooling water in the plurality of tubes from the side close to the cooling water outlet of the plurality of tubes. In order to recover the heat of the exhaust gas so that the exhaust gas flows, there has been proposed (for example, see Non-Patent Document 1). In this heat exchanger, a plurality of tubes and the like are formed of stainless steel to prevent corrosion due to exhaust gas, and heat exchange efficiency is improved by inserting corrugated fins between the plurality of tubes.

Transactions of the Japan Society of Mechanical Engineers (B-biased), vol.72,713, pp. 96-103, 2006

  In a heat exchanger for recovering latent heat that recovers heat of exhaust gas, if the size is reduced, heat exchange efficiency may be reduced due to condensed water generated by heat exchange of exhaust gas. The heat exchanger is downsized by flattening the tubes and reducing the spacing between the tubes to increase the efficiency of heat exchange with the exhaust gas. This hinders the flow of exhaust gas and reduces the efficiency of heat exchange. Particularly in a heat exchanger in which fins are attached between tubes, in addition to a decrease in fin efficiency, the fins impede drainage of condensed water, and thus a decrease in heat exchange efficiency becomes significant.

  The main purpose of the heat exchanger of the present invention is to reduce the size of the heat exchanger and improve the efficiency of heat exchange in a latent heat recovery heat exchanger that recovers the heat of exhaust gas.

  The heat exchanger of the present invention employs the following means in order to achieve the main object described above.

The heat exchanger of the present invention is
A finless heat exchanger for recovering heat of the exhaust gas by heat exchange between the exhaust gas after combustion and the heat exchange medium,
Formed as a flat hollow tube with a metal plate material excellent in corrosion resistance against acid so that the thickness of the flow path of the heat exchange medium is 3 mm or less, and arranged in parallel so that the longitudinal direction is mainly the vertical direction with an interval of 3 mm or less A plurality of heat exchange tubes,
A shell that houses the plurality of heat exchange tubes and forms a flow path for circulating the exhaust gas between the plurality of heat exchange tubes;
With
The plurality of heat exchange tubes have an inlet for the heat exchange medium formed vertically downward and an outlet for the heat exchange medium formed vertically upward,
The shell is formed with the exhaust gas inlet formed vertically above and the exhaust gas outlet formed vertically below,
The plurality of heat exchange tubes and / or the shell are formed with meandering guide portions such that the exhaust gas meanders vertically from below to flow through the gaps between the plurality of heat exchange tubes.
This is the gist.

  In the heat exchanger of the present invention, a plurality of heat exchanging tubes formed as flat hollow tubes so that the thickness of the flow path of the heat exchanging medium is 3 mm or less by a metal plate having excellent corrosion resistance to acid is 3 mm or less. It arrange | positions in parallel so that a longitudinal direction may become a vertical direction mainly with a space | interval, and this arrange | positioned several heat exchange tube is accommodated in a shell. At this time, a flow path for circulating the exhaust gas is formed between the shell and the plurality of heat exchange tubes. The heat exchange medium inlet is formed vertically below the plurality of heat exchange tubes, the heat exchange medium outlet is formed vertically upward, and the exhaust gas inlet is formed vertically upward on the shell. An exhaust port for exhaust gas is formed. Then, a meandering guide portion is formed in one or both of the plurality of heat exchange tubes or shells so that the exhaust gas meanders vertically from below to flow through the gaps of the plurality of heat exchange tubes. In this way, a plurality of heat exchange tubes formed as flat hollow tubes so that the thickness of the flow path of the heat exchange medium is 3 mm or less are arranged in parallel at intervals of 3 mm or less, and these are stored in the shell. Therefore, a small heat exchanger can be obtained.

