Fully premixed combustion device and gas water heating equipment

Abstract

The utility model relates to the field of hot water supply equipment, and discloses a fully premixed combustion device and gas water heating equipment. The full-premixing combustion device comprises a fan, a premixer assembly, a first shell and a combustor. An air outlet of the fan is communicated with an air inlet end of the premixer assembly; a through hole is formed in one end of the first shell in the height direction of the first shell, and the other end of the first shell is open; the porous medium structure is arranged in the first shell and located between the through hole and the opening, and the first shell is divided by the porous medium structure to form a first premixing cavity; the combustor covers the opening and is fixedly connected with the first shell; and on the circulation path of the mixed gas, the mixed gas outlet end of the premixer assembly, the through hole, the first premixing cavity, a circulation channel in the porous medium structure and a combustion hole in the combustor are sequentially communicated. According to the porous medium structure, secondary uniform mixing is achieved through a pore network, it is guaranteed that heat loads on the surface of the combustor are uniform, and combustion stability is remarkably improved.

Description

Technical Field

[0001] This utility model relates to the technical field of hot water supply equipment, and in particular to a fully premixed combustion device and a gas-fired hot water equipment. Background Technology

[0002] For gas-fired hot water systems with fully premixed combustion, a fan draws air into the premixer assembly, where it is thoroughly mixed with the gas before being delivered to the burner for combustion. This design aims to improve combustion efficiency and reduce harmful emissions such as nitrogen oxides (NOx). x ).

[0003] However, traditional fully premixed combustion devices have some limitations and defects. For example, although the premixer can promote the initial mixing of air and gas, especially when clean energy is used, it has the characteristics of low ignition energy, easy ignition and fast combustion speed. Therefore, in actual operation, it is difficult to ensure uniform mixing of gas mixture by using only the premixer structure. This leads to incomplete combustion or overheating in local areas of the burner, resulting in backfire combustion and deflagration and other undesirable combustion conditions. Utility Model Content

[0004] The first technical problem solved by this invention is to provide a fully premixed combustion system, which effectively solves the problem of uneven gas mixing and unstable combustion in related technologies.

[0005] The second technical problem solved by this utility model is to provide a gas-fired hot water device that effectively solves the problem of uneven gas mixing and unstable combustion in related technologies.

[0006] The first technical problem mentioned above is solved by the following technical solution:

[0007] A fully premixed combustion device includes a fan, a premixer assembly, a first housing, and a burner;

[0008] The air outlet of the fan is connected to the air inlet of the premixer assembly; along the height direction of the first housing, one end of the first housing is provided with a through hole, and the other end is open; the porous medium structure is disposed inside the first housing and located between the through hole and the open end, and the porous medium structure divides the internal space of the first housing to form a first premixing cavity; the burner cover is disposed on the open end and is fixedly connected to the first housing; in the flow path of the mixed gas, the mixed gas outlet end of the premixer assembly, the through hole, the first premixing cavity, the flow channel in the porous medium structure and the combustion hole in the burner are connected in sequence.

[0009] Compared with the prior art, the fully premixed combustion device of this utility model has the following beneficial effects: (1) Through the three-stage mixing path of the premixer assembly, the first premixing chamber and the porous medium structure, the irregular pore network of the porous medium is used to enhance the mixing effect, making the mixed gas more uniform. At the same time, the pore distribution of the porous medium structure ensures that the mixed gas flow rate is evenly distributed to each combustion hole of the burner, ensuring that the mixed gas components are evenly distributed, eliminating local rich or lean combustion areas, reducing the occurrence of incomplete combustion or overheating in local areas of the burner, which leads to backfire and deflagration, and improving the stability of combustion. At the same time, the uniform combustion process reduces the generation of thermal nitrogen oxides, protects the burner structure from high temperature damage, and extends the service life of the equipment. (2) The high heat capacity and pore insulation characteristics of the porous medium structure can block the flame backfire propagation path. Even if the flame backfires into the inner cavity of the burner, it can effectively prevent it from continuing to spread upstream, eliminating safety hazards such as deflagration or detonation. It further reduces the occurrence of incomplete combustion or overheating in local areas of the burner, which leads to backfire and deflagration, and makes the combustion more stable.

