Integrated heat exchanger and boiler

Abstract

An integrated heat exchanger according to the present invention may comprise: a housing having an intake unit and an exhaust unit through which combustion gas is introduced and discharged, and having therein a combustion gas transfer path connecting the intake unit to the exhaust unit; and a plurality of heat exchange units including a heat exchange pipe along which a fluid to be heated flows, and disposed at intervals in the combustion gas transfer path. The heat exchange units may comprise: a sensible heat exchange unit for sensible heat exchange; and a latent heat exchange unit for latent heat exchange.

Description

Integrated heat exchanger and boiler

[0001] The present invention relates to a heat exchanger and a boiler, and more specifically, to an integrated heat exchanger in which sensible heat exchange and latent heat exchange are combined in a single space, and a boiler including the same.

[0002] Generally, various types of boilers are installed in homes as a means of providing heating and hot water, and recently, condensing gas boilers, which can maximize thermal efficiency with minimal fuel consumption, are becoming increasingly popular.

[0003] A condensing gas boiler may typically be equipped with a sensible heat exchanger that performs sensible heat exchange by coming into contact with high-temperature combustion gas generated from a burner, and a latent heat exchanger that performs latent heat exchange by coming into contact with combustion gas that has passed through the sensible heat exchanger.

[0004] If sensible heat exchangers and latent heat exchangers are provided separately, difficulties may arise in the manufacturing process and manufacturing costs because they must maintain airtightness along with mechanical coupling.

[0005] The purpose of the present invention is to provide an integrated heat exchanger and boiler capable of resolving manufacturing process and cost issues in order to resolve the problems of the conventional technology described above.

[0006] In addition, the present invention also aims to provide an integrated heat exchanger and boiler that can improve heat exchange efficiency by ensuring sufficient contact between the heat exchange tube and the combustion gas, and can effectively prevent phenomena such as back-boiling caused by post-heating.

[0007] An integrated heat exchanger according to a preferred embodiment of the present invention for achieving the above-mentioned purpose may include: a housing having an intake section and an exhaust section through which combustion gas is introduced and discharged, and having a combustion gas transfer path inside that connects the intake section and the exhaust section; and a plurality of heat exchange sections arranged at intervals along the combustion gas transfer path, each including a heat exchange tube through which a fluid to be heated flows. The heat exchange sections may include a sensible heat exchange section where sensible heat exchange takes place, and a latent heat exchange section where latent heat exchange takes place.

[0008] The heat exchanger may further include a composite heat exchanger in which sensible heat exchange and latent heat exchange are performed together.

[0009] The sensible heat exchanger, the combined heat exchanger, and the latent heat exchanger can be arranged sequentially along the direction of combustion gas transport.

[0010] The combustion gas transport path may include a section with a decreasing cross-sectional area as it moves toward the exhaust section.

[0011] The combustion gas transport path may further include at least one cross-sectional area maintaining section in which the cross-sectional area is maintained.

[0012] The section with reduced cross-sectional area may be in the form where the cross-sectional area decreases as the width between the two sides of the housing narrows.

[0013] The portion constituting the section of reduced cross-sectional area among the two sides of the housing includes at least two inclined surfaces with different slopes, and the inclined surfaces may be formed consecutively.

[0014] The combustion gas conveying path is formed so that the combustion gas flows from the top to the bottom within the housing, and within it, a sensible heat exchanger, a combined heat exchanger, and a latent heat exchanger may be spaced apart from top to bottom.

[0015] The combustion gas transport path may include a sensible heat section comprising the entire sensible heat exchanger and a part of the combined heat exchanger, and a latent heat section comprising a part of the combined heat exchanger and the entire latent heat exchanger.

[0016] The heat exchanger includes first, second, third, and fourth heat exchangers arranged sequentially from top to bottom, wherein the first, second, and third heat exchangers have a structure in which a plurality of heat exchange tubes are arranged spaced apart from left to right and heat exchange fins are fitted spaced apart on the outer side of the heat exchange tubes, and the fourth heat exchanger may be composed only of a plurality of heat exchange tubes arranged spaced apart.

[0017] The diameter of the heat exchange tube constituting the fourth heat exchanger is smaller than the diameter of the heat exchange tube constituting the first, second, and third heat exchangers.

[0018] Sensible heat exchange is performed in the first heat exchanger, sensible heat exchange and latent heat exchange are performed together in the second heat exchanger, and latent heat exchange can be performed in the third and fourth heat exchangers.

[0019] The cross-sectional area of ​​the space where the first and second heat exchangers are placed is maintained constant, the cross-sectional area of ​​the space between the second heat exchanger and the fourth heat exchanger gradually decreases, and the cross-sectional area of ​​the space where the fourth heat exchanger is placed can be maintained constant.

[0020] Both sides of the housing may be symmetrical with respect to a virtual centerline passing vertically through the center of the combustion gas transport path.

[0021] Multiple heat exchange tubes constituting the fourth heat exchange section can be arranged in a convex arch shape toward the third heat exchange section.

[0022] The fourth heat exchanger has multiple heat exchange tubes arranged in two rows, upper and lower, and the number of heat exchangers in the lower row can be reduced compared to the number of heat exchange tubes in the upper row.

[0023] The number of heat exchange tubes constituting the first and second heat exchange sections is n, which is the same, and they are located on a virtual vertical line. The number of heat exchange tubes constituting the third heat exchange section is n-1, and they can be arranged on a virtual vertical line passing through the center between the heat exchange tubes constituting the second heat exchange section.

[0024] According to the integrated heat exchanger and boiler of the present invention, by integrally configuring a sensible heat exchanger that performs sensible heat exchange and a latent heat exchanger that performs latent heat exchange within a single heat exchanger housing, manufacturing process and cost issues can be resolved.

[0025] In addition, according to the present invention, the heat exchange efficiency of the heat exchanger can be improved by expanding the sensible heat section by additionally providing a composite heat exchanger in which sensible heat exchange and latent heat exchange are performed together, in addition to a sensible heat exchanger in which only sensible heat exchange is performed.

[0026] In addition, according to the present invention, by providing a cross-sectional area reduction section in which the cross-sectional area gradually decreases in the latent heat section where the temperature of the combustion gas is lower than in the sensible heat section, the flow of the combustion gas is guided toward the center, thereby improving the heat exchange efficiency between the combustion gas and the heat exchanger, and increasing the flow velocity of the combustion gas so that condensate can be easily discharged.

[0027] Furthermore, according to the present invention, the heat exchange section where the final heat exchange takes place within the heat exchanger housing is composed solely of a plurality of heat exchange tubes without heat exchange fins, and by forming gaps between the heat exchange tubes, the discharge of condensate generated in the latent heat section can be facilitated, and the contact area with the combustion gas can be increased, thereby improving heat exchange efficiency. In particular, by arranging the heat exchange tubes in an arch shape, the above-mentioned effects can be enhanced.

[0028] FIG. 1 is a perspective view showing a boiler according to a first embodiment of the present invention.

[0029] Figure 2 is a cross-sectional view showing the interior of the integrated heat exchanger and combustion chamber illustrated in Figure 1.

[0030] Figure 3 is a cross-sectional view showing the interior of the connection between the heat exchanger and the combustion chamber shown in Figure 2.

[0031] FIG. 4 is a perspective view of an integrated heat exchanger according to a first embodiment of the present invention.

[0032] Figure 5 is a cross-sectional view showing the interior of an integrated heat exchanger.

[0033] Figure 6 is a diagram showing the combustion gas flow in the sensible heat section.

[0034] Figure 7 is a longitudinal section showing the internal structure of the first heat exchanger tube.

[0035] Figure 8 is a front view of the first heat exchange fin.

[0036] FIG. 9 is a perspective view of the first heat exchange fin viewed from the rear.

[0037] FIG. 10 is a front view of the second heat exchange fin.

[0038] FIG. 11 is a perspective view of the second heat exchange fin viewed from the rear.

[0039] Figure 12 is a diagram showing the combustion gas flow in the latent heat section.

[0040] FIG. 13 is a front view of the third heat exchange fin.

[0041] FIG. 14 is a perspective view of the third heat exchange fin viewed from the rear.

[0042] FIG. 15 is a front view of the fourth heat exchange fin.

[0043] FIG. 16 is a perspective view of the fourth heat exchange fin viewed from the rear.

[0044] FIG. 17 is a cross-sectional view showing combustion gas being discharged through the exhaust passage and condensate being discharged through the condensate outlet.

[0045] FIG. 18 is an enlarged view showing the arrangement relationship between the side piping and the heat exchanger housing shown in FIG. 17.

[0046] FIG. 19 is a cross-sectional view showing the interior of an integrated heat exchanger according to a second embodiment of the present invention.

[0047] Figure 20 is a diagram showing the flow of combustion gases in the sensible heat section.

[0048] FIG. 21 is a cross-sectional view showing the internal structure of the first heat exchanger tube.

[0049] FIG. 22 is a front view of the first heat exchange fin.

[0050] FIG. 23 is a perspective view of the first heat exchange fin viewed from the rear.

[0051] FIG. 24 is a front view of the second heat exchange fin.

[0052] FIG. 25 is a perspective view of the second heat exchange fin viewed from the rear.

[0053] FIG. 26 is a cross-sectional view showing the interior of an integrated heat exchanger according to a third embodiment of the present invention.

[0054] Figure 27 is a diagram showing the flow of combustion gases in the sensible heat section.

[0055] FIG. 28 is a cross-sectional view showing the internal structure of the first heat exchanger tube.

[0056] FIG. 29 is a front view of the first heat exchange fin.

[0057] FIG. 30 is a perspective view of the first heat exchange fin viewed from the rear.

[0058] FIG. 31 is a front view of the second heat exchange fin.

[0059] FIG. 32 is a perspective view of the second heat exchange fin viewed from the rear.

[0060] Figure 33 is a diagram showing the combustion gas flow in the latent heat section.

[0061] FIG. 34 is an enlarged view of the second latent heat exchanger of FIG. 33.

[0062] Hereinafter, an integrated heat exchanger and a boiler according to preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0063]

[0064] FIG. 1 is a perspective view showing a boiler according to a first embodiment of the present invention. FIG. 1 shows the devices located inside the boiler case with the boiler case removed.

[0065] A boiler according to the present invention includes a heat exchanger (100), an intake fan (200), a gas inlet (300), an air inlet (400), and an exhaust passage (500).

[0066] The heat exchanger (100) is an integrated heat exchanger that heats a fluid to be heated using sensible heat and latent heat generated when burning gas. By installing heat exchange tubes through which a fluid to be heated, such as water, flows in a passage through which combustion gas generated by the combustion of gas travels, the heat possessed by the combustion gas is transferred to the fluid to be heated through the heat exchange tubes during the process of the combustion gas traveling, thereby heating the fluid to be heated. A combustion chamber, which will be described later, where the combustion of gas takes place, may be provided at the top of the heat exchanger (100).

