A flue gas heat recovery device for a gas-fired boiler

Abstract

This utility model discloses a flue gas heat recovery device for a gas-fired boiler, belonging to the field of flue gas heat recovery technology. It includes a storage tank, with a lower heat exchange tank fixedly connected to its top surface. In this utility model, the high-temperature water after heat exchange is stored in the storage tank, while the high temperature of the flue gas is used to keep the high-temperature water in the storage tank warm. Furthermore, a lower heat exchange tank, a middle heat exchange tank, and an upper heat exchange tank are arranged at the top of the storage tank. Flue gas and water exchange heat in these three tanks respectively. As the flue gas rises, its temperature gradually decreases, resulting in water at different temperatures in the lower, middle, and upper heat exchange tanks. When the water temperature in the upper tank reaches a predetermined value, the water moves down to the next tank for further heating, ensuring efficient heat exchange between the water and the flue gas, thus guaranteeing the quality of heat recovery from the flue gas. This method is highly practical.

Description

Technical Field

[0001] This utility model relates to the field of flue gas heat recovery technology, and more specifically, to a flue gas heat recovery device for a gas-fired boiler. Background Technology

[0002] A gas-fired boiler is a device that uses gas as fuel to heat a working medium through combustion. During combustion, it produces a large amount of high-temperature flue gas containing significant waste heat. Directly releasing this waste heat into the atmosphere not only wastes energy but also pollutes the environment. Flue gas waste heat recovery units are widely used energy-saving devices in industry, primarily used to recover waste heat from the flue gas emitted by boilers, kilns, and other equipment, converting it into usable thermal energy through heat exchange. However, existing recovery units are inconvenient for storing the heated water after heat exchange, and they only use a single heat exchange group. When the heated water reaches a certain high temperature, the heat exchange efficiency between the water and the flue gas decreases, affecting the quality of flue gas heat recovery. Therefore, we propose a flue gas heat recovery device for gas-fired boilers. Utility Model Content

[0003] In view of the problems existing in the prior art, the purpose of this utility model is to provide a flue gas heat recovery device for gas boilers.

[0004] To solve the above problems, the present invention adopts the following technical solution:

[0005] A flue gas heat recovery device for a gas-fired boiler includes a storage tank, a lower heat exchange tank fixedly connected to the top surface of the storage tank, a middle heat exchange tank fixedly connected to the top surface of the lower heat exchange tank, an upper heat exchange tank fixedly connected to the top surface of the middle heat exchange tank, a water filling mechanism on the upper heat exchange tank, and insulation cotton fixedly sleeved on the outside of the storage tank. Heat exchange mechanisms are provided on the storage tank, lower heat exchange tank, middle heat exchange tank, and upper heat exchange tank. A first electrically controlled valve is fixedly installed at the top of the inner cavity of the storage tank, with its tip extending into the inner cavity of the lower heat exchange tank. A second electrically controlled valve is fixedly installed at the top of the inner cavity of the lower heat exchange tank, with its tip extending into the inner cavity of the middle heat exchange tank. A third electrically controlled valve is fixedly installed at the top of the inner cavity of the middle heat exchange tank, with its tip extending into the inner cavity of the upper heat exchange tank.

[0006] In a preferred embodiment of this utility model, the heat exchange mechanism includes an air inlet pipe fixedly sleeved on the outside of the liquid storage tank. The end of the air inlet pipe extends into the inner cavity of the liquid storage tank and is fixedly connected to an insulated gas distribution box. Multiple insulated heat exchange pipes are arranged on the top of the insulated gas distribution box. An insulated gas collection box is fixedly connected to the top of the multiple insulated heat exchange pipes. A first conduit is fixedly connected to the top surface of the insulated gas collection box. The top of the first conduit is fixedly sleeved into the inner cavity of the lower heat exchange tank and fixedly connected to a lower gas distribution box. Multiple lower heat exchange pipes are arranged on the top surface of the lower gas distribution box. A lower gas collection box is fixedly connected to the top of the multiple lower heat exchange pipes. A second conduit is fixedly connected to the top surface of the lower gas collection box. The top of the second conduit is fixedly sleeved into the inner cavity of the middle heat exchange tank and fixedly connected to a middle gas distribution box. The top surface of the middle gas distribution box is provided with multiple middle heat exchange tubes, and the top ends of the multiple middle heat exchange tubes are fixedly connected to a middle gas collection box. The top surface of the middle gas collection box is fixedly connected to a third conduit, and the top end of the third conduit is fixedly sleeved to the inner cavity of the upper heat exchange tank and fixedly connected to the upper heat exchange box. The top surface of the upper heat exchange box is fixedly connected to an exhaust pipe, and the top end of the exhaust pipe is fixedly sleeved to the outside of the upper heat exchange tank. The top surface of the heat-insulated gas distribution box is provided with a first temperature sensor, the top surface of the lower gas distribution box is provided with a second temperature sensor, the top surface of the middle gas distribution box is provided with a third temperature sensor, and the top surface of the upper heat exchange box is provided with a fourth temperature sensor. The bottom surface of the heat-insulated gas distribution box is fixedly connected with multiple support columns, and the bottom end of the support columns is connected to the bottom surface of the inner cavity of the liquid storage tank.

