Waste heat recovery device and boiler

Abstract

The utility model relates to the technical field of power station boilers, in particular to a waste heat recovery device and a boiler. The waste heat recovery device comprises an air pre-heater and an air heater, the air pre-heater comprises a first detection part, a second detection part and a third detection part, the first detection part is used for detecting the dew point temperature of flue gas at a flue gas inlet, and the second detection part can detect the first pressure value of the flue gas at the flue gas inlet and the second pressure value of the flue gas at a flue gas outlet; the third detection piece is used for detecting the temperature of air introduced into the air duct mechanism; multiple working modes are preset in the air heater, the air heater is in communication connection with the first detection piece, the second detection piece and the third detection piece, different working modes can be selected to heat air introduced into the air duct mechanism, and condensation corrosion and dust deposition blockage of the air preheater are avoided. By applying the waste heat recovery device to the boiler, equipment damage and maintenance cost caused by moisture condensation can be reduced, and the operation efficiency and safety of the boiler are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of power station boilers, in particular to a waste heat recovery device and a boiler. Background Art

[0002] An air preheater is a waste heat recovery device, also known as an air preheater. It is widely used in power plant boilers. It uses the heat of the flue gas discharged by the boiler to preheat the air entering the boiler for combustion, thereby improving the heat exchange performance of the boiler and reducing energy consumption.

[0003] During the use of existing waste heat recovery devices, due to changes in coal type and ambient wind temperature, the wall temperature at the flue gas outlet is easily reduced to the flue gas acid dew point temperature, which is easy to condense liquid sulfuric acid. Sulfuric acid not only corrodes metals, but also adheres to dust particles in the flue gas, causing them to be deposited in the heat storage elements and the flue gas duct mechanism, causing dust accumulation and corrosion on the walls of the flue gas duct mechanism and the heat storage elements, which not only reduces the thermal efficiency of the boiler, but may also cause equipment damage and safety problems.

[0004] Therefore, there is an urgent need for a waste heat recovery device and a boiler to solve the above problems. Utility Model Content

[0005] The purpose of the utility model is to provide a waste heat recovery device and a boiler to solve the problems of condensation corrosion and ash accumulation blockage of the air preheater caused by changes in coal type and ambient air temperature, improve the operating efficiency and safety of the boiler, and reduce equipment damage and maintenance costs caused by condensation.

[0006] To achieve the above objectives, the following technical solutions are provided:

[0007] Waste heat recovery device, including:

[0008] An air preheater, comprising a flue gas duct mechanism, an air duct mechanism, a first detection member, a second detection member, and a third detection member, wherein the flue gas duct mechanism has a flue gas inlet and a flue gas outlet, the first detection member is configured to detect the dew point temperature of the flue gas at the flue gas inlet, the second detection member is capable of detecting a first pressure value of the flue gas at the flue gas inlet and a second pressure value of the flue gas at the flue gas outlet, and the third detection member is configured to detect the temperature of the air passing into the air duct mechanism;

[0009] A heater configured to heat the air entering the air duct mechanism, the heater being preset with a plurality of different operating modes, the heater being communicatively connected to the first detection member, the second detection member, and the third detection member, and capable of selecting different operating modes to heat the air entering the air duct mechanism. As an optional solution, the air duct mechanism includes:

[0010] The connecting branch is used to connect the air inlet and the air outlet to transmit the hot air discharged from the air outlet to the air inlet.

[0011] As an optional solution, the air duct mechanism further includes:

[0012] The valve is arranged on the connecting branch.

[0013] As an optional solution, the air duct mechanism further includes:

[0014] The fourth detection component is configured to detect the temperature of the flue gas at the flue gas outlet.

[0015] As an optional solution, the waste heat recovery device further includes a control mechanism, which is electrically connected to the air preheater and the air heater respectively.

[0016] As an optional solution, the air heater includes:

[0017] Drive mechanism;

[0018] The heating mechanism is arranged at the output end of the driving mechanism, and the driving mechanism can drive the heating mechanism to rotate so as to switch the heating mechanism between an on state and a off state.

[0019] As an optional solution, the heating mechanism includes:

[0020] inner shell;

[0021] a water collecting tank, arranged on the inner shell;

[0022] At least two tube bundles are provided with the water collecting tank at both ends of the tube bundle along the axial direction, and at least two tube bundles are arranged at intervals along the length direction of the water collecting tank.