  In the heat exchanger of the present invention configured as described above, the heat exchange medium flows vertically from the inlet formed in the vertically lower side of the plurality of heat exchange tubes, and vertically moves the plurality of heat exchange tubes arranged in parallel. From the outflow port formed vertically above the plurality of heat exchange tubes. On the other hand, the exhaust gas flows from the inlet formed vertically above the shell, flows through the flow path formed between the shell and the plurality of heat exchange tubes, and flows from the outlet formed vertically below the shell. leak. In the flow path formed between the shell and the plurality of heat exchange tubes, the exhaust gas is meandered vertically upward from below by a meandering guide portion formed in one or both of the plurality of heat exchange tubes or shells. And flows into the gaps between the plurality of heat exchange tubes. Accordingly, the heat exchange medium flows vertically downward from above, and the exhaust gas meanders by the meandering guide portion, but as a whole it flows from vertically upward to vertically downward. Exchange efficiency will be improved. Condensed water is generated on the flat surfaces of the plurality of heat exchange tubes due to heat exchange of the exhaust gas, but the plurality of heat exchange tubes are arranged in parallel so that the longitudinal direction is mainly the vertical direction. Drained while collecting water. As a result, it is possible to suppress the generated condensed water from remaining and hinder the flow of the exhaust gas, and reduce the pressure loss of the exhaust gas. In addition, since the heat exchanger of the present invention is configured as a finless heat exchanger, it promotes drainage of condensed water as compared with a case where fins are attached between a plurality of heat exchange tubes. Can do. As a result, it is possible to provide a heat exchanger that is small in size and efficient in heat exchange.

  In the heat exchanger according to the present invention, the plurality of heat exchange tubes may be configured such that a vertical groove is formed at substantially the center of the flat surface. In this way, the condensed water generated on the flat surfaces of the plurality of heat exchange tubes flows vertically downward along the groove, so that the drainage of the condensed water can be improved, and heat that is more compact and efficient in heat exchange can be obtained. It can be an exchanger. Moreover, the strength of the plurality of heat exchange tubes can be improved by forming this groove. As a result, a plurality of heat exchange tubes can be formed using a thinner metal plate. In this case, the plurality of heat exchange tubes may be configured such that the grooves are bonded and fixed inside. In this way, the strength of the plurality of heat exchange tubes can be further improved.

  Further, in the heat exchanger according to the present invention, the meandering guide portion is a guide wall formed inside the shell so that the exhaust gas flows in a substantially horizontal direction with respect to the plurality of heat exchange tubes. You can also In this case, the meandering guide portion is a rib formed on the flat surface of the plurality of heat exchange tubes in the direction of the guide wall at a position aligned with the guide wall of the shell, in addition to the guide wall. It can also be. If it carries out like this, exhaust gas can be made to flow through the clearance gap between several tubes for heat exchange, meandering more reliably, and the efficiency of heat exchange can be improved.

  Furthermore, in the heat exchanger according to the present invention, the meandering guide portion is a plurality of ribs formed in a substantially horizontal direction on a flat surface of the plurality of heat exchange tubes, and the shell includes an outer wall. Of the plurality of heat exchanging tubes at a position where a plurality of ribs are formed, abuts against one side and the other side alternately from the uppermost side to the lower side, and both sides at the same level. It can also be formed so that it does not come into contact with a side surface different from the side surface with which the surface comes into contact. In this way, the plurality of ribs and shells formed on the flat surfaces of the plurality of heat exchange tubes allow the gaps between the plurality of heat exchange tubes while meandering the exhaust gas without forming a guide wall inside the shell. The efficiency of heat exchange can be improved.

  Alternatively, in the heat exchanger according to the present invention, the plurality of heat exchanging tubes are formed in a flat surface and a concave portion and a convex portion that are bent at an angle within a range of 10 degrees to 80 degrees with respect to a main flow direction of the exhaust gas. It is also possible to form a plurality of wavy uneven portions formed of a portion over substantially one surface. When the exhaust gas flows through the gaps between the plurality of heat exchange tubes, the exhaust gas flows along with the secondary flow by the plurality of wavy uneven portions formed on the flat surfaces of the plurality of heat exchange tubes. As a result, the heat exchange efficiency is improved. Moreover, since condensed water is guide | induced to the recessed part in a wavy uneven part by the flow of waste gas, the recessed part of a wavy uneven part plays a role of the drainage flow path of condensed water. That is, the drainage of condensed water can be improved by forming a plurality of wave-shaped uneven portions on the flat surfaces of a plurality of heat exchange tubes.

