Flue gas heat exchange device for gas-fired boilers

Abstract

The application discloses a flue gas heat exchange device for a gas boiler and relates to the technical field of gas boilers.The flue gas heat exchange device comprises the following parts: a plurality of fins arranged in a first direction, each fin is repeatedly bent in a V shape in a second direction, the second direction is perpendicular to the first direction, at least one side of the fin is provided with a plurality of convex parts which play a spoiler role on flue gas, the convex parts are in a V shape, the sharp end of the lower end of the V shape faces the direction of the flue gas flow, or the convex parts are in an S shape, the two ends of the S shape respectively face the second direction, a plurality of heat exchange pipes which are arranged through the fins in the first direction, a shell, the heat exchange pipes and the fins are arranged in the shell, the shell is provided with a flue gas inlet and a flue gas outlet, a flue gas flow channel is formed between the flue gas inlet and the flue gas outlet, and the part of the flue gas flow channel which flows through the heat exchange pipes and the fins extends in a third direction as a whole.The application can solve the problems of low heat exchange efficiency and energy waste of the existing heat exchange device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas-fired boilers, in particular to a flue gas heat exchange device for a gas-fired boiler. BACKGROUND

[0002] At present, the heat loss of the gas-fired boiler is mainly the flue gas heat loss, and the flue gas temperature directly reflects the thermal efficiency of the boiler. The flue gas temperature of the domestic boiler is generally high, and the flue gas temperature under full load is above 100℃. Directly discharging high-temperature flue gas to the atmosphere is undoubtedly a waste of energy. Therefore, the current finned tube or ribbed tube flue gas heat exchanger mostly adopts the indirect contact mode between the flue gas and the heat exchange medium, so as to recover the waste heat of the flue gas.

[0003] For example, a finned heat exchanger is disclosed in Chinese patent CN214701863U, which comprises a casing, heat exchange pipes and fins for heat exchange are arranged in the casing, the fins are sleeved on the outer wall of the heat exchange pipes, two horizontal rollers are connected to the top of the inner side wall of the casing, the heat exchange pipes and the fins are located between the two rollers, the two rollers can rotate around their own axes, a dust screen is wound around each roller, one end of the dust screen is connected with the roller, and the other end is connected with a fixing device for fixing the dust screen. In the above structure, the heat exchange gas and the heat exchange liquid are exchanged through the finned tube, but the heat exchange efficiency is improved only by increasing the heat exchange area of the finned tube, and the fluid flow boundary layer is not broken, so that the heat exchange of the fluid medium participating in the heat exchange is insufficient, and the heat exchange efficiency is low.

[0004] For example, a high-efficiency finned heat exchanger for air conditioning unit is disclosed in Chinese patent CN215982881U, which comprises a high-efficiency finned heat exchanger frame, two mounting and fixing frames are connected to the two sides of the high-efficiency finned heat exchanger frame through screws, heat exchange water tanks are fixedly connected to the inner side walls of the two mounting and fixing frames, a drainage pipe is sealingly connected to the upper side of one of the heat exchange water tanks, and a water inlet pipe is sealingly connected to the lower side of the other heat exchange water tank. The outer wall of the whole outer heat conduction and heat exchange copper wire is in contact with the inner heat exchanger connecting pipe, which plays a role in heat conduction and heat dissipation. The spiral heat dissipation fins on the outer wall of the inner heat exchanger connecting pipe are in contact with the outer wall, which can well transfer the heat inside to the outside. The equidistantly arranged fixed heat conduction and heat exchange fins can support the auxiliary heat exchange water pipes and well transfer heat, further improving the heat dissipation efficiency and heat conduction performance. Similarly, in the above structure, the gas and the heat exchange fins exchange heat, but the gas side heat exchange boundary layer is not broken from the fluid heat transfer angle, and the heat exchange fluid only exchanges heat with the fins, so the heat exchange efficiency is low.