[0023] As an optional solution, the air heater further includes a second driving member, which is used to drive the heat source to move from one water collecting tank to another water collecting tank via the tube bundle.

[0024] As an optional solution, the heating mechanism further includes:

[0025] A support member is provided on the inner shell, and at least two of the tube bundles are respectively passed through the support member.

[0026] A boiler comprising the above-mentioned waste heat recovery device.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] The waste heat recovery device provided by the utility model adjusts the working mode of the air preheater according to the data detected by the first detection component, the second detection component and the third detection component, thereby ensuring that the temperature of the flue gas at the flue gas outlet is reduced to the lowest while condensation does not occur in the air preheater, and the flue gas exhaust temperature is reduced to the maximum extent to recover the waste heat of the flue gas; the air preheater heats the air entering into the air inlet, so that the wall temperature of the air preheater is increased, and the problems of condensation corrosion and dust accumulation blockage of the air preheater caused by changes in coal type and ambient wind temperature are solved.

[0029] The boiler provided by the utility model reduces equipment damage and maintenance costs caused by condensation and improves the operating efficiency and safety of the boiler by applying the above-mentioned waste heat recovery device. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0031] Figure 1 A simplified structural diagram of the waste heat recovery device provided in an embodiment of the utility model;

[0032] Figure 2 A schematic structural diagram of an air heater provided in an embodiment of the present utility model;

[0033] Figure 3 When the heater is off Figure 2 Middle AA view;

[0034] Figure 4 When the heater is on Figure 2 Center AA view.

[0035] Reference numerals:

[0036] 100. Waste heat recovery device;

[0037] 10. Air preheater; 11. Heat storage element; 12. Flue gas duct mechanism; 121. Flue gas inlet; 122. Flue gas outlet; 13. Air duct mechanism; 131. Air inlet; 132. Air outlet; 133. Connecting branch; 134. Valve; 14. First detection element; 15. Second detection element; 16. Fourth detection element; 17. Third detection element;

[0038] 20. Heater; 21. Outer shell; 22. Driving mechanism; 221. First driving member; 222. Transmission member; 23. Heating mechanism; 231. Inner shell; 232. Water collecting tank; 233. Tube bundle; 234. Pipe assembly; 2341. Support tube; 2342. Hose; 235. Support member; 24. Second driving member; 25. Heat source inlet; 26. Water outlet; 27. Manual start / stop mechanism;

[0039] 30. Control mechanism. DETAILED DESCRIPTION

[0040] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0041] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0042] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0043] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0044] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0045] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0046] This embodiment provides a boiler for providing a specified quantity and quality of steam to a steam turbine to drive the steam turbine to rotate and realize thermal power generation.

[0047] The boiler includes a furnace body, in which the combustible material burns to produce flue gas, which contains heat. In order to improve boiler efficiency and achieve energy conservation and emission reduction, it is usually necessary to recover the heat in the flue gas. Therefore, the boiler provided in this embodiment also includes a waste heat recovery device 100. Figure 1As shown, the waste heat recovery device 100 includes an air preheater 10, which includes a flue gas duct mechanism 12, an air duct mechanism 13 and a heat storage element 11. The flue gas duct mechanism 12 has a flue gas inlet 121 and a flue gas outlet 122, the air duct mechanism 13 has an air inlet 131 and an air outlet 132, and the heat storage element 11 is arranged inside the flue gas duct mechanism 12 and the air duct mechanism 13 and can rotate relative to the flue gas duct mechanism 12 and the air duct mechanism 13. When the air preheater 10 is in operation, high-temperature flue gas enters the flue gas duct mechanism 12 from the flue gas inlet 121 along the vertical direction from top to bottom from the flue gas at the rear of the furnace body, passes through the heat storage element 11, transfers heat to the heat storage element 11, and is discharged from the flue gas outlet 122. Air enters the air preheater 10 from the air inlet 131 along the vertical direction from bottom to top. The area of ​​the heat storage element 11 heated by the high-temperature flue gas rotates to the air duct mechanism 13. The heat storage element 11 transfers heat to the air coming in from the air inlet 131. The heated air is transmitted back to the furnace body through the air outlet 132, thereby increasing the temperature of the air required for combustion, thereby improving the efficiency of the boiler.

