A combustion heat exchange device and a dual-purpose furnace and their control method

Abstract

This invention discloses a combustion heat exchange device, comprising an outer shell (11), an inner shell (12), a gas supply pipe (15), and a flue gas pipe (16). The gas supply pipe (15) has a gas supply channel (151) inside, and a filter (18) is provided within the gas supply channel (151). The filter (18) includes a filter cylinder (181) with filter holes (1811); a baffle (182) covering the port of the filter cylinder (181) facing the inlet of the gas supply channel (151); and an ash collection box (183) with an annular ash collection groove (1831). The inner ring wall is connected to the end edge of the filter cylinder (181) facing the outlet of the gas supply channel (151), and the outer ring wall is tightly attached to the peripheral wall of the gas supply channel (151). This invention also discloses a control method for the above-mentioned combustion heat exchange device and a dual-purpose furnace using the above-mentioned combustion heat exchange device.

Description

Technical Field

[0001] This invention relates to the field of heating equipment technology, specifically to a combustion heat exchange device and a dual-purpose furnace and their control method. Background Technology

[0002] Currently, some residential buildings are equipped with underfloor heating or other hydrothermal heating systems. In these buildings, in addition to domestic water supply, an extra water supply is needed to power the corresponding hydrothermal heating equipment. Therefore, ordinary gas water heaters cannot simultaneously supply hot water for domestic use and heating water for the hydrothermal equipment. A dual-purpose boiler is required to supply both hot water for domestic use and heating water for the equipment.

[0003] In existing dual-purpose boilers, a three-way valve is used to switch between internal and external circulation: In heating mode, the boiler switches to external circulation, and the heat exchange pipes are connected to the heating pipes. Under the action of the circulation pump, the water in the heat exchange pipes is heated by the combustion heat exchange device and then discharged into the heating pipes. Hot water flows through each room through the external circulation, thus achieving heating. In domestic hot water mode, the boiler switches to internal circulation, and the heat exchange pipes themselves form a circulation loop. Under the action of the circulation pump, hot water exchanges heat with the domestic water pipes as it flows through the heat exchanger, thus achieving the supply of domestic hot water. At this time, the heat exchange pipes are not connected to the heating pipes, the external circulation is interrupted, the water in the heating pipes is stagnant, and heating automatically stops until the use of domestic hot water ends. For the specific structure, please refer to the applicant's earlier patent application number CN201710624991.4 (publication number CN108061375A), Chinese invention patent "A Dual-Purpose Boiler Working System".

[0004] The combustion heat exchange device mainly includes a heat exchanger, a burner for supplying heat to the heat exchanger, and a fan for supplying air to the burner and exhausting flue gas.

[0005] However, after prolonged use, combustion heat exchangers on the market often experience ash accumulation on internal components, especially on the fan blades. When ash accumulates, the fan speed is significantly reduced, leading to incomplete combustion, high gas loss, and even carbon buildup that damages components and affects the machine's lifespan. Summary of the Invention

[0006] The first technical problem to be solved by the present invention is to provide a combustion heat exchange device that can avoid ash accumulation on internal components, in light of the current state of the prior art.

[0007] The second technical problem to be solved by the present invention is to provide a combustion heat exchange device capable of self-cleaning the filter.

[0008] The third technical problem to be solved by the present invention is to provide a control method for the above-mentioned combustion heat exchange device.

[0009] The fourth technical problem to be solved by the present invention is to provide a dual-purpose furnace using the above-mentioned combustion heat exchange device. The technical solution adopted by the present invention to solve the first technical problem is: a combustion heat exchange device, including a shell;

[0010] An inner shell is disposed within the outer shell, and there is a sandwich between the outer wall of the inner shell and the inner wall of the outer shell. The inner shell has an air inlet for communicating with the inner cavity of the inner shell and the sandwich.

[0011] A heat exchanger is disposed within the inner shell;

[0012] A burner, located inside the inner shell, is used to supply heat to the heat exchanger.

[0013] An air supply pipe, connected to the outer shell, is used to supply air into the interlayer;

[0014] A smoke exhaust duct, connected to the inner shell, is used to exhaust smoke from inside the inner shell; and

[0015] A fan is used to discharge the flue gas inside the inner shell through a flue pipe.

