CN222143109U - Flue gas waste heat recovery device and gas water heater - Google Patents

Abstract

The present application relates to a flue gas waste heat recovery device and a gas water heater, including a flue pipe assembly and a waste heat recovery mechanism, the flue pipe assembly includes a flue exhaust pipe, the waste heat recovery mechanism includes a gravity heat pipe and a heat exchange fin, the gravity heat pipe includes an evaporation section extending into the flue exhaust pipe and a condensation section extending out of the flue exhaust pipe, and the heat exchange fin is connected to the condensation section. By setting the gravity heat pipe and the heat exchange fin, the evaporation section can absorb the heat of the flue gas in the flue exhaust pipe, so that the heat exchange medium in the evaporation section evaporates and flows to the condensation section, the hot condensation section is connected to the heat exchange fin for heat exchange, the heat of the condensation section can be transferred to the heat exchange fin, the heat exchange fin can dissipate the heat to the room to heat the surrounding air, after the heat exchange, the steam in the condensation section is cooled and condensed to form a liquid, the condensed liquid flows along the pipe wall of the gravity heat pipe to the evaporation section, and the excess heat in the flue gas can be recovered, thereby achieving the purpose of waste heat recovery, energy saving and emission reduction.

Description

Flue gas waste heat recovery device and gas water heater

Technical Field

The application relates to the technical field of water heater accessories, in particular to a flue gas waste heat recovery device and a gas water heater.

Background

The gas water heater is a gas appliance which takes gas as fuel and transfers heat to cold water flowing through a heat exchanger in a combustion heating mode so as to achieve the purpose of preparing hot water. The flue gas generated after the combustion of the gas water heater is directly discharged into the atmosphere, but the heat carried by the flue gas is not reasonably utilized, so that energy loss is caused, and the environment protection and energy saving are not facilitated.

Disclosure of Invention

Based on the above, it is necessary to provide a flue gas waste heat recovery device and a gas water heater which can recover the redundant heat in the flue gas, thereby achieving the purposes of waste heat recovery, energy conservation and emission reduction.

A flue gas waste heat recovery device comprising:

the smoke pipe assembly comprises a smoke pipe exhaust pipe;

The waste heat recovery mechanism comprises a gravity heat pipe and heat exchange fins, wherein the gravity heat pipe comprises an evaporation section extending into the smoke pipe exhaust pipe and a condensation section extending out of the smoke pipe exhaust pipe, heat exchange media are contained in the gravity heat pipe, and the heat exchange fins are connected to the condensation section.

In the scheme, the evaporation section can absorb heat of flue gas in the flue pipe exhaust pipe through the gravity heat pipe and the heat exchange fins, so that heat exchange media in the evaporation section are evaporated and flow to the condensation section, the heat condensation section is connected with the heat exchange fins for heat exchange, the heat of the condensation section can be transferred to the heat exchange fins, heat transfer can be better realized, the heat exchange fins after heat exchange can emit heat into a room so as to heat air with low peripheral temperature, the vapor cooling in the condensation section is condensed after heat exchange, and therefore the condensed heat exchange media flow to the evaporation section along the pipe wall of the gravity heat pipe under the action of gravity, the air in the room is heated by the heat exchange fins, and the surplus heat in the flue gas can be recovered, so that the purposes of waste heat recovery, energy conservation and emission reduction are achieved.

In one embodiment, the smoke tube assembly further comprises a smoke tube air inlet tube, the smoke tube air inlet tube is sleeved outside the smoke tube air outlet tube, the central axis of the smoke tube air outlet tube is inclined towards the bottom of the smoke tube air inlet tube relative to the central axis of the smoke tube air inlet tube, and one end of the smoke tube air outlet tube, which is close to the smoke outlet, is coaxially arranged with the smoke tube air outlet tube.

Through the central axis with the relative tobacco pipe intake pipe's of tobacco pipe central axis towards the setting of tobacco pipe intake pipe bottom slope, and the one end that the tobacco pipe blast pipe is close to the exhaust port sets up with the tobacco pipe blast pipe is coaxial for after the evaporation zone heat transfer of high temperature flue gas and gravity heat pipe, the comdenstion water that the cooling produced can directly be discharged to the outside through the tobacco pipe blast pipe, prevents that the comdenstion water from flowing back to in the gas water heater, thereby damages the gas water heater.

