CN220649134U - Flue gas waste heat recovery device - Google Patents

Abstract

The utility model provides a flue gas waste heat recovery device, which relates to the technical field of waste heat recovery, and comprises a chimney, a heat collector, a heat exchanger, a circulating pipeline and a heat exchange pipeline, wherein the chimney is provided with a waste heat recovery section and is used for discharging flue gas, the heat collector is arranged in the waste heat recovery section and is used for realizing primary heat exchange with the flue gas, the heat exchanger is arranged outside the chimney and is connected with the heat collector through the circulating pipeline so as to realize secondary heat exchange between the heat exchanger and the heat collector, a first circulating medium is filled in the circulating pipeline and is used for transmitting heat collected by the heat collector to the heat exchanger, the heat exchange pipeline is connected with the heat exchanger and is used for being connected to heat utilization equipment, and a second circulating medium is filled in the heat exchange pipeline. Compared with the prior art, the flue gas waste heat recovery device provided by the utility model can recover the flue gas waste heat, extract heat energy from the discharged flue gas, and is good in recovery effect, environment-friendly and energy-saving.

Description

Flue gas waste heat recovery device

Technical Field

The utility model relates to the technical field of waste heat recovery, in particular to a flue gas waste heat recovery device.

Background

In the production link of metal forging processing, a large amount of heat is required to be utilized. In addition to the heating of the metal forging and the heat preservation of the hearth of the forging furnace, a great part of heat is directly discharged to the atmosphere through the chimney of the forging furnace, so that a great amount of energy is wasted and heat pollution is caused.

Disclosure of Invention

The utility model aims to provide a flue gas waste heat recovery device which can recover flue gas waste heat, extract heat energy from discharged flue gas, and has good recovery effect, environmental protection and energy conservation.

Embodiments of the utility model may be implemented as follows:

in a first aspect, the utility model provides a flue gas waste heat recovery device, which comprises a chimney, a heat collector, a heat exchanger, a circulation pipeline and a heat exchange pipeline, wherein the chimney is provided with a waste heat recovery section and is used for discharging flue gas, the heat collector is arranged at the waste heat recovery section and is used for realizing primary heat exchange with the flue gas, the heat exchanger is arranged outside the chimney and is connected with the heat collector through the circulation pipeline so as to realize secondary heat exchange between the heat exchanger and the heat collector, a first circulation medium is filled in the circulation pipeline and is used for transmitting heat collected by the heat collector to the heat exchanger, the heat exchange pipeline is connected with the heat exchanger and is used for being connected to heat utilization equipment, and a second circulation medium is filled in the heat exchange pipeline and is used for transmitting heat collected by the heat exchanger to the heat utilization equipment.

In an alternative embodiment, the waste heat recovery section comprises a main flue and a bypass flue, the main flue is used for discharging flue gas outwards, and a first smoke discharge regulating valve is arranged on the main flue and is used for conducting or cutting off the main flue; the bypass flue is connected to the main flue, the air inlet end and the air outlet end of the bypass flue are respectively connected to two sides of the first smoke discharging adjusting valve, the bypass flue is provided with a second smoke discharging adjusting valve, the second smoke discharging adjusting valve is used for conducting or cutting off the bypass flue, and the heat collector is arranged on the bypass flue and is located on the air outlet side of the second smoke discharging adjusting valve.

In an alternative embodiment, the first smoke-discharging control valve has a first opening valve plate for controlling the opening of the first smoke-discharging control valve, and the second smoke-discharging control valve has a second opening valve plate for controlling the opening of the second smoke-discharging control valve.

In an alternative embodiment, an air guiding component is further arranged at the outlet of the chimney or on the bypass flue, and the air guiding component is used for balancing the air pressure in the chimney.

In an alternative embodiment, the circulation pipeline comprises a first medium inlet pipe and a first medium outlet pipe, two ends of the first medium inlet pipe are respectively connected to the inlet of the heat collector and the outlet of the heat exchanger, two ends of the first medium outlet pipe are respectively connected to the outlet of the heat collector and the inlet of the heat exchanger, and the first medium inlet pipe and/or the first medium outlet pipe are/is further provided with a circulation switch.