[0067] An intake fan (200) is provided outside the heat exchanger (100) and can supply gas and air into the combustion chamber from the outside. The intake fan (200) can be connected to a gas inlet (300) for gas intake and an air inlet (400) for air intake.

[0068] The exhaust passage (500) is a passage for discharging combustion gas passing through the heat exchanger (100) to the outside and is installed on the side of the heat exchanger (100). The inlet of the exhaust passage (500) is connected to the lower part of the heat exchanger (100), and the outlet can be opened toward the top of the boiler.

[0069]

[0070] Figure 2 is a cross-sectional view showing the interior of the integrated heat exchanger and combustion chamber illustrated in Figure 1.

[0071] In the case of the boiler according to the present invention, a combustion chamber (700) equipped with a burner (600) is provided above the heat exchanger (100), and an exhaust passage (500) is connected to the lower part of the heat exchanger (100) to discharge combustion gas passing through the heat exchanger (100) to the outside.

[0072] The combustion gas generated during gas combustion in the combustion chamber (700) is introduced through the upper part of the heat exchanger (100), then moves downward within the heat exchanger (100) to heat the fluid to be heated, and is discharged to the outside through the exhaust passage (500) connected to the lower part of the heat exchanger (100).

[0073] In the upper part of the internal space of the heat exchanger (100) connected to the combustion chamber (700), heat exchange by sensible heat takes place, and in the lower part relatively far from the combustion chamber (700), heat exchange by latent heat takes place. Condensation occurs in the part where latent heat exchange takes place, and the generated condensation collects at the bottom of the exhaust passage (500) and is discharged to the outside through the condensate discharge port described later.

[0074] The exhaust passage (500) is provided below and to the side of the heat exchanger (100) and connected to the open bottom of the heat exchanger (100), forming a passage for the discharge of combustion gas passing through the heat exchanger (100). One end of the exhaust passage (500) is connected to the bottom of the heat exchanger (100), and the other end of the exhaust passage (500) is opened to the outside from the top of the boiler.

[0075] In order to improve heat exchange performance within the heat exchanger (100), the flow of combustion gas within the heat exchanger (100) must be smooth and the contact between the combustion gas and the heat exchange tube must be concentrated. In addition, to improve heat exchange performance within the heat exchanger (100), the discharge of combustion gas through the exhaust passage (500) must also be smooth.

[0076] Accordingly, the boiler according to the present invention has improved the above technical features necessary to improve heat exchange performance, and the features will be described in detail below.

[0077]

[0078] Figure 3 is a cross-sectional view showing the interior of the connection between the heat exchanger and the combustion chamber shown in Figure 2.

[0079] The heat exchange tubes (p) are arranged to pass through the inside of the heat exchanger (100) and the side outer side of the combustion chamber (700), and the heat exchange tubes (p) are connected in series or parallel with neighboring ones on the front and back plates that shield the front and back of the heat exchanger (100) and the front and back of the combustion chamber (700). Through this connection structure, the multiple heat exchange tubes (p) form a passage for the heated fluid through which the heated fluid flows.

[0080] The inlet of the fluid to be heated passage is located on the lower side of the heat exchanger (100), and the outlet of the fluid to be heated passage may be located on the upper side of the combustion chamber (700). Accordingly, the fluid to be heated flowing in from the outside passes from the lower side of the heat exchanger (100) through the upper side, then passes from the lower side of the combustion chamber (700) through the upper side, and is discharged to the outside. The fluid to be heated having this flow is heated at a higher temperature as it moves from the inlet side to the outlet side.

[0081] In FIG. 3, multiple heat exchange tubes are connected in series or parallel to form a single passage for the fluid to be heated, so the drawing symbols for the heat exchange tubes are all assigned the same symbol 'p'. In subsequent drawings, the drawing symbols for the heat exchange tubes will be assigned differently for each region.

[0082] The open bottom of the combustion chamber (700) is connected to the open top of the heat exchanger (100), and combustion of gas takes place in the burner (600) provided at the top of the combustion chamber (700), and the combustion gas is sent from the combustion chamber (700) to the heat exchanger (100), passes through the inside of the heat exchanger (100) from top to bottom, and is discharged to the outside.

[0083] The internal temperature gradually decreases as it goes from the top of the combustion chamber (700) to the bottom of the heat exchanger (100). The temperature of the fluid to be heated flowing from the outside into the bottom of the heat exchanger (100) rises as it passes through the heat exchanger (100) from the bottom to the top, and the temperature rises further as it passes through the combustion chamber (700) from the bottom to the top.

[0084] A first flange portion (111) horizontally extending outward is formed at the upper opening of the heat exchanger housing (110) constituting the heat exchanger (100), and a second flange portion (711) horizontally extending outward is formed at the lower opening of the combustion chamber housing (710) constituting the combustion chamber (700). The first and second flange portions (111) and (711) are brazed together in a butt-together state.

[0085] Deformation-preventing ribs (112) are formed on both sides of the heat exchanger housing (110) by being bent outward to prevent deformation of the heat exchanger (100). The deformation-preventing ribs (112) are formed in a shape that protrudes outward from the sides of the heat exchanger housing (110). A clearance space connected to the interior of the heat exchanger housing (110) is formed on the inner side of the deformation-preventing ribs (112). The deformation-preventing ribs (112) of this structure prevent deformation of the heat exchanger housing (110) by reinforcing the strength of the heat exchanger housing (110).

[0086] On the outer sides of both sides of the combustion chamber housing (710), a heat exchange tube insertion groove (712) into which a heat exchange tube (p) is inserted from the outer direction is formed so as to be open to the outside of the combustion chamber housing (710). The portion where the heat exchange tube insertion groove (712) is formed protrudes into the combustion chamber (700). Accordingly, the heat exchange tube (p) is provided in a form in which a portion of it is embedded in the side of the combustion chamber (700) from the outside of the combustion chamber (700).

[0087] An insulating material (800) may be provided on the inner side of the connection between the combustion chamber housing (710) and the heat exchanger housing (110). The lower end of the insulating material (800) is fitted and fixed to the edge of the first heat exchanger fin, which will be described later, and the upper end of the insulating material (800) is pressed and fixed to the inner side of the connection between the combustion chamber housing (710) and the heat exchanger housing (110) by an insulating material fixing means (900). Through this fixing structure, the insulating material (800) can be in close contact with the inner side of the connection between the combustion chamber housing (710) and the heat exchanger housing (110).

[0088] The insulation fixing means (900) is provided on the inner side of the lower part of the combustion chamber housing (710) to press the upper part of the insulation (800), and may be composed of a metal plate. The insulation fixing means (900) is bent to correspond to the shape of the inner surface of the combustion chamber housing (710) and may have its own elasticity due to the bent structure. The upper part of the insulation fixing means (900) is joined to the inner surface of the combustion chamber housing (710) by brazing, and the lower part of the insulation fixing means (900) is separated without being joined to the inner surface of the combustion chamber housing (710). Accordingly, the lower part of the insulation fixing means (900) presses the insulation (800) against the inner side of the connection between the combustion chamber housing (710) and the heat exchanger housing (110).

[0089]

[0090] FIG. 4 is a perspective view of an integrated heat exchanger according to a first embodiment of the present invention, and FIG. 5 is a cross-sectional view showing the interior of the integrated heat exchanger.

[0091] According to the integrated heat exchanger (100) of the present invention, a sensible heat section (120) where sensible heat exchange takes place and a latent heat section (130) where latent heat exchange takes place can be formed vertically within the internal space of the heat exchanger housing (110). A plurality of heat exchange sections (140)(150)(160)(170) are arranged within the internal space of the heat exchanger housing (110).

[0092] The heat exchanger housing (110) forms a combustion gas transport path through which combustion gas moves within the internal space, forms an intake section (113) connected to the combustion chamber (700) at the top, and forms an exhaust section (114) connected to the exhaust passage (500) at the bottom. Through the combustion gas transport path, the combustion gas moves from the top to the bottom.

[0093] The heat exchange section (140)(150)(160)(170) includes a sensible heat exchange section (140) in which only sensible heat exchange occurs, a combined heat exchange section (150) in which sensible heat exchange and latent heat exchange occur together, and a latent heat exchange section (160)(170) in which only latent heat exchange occurs. The sensible heat exchange section (140), the combined heat exchange section (150), and the latent heat exchange section (160)(170) are arranged in multiple stages with a gap from top to bottom. FIG. 5 shows the sensible heat exchange section (140) and the combined heat exchange section (150) each configured as one stage, and the latent heat exchange section (160)(170) configured as two stages.

[0094] The sensible heat exchanger (140) is located in the sensible heat section (120), and the upper part of the composite heat exchanger (150) is located in the sensible heat section (120) and the lower part is located in the latent heat section (130). The latent heat exchangers (160) (170) are all located in the latent heat section (130).

[0095] When looking at the temperature distribution of combustion gas in the heat exchanger (100) and the combustion chamber (700), the temperature of the combustion chamber is at a high temperature of 1000°C or higher, and the temperature between the sensible heat exchanger (140) and the composite heat exchanger (150) is about 300°C. That is, the upper part of the sensible heat exchanger (140) is about 1000°C and the lower part is about 300°C, which is a very high temperature, and there is a significant temperature difference between the upper and lower parts of the sensible heat exchanger (140).

[0096] In the case of the heat exchanger (100), it can be observed that the temperature of the combustion gas tends to decrease as it goes from the top to the bottom, that is, from the sensible heat section (120) to the latent heat section (130).

[0097] Considering this temperature distribution, the cross-sectional area of ​​the combustion gas transport path can be formed differently as it extends downward. That is, the cross-sectional area of ​​the combustion gas transport path where the latent heat section (130) is located can be formed narrower than the cross-sectional area of ​​the combustion gas transport path where the sensible heat section (120) is located. In other words, since the temperature of the combustion gas is high in the sensible heat section (120), the target heat exchange performance can be obtained even if the cross-sectional area of ​​the sensible heat section (120) is relatively wide. However, since the temperature of the combustion gas is low in the latent heat section (130), the heat exchange performance may decrease if the cross-sectional area of ​​the latent heat section (130) is wide, so the heat exchange performance can be improved by making the cross-sectional area relatively narrow.