[0007] As a preferred embodiment of this utility model, the water supply mechanism includes a water pump fixedly installed on the top surface of the upper heat exchange tank, the output end of the water pump extending into the inner cavity of the upper heat exchange tank, and the input end of the water pump being fixedly connected to a water supply pipe.

[0008] As a preferred embodiment of this utility model, a first liquid level sensor is provided on the top surface of the inner cavity of the storage tank, a second liquid level sensor is provided on the top surface of the inner cavity of the lower heat exchange tank, a third liquid level sensor is provided on the top surface of the inner cavity of the middle heat exchange tank, and a fourth liquid level sensor is provided on the top surface of the inner cavity of the upper heat exchange tank.

[0009] As a preferred embodiment of this utility model, a control panel is fixedly installed on the outside of the liquid storage tank. The control panel is electrically connected to the water pump, the first solenoid valve, the second solenoid valve, the third solenoid valve, the first liquid level sensor, the second liquid level sensor, the third liquid level sensor, the fourth liquid level sensor, the first temperature sensor, the second temperature sensor, the third temperature sensor, and the fourth temperature sensor.

[0010] As a preferred embodiment of this utility model, a plurality of self-locking casters are fixedly installed on the bottom surface of the liquid storage tank, and a switch valve is fixedly installed on the outer side of the liquid storage tank, with the end of the switch valve extending into the inner cavity of the liquid storage tank.

[0011] Compared with existing technologies, the advantages of this utility model are:

[0012] In this invention, a storage tank is used to store the high-temperature water after heat exchange. Simultaneously, the high temperature of the flue gas is used to insulate the high-temperature water in the storage tank. Furthermore, a lower heat exchange tank, a middle heat exchange tank, and an upper heat exchange tank are installed at the top of the storage tank. Heat exchange between the flue gas and water occurs in these three tanks respectively. As the flue gas rises, its temperature gradually decreases, resulting in water at different temperatures in the lower, middle, and upper heat exchange tanks. When the water temperature in the upper tank reaches a predetermined value, the water is moved down to the next tank for further heating, ensuring efficient heat exchange between the water and the flue gas. This guarantees the quality of heat recovery from the flue gas and demonstrates good practicality. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0014] Figure 2 This is a schematic cross-sectional view of the present invention;

[0015] Figure 3 This is a schematic diagram of the heat exchange tank in this utility model;

[0016] Figure 4 This is a schematic diagram of the heat exchange mechanism of this utility model.

[0017] Explanation of the labels in the diagram:

[0018] 1. Liquid storage tank; 2. Lower heat exchanger tank; 3. Middle heat exchanger tank; 4. Upper heat exchanger tank; 5. Heat exchange mechanism; 6. Insulation cotton; 7. First electric control valve; 8. Second electric control valve; 9. Third electric control valve; 10. Water filling mechanism; 11. Air inlet pipe; 12. Insulated gas distribution box; 13. Insulated heat exchanger tube; 14. Insulated gas collection box; 15. First conduit; 16. Lower gas distribution box; 17. Lower heat exchanger tube; 18. Lower gas collection box; 19. Second conduit; 20. Middle gas distribution box; 21. Middle heat exchanger tube; 22. Central gas collector box; 23. Third conduit; 24. Upper heat exchanger box; 25. Exhaust pipe; 26. First temperature sensor; 27. Second temperature sensor; 28. Third temperature sensor; 29. ​​Fourth temperature sensor; 30. Water pump; 31. Water supply pipe; 32. Support column; 33. First liquid level sensor; 34. Second liquid level sensor; 35. Third liquid level sensor; 36. Fourth liquid level sensor; 37. Self-locking casters; 38. Switch valve; 39. Control panel. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0020] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0022] Example:

