Combustion device and household electrical appliance

Abstract

The utility model relates to the technical field of household appliances, and discloses a combustion device and a household appliance, and the combustion device comprises a combustor which comprises a first combustion hole and a second combustion hole; an air outlet gap is formed between the first combustion hole and the second combustion hole, and the premixing structure comprises a first premixing cavity communicating with the air outlet gap and a second premixing cavity communicating with the second combustion hole; the air inlet structure comprises a fan, a first air channel and a second air channel, wherein the first air channel and the second air channel are communicated between the fan and the first premixing cavity and between the fan and the second premixing cavity. The gas conveying structure comprises a first gas channel and a second gas channel which are communicated between the gas proportional valve and the first premixing cavity and between the gas proportional valve and the second premixing cavity, and the opening area of the air outlet gap is larger than that of the second combustion hole. The corresponding gas channels are opened when different thermal load requirements are met, the working mode that semi-premixed combustion and full-premixed combustion are combined is achieved, and the device can adapt to combustion conditions in different working load states.

Description

Technical Field

[0001] The utility model relates to the technical field of household electrical appliances, in particular to a combustion device and household electrical appliances. Background Art

[0002] Most of the existing household appliances, such as wall-mounted boilers and gas water heaters, heat water through combustion devices. At present, combustion devices based on full premixed combustion technology are widely used. They mainly mix the gas and air into a uniform premixed gas in advance, and burn the premixed gas in the burner to release heat and heat the water temperature. Since the gas and oxygen have been fully mixed in advance, the combustion efficiency can be improved.

[0003] However, the existing fully premixed burner has a single working mode and cannot adapt to the combustion conditions under different working loads. Under high load working conditions, the fully premixed combustion temperature is too high and nitrogen oxides are easily produced. Under low load working conditions, the fully premixed combustion flame is unstable and it is easy to backfire, flameout or burn parts. Utility Model Content

[0004] In view of this, the utility model provides a combustion device and household appliance to solve the problem of full premixed combustion in the prior art, that the combustion temperature is too high and nitrogen oxides are easily generated under high load conditions, and that backfires and flameouts are easy under low load conditions.

[0005] In a first aspect, the utility model provides a combustion device, the combustion device comprising:

[0006] A burner, comprising a combustion chamber and a plurality of groups of combustion holes arranged at intervals in the combustion chamber, each group of combustion holes comprising a first combustion hole and a second combustion hole located in the first combustion hole;

[0007] A premixing structure, wherein an air outlet gap is formed between the first combustion hole and the second combustion hole, and the premixing structure comprises a first premixing chamber connected to the air outlet gap, and a second premixing chamber connected to the second combustion hole;

[0008] The air inlet structure includes a fan, a first air passage connected between the fan and the first premixing chamber, and a second air passage connected between the fan and the second premixing chamber;

[0009] The gas delivery structure includes a gas proportioning valve, a first gas passage communicating between the gas proportioning valve and the first premixing chamber, and a second gas passage communicating between the gas proportioning valve and the second premixing chamber;

[0010] Among them, the opening area of ​​the air outlet gap is larger than the opening area of ​​the second combustion hole, the first air channel and the second air channel are normally open, and the first gas channel and the second gas channel are selectively opened and closed.

[0011] Beneficial effects: The gap between the first combustion hole and the second combustion hole, and the second combustion hole constitute two fire holes with different opening areas, and by setting two premixing chambers, two air channels and two gas channels, the corresponding gas channels are opened respectively when different heat load requirements are met to meet different combustion conditions, and the corresponding gas channels are opened for combustion at high load and low load respectively to realize a working mode combining semi-premixed combustion and full premixed combustion, which can adapt to the combustion conditions under different working load states. In different working modes, the two air channels are always in a normally open state, which can provide sufficient oxygen for combustion, and use air to cool the full premixed combustion, reduce the combustion temperature, and reduce the production of nitrogen oxides. Semi-premixed combustion is used to compensate for the problem that the flame of the full premixed combustion is unstable, easy to flash back, and burn parts during low load combustion, so as to achieve the technical effect of stable combustion at full load, improve thermal efficiency, and effectively solve the problem that the full premixed combustion in the prior art has too high combustion temperature and is easy to produce nitrogen oxides under high load state, and is easy to flash back and flame out under low load state.

[0012] In an optional embodiment, the combustion device has a high-load combustion mode and a low-load combustion mode;

[0013] When the combustion device is in a high-load combustion mode, the first gas channel is opened and the second gas channel is closed. The air transported through the first air channel and the gas transported through the first gas channel are premixed in the first premixing chamber, ejected from the air outlet gap and ignited, and the air transported through the second air channel directly escapes from the second combustion hole to the combustion chamber.

[0014] When the combustion device is in the low-load combustion mode, the first gas channel is closed and the second gas channel is opened. The air transported through the second air channel and the gas transported through the second gas channel are premixed in the second premixing chamber, ejected from the second combustion hole and ignited, and the air transported through the first air channel directly escapes from the air outlet gap to the combustion chamber.

[0015] Beneficial effects: When the heat load demand is large, the combustion device starts the high-load combustion mode, the first gas channel is opened, and the second gas channel is closed. The air from the first air channel and the gas from the first gas channel are premixed in the first premixing chamber, and then reach the combustion chamber through the gap between the two combustion holes for combustion, thereby achieving fully premixed combustion. The gas combustion is premixed with all the required air, the flame propagates quickly, and the combustion temperature is high. When used in water heaters, it can bring about faster and more heat exchange, high water heating capacity, higher heat exchange efficiency, and technical effects of saving gas. At the same time, the second air channel will transport part of the air, which passes through the second premixing chamber and escapes from the second combustion hole to the combustion chamber, thereby taking away part of the heat from the combustion environment, lowering the combustion temperature, reducing nitrogen oxides, and reducing the production of harmful substances. When the heat load demand is small, the combustion device starts the small load combustion mode, the second gas channel is opened, the first gas channel is closed, the air in the second air channel and the gas in the second gas channel are premixed in the second premixing chamber, and then ejected from the second combustion hole for combustion, performing semi-premixed combustion. Under small load conditions, the gas is partially premixed with the required air, and the air outlet gap continuously provides secondary air required for combustion, maintaining continuous and stable combustion in the combustion chamber. The flame is more stable and not prone to extinguishing and backfire. Semi-premixed combustion is used to compensate for the problems of unstable flame during small load combustion of full premixed combustion, easy backfire and burning of parts, and unstable heating.