  In the heat exchanger of the present invention in which a plurality of wave-shaped uneven portions are formed on the flat surface of the plurality of heat exchange tubes, the plurality of heat exchange tubes are the wave-shaped unevenness at a portion located vertically above the flat surface. The angle of the portion with respect to the main flow direction of the exhaust gas is formed to be smaller than the angle with respect to the main flow direction of the exhaust gas of the wavy uneven portion in a portion located vertically below the flat surface. You can also. By reducing the angle of the corrugated irregularities in the part located vertically above the flat surface of the plurality of heat exchange tubes with respect to the main flow direction of the exhaust gas, the secondary flow of the exhaust gas is promoted, and the exhaust gas and the heat exchange medium The efficiency of heat exchange can be improved, and by increasing the angle of the wavy irregularities in the portion located vertically below the flat surface of the plurality of heat exchange tubes with respect to the main flow direction of the exhaust gas, The angle of the recess with respect to the vertical direction can be reduced to make it easier for the condensed water to flow vertically downward. In this case, the plurality of heat exchange tubes have a flat surface in which the angle of the wavy uneven portion at a portion located vertically above the flat surface with respect to the main flow direction of the exhaust gas is within a range of 10 degrees to 45 degrees. It is also possible that the angle of the wavy uneven portion at a portion located vertically below the main flow direction of the exhaust gas is within a range of 45 degrees to 80 degrees.

It is a block diagram which shows the outline of a structure of the heat exchanger 20 as one Example of this invention. It is a side view which shows the external appearance of the several tube 30 for heat exchange used for the heat exchanger 20 of an Example from the side. 4 is an enlarged explanatory view showing a part of a heat exchange tube 30 in an enlarged manner. FIG. It is explanatory drawing which shows typically the flow of the exhaust gas in the heat exchanger 20 of an Example. It is a block diagram which shows the outline of a structure of the heat exchanger 20B of a modification. It is a block diagram which shows the outline of a structure of 20 C of heat exchangers of a modification. It is a block diagram which shows the outline of a structure of heat exchanger 20D of a modification. It is a block diagram which shows the outline of a structure of the heat exchanger 20E of a modification. It is a block diagram which shows the outline of a structure of the tube 30F for heat exchange of a modification. It is a block diagram which shows the outline of a structure of the heat exchanger 20G of a modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a heat exchanger 20 as an embodiment of the present invention, and FIG. 2 is a side view of the appearance of a plurality of heat exchange tubes 30 used in the heat exchanger 20 of the embodiment. FIG. 3 is an enlarged explanatory view showing a part of the heat exchange tube 30 in an enlarged manner. The heat exchanger 20 according to the embodiment is configured as a finless heat exchanger that recovers the heat of exhaust gas by exchanging heat between the exhaust gas after combustion and a heat exchange medium such as cooling water. Is provided with a plurality of (for example, 22) heat exchange tubes 30 arranged in parallel so as to be in the vertical direction, and a shell 40 that houses the plurality of heat exchange tubes 30.

  Each of the heat exchange tubes 30 is a plate material having a thickness of 0.3 mm made of a metal material (for example, stainless steel) excellent in acid resistance to acid, and has a height (length) of 150 mm, a width of 30 mm, and an inner heat exchange medium. Is formed as a flat hollow tube having a substantially rectangular shape as a whole with a thickness of 2.4 mm (total thickness is 3.0 mm including the plate thickness). These are arranged in parallel so that the longitudinal direction is the vertical direction so that the gap is 1.6 mm. A heat exchange medium inlet 31 is formed in the vicinity of the lower end of each heat exchange tube 30 in the vertical direction, and each inlet 31 of each heat exchange tube 30 communicates with a communication pipe 31a. In addition, a heat exchange medium outlet 32 is formed in the vicinity of the upper upper end of each heat exchange tube 30 vertically, and each outlet 32 of each heat exchange tube 30 communicates with a communication pipe 32a. Therefore, the heat exchange medium flows in from each inlet 31 located vertically below each heat exchange tube 30, flows vertically through each heat exchange tube 30, and is located above each heat exchange tube 30 vertically. It flows out from each outflow port 32.