[0023] Please see Figure 1-4 A flue gas heat recovery device for a gas-fired boiler includes a storage tank 1, a lower heat exchange tank 2 fixedly connected to the top surface of the storage tank 1, a middle heat exchange tank 3 fixedly connected to the top surface of the lower heat exchange tank 2, an upper heat exchange tank 4 fixedly connected to the top surface of the middle heat exchange tank 3, a water filling mechanism 10 provided on the upper heat exchange tank 4, insulation cotton 6 fixedly sleeved on the outside of the storage tank 1, and heat exchange mechanisms 5 provided on the storage tank 1, the lower heat exchange tank 2, the middle heat exchange tank 3 and the upper heat exchange tank 4. A first electrically controlled valve 7 is fixedly installed at the top of the inner cavity of the storage tank 1, with the top end of the first electrically controlled valve 7 extending into the inner cavity of the lower heat exchange tank 2. A second electrically controlled valve 8 is fixedly installed at the top of the inner cavity of the lower heat exchange tank 2, with the top end of the second electrically controlled valve 8 extending into the inner cavity of the middle heat exchange tank 3. A third electrically controlled valve 9 is fixedly installed at the top of the inner cavity of the middle heat exchange tank 3, with the top end of the third electrically controlled valve 9 extending into the inner cavity of the upper heat exchange tank 4.

[0024] In this embodiment, vent holes can be opened at the top of the liquid storage tank 1, the lower heat exchange tank 2, the middle heat exchange tank 3, and the upper heat exchange tank 4 to ensure that the water in the liquid storage tank 1, the lower heat exchange tank 2, the middle heat exchange tank 3, and the upper heat exchange tank 4 can flow smoothly downwards. This is a conventional operation and will not be described in detail. The internal cavity size of the liquid storage tank 1, the lower heat exchange tank 2, the middle heat exchange tank 3, and the upper heat exchange tank 4 gradually decreases from bottom to top, and ensures that the amount that the lower tank can store is more than twice the amount that the upper tank can store.

[0025] For details, please refer to Figure 1 , Figure 2 and Figure 4 The heat exchange mechanism 5 includes an air inlet pipe 11 fixedly sleeved on the outside of the liquid storage tank 1. The end of the air inlet pipe 11 extends into the inner cavity of the liquid storage tank 1 and is fixedly connected to an insulated gas distribution box 12. Multiple insulated heat exchange pipes 13 are arranged on the top of the insulated heat exchange pipes 13. An insulated gas collection box 14 is fixedly connected to the top of the insulated gas collection box 14. A first conduit 15 is fixedly connected to the top of the first conduit 15, which is fixedly sleeved into the inner cavity of the lower heat exchange tank 2 and is fixedly connected to a lower gas distribution box 16. Multiple lower heat exchange pipes 17 are arranged on the top surface of the lower gas distribution box 16. A lower gas collection box 18 is fixedly connected to the top of the multiple lower heat exchange pipes 17. A second conduit 19 is fixedly connected to the top surface of the lower gas collection box 18. The top of the second conduit 19 is fixedly sleeved into the inner cavity of the middle heat exchange tank 3 and is fixedly connected to a middle gas distribution box 20. The top surface of the heat exchanger is provided with multiple intermediate heat exchange tubes 21. The top ends of the multiple intermediate heat exchange tubes 21 are fixedly connected to intermediate gas collection boxes 22. The top surface of the intermediate gas collection boxes 22 is fixedly connected to a third conduit 23. The top end of the third conduit 23 is fixedly sleeved to the inner cavity of the upper heat exchange tank 4 and fixedly connected to an upper heat exchange box 24. The top surface of the upper heat exchange box 24 is fixedly connected to an exhaust pipe 25. The top end of the exhaust pipe 25 is fixedly sleeved to the outside of the upper heat exchange tank 4. The top surface of the heat-insulated gas distribution box 12 is provided with a first temperature sensor 26. The top surface of the lower gas distribution box 16 is provided with a second temperature sensor 27. The top surface of the intermediate gas distribution box 20 is provided with a third temperature sensor 28. The top surface of the upper heat exchange box 24 is provided with a fourth temperature sensor 29. The bottom surface of the heat-insulated gas distribution box 12 is fixedly connected with multiple support columns 32. The bottom end of the support columns 32 is connected to the bottom surface of the inner cavity of the liquid storage tank 1.