In an alternative embodiment, the first medium inlet pipe and/or the first medium outlet pipe is provided with a first driving member, so that the first circulating medium circulates between the heat collector and the heat exchanger.

In an alternative embodiment, the circulation pipeline further comprises a bypass pipe, two ends of the bypass pipe are respectively connected to the first medium inlet pipe and the first medium outlet pipe, the first driving piece is arranged between the bypass pipe and the heat collector, a bypass switch is arranged on the bypass pipe, and the circulation switch is located between the bypass pipe and the heat exchanger.

In an alternative embodiment, the heat exchange pipeline comprises a second medium inlet pipe and a second medium outlet pipe, one end of the second medium inlet pipe is connected with the inlet of the heat exchanger, the other end of the second medium inlet pipe is used for being connected to the outlet of the heat utilization device, one end of the second medium outlet pipe is connected with the outlet of the heat exchanger, and the other end of the second medium outlet pipe is used for being connected to the inlet of the heat utilization device.

In an alternative embodiment, a second driving member is further arranged on the second medium inlet pipe and/or the second medium outlet pipe, so that the second circulating medium circulates between the heat exchanger and the heat utilization device.

In an alternative embodiment, the first medium inlet pipe and the first medium outlet pipe are provided with a pressure detector and an automatic pressure reducer.

The beneficial effects of the embodiment of the utility model include, for example:

according to the flue gas waste heat recovery device provided by the embodiment of the utility model, the heat collector is arranged at the waste heat recovery section of the chimney, so that primary heat exchange with flue gas can be realized, and then the heat collector is connected with the heat exchanger through the circulating pipeline, so that secondary heat exchange between the heat collector and the heat exchanger is realized, and the heat exchanger is connected with heat utilization equipment through the heat exchange pipeline after heat exchange, so that heat supply is realized. Compared with the prior art, the flue gas waste heat recovery device provided by the embodiment of the utility model can recover the flue gas waste heat, extract heat energy from the discharged flue gas, and is good in recovery effect, environment-friendly and energy-saving.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present utility model and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a flue gas waste heat recovery device according to a first embodiment of the present utility model;

fig. 2 is a schematic structural diagram of a flue gas waste heat recovery device according to a second embodiment of the present utility model.

Icon: 100-a flue gas waste heat recovery device; 110-chimney; 111-a main flue; 112-bypass flue; 113-a first fume-extraction regulating valve; 114-a second smoke discharge regulating valve; 120-heat collector; 130-a heat exchanger; 140-a circulation line; 141-a first medium inlet pipe; 142-a first media exit tube; 143-a circulation switch; 144-a first driver; 145-bypass tube; 146-bypass switch; 147-pressure gauge; 150-a heat exchange pipeline; 151-a second medium inlet pipe; 152-a second media exit tube; 153-a second drive; 160-induced air assembly.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. The components of the embodiments of the present utility model generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the utility model, as presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

In the description of the present utility model, it should be noted that, if the terms "upper", "lower", "inner", "outer", and the like indicate an azimuth or a positional relationship based on the azimuth or the positional relationship shown in the drawings, or the azimuth or the positional relationship in which the inventive product is conventionally put in use, it is merely for convenience of describing the present utility model and simplifying the description, and it is not indicated or implied that the apparatus or element referred to must have a specific azimuth, be configured and operated in a specific azimuth, and thus it should not be construed as limiting the present utility model.

Furthermore, the terms "first," "second," and the like, if any, are used merely for distinguishing between descriptions and not for indicating or implying a relative importance.

As disclosed in the background art, in the production process of forging metal, the chimney 110 is generally utilized to directly discharge the flue gas with a large amount of heat, which causes a large amount of energy waste and pollution.

Further, in the prior art, a scheme of recovering the waste heat of the flue gas by using the spraying device appears, however, the conventional waste heat recovery scheme generally only adopts one-time heat exchange, namely, the waste heat of the flue gas is directly exchanged for recycling, the waste heat recovery stability is poor, the heat exchange medium is difficult to change, and the limitation is larger.