[0005] From the above, it can be seen that although heat exchange between flue gas and heat exchange medium is realized in many current schemes, the structure cannot further enhance the turbulence of flue gas, thereby causing incomplete heat exchange and low heat exchange efficiency, which causes energy waste to some extent. SUMMARY

[0006] In order to overcome the above-mentioned defects of the prior art, the technical problem to be solved by the embodiments of the present application is to provide a flue gas heat exchange device for a gas boiler, which can solve the problems of low heat exchange efficiency and energy waste of the existing heat exchange device.

[0007] The specific technical scheme of the embodiments of the present application is:

[0008] A flue gas heat exchange device for a gas boiler, the flue gas heat exchange device comprising:

[0009] a plurality of fins arranged in a first direction, each fin being repeatedly bent in a V shape along a second direction, the second direction being perpendicular to the first direction, at least one side of the fin having a plurality of protrusions for disturbing the flow of flue gas; the protrusions are in a V shape, the sharp end of the lower end of the V shape facing the direction of the flue gas flow; or the protrusions are in an S shape, the two ends of the S shape facing the second direction respectively;

[0010] a plurality of heat exchange tubes passing through the fins in the first direction;

[0011] a housing, the heat exchange tubes and the fins being arranged in the housing, the housing having a flue gas inlet and a flue gas outlet, a flue gas flow channel being formed between the flue gas inlet and the flue gas outlet, the part of the flue gas flow channel extending along a third direction, the third direction being perpendicular to the first direction and the second direction.

[0012] Preferably, the protrusions are formed by a plurality of sub-protrusions, the adjacent sub-protrusions having a gap flow channel therebetween, and the plurality of sub-protrusions have a tendency to distribute along the second direction.

[0013] Preferably, when the protrusions are in an S shape, the protrusions are formed by at least three sub-protrusions, the protrusions have at least two gap flow channels, the first gap flow channel is located at the highest point of the upward protruding arc of the S-shaped protrusion, and the second gap flow channel is located at the lowest point of the downward protruding arc of the S-shaped protrusion.

[0014] Preferably, when the protrusion is V-shaped, the protrusion is formed by at least four sub-protrusions, the protrusion has at least three gap flow channels, a first gap flow channel is located at the tip end of the V-shaped protrusion, a second gap flow channel and a third gap flow channel are respectively located at the middle of two straight segments of the V-shaped protrusion.

[0015] Preferably, in the plane formed by the first direction and the second direction, the heat exchange tube is bent and passes through the fin, and there is a gap between adjacent rows of the heat exchange tube to form at least part of the flue gas flow channel; the protrusion is located at the gap between adjacent rows of the heat exchange tube.

[0016] Preferably, a plurality of the heat exchange tubes are arranged along the third direction; adjacent heat exchange tubes are arranged in line or in a staggered manner.

[0017] Preferably, a plurality of the protrusions are arranged along the third direction.

[0018] Preferably, the heat exchange tube passes through the bending of the fin, and the protrusion is located at the plane between adjacent bending of the fin.

[0019] Preferably, the flue gas heat exchange device further comprises a water inlet pipe extending along the third direction and a water outlet pipe extending along the third direction, one end of the plurality of heat exchange tubes is connected to the water inlet pipe, the other end of the plurality of heat exchange tubes is connected to the water outlet pipe, and the water inlet of the water inlet pipe and the water outlet of the water outlet pipe are both directed toward the incoming direction of the flue gas.

[0020] The technical scheme of the present application has the following remarkable beneficial effects:

[0021] When the flue gas enters from the flue gas inlet, passes through the flue gas flow channel between two adjacent fins, and enters the heat exchanger, in the flue gas flow channel formed between the two fins, due to the blocking effect of the protrusions on the fins, part of the flue gas flows through the gap between adjacent protrusions, and the other part of the flue gas flows through the gap between the protrusion and the adjacent fin, so that the laminar boundary layer of the flue gas is destroyed, the turbulent effect is enhanced, and the convection effect of the flue gas between the fins is strengthened, thereby improving the heat exchange efficiency between the flue gas and the heat exchange medium in the heat exchange tube, and the heat exchanged flue gas flows out through the flue gas outlet.