[0026] In this embodiment, the end of the air inlet pipe 11 is connected to the flue gas outlet of the gas boiler so that the heat of the flue gas can be recovered in the device. The heat-insulated gas distribution box 12, heat-insulated heat exchange pipe 13, heat-insulated gas collection box 14, first conduit 15, lower gas distribution box 16, lower heat exchange pipe 17, lower gas collection box 18, second conduit 19, middle gas distribution box 20, middle heat exchange pipe 21, middle gas collection box 22, third conduit 23, and upper heat exchange box 24 are all made of heat transfer materials, such as aluminum alloy and copper, to ensure that the flue gas and water can exchange heat smoothly.

[0027] For details, please refer to Figure 1 The water supply mechanism 10 includes a water pump 30 fixedly installed on the top surface of the upper heat exchange tank 4. The output end of the water pump 30 extends into the inner cavity of the upper heat exchange tank 4, and the input end of the water pump 30 is fixedly connected to a water supply pipe 31.

[0028] In this embodiment, the end of the water supply pipe 31 is connected to an external water source so that water can be added to the inner cavity of the heat exchange tank 4 through the water pump 30 and the water supply pipe 31.

[0029] For details, please refer to Figure 2 A first liquid level sensor 33 is installed on the top surface of the inner cavity of the storage tank 1, a second liquid level sensor 34 is installed on the top surface of the inner cavity of the lower heat exchange tank 2, a third liquid level sensor 35 is installed on the top surface of the inner cavity of the middle heat exchange tank 3, and a fourth liquid level sensor 36 is installed on the top surface of the inner cavity of the upper heat exchange tank 4.

[0030] In this embodiment, the water volume in the inner cavities of the storage tank 1, the lower heat exchange tank 2, the middle heat exchange tank 3, and the upper heat exchange tank 4 is controlled by the first liquid level sensor 33, the second liquid level sensor 34, the third liquid level sensor 35, and the fourth liquid level sensor 36.

[0031] For details, please refer to Figures 1 to 4 A control panel 39 is fixedly installed on the outside of the storage tank 1. The control panel 39 is electrically connected to the water pump 30, the first solenoid valve 7, the second solenoid valve 8, the third solenoid valve 9, the first liquid level sensor 33, the second liquid level sensor 34, the third liquid level sensor 35, the fourth liquid level sensor 36, the first temperature sensor 26, the second temperature sensor 27, the third temperature sensor 28, and the fourth temperature sensor 29.

[0032] In this embodiment, the control panel 39 is used to process the information detected by the first liquid level sensor 33, the second liquid level sensor 34, the third liquid level sensor 35, the fourth liquid level sensor 36, the first temperature sensor 26, the second temperature sensor 27, the third temperature sensor 28, and the fourth temperature sensor 29, so as to control the water pump 30, the first solenoid valve 7, the second solenoid valve 8, and the third solenoid valve 9 through the control panel 39.

[0033] For details, please refer to Figure 1 Multiple self-locking casters 37 are fixedly installed on the bottom surface of the liquid storage tank 1, and a switch valve 38 is fixedly installed on the outside of the liquid storage tank 1, with the end of the switch valve 38 extending into the inner cavity of the liquid storage tank 1.

[0034] In this embodiment, the device is supported by self-locking casters 37, which can also drive the device to move. In addition, the switch valve 38 can release the hot water in the inner cavity of the storage tank 1 for use.

