Combustion chamber shell and gas water heater

Abstract

The utility model discloses a combustion chamber casing and gas water heater relates to gas equipment technical field. Among them, the combustion chamber casing includes frame body, flexible heat insulation cotton and high temperature protection layer that endures, and the frame body inner chamber forms has the combustion chamber, flexible heat insulation cotton is located in the inner wall surface of frame body, and at least surrounds the around of combustion chamber, and high temperature protection layer that endures at least is located in the one side of flexible heat insulation cotton close to the combustion chamber. The utility model technical scheme can reduce the surface temperature of combustion chamber casing, improves the reliability of heat insulation layer simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of gas equipment, and in particular to a combustion chamber shell and a gas water heater. Background Technology

[0002] A gas water heater is a gas-fired device that uses gas as fuel and heats water by transferring heat to cold water flowing through a heat exchanger.

[0003] Since the gas burns in the combustion chamber, the shell temperature of the combustion chamber is relatively high. In order to prevent the high temperature heat energy of the combustion chamber from being transferred outward and damaging other components of the gas water heater, it is necessary to cool down the shell of the combustion chamber.

[0004] In related technologies, a heat insulation layer is installed on the inner wall of the combustion chamber shell to insulate and cool the equipment. However, when the equipment is subjected to collisions or drops during assembly, transportation or handling, the heat insulation layer is easily damaged or falls off, resulting in poor reliability. Utility Model Content

[0005] The main purpose of this invention is to provide a combustion chamber shell that aims to reduce the surface temperature of the combustion chamber shell while improving the reliability of the heat insulation layer.

[0006] To achieve the above objectives, the combustion chamber shell proposed in this utility model includes:

[0007] The frame has an internal cavity forming a combustion chamber;

[0008] Flexible thermal insulation cotton is disposed on the inner wall surface of the frame and at least surrounds the combustion chamber; and

[0009] A high-temperature resistant protective layer is provided at least on the side of the flexible heat insulation cotton closest to the combustion chamber.

[0010] In one embodiment of this application, the high-temperature resistant protective layer at least covers the surface of the flexible heat insulation cotton facing the combustion chamber.

[0011] In one embodiment of this application, the flexible heat insulation cotton is provided with the high-temperature resistant protective layer on both the surface near the combustion chamber and the surface away from the combustion chamber.

[0012] In one embodiment of this application, the high-temperature resistant protective layer has a plate-like structure;

[0013] The high-temperature resistant protective layer is at least one of ceramic fiber board, mica board, and calcium silicate board.

[0014] In one embodiment of this application, the high-temperature resistant protective layer has a mesh structure;

[0015] The mesh structure is a high-temperature resistant mesh fabric, or the mesh structure is a high-temperature resistant fiber thread structure arranged in a cross pattern.

[0016] In one embodiment of this application, the mesh structure is ceramic fiber or glass fiber.

[0017] In one embodiment of this application, the high-temperature resistant protective layer is a coating structure applied to the surface of the flexible thermal insulation cotton.

[0018] In one embodiment of this application, the high-temperature resistant protective layer has a temperature tolerance of not less than 800°C;

[0019] And / or, the thermal conductivity of the high-temperature resistant protective layer is not greater than 0.3 W / m·K;

[0020] And / or, the tensile strength of the high-temperature resistant protective layer is not less than 120 kPa.

[0021] In one embodiment of this application, the thickness h of the high-temperature resistant protective layer satisfies: 0.05mm≤h≤5mm.

[0022] In one embodiment of this application, the flexible thermal insulation cotton is silicate fiber, silica fiber, or glass fiber.

[0023] In one embodiment of this application, the frame includes a bottom frame and a cover plate disposed on the bottom frame. The cover plate and the bottom frame enclose the combustion chamber having openings at the top and bottom. The inner wall surface of the cover plate and the inner wall surface of the bottom frame are both provided with the flexible heat insulation cotton and the high-temperature resistant protective layer.