  As shown in FIGS. 1 and 3, a convex groove 36 is formed in the center of the flat surface of each heat exchange tube 30 with a vertical depth of 1.2 mm and a width of 1.6 mm. ing. Since the grooves 36 are formed on both flat surfaces of the heat exchanging tube 30, the grooves 36 of both flat surfaces abut on the inside of the tube. In the embodiment, the grooves 36 on both flat surfaces that are in contact with the inside of the tube are bonded and fixed by brazing or the like. Thereby, the intensity | strength of the tube 30 for heat exchange can be improved. Moreover, since this groove | channel 36 collects the condensed water which arises on the surface of the tube 30 for heat exchange by heat exchange with waste gas, and guides it vertically below, it can improve the drainage of condensed water.

  Further, the flat surface of each heat exchange tube 30 has a concave portion 33 having a shape in which a continuous “V” or “W” shape is bent by a predetermined angle α with respect to the horizontal and rotated by 90 degrees. And wavy rugged portions 33 and 34 each including a convex portion 34 are formed on the entire surface. The angle α from the horizontal of the wavy uneven portions 33 and 34 is in the range of 10 to 80 degrees, preferably in the range of 30 to 60 degrees, more preferably in the range of 30 to 45 degrees, and 30 in the embodiment. Degree. The wavy uneven portions 33 and 34 formed on the flat surface of each heat exchange tube 30 cause a secondary flow in addition to the main flow of the exhaust gas when the exhaust gas flows substantially horizontally. For this reason, the efficiency of heat exchange between the exhaust gas and the heat exchange medium can be improved. Moreover, since the wavy uneven portions 33 and 34 collect condensed water adhering to the flow of exhaust gas into the recessed portion 33 and guide it further vertically downward, it is possible to improve the drainage of the condensed water.

  As with each heat exchange tube 30, the shell 40 is made of a plurality of heat connected by connecting pipes 31 a and 32 a with a plate material having a thickness of 0.3 mm made of a metal material (for example, stainless steel) having excellent corrosion resistance against acid. It is formed as a substantially rectangular parallelepiped case that houses the replacement tube 30, and exhaust gas flow paths 46 a, 46 b, 46 c, 46 d are formed between the plurality of heat exchange tubes 30. An exhaust gas inlet 41 is formed on the left side in FIG. 1 vertically above the shell 40, and an exhaust gas outlet 42 is formed on the right side in FIG. Further, inside the shell 40, guide walls 43, 44 for separating the exhaust gas flow paths 46a, 46b, 46c, 46d formed between the plurality of heat exchange tubes 30 and guiding the flow of the exhaust gas are attached. It has been. Accordingly, the exhaust gas flows in from the inlet 41 formed vertically above the shell 40 as shown by the white arrow in FIG. 4, and the gaps between the heat exchange tubes 30 and the flow paths 46 a and 46 b while meandering. , 46c, 46d, and flows out from an outlet 42 formed vertically below the shell 40. Therefore, the exhaust gas and the heat exchange medium flowing through the plurality of heat exchange tubes 30 are opposed to each other as a whole, and the efficiency of heat exchange can be improved.

  According to the heat exchanger 20 of the embodiment described above, a plurality of substantially rectangular heat exchange tubes 30 formed as flat hollow tubes are arranged in parallel so that the longitudinal direction becomes the vertical direction with an interval of 1.6 mm. The heat exchange medium flows in from each inlet 31 located vertically below, flows each heat exchange tube 30 vertically upward, and flows from each outlet 32 located vertically above each heat exchange tube 30. On the other hand, exhaust gas flows in from an inlet 41 formed vertically above the shell 40, and flow paths 46a, 46b, formed by the shell 40, a plurality of heat exchange tubes 30, and guide walls 43, 44, 46c, 46d and the gaps between the plurality of heat exchanging tubes 30 are caused to meander and flow out of the outlet 42 formed vertically below the shell 40, whereby the exhaust gas and the plural heat exchanging tubes are flown. As counterflow as a whole heat exchange medium flowing through the 30, it is possible to improve the efficiency of heat exchange. By arranging the plurality of heat exchange tubes 30 in parallel so that the longitudinal direction is the vertical direction, the condensed water generated on the flat surfaces of the plurality of heat exchange tubes 30 by the heat exchange of the exhaust gas is collected vertically downward. It can be drained while. As a result, it is possible to suppress the generated condensed water from remaining and hinder the flow of the exhaust gas, and reduce the pressure loss of the exhaust gas. Moreover, since the heat exchanger 20 according to the embodiment is configured as a finless heat exchanger, the condensate drainage is promoted as compared with the case where fins are attached between the plurality of heat exchange tubes 30. Can do. As a result, it is possible to provide a heat exchanger that is small in size and efficient in heat exchange.