In one embodiment, the first through holes for inserting the gravity heat pipes are formed in the smoke pipe air inlet pipe and the smoke pipe air outlet pipe;

And/or, a second through hole for inserting the gravity heat pipe is formed in the heat exchange fin, and the condensation section is connected with the second through hole in an interference fit manner.

Through condensation segment and second through-hole interference fit connection, can be better with the heat transfer of condensation segment to heat transfer fin.

In one embodiment, the waste heat recovery mechanism further comprises a vacuum heat insulation pipe, the vacuum heat insulation pipe is sleeved on the gravity heat pipe, and the vacuum heat insulation pipe is sleeved on a part of the gravity heat pipe between the smoke pipe air inlet pipe and the smoke pipe air outlet pipe.

Through setting up the vacuum thermal insulation pipe between evaporation zone and condensing zone, can prevent effectively that the heat in the evaporation zone from circulating to the in-process of condensing zone, play adiabatic effect, prevent heat loss.

In one embodiment, the waste heat recovery mechanism further comprises a mounting positioning piece, and the gravity assisted heat pipe is connected with the smoke pipe air inlet pipe and the smoke pipe air outlet pipe in a sealing mode through the mounting positioning piece.

In one embodiment, the installation positioning piece comprises a fixing part and a limiting boss arranged on the fixing part, a third through hole for inserting the vacuum heat insulation pipe or the gravity heat pipe is formed in the fixing part, and the limiting boss is provided with a limiting surface which is abutted against the outer side wall of the smoke pipe air inlet pipe.

In one embodiment, the fixing portion is in sealing connection with the vacuum insulated pipe or the gravity assisted heat pipe;

And/or, the vacuum heat insulation pipe is connected with the third through hole in an interference fit manner.

The fixing part is in sealing connection with the vacuum heat-insulating pipe or the gravity heat pipe, so that moisture or air can be effectively ensured to leak out from gaps between the vacuum heat-insulating pipe or the gravity heat pipe and the smoke pipe air inlet pipe and the smoke pipe air outlet pipe, and heat transfer between the evaporation section and the condensation section is affected. The installation locating piece adopts high temperature resistant rubber, can play sealed effect. The vacuum heat insulation pipe is connected with the third through hole in interference fit, so that the connection strength of the vacuum heat insulation pipe, the smoke pipe air inlet pipe and the smoke pipe air outlet pipe can be ensured.

In one embodiment, the gravity assisted heat pipes comprise a plurality of gravity assisted heat pipes which are axially arranged at intervals along the smoke pipe exhaust pipe;

And/or the heat exchange fins comprise a plurality of heat exchange fins, and the plurality of heat exchange fins are axially arranged at intervals along the gravity assisted heat pipe.

In one embodiment, the gravity assisted heat pipe has a first end and a second end which are oppositely arranged, the first ends of the gravity assisted heat pipes are on the same horizontal plane, the evaporation section is positioned at the second end of the gravity assisted heat pipe, and the lengths of the gravity assisted heat pipes extending into the smoke pipe exhaust pipe are the same.

The application also provides a gas water heater, which comprises the flue gas waste heat recovery device.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application.

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic diagram of a connection structure between a flue gas waste heat recovery device and a gas water heater according to an embodiment of the present application.

Fig. 2 is a schematic structural diagram of a flue gas waste heat recovery device according to an embodiment of the present application.

Fig. 3 is a structural cross-sectional view of a flue gas waste heat recovery device according to an embodiment of the present application.

Fig. 4 is a schematic diagram showing a connection structure of a waste heat recovery mechanism, a vacuum insulation pipe and an installation positioning member according to an embodiment of the present application.

Description of the reference numerals

10. 100 Parts of flue gas waste heat recovery device, 110 parts of flue gas assembly, 110 parts of flue gas exhaust pipe, 120 parts of flue gas inlet pipe, 130 parts of elbow pipe, 200 parts of waste heat recovery mechanism, 210 parts of gravity heat pipe, 211 parts of evaporation section, 212 parts of condensation section, 220 parts of heat exchange fin, 300 parts of vacuum heat insulation pipe, 400 parts of installation positioning piece, 410 parts of fixing part, 420 parts of limiting boss, 421 parts of limiting surface, 20 parts of gas water heater.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

In the description of the present application, it should be understood that, if any, these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., are used herein with respect to the orientation or positional relationship shown in the drawings, these terms refer to the orientation or positional relationship for convenience of description and simplicity of description only, and do not indicate or imply that the apparatus or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application.