[0024] The bottom frame and / or the cover plate have a flange that bends toward the combustion chamber and a claw on the flange. The flange covers the edge of the corresponding flexible heat insulation cotton and the edge of the high-temperature resistant protective layer. The claw is engaged with the surface of the high-temperature resistant protective layer toward the combustion chamber.

[0025] To achieve the above objectives, this application also provides a gas water heater, including a burner, a heat exchanger, a fan, and the aforementioned combustion chamber shell, wherein the heat exchanger is disposed above the combustion chamber shell, and the burner is disposed below the combustion chamber shell;

[0026] The fan is located above the heat exchanger, or the fan is located below the burner.

[0027] In this invention, the combustion chamber shell incorporates flexible heat insulation cotton on its inner wall, surrounding the combustion chamber. When the gas water heater is operating normally, the flexible insulation cotton prevents heat transfer from the combustion chamber to the frame, reducing the frame's surface temperature and heat storage. Consequently, when the gas water heater stops supplying water, the frame, with its lower heat storage, prevents excessive heat transfer to the heat exchanger, thus reducing the temperature rise during water outages. A high-temperature resistant protective layer is placed on the side of the flexible insulation cotton closest to the combustion chamber. This layer protects the surface of the flexible insulation cotton, enhancing its strength and preventing damage from impacts, thereby improving the assembly reliability of the flexible insulation cotton. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of one embodiment of the combustion chamber shell of this utility model;

[0030] Figure 2 This is a schematic diagram of the assembly structure of the bottom frame, flexible heat insulation cotton, and high-temperature resistant protective layer in an embodiment of this utility model;

[0031] Figure 3 for Figure 2 An exploded view of one embodiment of the structure;

[0032] Figure 4 This is a schematic diagram of the bottom frame structure in an embodiment of this utility model;

[0033] Figure 5 This is an exploded structural diagram of an embodiment of the cover plate, flexible heat insulation cotton, and high-temperature resistant protective layer of this utility model;

[0034] Figure 6 A schematic diagram of an embodiment in which a high-temperature resistant protective layer is provided on one side of the flexible thermal insulation cotton in this utility model;

[0035] Figure 7 A schematic diagram of an embodiment in which a high-temperature resistant protective layer is provided on opposite sides of the flexible heat insulation cotton in this utility model;

[0036] Figure 8 This is a schematic diagram of the assembly structure of the combustion chamber shell and the heat exchanger in an embodiment of this utility model;

[0037] Figure 9 for Figure 8 Explosion diagram of the embodiment;

[0038] Figure 10 This is a partial structural schematic diagram of an embodiment of the gas water heater of this utility model.

[0039] Explanation of icon numbers:

[0040]

[0041]

[0042] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0043] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0044] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0045] Meanwhile, the meaning of "and / or" or "and / or" appearing throughout the text is that it includes three options. Taking "A and / or B" as an example, it includes option A, option B, or an option that satisfies both A and B.

[0046] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0047] Gas burns in the combustion chamber, which has a high shell temperature. To prevent the high-temperature heat from the combustion chamber from transferring outwards and damaging other components of the gas water heater, the combustion chamber shell needs to be cooled down. Simultaneously, when the user turns off the water, the water in the heat exchanger stops flowing. The heat accumulated in the combustion chamber shell and heat exchanger fins due to heat transfer is conducted to the stagnant water in the heat exchanger, causing the water temperature to rise. When the user turns the water back on, the abnormally heated water flows through the pipes to the user's water outlet, causing a scalding sensation – this is the problem of temperature rise during water outage. Related technologies use an insulation layer on the inner wall of the combustion chamber shell to reduce heat and improve the temperature rise problem during water outage. However, during assembly, transportation, or handling, collisions or drops can easily damage the insulation layer, causing it to become snagged or detach from the combustion chamber shell.