  Moreover, according to the heat exchanger 20 of an Example, by forming the groove | channel 36 of the perpendicular direction in the center of the flat surface of the several tube 30 for heat exchange, the flat surface of the tube 30 for heat exchange by heat exchange of waste gas. The condensate produced in the water can be collected and guided vertically downward, the drainage of the condensate can be improved, the strength of the plurality of heat exchange tubes 30 can be improved, and the thin plate thickness A plurality of heat exchange tubes 30 can be formed of a metal material, and a smaller heat exchanger can be obtained. In addition, the strength of the heat exchanging tube 30 can be further improved by bonding and fixing the groove 36 inside the tube.

  Furthermore, according to the heat exchanger 20 of an Example, the recessed part 33 and convex part which bend | fold and continue by the predetermined angle (alpha) with respect to the horizontal of the direction where an exhaust gas mainly flows to the flat surface of the several tube 30 for heat exchange. In addition to the main flow in the exhaust gas, a secondary flow can be generated, and as a result, the efficiency of heat exchange between the exhaust gas and the heat exchange medium can be improved. Can be improved. Moreover, since the wavy uneven portions 33 and 34 collect condensed water adhering to the flow of exhaust gas in the recessed portion 33 and guide it vertically downward, it is possible to further improve the drainage of the condensed water.

  In the heat exchanger 20 of the embodiment, the groove 36 is formed at the center of the flat surface of the plurality of heat exchange tubes 30 and the wavy uneven portions 33 and 34 are formed on substantially the entire flat surface. As shown in the heat exchanger 20B of this modification, the groove 36 is formed in the center of the flat surface of the plurality of heat exchange tubes 30B, but the wavy uneven portions 33 and 34 may not be formed on the flat surface. On the contrary, as shown in the heat exchanger 20C of the modification of FIG. 6, the groove 36 is not formed at the center of the flat surface of the plurality of heat exchange tubes 30C, but the wavy uneven portions 33C and 34C are formed on the flat surface. It is good also as what to do. In this case, the wavy uneven portions 33C and 34C may be formed at the center of the flat surface of the plurality of heat exchange tubes 30C. Alternatively, neither the groove 36 nor the wavy uneven portions 33 and 34 may be formed on the flat surfaces of the plurality of heat exchange tubes.

  In the heat exchanger 20 of the embodiment, the groove 36 is formed in the center of the flat surface of the plurality of heat exchange tubes 30 and the wavy uneven portions 33 and 34 are formed on substantially the entire flat surface. As shown in the heat exchanger 20D of the modified example, ribs 37a to 37d protruding outward may be formed at positions aligned with the flat guide walls 43 and 44 of the plurality of heat exchange tubes 30D. . By so doing, it is possible to more reliably induce exhaust gas meandering. In this case, it is preferable that the adjacent ribs 37a and 37b and the ribs 37c and 37d are separated by the groove 36. Thus, when forming a rib in the position which aligns with the flat guide walls 43 and 44 of several heat exchange tube 30D, as shown to the heat exchanger 20E of the modification of FIG. 8, several heat exchange is shown. Only the ribs 37a and 37d from the portion adjacent to the flat guide walls 43 and 44 of the tube 30E to the groove 36 may be formed.