[0016] Its characteristic is that: the internal part of the air supply pipe has an air supply channel, and a filter is provided inside the air supply channel, the filter including...

[0017] The filter cartridge is coaxially arranged in the air supply channel and has multiple spaced filter holes.

[0018] A baffle plate covers the port of the filter cartridge facing the inlet of the supplementary airflow channel; and

[0019] The ash collection box has an annular ash collection groove inside, with the opening of the ash collection groove facing upward. The inner ring wall of the ash collection box is connected to the end edge of the filter cylinder facing the outlet of the make-up air channel, and the outer ring wall of the ash collection box is in close contact with the peripheral wall of the make-up air channel.

[0020] In order to preheat the cold air and cool the high-temperature flue gas, the exhaust pipe is at least partially housed within the make-up air pipe, and a make-up air passage is formed between the two. The baffle is provided with perforations for the exhaust pipe to pass through.

[0021] To further address the second technical problem mentioned above, the exhaust duct has multiple spaced vents at a distance from the filter cartridge. Valves are installed at both these vents and in the flow channel downstream of the vents inside the exhaust duct, ensuring that the combustion heat exchange device has at least two states:

[0022] In the first state, the flow channel inside the exhaust pipe located downstream of the vent is connected, and the vent is closed, so that the airflow inside the inner shell is discharged to the outside atmosphere through the flow channel inside the exhaust pipe.

[0023] In the second state, the flow channel inside the exhaust pipe located downstream of the vent is disconnected, and the vent is opened, so that the airflow inside the inner shell passes through the flow channel inside the exhaust pipe located upstream of the vent and the vent in sequence and blows towards the filter hole of the filter cartridge.

[0024] To simplify valve installation, the vent hole and the flow channel located downstream of the vent hole in the exhaust pipe share the same valve.

[0025] To allow the vent and the flow channel located downstream of the vent to share the same valve, the valve includes:

[0026] A fixed plate is arranged horizontally inside the exhaust duct at the flow channel downstream of the vent hole, and a first flow hole is provided therein;

[0027] The movable plate is arranged side by side with the fixed plate and has a second flow hole that is staggered with the first flow hole.

[0028] A movable sleeve, coaxially arranged inside the exhaust duct, is connected to the movable plate; and

[0029] A driving component is mounted on the fixed plate and is connected to the movable plate in a transmission manner to drive the movable plate and the movable sleeve to move relative to the fixed plate;

[0030] In the first state, the movable plate is moved away from the fixed plate so that the first flow hole and the second flow hole are connected; the movable sleeve covers the vent hole.

[0031] In the second state, the movable plate is pressed tightly against the fixed plate, so that the first flow hole and the second flow hole are disconnected; the movable sleeve releases its cover over the vent hole.

[0032] To facilitate the driving of the movable plate by the driving component, the driving component is a motor, and its power output shaft is a lead screw, which is threadedly connected to the middle position of the movable plate.

[0033] In order to automatically activate the self-cleaning function, a wind pressure sensor is installed in the flow channel upstream of the vent in the flue gas duct. The combustion heat exchange device has a controller. The wind pressure sensor, the burner, and the valves in the flow channel downstream of the vent in the flue gas duct are all electrically connected to the controller so that the controller can receive the signal collected by the wind pressure sensor and control the opening and closing of the burner and valves.

[0034] The technical solution adopted by the present invention to solve the third technical problem mentioned above is: a control method for the above-mentioned combustion heat exchange device, characterized by comprising the following steps:

[0035] (1) In the initial state, the controller starts the normal operation program: the burner and the fan are started, and the combustion heat exchange device is switched to the first state through the valve. At this time, the flow channel inside the flue pipe located downstream of the vent is connected, the vent is closed, and under the action of the fan, the air is supplemented into the jacket through the air supply channel after being filtered by the filter cartridge, and then supplemented into the inner shell through the air supply hole. The flue gas formed by the combustion of the burner is discharged to the outside atmosphere through the flue pipe. During the filtration process of the filter cartridge, the dust in the air will gradually block the filter hole.