[0016] In an optional embodiment, the volume of the first premixing chamber is greater than the volume of the second premixing chamber.

[0017] Beneficial effect: By setting the volume of the first premixing chamber to be larger than the volume of the second premixing chamber, it can be effectively ensured that in the high-load combustion mode, the first premixing chamber can provide sufficient mixed combustion gas to the air outlet gap. The present application sets fire holes and premixing chambers of different sizes, and can select premixing chambers of different sizes for gas and air mixing according to different workload states, and corresponding fire holes for ignition and combustion, thereby meeting different combustion conditions.

[0018] In an optional embodiment, the gas proportioning valve has a first gas outlet and a second gas outlet, and the second premixing chamber has a gas inlet and an air inlet;

[0019] One end of the first gas channel is connected to the first gas outlet, and the other end is connected to the upstream position of the first air channel; one end of the second gas channel is connected to the second gas outlet, and the other end is connected to the gas inlet;

[0020] The fan has a first air outlet and a second air outlet. One end of the first air channel is connected to the first air outlet, and the other end is connected to the first premixing chamber; one end of the second air channel is connected to the second air outlet, and the other end is connected to the air inlet.

[0021] Beneficial effects: The gas proportional valve can adopt a one-inlet and two-outlet structure, the inlet of the gas proportional valve is connected to the air inlet joint, the air inlet joint is connected to the gas channel in the user's home, and the two gas outlets of the gas proportional valve are connected to the first gas channel and the second gas channel respectively. The gas ratio allocated to the first gas channel and the second gas channel can be adjusted by controlling the opening of the gas proportional valve. In addition, the first gas channel is connected to the upstream position of the first air channel to achieve its communication with the first premixing chamber, so that the gas can be mixed with the air in the first air channel in advance before entering the first premixing chamber, thereby extending the mixing path and mixing time of the gas and air, so that the gas and air can be mixed more fully.

[0022] In an optional embodiment, the fan comprises:

[0023] impeller;

[0024] The volute has an impeller disposed in it. The volute includes a spiral portion and an air outlet portion extending in a tangential direction of the spiral portion. The port of the air outlet portion constitutes a first air outlet. A second air outlet is provided on a side wall of the air outlet portion.

[0025] Beneficial effect: By adopting the port of the air outlet part to form the first air outlet and opening the second air outlet on the side wall of the air outlet part, the first air outlet can provide a larger air volume, ensuring that sufficient oxygen can be provided for combustion in the high-load combustion mode. At the same time, it can also effectively ensure that in the low-load combustion mode, secondary oxygen is continuously supplied to the combustion, thereby maintaining the continuous and stable combustion in the combustion chamber and avoiding the phenomenon of backfire and flameout.

[0026] In an optional embodiment, the first air channel includes a connecting section and a mixing section, and the connecting section is connected between the first air outlet of the fan and the mixing section;

[0027] A gas inlet is arranged on a side wall of one end of the connecting section away from the mixing section, and the first gas channel is connected between the gas inlet and the first gas outlet.

[0028] Beneficial effect: The first air channel adopts the design of a connecting section and a mixing section, which facilitates the connection with the first air outlet and can effectively ensure the mixing effect of air and gas in the first air channel. By opening the gas inlet at the end of the connecting section away from the mixing section, the gas enters from the upstream of the first air channel, thereby extending the mixing path and mixing time of the gas and air, so that the gas and air can be fully mixed for full premixed combustion.

[0029] In an optional embodiment, a plurality of retaining ribs are arranged at intervals in the first air channel along the gas flow direction;

[0030] A plurality of retaining ribs are alternately arranged on opposite sides of the first air passage to form a serpentine air flow passage in the first air passage.

[0031] Beneficial effect: By setting up multiple baffles in the first air channel, a spoiler effect can be achieved, and by arranging the multiple baffles alternately on the opposite sides of the first air channel, a serpentine airflow channel can be formed in the first air channel, further extending the flow path of the mixed gas in the first air channel, so that the gas and air can be fully mixed to perform fully premixed combustion.

[0032] In an optional embodiment, the burner comprises:

[0033] A first combustion plate having a plurality of first combustion holes spaced apart thereon;

[0034] A second combustion plate is arranged below the first combustion plate, a plurality of combustion cores are arranged at intervals on the second combustion plate, and a second combustion hole is arranged in the combustion core;

[0035] The inner diameter of the first combustion hole is larger than the outer diameter of the combustion core, and the multiple combustion cores are arranged in a one-to-one correspondence in the multiple first combustion holes, and the outer periphery of the combustion core and the inner periphery of the first combustion holes form an air outlet gap.

[0036] Beneficial effect: A plurality of first combustion holes are arranged on the first combustion plate, a plurality of combustion cores are arranged at intervals on the second combustion plate, a second combustion hole is formed inside the combustion core, the aperture of the first combustion hole is larger than the maximum outer diameter of the combustion core, and the plurality of combustion cores are correspondingly inserted into the plurality of first combustion holes, so that the first combustion plate and the second combustion plate can be nested to form a combined combustion plate, and the gap formed when the first combustion hole and the combustion core are nested constitutes two independent fire holes with the second combustion hole, one of the two fire holes is for spraying out the mixed combustion gas, and the other is for spraying out air. Specifically, under high load conditions, the gap between the first combustion hole and the combustion core is used to discharge the mixed combustion gas, and the second combustion hole is used to discharge air. Under low load conditions, the gap between the first combustion hole and the combustion core is used to discharge air, and the second combustion hole is used to discharge the mixed combustion gas, so as to meet different heat load requirements.