[0022] Certain embodiments of the application are disclosed in the specification and illustrated by the accompanying drawings. The embodiments of the application described and / or shown in the specification can be readily utilized as building blocks or starting points for making and using the present application. It should be understood that the application is not limited in scope to the particular embodiments disclosed. Certain features of the embodiments of the application can be used in combination with or in place of features of other embodiments of the application. The application is defined by the claims and their equivalents. BRIEF DESCRIPTION OF DRAWINGS

[0023] The drawings described herein are for purposes of illustration only and are not intended to limit the scope of the present disclosure in any way. Additionally, the shapes and proportions of the various components depicted in the drawings are not intended to be specific, but rather are provided as illustrative examples for the purpose of understanding the present invention. Those skilled in the art will recognize that various modifications can be made to the shapes and proportions of the various components depicted in the drawings without departing from the scope of the present invention.

[0024] Figure 1 Fig. 1 is a perspective view of a flue gas heat exchange device according to an embodiment of the present invention;

[0025] Figure 2 Fig. 2 is a side view of the flue gas heat exchange device according to an embodiment of the present invention; Figure 1

[0026] Fig. 3 is a back view of the flue gas heat exchange device according to an embodiment of the present invention; Figure 3 Figure 1 Fig. 4 is a top view of the flue gas heat exchange device according to an embodiment of the present invention;

[0027] Figure 4 Figure 1 Fig. 5 is a front view of a fin according to an embodiment of the present invention;

[0028] Figure 5 Fig. 6 is a perspective view of the fin according to an embodiment of the present invention;

[0029] Figure 6 Fig. 7 is a left view of the fin according to an embodiment of the present invention;

[0030] Figure 7 Fig. 8 is a top view of the fin according to an embodiment of the present invention;

[0031] Figure 8 Fig. 9 is an enlarged view of the fin according to an embodiment of the present invention;

[0032] Figure 9 Fig. 10 is a perspective view of a fin according to another embodiment of the present invention;

[0033] Figure 10 Fig. 11 is a perspective view of the fin according to another embodiment of the present invention;

[0034] Figure 11 Fig. 12 is a schematic view of the flow of flue gas along the fin according to another embodiment of the present invention.

[0035] Reference numerals in the above drawings:

[0036] ​​1, inlet pipe; 2, outlet pipe; 3, heat exchange pipe; 4, fin; 41, convex part; 411, sub-convex part; 412, gap flow channel. DETAILED DESCRIPTION

[0037] The details of the application can be understood by the description of the drawings and the specific embodiments of the application. However, the specific embodiments of the application described herein are for the purpose of explaining the application only, and should not be understood as limiting the application in any way. Based on the teachings of the application, a skilled person can conceive any possible modification of the application, which should be considered as falling within the scope of the application. It should be noted that when an element is referred to as "provided on" another element, it can be directly on the other element or there can be a middle element. When an element is referred to as "connected" to another element, it can be directly connected to the other element or there can be a middle element. The terms "mounting", "connection", "connection" should be interpreted broadly, for example, it can be a mechanical connection or an electrical connection, it can be a connection between two elements, it can be directly connected or indirectly connected through an intermediate medium. For a person skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for the purpose of illustration only and do not indicate the only embodiment.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0039] In order to solve the problem of low heat exchange efficiency and energy waste of the existing heat exchange device, a flue gas heat exchange device for a gas boiler is provided in the present application, Figure 1 is a perspective view of the flue gas heat exchange device (excluding the shell) in the embodiment of the present application, Figure 2 is Figure 1 is a side view of the flue gas heat exchange device, Figure 3 is Figure 1 is a back view of the flue gas heat exchange device, Figure 4 is Figure 1 is a top view of the flue gas heat exchange device, Figure 5 is a front view of the fin in the first embodiment of the present application, Figure 6 is a perspective view of the fin in the first embodiment of the present application, Figure 7This is a left view of the fin in the first embodiment of the present invention. Figure 8 This is a top view of the fins in the first embodiment of the present invention. Figure 9 This is an enlarged structural diagram of the fins in the first embodiment of the present invention. Figure 10 This is a schematic diagram of the fin structure in a second embodiment of the present invention, as shown below. Figures 1 to 10 As shown, the flue gas heat exchange device may include: multiple fins 4 arranged along a first direction, each fin 4 being repeatedly bent in a V-shape along a second direction, the second direction being perpendicular to the first direction, and at least one side of the fin 4 having multiple protrusions 41 that turbulently affect the flue gas flow; the protrusions 41 are V-shaped, with the pointed end of the lower end of the V-shape facing the direction of flue gas flow; or the protrusions 41 are S-shaped, with both ends of the S-shape facing the second direction respectively; multiple heat exchange tubes 3 passing through the fins 4 along the first direction; a shell, in which the heat exchange tubes 3 and fins 4 are disposed, the shell having a flue gas inlet and a flue gas outlet, a flue gas flow channel being formed between the flue gas inlet and the flue gas outlet, and the portion of the flue gas flow channel flowing through the heat exchange tubes 3 and fins 4 extending entirely along a third direction, the third direction being perpendicular to the first and second directions.