[0036] (2) When the real-time wind pressure P monitored by the wind pressure sensor is less than the set value Pmin, the controller starts the self-cleaning program: first, the burner is turned off, and then the combustion heat exchange device is switched to the second state through the valve. At this time, the flow channel located downstream of the vent in the flue pipe is disconnected, the vent is opened, and the airflow in the inner shell blows through the flow channel located upstream of the vent in the flue pipe and the vent to the filter hole of the filter cartridge, which will blow away the dust that caused the blockage. The blown-away dust will gradually settle into the ash collection tank.

[0037] (3) When the real-time wind pressure P monitored by the wind pressure sensor is greater than the set value Pmax, the controller resumes normal operation.

[0038] The technical solution adopted by the present invention to solve the above-mentioned fourth technical problem is: a dual-purpose furnace using the above-mentioned combustion heat exchange device.

[0039] In order to provide domestic hot water and heating functions, the heat exchanger has a heat exchange channel;

[0040] Furthermore, it also includes

[0041] The heat exchanger has internal hot water channels and cold water channels that exchange heat with each other;

[0042] The heat exchange pipe includes a first heat exchange section and a second heat exchange section connected in sequence. At least part of the first heat exchange section passes through the heat exchange channel of the heat exchanger, and at least part of the second heat exchange section passes through the hot water channel of the heat exchanger.

[0043] The heating inlet pipe and the heating outlet pipe are respectively connected to the two ends of the first heat exchange section, and are respectively used to connect to the two ends of the external heating pipeline.

[0044] The domestic water inlet pipe and the domestic water outlet pipe are respectively connected to both ends of the cold water passage of the heat exchanger; and

[0045] A delivery pump is installed on the first heat exchange section.

[0046] Valves are installed on both the second heat exchange section and the heating water outlet pipe to ensure that the dual-purpose boiler has at least two operating modes:

[0047] In domestic hot water mode, the second heat exchange section is connected, and the heating outlet pipe is disconnected.

[0048] In heating mode, the second heat exchange section is disconnected, while the heating outlet pipe is connected.

[0049] Compared with the prior art, the advantages of the present invention are as follows:

[0050] (1) A filter consisting of a filter cartridge, a baffle and a dust collection box is installed in the air supply channel. During the air flow through the air supply channel, the filter cartridge will filter the dust in the air, and some of the dust will settle into the dust collection trough under the action of gravity.

[0051] (2) By opening multiple spaced vents in the exhaust duct directly opposite the filter cartridge, and installing valves in the vents and the flow channel downstream of the vents inside the exhaust duct:

[0052] During normal operation, the combustion heat exchange device can be switched to the first state through the valve. At this time, the flow channel inside the flue pipe located downstream of the vent is connected, the vent is closed, and under the action of the fan, the air is supplied to the jacket through the air supply channel after being filtered by the filter cartridge, and then supplied to the inner shell through the air supply hole. The flue gas generated by the burner combustion is discharged to the outside atmosphere through the flue pipe. During the filtration process of the filter cartridge, the dust in the air will gradually clog the filter holes.

[0053] When self-cleaning is required, the combustion heat exchange device can be switched to the second state through the valve. At this time, the flow channel located downstream of the vent in the flue pipe is disconnected, the vent is opened, and the airflow in the inner shell blows through the flow channel located upstream of the vent in the flue pipe and the vent to the filter hole of the filter cartridge, which will blow away the dust that is causing blockage. The blown-away dust will gradually settle into the ash collection trough. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the structure of the dual-purpose furnace of the present invention in its first state (arrows indicate the direction of airflow);

[0055] Figure 2 for Figure 1 Partial three-dimensional exploded view of the combustion heat exchange device (arrows indicate airflow direction);

[0056] Figure 3 for Figure 1 A partially enlarged view of the combustion heat exchange device (arrows indicate airflow direction);

[0057] Figure 4 for Figure 3 A schematic diagram of the structure of the combustion heat exchanger after it switches to the second state (arrows indicate the direction of airflow). Detailed Implementation

[0058] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0059] like Figures 1 to 4 The image shows a preferred embodiment of the dual-purpose furnace of the present invention. The dual-purpose furnace includes a combustion heat exchange device 1, a heat exchanger 2, a heat exchange pipe 3, a heating water inlet pipe 4a, a heating water outlet pipe 4b, a domestic water inlet pipe 5a, a domestic water outlet pipe 5b, a delivery pump 6, and a three-way valve 7.