[0048] Therefore, this utility model proposes a combustion chamber shell for use in gas water heaters, aiming to reduce the surface temperature of the combustion chamber shell and the temperature rise during water outages, while protecting the insulation cotton and improving the assembly reliability of the insulation cotton. It is understood that... Figures 8 to 10 The gas water heater includes a combustion chamber shell, a heat exchanger 3, a burner 4, and a fan 5. The combustion chamber shell forms a vertically connected combustion chamber. The heat exchanger 3 is located above the combustion chamber shell, and the burner 4 is located below it. The burner 4 is responsible for ignition and combustion. The combustion chamber provides the space for the combustion of gas and air. After the gas and air mix and burn, the resulting high-temperature flue gas flows upward to the heat exchanger 3 to heat the components to be heated (such as water pipes). The fan 5 drives the gas and air into the combustion chamber for combustion and transports the high-temperature flue gas after combustion to the heat exchanger 3 for heat exchange, then discharges the heat-exchanged exhaust gas. The structure of this combustion chamber shell is described below using an embodiment.

[0049] In the embodiments of this utility model, such as Figures 1 to 5 As shown, the combustion chamber shell includes a frame 1, flexible heat insulation cotton 21, and a high-temperature resistant protective layer 22.

[0050] The inner cavity of the frame 1 forms a combustion chamber; flexible heat insulation cotton 21 is provided on the inner wall surface of the frame 1 and at least surrounds the combustion chamber; a high-temperature resistant protective layer 22 is provided at least on the side of the flexible heat insulation cotton 21 near the combustion chamber.

[0051] In this embodiment, the inner cavity of the frame 1 forms a combustion chamber. Flexible heat insulation cotton 21 is installed on the inner wall of the frame 1, surrounding the combustion chamber. This flexible heat insulation cotton 21 isolates the high-temperature flue gas from the frame 1, preventing heat from the combustion chamber from being transferred to the frame 1, thus reducing the surface temperature of the frame 1. Simultaneously, the flexible heat insulation cotton 21 prevents heat transfer to the frame 1, reducing the heat storage capacity of the frame 1. Therefore, when the user stops using water, the frame 1, with its lower heat storage capacity, will not transfer excessive heat to the heat exchanger 3 to heat the stagnant water, effectively improving the problem of temperature rise during water outages.

[0052] It should be noted that in this embodiment, flexible heat insulation cotton 21 is provided on the inner wall of the frame 1. This flexible heat insulation cotton 21 is flexible and heat-insulating. Compared with the heat insulation method of using heat insulation cotton board (usually heat insulation materials are glued together to form a board) in related technologies, the flexible heat insulation cotton 21 in this embodiment has a lower density, and its flexible, cotton-like and fluffy properties can also play a role in buffering and sound absorption, achieving a noise reduction effect without the need for additional vibration damping structures. On the other hand, compared with the air-cooling method used in related technologies, this structure uses flexible heat insulation cotton 21 to isolate heat inside the combustion chamber, improving heat utilization efficiency. No additional cooling air is needed. Therefore, under the same heat demand, the required air volume of the fan 5 in this embodiment is lower, and the fan speed of the fan 5 is reduced, thereby reducing noise from the vibration source. Thus, this embodiment can reduce vibration source noise on the one hand, and absorb sound along the sound propagation path on the other hand, achieving a better noise reduction effect. Optionally, the flexible thermal insulation cotton 21 can be made of glass fiber thermal insulation cotton, mineral wool thermal insulation cotton, polyester thermal insulation cotton, ceramic fiber thermal insulation cotton, silicate thermal insulation cotton, silica thermal insulation cotton, or other materials.

[0053] However, in practical applications, because the surface of the flexible insulation cotton 21 is fluffy like cotton, during the assembly of the gas water heater, the flexible insulation cotton 21 on the inner wall of the frame 1 may collide with other components, easily causing damage or snagging, or it may be damaged by collision or drop during equipment transportation or handling. Based on this, this embodiment provides a high-temperature resistant protective layer 22 on the side of the flexible insulation cotton 21 near the combustion chamber. This high-temperature resistant protective layer 22 can protect the surface of the flexible insulation cotton 21, enhance the strength of the flexible insulation cotton 21, effectively prevent the surface of the flexible insulation cotton 21 from being damaged by collision with other components, and improve the assembly reliability of the flexible insulation cotton 21.