  In the plurality of heat exchange tubes 30 of the heat exchanger 20 of the embodiment, the angle α from the horizontal of the wavy uneven portions 33 and 34 formed on the flat surface is set to 30 degrees, but is in the range of 10 degrees to 80 degrees. And preferably in the range of 30 to 60 degrees. Further, as shown in the heat exchanging tube 30F of the modification of FIG. 9, the wavy irregularities 33Fa and 34Fa located on the exhaust gas inflow side have a small angle α from the horizontal, and the wavy irregularities located on the exhaust gas outflow side. For the portions 33Fb and 34Fb, the angle β from the horizontal may be larger than the angle α. For example, the angle α is preferably 10 to 45 degrees, and the angle β is preferably 45 to 80 degrees. In the heat exchange tube 30F of the modification, 30 degrees was used for the angle α, and 60 degrees was used for the angle β. For this, for the wavy uneven portions 33Fa and 34Fa located on the exhaust gas inflow side, an angle α is set so as to improve the efficiency of heat exchange by promoting the secondary flow of the exhaust gas, and the wavy shape located on the exhaust gas outflow side. The uneven portions 33Fb and 34Fb are based on setting the angle β so as to promote the drainage of the condensed water downward. Accordingly, the wavy uneven portions 33 and 34 may be formed so that the angle from the horizontal increases stepwise or stepwise from the inflow side to the outflow side of the exhaust gas.

  In the heat exchanger 20 of the embodiment, the plurality of heat exchange tubes 30 are made of a stainless steel plate having a thickness of 0.3 mm, the height (length) is 150 mm, the width is 30 mm, and the flow path of the inner heat exchange medium The thickness of the tube is 2.4 mm (the overall thickness is 3.0 mm including the plate thickness) so as to form a substantially rectangular flat hollow tube as a whole, and there is a gap between the adjacent heat exchange tubes 30. Although arranged in parallel so that the longitudinal direction becomes the vertical direction so as to be 1.6 mm, any plate material may be used as long as it is a metal material having excellent corrosion resistance against acids other than stainless steel, and the thickness of the plate material is also strong. If it can hold | maintain, it may be thinner than 0.3 mm and may be thick. Further, the height, width, and thickness of the inner heat exchange medium flow path are not limited to 150 mm, 30 mm, and 2.4 mm, and any thickness may be used as long as the inner heat exchange medium flow path thickness is 3 mm or less. It may be the height width and the thickness of the flow path of the inner heat exchange medium. Further, the shape of the plurality of heat exchange tubes 30 may not be a substantially rectangular flat hollow tube, and may be, for example, an elliptical flat hollow tube. In addition, the gap between the adjacent heat exchange tubes 30 is not limited to 1.6 mm, and may be any interval as long as it is 3 mm or less. In addition, the plurality of heat exchange tubes 30 do not need to be arranged in parallel so that the longitudinal direction is accurately in the vertical direction, and may be arranged in parallel so that the longitudinal direction is in the vertical direction at a certain angle.

  In the heat exchanger 20 of the embodiment, the shell 40 is formed as a substantially rectangular parallelepiped case that houses a plurality of heat exchange tubes 30 by using a stainless steel plate having a thickness of 0.3 mm. However, the shell 40 is resistant to acids other than stainless steel. Any plate material may be used as long as it is a plate material made of an excellent metal material, and the thickness of the plate material may be less than 0.3 mm or thick as long as the strength can be maintained.

  In the heat exchanger 20 of the embodiment, the shell 40 is formed as a substantially rectangular parallelepiped case that houses the plurality of heat exchange tubes 30, and a plurality of exhaust gases meander while providing guide walls 43 and 44 inside thereof. Although it was made to flow through the clearance gap of the heat exchange tube 30 and the flow paths 46a, 46b, 46c, 46d, as shown in the heat exchanger 20G of the modification of FIG. 10, a plurality of ribs 37a to 37d are formed. The heat exchange tube 30D is used, and the shell 40G is formed on the side surface of the outer wall where the ribs 37a of the plurality of heat exchange tubes 30D are formed and the side surface where the ribs 37d of the plurality of heat exchange tubes 30D are formed. In order to come into contact, that is, the inside of the outer wall alternates from the top to the bottom of both side surfaces at the positions where the plurality of ribs 37a to 37d of the plurality of heat exchange tubes 30D are formed. The side surfaces (ribs 37a and 37d) that contact one side surface (the side surface at the position where the rib 37a is formed) and the other side surface (the side surface at the position where the rib 37d is formed) and abut on both sides in the same step. It is good also as what forms so that it may not contact | abut on the side surface (side surface in the position in which the ribs 37b and 37c were formed) different from the side surface in the position in which it was formed. In this way, the plurality of ribs 37a to 37d and the shell 40G formed on the flat surfaces of the plurality of heat exchange tubes 30D and the plurality of ribs 37a to 37d and a plurality of ribs meandering the exhaust gas without forming a guide wall inside the shell 40G. The heat exchange tube 30D can be passed through the gap, and the efficiency of heat exchange can be improved.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the heat exchanger manufacturing industry and the like.