[0098] In response to this change in cross-sectional area, as shown in FIG. 5, the number of heat exchange tubes constituting each stage of the latent heat exchanger (160)(170) is reduced compared to the number of heat exchange tubes to be described later constituting each stage of the sensible heat exchanger (140) and the composite heat exchanger (150). Instead of reducing the number of heat exchange tubes constituting the latent heat exchanger (160)(170), the latent heat exchanger (160)(170) is configured in multiple stages, thereby allowing the heat of the combustion gas to be absorbed efficiently. The cross-sectional area of ​​the heat exchanger housing (110) can be changed by varying the width between the left side and the right side while maintaining the front-to-back width of the heat exchanger housing (110) constant.

[0099] For reference, the fluid to be heated flows from the outside into the latent heat exchanger (170) located at the bottom end, then passes through the upper latent heat exchanger (160), the composite heat exchanger (150), and the sensible heat exchanger (140) in sequence, then passes through the combustion chamber (700) and is discharged to the outside.

[0100] Meanwhile, as shown in FIG. 5, the gap (L2) between the composite heat exchanger (150) and the upper latent heat exchanger (160) can be formed wider than the gap (L1) between the sensible heat exchanger (140) and the composite heat exchanger (150). That is, L1 < L2.

[0101] In this way, the gap (L1) between the sensible heat exchanger (140) and the combined heat exchanger (150) is formed to be relatively short so that high-temperature combustion gas can pass through the sensible heat exchanger (140) and approach the combined heat exchanger (150) at a rapid speed, since no condensation occurs in the sensible heat section (120).

[0102] On the other hand, since the latent heat section (130) is a section where condensation occurs, it is necessary to make the distance between the upper heat exchanger and the lower heat exchanger relatively far in this section to prevent condensation from forming between the two heat exchangers during the process of falling. That is, if the distance between the upper heat exchanger and the lower heat exchanger is close, condensation may form between the heat exchanger pins, which will be described later and constitute the upper heat exchanger, and the heat exchanger pins that constitute the lower heat exchanger, which can reduce heat exchange performance.

[0103] Thus, the heat exchanger (100) according to the present invention can be expected to have the effect of rapidly separating and removing condensate from the heat exchange section by forming a different distance between the upper and lower heat exchange sections. That is, a structure that rapidly separates and removes condensate by adjusting the gap between the heat exchange sections can be applied as an example of a condensate separation and discharge structure.

[0104]

[0105] FIG. 6 is a drawing showing the combustion gas flow in the sensible heat section, FIG. 7 is a longitudinal section showing the internal structure of the first heat exchanger tube, FIG. 8 is a front view of the first heat exchanger fin, FIG. 9 is a perspective view of the first heat exchanger fin viewed from the rear, FIG. 10 is a front view of the second heat exchanger fin, and FIG. 11 is a perspective view of the second heat exchanger fin viewed from the rear.

[0106] The sensible heat exchanger (140) includes a plurality of first heat exchange tubes (141) and a plurality of first heat exchange fins (142) surrounding the first heat exchange tubes (141). In the drawing, four first heat exchange tubes (141) are arranged side by side with spacing, and a plurality of first heat exchange fins (142) are arranged with spacing in the front-rear direction. A plurality of first through holes (142a) through which the first heat exchange tubes (141) pass are formed spaced apart in the first heat exchange fins (142), and the first heat exchange tubes (141) and the first heat exchange fins (142) are joined by a brazing method while the first heat exchange fins (142) are fitted into the first heat exchange tubes (141).

[0107] Combustion gas introduced through the upper intake section (113) of the heat exchanger housing (110) moves downward through the gap between the first heat exchanger tube (141) and the first heat exchanger fin (142) and the first heat exchanger fin (142), thereby heating the fluid to be heated through the first heat exchanger tube (141) and the first heat exchanger fin (142).

[0108] A first heat exchange groove (142b) that is open upward is deeply formed between the first heat exchange fin (142) and the first through hole (142a). It is preferable that the depth of the first heat exchange groove (142b) be formed lower than the center of the first heat exchange tube (141). Through this, in the part of the first heat exchange fin (142) where the first heat exchange groove (142b) is formed, the portion surrounding the first heat exchange tube (141) is formed as a curved surface having the same curvature as the first heat exchange tube (141), and by being formed as a uniform area, the heat of the combustion gas can be transferred uniformly and quickly to the surface of the first heat exchange tube (141). Therefore, the heat transfer performance to the first heat exchange tube (141) can be improved, and boiling noise can be prevented. If the first heat exchange groove (142b) is not formed in the first heat exchange fin (142), heat is excessively transferred only to the upper side of the first heat exchange tube (141), and boiling noise may occur.

[0109] At the bottom of the first heat exchange fin (142), a plurality of bending portions (142c) are formed spaced apart from each other on the left and right sides. The bending portions (142c) are formed to protrude from the rear of the first heat exchange fin (142) by bending, are located between the first through holes (142a), and are located below the first heat exchange groove (142b). Accordingly, combustion gas passing through the first heat exchange tube (141) collides with the bending portions (142c) and becomes stagnant, thereby extending the heat exchange time between the combustion gas and the first heat exchange tube (141), which can improve heat exchange efficiency. That is, since the sensible heat exchange portion (140) is the place that receives the highest heat among the heat exchange portions (140~170) and heats the fluid to be heated inside the heat exchange tube, by providing bending portions (142c) capable of trapping heat, the fluid to be heated can be effectively heated.

[0110] Meanwhile, on both sides of the upper portion of the first heat exchange fin (142), an insulation material fitting groove (142d) is formed, into which an insulation material (800) is fitted between the inner surface of the heat exchanger housing (110).

[0111] The combustion gas is dispersed to both sides of the bending section (142c) and then descends through the bending section (142c).

[0112] A filler material injection hole (142e) may be formed connected to the first through hole (142a) at the lower circumference of the first through hole (142a) to allow the filler material to easily seep between the first heat exchange fins (142) and the first heat exchange tube (141) when brazing the first heat exchange fins (142) and the first heat exchange tube (141).

[0113] In the case of the composite heat exchanger (150) and latent heat exchanger (160)(170), a filler material injection hole, such as the filler material injection hole (142e) of the first heat exchanger fin (142), is formed in each, thereby allowing the filler material to easily seep between the heat exchanger fin and the heat exchanger tube.

[0114] A bending contact portion (142f) is formed around the circumference of the first through hole (142a), which is bent backward to contact the outer surface of the first heat exchange tube (141). Additionally, bending contact portions (142g) are formed on both ends of the first heat exchange fin (142), which are bent backward to contact the inner surface of the heat exchanger housing (110).

[0115] The interior of the first heat exchange tube (141) is separated into upper and lower spaces by a partition (141a), and communication holes (141b) that connect the upper and lower spaces are spaced apart and formed in the partition (141a), and inclined surfaces (141c) that are inclined upward and downward relative to the partition (141a) may be alternately formed around the communication holes (141b). The inclined surfaces (141c) are formed at an angle in the direction in which the fluid to be heated flows, so that the fluid to be heated flowing along the upper space of the partition (141a) may mix with the lower space, and the fluid to be heated flowing along the lower space may mix with the upper space. Through this turbulence generation structure, the fluid to be heated flowing inside the first heat exchange tube (141) can be heated uniformly, and boiling noise can be reduced together with the first heat exchange groove (142b). In particular, since the temperature of the combustion gas passing through the sensible heat exchanger (140) is high, the heat exchange efficiency can be further increased by evenly mixing the fluid to be heated flowing through the first heat exchanger tube (141) as described above.

[0116] The composite heat exchanger (150) includes a plurality of second heat exchange tubes (151) and a plurality of second heat exchange fins (152) surrounding the second heat exchange tubes (151). In the drawing, four second heat exchange tubes (151) are arranged side by side with spacing, and the second heat exchange fins (152) are arranged with spacing in the front-rear direction. A plurality of second through holes (152a) through which the second heat exchange tubes (151) pass are formed spaced apart from side to side in the second heat exchange fins (152), and the second heat exchange tubes (151) and the second heat exchange fins (152) can be joined by a brazing method while the second heat exchange tubes (151) are fitted with the second heat exchange fins (152).

[0117] The number of second heat exchange tubes (151) constituting the composite heat exchanger (150) can be configured to be the same as the number of first heat exchange tubes (141) constituting the sensible heat exchanger (140). Additionally, the first heat exchange tubes (141) can be located vertically above the second heat exchange tubes (151). That is, the first and second heat exchange tubes (141) (151) are arranged side by side from left to right, and the centers of the nth ones located relative to the first and second heat exchange tubes (141) (151) at the left end can be located on the same vertical line.

[0118] In the case of the second heat exchange fins (152) constituting the composite heat exchanger (150), second heat exchange grooves (152b) having the same function as the first heat exchange groove (22b) formed in the first heat exchange fins (142) can be formed. That is, the heat of the combustion gas passing through the sensible heat exchanger (140) can be transferred uniformly and quickly to the surface of the second heat exchange tube (151). However, the depth of the second heat exchange groove (152b) can be formed shallower than the depth of the first heat exchange groove (142b).

[0119] The bending portions (142c) formed at the bottom of the first heat exchange fins (142) are positioned between adjacent first heat exchange tubes (141) as described above, as well as above between adjacent second heat exchange tubes (151). The horizontal length of the bending portions (142c) is formed to be shorter than the distance between the centers of adjacent second heat exchange tubes (151). Accordingly, the space between the bending portions (142c) is positioned above the center of the second heat exchange tube (151), so that the combustion gas passing through the sensible heat exchange portion (140) is transferred to the upper part of the second heat exchange tube (151), then branches out to both sides of the second heat exchange tube (151) and passes through the composite heat exchange portion (150) in a form that surrounds the second heat exchange tube (151). In particular, since the combustion gas and the second heat exchange tube (151) come into rapid and uniform contact through the second heat exchange groove (152b), the fluid to be heated flowing through the second heat exchange tube (151) can be heated rapidly and uniformly.

[0120] As described above, the heat exchange efficiency in the sensible heat exchanger (140) and the composite heat exchanger (150) can be improved through a structure in which the first heat exchanger (141) and the second heat exchanger (151) are provided in equal numbers, the positions of the two heat exchanger tubes arranged vertically are located on the same vertical line, the first heat exchanger fin (142) has a first heat exchanger groove (142b) and a bending portion (142c) formed therein, and the second heat exchanger fin (152) has a second heat exchanger groove (152b) formed therein. Additionally, as described above, since the distance between the sensible heat exchanger (140) and the composite heat exchanger (150) is relatively shorter than the distance between the heat exchanger sections below them, the composite heat exchanger (150) can be closer to the burner (600). By utilizing these structures, sensible heat exchange can also be performed in the composite heat exchanger (150).

[0121] However, due to the temperature distribution of the combustion gas, it is difficult for sensible heat exchange to occur throughout the entire composite heat exchanger (150), and latent heat exchange may occur in the lower part of the composite heat exchanger (150). Through the structure of the sensible heat exchanger (140) and the composite heat exchanger (150) as described above, the sensible heat section (120) formed in the composite heat exchanger (150) can be formed relatively larger than the latent heat section (130). Therefore, the heat exchange efficiency in the composite heat exchanger (150) can be improved.