In order to solve the above-mentioned problems, the present utility model provides a novel flue gas waste heat recovery device 100, and it should be noted that the features of the embodiments of the present utility model may be combined with each other without collision.

First embodiment

Referring to fig. 1, the embodiment provides a flue gas waste heat recovery device 100, which can recover flue gas waste heat, extract heat energy from discharged flue gas, and has the advantages of good recovery effect, environmental protection, energy saving, better controllability, and more stable and reliable heat supply.

The flue gas waste heat recovery device 100 provided in this embodiment includes a chimney 110, a heat collector 120, a heat exchanger 130, a circulation pipeline 140 and a heat exchange pipeline 150, where the chimney 110 has a waste heat recovery section and is used for discharging flue gas, the heat collector 120 is disposed in the waste heat recovery section and is used for realizing primary heat exchange with the flue gas, the heat exchanger 130 is disposed outside the chimney 110 and is connected with the heat collector 120 through the circulation pipeline 140, so that the heat exchanger 130 and the heat collector 120 realize secondary heat exchange, the circulation pipeline 140 is filled with a first circulation medium, the first circulation medium is used for transferring heat collected by the heat collector 120 to the heat exchanger 130, the heat exchange pipeline 150 is connected with the heat exchanger 130 and is used for being connected to a heat utilization device, and the heat exchange pipeline 150 is filled with a second circulation medium, and the second circulation medium is used for transferring heat collected by the heat exchanger 130 to the heat utilization device.

The chimney 110 in this embodiment refers to a structure of flue gas emission, which is connected to the kiln and discharges flue gas in the kiln. The pit furnace can be a furnace body of a heat treatment link, such as a furnace body in a metal forging process. Through set up heat collector 120 at chimney 110's waste heat recovery section, can realize the primary heat transfer with the flue gas, then heat collector 120 is connected with heat exchanger 130 through circulation pipeline 140 for heat collector 120 realizes the secondary heat transfer with heat exchanger 130, is connected with heat equipment through heat exchange pipeline 150 after the heat exchanger 130 heat transfer, realizes the heat supply, and the flue gas waste heat recovery device 100 that this embodiment provided can retrieve the flue gas waste heat, draws heat energy in the flue gas of discharging, and recovery effect is good, environmental protection, energy-conservation.

It is noted that the heat collector 120 in this embodiment may be a heat pipe type heat collector 120, which contacts the flue gas through a heat pipe, so that the flue gas exchanges heat with the first circulating medium. Meanwhile, the heat exchanger 130 in the present embodiment may be a conventional heat exchanger 130, such as a heat pipe type heat exchanger 130 or a plate type heat exchanger 130, so as to implement heat exchange between the first circulation medium and the second circulation medium.

The waste heat recovery section comprises a main flue 111 and a bypass flue 112, the main flue 111 is used for discharging flue gas outwards, a first smoke discharge regulating valve 113 is arranged on the main flue 111, and the first smoke discharge regulating valve 113 is used for conducting or cutting off the main flue 111; the bypass flue 112 is connected to the main flue 111, and the air inlet end and the air outlet end of the bypass flue 112 are respectively connected to two sides of the first smoke exhaust adjusting valve 113, the bypass flue 112 is provided with a second smoke exhaust adjusting valve 114, the second smoke exhaust adjusting valve 114 is used for conducting or cutting off the bypass flue 112, and the heat collector 120 is arranged on the bypass flue 112 and is located at the air outlet side of the second smoke exhaust adjusting valve 114. Specifically, the main flue 111 is a vertically upward flue structure, and the bypass flue 112 is a bent flue structure and is disposed beside the main flue 111, wherein the waste heat recovery section may be disposed near the outlet of the chimney 110.

It should be noted that, in this embodiment, the bypass flue 112 is in a transverse U-shaped structure, and the bypass flue 112 and the main flue 111 are integrally disposed, the air inlet end of the bypass flue 112 is located at the lower side, the air outlet end is located at the upper side, the first smoke exhaust adjusting valve 113 is located between the air inlet end and the air outlet end of the bypass flue 112, the second smoke exhaust adjusting valve 114 is located between the heat collector 120 and the air inlet end on the bypass flue 112, and by setting the first smoke exhaust adjusting valve 113 and the second smoke exhaust adjusting valve 114, the smoke can be adjusted to selectively enter the main flue 111 or the bypass flue 112, so that the controllability is better.