[0060] The combustion heat exchange device 1 includes an outer shell 11, an inner shell 12, a heat exchanger 13, a burner 14, a gas supply pipe 15, a flue gas pipe 16, a fan 17, a filter 18, and a valve 19.

[0061] Specifically, the inner shell 12 is disposed inside the outer shell 11, and there is a sandwich 111 between the outer wall of the inner shell 12 and the inner wall of the outer shell 11; the bottom of the inner shell 11 is connected to a gas pipe 121 for supplying gas to the burner 14, and a proportional valve 1211 for adjusting the amount of gas is installed on the gas pipe 121; the bottom wall of the inner shell 12 has a plurality of gas supply holes 122 for connecting the inner cavity of the inner shell 12 and the sandwich 111.

[0062] The heat exchanger 13 is located in the middle of the inner cavity of the inner shell 12, and has a heat exchange channel inside.

[0063] The burner 14 is located in the lower part of the inner cavity of the inner shell 12 and is used to supply heat to the heat exchanger 13.

[0064] The air supply pipe 15 is connected to the top of the outer casing 11 and is used to supply air into the interlayer 111.

[0065] The exhaust duct 16 is connected to the top of the inner shell 12 and is used to exhaust the flue gas inside the inner shell 12. A wind pressure sensor 162 is installed at the inlet of the exhaust duct 16 to monitor the wind pressure at the inlet of the exhaust duct 16. In this embodiment, the exhaust duct 16 is housed in the air supply duct 15, and an air supply channel 151 is formed between the outer peripheral wall of the exhaust duct 16 and the inner peripheral wall of the air supply duct 15. In this way, the cold air in the air supply channel 151 can fully exchange heat with the high temperature flue gas in the exhaust duct 16, thereby preheating the cold air while cooling the high temperature flue gas.

[0066] The fan 17 is installed at the inlet of the exhaust duct 16 to discharge the flue gas inside the inner shell 12 through the exhaust duct 16.

[0067] The filter 18 is disposed within the air supply channel 151 and includes a filter cylinder 181, a baffle 182, and a dust collection box 183. The filter cylinder 181 is vertically and coaxially arranged within the air supply channel 151. The peripheral wall of the filter cylinder 181 has multiple spaced filter holes 1811. The exhaust pipe 16 has multiple spaced ventilation holes 161 at a position directly opposite the filter cylinder 181. The baffle 182 covers the top end of the filter cylinder 181 and has a through hole 1821 for the exhaust pipe 16 to pass through. The dust collection box 183 has an annular dust collection groove 1831 inside, with the opening of the dust collection groove 1831 facing upward. The inner annular wall of the dust collection box 183 is connected to the bottom edge of the filter cylinder 181, and the outer annular wall of the dust collection box 183 is in close contact with the inner peripheral wall of the air supply pipe 15. The filter 18 described above can effectively filter dust in the intake air, preventing dust from directly entering the machine. On the one hand, it can ensure complete combustion and prevent carbon buildup from damaging parts, and on the other hand, it can reduce the noise of the whole machine.

[0068] Valve 19 includes a fixed plate 191, a movable plate 192, a movable sleeve 193, and a drive component 194. The fixed plate 191 is arranged laterally inside the exhaust duct 16 at the flow channel above the vent 161. The periphery of the fixed plate 191 has a plurality of first flow holes 1911 arranged circumferentially at intervals. The movable plate 192 is arranged side by side below the fixed plate 191. The middle of the movable plate 192 has a plurality of second flow holes 1921 arranged circumferentially at intervals, which are staggered with the first flow holes 1911. The movable sleeve 193 is arranged vertically and coaxially inside the exhaust duct 16, and its top end is connected to the bottom wall of the movable plate 192. The drive component 194 is a motor, mounted on the fixed plate 191, and has a downwardly extending power output shaft, which is a lead screw 1941, threadedly connected to the middle position of the movable plate 192.