[0122] The ranges of the temperature of the combustion chamber (700) where the burner (600) is located, the temperature in the sensible heat section (120), the temperature in the latent heat section (130), and the combustion gas exhaust temperature are not freely changeable because they are specified in the certified boiler. Therefore, it is important to maximize heat exchange efficiency within the specified range, and to this end, in the present invention, not only the uppermost sensible heat exchanger (140) but also the second-stage composite heat exchanger (150) are included in the sensible heat section (120) so as to be used for sensible heat exchange.

[0123] In the center between the second heat exchange fin (152) and the second through hole (152a), that is, between the two second heat exchange tubes (151) arranged side by side on the left and right, a first central guide (152c) is protruded by bending to the rear of the second heat exchange fin (152) as a central guide means to guide the flow of combustion gas to concentrate on the second heat exchange tube (151). The first central guide (152c) is located below the second heat exchange groove (152b).

[0124] Since the composite heat exchanger (150) heats the fluid to be heated at a temperature higher than that of the sensible heat exchanger (140), it is desirable for the composite heat exchanger (150) to have a structure capable of trapping heat, that is, a structure capable of stagnating the flow of combustion gas, just as in the sensible heat exchanger (140). However, since the lower temperature of the composite heat exchanger (150) is about 70°C, the structure that traps heat may be configured to hinder the discharge of condensate. Therefore, in the present invention, the combustion gas flowing between the second heat exchanger tubes (151) is made to adhere as closely as possible to the second heat exchanger tubes (151) through the first central guide (152c).

[0125] Specifically, the first central guide (152c) is positioned below the center of the two second heat exchange tubes (21) and is formed to slope downward diagonally toward the second heat exchange tubes (21) as it goes from the center to both ends, so that the distance between the ends widens as it goes toward the ends. The height at which the first central guide (152c) is formed is located between the center and the bottom of the second heat exchange tube (151). Both ends of the first central guide (152c) are each formed as left-right symmetrical inclined surfaces and guide the flow of combustion gas passing between the second heat exchange tubes (151) so that it flows while in close contact with the second heat exchange tubes (151). Through this, the time that the combustion gas is in contact with the second heat exchange tube (151) is extended, so the fluid to be heated flowing through the second heat exchange tube (151) can be effectively heated.

[0126] In addition, because the space between the second heat exchange tube (151) and the first central guide (152c) is narrow, the combustion gas moves at a high speed, allowing the condensate formed on the lower part of the second heat exchange fin (152) to be easily dropped and discharged. Meanwhile, the ends of both ends of the first central guide (152c) may be the point at which condensate is generated, that is, the point at which the latent heat section begins. If the ends of both ends of the first central guide (152c) are above the point at which condensate is generated, the combustion gas cannot flow closely to the lower part of the second heat exchange tube (151), and conversely, if the ends of the first central guide (152c) are below the point at which condensate is generated, it is difficult to send the condensate with the combustion gas, which may cause a problem with condensate discharge.

[0127] As described above, the cross-sectional area of ​​the combustion gas transport path where the latent heat section (130) is located is formed to be narrower than the cross-sectional area of ​​the combustion gas transport path where the sensible heat section (120) is located. That is, since the width of the heat exchanger housing (110) narrows as it goes downward in the latent heat section (130), the velocity of the combustion gas also increases. The point at which the width begins to narrow can be the point at which condensate is generated, that is, the point at which the latent heat section (130) begins. The lower part of the second heat exchange fin (152) is located at the part where the latent heat section (130) begins, and both sides of the second heat exchange fin (152) are also formed in a shape where the width narrows as it goes downward. Accordingly, if the point where the latent heat section (130) begins is virtually indicated by a horizontal line, the point where the width of the heat exchanger housing (110) narrows, the point where the width of the second heat exchange fin (152) narrows, and the ends of both sides of the first central guide (152c) are positioned side by side on the virtual horizontal line.

[0128] A bending contact portion (152d) is formed around the circumference of the second through hole (152a), which is bent backward to contact the outer surface of the second heat exchange tube (151). Additionally, bending contact portions (152e) are formed on both ends of the second heat exchange fin (152), which are bent backward to contact the inner surface of the heat exchanger housing (110).

[0129] Looking at the flow of combustion gas in FIG. 6, it can be seen that the combustion gas flows in a concentrated manner, wrapping around the first heat exchange tube (141) and the second heat exchange tube (151), due to the bending portion (142c) formed on the first heat exchange plate (142) and the first central guide (152c) formed on the second heat exchange plate (152).

[0130] Meanwhile, a circular hole (152f) is formed in the lower part of the first central guide (152c) of the second heat exchange fin (152). This circular hole (152f) reduces the area of ​​the portion located below the first central guide (152c) of the second heat exchange fin (152), that is, the area of ​​the portion located in the latent heat section (130), thereby reducing the area where condensation forms. Therefore, even if condensation forms on the lower part of the second heat exchange fin (152), the contact area between the condensation and the second heat exchange fin (152) is reduced, making it easier to discharge the condensation.

[0131]

[0132] FIG. 12 is a diagram showing the combustion gas flow in the latent heat section, FIG. 13 is a front view of the third heat exchange fin, FIG. 14 is a perspective view of the third heat exchange fin viewed from the rear, FIG. 15 is a front view of the fourth heat exchange fin, and FIG. 16 is a perspective view of the fourth heat exchange fin viewed from the rear.

[0133] The composite heat exchanger (150) is positioned at the boundary between the sensible heat section (120) and the latent heat section (130). The upper part of the composite heat exchanger (150) is included in the sensible heat section (120), and the lower part is included in the latent heat section (130).

[0134] The latent heat exchanger (160)(170) is configured in two upper and lower sections. The first latent heat exchanger (160) located at the top includes a plurality of third heat exchange tubes (161) and a plurality of third heat exchange fins (162) surrounding them. The second latent heat exchanger (170) located at the bottom includes a plurality of fourth heat exchange tubes (171) and a plurality of fourth heat exchange fins (172) surrounding them.

[0135] The third heat exchange tubes (161) are arranged side by side at intervals, and the third heat exchange fins (162) are arranged at intervals in the front-rear direction. Several third through holes (162a) through which the third heat exchange tubes (161) pass are formed at intervals in the third heat exchange fins (162). With the third heat exchange fins (162) inserted into the third heat exchange tubes (161), the third heat exchange tubes (161) and the third heat exchange fins (162) are joined by a brazing method.

[0136] The fourth heat exchange tubes (171) are arranged side by side at intervals, and the fourth heat exchange fins (172) are arranged at intervals in the front-rear direction. Several fourth through holes (172a) through which the fourth heat exchange tubes (171) pass are formed at intervals in the fourth heat exchange fins (172). With the fourth heat exchange fins (172) inserted into the fourth heat exchange tubes (171), the fourth heat exchange tubes (171) and the fourth heat exchange fins (172) are joined by a brazing method.

[0137] The combustion gas passing through the composite heat exchanger (150) moves downward through the gap between the third heat exchanger (161) and the third heat exchanger (161), and between the third heat exchanger fins (162) and the third heat exchanger (162), and heats the fluid to be heated through heat exchange with the fluid flowing inside the third heat exchanger (161).

[0138] Additionally, the combustion gas moves downward through the gap between the fourth heat exchange tube (171) and the fourth heat exchange tube (171), and between the fourth heat exchange fin (172) and the fourth heat exchange fin (172), and heats the fluid to be heated through heat exchange with the fluid flowing inside the fourth heat exchange tube (171).

[0139] In the third and fourth heat exchange fins (162) (172), third and fourth heat exchange grooves (162b) (172b) are formed open upward between the third and fourth through holes (163) (173). However, the depth of the third and fourth heat exchange grooves (162b) (172b) is formed relatively lower than the depth of the first and second heat exchange grooves (142b) (152b). In the latent heat section (130), the temperature of the combustion gas is less than 100°C, so there is no concern about boiling noise, and thus the depth of the third and fourth heat exchange grooves (162b) (172b) is formed low.

[0140] The number of third heat exchange tubes (161) constituting the first latent heat exchange section (160) is configured to be greater than the number of fourth heat exchange tubes (171) constituting the second latent heat exchange section (170). The third heat exchange tubes (161) and the fourth heat exchange tubes (171) are arranged with their centers offset from each other. That is, all three third heat exchange tubes (161) placed at the top and the two fourth heat exchange tubes (171) placed at the bottom are arranged side by side from left to right, but the centers of the nth ones located relative to the third and fourth heat exchange tubes (161) (171) at the left end are not located on the same vertical line but are offset. The center of the upper third heat exchange tube (41) can be located on the vertical line with the center of the space between the fourth heat exchange tubes (171) constituting the bottom.

[0141] Just as the third heat exchange tube (161) of the first latent heat exchanger (160) and the fourth heat exchange tube (171) of the second latent heat exchanger (170) are arranged out of alignment with each other, the second heat exchange tube (151) of the composite heat exchanger (150) and the third heat exchange tube (161) of the first latent heat exchanger (160) are also arranged out of alignment with each other.

[0142] Due to this configuration, in the latent heat exchange section (160)(170), combustion gas transported from the top is transported toward the third and fourth heat exchange tubes (161)(171) and then branches out to both sides of the third and fourth heat exchange tubes (161)(171) and passes through the latent heat exchange section (160)(170) in a manner that surrounds the third and fourth heat exchange tubes (161)(171). Therefore, since the amount of contact between the combustion gas and the third and fourth heat exchange tubes (161)(171) increases, the heat exchange efficiency can be improved.

[0143] In the latent heat section (130), the number of heat exchange tubes (151), (161), and (171) provided in each section decreases as one moves from the top to the bottom. That is, the number of third heat exchange tubes (161) constituting the first latent heat exchange section (160) is reduced compared to the number of second heat exchange tubes (151) constituting the composite heat exchange section (150), and the number of fourth heat exchange tubes (171) constituting the second latent heat exchange section (170) is reduced compared to the number of third heat exchange tubes (161) constituting the first latent heat exchange section (160).

[0144] As described above, when combustion gas flows from the top to the bottom inside the heat exchanger housing (110), the temperature of the combustion gas decreases as it moves downward. Therefore, if the number of heat exchange tubes is maintained at the same level as it moves downward, the amount of heat transferred to each heat exchange tube decreases, and thus the heat exchange efficiency drops. Thus, by reducing the number of heat exchange tubes as it moves downward, the amount of heat transferred to each heat exchange tube can be relatively increased. It is desirable to reduce the cross-sectional area of ​​the combustion gas transport path at the same time as reducing the number of heat exchange tubes.