Specifically, when the flue gas is discharged actually, the first flue gas regulating valve 113 and the second flue gas regulating valve 114 may be selectively opened, so that the high-temperature flue gas is led into the main flue 111 or the bypass flue 112, and thus, the waste heat recovery can be selectively performed, for example, when the kiln begins to discharge the flue gas, the first flue gas regulating valve 113 may be opened and the second flue gas regulating valve 114 may be closed because the temperature is lower, so that the flue gas only passes through the main flue 111, and when the temperature is raised, the second flue gas regulating valve 114 may be opened and the first flue gas regulating valve 113 may be closed, so that the flue gas only passes through the bypass flue 112 and the heat in the flue gas is collected through the heat collector 120. Or, when the heat collector 120, the heat exchanger 130 or the pipeline is overhauled, the second smoke discharging adjusting valve 114 can be closed, so that the smoke is prevented from influencing the overhauling.

In the present embodiment, the first smoke-discharging adjustment valve 113 has a first opening valve plate for adjusting the opening of the first smoke-discharging adjustment valve 113, and the second smoke-discharging adjustment valve 114 has a second opening valve plate for adjusting the opening of the second smoke-discharging adjustment valve 114. Specifically, the first smoke discharge adjusting valve 113 and the second smoke discharge adjusting valve 114 not only have the function of guiding the smoke passage, but also have the function of adjusting the smoke flow, and the smoke flow in the main flue 111 and the bypass flue 112 can be adjusted more freely through the adjustment of the first opening valve plate and the second opening valve plate, so that the waste heat recovery amount is adjusted, and the overheat of the heat collector 120 is avoided.

It should be noted that, in this embodiment, the circulation pipeline 140 is filled with a first circulation medium, which may be water or other refrigerant medium, the first circulation medium has good heat conducting performance, the first circulation medium may flow between the heat collector 120 and the heat exchanger 130 by means of the circulation pipeline 140, where when the first circulation medium is left in the heat collector 120, heat exchange can be performed between the heat collector 120 and the flue gas flowing through the bypass flue 112, so as to collect heat in the flue gas, after heat exchange, the first circulation medium may flow to the heat exchanger 130, and then exchange with the second circulation medium flowing through the heat exchanger 130, so that heat is transferred to the second circulation medium, and heat recovery and utilization of heat passing through two heat exchanges are achieved.

The circulation line 140 includes a first medium inlet pipe 141 and a first medium outlet pipe 142, both ends of the first medium inlet pipe 141 are respectively connected to an inlet of the heat collector 120 and an outlet of the heat exchanger 130, both ends of the first medium outlet pipe 142 are respectively connected to an outlet of the heat collector 120 and an inlet of the heat exchanger 130, and a circulation switch 143 is further provided on the first medium inlet pipe 141 and/or the first medium outlet pipe 142. Specifically, the circulation switch 143 is disposed on the first medium inlet pipe 141, and by providing the circulation switch 143, it is possible to control whether the first circulation medium flows to the heat exchanger 130, thereby making the control of the heat collector 120 and the heat exchanger 130 more reliable. Wherein the circulation switch 143 is located between the bypass pipe 145 and the heat exchanger 130.

In the present embodiment, a first driving member 144 is provided on the first medium inlet pipe 141 and/or the first medium outlet pipe 142 to circulate the first circulating medium between the heat collector 120 and the heat exchanger 130. Specifically, the first driving member 144 is disposed on the first medium outlet pipe 142, and the first driving member 144 may be a pressure pump, and is capable of driving the first circulating medium to flow in the circulating pipeline 140, thereby improving fluidity and heat transfer efficiency thereof.