[0048] During the use of the existing waste heat recovery device 100, due to changes in coal type and ambient wind temperature, the wall temperature at the flue gas outlet 122 is easily reduced to the flue gas acid dew point temperature, and liquid sulfuric acid is easily condensed. Sulfuric acid not only corrodes metals, but also adheres to dust particles in the flue gas, causing them to be deposited in the heat storage element 11 and the flue gas duct mechanism 12, causing dust accumulation and corrosion on the wall of the flue gas duct mechanism 12 and the heat storage element 11, which not only reduces the thermal efficiency of the boiler, but may also cause equipment damage and safety problems.

[0049] In order to solve the above problems, the waste heat recovery device 100 provided in this embodiment also includes a heater 20, which is arranged inside the air duct and is used to heat the air introduced into the air duct mechanism 13 from the air inlet 131. The air preheater 10 includes a first detection component 14, a second detection component 15 and a third detection component 17. The first detection component 14 is configured to detect the dew point temperature of the flue gas at the flue gas inlet 121. The flue gas inlet 121 and the flue gas outlet 122 are both provided with a second detection component 15. The second detection component 15 can detect the first pressure value of the flue gas at the flue gas inlet 121 and the second pressure value of the flue gas at the flue gas outlet 122. The third detection component 17 is used to detect the temperature of the air introduced into the air duct mechanism 13. The heater 20 is preset with multiple different working modes. The heater 20 is communicatively connected with the first detection component 14, the second detection component 15 and the third detection component 17, and can select different working modes to heat the air introduced into the air duct mechanism 13. By adjusting the operating mode of the air preheater 10 based on the data detected by the first detection element 14, the second detection element 15, and the third detection element 17, the air preheater 10 is ensured to have the lowest temperature of the flue gas at the flue gas outlet 122 while preventing condensation from occurring in the air preheater 10. This also minimizes the flue gas exhaust temperature and recovers the flue gas waste heat. The air preheater 10 heats the air entering the air inlet 131, raising the wall temperature of the air preheater 10. This solves the problems of condensation corrosion and ash accumulation in the air preheater 10 caused by changes in coal type and ambient air temperature, improves the operating efficiency and safety of the boiler, and reduces equipment damage and maintenance costs caused by condensation. In addition, during the cold start of the boiler, the air heater 20 can increase the ignition air temperature, improve the initial combustion conditions, save startup oil, and reduce the possibility of unburned oil smoke and oil scale accumulating at the rear of the furnace body and causing secondary combustion.

[0050] Optionally, there are two second detection components 15 , one of which is located at the smoke inlet 121 to detect the first pressure value of the smoke at the smoke inlet 121 , and the other second detection component 15 is located at the smoke outlet 122 to detect the second pressure value of the smoke at the smoke outlet 122 .

[0051] When the third detection component 17 detects that the temperature of the air at the air inlet 131 is less than or equal to a preset value, the heater 20 starts to heat the air entering from the air inlet 131. The second detection component 15 can detect the first pressure value of the flue gas at the flue gas inlet 121 and the second pressure value of the flue gas at the flue gas outlet 122. When the difference between the first pressure value and the second pressure value is greater than the preset pressure difference, the operating power of the heater 20 increases to improve the heating effect of the air until the temperature detected by the third detection component 17 is greater than the dew point temperature detected by the first detection component 14 or when the third detection component 17 detects that the temperature of the air at the air inlet 131 is greater than the preset value, the heater 20 stops working, minimizing the exhaust temperature of the flue gas and recovering the waste heat of the flue gas. Among them, the first detection component 14 can be a dew point transmitter. The second detection component 15 can be a pressure sensor. The third detection component 17 is a temperature sensor.

[0052] It is understandable that the various operating modes of the heater 20 may be on, off, constant power operation, or variable power operation.

[0053] Optionally, the waste heat recovery device 100 also includes a control mechanism 30, which is electrically connected to the air preheater 10 and the air heater 20 respectively to coordinate and control the air preheater 10 and the air heater 20 to cooperate with each other, thereby realizing automated and intelligent management of the waste heat recovery device 100.