[0145] The point at which the cross-sectional area of ​​the heat exchanger housing (10) decreases is preferably the point at which condensate is generated, that is, the starting point of the latent heat section (the top of the latent heat section). This is because when the cross-sectional area of ​​the heat exchanger housing (10) decreases, the speed of combustion gas movement increases and the condensate can be discharged more easily. The change in the cross-sectional area of ​​the heat exchanger housing (10) can be achieved by changing the width between the two sides.

[0146] The side of the heat exchanger housing (10) is formed as an inclined surface from the part where the latent heat section (130) begins to the part where the fourth heat exchange fin (172) contacts (the top of the second latent heat exchange section), and the lower part of the inclined surface is formed as a vertical surface. The inclined surface is composed of a first inclined surface (115), a second inclined surface (116), and a third inclined surface (117). The first, second, and third inclined surfaces (115), (116), and (117) may be formed with different slopes.

[0147] The first inclined surface (115) is formed from the height where the latent heat section (130) of the composite heat exchanger (150) begins to the height of the bottom of the second heat exchange fin (152) (the bottom of the composite heat exchanger). The second inclined surface (116) is formed from the height of the bottom of the second heat exchange fin (152) to the height of the bottom of the third heat exchange tube (161). The third inclined surface (117) is formed from the height of the bottom of the third heat exchange tube (161) to the height of the top of the contact section where the heat exchanger housing (110) and the fourth heat exchange fin (172) contact (the top of the second latent heat exchanger).

[0148] The angle formed by the virtual vertical line and the first inclined plane (115) is denoted as θ1, the angle formed by the virtual vertical line and the second inclined plane (116) is denoted as θ2, and the angle formed by the virtual vertical line and the third inclined plane (117) is denoted as θ3. At this time, θ1 > θ2 and θ3 > θ2. That is, the combustion gas passing through the second heat exchange tube (151) and the combustion gas passing through the third heat exchange tube (161) need to be transported downwards quickly, and the cross-sectional area is reduced rapidly compared to other parts. Since the combustion gas that has completely passed through the second heat exchange fin (152) of the composite heat exchanger (150) must make sufficient contact with the third heat exchange tube (161), it is desirable to reduce the cross-sectional area gradually and adjust the transport speed to be relatively slow.

[0149] The second and third inclined surfaces (116) (117) are formed to surround the third heat exchanger (161) located at the edge of the third heat exchanger (161), thereby guiding the combustion gas flowing along the inner edge of the heat exchanger housing (110) to be concentrated toward the third heat exchanger (161). As the second inclined surface (116) moves downward, the third heat exchanger (161) becomes closer. By concentrating the combustion gas being transported downward toward the third heat exchanger (161), the heat exchange efficiency in the third heat exchanger (161) can be increased.

[0150] When the top of the first inclined surface (115) and the bottom of the third inclined surface (117) are connected by an imaginary diagonal line, the connection between the second inclined surface (116) and the third inclined surface (117) protrudes outward from the diagonal line, and the connection between the second inclined surface (116) and the third inclined surface (117) is located next to the first latent heat exchanger (160). This structure prevents the connection between the second and third inclined surfaces (116) (117) from coming into contact with or coming too close to the third heat exchanger (161) located at the edge of the first latent heat exchanger (160), thereby allowing the flow of exhaust air to be smooth between the second and third inclined surfaces (116) (117) and the third heat exchanger (161) located at the edge.

[0151] The inclined surfaces (115), (116), and (117) formed on both sides of the heat exchanger housing (110) serve as side guide means to concentrate the flow of combustion gas into the heat exchange tubes. Additionally, the inclined surfaces (115), (116), and (117) allow for smooth discharge of condensate in the latent heat section (130).

[0152] Meanwhile, the ends of the first, second, third, and fourth heat exchange fins (142)(152)(162)(172), that is, the parts in contact with the heat exchanger housing (110), are formed to be identical in shape to the parts in contact with the inner surface of the heat exchanger housing (110).

[0153] Side guide means are provided on both sides of the third heat exchange fin (162) to guide the flow of combustion gas, which is being transferred to both sides of the third heat exchange fin (162) among the combustion gas moving to the first latent heat exchange section (160), toward the third heat exchange tube (161).

[0154] The side guide means is formed in the shape of an inclined plate positioned between two third through holes (162a) located at both edges of three third through holes (162a) and both ends of the third heat exchange pin (162), that is, between the side of the heat exchanger housing (110) and the third heat exchange tube (16) adjacent thereto, and is configured to include a first side guide (162c) and a second side guide (162d).

[0155] The first side guide (162c) is a plate that is bent backward and protrudes from the upper edges of both sides of the third heat exchange fin (162), that is, between the third through hole (162a) and both ends, thereby shielding the flow of combustion gas. The first side guide (162c) is formed to be inclined downward from both ends toward the third through hole (162a), so that the flow of combustion gas striking the first side guide (162c) is guided to concentrate on the third heat exchange tube (161). The first side guide (162c) contacts the inner surface of the heat exchanger housing (110).

[0156] The second side guides (162d) are formed vertically spaced apart from the lower side guide (162c) and are inclined in the same shape as the first side guide (162c). That is, they are formed to be inclined downward toward the third through hole (162a). The second side guides (162d) are formed protrudingly by cutting a part of the third heat exchange fin (162) and bending it backward. The second side guides (162d) guide the flow of combustion gas passing between the heat exchanger housing (110) and the adjacent third heat exchange tube (161) so that it is concentrated toward the adjacent third heat exchange tube (161), thereby improving the contact time between the combustion gas and the third heat exchange tube (161) and improving heat exchange performance.

[0157] Due to the inclined surfaces of the first side guide (162c) and the second side guide (162d), the discharge of condensate can also be easily guided.

[0158] In the third heat exchange fin (162), between the two third through holes (162a) arranged side by side on the left and right sides, second central guides (162e) are arranged vertically spaced apart as central guide means to slow down the passage speed of the combustion gas and guide the flow of the combustion gas to concentrate toward the third heat exchange tubes (161). The second central guides (162e) are formed in the shape of horizontal plates that protrude by being bent backward after a part of the third heat exchange fin (162) is cut.

[0159] Between the two fourth through holes (172a) arranged side by side on the fourth heat exchange fin (172), third central guides (172c) are arranged vertically spaced apart to serve as central guide means for slowing down the passage speed of combustion gas and guiding the flow of combustion gas toward the fourth heat exchange tubes (171). The third central guides (172c) are formed in the shape of horizontal plates that protrude by being bent backward after a part of the fourth heat exchange fin (172) is cut.

[0160] The second and third central guides (162e) (172c) are arranged in a vertical configuration, but are not limited to this configuration; it is also possible to arrange only one, or to arrange three or more.

[0161] Between the two third through holes (162a) arranged side by side on the left and right sides of the third heat exchange fin (162), a fourth central guide (162f) is formed below the second central guides (162e) as a central guide means to guide the flow of combustion gas to concentrate on the third heat exchange tubes (161). The fourth central guide (162f) is formed in a circular shape when viewed from the rear and is formed to protrude in a cylindrical shape by bending backward from the third heat exchange fin (162). The fourth central guides (162f) are positioned below the center of the third heat exchange tube (161).

[0162] Between the fourth heat exchange fin (172) and the fourth through hole (172a), a fifth central guide (172d) is formed as a central guide means to guide the flow of combustion gas to concentrate on the fourth heat exchange tubes (171) below the third central guides (172c). The fifth central guide (172d) is formed in a circular shape when viewed from the rear and is formed to protrude in a cylindrical shape by bending backward from the fourth heat exchange fin (172). The fifth central guides (172d) are positioned below the center of the fourth heat exchange tube (171).

[0163] The combustion gas hitting the second and third central guides (162e) (172c) descends through the third and fourth heat exchange tubes (161) (171) and the second and third central guides (162e) (172c) with reduced speed, and descends through the fourth and fifth central guides (162f) (172d) and the third and fourth heat exchange tubes (161) (171). Through this flow structure, the combustion gas flows concentratedly into the third and fourth heat exchange tubes (161) (171) in a form that surrounds the third and fourth heat exchange tubes (161) (171).

[0164] Around the perimeter of the third and fourth through holes (162a) (172a), bending contact portions (162g) (172e) are formed, which are bent backward to contact the outer surface of the third and fourth heat exchange tubes (161) (171). Additionally, bending contact portions (162h) (172f) are formed at both ends of the third and fourth heat exchange fins (162) (172), which are bent backward to contact the inner surface of the heat exchanger housing (110).

[0165] Meanwhile, condensate discharge grooves (152g) (162i) (172g) in the shape of a groove open downward can be formed at the bottom of the third and fourth heat exchange fins (152) (162) (172). Condensate flowing down along the front or back of each heat exchange fin (152) (162) (172) is collected in the condensate discharge grooves (152g) (162i) (172g) at the bottom and then falls. That is, since the flowing condensate is collected in the condensate discharge grooves (152g) (162i) (172g), the amount of condensate increases, allowing the condensate to be easily separated and fall from the heat exchange fins (152) (162) (172). If the condensate discharge grooves (152g)(162i)(172g) are not formed, the condensate is dispersed and accumulates at the bottom of the heat exchange fins (152)(162)(172), so the load is small, making it difficult to fall easily and causing the accumulation time to be prolonged.

[0166]

[0167] FIG. 17 is a cross-sectional view showing combustion gas being discharged through the exhaust passage and condensate being discharged through the condensate outlet.

[0168] The exhaust passage (500) provides a passage for discharging combustion gas passing through the heat exchanger (100) to the outside, and is formed by including a condensate receiver (510) and a side pipe (520). The flow of combustion gas in the exhaust passage (500) must be smooth so that the flow of combustion gas in the previous stage of the heat exchange process can be smooth and the heat exchange performance can be improved.

[0169] The condensate receiving tank (510) is connected to the open bottom of the heat exchanger (100) and receives not only the combustion gas discharged from the heat exchanger (100) but also the condensate generated in the heat exchanger (100) and flowing down.

[0170] At the upper part of the condensate receiver (510), a heat exchanger connection part (511) connected to the open bottom of the heat exchanger (100) and a side pipe connection part (512) connected to the bottom of the side pipe (520) are formed spaced apart. A condensate discharge port (513) is formed at the lower part of the condensate receiver (510), and the inner bottom surface of the condensate receiver (510) is formed at an angle so that condensate discharged from the heat exchanger (100) can easily collect at the condensate discharge port (513).