[0010] In one embodiment, a limiting portion is provided inside the first housing, the outer peripheral wall of the porous medium structure abuts against the inner peripheral wall of the first housing, and one end of the porous medium structure adjacent to the first premixing cavity abuts against the limiting portion.

[0011] In one embodiment, the central axis of the through hole, the central axis of the first premixed cavity, and the central axis of the porous medium structure all coincide with each other.

[0012] In one embodiment, a second premixing chamber is formed between the porous media structure and the burner; in the flow path of the mixed gas, the mixed gas outlet end of the premixer assembly, the through hole, the first premixing chamber, the flow channel in the porous media structure, the second premixing chamber and the combustion hole in the burner are sequentially connected.

[0013] In one embodiment, the volume of the first premixing chamber is greater than the volume of the second premixing chamber.

[0014] In one embodiment, the porous medium structure is a porous medium plate with irregular pores.

[0015] In one embodiment, a second housing is further included, the second housing having a combustion chamber; in the flow path of the mixture, the second housing is installed downstream of the burner and fixedly connected to the burner, and the outlet end of the combustion hole communicates with the combustion chamber inside the second housing;

[0016] The burner has an integrally formed combustion hole and a cooling channel. The combustion hole extends through both ends of the burner along its height direction. The cooling channel surrounds the combustion hole. The burner is also equipped with a water inlet connector and a water outlet connector, which are respectively connected to both ends of the cooling channel.

[0017] In one embodiment, the burner is provided with a plurality of sets of combustion holes, each set of combustion holes including multiple combustion holes; the cooling channel is arranged around at least one set of combustion holes.

[0018] In one embodiment, the cooling channel includes at least two parallel first channels extending along the length of the burner, with a set of combustion holes sandwiched between every two adjacent first channels; the cooling channel also includes a plurality of second channels extending along the width of the burner, with every two adjacent first channels connected through the second channels.

[0019] And / or, the thickness of the burner is in the range of 3mm to 10mm.

[0020] The second technical problem mentioned above is solved by the following technical solution:

[0021] A gas-fired water heater includes a fully premixed combustion device as described in the first aspect of the present invention; it also includes a water heater housing, wherein the fully premixed combustion device is installed inside the water heater housing.

[0022] Compared with the prior art, the gas-fired hot water equipment of this utility model has the following beneficial effects: (1) The porous medium structure in the first shell forces the mixed gas to achieve secondary mixing in the flow channel through the pore network, and the mixed gas is more uniformly mixed. Its pore distribution characteristics evenly distribute the mixed gas flow rate to each combustion hole of the burner, eliminate local rich or lean combustion areas, reduce the occurrence of incomplete combustion or overheating in local areas of the burner, which leads to backfire combustion and deflagration, improve the stability of combustion, and reduce the risk of thermal stress concentration and equipment damage. (2) The high heat capacity and pore barrier characteristics of the porous medium structure form a thermal barrier. When the flame flows back to the porous medium, the heat in its pores is quickly absorbed and dispersed, the flame propagation rate is greatly reduced, the flame front is divided into multiple segments, and it cannot continue to propagate back to the premixing chamber or fuel end, thereby completely blocking the backfire path and eliminating safety hazards. (3) The porous medium structure reduces the temperature peak of the combustion area by evenly distributing the mixed gas flow rate and absorbing local heat. The uniform combustion process reduces the generation of thermal nitrogen oxides and protects the burner structure from high temperature damage, extending the service life of the equipment. (4) Through the physical properties (pore network and heat capacity) of the porous media structure, mixing enhancement, flow distribution and flame arrest functions are achieved without the need for additional sensors or control devices. The structure is compact and easy to integrate into existing combustion systems, reducing manufacturing and maintenance costs. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of the fully premixed combustion device according to an embodiment of the present invention;

[0025] Figure 2 This is a cross-sectional view of the fully premixed combustion device according to an embodiment of the present invention;