[0037] In an optional embodiment, the premix structure includes:

[0038] A first premixing shell has a first premixing chamber therein, the upper end of the first premixing shell is open, and the lower end is connected to the first air channel;

[0039] The burner cover is arranged at the open end of the first premixing shell so that the first premixing chamber is communicated with the air outlet gap.

[0040] Beneficial effect: The upper end of the first premixing shell adopts an open design, which can increase the outlet area of ​​the first premixing chamber, and by installing the burner cover on the open end of the first premixing shell, the first premixing chamber can be directly connected to the air outlet gap, further simplifying the structure, while ensuring that the gas in the first premixing chamber can escape from the air outlet gap more smoothly and efficiently.

[0041] In an optional embodiment, the premixing structure further includes:

[0042] A second premixing shell has a second premixing chamber therein, and the second premixing shell is fixedly mounted on the first premixing shell;

[0043] The second combustion plate comprises a plurality of distribution strips arranged at intervals, each distribution strip is provided with a plurality of combustion cores at intervals, and the distribution strip has a distribution channel inside, which is communicated with the second combustion hole in the combustion core;

[0044] The ends of the plurality of distribution strips on the same side are fixed to the second premixing shell, and each distribution channel is communicated with the second premixing chamber.

[0045] Beneficial effect: The second combustion plate adopts a design of multiple distribution strips arranged at intervals, so that the gas in the first premixing chamber can pass through the gap between two adjacent distribution strips, enter the air outlet gap between the first combustion hole and the second combustion hole and be discharged, avoiding the problem that the air outlet gap is completely blocked by the whole closed plate structure, so that the gas in the first premixing chamber cannot enter the air outlet gap. In addition, by fixing the ends of the same side of the multiple distribution strips on the second premixing shell, it is more convenient to assemble.

[0046] In a second aspect, the utility model further provides a household appliance, including any one of a wall-mounted boiler and a gas water heater, the household appliance including:

[0047] shell;

[0048] The combustion device of any of the above embodiments is used to heat water. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0050] Figure 1 It is a schematic diagram of the assembly of the burner, the premixing structure and the first air passage in the embodiment of the utility model;

[0051] Figure 2 It is a schematic diagram of the assembly of the burner, the fan, the first gas channel, the second gas channel, half of the first premixing shell and the first air channel in the embodiment of the utility model;

[0052] Figure 3 It is a schematic diagram of the assembly of the first combustion plate, half of the first premixing shell, the first air channel, and the shell body of the second premixing shell in the embodiment of the utility model;

[0053] Figure 4 An exploded view of a portion of the structure of a combustion device in an embodiment of the utility model;

[0054] Figure 5 for Figure 4 A schematic diagram of the assembly of the combustion device and the casing;

[0055] Figure 6 for Figure 5 Schematic diagram of gas flow direction of the combustion device in the high-load combustion mode;

[0056] Figure 7 for Figure 5 Schematic diagram of gas flow direction when the combustion device is in a low-load combustion mode;

[0057] Figure 8 for Figure 5 A schematic diagram of the structure of the combustion device and the gas proportional valve after being assembled at an angle shown in FIG.

[0058] Fig. 9 for Figure 8 A schematic structural diagram of an angle of the combustion device shown in FIG. 1 after removing half of the first air passage and the first premixing shell;

[0059] Fig.10 for Fig. 9 Axonometric view from another angle.

[0060] Description of reference numerals:

[0061] 10. burner; 101. combustion chamber; 102. combustion hole; 1021. first combustion hole; 1022. second combustion hole; 11. first combustion plate; 12. second combustion plate; 120. combustion core; 121. distribution strip;

[0062] 20. premixing structure; 201. first premixing chamber; 202. second premixing chamber; 21. first premixing shell; 22. second premixing shell;

[0063] 30. air inlet structure; 31. fan; 311. first air outlet; 312. second air outlet; 32. first air passage; 321. connecting section; 3211. gas inlet; 322. mixing section; 3221. retaining rib; 33. second air passage;

[0064] 40. Gas delivery structure; 41. Gas proportional valve; 42. First gas channel; 43. Second gas channel;

[0065] 50. Cover. DETAILED DESCRIPTION

[0066] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0067] At present, combustion devices based on full premixed combustion technology are widely used. They mainly premix the gas and air into a uniform premixed gas, and burn the premixed gas in the burner to release heat and heat the water temperature. Since the gas and oxygen have been fully mixed in advance, the combustion efficiency can be improved.

[0068] However, the existing fully premixed burner has a single combustion structure, a fixed fire hole size, and a single working mode, which cannot adapt to the combustion conditions under different working loads. When working under high load, the fully premixed combustion temperature is too high, which is easy to produce nitrogen oxides. When working under low load, the gas flow rate through the fire hole is low during low fire combustion, the flame is reduced, the flame is unstable, and it is easy to flash back, flameout, or burn parts.

[0069] Combine the following Figures 1 to 10 , describing an embodiment of the utility model.

[0070] According to an embodiment of the present invention, on one hand, the present invention provides a combustion device, which includes: a burner 10, a premixing structure 20, an air intake structure 30, and a gas delivery structure 40.

[0071] Specifically, the burner 10 includes a combustion chamber 101 and a plurality of groups of combustion holes 102 arranged at intervals in the combustion chamber 101, each group of combustion holes 102 includes a first combustion hole 1021 and a second combustion hole 1022 located in the first combustion hole 1021; an air outlet gap is formed between the first combustion hole 1021 and the second combustion hole 1022, and the premixing structure 20 includes a first premixing chamber 201 connected to the air outlet gap, and a second premixing chamber 202 connected to the second combustion hole 1022; the air inlet structure 30 includes a fan 31, and a second premixing chamber 202 connected between the fan 31 and the first premixing chamber 201. The gas delivery structure 40 includes a first air passage 32 connected between the gas proportioning valve 41 and the first premixing chamber 201, and a second air passage 33 connected between the fan 31 and the second premixing chamber 202; the gas delivery structure 40 includes a gas proportioning valve 41, and a first gas passage 42 connected between the gas proportioning valve 41 and the first premixing chamber 201, and a second gas passage 43 connected between the gas proportioning valve 41 and the second premixing chamber 202; wherein, the opening area of ​​the air outlet gap is larger than the opening area of ​​the second combustion hole 1022, the first air passage 32 and the second air passage 33 are normally open, and the first gas passage 42 and the second gas passage 43 are selectively opened and closed.