[0171] A support member (514) that maintains the gap between the upper surface and the lower surface of the condensate receiver (510) may be provided between the heat exchanger connection part (511) and the side pipe connection part (512) inside the condensate receiver (510). The support member (514) is inserted between the upper surface and the lower surface of the condensate receiver (510) and can be fixed to the lower surface of the condensate receiver (510) using a bolt member. Since the gap between the upper surface and the lower surface of the condensate receiver (510) is maintained at a constant level by the support member (514), the internal space of the condensate receiver (510) can be maintained without deformation, thereby allowing the flow of combustion gas to be smooth.

[0172] The side pipe (520) is connected to the side pipe connection (512) of the condensate receiver (510) and is installed on the side of the heat exchanger (100) to form an exhaust path for combustion gas. The side pipe (520) can be molded from plastic material.

[0173] The side pipe (520) includes a first vertical section (521) vertically connected to the side pipe connection (512) of the condensate receiver (510), an inclined section (522) inclined outward from the top of the first vertical section (521), and a second vertical section (523) vertically connected from the top of the inclined section (522).

[0174] The first vertical section (521) and the inclined section (522) are located next to the heat exchanger (100), and the second vertical section (523) is located next to the combustion chamber (700). Since the temperature inside the combustion chamber (700) is relatively higher than the temperature inside the heat exchanger (100), the gap between the second vertical section (523) and the combustion chamber (700) can be formed wider than the gap between the first vertical section (521) and the inclined section (522) and the heat exchanger (100).

[0175] The first vertical section (521) is positioned to correspond to the height of the first and second latent heat exchange sections (160) (170), the inclined section (522) is positioned to correspond to the height of the sensible heat exchange section (140) and the combined heat exchange section (150), and the second vertical section (523) can be positioned next to the combustion chamber (700).

[0176]

[0177] FIG. 18 is an enlarged view showing the arrangement relationship between the side piping and the heat exchanger housing shown in FIG. 17.

[0178] Let's examine the change in the gap between the side pipe (520) and the heat exchanger housing (110).

[0179] The first vertical section (521) of the side pipe (520) is installed vertically next to the second and third inclined surfaces (116) (117) of the heat exchanger housing (110) and the vertical surface (118) formed below the third inclined surface (117).

[0180] The gap between the first vertical section (521) and the vertical surface (118) is kept constant, and the gap between the first vertical section (521) and the second and third inclined surfaces (116) (117) gradually narrows as it goes upward.

[0181] The inclined portion (522) of the side pipe (520) is inclined toward the outside of the boiler, the reason being to position the second vertical portion (523), which is placed next to the combustion chamber (700) as described above, far away from the combustion chamber (700). Since the side pipe (520) is made of plastic, the distance between the second vertical portion (523) and the combustion chamber (700) must be far so that deformation of the second vertical portion (523) does not occur due to the heat emitted from the combustion chamber (700).

[0182] The lower side portion of the side of the inclined section (522) facing the heat exchanger housing (110) is located closest to the heat exchanger housing (110) within the entire section of the side piping (520) and forms an inclined surface facing the first inclined surface (115) of the heat exchanger housing (110).

[0183] Among the sides of the first vertical section (521), the inclined section (522), and the second vertical section (523), the side facing the heat exchanger housing (110) or the combustion chamber (700) and the side opposite to it may be formed with different upper and lower lengths. For example, in the case of the first vertical section (521), the length of the opposite side may be formed longer than the side facing the heat exchanger housing (110); in the case of the inclined section (522), the length of the side facing the heat exchanger housing (110) may be formed longer than the opposite side; and in the case of the second vertical section (523), the length of the opposite side may be formed longer than the side facing the combustion chamber (700).

[0184] As described above, the heat exchanger housing (110) is formed such that the cross-sectional area of ​​the section corresponding to the latent heat section (130) gradually decreases. That is, from the part where the sensible heat section (120) changes to the latent heat section (130) up to the second latent heat exchanger (170), a decreasing section is formed in which the cross-sectional area gradually decreases from the top to the bottom, and from the second latent heat exchanger (170) to the bottom of the latent heat section (130), a maintaining section is formed in which the cross-sectional area is maintained at a constant level.

[0185] The side of the boiler case is formed vertically, and the side pipe (520) constituting the exhaust passage (500) is positioned between the side of the boiler case and one side of the heat exchanger housing (110). Accordingly, the volume of the side pipe (520) can be determined according to the gap between the side of the boiler case and one side of the heat exchanger housing (110).

[0186] As the volume of the side pipe (520) increases, the discharge of combustion gas can be carried out more smoothly. Accordingly, in a preferred embodiment of the present invention, structures as described above are applied to increase the volume of the side pipe (520) and improve the heat exchange efficiency within the heat exchanger housing (110).

[0187] That is, in the case of the heat exchanger housing (110), in the contraction section, the sides are formed as inclined surfaces so that they become closer to each other as they go from the top to the bottom, and the inclined surfaces are formed separately as first, second, and third inclined surfaces (115)(116)(117). In the contraction section, due to the inclined surfaces of the heat exchanger housing (110), the space where the side pipe (520) can be located gradually expands as it goes downward. The width between the upper sides of the heat exchanger housing (110) that surrounds the sensible heat section (120) is maintained constant, and the width between the lower sides that surround the latent heat section (130) is formed to be narrower than the width between the upper sides. Through this, a space is formed between the imaginary vertical line passing through the upper sides and the lower sides, and the volume of the side pipe (520) can be expanded into this space.

[0188] Additionally, in the case of the side piping (520), a first vertical section (521) is configured as a volume expansion section in which the volume extends to the space formed on both lower sides of the heat exchanger housing (110), and an inclined section (522) and a second vertical section (523) are sequentially formed above it. The first vertical section (521) can extend to the space below the first inclined surface (115).

[0189] Meanwhile, on the side of the side pipe (520) facing the heat exchanger housing (110) and the combustion chamber (700), a spacing rib (524) is formed to prevent the side pipe (520) from coming into contact with the heat exchanger housing (110) and the combustion chamber (700). As described above, since the side pipe (520) is made of plastic material, thermal deformation can be prevented if it comes into contact with the heat exchanger housing (110) and the combustion chamber (700). Therefore, thermal deformation can be prevented by maintaining a gap between the side pipe (520) and the heat exchanger housing (110) and the combustion chamber (700) through the spacing rib (524).

[0190]

[0191] An integrated heat exchanger according to a second embodiment of the present invention will be described through FIGS. 19 to 25.

[0192] FIG. 19 is a cross-sectional view showing the interior of an integrated heat exchanger according to a second embodiment of the present invention.

[0193] According to the integrated heat exchanger according to the second embodiment of the present invention, a sensible heat section (1200) where sensible heat exchange takes place and a latent heat section (1300) where latent heat exchange takes place are formed vertically within the internal space of the heat exchanger housing (1100). Multistage heat exchange sections (1400)(1500)(1600)(1700) are arranged vertically within the internal space of the heat exchanger housing (1100).

[0194] The heat exchanger housing (1100) forms a combustion gas transport path through which combustion gas moves within the internal space, forms an intake section (1110) connected to the combustion chamber (700) at the top, and forms an exhaust section (1120) connected to the exhaust passage at the bottom. Through the combustion gas transport path, the combustion gas moves from the top to the bottom.

[0195] According to the second embodiment of the present invention configured as such, the integrated heat exchanger is identical to the integrated heat exchanger (100) according to the first embodiment of the present invention, except for a part of the sensible heat exchanger (1400) and the composite heat exchanger (1500), so the description thereof is omitted.

[0196]

[0197] FIG. 20 is a drawing showing the combustion gas flow in the sensible heat section, FIG. 21 is a cross-sectional view showing the internal structure of the first heat exchange tube, FIG. 22 is a front view of the first heat exchange fin, and FIG. 23 is a perspective view of the first heat exchange fin viewed from the rear.

[0198] The sensible heat exchanger (1400) includes a plurality of first heat exchange tubes (1410) and a plurality of first heat exchange fins (1420) surrounding the first heat exchange tubes (1410). The first heat exchange fins (1420) are each provided with a first through hole (1421) and a first heat exchange groove (1422) corresponding to the first through hole (142a) and the first heat exchange groove (142b) that constitute the first heat exchange fin (142) described in the first embodiment of the present invention. Since the shape and function of the first through hole (1421) and the first heat exchange groove (1422) are the same as in the first embodiment, their description will be omitted.

[0199] A first central guide means (1423) is formed in the first heat exchange fin (1420) to guide the flow of exhaust air passing between the first heat exchange tubes (1410) to be concentrated on both first heat exchange tubes (1410). The first central guide means (1423) includes a first central guide (1423a) and a bending portion (1423b).

[0200] The first central guide (1423a) is positioned below the center of the first heat exchange tube (1410) between the first heat exchange tubes (1410) and is formed to slope downward toward each of the two first heat exchange tubes (1410), and is composed of a left guide (1423c) and a right guide (1423d) that are symmetrical and spaced apart from each other. The first central guide (1423a) is formed by bending.

[0201] The bending portion (1423b) is formed by bending at the bottom of the first heat exchange fin (1420) and is positioned below the left guide (1423c) and the right guide (1423d).

[0202] Some of the combustion gas descending between the first heat exchange tubes (1410) moves along the outer slopes of the left guide (1423c) and the right guide (1423d) and is guided to the lower part of the left first heat exchange tube (1410) and the lower part of the right first heat exchange tube (1410), respectively, while the remainder descends through the space between the left guide (1423c) and the right guide (1423d) and is guided to the lower part of the left first heat exchange tube (1410) and the lower part of the right first heat exchange tube (1410), respectively, by the bending section (1423b). In this way, the entire amount of combustion gas passing between the first heat exchange tubes (1410) is guided to the lower part of the first heat exchange tubes (1410) by the first central guide (1423a) and the bending section (1423b), thereby improving the fluid heating efficiency in the first heat exchange tubes (1410).

[0203] As described above, the flow of combustion gas passing between the first heat exchange tubes (1410) is divided into a first path flowing along the outer slopes of the left and right guides (1423c) (1423d) constituting the first central guide (1423a) and a second path flowing along the space between the left and right guides (1423c) (1423d), and is guided toward the lower side of the first heat exchange tubes (1410), thereby minimizing resistance when the combustion gas flows from top to bottom, so that the flow of combustion gas can be smooth.

[0204] The combustion gas is dispersed to both sides of the bending section (1423b) and then descends through the bending section (1423b) toward the composite heat exchanger (1500) below.

[0205] Side guides (1424) are formed on both edges of the first heat exchange fin (1420) to guide the flow of combustion gas passing between the first heat exchange tubes (1410) located at both edges of the first heat exchange fin (1420) and the inner surface of the heat exchanger housing (1100) toward the first heat exchange tubes (1410). The side guides (1424) are formed to slope downward from the inner surface of the heat exchanger housing (1100) toward the first heat exchange tubes (1410). The side guides (1424) are formed by bending.