[0035] Working Principle: In operation, the lower heat exchanger 2 and middle heat exchanger 3 are first filled halfway with water, filling the inner cavity of the upper heat exchanger 4 completely. The temperatures of the second temperature sensor 27, third temperature sensor 28, and fourth temperature sensor 29 are set using the control panel 39. The temperatures set by the fourth temperature sensor 29, third temperature sensor 28, and second temperature sensor 27 gradually increase. Then, the high-temperature flue gas is introduced into the inner cavity of the insulated gas distribution box 12 through the inlet pipe 11. The flue gas is then introduced into the inner cavity of the lower gas distribution box 16 through the insulated gas distribution box 12, insulated heat exchange pipe 13, insulated gas collection box 14, and first conduit 15. This allows the flue gas to flow within the lower gas distribution box 16, lower heat exchange pipe 17, and lower gas collection box 18. Simultaneously, the lower gas distribution box 16… The flue gas in the lower heat exchanger tube 17 and lower gas collecting box 18 exchanges heat with the water in the inner cavity of the lower heat exchange tank 2. At this time, the temperature of the flue gas is relatively high, so the water in the inner cavity of the lower heat exchange tank 2 is heated quickly. When the second temperature sensor 27 detects that the temperature in the inner cavity of the lower heat exchange tank 2 has reached the set value, the control panel 39 controls the first solenoid valve 7 to open for a certain period of time, so that the high-temperature water in the inner cavity of the lower heat exchange tank 2 enters the inner cavity of the storage tank 1 for storage. At the same time, the flue gas temperature in the insulated gas distribution box 12, insulated heat exchanger tube 13 and insulated gas collecting box 14 is used to keep the high-temperature water in the inner cavity of the storage tank 1 warm. Then, the flue gas after one heat exchange is introduced into the inner cavity of the middle gas distribution box 20 through the second conduit 19, so that the flue gas circulates in the middle gas distribution box 20, the middle heat exchanger tube 21 and the middle gas collecting box 20. The flue gas flows through the gas collection box 22, allowing heat exchange between the flue gas in the middle gas distribution box 20, the middle heat exchange tube 21, and the middle gas collection box 22, and the water inside the middle heat exchange tank 3, thereby heating the water inside the middle heat exchange tank 3. When the third temperature sensor 28 detects that the water temperature inside the middle heat exchange tank 3 has reached the set value, the control panel 39 controls the second solenoid valve 8 to open for a certain period of time, allowing the water inside the middle heat exchange tank 3 to enter the inner cavity of the lower heat exchange tank 2, thus continuing to heat the water in the lower heat exchange tank 2. Then, the flue gas in the middle gas collection box 22 is introduced into the inner cavity of the upper heat exchange box 24 through the third conduit 23, where heat exchange occurs between the flue gas in the upper heat exchange box 24 and the water inside the upper heat exchange tank 4, thereby heating the water inside the upper heat exchange tank 4. This process is repeated three times. The temperature of the hot flue gas has already dropped. The flue gas is then discharged from the exhaust pipe 25 from the upper heat exchanger box 24 for further processing. When the fourth temperature sensor 29 detects that the temperature inside the upper heat exchanger tank 4 has reached a predetermined value, the control panel 39 controls the third solenoid valve 9 to open for a certain period, allowing water from the upper heat exchanger tank 4 to be introduced into the middle heat exchanger tank 3 so that the water can continue to be heated in the middle heat exchanger tank 3. Finally, when the third solenoid valve 9 closes, the control panel 39 controls the water pump 30 to start. The water pump 30 and the water supply pipe 31 pump external water into the upper heat exchanger tank 4. When the fourth liquid level sensor 36 detects water, the surface of the heat exchanger tank 4 appears to be full of water. At this point, the control panel 39 shuts off the water pump 30.Continue to use the flue gas inside the upper heat exchange box 24 to heat the water in the upper heat exchange tank 4.

[0036] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model based on the technical solution and its improved concept should be covered within the protection scope of the present utility model.

Claims

1. A flue gas heat recovery device for a gas-fired boiler, characterized in that: The system includes a storage tank (1), a lower heat exchange tank (2) fixedly connected to the top surface of the storage tank (1), a middle heat exchange tank (3) fixedly connected to the top surface of the lower heat exchange tank (2), an upper heat exchange tank (4) fixedly connected to the top surface of the middle heat exchange tank (3), a water filling mechanism (10) provided on the upper heat exchange tank (4), and insulation cotton (6) fixedly sleeved on the outside of the storage tank (1). Heat exchange mechanisms are provided on the storage tank (1), lower heat exchange tank (2), middle heat exchange tank (3), and upper heat exchange tank (4). (5) A first electrically controlled valve (7) is fixedly installed on the top of the inner cavity of the liquid storage tank (1). The top of the first electrically controlled valve (7) extends to the inner cavity of the lower heat exchange tank (2). A second electrically controlled valve (8) is fixedly installed on the top of the inner cavity of the lower heat exchange tank (2). The top of the second electrically controlled valve (8) extends to the inner cavity of the middle heat exchange tank (3). A third electrically controlled valve (9) is fixedly installed on the top of the inner cavity of the middle heat exchange tank (3). The top of the third electrically controlled valve (9) extends to the inner cavity of the upper heat exchange tank (4).