Furthermore, the terms "first," "second," and the like, if any, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the terms "plurality" and "a plurality" if any, mean at least two, such as two, three, etc., unless specifically defined otherwise.

In the present application, unless explicitly stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly. For example, they may be fixedly connected, detachably connected or integrally formed, mechanically connected, electrically connected, directly connected or indirectly connected through an intermediate medium, and communicated between two elements or the interaction relationship between two elements unless clearly defined otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present application, unless expressly stated or limited otherwise, the meaning of a first feature being "on" or "off" a second feature, and the like, is that the first and second features are either in direct contact or in indirect contact through an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that if an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. If an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein, if any, are for descriptive purposes only and do not represent a unique embodiment.

Referring to fig. 1, an embodiment of the present application provides a flue gas waste heat recovery device 10 for cooperating with a gas water heater 20 to recover heat in flue gas discharged from the gas water heater 20.

Referring to fig. 1 and 2, the flue gas waste heat recovery device 10 includes a flue pipe assembly 100 and a waste heat recovery mechanism 200, wherein the flue pipe assembly 100 includes a flue pipe exhaust pipe 110, and the flue pipe exhaust pipe 110 is used for communicating with a flue outlet of the gas water heater 20. Specifically, the smoke tube exhaust pipe 110 has a first end and a second end disposed opposite to each other, the first end being adapted to communicate with the exhaust port of the gas water heater 20, and the second end being adapted to communicate with the air.

Referring to fig. 2, 3 and 4, the waste heat recovery mechanism 200 includes a gravity assisted heat pipe 210 and heat exchange fins 220, wherein the gravity assisted heat pipe 210 includes an evaporation section 211 extending into the flue pipe exhaust pipe 110 and a condensation section 212 extending out of the flue pipe exhaust pipe 110. The gravity assisted heat pipe 210 contains a heat exchange medium. Heat exchange fins 220 are connected to condensing section 212. The evaporation section 211 can absorb the heat of the flue gas in the flue pipe exhaust pipe 110, so that the heat exchange medium in the evaporation section 211 is evaporated and flows to the condensation section 212, and the condensation section 212 is connected with the heat exchange fins 220 for heat exchange. Illustratively, the condensing section 212 and the heat exchanging fins 220 are made of copper, which can perform the function of heat conduction and dissipation. The evaporator section 211 is made of stainless steel.

The gravity assisted heat pipe 210 has a working principle that a proper amount of heat exchange medium is filled in the gravity assisted heat pipe 210, the heat exchange medium is located in an evaporation section 211 of the gravity assisted heat pipe 210 before evaporation, the heat exchange medium in the evaporation section 211 is evaporated after the evaporation section 211 is heated, a large amount of evaporation latent heat is absorbed, steam rapidly flows to a condensation section 212 under a tiny pressure difference, after cooling, the steam is condensed on the inner wall of the condensation section 212 to form liquid, a large amount of evaporation latent heat is released during the condensation process, and the condensed heat exchange medium flows to the evaporation section 211 along the pipe wall of the gravity assisted heat pipe 210 under the action of gravity. The above operation can be continuously circulated at a high speed, and heat is continuously supplied from the evaporation section 211 to the condensation section 212 of the gravity assisted heat pipe 210.

When the gas water heater 20 is burning, the high temperature smoke generated after the gas burning will flow to the smoke tube exhaust tube 110 through the smoke outlet, and the evaporation section 211 of the gravity assisted heat pipe 210 is disposed in the smoke tube exhaust tube 110. The heat exchange medium in the evaporation section 211 can absorb the heat of the high temperature flue gas in the flue pipe exhaust pipe 110 to become a vapor state and can rapidly flow to the condensation section 212. And the condensing section 212 and the heat exchange fins 220 are connected for heat exchange, and the heat of the condensing section 212 can be transferred to the heat exchange fins 220, so that the heat transfer can be better realized. The heat exchanging fin 220 after heat exchanging may radiate heat into a room to heat ambient low temperature air.