[0206] The interior of the first heat exchanger (1410) is separated into upper and lower spaces by a partition (1411), and communication holes (not shown) that connect the upper and lower spaces are spaced apart and formed in the partition (1411). Turbulators (1412) inclined toward the lower space relative to the partition (1411) may be formed at the edges of the communication holes. Two turbulators (1412) are formed left and right in one communication hole. One turbulator (1412) is formed inclined toward the direction in which the fluid to be heated flows, and the other turbulator (1412) is formed inclined toward the direction in which the fluid to be heated flows, so that the fluid flowing in the upper space of the partition (1411) and the fluid flowing in the lower space can be mixed evenly.

[0207] Since the turbulators (1412) are formed only in the lower space relative to the partition (1411), the fluid flow is rapid in the upper space of the partition (1411), and the fluid flow is relatively slow in the lower space. Through the turbulence generating structure composed of the partition (1411), the connecting hole, and the turbulators (1412), the fluid to be heated flowing inside the first heat exchanger (1410) can be heated uniformly. In particular, since the temperature of the combustion gas passing through the sensible heat exchanger (1400) is high, the heat exchange efficiency can be further increased by evenly mixing the fluid to be heated flowing inside the first heat exchanger (1410) as described above.

[0208] Combustion gas flowing into the upper side of the sensible heat exchanger (1400) can be rapidly transferred to the lower side of the first heat exchange tubes (1410) by means of a first heat exchange groove (1422) open to the upper side between the first through holes (1421) in the first heat exchange fin (1420) and a first central guide means (1423) formed between the first heat exchange tubes (1410), and fluid flow can be rapidly achieved in the upper space located towards the combustion chamber inside the first heat exchange tube (1410). Through this structure, the phenomenon of boiling that may occur in the upper side of the sensible heat exchanger (1400) can be minimized, and the generation of boiling noise and scale formation can also be effectively reduced.

[0209]

[0210] FIG. 24 is a front view of the second heat exchange fin, and FIG. 25 is a perspective view of the second heat exchange fin viewed from the rear.

[0211] The composite heat exchanger (1500) includes a plurality of second heat exchange tubes (1510) and a plurality of second heat exchange fins (1520) surrounding the second heat exchange tubes (1510). The second heat exchange fins (1520) are each provided with a second through hole (1521) and a first heat exchange groove (1522) corresponding to the second through hole (152a) and the first heat exchange groove (152b) that constitute the second heat exchange fin (152) described in the first embodiment of the present invention. Since the shape and function of the first through hole (1521) and the first heat exchange groove (1522) are the same as in the first embodiment, their description will be omitted.

[0212] A second central guide means (1523) is formed between the second heat exchange fin (1520) and the second through hole (1521), that is, in the center between the two second heat exchange tubes (1510) arranged side by side on the left and right, to guide the flow of combustion gas to concentrate on the second heat exchange tubes (1510). The second central guide means (1523) includes a second central guide (1523a) and an exhaust resistance guide (1523b).

[0213] The second central guide (1523a) is formed in an '∧' shape and is located below the second heat exchange groove (1522). The exhaust resistance guide (1523b) is provided below the passage formed between the second heat exchange tube (1510) and the second central guide (1523a) to provide resistance to slow down the flow of exhaust passing through the passage, and is formed to slope downward from the second heat exchange tube (1510) toward the bottom of the second central guide (1523a). The second central guide (1523a) and the exhaust resistance guide (1523b) are formed by bending.

[0214] Since the combined heat exchanger (1500) heats the fluid to be heated at a temperature higher than that of the sensible heat exchanger (1400), it is desirable for the combined heat exchanger (1500) to have a structure capable of trapping heat, that is, a structure capable of stagnating the flow of combustion gas, just as in the sensible heat exchanger (1400). However, since the lower temperature of the combined heat exchanger (1500) is about 70°C, the structure that traps heat may be configured to hinder the discharge of condensate. Therefore, in the present invention, the combustion gas flowing between the second heat exchanger tubes (1510) is concentrated as much as possible in the second heat exchanger tubes (1510) through the second central guide (1523a).

[0215] Specifically, the second central guide (1523a) is located below the center of the two second heat exchange tubes (1510) and is formed to slope downward diagonally toward the left and right second heat exchange tubes (1510) as it goes from the center to both ends, so that the distance between the ends widens as it goes toward the ends. The height at which the second central guide (1523a) is formed is located between the center and the bottom of the second heat exchange tubes (1510). The ends of the second central guide (1523a) are each formed as left-right symmetrical inclined surfaces and guide the flow so that the combustion gas passing between the second heat exchange tubes (1510) flows while concentrating on the second heat exchange tubes (1510). Through this, the time that the combustion gas is in contact with the second heat exchange tubes (1510) is extended, so the fluid to be heated flowing through the second heat exchange tubes (1510) can be effectively heated.

[0216] In addition, because the space between the second heat exchange tube (1510) and the second central guide (1523a) is narrow, the combustion gas moves at a high speed, allowing the condensate formed on the lower part of the second heat exchange fin (1520) to be easily dropped and discharged. Meanwhile, the ends of both ends of the second central guide (1523a) may be the point at which condensate is generated, that is, the point at which the latent heat section begins. If the ends of both ends of the second central guide (1523a) are above the point at which condensate is generated, the combustion gas cannot concentrate and flow to the lower part of the second heat exchange tube (1510), and conversely, if the ends of the second central guide (1523a) are below the point at which condensate is generated, it is difficult to send the condensate to the combustion gas, which may cause problems with condensate discharge.

[0217] As described above, the cross-sectional area of ​​the combustion gas transport path where the latent heat section (1300) is located is formed to be narrower than the cross-sectional area of ​​the combustion gas transport path where the sensible heat section (1200) is located. That is, since the width of the heat exchanger housing (1100) narrows as it goes downward in the latent heat section (1300), the velocity of the combustion gas also increases. The point at which the width begins to narrow can be the point at which condensate is generated, that is, the point at which the latent heat section (1300) begins. The lower part of the second heat exchange fin (1520) is located at the part where the latent heat section (1300) begins, and both sides of the second heat exchange fin (1520) are also formed in a shape where the width narrows as it goes downward. Accordingly, if the point where the latent heat section (1300) begins is virtually indicated by a horizontal line, the point where the width of the heat exchanger housing (1100) narrows, the point where the width of the second heat exchange fin (1520) narrows, and the ends of both sides of the second central guide (1523a) can be positioned side by side on the virtual horizontal line.

[0218] The exhaust resistance guide (1523b) is configured to cause the combustion gas passing between the second heat exchanger (1510) and the second central guide (1523a) to collide, thereby slowing down the flow of combustion gas between the second heat exchanger (1510) and the second central guide (1523a) so that sufficient heat can be transferred to the second heat exchanger (1510). Additionally, the exhaust resistance guide (1523b) is located in the latent heat section (1300) and can form a discharge path for condensate.

[0219] A circular hole (1524) is formed below the second central guide (1523a) in the second heat exchange fin (1520). This circular hole (1524) reduces the area located below the second central guide (1523a) in the second heat exchange fin (1520), that is, the area located in the latent heat section (1300), thereby reducing the area where condensation forms. Therefore, even if condensation forms on the lower part of the second heat exchange fin (1520), the contact area between the condensation and the second heat exchange fin (1520) is reduced, making it easier to discharge the condensation.

[0220]

[0221] An integrated heat exchanger according to a third embodiment of the present invention will be described through FIGS. 26 to 34.

[0222] FIG. 26 is a cross-sectional view showing the interior of an integrated heat exchanger according to a third embodiment of the present invention.

[0223] According to the integrated heat exchanger (2100) of the third embodiment of the present invention, a sensible heat section (2120) where sensible heat exchange takes place and a latent heat section (2130) where latent heat exchange takes place are formed vertically within the internal space of the heat exchanger housing (2110). Multistage heat exchange sections (2140) (2150) (2160) (2170) are arranged vertically within the internal space of the heat exchanger housing (2110).

[0224] According to the heat exchanger (2100) according to the third embodiment of the present invention configured as such, the first latent heat exchanger (2160) is identical to the first latent heat exchanger (160) of the integrated heat exchanger (100) according to the first embodiment of the present invention, so the description thereof will be omitted.

[0225]

[0226] FIG. 27 is a diagram showing the combustion gas flow in the sensible heat section, FIG. 28 is a cross-sectional view showing the internal structure of the first heat exchange tube, FIG. 29 is a front view of the first heat exchange fin, and FIG. 30 is a perspective view of the first heat exchange fin viewed from the rear.

[0227] The sensible heat exchanger (2140) includes a plurality of first heat exchange tubes (2141) and a plurality of first heat exchange fins (2142) surrounding the first heat exchange tubes (2141).

[0228] The interior of the first heat exchange tube (2141) is separated into upper and lower spaces by a partition (2141a), and communication holes (2141b) that connect the upper and lower spaces are spaced apart and formed in the partition (2141a), and inclined surfaces (2141c) that are inclined upward and downward relative to the partition (2141a) may be alternately formed around the communication holes (2141b). The inclined surfaces (2141c) are formed to be inclined in the direction in which the fluid to be heated flows, so that the fluid to be heated flowing along the upper space of the partition (2141a) may mix with the lower space, and the fluid to be heated flowing along the lower space may mix with the upper space. Through this turbulence generation structure, the fluid to be heated flowing inside the first heat exchange tube (2141) can be heated uniformly, and boiling noise can be reduced together with the first heat exchange groove (2142b) to be described later. In particular, since the temperature of the combustion gas passing through the sensible heat exchanger (2140) is high, the heat exchange efficiency can be further increased by evenly mixing the fluid to be heated flowing through the first heat exchanger (2141) as described above.

[0229] The first heat exchange fins (2142) may each be provided with a first through hole (2142a) and a first heat exchange groove (2142b) corresponding to the second through hole (152a) and the first heat exchange groove (142b) constituting the first heat exchange fin (142) described in the first embodiment of the present invention. Since the shape and function of the first through hole (2142a) and the first heat exchange groove (2142b) are the same as in the first embodiment, their description will be omitted.

[0230] A bending portion (2142c) is formed in the first heat exchange fin (2142) as a central guide means to guide the flow of exhaust air passing between the first heat exchange tubes (2141) to be concentrated on both first heat exchange tubes (2141). Since the shape and position of the bending portion (2142c) are the same as the bending portion (142c) of the first embodiment, the description thereof will be omitted.