[0072] In the above embodiment, the gap between the first combustion hole 1021 and the second combustion hole 1022, and the second combustion hole 1022 constitute two fire holes with different opening areas, and by setting two premixing chambers, two air channels and two gas channels, the corresponding gas channels are opened respectively when different heat load requirements are met to meet different combustion conditions, and the corresponding gas channels are opened for combustion at high load and low load respectively to realize a working mode combining semi-premixed combustion and full premixed combustion, which can adapt to the combustion conditions under different working load states. In different working modes, the two air channels are always in a normally open state, which can provide sufficient oxygen for combustion, and use air to cool the full premixed combustion, reduce the combustion temperature, and reduce the generation of nitrogen oxides. Semi-premixed combustion is used to compensate for the problem that the flame of the full premixed combustion is unstable during low load combustion, and it is easy to flash back and burn parts, so as to achieve the technical effect of stable combustion at full load, improve thermal efficiency, and effectively solve the problem that the full premixed combustion in the prior art has too high combustion temperature and is easy to generate nitrogen oxides under high load state, and is easy to flash back and flame out under low load state.

[0073] Furthermore, in this embodiment, the air outlet gap is annular and constitutes a first fire hole, and the second combustion hole 1022 constitutes a second fire hole, and the cross-sectional area of ​​the second fire hole is smaller than the cross-sectional area of ​​the first fire hole, that is, the cross-sectional area of ​​the second combustion hole 1022 is smaller than the cross-sectional area of ​​the air outlet gap. The volume of the first premixing chamber 201 is larger than the volume of the second premixing chamber 202. By setting fire holes and premixing chambers of different sizes, premixing chambers of different sizes can be selected according to different workload states for mixing gas and air, and fire holes of corresponding sizes can be used for combustion, thereby meeting different combustion conditions.

[0074] Optionally, the second premixing chamber 202 is at least partially disposed in the first premixing chamber 201 to facilitate communication between the second premixing chamber 202 and the second combustion hole 1022 .

[0075] In some embodiments, the combustion device has a high-load combustion mode and a low-load combustion mode; when the combustion device is in the high-load combustion mode, the first gas channel 42 is opened and the second gas channel 43 is closed, and the air transported through the first air channel 32 and the gas transported through the first gas channel 42 are premixed in the first premixing chamber 201, and then ejected from the air outlet gap and ignited, and the air transported through the second air channel 33 directly escapes from the second combustion hole 1022 to the combustion chamber 101; when the combustion device is in the low-load combustion mode, the first gas channel 42 is closed and the second gas channel 43 is opened, and the air transported through the second air channel 33 and the gas transported through the second gas channel 43 are premixed in the second premixing chamber 202, and then ejected from the second combustion hole 1022 and ignited, and the air transported through the first air channel 32 directly escapes from the air outlet gap to the combustion chamber 101.

[0076] In the above embodiment, when the heat load demand is large, the combustion device starts the high-load combustion mode, the first gas channel 42 is opened, and the second gas channel 43 is closed. The air from the first air channel 32 and the gas from the first gas channel 42 are premixed in the first premixing chamber 201, and then reach the combustion chamber 101 through the gap between the two combustion holes for combustion, thereby realizing full premixed combustion. The gas combustion is premixed with all the required air, the flame propagates quickly, and the combustion temperature is high. When used in water heaters, it can bring about faster and more heat exchange, high water heating capacity, higher heat exchange efficiency, and technical effects of saving gas. At the same time, the second air channel 33 will transport part of the air, which passes through the second premixing chamber 202 and escapes from the second combustion hole 1022 to the combustion chamber 101, thereby taking away part of the heat from the combustion environment, lowering the combustion temperature, reducing nitrogen oxides, and reducing the production of harmful substances. When the heat load demand is relatively small, the combustion device starts the low-load combustion mode, the second gas channel 43 is opened, and the first gas channel 42 is closed, the air in the second air channel 33 and the gas in the second gas channel 43 are premixed in the second premixing chamber 202, and then ejected from the second combustion hole 1022 for combustion, performing semi-premixed combustion. Under low-load conditions, the gas is partially premixed with the required air, and the gap between the first combustion hole 1021 and the second combustion hole 1022 continuously provides secondary air required for combustion, maintaining continuous and stable combustion in the combustion chamber 101, making the flame more stable and less prone to flameout and backfire. The use of semi-premixed combustion compensates for the problems of unstable flame during low-load combustion of full premixed combustion, easy backfire and burning of parts, and unstable heating.

[0077] In some embodiments, the gas proportioning valve 41 has a first gas outlet and a second gas outlet, and the second premixing chamber 202 has a gas inlet and an air inlet; one end of the first gas channel 42 is connected to the first gas outlet, and the other end is connected to the upstream position of the first air channel 32; one end of the second gas channel 43 is connected to the second gas outlet, and the other end is connected to the gas inlet; the fan 31 has a first air outlet 311 and a second air outlet 312, one end of the first air channel 32 is connected to the first air outlet 311, and the other end is connected to the first premixing chamber 201; one end of the second air channel 33 is connected to the second air outlet 312, and the other end is connected to the air inlet.

[0078] In the above embodiment, the gas proportion valve 41 can adopt a one-inlet and two-outlet structure, the inlet of the gas proportion valve 41 is connected to the air intake connector, and the air intake connector is connected to the gas channel in the user's home, and the two gas outlets of the gas proportion valve 41 are respectively connected to the first gas channel 42 and the second gas channel 43, and the gas ratio allocated to the first gas channel 42 and the second gas channel 43 can be adjusted by controlling the opening of the gas proportion valve 41. In addition, the first gas channel 42 is connected to the upstream position of the first air channel 32 to achieve its communication with the first premixing chamber 201, so that the gas can be mixed with the air in the first air channel 32 in advance in the first air channel 32 before entering the first premixing chamber 201, thereby extending the mixing path and mixing time of the gas and air, so that the gas and air can be mixed more fully.