[0040] like Figures 1 to 4 As shown, multiple fins 4 can be arranged along the first direction X, with a certain gap between adjacent fins 4. Each fin 4 can be generally rectangular in shape. Figure 1 , Figures 4 to 6 , Figure 8 As shown, each fin 4 is repeatedly bent in a V-shape along the second direction Y, which is roughly perpendicular to the first direction. The repeated V-shaped bending of the fin 4 can greatly increase the heat exchange area of ​​the fin 4, thereby increasing the heat exchange between the flue gas and the heat exchange medium in the heat exchange tube.

[0041] like Figures 5 to 10 As shown, at least one side of the fin 4 has multiple protrusions 41 that turbulently irritate the flue gas. The heat exchange tube 3 and the fin 4 are disposed within a housing, which has a flue gas inlet and a flue gas outlet, forming a flue gas flow channel between the inlet and outlet. Figure 1 As shown, the portion of the flue gas flow channel that flows through the heat exchange tube 3 and fins 4 extends along the third direction Z, which is perpendicular to the first and second directions.

[0042] Multiple heat exchange tubes 3 are inserted through the fins 4 along the first direction. For example... Figures 1 to 4 As shown, in one specific embodiment, within the plane formed by the first and second directions, the heat exchange tubes 3 meander and bend through the fins 4, with gaps between adjacent rows of heat exchange tubes 3 to form at least a portion of the flue gas flow channel. The gaps between adjacent rows of heat exchange tubes 3 and between adjacent fins 4 together form a portion of the flue gas flow channel.

[0043] As Figure 8 shown, a plurality of protrusions 41 are located at the gaps between adjacent rows of heat exchange pipes 3. As Figure 1 shown, a plurality of heat exchange pipes 3 are arranged along the third direction. The heat exchange pipes 3 pass through the bends of the fins 4, and the protrusions 41 are located at the planes between adjacent bends of the fins 4. In order to facilitate each heat exchange pipe 3 to pass through the bends of the fins 4, the adjacent heat exchange pipes 3 are arranged in an in-line or staggered manner.

[0044] When the flue gas enters from the flue gas inlet, passes through the flue gas flow channel between two adjacent fins 4, and enters the heat exchanger, in the flue gas flow channel formed between the two fins 4, due to the blocking effect of the protrusions 41 on the fins 4, part of the flue gas flows through the gap between adjacent protrusions 41, and another part of the flue gas flows through the gap between the protrusion 41 and the adjacent fin 4. In this way, the laminar boundary layer of the flue gas is destroyed, the turbulent effect is enhanced, and the convection effect of the flue gas between the fins 4 is strengthened, thereby improving the heat exchange efficiency between the flue gas and the heat exchange medium in the heat exchange pipes 3. The heat exchanged flue gas flows out through the flue gas outlet. In addition, due to the formation of the protrusions 41 on the fins 4, the heat exchange area of the fins and the flue gas is increased, which can better improve the heat exchange efficiency. The protrusions 41 can be formed by stamping processing.