After the heat is dissipated indoors, the vapor in the condensation section 212 is cooled and condensed to be liquid, and the condensed heat exchange medium flows to the evaporation section 211 along the pipe wall of the gravity assisted heat pipe 210 under the action of gravity. The indoor air is heated by the heat exchange fins 220 continuously, and the surplus heat in the flue gas can be recovered, so that the purposes of waste heat recovery, energy conservation and emission reduction are achieved.

It should be noted that the application of the flue gas waste heat recovery device 10 is not limited in the present application, and the heat recovered by the flue gas waste heat recovery device 10 may have various applications, such as heating the room in winter, cooperating with a kitchen to construct a disinfection cabinet, or the like, or a heat insulation pipe with a fan may be added at one end of the gravity assisted heat pipe 210 provided with the heat exchange fin 220 to guide the heat to other places, or the like.

Through setting up gravity heat pipe 210 and heat transfer fin 220, evaporation zone 211 can absorb the heat of flue gas in the tobacco pipe blast pipe 110, make the heat transfer medium in the evaporation zone 211 evaporate, and flow to condensation zone 212, heat condensation zone 212 carries out the connection heat transfer with heat transfer fin 220, the heat of condensation zone 212 can transmit to heat transfer fin 220, can realize the transfer heat better, heat transfer fin 220 after the heat transfer can give off the heat to indoor, with the air of heating peripheral low temperature, the steam cooling in condensation zone 212 condenses after the heat transfer, thereby condense into liquid, the heat transfer medium after the condensation flows to evaporation zone 211 under the effect of gravity heat pipe 210's pipe wall, constantly circulate, indoor air can be heated by heat transfer fin 220, thereby realize retrieving unnecessary heat in the flue gas, thereby reach waste heat recovery, energy saving and emission reduction's purpose.

The flue gas waste heat recovery device 10 according to the embodiment of the present utility model is described in detail below with reference to the accompanying drawings.

Referring to fig. 1, 2, 3 and 4, according to some embodiments of the present application, the smoke tube assembly 100 further includes a smoke tube intake tube 120, and the smoke tube intake tube 120 is sleeved outside the smoke tube exhaust tube 110. The central axis of the smoke tube exhaust pipe 110 is inclined towards the bottom of the smoke tube intake pipe 120 relative to the central axis of the smoke tube intake pipe 120, and one end of the smoke tube exhaust pipe 110 close to the smoke outlet is coaxially arranged with the smoke tube exhaust pipe 110.

Specifically, the central axis of the smoke tube inlet pipe 120 is parallel to the horizontal line. An included angle is formed between the central axis of the smoke inlet pipe 120 and the central axis of the smoke outlet pipe 110. It should be noted that, the included angle between the central axis of the smoke tube air inlet tube 120 and the central axis of the smoke tube air outlet tube 110 is not limited in the present application, and can be set according to the actual use requirement.

The smoke pipe air inlet pipe 120 is used for communicating with an air inlet of the gas water heater 20, fresh air can enter the gas water heater 20 through the smoke pipe air inlet pipe 120 and the air inlet in sequence, and high temperature after combustion of the gas water heater 20 is discharged to the atmosphere through the smoke pipe air outlet pipe 110 and the smoke outlet in sequence. The smoke inlet pipe 120 and the smoke outlet pipe 110 are not communicated with each other.

Through the central axis with the relative tobacco pipe intake pipe 120 of the central axis of tobacco pipe blast pipe 110 towards the slope of tobacco pipe intake pipe 120 bottom setting, and the one end that the tobacco pipe blast pipe 110 is close to the exhaust port sets up with the tobacco pipe blast pipe 110 concentric center for after the evaporation zone 211 heat transfer of high temperature flue gas and gravity heat pipe 210, the comdenstion water that the cooling produced can directly be discharged to the outside through the tobacco pipe blast pipe 110, prevents that the comdenstion water from flowing back to in the gas water heater 20, thereby damages gas water heater 20.

The smoke tube assembly 100 further comprises a bent tube 130, one end of the bent tube 130 is communicated with the smoke tube exhaust tube 110, and the other end of the bent tube 130 is communicated with the smoke outlet of the gas water heater 20. The smoke tube air inlet pipe 120 is sleeved outside the bent pipe 130. Specifically, one end of the elbow 130 has a first central axis. The other end of the bent pipe 130 has a second central axis, and the first central axis is perpendicular to the second central axis.