[0026] Figure 3 This is an explosion diagram of the fully premixed combustion device according to an embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the burner structure according to an embodiment of the present invention;

[0028] Figure 5 This is a cross-sectional view of a burner according to an embodiment of the present invention;

[0029] Figure 6This is one of the cross-sectional views of a burner according to another embodiment of the present invention;

[0030] Figure 7 This is a second cross-sectional view of a burner according to another embodiment of the present invention.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Fan; 2. Premixer assembly; 21. Premixer; 22. Solenoid valve; 23. Solenoid valve sealing ring; 24. First premixer sealing ring; 25. Second premixer sealing ring; 3. First housing; 31. First premixing chamber; 32. Through hole; 33. Limiting part; 34. First sealing ring;

[0033] 4. Burner; 41. Combustion port; 42. Cooling channel; 421. First channel; 422. Second channel; 43. Second premixing chamber; 44. Water inlet connector; 45. Water outlet connector; 46. Sealing end plate; 5. Second housing; 51. Ignition feedback needle; 52. Ignition feedback needle sealing gasket; 53. Heat insulation cotton; 54. Heat insulation cotton pressure plate; 55. Second sealing ring; 6. Porous media structure. Detailed Implementation

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0036] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0037] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0038] The present invention provides a fully premixed combustion device and a gas-fired hot water equipment having the fully premixed combustion device, as described below with reference to the accompanying drawings.

[0039] like Figures 1 to 7 As shown, the fully premixed combustion device according to the first aspect of the present invention includes a fan 1, a premixer assembly 2, a first housing 3, and a burner 4.

[0040] The air outlet of fan 1 is connected to the air inlet of premixer assembly 2; along the height direction of the first housing 3 ( Figure 2 (As shown in the up-down direction), one end of the first housing 3 is provided with a through hole 32, and the other end is open; a porous medium structure 6 is provided inside the first housing 3 and located between the through hole 32 and the open end, and the porous medium structure 6 divides the internal space of the first housing 3 to form a first premixing cavity 31; the burner 4 is covered by the open end and fixedly connected to the first housing 3; in the flow path of the mixed gas, the mixed gas outlet end of the premixer assembly 2, the through hole 32, the first premixing cavity 31, the flow channel in the porous medium structure 6 and the combustion hole 41 in the burner 4 are connected in sequence.

[0041] The specific structure of the fully premixed combustion device according to an embodiment of this utility model is described below:

[0042] The outlet of the blower 1 is directly connected to the air inlet of the premixer assembly 2. The blower 1 ensures thorough mixing of air and fuel gas by providing a stable airflow. The outlet of the premixer assembly 2 is connected to the internal space of the first housing 3. The premixer assembly 2 is used to complete the initial mixing of air and fuel gas, forming a preliminary air-fuel mixture. The first housing 3 contains a first premixing chamber 31 and a porous media structure 6. The porous media structure 6 is fixed inside the first housing 3, forming the first premixing chamber 31 between itself and the outlet of the premixed gas. The first premixing chamber 31 serves as a buffer space before the premixed gas enters the porous media structure 6, initially distributing the premixed gas evenly. The porous media structure 6 further enhances the mixing effect through its irregular pore network, making the premixed gas more uniform and evenly distributing the premixed gas flow to the burner 4. The downstream end of the first housing 3 is open and fixedly connected to the burner 4, forming a continuous flow path for the premixed gas. The burner 4 achieves stable combustion of the premixed gas through the combustion holes 41.

[0043] Based on the above-described specific structure, the working principle of the fully premixed combustion device of this utility model is as follows:

[0044] The premixer assembly 2 completes the initial mixing of air and fuel gas, forming a preliminary air-fuel mixture. After entering the first premixing chamber 31, the mixture is guided by the through-hole 32 to initially eliminate deviations in the flow direction, balance the pressure distribution, and ensure the uniformity of the mixture at the porous medium inlet. The mixture then enters the irregular pore network of the porous medium structure 6. Due to the complex connectivity of the pores, the mixture continuously collides and disperses during flow, further homogenizing the mixing ratio. At the same time, the pore distribution characteristics of the porous medium ensure that the mixture is distributed to the combustion holes 41 of the burner 4 at a uniform flow rate, avoiding the formation of localized rich or lean combustion zones.