[0045] As Figures 5 to 9 shown, the protrusions 41 can be V-shaped, and the sharp corners of the lower ends of the V-shaped protrusions 41 face the direction of the flue gas flow. Since the two ends of the V-shaped protrusions 41 face the direction of the flue gas flow, respectively, they can further increase the degree of destruction of the laminar boundary layer of the flue gas, further enhance the turbulent effect, and further strengthen the convection effect of the flue gas between the fins 4. In the above structure, the V-shaped protrusions 41 and the repeatedly V-shaped bent fins 4 are designed as a whole, and are combined with the heat exchange pipes 3 to form a flue gas heat exchange device without other internal connecting parts. Compared with the fin 4 type heat exchanger with increased fin 4 fixing device, this scheme is more simple and convenient in structure, and can greatly reduce the risk of device structure falling off and other devices, and has better overall structure.

[0046] Further, Figure 9 For the enlarged structure of the fins in the first embodiment of the present application, as Figure 9As shown, the V-shaped protrusion 41 can be formed by a plurality of sub-protrusions 411 with gap flow channels 412 between adjacent sub-protrusions 411, and the plurality of sub-protrusions 411 have a tendency to be distributed along the second direction. Part of the smoke flowing downward from above can flow through the gap flow channels 412, and another part of the smoke flows around the two sides of the V-shaped protrusion 41. After the flow around, the smoke and the smoke flowing through the gap flow channels 412 converge and diverge in front of the next V-shaped protrusion 41. Through the V-shaped protrusions arranged layer by layer, this way can further increase the degree of destruction of the laminar boundary layer of the smoke, and the turbulent effect can be further enhanced.

[0047] Further, when the protrusion 41 is V-shaped, the protrusion 41 is formed by at least four sub-protrusions 411. As shown, Figure 9 As shown, the protrusion 41 has at least three gap flow channels 412, the first gap flow channel 412 is located at the sharp corner end of the V-shaped protrusion 41, and the second gap flow channel 412 and the third gap flow channel 412 are located at the middle of the two straight segments of the V-shaped protrusion 41. Due to the V-shaped protrusion 41, when the smoke flows through the protrusion 41, it is blocked and guided by the straight segments of the protrusion 41, and the smoke will gather in the middle of the protrusion 41. The first gap flow channel 412 located at the sharp corner end of the V-shaped protrusion 41 can guide the smoke below the protrusion 41 to avoid excessive resistance, and at the same time, the second gap flow channel 412 and the third gap flow channel 412 can also guide the smoke above the protrusion 41 to flow below. Therefore, when the smoke flows through the protrusion, it will be divided into three streams and be divided from three different angles and flow to the two straight segments and the sharp corner end of the middle of the next protrusion 41 in turn. Not only increases the degree of destruction of the laminar boundary layer of the smoke, but also enhances the turbulent effect, and each position of the next protrusion 41 can be efficiently scoured by the smoke. Overall, it can greatly improve the heat exchange efficiency.

[0048] In another possible implementation, for example, as shown, Figure 10 The protrusion 41 can be S-shaped, and the two ends of the S-shaped protrusion 41 are respectively towards the second direction. In this way, one end of the S-shaped protrusion 41 towards the direction of the incoming smoke flow can interfere with the flow of the incoming smoke to further increase the degree of destruction of the laminar boundary layer of the smoke. The other end of the S-shaped protrusion 41 towards the direction of the smoke flow can smoothly guide the smoke to the adjacent protrusion 41, and then collide with the smoke flowing out of the one end of the adjacent protrusion 41 towards the direction of the incoming smoke flow, and the two form mutual interference to further increase the degree of destruction of the laminar boundary layer of the smoke.