[0054] The high-temperature resistant protective layer 22 is at least located on the side of the flexible insulation cotton 21 closest to the combustion chamber. It can be understood that the high-temperature resistant protective layer 22 can partially cover the flame side of the flexible insulation cotton 21, or it can completely cover the flame side of the flexible insulation cotton 21. Alternatively, the high-temperature resistant protective layer 22 can be located on other surfaces of the flexible insulation cotton 21 besides the flame side surface, such as the surface of the flexible insulation cotton 21 near the inner wall of the frame 1. In practical applications, the specific structure of the high-temperature resistant protective layer 22 can be determined according to the actual situation. For example, it can be a plate structure, membrane structure, sheet structure, mesh structure, coating structure, or some other type of structure. The specific material of the high-temperature resistant protective layer 22 can also be determined according to the actual situation. For example, it can be a high-temperature resistant coating, ceramic fiber material, mica board, calcium silicate board, etc., as long as it can protect the flexible insulation cotton 21.

[0055] In summary, the combustion chamber shell of this utility model incorporates flexible heat insulation cotton 21 on the inner wall of the frame 1. This flexible heat insulation cotton 21 surrounds the combustion chamber, preventing heat transfer from the combustion chamber to the frame 1 during normal operation of the gas water heater. This reduces the surface temperature of the frame 1 and decreases its heat storage capacity. Consequently, when the gas water heater stops discharging water, the frame 1, with its lower heat storage capacity, will not transfer excessive heat to the heat exchanger 3 to heat the stagnant water, effectively mitigating the temperature rise during water outages. A high-temperature resistant protective layer 22 is provided on the side of the flexible heat insulation cotton 21 closest to the combustion chamber. This high-temperature resistant protective layer 22 protects the surface of the flexible heat insulation cotton 21, enhancing its strength and effectively preventing damage from impacts, thus improving the assembly reliability of the flexible heat insulation cotton 21.

[0056] To further improve the structural reliability of the flexible thermal insulation cotton 21, in one embodiment of this application, such as Figure 2 , Figures 5 to 7 The high-temperature resistant protective layer 22 covers at least the surface of the flexible heat insulation cotton 21 facing the combustion chamber.

[0057] Understandably, since the flexible heat insulation cotton 21 is installed on the inner wall of the frame 1, the surface of the flexible heat insulation cotton 21 facing the combustion chamber is exposed. When other components such as heat exchangers and burners 4 are assembled onto the combustion chamber shell, they may rub against the surface of the flexible heat insulation cotton 21 facing the combustion chamber. In other words, the surface of the flexible heat insulation cotton 21 facing the combustion chamber is more prone to damage than other surfaces. Based on this, in this embodiment, the high-temperature resistant protective layer 22 covers at least the surface of the flexible heat insulation cotton 21 facing the combustion chamber, so that the surface of the flexible heat insulation cotton 21 facing the combustion chamber can be effectively protected by the high-temperature resistant protective layer 22, thereby improving the structural reliability of the flexible heat insulation cotton 21.

[0058] It should be noted that, in this embodiment, the high-temperature resistant protective layer 22 covering the surface of the flexible heat insulation cotton 21 facing the combustion chamber can mean that the high-temperature resistant protective layer 22 completely covers the surface of the flexible heat insulation cotton 21 facing the combustion chamber. In this case, the high-temperature resistant protective layer 22 can be understood as a fully enclosed structure (without through holes or gaps), such as a plate structure or sheet structure. Alternatively, the high-temperature resistant protective layer 22 itself can be a structure with through holes or gaps covering the surface of the flexible heat insulation cotton 21 facing the combustion chamber.

[0059] Furthermore, such as Figure 7 The flexible heat insulation cotton 21 has a high-temperature resistant protective layer 22 on both the surface near the combustion chamber and the surface away from the combustion chamber.