Further, the circulation line 140 further includes a bypass pipe 145, both ends of the bypass pipe 145 are connected to the first medium inlet pipe 141 and the first medium outlet pipe 142, respectively, the first driving member 144 is disposed between the bypass pipe 145 and the heat collector 120, and a bypass switch 146 is disposed on the bypass pipe 145, and the circulation switch 143 is disposed between the bypass pipe and the heat exchanger 130. Specifically, by providing the bypass pipe 145 and matching with the use of the bypass switch 146, the first circulating medium can flow in the heat exchanger 130 or the bypass pipe 145, so that when the heat exchanger 130 has no heat supply requirement or the flue gas waste heat recovery device 100 needs to be stopped, the first circulating medium is ensured to be still in a flowing state, and the heat collector 120 is placed under the condition of overheating.

Specifically, when the flue gas waste heat recovery device 100 is normally used, the bypass switch 146 is in the off state, the circulation switch 143 is in the on state, and at this time, the first circulation medium flows between the heat collector 120 and the heat exchanger 130, so as to realize normal heat exchange and heat supply. When the heat utilization device has no heat demand, or the flue gas waste heat recovery device 100 needs to be shut down for maintenance, in order to prevent the first circulating medium in the heat collector 120 from overheating due to heat radiation, a potential safety hazard is caused, at this time, the bypass switch 146 can be turned on, the circulating switch 143 can be adjusted to be in a closed state, the first driving member 144 is turned on, so that the first circulating medium in the heat collector 120 is in a flowing state, and thereby the heat collector 120 is prevented from overheating when the flue gas waste heat recovery device 100 is shut down.

In this embodiment, the heat exchange pipeline 150 includes a second medium inlet pipe 151 and a second medium outlet pipe 152, one end of the second medium inlet pipe 151 is connected to the inlet of the heat exchanger 130, the other end is used for being connected to the outlet of the heat using device, one end of the second medium outlet pipe 152 is connected to the outlet of the heat exchanger 130, and the other end is used for being connected to the inlet of the heat using device. Specifically, the second medium inlet pipe 151 and the second medium outlet pipe 152 are connected to a heat using device, which may be a hot water supply device or a heat treatment preheating device, etc., to thereby realize heat supply, and are not particularly limited herein.

In this embodiment, a second driving member 153 is further disposed on the second medium inlet pipe 151 and/or the second medium outlet pipe 152 to circulate the second circulating medium between the heat exchanger 130 and the heat consuming device. Specifically, a second driving member 153 may be provided on the second medium outlet pipe 152, and the second driving member 153 may also be a pressure pump, so that a pumping function for the second circulating medium can be achieved.

The working process and principle of the flue gas waste heat recovery device 100 provided in this embodiment are as follows:

when the high-temperature flue gas generated in the kiln furnace passes through the chimney 110 to enter the waste heat recovery section and waste heat recovery is needed, the first smoke discharge regulating valve 113 in the main flue 111 is regulated to be in a closed state, the second smoke discharge regulating valve 114 in the bypass flue 112 is regulated to be in an open state, and at the moment, the flue gas can be continuously discharged outwards from the bypass flue 112 after passing through the heat collector 120. When the flue gas passes through the heat collector 120, heat in the flue gas is collected and conducted by a first circulating medium in the heat collector 120, and is transferred to the heat exchanger 130 through the circulating pipeline 140, and is supplied to heat utilization equipment at a demand end through the heat exchanger 130. The heat collecting side and the heat demand side of the heat exchanger 130 are respectively provided with a first driving member 144 and a second driving member 153, so that the first circulating medium and the second circulating medium are ensured to be in a flowing state, and further continuous collection and conduction of heat are realized. In addition, by controlling the valve opening of the first smoke discharge control valve 113 and the second smoke discharge control valve 114, the flow rate of the smoke in the main flue 111 and the bypass flue 112 can be changed, and the heat collector 120 is protected from overheat due to excessive smoke flowing during the low heat consumption period. The overheat of the heat collector 120 may cause a phase change of the first circulating medium therein due to high temperature, and thus cause abnormal pressure of the heat collector 120, resulting in potential safety hazard. When the flue gas waste heat recovery device 100 needs to be overhauled and maintained, the opening and closing states of the first smoke discharging adjusting valve 113 and the second smoke discharging adjusting valve 114 are changed, so that the operation of the kiln is not influenced in the overhauling and maintenance process of the waste heat recovery device.