[0049] Further, Figure 11 The principle diagram for the smoke flowing through the S-shaped protrusion in the second implementation of the fin in the embodiment of the present application is shown in FIG. 8. Figure 11As shown, when the protruding part 41 is in S shape, the protruding part 41 is formed by at least three sub-protruding parts 411, and the protruding part 41 has at least two gap flow channels 412, the first gap flow channel 412 is located at the highest position of the upward protruding arc of the S-shaped protruding part 41, and the second gap flow channel 412 is located at the lowest position of the downward protruding arc of the S-shaped protruding part 41. In the direction of the flue gas flow, the flue gas enters the heat exchange pipe 3 through the flue gas flow channel between two adjacent fins 4, and in the flue gas flow channel formed between the two fins 4, due to the blocking effect of the S-shaped protruding part, part of the flue gas flows through the gap flow channel 412 between the sub-protruding parts 411, and the other part of the flue gas flows around the two ends of the S-shaped protruding part 41, and after flowing around, the flue gas and the flue gas flowing through the gap flow channel 412 are confluent and divided in front of the next S-shaped protruding part 41. After passing through the S-shaped protruding part 41 arranged layer by layer, the flue gas laminar boundary layer is continuously destroyed, the turbulent effect is continuously enhanced, and the convection effect of the flue gas between the fins is strengthened, so as to improve the heat exchange efficiency between the flue gas and the heat exchange medium in the heat exchange pipe. The flue gas after heat exchange flows out through the flue gas outlet.

[0050] Holes can be provided below the protruding part 41, which are located between adjacent protruding parts 41 arranged in the third direction. In addition to the degree of destruction of the flue gas laminar boundary layer by the protruding part 41 structure, the holes enable the flue gas on one side of the fin 4 to pass through the holes after flowing through the protruding part 41 (i.e. after the flue gas laminar boundary layer is destroyed again and then starts to stabilize) to enter the other side of the fin 4, thereby further destroying the laminar boundary layer of the flue gas in the flue gas flow channel on the other side. In another way, the turbulent effect is increased again, so as to strengthen the convection effect of the flue gas between the fins 4, and thus the heat exchange efficiency between the flue gas and the heat exchange medium is further enhanced.

[0051] As a feasible solution, as shown in the drawings, Figure 1 As shown, the flue gas heat exchange device can further include a water inlet pipe 1 extending in the third direction and a water outlet pipe 2 extending in the third direction, one end of the plurality of heat exchange pipes 3 is connected with the water inlet pipe 1, and the other end of the plurality of heat exchange pipes 3 is connected with the water outlet pipe 2. The heat exchange medium in the plurality of heat exchange pipes 3 is transported through the water outlet pipe 2 and the water inlet pipe 1. Further, the water inlet of the water inlet pipe 1 and the water outlet of the water outlet pipe 2 are both directed towards the direction of the flue gas flow.

[0052] The flue gas heat exchange device in the application can destroy the boundary layer in the flue gas flow process, so that the flue gas and the heat exchange medium can better exchange heat, and deep waste heat recovery of the flue gas is realized. As a deep waste heat recovery device, the flue gas heat exchange device can not only absorb the sensible heat in the flue gas of the gas-fired boiler, but also absorb the latent heat, that is, through the high-efficiency flue gas heat exchange device, a large amount of water vapor in the flue gas is condensed into condensed water in the cooling process, and at the same time, through the water treatment device, water can be supplied to the system. In the long run, the deep waste heat recovery of the gas-fired boiler, the reuse of the condensed water, can not only play a role in energy saving and environmental protection, but also can reduce the operation cost of heating and improve the enterprise income, so it is necessary to use the deep waste heat recovery technology of flue gas in the gas-fired boiler.