[0060] In this embodiment, by providing high-temperature resistant protective layers 22 on both sides of the flexible thermal insulation cotton 21, the flexible thermal insulation cotton 21 is sandwiched between the high-temperature resistant protective layers 22 on both sides, which further enhances the strengthening effect of the flexible thermal insulation cotton 21.

[0061] In one embodiment of this application, the high-temperature resistant protective layer 22 has a temperature resistance of not less than 800°C.

[0062] Since the high-temperature resistant protective layer 22 is located on the side of the flexible heat insulation cotton 21 near the combustion chamber, that is, the high-temperature resistant protective layer 22 is located on the side near the flame, the high-temperature resistant protective layer 22 in this embodiment has a temperature resistance of not less than 800℃ to ensure the reliability of the high-temperature resistant protective layer 22, thereby achieving the protective effect on the flexible heat insulation cotton 21.

[0063] In one embodiment of this application, the thermal conductivity of the high-temperature resistant protective layer 22 is no greater than 0.3 W / m·K.

[0064] This configuration ensures the overall heat insulation effect of the high-temperature resistant protective layer 22 and the flexible heat insulation cotton 21, prevents heat from being transferred to the frame 1, avoids overheating of the combustion chamber wall, and reduces the temperature rise during water outages.

[0065] In one embodiment of this application, the tensile strength of the high-temperature resistant protective layer 22 is not less than 120 kPa.

[0066] This design allows the high-temperature resistant protective layer 22 to provide better protection for the flexible thermal insulation cotton 21, preventing it from being damaged by collisions or snagged during assembly or transportation.

[0067] In one embodiment of this application, the thickness h of the high-temperature resistant protective layer 22 satisfies: 0.05mm≤h≤5mm.

[0068] Understandably, the thickness of the high-temperature resistant protective layer 22 should not be too large or too small. If it is too large, the high-temperature resistant protective layer 22 will be too thick, which may lead to excessive heat storage; if it is too small, the high-temperature resistant protective layer 22 will be too thin, which may not provide good protection. Based on this, in this embodiment, the thickness h of the high-temperature resistant protective layer 22 is limited to 0.05mm ≤ h ≤ 5mm, ensuring good protection while reducing heat storage. Preferably, the thickness h of the high-temperature resistant protective layer 22 is 0.2mm ≤ h ≤ 2mm; more preferably, the thickness h of the high-temperature resistant protective layer 22 is 0.8mm ≤ h ≤ 1.2mm.

[0069] In practical applications, the specific structure of the high-temperature resistant protective layer 22 can be determined according to the actual situation:

[0070] In one embodiment, such as Figure 6 and Figure 7 The high-temperature resistant protective layer 22 has a plate-like structure. This design provides better protection for the flexible insulation cotton 21. Optionally, the plate-like high-temperature resistant protective layer 22 can be applied only to the surface of the flexible insulation cotton 21 near the combustion chamber, or it can be applied to both the surface of the flexible insulation cotton 21 near the combustion chamber and the surface away from the combustion chamber. Optionally, the plate-like high-temperature resistant protective layer 22 can be at least one of ceramic fiber board, mica board, and calcium silicate board.

[0071] In one embodiment, the high-temperature resistant protective layer 22 has a mesh structure. This design, while protecting the flexible insulation cotton 21, reduces the area of ​​the high-temperature resistant protective layer 22, thereby lowering its heat storage capacity. Optionally, the mesh structure can be a high-temperature resistant mesh fabric. In practical applications, the high-temperature resistant mesh fabric can be directly wrapped around the surface of the flexible insulation cotton 21. In this case, the high-temperature resistant mesh fabric can be ceramic fiber cloth or glass fiber cloth. Optionally, the mesh structure can be a structure of cross-arranged high-temperature resistant fiber threads. In practical applications, the high-temperature resistant fiber threads can be cross-woven and sewn onto the surface of the flexible insulation cotton 21. In this case, the high-temperature resistant fiber threads can be ceramic fiber threads or glass fiber threads.