[0231] Combustion gas descending between the first heat exchange tubes (2141) can be guided to the lower part of the left first heat exchange tube (2141) and the lower part of the right first heat exchange tube (2141), respectively, by the bending section (2142c). In this way, the entire amount of combustion gas passing between the first heat exchange tubes (2141) is guided to the lower part of the first heat exchange tubes (2141) by the bending section (2142c), thereby improving the fluid heating efficiency in the first heat exchange tubes (2141).

[0232]

[0233] FIG. 31 is a front view of the second heat exchange fin, and FIG. 32 is a perspective view of the second heat exchange fin viewed from the rear.

[0234] The composite heat exchanger (2150) includes a plurality of second heat exchange tubes (2151) and a plurality of second heat exchange fins (2152) surrounding the second heat exchange tubes (2151). In the drawing, four second heat exchange tubes (2151) are arranged side by side with spacing, and the second heat exchange fins (2152) are arranged with spacing in the front-rear direction. A plurality of second through holes (2152a) through which the second heat exchange tubes (2151) pass are formed spaced apart from side to side in the second heat exchange fins (2152), and the second heat exchange tubes (2151) and the second heat exchange fins (2152) can be joined by a brazing method while the second heat exchange tubes (2151) are fitted with the second heat exchange fins (2152).

[0235] The composite heat exchanger (2150) having such a configuration differs from the composite heat exchanger (150) of the first embodiment only in the shape of the second heat exchange fin (2152), and since other technical features are identical, the description thereof will be omitted.

[0236] In the case of the second heat exchange fins (2152) constituting the composite heat exchanger (2150), second heat exchange grooves (2152b) having the same function as the first heat exchange groove (2142b) formed in the first heat exchange fins (2142) may also be formed. Additionally, the depth of the second heat exchange groove (2152b) may be formed to be the same as the depth of the first heat exchange groove (2142b).

[0237] A central guide (2152c) is formed in the lower portion between two second through holes (2152a) arranged side by side on the left and right sides of the second heat exchange fin (2152) as a central guide means to guide the flow of combustion gas passing between the second through holes (2152a) to be concentrated at the lower portion of the second heat exchange tubes (2151). The central guide (2152c) is formed in a circular shape when viewed from the rear and is formed to protrude in a cylindrical shape by bending backward from the second heat exchange fin (2152). The central guides (2152c) may be positioned below the center of the second heat exchange tubes (2151).

[0238] Condensate discharge grooves (2152d) in the shape of a downwardly open groove may be formed at the bottom of the second heat exchange fin (2152). Condensate flowing down along the front or back of each heat exchange fin (2152) is collected in the bottom condensate discharge groove (2152d) and then falls.

[0239]

[0240] FIG. 33 is a diagram showing the flow of combustion gas in the latent heat section, and FIG. 34 is an enlarged view of the second latent heat exchanger of FIG. 33.

[0241] As shown in FIG. 33, the cross-sectional area of ​​the space inside the heat exchanger housing (2110), that is, the combustion gas transport path, gradually decreases between the composite heat exchanger (2140) and the second latent heat exchanger (2170). As the cross-sectional area of ​​the combustion gas transport path decreases along the direction of combustion gas flow, the flow of combustion gas can be guided toward the center and the flow velocity can be increased, making it easier to discharge condensate.

[0242] The first latent heat exchanger (2160) may be configured to include a third heat exchange tube (2161) and a third heat exchange fin (2162), and since it is identical to the first latent heat exchanger (160) of the first embodiment, the description will be omitted.

[0243] The second latent heat exchanger (2170) may include a plurality of fourth heat exchange tubes (2171). Since the combustion gas flowing into the second latent heat exchanger (2170) is introduced with a lowered temperature due to heat exchange in the previous stage, the heat exchange fins may be omitted and the unit may be composed only of fourth heat exchange tubes (2171) to improve the heat exchange efficiency with the combustion gas. The fourth heat exchange tubes (2171) may be formed as tubes with a smaller diameter than the first, second, and third heat exchange tubes (2141) (2151) (2161), and a plurality of them may be spaced apart at intervals.

[0244] As described above, the flow of combustion gas being transported toward the second latent heat exchanger (2170) is guided toward the center, and the fourth heat exchanger tubes (2171) can be arranged in an arch shape with the center generally convex toward the first latent heat exchanger (2160) in response to the flow of combustion gas entering the second latent heat exchanger (2170). Additionally, the fourth heat exchanger tubes (2171) can be arranged in two rows, and to maintain the arch shape, the number of fourth heat exchanger tubes (2171) constituting the lower row may be less than the number of fourth heat exchanger tubes (2171) constituting the upper row. Furthermore, the flow path of combustion gas connecting the gap between the fourth heat exchanger tubes (2171) constituting the upper row and the gap between the fourth heat exchanger tubes (2171) constituting the lower row can be formed in an arch shape.

[0245] By arranging the fourth heat exchange tubes (2171) in the above structure, the flow of combustion gas is maintained smoothly without obstruction, so that the flow rate can be maintained and the condensate discharge can be carried out smoothly.

[0246] Meanwhile, unexplained reference numeral 2172 is a heat exchange tube support panel that supports the fourth heat exchange tubes (2171).

[0247]

[0248] As described above, an integrated heat exchanger and a boiler according to a preferred embodiment of the present invention have been described in detail with reference to the attached drawings; however, the present invention is not limited to the embodiments described above and can be implemented with various modifications within the scope of the claims.

[0249] [Explanation of the symbol]

[0250] 100 : Heat exchanger 110 : Heat exchanger housing

[0251] 111: First flange section 112: Deformation prevention rib

[0252] 113: Intake section 114: Exhaust section

[0253] 115: First slope 116: Second slope

[0254] 117: Third inclined plane 118: Vertical plane

[0255] 120: Sensible heat section 130: Latent heat section

[0256] 140: Sensible heat exchanger 141: First heat exchange tube

[0257] 142: First heat exchange fin 150: Composite heat exchanger

[0258] 151: 2nd heat exchange tube 152: 2nd heat exchange fin

[0259] 160: 1st latent heat exchanger 161: 3rd heat exchange tube

[0260] 162: 3rd heat exchange fin 170: 2nd latent heat exchanger

[0261] 171: 4th heat exchange tube 172: 4th heat exchange fin

[0262] 200 : Intake fan 300 : Gas inlet

[0263] 400: Air inlet 500: Exhaust passage

[0264] 510: Condensate collector 511: Heat exchanger connection

[0265] 512: Side pipe connection 513: Condensate drain

[0266] 514: Support member 520: Side piping

[0267] 521: 1st vertical section 522: Inclined section

[0268] 523: 2nd vertical section 524: Separating rib

[0269] 600 : Burner 700 : Combustion chamber

[0270] 710: Combustion chamber housing 711: Second flange section

[0271] 712 : Heat exchange tube insertion groove 800 : Insulation material

[0272] 900 : Insulation fixing means

Claims

A housing having an intake section and an exhaust section for the inflow and outflow of combustion gases, and having a combustion gas transfer path inside connecting the intake section and the exhaust section; and A plurality of heat exchange sections spaced apart in a combustion gas transport path, including a heat exchange tube through which a heated fluid flows; The above heat exchanger comprises a sensible heat exchanger in which sensible heat exchange is performed, and a latent heat exchanger in which latent heat exchange is performed. Integrated heat exchanger. In Article 1, The above heat exchanger is, A composite heat exchanger further comprising sensible heat exchange and latent heat exchange, Integrated heat exchanger. In Article 2, The above sensible heat exchanger, combined heat exchanger, and latent heat exchanger are arranged sequentially along the direction of combustion gas transport. Integrated heat exchanger. In Paragraph 3, The combustion gas transport path includes a cross-sectional area reduction section in which the cross-sectional area decreases as it moves toward the exhaust section, Integrated heat exchanger. In Paragraph 4, The combustion gas transport path further includes at least one cross-sectional area maintaining section in which the cross-sectional area is maintained, Integrated heat exchanger. In Paragraph 4, The cross-sectional area reduction section is a form in which the cross-sectional area decreases as the width between the two sides of the housing narrows, Integrated heat exchanger. In Article 6, The portion constituting the section of reduced cross-sectional area among the two sides of the housing includes at least two inclined surfaces with different slopes, and the inclined surfaces are formed consecutively. Integrated heat exchanger. In Paragraph 3, The combustion gas conveying path is formed so that the combustion gas flows from top to bottom within the housing, and within it, a sensible heat exchanger, a combined heat exchanger, and a latent heat exchanger are arranged spaced apart from top to bottom. Integrated heat exchanger. In Article 8, The combustion gas transport path is, Sensible heat section including the entire sensible heat exchanger and a portion of the combined heat exchanger; and A latent heat section including a part of the composite heat exchanger and the entire latent heat exchanger; including Integrated heat exchanger. In Article 6, The heat exchanger includes first, second, third, and fourth heat exchangers arranged spaced apart in order from top to bottom, and The first, second, and third heat exchange sections have a structure in which a plurality of heat exchange tubes are arranged spaced apart from left to right, and heat exchange fins are fitted spaced apart on the outer sides of the heat exchange tubes. The fourth heat exchanger is composed solely of a plurality of heat exchange tubes spaced apart, Integrated heat exchanger. In Article 10, The diameter of the heat exchange tube constituting the fourth heat exchanger is smaller than the diameter of the heat exchange tube constituting the first, second, and third heat exchangers, Integrated heat exchanger. In Article 10, Sensible heat exchange takes place in the first heat exchange section, and In the second heat exchanger, sensible heat exchange and latent heat exchange take place together, and In the third and fourth heat exchange sections, latent heat exchange takes place, Integrated heat exchanger. In Article 12, The cross-sectional area of ​​the space where the first and second heat exchangers are arranged is maintained constant, the cross-sectional area of ​​the space between the second heat exchanger and the fourth heat exchanger gradually decreases, and the cross-sectional area of ​​the space where the fourth heat exchanger is arranged is maintained constant. Integrated heat exchanger. In Article 13, With respect to a virtual centerline passing vertically through the center of the combustion gas transport path, the sides of the housing are symmetrical. Integrated heat exchanger. In Article 14, A plurality of heat exchange tubes constituting the fourth heat exchange section are arranged in a convex arch shape toward the third heat exchange section. Integrated heat exchanger. In Article 15, The fourth heat exchanger has multiple heat exchange tubes arranged in two rows, upper and lower, and the number of heat exchangers in the lower row is reduced compared to the number of heat exchange tubes in the upper row, Integrated heat exchanger. In Article 13, The number of heat exchange tubes constituting the first and second heat exchange sections is n, which is the same and they are located on a virtual vertical line, and the number of heat exchange tubes constituting the third heat exchange section is n-1 and they are arranged on a virtual vertical line passing through the center between the heat exchange tubes constituting the second heat exchange section. Integrated heat exchanger. A boiler comprising an integrated heat exchanger according to any one of claims 1 to 17.

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