In summary, the embodiment provides a flue gas waste heat recovery device 100, by arranging the heat collector 120 at the waste heat recovery section of the chimney 110, primary heat exchange with flue gas can be achieved, then the heat collector 120 is connected with the heat exchanger 130 through the circulation pipeline 140, so that secondary heat exchange between the heat collector 120 and the heat exchanger 130 is achieved, and after heat exchange between the heat exchanger 130, heat supply is achieved by connecting the heat exchanger with heat utilization equipment through the heat exchange pipeline 150. In addition, through the first smoke discharging adjusting valve 113 and the second smoke discharging adjusting valve 114, the smoke flow can be accurately controlled, so that the smoke flow flowing through the heat collector 120 is proper, and the heat collector 120 is prevented from being overheated. Meanwhile, by arranging the bypass pipe 145 and the bypass switch 146, the first circulating medium can be in a flowing state even if the heat exchanger 130 is stopped, the overheat condition of the heat collector 120 is further avoided, the safety of the device is ensured, and the service life of the device is prolonged.

Second embodiment

Referring to fig. 2, the present embodiment provides a flue gas waste heat recovery device 100, whose basic structure and principle and technical effects are the same as those of the first embodiment, and for brevity, reference is made to the corresponding contents of the first embodiment where the description of the embodiment is omitted.

In this embodiment, an air induction component 160 is further disposed at the outlet of the chimney 110 or on the bypass flue 112, and the air induction component 160 is used for balancing the wind pressure in the chimney 110. Preferably, in this embodiment, the air guiding component 160 may be disposed at the outlet of the chimney 110, and the air guiding component 160 may be an air guiding fan, so as to realize the extraction of the flue gas by the air guiding fan, thereby balancing the wind pressure influence on the chimney 110 caused by the arrangement of the bypass flue 112, further preventing the influence on the pressure of the combustion chamber inside the kiln due to the abnormal partial pressure generated in the chimney 110, and ensuring the smooth discharge of the flue gas.

In this embodiment, the first medium inlet pipe 141 and the first medium outlet pipe 142 are both provided with a pressure detector 147 and an automatic pressure reducer (not shown), wherein the pressure detector 147 is used for detecting the pipeline pressure of the circulation pipeline 140, and the automatic pressure reducer may be a pressure release valve or a buffer valve, etc. capable of realizing pressure control. The pressure detector 147 is in a linkage state with the automatic pressure reducer, and when the pressure detector 147 detects that the pressure on the first medium inlet pipe 141 and the first medium outlet pipe 142 is too high to exceed the limit, the pressure can be rapidly released through the automatic pressure reducer, so that the safety of the circulation pipeline 140 is ensured.

The flue gas waste heat recovery device 100 provided in this embodiment, through additionally setting up induced air subassembly 160, can prevent to produce the influence to the pressure of the inside combustion chamber of cellar for storing things stove because of the unusual partial pressure that produces in the chimney 110, guaranteed the smooth emission of flue gas. And additionally, the pressure detector 147 and the automatic pressure reducer are arranged, so that the pressure abnormality in the circulating pipeline 140 of the flue gas waste heat recovery device 100 can be prevented, the use safety of the kiln is affected, and potential safety hazards are caused.

Further, pressure gauges may be provided on the second medium inlet pipe 151 and the second medium outlet pipe 152, so that the safety of the pipeline is ensured.

The foregoing is merely illustrative of the present utility model, and the present utility model is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the scope of the present utility model should be included in the present utility model. Therefore, the protection scope of the present utility model shall be subject to the protection scope of the claims.