  20, 20B-20E, 20G heat exchanger, 30, 30B-30F heat exchange tube, 31 inlet, 32 outlet, 31a, 32a contact officer, 33, 34, 33C, 34C, 33Fa, 34Fa, 33Fb, 34Fb Wavy uneven part (33 concave part, 34 convex part), 36 groove, 37a-37d rib, 40, 40G shell, 41 inlet, 42 outlet, 43,44 guide wall, 46a-46d flow path.

Claims (6)

A finless heat exchanger for recovering heat of the exhaust gas by heat exchange between the exhaust gas after combustion and the heat exchange medium,
Formed as a flat hollow tube with a metal plate material excellent in corrosion resistance against acid so that the thickness of the flow path of the heat exchange medium is 3 mm or less, and arranged in parallel so that the longitudinal direction is mainly the vertical direction with an interval of 3 mm or less A plurality of heat exchange tubes,
A shell that houses the plurality of heat exchange tubes and forms a flow path for circulating the exhaust gas between the plurality of heat exchange tubes;
With
The plurality of heat exchanging tubes have a vertical groove formed substantially in the center of the flat surface, and are bonded and fixed by the grooves facing inside, and an inlet of the heat exchange medium is vertically below. Since the outlet of the heat exchange medium is formed vertically upward, the heat exchange medium flows from vertically downward to vertically upward, and further on a flat surface with respect to the main flow direction of the exhaust gas. A plurality of wave-like irregularities composed of a concave portion and a convex portion which are bent and continuous in a shape in which a V-shape or a W-shape is rotated 90 degrees so as to intersect at an angle in the range of 80 degrees to 80 degrees. Formed ,
The shell is formed with the exhaust gas inlet formed vertically above and the exhaust gas outlet formed vertically below,
The plurality of heat exchange tubes and / or the shell are formed with meandering guide portions such that the exhaust gas meanders vertically from below to flow through the gaps between the plurality of heat exchange tubes.
Heat exchanger. The heat exchanger according to claim 1 ,
The meandering guide part is a guide wall formed inside the shell so that the exhaust gas flows in a substantially horizontal direction with respect to the plurality of heat exchange tubes.
Heat exchanger. The heat exchanger according to claim 2 ,
The meandering guide part is a rib formed on the flat surface of the plurality of heat exchange tubes in the direction of the guide wall at a position aligned with the guide wall of the shell, in addition to the guide wall.
Heat exchanger. The heat exchanger according to claim 1 ,
The meandering guide part is a plurality of ribs formed to have a plurality of steps in a substantially horizontal direction on the flat surface of the plurality of heat exchange tubes,
The shell is in contact with one side surface and the other side surface alternately from the top to the bottom of both side surfaces of the outer wall at the position where the plurality of ribs of the plurality of heat exchange tubes are formed. It is formed so as not to abut on the side surface different from the abutting side surface among both side surfaces in the same step,
Heat exchanger.
Heat exchanger. The heat exchanger according to claim 1 ,
The plurality of heat exchanging tubes include the wavy uneven portion in a portion where the angle of the wavy uneven portion in the portion located vertically above the flat surface with respect to the main flow direction of the exhaust gas is located vertically below the flat surface. Formed to be smaller than an angle with respect to the main flow direction of the exhaust gas.
Heat exchanger. The heat exchanger according to claim 5 ,
The plurality of heat exchanging tubes have an angle with respect to a main flow direction of the exhaust gas of the wavy uneven portion in a portion located vertically above the flat surface and vertically below the flat surface. Is formed so that an angle of the wavy uneven portion in a portion located in the main flow direction of the exhaust gas is within a range of 45 degrees to 80 degrees.
Heat exchanger.