[0069] The starter 194 drives the lead screw 1941 to rotate, which in turn drives the movable plate 192 and the movable sleeve 193 to rise and fall relative to the fixed plate 191, so that the combustion heat exchange device 1 has at least two states:

[0070] In the first state, such as Figure 3 As shown, the movable plate 192 is moved away from the fixed plate 191 so that the first flow hole 1911 and the second flow hole 1921 are connected, thereby connecting the flow channel inside the smoke exhaust pipe 16 located above (i.e., lowered) the vent hole 161. At the same time, the movable sleeve 193 covers the vent hole 161 so that the vent hole 161 is closed. In this way, the airflow inside the inner shell 12 can be discharged to the outside atmosphere through the flow channel inside the smoke exhaust pipe 16.

[0071] In the second state, such as Figure 4As shown, the movable plate 192 is tightly attached to the fixed plate 191, so that the first flow hole 1911 and the second flow hole 1921 are disconnected, thereby disconnecting the flow channel inside the exhaust pipe 16 located above (i.e., downward) the vent hole 161. At the same time, the movable sleeve 193 removes the cover of the vent hole 161, so that the vent hole 161 is opened. In this way, the airflow inside the inner shell 12 passes through the flow channel inside the exhaust pipe 16 located below (i.e. upstream) the vent hole 161 and blows towards the filter hole 1811 of the filter cartridge 181.

[0072] In addition, the above-mentioned combustion heat exchange device 1 has a controller, and the wind pressure sensor 162, the burner 14 and the drive unit 194 are all electrically connected to the controller so that the controller can receive the signal collected by the wind pressure sensor 162 and control the start and stop of the burner 14 and the drive unit 194.

[0073] The heat exchanger 2 has a hot water channel and a cold water channel that exchange heat with each other.

[0074] The heat exchange pipe 3 is a circulating pipe, including a first heat exchange section 31 and a second heat exchange section 32 connected in sequence. Specifically, the first heat exchange section 31 passes through the heat exchange channel of the heat exchanger 13, and the second heat exchange section 32 passes through the hot water channel of the heat exchanger 2.

[0075] The heating inlet pipe 4a and the heating outlet pipe 4b are respectively connected to the inlet end and the outlet end of the first heat exchange section 31, and are used to connect to both ends of the external heating pipeline.

[0076] The domestic water inlet pipe 5a and the domestic water outlet pipe 5b are respectively connected to the two ends of the cold water channel of the heat exchanger 2.

[0077] The delivery pump 6 is installed on the first heat exchange section 31 and can deliver water from the inlet end of the first heat exchange section 31 to the outlet end of the first heat exchange section 31.

[0078] The three-way valve 7 has an inlet end, a first outlet end, and a second outlet end. The inlet end of the three-way valve 7 is connected to the outlet end of the first heat exchange section 31, the first outlet end of the three-way valve 7 is connected to the inlet end of the second heat exchange section 32, and the second outlet end of the three-way valve 7 is connected to the heating outlet pipe 4b. The on / off state of the second heat exchange section 32 and the heating outlet pipe 4b can be controlled by adjusting the three-way valve 7.

[0079] By adjusting the three-way valve 7, the dual-purpose furnace has at least two operating modes:

[0080] In the domestic hot water mode, the second heat exchange section 32 is connected and the heating outlet pipe 4b is disconnected, so that the heat exchange pipe 3 forms a separate circulation loop, that is, the internal circulation mentioned in the background art.

[0081] In heating mode, the second heat exchange section 32 is disconnected, and the heating outlet pipe 4b is connected, so that the heating inlet pipe 4a, the first heat exchange section 31, the heating outlet pipe 4b and the external heating pipeline together form a circulation loop, which is the external circulation mentioned in the background art.

[0082] The present invention also provides a control method for the above-mentioned dual-purpose furnace, comprising the following steps:

[0083] (1) In the initial state, the controller starts the normal operation program: the burner 14 and the fan 17 are started, and the control drive 194 switches the combustion heat exchange device 1 to the first state. At this time, as Figure 1 and Figure 3 As shown, the flow channel inside the exhaust duct 16 above the vent 161 is connected. The vent 161 is closed. Under the action of the fan 17, the air is supplied to the interlayer 111 after being filtered by the filter cartridge 181 through the supplementary flow channel 151, and then supplied to the inner shell 12 through the supplementary air hole 122. The flue gas generated by the combustion of the burner 14 is discharged to the outside atmosphere through the exhaust duct 16. During the filtration process of the filter cartridge 181, the dust in the air will gradually block the filter hole 1811 and affect the air intake of the supplementary flow channel 151. Some of the dust will settle into the ash collection tank 1831 under the action of gravity.