[0072] In one embodiment, the high-temperature resistant protective layer 22 is a coating structure applied to the surface of the flexible thermal insulation cotton 21. In practical applications, the high-temperature resistant coating can be directly sprayed onto the surface of the flexible thermal insulation cotton 21, and after drying and hardening, a high-temperature resistant protective layer 22 is formed to enhance the protection of the flexible thermal insulation cotton 21.

[0073] In one embodiment of this application, as Figures 1 to 5 The frame 1 includes a bottom frame 11 and a cover plate 12 disposed on the bottom frame 11. The cover plate 12 and the bottom frame 11 enclose a combustion chamber with openings at the top and bottom. The inner wall of the cover plate 12 and the inner wall of the bottom frame 11 are both provided with flexible heat insulation cotton 21 and high temperature resistant protective layer 22.

[0074] This embodiment illustrates the structure of the frame 1. The bottom frame 11 is open at the top and bottom, for connecting the heat exchanger 3 and the burner 4, respectively. It is understood that the bottom frame 11 includes a back plate 111 and two side plates 112 located on opposite sides of the back plate 111. The connection between the two side plates 112 and the back plate 111 gives the bottom frame 11 a roughly "U"-shaped cross-section. By covering the opening with a cover plate 12, the "U"-shaped structure is roughly transformed into a "U"-shaped cross-section, thus forming a combustion chamber that is open at the top and bottom and closed on all sides. By providing flexible insulation cotton 21 and a high-temperature resistant protective layer 22 on both the inner wall of the cover plate 12 and the inner wall of the bottom frame 11, better heat insulation is achieved.

[0075] Optionally, the flexible heat insulation cotton 21 may include a first heat insulation cotton and a second heat insulation cotton. The first heat insulation cotton is disposed on the bottom frame 11, and the second heat insulation cotton is disposed on the cover plate 12. Correspondingly, the high-temperature resistant protective layer 22 may also include a first protective layer and a second protective layer. By setting the frame 1 as a separate structure of the bottom frame 11 and the cover plate 12, it is easier to assemble the first heat insulation cotton, the second heat insulation cotton, the first protective layer, and the second protective layer. In actual assembly, the first heat insulation cotton and the first protective layer can be fixed to the inner wall of the bottom frame 11 first, and the second heat insulation cotton and the second protective layer can be fixed to the inner wall of the cover plate 12 before the cover plate 12 is installed on the bottom frame 11. In this way, the inner wall of the combustion chamber can be surrounded by heat insulation cotton to ensure the heat insulation effect. Optionally, the cover plate 12 and the bottom frame 11 can be fixed by screws, riveting, or other fixing methods.

[0076] Furthermore, such as Figures 1 to 5 The bottom frame 11 and / or the cover plate 12 are provided with a flange 114 bent toward the combustion chamber and a claw 115 provided on the flange 114. The flange 114 covers the edge of the corresponding flexible heat insulation cotton 21 and the edge of the high temperature resistant protective layer 22. The claw 115 and the surface of the high temperature resistant protective layer 22 facing the combustion chamber are matched and limited.

[0077] Optionally, the periphery of the side plate 112 of the bottom frame 11 includes an upper edge, a front edge, and a lower edge. Flanges 114 are provided at the upper edge, front edge, and lower edge to support the edges of the flexible insulation cotton 21 and the high-temperature resistant protective layer 22 at the side plate 112. Claws 115 are then provided at the flanges 114 to hold the flexible insulation cotton 21 and the high-temperature resistant protective layer 22 in place, thus fixing the flexible insulation cotton 21 and the high-temperature resistant protective layer 22. Alternatively, flanges 114 and claws 115 can also be provided on the back plate 111 at positions corresponding to the edges of the flexible insulation cotton 21 and the high-temperature resistant protective layer 22 to limit and fix the flexible insulation cotton 21 and the high-temperature resistant protective layer 22 covering the back plate 111.

[0078] Optionally, the periphery of the cover plate 12 may also be provided with flanges 114 and claws 115 for supporting and fixing the flexible heat insulation cotton 21 and the high-temperature protective layer 22 installed on the inner wall of the cover plate 12.