Referring to fig. 2, 3 and 4, according to some embodiments of the application, the waste heat recovery mechanism 200 further includes a vacuum thermal insulation pipe 300, the vacuum thermal insulation pipe 300 is sleeved on the gravity thermal pipe 210, and the vacuum thermal insulation pipe 300 is sleeved on a part of the gravity thermal pipe 210 between the smoke tube air inlet pipe 120 and the smoke tube air outlet pipe 110. By providing the vacuum insulation pipe 300 at the portion between the smoke inlet pipe 120 and the smoke outlet pipe 110, heat in the evaporation section 211 can be effectively prevented from flowing to the condensation section 212, thereby having an insulation effect and preventing heat loss.

Referring to fig. 2, 3 and 4, according to some embodiments of the application, optionally, the smoke inlet pipe 120 and the smoke outlet pipe 110 are provided with first through holes for inserting the gravity assisted heat pipe 210. In this embodiment, the vacuum insulation piping 300 is located between the smoke inlet pipe 120 and the smoke outlet pipe 110 and the gravity assisted heat pipe 210. A partial vacuum thermal insulation pipe 300 is arranged between the smoke inlet pipe 120 and the smoke outlet pipe 110, and the vacuum thermal insulation pipe 300 can play a role of thermal insulation to prevent heat loss from a gap between the smoke inlet pipe 120 and the smoke outlet pipe 110.

Referring to fig. 2, 3 and 4, according to some embodiments of the present application, optionally, a second through hole is formed on the heat exchange fin 220 for inserting the gravity assisted heat pipe 210, and the condensation section 212 is connected with the second through hole in an interference fit manner. Through condensation segment 212 and second through-hole interference fit connection, can be better with condensation segment 212's heat transfer to heat transfer fin 220.

Referring to fig. 2, 3 and 4, according to some embodiments of the application, the waste heat recovery mechanism 200 further includes an installation positioning member 400, and the gravity assisted heat pipe 210 is connected to the smoke pipe intake pipe 120 and the smoke pipe exhaust pipe 110 by the installation positioning member 400 in a sealing manner.

Specifically, the installation positioning member 400 includes a fixing portion 410 and a limiting boss 420 disposed on the fixing portion 410, the fixing portion 410 is provided with a third through hole for inserting the vacuum insulation tube 300, and the limiting boss 420 has a limiting surface 421 abutted against an outer side wall of the smoke tube air inlet tube 120.

The limiting boss 420 is connected to the upper end of the fixing portion 410. The fixing portion 410 is provided around the outside of the vacuum insulation tube 300. The limiting boss 420 can abut against the outer sidewall of the smoke tube air inlet pipe 120, thereby limiting the vacuum insulation tube 300. The outer contour of the limiting surface 421 is the same as the outer sidewall of the smoke tube air inlet pipe 120.

The fixing portion 410 is in sealing connection with the vacuum thermal insulation pipe 300, so that moisture or air can be effectively ensured to leak out from the gaps between the vacuum thermal insulation pipe 300 and the smoke pipe air inlet pipe 120 and the smoke pipe air outlet pipe 110, thereby influencing heat transfer between the evaporation section 211 and the condensation section 212. The installation locating piece 400 adopts high temperature resistant rubber, and can play a role in sealing.

Referring to fig. 2, 3 and 4, optionally, vacuum insulated pipe 300 is connected with a third through-hole interference fit, according to some embodiments of the present application. The vacuum thermal insulation pipe 300 is connected with the third through hole in an interference fit manner, so that the connection strength of the vacuum thermal insulation pipe 300 with the smoke pipe air inlet pipe 120 and the smoke pipe air outlet pipe 110 can be ensured.

Referring to fig. 2, 3 and 4, according to some embodiments of the application, optionally, the gravity assisted heat pipes 210 include a plurality of gravity assisted heat pipes 210 axially spaced along the smoke stack exhaust pipe 110. The heat exchange fins 220 include a plurality of heat exchange fins 220 axially spaced along the gravity assisted heat pipe 210. It should be understood that the number of the gravity assisted heat pipes 210 and the heat exchange fins 220 is not limited, and can be set according to the actual use requirement.