[0084] (2) During normal operation, when the real-time wind pressure P detected by the wind pressure sensor 162 is less than the set value Pmin, it is determined that the air intake of the supplementary airflow channel 151 is blocked. The controller starts the self-cleaning program: first, the burner 14 is turned off, and then the drive unit 194 is controlled to switch the combustion heat exchange device 1 to the second state. At this time, the flow channel inside the flue pipe 16 above the vent hole 161 is disconnected, the vent hole 161 is opened, and the airflow in the inner shell 12 passes through the flow channel inside the flue pipe 16 below the vent hole 161 and the vent hole 161 in sequence and blows towards the filter hole 1811 of the filter cartridge 181, which blows away the dust that caused the blockage. The blown-away dust will gradually settle into the ash collection tank 1831, thereby achieving the unobstructed flow of the filter 18.

[0085] (3) When the real-time wind pressure P monitored by the wind pressure sensor 162 is greater than the set value Pmax, the controller resumes normal operation.

Claims

1. A combustion heat exchange device, comprising: Outer shell (11); An inner shell (12) is disposed inside the outer shell (11). There is a sandwich layer (111) between the outer wall of the inner shell (12) and the inner wall of the outer shell (11). The inner shell (12) has an air inlet (122) for connecting the inner cavity of the inner shell (12) and the sandwich layer (111). A heat exchanger (13) is disposed inside the inner shell (12); A burner (14) is disposed inside the inner shell (12) for supplying heat to the heat exchanger (13); An air supply pipe (15) is connected to the outer shell (11) and is used to supply air into the interlayer (111); Smoke exhaust pipe (16) is connected to the inner shell (12) for exhausting the smoke inside the inner shell (12); as well as A fan (17) is used to discharge the flue gas inside the inner shell (12) through the exhaust pipe (16); The feature is that the air supply pipe (15) has an internal air supply channel (151), and a filter (18) is provided inside the air supply channel (151). The filter (18) includes... The filter cartridge (181) is coaxially arranged in the supplementary airflow channel (151) and has a plurality of spaced filter holes (1811). A baffle (182) covers the port of the filter cartridge (181) facing the inlet of the supplementary airflow channel (151); and The ash collection box (183) has an annular ash collection groove (1831) inside, with the opening of the ash collection groove (1831) facing upward. The inner ring wall of the ash collection box (183) is connected to the end edge of the filter cylinder (181) facing the outlet of the supplementary airflow channel (151), and the outer ring wall of the ash collection box (183) is in close contact with the peripheral wall of the supplementary airflow channel (151). The exhaust pipe (16) is partially housed within the gas supply pipe (15), and a gas supply channel (151) is formed between the two. The baffle (182) has a perforation (1821) through which the exhaust pipe (16) passes. The exhaust pipe (16) has multiple spaced vent holes (161) at the position opposite to the filter cylinder (181). Valves are provided in both the vent holes (161) and the flow channel inside the exhaust pipe (16) downstream of the vent holes (161), so that the combustion heat exchange device has at least two states: In the first state, the flow channel inside the exhaust pipe (16) downstream of the vent (161) is connected, and the vent (161) is closed so that the airflow inside the inner shell (12) is discharged to the outside atmosphere through the flow channel inside the exhaust pipe (16); In the second state, the flow channel inside the exhaust pipe (16) downstream of the vent (161) is disconnected, and the vent (161) is opened so that the airflow inside the inner shell (12) passes through the flow channel inside the exhaust pipe (16) upstream of the vent (161) and the vent (161) and blows toward the filter hole (1811) of the filter cylinder (181).

2. The combustion heat exchange device according to claim 1, characterized in that: The ventilation hole (161) and the flow channel located downstream of the exhaust pipe (16) share the same valve (19).