[0079] This utility model also proposes a gas water heater, such as Figures 8 to 10 The gas water heater includes a burner 4, a heat exchanger 3, a fan 5, and a combustion chamber shell. The specific structure of the combustion chamber shell is as described in the above embodiments. Since this gas water heater adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here. Among them, the heat exchanger 3 is located above the combustion chamber shell, and the burner 4 is located below the combustion chamber shell.

[0080] Understandably, this gas water heater can be a forced-draft type, in which the fan 5 is located above the heat exchanger 3 and drives the airflow through negative pressure suction; or it can be a blower type, in which the fan 5 is located below the burner 4 and drives the airflow through blowing air.

[0081] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A combustion chamber shell, characterized in that, include: The frame has an internal cavity forming a combustion chamber; Flexible heat insulation cotton is provided on the inner wall surface of the frame and at least surrounds the combustion chamber; as well as A high-temperature resistant protective layer is provided at least on the side of the flexible heat insulation cotton closest to the combustion chamber.

2. The combustion chamber shell as described in claim 1, characterized in that, The high-temperature resistant protective layer at least covers the surface of the flexible heat insulation cotton facing the combustion chamber.

3. The combustion chamber shell as described in claim 2, characterized in that, The flexible heat insulation cotton is provided with a high-temperature resistant protective layer on both the surface near the combustion chamber and the surface away from the combustion chamber.

4. The combustion chamber shell as described in any one of claims 1 to 3, characterized in that, The high-temperature resistant protective layer has a plate-like structure; The high-temperature resistant protective layer is at least one of ceramic fiber board, mica board, and calcium silicate board.

5. The combustion chamber shell as described in any one of claims 1 to 3, characterized in that, The high-temperature resistant protective layer has a mesh structure; The mesh structure is a high-temperature resistant mesh fabric, or the mesh structure is a high-temperature resistant fiber thread structure arranged in a cross pattern.

6. The combustion chamber shell as described in claim 5, characterized in that, The mesh structure is made of ceramic fiber or glass fiber.

7. The combustion chamber shell as described in any one of claims 1 to 3, characterized in that, The high-temperature resistant protective layer is a coating structure applied to the surface of the flexible thermal insulation cotton.

8. The combustion chamber shell as described in any one of claims 1 to 3, characterized in that, The high-temperature resistant protective layer has a temperature resistance of not less than 800℃; And / or, the thermal conductivity of the high-temperature resistant protective layer is not greater than 0.3 W / m·K; And / or, the tensile strength of the high-temperature resistant protective layer is not less than 120 kPa.

9. The combustion chamber shell as described in any one of claims 1 to 3, characterized in that, The thickness h of the high-temperature resistant protective layer satisfies: 0.05mm≤h≤5mm.

10. The combustion chamber housing according to any one of claims 1 to 3, characterized in that, The flexible thermal insulation cotton is made of silicate fiber, silica fiber, or glass fiber.

11. The combustion chamber shell as described in any one of claims 1 to 3, characterized in that, The frame includes a bottom frame and a cover plate disposed on the bottom frame. The cover plate and the bottom frame enclose the combustion chamber with openings at the top and bottom. The inner wall of the cover plate and the inner wall of the bottom frame are both provided with the flexible heat insulation cotton and the high-temperature resistant protective layer. The bottom frame and / or the cover plate have a flange that bends toward the combustion chamber and a claw on the flange. The flange covers the edge of the corresponding flexible heat insulation cotton and the edge of the high-temperature resistant protective layer. The claw is engaged with the surface of the high-temperature resistant protective layer toward the combustion chamber.

12. A gas-fired water heater, characterized in that, It includes a burner, a heat exchanger, a fan, and a combustion chamber housing as described in any one of claims 1 to 11, wherein the heat exchanger is disposed above the combustion chamber housing and the burner is disposed below the combustion chamber housing; The fan is located above the heat exchanger, or the fan is located below the burner.

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