Claims (9)

1. A flue gas waste heat recovery device, characterized by comprising a chimney (110), a heat collector (120), a heat exchanger (130), a circulation pipeline (140) and a heat exchange pipeline (150), wherein the chimney (110) is provided with a waste heat recovery section and is used for discharging flue gas, the heat collector (120) is arranged at the waste heat recovery section and is used for realizing primary heat exchange with the flue gas, the heat exchanger (130) is arranged outside the chimney (110) and is connected with the heat collector (120) through the circulation pipeline (140), so that the heat exchanger (130) and the heat collector (120) realize secondary heat exchange, a first circulation medium is filled in the circulation pipeline (140), the first circulation medium is used for transferring heat collected by the heat collector (120) to the heat exchanger (130), the heat exchange pipeline (150) is connected with the heat exchanger (130) and is used for being connected to a heat utilization device, and a second circulation medium is filled in the heat exchange pipeline (150) and is used for transferring the heat collected by the heat exchanger (130) to the heat utilization device;

the waste heat recovery section comprises a main flue (111) and a bypass flue (112), the main flue (111) is used for discharging flue gas outwards, a first smoke discharging regulating valve (113) is arranged on the main flue (111), and the first smoke discharging regulating valve (113) is used for conducting or cutting off the main flue (111); the bypass flue (112) is connected to the main flue (111), and the air inlet end and the air outlet end of the bypass flue (112) are respectively connected to two sides of the first smoke discharge regulating valve (113), a second smoke discharge regulating valve (114) is arranged on the bypass flue (112), the second smoke discharge regulating valve (114) is used for conducting or cutting off the bypass flue (112), and the heat collector (120) is arranged on the bypass flue (112) and is located on the air outlet side of the second smoke discharge regulating valve (114).

2. The flue gas waste heat recovery device according to claim 1, wherein the first flue gas regulating valve (113) has a first opening valve plate for regulating the opening of the first flue gas regulating valve (113), and the second flue gas regulating valve (114) has a second opening valve plate for regulating the opening of the second flue gas regulating valve (114).

3. The flue gas waste heat recovery device according to claim 1, wherein an air guiding assembly (160) is further arranged at the outlet of the chimney (110) or on the bypass flue (112), and the air guiding assembly (160) is used for balancing air pressure in the chimney (110).

4. The flue gas waste heat recovery device according to claim 1, wherein the circulation pipeline (140) comprises a first medium inlet pipe (141) and a first medium outlet pipe (142), two ends of the first medium inlet pipe (141) are respectively connected to the inlet of the heat collector (120) and the outlet of the heat exchanger (130), two ends of the first medium outlet pipe (142) are respectively connected to the outlet of the heat collector (120) and the inlet of the heat exchanger (130), and a circulation switch (143) is further arranged on the first medium inlet pipe (141) and/or the first medium outlet pipe (142).

5. The flue gas waste heat recovery device according to claim 4, wherein a first driving member (144) is provided on the first medium inlet pipe (141) and/or the first medium outlet pipe (142) to circulate the first circulating medium between the heat collector (120) and the heat exchanger (130).

6. The flue gas waste heat recovery device according to claim 5, wherein the circulation pipe (140) further comprises a bypass pipe (145), both ends of the bypass pipe (145) are respectively connected to the first medium inlet pipe (141) and the first medium outlet pipe (142), the first driving member (144) is disposed between the bypass pipe (145) and the heat collector (120), and a bypass switch (146) is disposed on the bypass pipe (145), and the circulation switch (143) is disposed between the bypass pipe and the heat exchanger (130).

7. The flue gas waste heat recovery device according to claim 4, wherein the heat exchange pipeline (150) comprises a second medium inlet pipe (151) and a second medium outlet pipe (152), one end of the second medium inlet pipe (151) is connected with the inlet of the heat exchanger (130), the other end is used for being connected to the outlet of the heat utilization device, one end of the second medium outlet pipe (152) is connected with the outlet of the heat exchanger (130), and the other end is used for being connected to the inlet of the heat utilization device.

8. The flue gas waste heat recovery device according to claim 7, wherein a second driving member (153) is further provided on the second medium inlet pipe (151) and/or the second medium outlet pipe (152) to circulate the second circulating medium between the heat exchanger (130) and the heat consuming apparatus.

9. The flue gas waste heat recovery device according to claim 4, wherein a pressure detector (147) and an automatic pressure reducer are arranged on the first medium inlet pipe (141) and the first medium outlet pipe (142).