Referring to fig. 2, 3 and 4, according to some embodiments of the application, optionally, the gravity assisted heat pipes 210 have a first end and a second end disposed opposite to each other, the first ends of the gravity assisted heat pipes 210 are on the same horizontal plane, the evaporation section 211 is located at the second end of the gravity assisted heat pipe 210, and the lengths of the gravity assisted heat pipes 210 extending into the smoke pipe exhaust pipe 110 are the same. Specifically, since the central axis of the smoke tube exhaust pipe 110 is inclined toward the bottom of the smoke tube intake pipe 120 with respect to the central axis of the smoke tube intake pipe 120, the length of each gravity assisted heat pipe 210 is different. Along the direction away from the fume outlet, the length of the gravity assisted heat pipe 210 is gradually increased to ensure that the gravity assisted heat pipe 210 and the high-temperature fume have enough heat exchange contact surface, thereby improving the recovery utilization rate of the fume waste heat.

The application also provides a gas water heater 20, which comprises the flue gas waste heat recovery device 10.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the claims. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims (10)

1. A flue gas waste heat recovery device, comprising:

a smoke tube assembly (100), the smoke tube assembly (100) comprising a smoke tube exhaust (110);

Waste heat recovery mechanism (200), waste heat recovery mechanism (200) include gravity heat pipe (210) and heat transfer fin (220), gravity heat pipe (210) are including stretching into evaporation zone (211) in tobacco pipe blast pipe (110) and stretch out condensation section (212) outside tobacco pipe blast pipe (110), gravity heat pipe (210) are interior to have contained the heat transfer medium, heat transfer fin (220) connect in condensation section (212).

2. The flue gas waste heat recovery device according to claim 1, wherein the flue gas pipe assembly (100) further comprises a flue gas pipe inlet (120), the flue gas pipe inlet (120) is sleeved outside the flue gas pipe outlet (110), and a central axis of the flue gas pipe outlet (110) is inclined towards the bottom of the flue gas pipe inlet (120) relative to a central axis of the flue gas pipe inlet (120).

3. The flue gas waste heat recovery device according to claim 2, wherein the flue gas pipe intake pipe (120) and the flue gas pipe exhaust pipe (110) are provided with first through holes for inserting the gravity assisted heat pipes (210);

And/or, a second through hole for the gravity heat pipe (210) to be inserted is formed in the heat exchange fin (220), and the condensation section (212) is connected with the second through hole in an interference fit manner.

4. The flue gas waste heat recovery device according to claim 2, wherein the waste heat recovery mechanism (200) further comprises a vacuum heat insulation pipe (300), and the vacuum heat insulation pipe (300) is sleeved on a part of the gravity heat pipe (210) between the flue pipe air inlet pipe (120) and the flue pipe air outlet pipe (110).

5. The flue gas waste heat recovery device according to claim 4, wherein the waste heat recovery mechanism (200) further comprises a mounting positioning member (400), and the gravity assisted heat pipe (210) is connected to the flue pipe inlet pipe (120) and the flue pipe outlet pipe (110) in a sealing manner by the mounting positioning member (400).

6. The flue gas waste heat recovery device according to claim 5, wherein the installation positioning member (400) comprises a fixing portion (410) and a limiting boss (420) arranged on the fixing portion (410), the fixing portion (410) is provided with a third through hole for inserting the vacuum thermal insulation pipe (300), and the limiting boss (420) is provided with a limiting surface (421) abutted against the outer side wall of the flue pipe air inlet pipe (120).

7. The flue gas waste heat recovery device according to claim 6, wherein the fixing portion (410) is hermetically connected to the vacuum heat insulation pipe (300) or the gravity heat pipe (210);

And/or, the vacuum insulation tube (300) is connected with the third through hole in an interference fit manner.

8. The flue gas waste heat recovery device according to claim 1, wherein the gravity assisted heat pipes (210) comprise a plurality of gravity assisted heat pipes (210) axially spaced along the flue pipe exhaust pipe (110);

And/or the heat exchange fins (220) comprise a plurality of heat exchange fins (220) which are axially arranged at intervals along the gravity assisted heat pipe (210).

9. The flue gas waste heat recovery device according to claim 1, wherein the gravity assisted heat pipes (210) have a first end and a second end which are disposed opposite to each other, the first ends of the gravity assisted heat pipes (210) are on the same horizontal plane, the evaporation section (211) is located at the second end of the gravity assisted heat pipes (210), and lengths of the gravity assisted heat pipes (210) extending into the flue pipe exhaust pipe (110) are the same.

10. A gas water heater characterized by comprising a flue gas waste heat recovery device (10) according to any one of claims 1 to 9.