[0079] In some embodiments, the fan 31 includes an impeller and a volute, the impeller is arranged in the volute, the volute includes a spiral portion and an air outlet portion extending along the tangential direction of the spiral portion, the port of the air outlet portion constitutes a first air outlet 311, and a second air outlet 312 is opened on the side wall of the air outlet portion.

[0080] In the above embodiment, the first air outlet 311 is formed by adopting the port of the air outlet portion, and the second air outlet 312 is opened on the side wall of the air outlet portion, so that the first air outlet 311 can provide a larger air volume, ensuring that sufficient oxygen can be provided for combustion in the high-load combustion mode, and can also effectively ensure that in the low-load combustion mode, the secondary oxygen supply for combustion is continuously provided, thereby maintaining the continuous and stable combustion in the combustion chamber 101 and avoiding the phenomenon of backfire and flameout.

[0081] Specifically, the first air outlet 311 is larger than the second air outlet 312. Most of the air drawn in by the fan 31 is discharged from the first air outlet 311 to the first air channel 32, and a small part is discharged from the second air outlet 312 to the second air channel 33. A connecting joint is provided at the second air outlet 312 to facilitate connection with the second gas channel 43. The second air channel 33, the first gas channel 42 and the second gas channel 43 are all tube structures, such as metal tubes, plastic tubes, hoses, etc. The first air channel 32 adopts a shell structure, which is not only convenient for it to be connected with the air outlet port of the fan 31 (that is, the first air outlet 311), but also has a larger ventilation volume.

[0082] In some embodiments, the first air channel 32 includes a connecting section 321 and a mixing section 322, the connecting section 321 is connected between the first air outlet 311 of the fan 31 and the mixing section 322; a gas inlet 3211 is provided on the side wall of one end of the connecting section 321 away from the mixing section 322, and the first gas channel 42 is connected between the gas inlet 3211 and the first gas outlet.

[0083] In the above embodiment, the first air channel 32 adopts the design of the connecting section 321 and the mixing section 322, which facilitates the connection with the first air outlet 311 while effectively ensuring the mixing effect of air and gas in the first air channel 32, and by opening the gas inlet 3211 at the end of the connecting section 321 away from the mixing section 322, the gas enters from the upstream of the first air channel 32, thereby extending the mixing path and mixing time of the gas and air, so that the gas and air can be fully mixed for full premixed combustion.

[0084] Specifically, the connecting section 321 is a hollow elbow structure, which is convenient for docking with the air outlet port of the fan 31. The mixing section 322 is a hollow cylindrical structure. The cylindrical mixing section 322 has a large diameter and a long path, which can fully mix the gas with a large amount of air for full premixed combustion.

[0085] Preferably, the connecting section 321 and the mixing section 322 are integrally formed to facilitate processing and simplify the assembly process.

[0086] Preferably, the first air channel 32 is provided with two half shells, which are butted against each other to form a circumferentially closed first air channel 32. By providing the first air channel 32 in a manner of splicing two parts together, demolding is more convenient.

[0087] Furthermore, the two half shells are connected and fixed by multiple screws arranged at intervals. The screw connection is not only firmly and stably fixed, but also convenient for disassembly and assembly. Preferably, a sealing structure is provided at the butt joint of the two half shells to ensure the sealing effect of the first air channel 32.

[0088] In some embodiments, a plurality of retaining ribs 3221 are arranged at intervals along the gas flow direction in the first air channel 32 ; the plurality of retaining ribs 3221 are alternately arranged on opposite sides of the first air channel 32 to form a serpentine airflow channel in the first air channel 32 .

[0089] In the above embodiment, by providing a plurality of baffles 3221 in the first air channel 32, a spoiler effect can be achieved, and by alternately arranging the plurality of baffles 3221 on opposite sides of the first air channel 32, a serpentine airflow channel can be formed in the first air channel 32, thereby further extending the flow path of the mixed gas in the first air channel 32, so that the gas and air can be fully mixed to perform fully premixed combustion.

[0090] Specifically, the retaining ribs 3221 are arranged in the mixing section 322, and a plurality of retaining ribs 3221 are arranged at intervals along the axial direction of the cylindrical mixing section 322, and are alternately arranged left and right, so that the mixed gas can flow along the serpentine air flow channel in the mixing section 322, further extending the flow path of the mixed gas in the first air channel 32. Since the mixing section 322 has a more regular shape than the connecting section 321, it is more convenient to process and manufacture the retaining ribs 3221. Preferably, the retaining ribs 3221 and the mixing section 322 are integrally formed.

[0091] In some embodiments, the burner 10 includes a first combustion plate 11 and a second combustion plate 12, and a plurality of first combustion holes 1021 are spaced apart on the first combustion plate 11; the second combustion plate 12 is arranged below the first combustion plate 11, and a plurality of combustion cores 120 are spaced apart on the second combustion plate 12, and second combustion holes 1022 are arranged in the combustion cores 120; the inner diameter of the first combustion hole 1021 is greater than the outer diameter of the combustion core 120, and the plurality of combustion cores 120 are arranged one by one in the plurality of first combustion holes 1021, and the outer periphery of the combustion core 120 and the inner periphery of the first combustion hole 1021 form an air outlet gap.

[0092] In the above embodiment, a plurality of first combustion holes 1021 are arranged on the first combustion plate 11, a plurality of combustion cores 120 are arranged at intervals on the second combustion plate 12, a second combustion hole 1022 is formed inside the combustion core 120, the aperture of the first combustion hole 1021 is larger than the maximum outer diameter of the combustion core 120, and the plurality of combustion cores 120 are correspondingly arranged in the plurality of first combustion holes 1021, so that the first combustion plate 11 and the second combustion plate 12 can be nested to form a combined combustion plate, and the first combustion holes 1021 and the combustion core 120 are nested to form a combined combustion plate. The gap formed by the first combustion hole 1021 and the second combustion hole 1022 constitutes two independent fire holes, one of which is used for ejecting the mixed combustion gas, and the other is used for ejecting air. Specifically, under high load conditions, the gap between the first combustion hole 1021 and the combustion core 120 is used to eject the mixed combustion gas, and the second combustion hole 1022 is used to eject the air. Under low load conditions, the gap between the first combustion hole 1021 and the combustion core 120 is used to eject the air, and the second combustion hole 1022 is used to eject the mixed combustion gas, so as to meet different heat load requirements.