3. The combustion heat exchange device according to claim 2, characterized in that: The valve (19) includes A fixed plate (191) is arranged laterally inside the exhaust pipe (16) at the flow channel downstream of the vent (161), and a first flow hole (1911) is provided therein; The movable plate (192) is arranged side by side with the fixed plate (191) and has a second flow hole (1921) that is staggered with the first flow hole (1911); The movable sleeve (193) is coaxially arranged inside the exhaust pipe (16) and connected to the movable plate (192); as well as A driving component (194) is mounted on the fixed plate (191) and is connected to the movable plate (192) for driving the movable plate (192) and the movable sleeve (193) to move relative to the fixed plate (191). In the first state, the movable plate (192) is moved away from the fixed plate (191) so that the first flow hole (1911) and the second flow hole (1921) are connected; the movable sleeve (193) covers the vent hole (161). In the second state, the movable plate (192) is pressed against the fixed plate (191) so that the first flow hole (1911) and the second flow hole (1921) are disconnected; the movable sleeve (193) releases the cover of the vent hole (161).

4. The combustion heat exchange device according to claim 3, characterized in that: The driving component (194) is a motor, and its power output shaft is a lead screw (1941), which is threadedly connected to the middle position of the movable plate (192).

5. The combustion heat exchange device according to any one of claims 1 to 4, characterized in that: A wind pressure sensor (162) is installed inside the flue gas duct (16) at the flow channel upstream of the vent (161). The combustion heat exchange device has a controller. The wind pressure sensor (162), the burner (14), and the valves at the flow channel downstream of the vent (161) inside the flue gas duct (16) are all electrically connected to the controller so that the controller can receive the signal collected by the wind pressure sensor (162) and control the opening and closing of the burner (14) and the valves.

6. A control method for the combustion heat exchange device according to claim 5, characterized in that... It includes the following steps: (1) In the initial state, the controller starts the normal operation program: the burner (14) and the fan (17) are started, and the combustion heat exchange device is switched to the first state through the valve. At this time, the flow channel inside the flue pipe (16) downstream of the vent hole (161) is connected, the vent hole (161) is closed, and under the action of the fan (17), the air is filtered through the filter cartridge (181) through the replenishment flow channel (151) and then replenished into the jacket (111), and then replenished into the inner shell (12) through the replenishment air hole (122). The flue gas formed by the combustion of the burner (14) is discharged to the outside atmosphere through the flue pipe (16). During the filtration process of the filter cartridge (181), the dust in the air will gradually block the filter hole (1811). (2) When the real-time wind pressure P monitored by the wind pressure sensor (162) is less than the set value Pmin, the controller starts the self-cleaning program: first, the burner (14) is turned off, and then the combustion heat exchange device is switched to the second state through the valve. At this time, the flow channel inside the flue pipe (16) located downstream of the vent (161) is disconnected, the vent (161) is opened, and the airflow in the inner shell (12) passes through the flow channel inside the flue pipe (16) located upstream of the vent (161) and the vent (161) and blows towards the filter hole (1811) of the filter cartridge (181), which will blow away the dust that caused the blockage. The blown-away dust will gradually settle into the ash collection tank (1831). (3) When the real-time wind pressure P monitored by the wind pressure sensor (162) is greater than the set value Pmax, the controller resumes normal operation.

7. A dual-purpose furnace employing the combustion heat exchange device according to any one of claims 1 to 5.

8. The dual-purpose furnace according to claim 7, characterized in that: The heat exchanger (13) has a heat exchange channel; Furthermore, it also includes The heat exchanger (2) has a hot water channel and a cold water channel that exchange heat with each other. The heat exchange pipe (3) includes a first heat exchange section (31) and a second heat exchange section (32) connected in sequence. The first heat exchange section (31) passes through the heat exchange channel of the heat exchanger (13) in at least part, and the second heat exchange section (32) passes through the hot water channel of the heat exchanger (2) in at least part. The heating inlet pipe (4a) and the heating outlet pipe (4b) are respectively connected to the two ends of the first heat exchange section (31) and are respectively used to connect to the two ends of the external heating pipeline. A domestic water inlet pipe (5a) and a domestic water outlet pipe (5b) are respectively connected to both ends of the cold water passage of the heat exchanger (2); and A transfer pump (6) is installed on the first heat exchange section (31); Valves are provided on the second heat exchange section (32) and the heating outlet pipe (4b) to enable the dual-purpose boiler to have at least two operating modes: In the domestic hot water mode, the second heat exchange section (32) is connected, and the heating outlet pipe (4b) is disconnected; In heating mode, the second heat exchange section (32) is disconnected, and the heating outlet pipe (4b) is connected.

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