[0045] Therefore, through the dual mixing mechanism and uniform flow distribution, the heat intensity distribution on the surface of burner 4 is ensured to be uniform, reducing the risk of local overheating and minimizing the occurrence of incomplete combustion or overheating in local areas of burner 4, which could lead to flashback and deflagration. This also reduces the generation of harmful substances such as nitrogen oxides. Furthermore, the high heat capacity and porous structure of the porous media material can absorb heat and block the propagation of flame flashback. Even if the flame flashes back into the inner cavity of burner 4, the insulating properties of the porous media can prevent the flame from spreading further upstream, fundamentally eliminating the risk of deflagration or detonation caused by flashback.

[0046] Furthermore, the specific working process of the fully premixed combustion device of this utility model is as follows:

[0047] The blower 1 delivers air into the premixer assembly 2, where it mixes with the fuel gas in a set ratio to form a preliminary air-fuel mixture. The mixture enters the first housing 3 through the outlet of the premixer assembly 2, first passing through the through-hole 32 into the first premixing chamber 31. Within this space, the mixture is initially evenly distributed, and the pressure and flow rate tend to stabilize. The mixture flows from the first premixing chamber 31 into the irregular pore network of the porous media structure 6. The complex path of the pores forces the mixture to collide and disperse multiple times, further homogenizing the mixing ratio. Simultaneously, the pore distribution of the porous media ensures that the mixture flow rate is evenly distributed to the combustion holes 41 of the burner 4. The uniform mixture enters the combustion zone of the burner 4 through the combustion holes 41, achieving a stable and efficient combustion process. If flashback occurs, the heat insulation properties of the porous media structure 6 can absorb heat and block the flame propagation path, preventing flashback from spreading towards the premixer 21 or the blower 1.

[0048] In summary, this invention achieves uniform flow distribution and heat intensity distribution through a dual mixing mechanism of the premixer 21 and the porous medium, significantly improving the uniformity of air-fuel mixture, reducing incomplete combustion, and thus lowering the risk of localized overheating and eliminating deflagration caused by backfire. Furthermore, this invention reduces the formation of harmful substances such as nitrogen oxides through uniform flow distribution and stable combustion.

[0049] Furthermore, compared with related technologies, this utility model has at least the following advantages: (1) Through the three-stage mixing path of the premixer assembly 2, the first premixing chamber 31, and the porous medium structure 6, the irregular pore network of the porous medium is used to enhance the mixing effect, eliminate local rich or lean combustion areas, reduce the occurrence of incomplete combustion or overheating in local areas of the burner 4 leading to backfire and deflagration, and improve the stability of combustion; at the same time, the uniform distribution of the mixed gas leads to a uniform combustion process that reduces the generation of thermal nitrogen oxides, protects the structure of the burner 4 from high temperature damage, and extends the service life of the equipment. (2) The high heat capacity and pore insulation characteristics of the porous medium structure 6 can block the flame backfire propagation path. Even if the flame backfires into the inner cavity of the burner 4, it can effectively prevent it from continuing to spread upstream, eliminating safety hazards such as deflagration or detonation. It further reduces the occurrence of incomplete combustion or overheating in local areas of the burner leading to backfire and deflagration, and makes the combustion more stable.

[0050] like Figure 1 and Figure 3 As shown, according to some embodiments of this utility model, the premixer assembly 2 includes a premixer 21, a solenoid valve sealing ring 23, and a solenoid valve 22. It is mainly used to mix fuel and air in a scientific ratio to form a uniform combustible mixture, ensuring a more complete and stable combustion process, and achieving efficient combustion and energy-saving effects. The premixer 21 has an air inlet, a gas inlet, and a mixed gas outlet. The gas inlet is equipped with a solenoid valve 22 and a solenoid valve sealing ring 23. It can be understood that the solenoid valve sealing ring 23 is used to seal between the solenoid valve 22 and the premixer 21, while the solenoid valve 22 is used to cut off the gas supply.