[0093] In some embodiments, the premixing structure 20 includes a first premixing shell 21, which has a first premixing chamber 201 therein; the upper end of the first premixing shell 21 is open, and the lower end is connected to the first air channel 32; the burner 10 cover is arranged on the open end of the first premixing shell 21 so that the first premixing chamber 201 is connected to the air outlet gap.

[0094] In the above embodiment, the upper end of the first premixing shell 21 is designed to be open, so that the outlet area of ​​the first premixing chamber 201 can be increased, and the burner 10 is installed on the open end of the first premixing shell 21 to cover the first premixing chamber 201. The first premixing chamber 201 can be directly connected to the air outlet gap, which further simplifies the structure and ensures that the gas in the first premixing chamber 201 can escape from the air outlet gap more smoothly and efficiently.

[0095] Specifically, the shape of the open upper end of the first premix shell 21 matches the shape of the first combustion plate 11 and the second combustion plate 12, and the first premix shell 21 and the first air channel 32 are integrally formed. By arranging the first premix shell 21 and the first air channel 32 as an integral structure, the assembly steps of the two can be omitted. The first premix shell 21 also adopts a half-and-half split structure to facilitate demolding. Specifically, the first premix shell 21 and the first air channel 32 are an integral hollow shell structure, and the hollow shell structure is two half shells spliced ​​together. After the two half shells are butt-jointed, a closed first air channel 32 and a first premix chamber 201 can be formed.

[0096] In some embodiments, the premixing structure 20 also includes a second premixing shell 22, which has a second premixing chamber 202 therein, and the second premixing shell 22 is installed and fixed on the first premixing shell 21; the second combustion plate 12 includes a plurality of distribution strips 121 arranged at intervals, and each distribution strip 121 is respectively provided with a plurality of combustion cores 120 at intervals, and the distribution strip 121 has a distribution channel inside, and the distribution channel is connected to the second combustion hole 1022 in the combustion core 120; the ends of the same side of the plurality of distribution strips 121 are fixed on the second premixing shell 22, and each distribution channel is connected to the second premixing chamber 202.

[0097] In the above embodiment, the second combustion plate 12 adopts a design of multiple distribution strips 121 arranged at intervals, so that the gas in the first premixing chamber 201 can pass through the gap between two adjacent distribution strips 121, enter the air outlet gap between the first combustion hole 1021 and the second combustion hole 1022 and be discharged, thereby avoiding the problem that the gap between the first combustion hole 1021 and the second combustion hole 1022 is completely blocked by a whole closed plate structure, so that the gas in the first premixing chamber 201 cannot enter the gap between the first combustion hole 1021 and the second combustion hole 1022. In addition, by fixing the ends of the same side of the multiple distribution strips 121 on the second premixing shell 22, assembly is more convenient.

[0098] Of course, in order to ensure that the gaps between the first premixing chamber 201 and the first combustion holes 1021 and the second combustion holes 1022 can be connected, the second combustion plate 12 may also be hollowed out.

[0099] In this embodiment, the distribution strip 121 adopts a hollow pipeline, on which a plurality of second combustion holes 1022 are arranged at intervals. One end of the distribution strip 121 is provided with an opening and connected to the second premixing shell 22. The gas reaches the second premixing shell 22, enters the distribution channel through the opening, and then sprays out through the second combustion hole 1022. When burning under high load, the second gas channel 43 is closed, and the gas enters the first air channel 32 through the second gas channel 43 to be fully mixed with the air, and then passes through the second premixing chamber 202 to reach the combustion plate for combustion. When burning under low load, the first gas channel 42 is closed, and the gas enters the second premixing chamber 202 through the second gas channel 43. A small amount of air also reaches the second premixing chamber 202 through the second air channel 33, and is preliminarily mixed with the gas here, and then sprays out through the distribution channel and the second combustion hole 1022 for combustion. To be precise, the gas and air enter the second premixing chamber respectively and preliminarily contact to become mixed gas.

[0100] In an optional embodiment, a plurality of distribution strips 121 are connected to the second premix shell 22 by screws or are integrally formed. Exemplarily, a plurality of distribution strips 121 are integrally formed with the second premix shell 22, and the processing method is roughly as follows: first, the overall shape is machined, and then a channel is machined from one end of each distribution plate body to the other end, and then one end of the opening is sealed with a plug. Then, the core channel of each combustion core 120 is machined from top to bottom, and then the gas flow holes corresponding to the second premix shell 22 and each distribution channel are machined.

[0101] In an optional embodiment, the second combustion plate 12 also includes a fixing plate, and the ends of the same side of the multiple distribution strips 121 are fixed to the fixing plate. The fixing plate has a cavity connecting the distribution channel and the second premixing chamber 202. The fixing plate and the second premixing shell 22 can be fixed by screws or integrally formed. The setting of the fixing plate makes it easier to synchronously and efficiently assemble and fix the multiple distribution strips 121 to the second premixing shell 22, thereby improving the assembly efficiency.

[0102] In some preferred embodiments, the second premixing shell 22 is installed on a side of the first premixing shell 21 away from the first air channel 32 to avoid interfering with air intake. A mounting opening is provided on the first premixing shell 21, and the second premixing shell 22 is installed in the mounting opening. A sealing structure is provided between the peripheral wall of the second premixing shell 22 and the mounting opening. The gas inlet and the air inlet are provided on the bottom wall of the second premixing shell 22 and are located outside the first premixing shell 21 to facilitate connection with the second gas channel 43 and the second air channel 33.

[0103] Specifically, the second premixing shell 22 adopts a rectangular shell structure, the volume of the second premixing shell 22 is much smaller than the first premixing shell 21, the second premixing shell 22 provides a small mixing space, and the primary air for premixed combustion delivered by the second air channel 33 is also less, and the continuous combustion mainly relies on the secondary air delivered by the first air channel 32, thereby realizing partial premixed combustion. Optionally, the second premixing shell 22 includes a shell body and a lower end cover, the lower end of the shell body is open, and the lower end cover is detachably mounted and fixed at the lower end of the shell body.