[0054] Optionally, the air duct mechanism 13 also includes a connecting branch 133, which is used to connect the air inlet 131 and the air outlet 132 to transmit the hot air discharged from the air outlet 132 to the air inlet 131. When the heater 20 operates at maximum power and still cannot make the temperature of the air entering the air inlet 131 reach a preset condition, the heated air from the air outlet 132 is transmitted to the air inlet 131 through the connecting branch 133 to increase the temperature of the air entering the air inlet 131.

[0055] Optionally, the air duct mechanism 13 further includes a valve 134, which is disposed on the connecting branch 133 and is used to control the opening and closing of the connecting branch 133 and the size of the passage. The valve 134 may be a bypass valve or a solenoid valve, etc. The valve 134 is communicatively connected to the control mechanism 30 to enable the control mechanism 30 to automatically control the opening and closing of the valve 134 and the size of the passage of the valve 134.

[0056] Optionally, the smoke duct includes a fourth detection member 16, which is disposed at the smoke outlet 122. The fourth detection member 16 is configured to detect the temperature of the smoke at the smoke outlet 122, and is used to monitor the temperature of the smoke at the smoke outlet 122 in real time. The fourth detection member 16 may be a temperature sensor.

[0057] Optionally, the air duct mechanism 13 further includes a third detection member 17, which is disposed at the air inlet 131 and is configured to detect the temperature of the air introduced through the air inlet 131. The control mechanism 30 can switch the heater 20 to different operating states based on the temperature of the air introduced into the air duct mechanism 13 detected by the third detection member 17. The third detection member 17 may be a temperature sensor.

[0058] Combine Figures 1-4 The structure of the heater 20 is described as follows. Figures 1-4 As shown, the heater 20 includes a driving mechanism 22 and a heating mechanism 23. The heating mechanism 23 is provided at the output end of the driving mechanism 22. The driving mechanism 22 can drive the heating mechanism 23 to rotate so as to switch the heating mechanism 23 between an on state and an off state.

[0059] Optionally, the heater 20 includes an outer shell 21, a heating mechanism 23 is arranged inside the outer shell 21 and is rotatably connected to the outer shell 21, the number of the heating mechanisms 23 is at least two, and at least two heating mechanisms 23 are arranged at intervals along the length direction of the inner shell 231 to adapt to different sizes of the air duct mechanisms 13 and improve the heating effect on the air.

[0060] Specifically, the drive mechanism 22 includes a first drive member 221 and a transmission member 222. The transmission member 222 is arranged at the output end of the first drive member 221. The heating mechanism 23 is connected to the transmission member 222. The first drive member 221 drives the transmission member 222 to move, thereby driving the heating mechanism 23 to rotate. Among them, the transmission member 222 can be a worm gear structure. The first drive member 221 drives the turbine to rotate, thereby driving the worm to move. The worm is provided with multiple racks. Each heating mechanism 23 is provided with a gear. The gear engages with the corresponding rack, thereby driving at least two heating mechanisms 23 to rotate simultaneously. Among them, the first drive member 221 can be a motor. In other embodiments, each heating mechanism 23 is provided with a corresponding rotation drive structure, and the rotation drive structure drives the corresponding heating mechanism 23 to rotate.

[0061] Furthermore, the heater 20 also includes a manual start-stop part 27, which is provided with a gear. The gear on the manual start-stop part 27 is engaged with the rack on the worm. Rotating the manual start-stop part 27 drives the worm to move, thereby driving at least two heating mechanisms 23 to rotate simultaneously.

[0062] Specifically, the heating mechanism 23 includes an inner housing 231, a water collection tank 232, and at least two tube bundles 233. The inner housing 231 is rotatably connected to the outer housing 21. The water collection tank 232 is mounted on the inner housing 231. The tube bundles 233 communicate with the water collection tank 232 and are each provided with a water collection tank 232 at both ends along the inner housing 231's axis. The at least two tube bundles 233 are spaced apart along the length of the water collection tank 232. A heat source is disposed within at least one of the water collection tanks 232. The heat source can be moved into the at least two tube bundles 233 to increase the contact area with the air and thereby enhance the heating effect on the air. The heat source can be hot water or high-temperature steam.