[0053] All articles and references, including patent applications and publications, disclosed in the disclosure are incorporated herein by reference for all purposes. The term "consisting essentially of to describe combinations shall include the elements, ingredients, components or steps identified, and such other elements, ingredients, components or steps that do not materially affect the basic and novel characteristics of the combinations. The use of the term "comprising" or "including" to describe combinations herein is also intended to cover embodiments consisting essentially of the elements, ingredients, components or steps. By use of the term "may" herein, it is intended that any property so described can or can not be present. Multiple elements, ingredients, components or steps can be provided by a single integrated element, ingredient, component or step. Alternatively, a single integrated element, ingredient, component or step might be divided into separate multiple elements, ingredients, components or steps. To "comprise" or "include" an element or list of elements is not intended to foreclose the adding of other elements or steps to those already provided.

[0054] The above merely describes several embodiments of the present application. Although the embodiments of the present application are described above, the content is only the embodiments adopted for the purpose of facilitating the understanding of the present application, and is not used to limit the present application. Any person skilled in the art of the present application can make any modification and change in the form and details of the embodiments without departing from the spirit and scope of the present application. The patent protection scope of the present application shall be subject to the scope defined by the appended claims.

Claims

1. A flue gas heat exchange device for a gas boiler, characterized in that, The flue gas heat exchange device comprises: a plurality of fins arranged in a first direction, each fin being repeatedly bent in a V shape in a second direction perpendicular to the first direction, at least one side of the fin having a plurality of protrusions for disturbing the flue gas flow; the protrusions are in a V shape, with the pointed end of the V shape facing the direction of the flue gas flow; or the protrusions are in an S shape, with both ends of the S shape facing the second direction; a plurality of heat exchange tubes penetrating through the fins in the first direction; a housing, the heat exchange tubes and the fins being arranged in the housing, the housing having a flue gas inlet and a flue gas outlet, a flue gas flow channel being formed between the flue gas inlet and the flue gas outlet, the part of the flue gas flow channel extending through the heat exchange tubes and the fins being in a third direction perpendicular to the first direction and the second direction; the heat exchange tubes penetrating at the bending parts of the fins, the protrusions being located at the planes between adjacent bending parts of the fins; the protrusions being formed by a plurality of sub-protrusions, adjacent sub-protrusions having a gap channel therebetween, a plurality of the sub-protrusions having a tendency to be distributed in the second direction; when the protrusions are in an S shape, the protrusions are formed by at least three sub-protrusions, the protrusions having at least two gap channels, a first gap channel being located at the highest point of the upward protruding arc of the S-shaped protrusion, a second gap channel being located at the lowest point of the downward protruding arc of the S-shaped protrusion; when the protrusions are in a V shape, the protrusions are formed by at least four sub-protrusions, the protrusions having at least three gap channels, a first gap channel being located at the pointed end of the V-shaped protrusion, a second gap channel and a third gap channel being located at the middle parts of the two straight segments of the V-shaped protrusion, respectively.

2. Heat exchanger device for fumes of gas boilers according to claim 1, characterized in that, in the plane formed by the first direction and the second direction, the heat exchange tubes penetrate through the fins in a meandering manner, adjacent rows of the heat exchange tubes having gaps therebetween to form at least part of the flue gas flow channel; the protrusions being located at the gaps between adjacent rows of the heat exchange tubes.

3. Heat exchanger device for fumes of gas boilers according to claim 1, characterized in that, a plurality of the heat exchange tubes are arranged in the third direction; adjacent heat exchange tubes are arranged in a straight or staggered manner.

4. Heat exchanger device for fumes of gas boilers according to claim 3, characterized in that, a plurality of the protrusions are arranged in the third direction.

5. Heat exchanger device for fumes of gas boilers according to claim 1, characterized in that, The flue gas heat exchange device further comprises: a water inlet pipe extending in the third direction and a water outlet pipe extending in the third direction, one end of a plurality of the heat exchange tubes being connected to the water inlet pipe, the other end of a plurality of the heat exchange tubes being connected to the water outlet pipe, the water inlet of the water inlet pipe and the water outlet of the water outlet pipe both facing the direction of the flue gas flow.

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