2. A heat recovery device for flue gases of a gas boiler according to claim 1, characterized in that: The heat exchange mechanism (5) includes an air inlet pipe (11) fixedly sleeved on the outside of the liquid storage tank (1). The end of the air inlet pipe (11) extends into the inner cavity of the liquid storage tank (1) and is fixedly connected to an insulated gas distribution box (12). The top of the insulated gas distribution box (12) is provided with multiple insulated heat exchange pipes (13). The top ends of the multiple insulated heat exchange pipes (13) are fixedly connected to an insulated gas collection box (14). The top surface of the insulated gas collection box (14) is fixedly connected to a first conduit (15). The top end of the lower heat exchanger (2) is fixedly sleeved into the inner cavity of the lower heat exchanger (2) and fixedly connected to a lower gas distribution box (16). Multiple lower heat exchange tubes (17) are provided on the top surface of the lower gas distribution box (16). A lower gas collection box (18) is fixedly connected to the top end of the multiple lower heat exchange tubes (17). A second conduit (19) is fixedly connected to the top surface of the lower gas collection box (18). The top end of the second conduit (19) is fixedly sleeved into the inner cavity of the middle heat exchanger (3) and fixedly connected to a middle gas distribution box (20). The top surface of the upper heat exchanger is provided with multiple intermediate heat exchange tubes (21), and the top ends of the multiple intermediate heat exchange tubes (21) are fixedly connected to intermediate gas collection boxes (22). The top surface of the intermediate gas collection boxes (22) is fixedly connected to a third conduit (23). The top end of the third conduit (23) is fixedly sleeved to the inner cavity of the upper heat exchanger (4) and fixedly connected to an upper heat exchanger box (24). The top surface of the upper heat exchanger box (24) is fixedly connected to an exhaust pipe (25), and the top end of the exhaust pipe (25) is fixedly sleeved to the outside of the upper heat exchanger (4). The top surface of the heat-insulating gas distribution box (12) is provided with a first temperature sensor (26), the top surface of the lower gas distribution box (16) is provided with a second temperature sensor (27), the top surface of the middle gas distribution box (20) is provided with a third temperature sensor (28), the top surface of the upper heat exchange box (24) is provided with a fourth temperature sensor (29), and the bottom surface of the heat-insulating gas distribution box (12) is fixedly connected with multiple support columns (32), the bottom end of the support columns (32) is connected to the bottom surface of the inner cavity of the liquid storage tank (1).

3. A heat recovery device for flue gases of a gas boiler according to claim 2, characterized in that: The water supply mechanism (10) includes a water pump (30) fixedly installed on the top surface of the upper heat exchange tank (4), the output end of the water pump (30) extends into the inner cavity of the upper heat exchange tank (4), and the input end of the water pump (30) is fixedly connected to a water supply pipe (31).

4. A heat recovery device for the fumes of a gas boiler according to claim 3, characterized in that: A first liquid level sensor (33) is provided on the top surface of the inner cavity of the storage tank (1), a second liquid level sensor (34) is provided on the top surface of the inner cavity of the lower heat exchange tank (2), a third liquid level sensor (35) is provided on the top surface of the inner cavity of the middle heat exchange tank (3), and a fourth liquid level sensor (36) is provided on the top surface of the inner cavity of the upper heat exchange tank (4).

5. A heat recovery device for the fumes of a gas boiler according to claim 4, characterized in that: A control panel (39) is fixedly installed on the outside of the liquid storage tank (1). The control panel (39) is electrically connected to the water pump (30), the first electric control valve (7), the second electric control valve (8), the third electric control valve (9), the first liquid level sensor (33), the second liquid level sensor (34), the third liquid level sensor (35), the fourth liquid level sensor (36), the first temperature sensor (26), the second temperature sensor (27), the third temperature sensor (28), and the fourth temperature sensor (29).

6. A heat recovery device for flue gases of a gas boiler according to claim 1, characterized in that: The bottom surface of the liquid storage tank (1) is fixedly equipped with multiple self-locking casters (37), and the outside of the liquid storage tank (1) is fixedly equipped with a switch valve (38), the end of which extends into the inner cavity of the liquid storage tank (1).

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