[0063] Furthermore, the air heater 20 includes a second drive member 24 for driving the heat source from one water collection tank 232 through the tube bundle 233 to the other water collection tank 232 to achieve continuous heating of the air. The second drive member 24 can be a variable frequency pump that drives the heat source through the heat source inlet 25 into one of the water collection tanks 232. The heat source then passes through at least two tube bundles 233, exchanges heat with the hot air, and enters the other water collection tank 232 before being discharged through the water outlet 26.

[0064] The variable frequency pump can operate at a specific power or at a variable power, enabling the heater 20 to operate in both fixed and variable power modes. The control mechanism 30 can control the variable frequency pump to be turned on or off, operated at a specific power, or operated at a variable power based on data detected by the first detection member 14, the second detection member 15, the third detection member 17, and the fourth detection member 16. It should be noted that the control mechanism 30 is conventional technology, and any control mechanism 30 capable of achieving the aforementioned functions can be used in this embodiment.

[0065] Optionally, the heating mechanism 23 also includes two pipe assemblies 234, which are connected to the corresponding water collecting tanks 232. After the heat source enters the heat source inlet 25, it enters the water collecting tank 232 connected to the pipe assembly 234 through one of the pipe assemblies 234, passes through the tube bundle 233, enters the other water collecting tank 232, and is connected to the water outlet through the pipe assembly 234 connected to the water collecting tank 232.

[0066] Specifically, the pipe assembly 234 includes a support pipe 2341 and a hose 2342. The support pipe 2341 is connected to the water collecting tank 232 and is rotatably connected to the outer shell 21. The hose 2342 is arranged in the support pipe 2341 and is connected to the water collecting tank 232. The support pipe 2341 has a protective effect on the hose 2342 to prevent the hose 2342 from twisting when the heating mechanism 23 rotates and affecting the delivery of the heat source.

[0067] Optionally, the heating mechanism 23 further includes a support member 235 disposed on the inner housing 231. The at least two tube bundles 233 are respectively disposed through the support member 235. The support member 235 supports the tube bundles 233 to prevent deformation of the tube bundles 233 during use. Specifically, the support member 235 is a plate-like structure having at least two through-holes formed therein. The tube bundles 233 can pass through the corresponding through-holes and be supported on the support member 235.

[0068] like Figure 3 As shown, when the temperature of the air inlet 131 detected by the third detection member 17 is greater than the preset value, the air preheater 10 has no condensation corrosion phenomenon, and the heater 20 does not need to work at this time. The first driving member 221 drives the heating mechanism 23 to rotate parallel to the air flow direction to reduce wind resistance. Figure 4 As shown, when the temperature detected by the third detection member 17 is less than or equal to the dew point temperature detected by the first detection member 14 or when the third detection member 17 detects that the temperature of the air at the air inlet 131 is less than or equal to the preset value, the first driving member 221 drives the heating mechanism 23 to rotate to a direction perpendicular to the air flow, and the second driving member 24 drives the heat source to pass through the heat source inlet 25, one of the hoses 2342, one of the water collecting tanks 232, the tube bundle 233, another water collecting tank 232, and another hose 2342 in sequence and then be discharged from the water outlet 26 to complete the heating of the air.

[0069] For ease of understanding, combined Figures 1-4 The working process of the waste heat recovery device 100 is described below:

[0070] 1) When the temperature of the air inlet 131 detected by the third detection member 17 is greater than a preset value, the heater 20 does not need to operate;

[0071] 2) When the temperature detected by the third detection member 17 is less than or equal to the dew point temperature detected by the first detection member 14, or when the temperature of the air at the air inlet 131 detected by the third detection member 17 is less than or equal to a preset value, the first driving member 221 drives the heating mechanism 23 to rotate perpendicular to the air flow direction, and the second driving member 24 drives the heat source into the heating mechanism 23, thereby heating the air entering through the air inlet 131;

[0072] 3) When the difference between the first pressure value and the second pressure value detected by the second detection member 15 is greater than the preset pressure difference, the control mechanism 30 controls the operating power of the second driving member 24 to increase, automatically adjusting the supply of the heat source entering the heating mechanism 23, thereby controlling the temperature of the air entering the air inlet 131;

[0073] 4) When the power of the second driving member 24 increases to the maximum and the difference between the first pressure value and the second pressure value is still greater than the preset pressure difference, the valve 134 is opened, and the heated air passes through the air outlet 132 and the connecting branch 133 and enters the air inlet 131, thereby cooperating with the heater 20 to heat the air. The control mechanism 30 controls the opening and opening and closing of the valve 134 according to the size of the pressure difference, and at the same time controls the working mode of the heater 20 until the temperature detected by the third detection member 17 is greater than the temperature detected by the first detection member 14, and the heater 20 stops working.