[0104] In some embodiments, the combustion device further includes a cover 50, which is disposed outside the burner 10 to provide heat insulation and protection.

[0105] The specific structure and working principle of the combustion device provided in this embodiment are as follows:

[0106] The first combustion plate 11 is provided with a first combustion hole 1021; the second combustion plate 12 is provided with a gas distribution channel and a second combustion hole 1022; the aperture of the first combustion hole 1021 is larger than the maximum outer diameter of the second combustion hole 1022, and the two can be nested to form a combined combustion plate, and an air outlet gap is formed when nested. The combustion device also includes a first premixing chamber 201, a second premixing chamber 202, a first gas channel 42, a second gas channel 43, a first air channel 32, and a second air channel 33. The first air channel 32 is connected to the air outlet port of the fan 31, and the other end is connected to the first premixing chamber 201. The second air channel 33 is arranged downstream of the fan 31, and the other end is connected to the second premixing chamber 202. The first gas channel 42 is arranged downstream of the second air channel 33 and close to the entrance position of the air duct of the first air channel 32. One end of the first gas channel 42 is connected to the gas proportional valve 41, and the other end is connected to the upstream position of the air duct of the first air channel 32; one end of the second gas channel 43 is connected to the gas proportional valve 41, and the other end is connected to the gas inlet of the second premixing chamber 202. The first air channel 32 and the second air channel 33 remain normally open.

[0107] During high-load combustion, full premixed combustion is adopted, the fan 31 provides suction, the first gas channel 42 is opened, and the second gas channel 43 is closed. The gas is input through the first gas channel 42, mixed with the air in the air duct of the first air channel 32, passes through the first premixing chamber 201, reaches the upper surface of the combined combustion plate through the air outlet gap, and is ignited by an ignition needle to generate an electric spark, and burns in the combustion chamber 101. At the same time, the second air channel 33 will transport part of the air, which passes through the second premixing chamber 202, passes through the distribution channel, and escapes from the second combustion hole 1022 to the combustion chamber 101, which can take away part of the heat of the combustion environment, reduce the combustion temperature, reduce nitrogen oxides, and reduce the production of harmful substances.

[0108] During low-load combustion, semi-premixed combustion is adopted, the fan 31 provides suction, the first gas channel 42 is closed, and the second gas channel 43 is opened, the gas enters the second premixing chamber 202 through the second gas channel 43, and the air enters the second premixing chamber 202 through the second air channel 33 to provide primary air for combustion. The gas and the primary air are preliminarily mixed in the second premixing chamber 202, pass through the distribution channel and the second combustion hole 1022 to reach the upper surface of the combined combustion plate, and are ignited by the ignition needle to generate an electric spark and burn in the combustion chamber 101. At the same time, the air transported by the first air channel 32 passes through the first premixing chamber 201 and the combined gap of the combustion hole 102 to the upper surface of the combustion plate, providing secondary air for combustion to maintain the continuous combustion in the combustion chamber 101.

[0109] In this embodiment, the combustion plate is connected to the combustion chamber 101, and combustion is performed on the upper surface of the combustion plate and the combustion space in the combustion chamber 101. Specifically, the combustion space is formed by the upper surface of the combustion plate and the side panels of the combustion chamber 101. The pulse ignition needle is installed on the panel of the combustion chamber 101, and the gas needs to reach the upper surface of the combustion plate before it can be ignited by the ignition needle discharge.

[0110] According to an embodiment of the present utility model, on the other hand, a household appliance is provided, including any one of a wall-mounted boiler and a gas water heater, the household appliance including a housing and a combustion device of any one of the above embodiments, the combustion device being used for heating water.

[0111] Preferably, the household appliance is a gas water heater.

[0112] The combustion device provided by the utility model is an improvement on the combustion device of a full premixed gas water heater product. In addition to being applied to this product, it can also be applied to other product series that are common to the same principle, such as wall-mounted boilers, etc.

[0113] According to an embodiment of the present utility model, on the other hand, a control method for household electrical appliances applied to any of the above embodiments is provided, wherein the combustion device has a high-load combustion mode and a low-load combustion mode, and the control method comprises the following steps:

[0114] Step S101: receiving a preset water use instruction;

[0115] Step S102: Based on the water use instruction, analyzing and determining whether the water use temperature is greater than the set water temperature;

[0116] If yes, execute step S103; if no, execute step S104;

[0117] Step S103: Control the combustion device to start the high-load combustion mode:

[0118] The first gas channel 42 is controlled to be opened and the second gas channel 43 is controlled to be closed, and the air delivered through the first air channel 32 and the gas delivered through the first gas channel 42 are controlled to be premixed in the first premixing chamber 201, and then ejected from the air outlet gap, and ignited by the ignition mechanism, and burn in the combustion chamber 101 to heat the water temperature, and at the same time, the air delivered through the second air channel 33 is controlled to escape directly from the second combustion hole 1022 to the combustion chamber 101;

[0119] Step S104: Control the combustion device to start the low-load combustion mode:

[0120] The first gas channel 42 is controlled to be closed and the second gas channel 43 is controlled to be opened, and the air delivered through the second air channel 33 and the gas delivered through the second gas channel 43 are controlled to be premixed in the second premixing chamber 202, and then ejected from the second combustion hole 1022 and ignited by the ignition mechanism, and burn in the combustion chamber 101 to heat the water temperature. At the same time, the air delivered through the first air channel 32 is controlled to escape directly from the air outlet gap to the combustion chamber 101.

[0121] In the above embodiment, the high-load combustion mode adopts premixed combustion, and the low-load combustion mode adopts diffusion combustion. The combustion device is provided with two gas channels and two air channels. The corresponding gas channels are opened for combustion under high load and low load respectively. The two air channels are always open to provide oxygen required for combustion, thereby reducing the combustion temperature and achieving the technical effect of full-load stable combustion. The thermal efficiency of the water heater is greatly improved, and the problem of unstable low-load combustion of full premixed combustion in the prior art is solved.

[0122] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A combustion device, characterized in that: include: A burner (10), comprising a combustion chamber (101) and a plurality of groups of combustion holes (102) arranged at intervals in the combustion chamber (101), each group of combustion holes (102) comprising a first combustion hole (1021) and a second combustion hole (1022) located in the first combustion hole (1021); A premixing structure (20), wherein an air outlet gap is formed between the first combustion hole (1021) and the second combustion hole (1022), and the premixing structure (20) comprises a first premixing chamber (201) communicating with the air outlet gap, and a second premixing chamber (202) communicating with the second combustion hole (1022); An air inlet structure (30) comprising a fan (31), a first air passage (32) connected between the fan (31) and a first premixing chamber (201), and a second air passage (33) connected between the fan (31) and a second premixing chamber (202); A gas delivery structure (40) comprising a gas proportioning valve (41), a first gas passage (42) connected between the gas proportioning valve (41) and the first premixing chamber (201), and a second gas passage (43) connected between the gas proportioning valve (41) and the second premixing chamber (202); The opening area of ​​the air outlet gap is larger than the opening area of ​​the second combustion hole (1022), the first air channel (32) and the second air channel (33) are normally open, and the first gas channel (42) and the second gas channel (43) are selectively opened and closed.

2. The combustion device according to claim 1, characterized in that: The combustion device has a high-load combustion mode and a low-load combustion mode; When the combustion device is in a high-load combustion mode, the first gas channel (42) is opened and the second gas channel (43) is closed, the air transported through the first air channel (32) and the gas transported through the first gas channel (42) are premixed in the first premixing chamber (201), ejected from the air outlet gap and ignited, and the air transported through the second air channel (33) directly escapes from the second combustion hole (1022) to the combustion chamber (101); When the combustion device is in a low-load combustion mode, the first gas channel (42) is closed and the second gas channel (43) is opened; the air transported through the second air channel (33) and the gas transported through the second gas channel (43) are premixed in the second premixing chamber (202), ejected from the second combustion hole (1022) and ignited; the air transported through the first air channel (32) directly escapes from the air outlet gap to the combustion chamber (101).

3. The combustion device according to claim 1, characterized in that: The volume of the first premixing chamber (201) is greater than the volume of the second premixing chamber (202).

4. The combustion device according to any one of claims 1 to 3, characterized in that: The gas proportioning valve (41) has a first gas outlet and a second gas outlet, and the second premixing chamber (202) has a gas inlet and an air inlet; One end of the first gas channel (42) is connected to the first gas outlet, and the other end is connected to the upstream position of the first air channel (32); one end of the second gas channel (43) is connected to the second gas outlet, and the other end is connected to the gas inlet; The fan (31) has a first air outlet (311) and a second air outlet (312); one end of the first air channel (32) is connected to the first air outlet (311), and the other end is communicated with the first premixing chamber (201); one end of the second air channel (33) is connected to the second air outlet (312), and the other end is connected to the air inlet.

5. The combustion device according to claim 4, characterized in that: The fan (31) comprises: impeller; A volute, wherein the impeller is arranged in the volute, and the volute comprises a spiral portion and an air outlet portion extending in a tangential direction of the spiral portion; The port of the air outlet portion constitutes the first air outlet (311), and the second air outlet (312) is provided on the side wall of the air outlet portion.

6. The combustion device according to claim 4, characterized in that: The first air channel (32) comprises a connecting section (321) and a mixing section (322), wherein the connecting section (321) is connected between the first air outlet (311) of the fan (31) and the mixing section (322); A gas inlet (3211) is provided on a side wall of one end of the connecting section (321) away from the mixing section (322), and the first gas channel (42) is connected between the gas inlet (3211) and the first gas outlet.

7. The combustion device according to claim 4, characterized in that: A plurality of retaining ribs (3221) are arranged at intervals in the first air passage (32) along the gas flow direction; A plurality of retaining ribs (3221) are alternately arranged on opposite sides of the first air channel (32) to form a serpentine air flow channel in the first air channel (32).

8. The combustion device according to any one of claims 1 to 3, characterized in that: The burner (10) comprises: A first combustion plate (11) having a plurality of first combustion holes (1021) spaced apart from each other; A second combustion plate (12) is arranged below the first combustion plate (11), a plurality of combustion cores (120) are arranged at intervals on the second combustion plate (12), and the second combustion holes (1022) are arranged in the combustion cores (120); The inner diameter of the first combustion hole (1021) is larger than the outer diameter of the combustion core (120), and a plurality of the combustion cores (120) are arranged one by one in the plurality of the first combustion holes (1021), and the outer periphery of the combustion core (120) and the inner periphery of the first combustion hole (1021) form the air outlet gap.

9. The combustion device according to claim 8, characterized in that: The premixing structure (20) comprises: A first premixing shell (21) having the first premixing chamber (201) therein; the upper end of the first premixing shell (21) is open, and the lower end is connected to the first air channel (32); The burner (10) cover is arranged on the open end of the first premixing shell (21) so that the first premixing chamber (201) is in communication with the air outlet gap.

10. The combustion device according to claim 9, characterized in that: The premixing structure (20) further comprises: A second premixing shell (22) having the second premixing chamber (202) therein, and the second premixing shell (22) is mounted and fixed on the first premixing shell (21); The second combustion plate (12) comprises a plurality of distribution strips (121) arranged at intervals, each distribution strip (121) is provided with a plurality of combustion cores (120) at intervals, and a distribution channel is provided inside the distribution strip (121), and the distribution channel is communicated with the second combustion hole (1022) in the combustion core (120); The ends of the same side of the plurality of distribution strips (121) are fixed to the second premixing shell (22), and each of the distribution channels is communicated with the second premixing chamber (202).

11. A household appliance, comprising any one of a wall-mounted boiler and a gas water heater, characterized in that: The household electrical appliances include: shell; The combustion device according to any one of claims 1 to 10 is installed in the housing, and the combustion device is used to heat water.

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