[0074] Note that throughout this specification, references to terms such as "some embodiments" and "other embodiments" indicate that the specific features, structures, materials, or characteristics described in conjunction with those embodiments or examples are included in at least one embodiment or example of the present invention. Throughout this specification, the schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be incorporated in any suitable manner in any one or more embodiments or examples.

[0075] The above are merely preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will appreciate that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions are readily apparent to those skilled in the art without departing from the scope of the present invention. Therefore, while the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include other equivalent embodiments without departing from the spirit of the present invention. The scope of the present invention is determined by the appended claims.

Claims

1. Waste heat recovery device, characterized in that: include: An air preheater (10) comprises a flue gas duct mechanism (12), an air duct mechanism (13), a first detection member (14), a second detection member (15) and a third detection member (17); the flue gas duct mechanism (12) has a flue gas inlet (121) and a flue gas outlet (122); the first detection member (14) is configured to detect the dew point temperature of the flue gas at the flue gas inlet (121); the second detection member (15) is capable of detecting a first pressure value of the flue gas at the flue gas inlet (121) and a second pressure value of the flue gas at the flue gas outlet (122); and the third detection member (17) is configured to detect the temperature of the air passing into the air duct mechanism (13); A heater (20), the heater (20) being configured to heat the air entering the air duct mechanism (13), the heater (20) being preset with a plurality of different working modes, the heater (20) being communicatively connected with the first detection member (14), the second detection member (15) and the third detection member (17), and being capable of selecting different working modes to heat the air entering the air duct mechanism (13).

2. The waste heat recovery device according to claim 1, characterized in that: The air duct mechanism (13) comprises: A connecting branch (133), wherein the air duct mechanism (13) has an air inlet (131) and an air outlet (132), and the connecting branch (133) is used to connect the air inlet (131) and the air outlet (132) so as to transmit the hot air discharged from the air outlet (132) to the air inlet (131).

3. The waste heat recovery device according to claim 2, characterized in that: The air duct mechanism (13) further comprises: A valve (134) is provided on the connecting branch (133).

4. The waste heat recovery device according to claim 1, characterized in that: The air duct mechanism (13) further comprises: The fourth detection element (16) is configured to detect the temperature of the flue gas at the flue gas outlet (122).

5. The waste heat recovery device according to any one of claims 1 to 4, characterized in that: The waste heat recovery device further comprises a control mechanism (30), and the control mechanism (30) is electrically connected to the air preheater (10) and the air heater (20) respectively.

6. The waste heat recovery device according to any one of claims 1 to 4, characterized in that: The air heater (20) comprises: a driving mechanism (22); The heating mechanism (23) is arranged at the output end of the driving mechanism (22), and the driving mechanism (22) can drive the heating mechanism (23) to rotate so as to switch the heating mechanism (23) between an on state and a off state.

7. The waste heat recovery device according to claim 6, characterized in that: The heating mechanism (23) comprises: Inner housing (231); A water collecting tank (232) is provided on the inner shell (231); At least two tube bundles (233) are provided, and the water collecting box (232) is provided at both ends of the tube bundle (233) along the axial direction. At least two of the tube bundles (233) are arranged at intervals along the length direction of the water collecting box (232).

8. The waste heat recovery device according to claim 7, characterized in that: The air heater (20) further comprises a second driving member (24), wherein the second driving member (24) is used to drive the heat source to move from one water collecting tank (232) to another water collecting tank (232) via the tube bundle (233).

9. The waste heat recovery device according to claim 7, characterized in that: The heating mechanism (23) further comprises: A support member (235) is provided on the inner shell (231), and at least two tube bundles (233) are respectively passed through the support member (235).

10. A boiler, characterized in that It comprises the waste heat recovery device as described in any one of claims 1 to 9.

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