[0051] like Figure 1 and Figure 3 As shown, furthermore, a first premixer sealing ring 24 is sandwiched between the air inlet end of the premixer 21 and the air outlet of the fan 1, and a second premixer sealing ring 25 is sandwiched between the mixed gas outlet end of the premixer 21 and the through hole 32 on the first housing 3. The above sealing structure can ensure the sealing performance of the premixer assembly 2.

[0052] like Figure 2As shown, according to some embodiments of the present invention, a limiting part 33 is provided inside the first housing 3. The limiting part 33 is located between the first premixing cavity 31 and the porous medium structure 6. The outer peripheral wall of the porous medium structure 6 abuts against the inner peripheral wall of the first housing 3, and one end of the porous medium structure 6 adjacent to the first premixing cavity 31 abuts against the limiting part 33.

[0053] In this embodiment, the limiting part 33 is located between the first premixing cavity 31 and the porous medium structure 6, and can serve as a positioning reference for the porous medium structure 6. The limiting part 33 prevents the porous medium structure 6 from moving towards the first premixing cavity 31 through physical contact. The axial position of the porous medium structure 6 is jointly constrained by the limiting part 33 and the open end of the first housing 3.

[0054] On the one hand, the outer peripheral wall of the porous media structure 6 is in close contact with the inner peripheral wall of the first housing 3, ensuring its stability in the circumferential direction and preventing displacement due to vibration or thermal expansion. On the other hand, the end of the porous media structure 6 adjacent to the first premixing cavity 31 directly abuts against the limiting part 33, restricting its axial movement. Therefore, the combination design of the limiting part 33 and the circumferential contact allows it to achieve both circumferential and axial positioning within the first housing 3, thereby ensuring the precise installation position of the porous media structure 6 in three-dimensional space and avoiding the influence of assembly deviations on the flow path of the mixed gas.

[0055] It should be noted that the porous media structure 6 may experience thermal expansion under high-temperature conditions. The axial abutment design of the limiting part 33, combined with the circumferential contact, allows for slight radial or axial expansion of the material while maintaining the overall structural stability. Furthermore, this structural design facilitates the disassembly and replacement of the porous media structure 6. Simply disconnecting the first housing 3 from the burner 4 allows the porous media structure 6 to be removed through the open end without damaging other components.

[0056] Thus, this embodiment, through the cooperative design of the limiting part 33 and the porous media structure 6, ensures the stable installation of the porous media structure 6 in three-dimensional space, preventing displacement during operation. Simultaneously, physical contact positioning reduces assembly complexity and improves maintainability. Furthermore, the above structure makes the porous media structure 6 easy to disassemble and replace.

[0057] For example, such as Figure 2As shown, the inner peripheral wall of the first housing 3 is stepped, thereby dividing the internal space of the first housing 3 into a smaller premixing cavity 31 and a larger mounting cavity. The upper part of the first premixing cavity 31 is connected to the through hole 32, and the lower part of the mounting cavity is the open end of the first housing 3. The porous medium structure 6 is installed in the mounting cavity. The stepped surface inside the first housing 3 forms a limiting part 33. The edge of the upper end face of the porous medium structure 6 abuts against the limiting part 33, and the outer peripheral wall of the porous medium structure 6 is in close contact with the inner peripheral wall of the mounting cavity.

[0058] It should be noted that the above embodiment is only one of the many embodiments of this utility model and does not constitute a specific limitation on the limiting part 33 in this utility model. In some other embodiments, the limiting part 33 may also be a limiting plate or other structure that protrudes from the inner wall surface of the first housing 3. This utility model does not make any special limitation here.

[0059] like Figure 2 As shown, the central axis of the through hole 32, the central axis of the first premixed cavity 31, and the central axis of the porous medium structure 6 all coincide with each other.

[0060] In this embodiment, the through-hole 32 is located at one end of the first housing 3 adjacent to the premixer assembly 2, and its geometric center completely coincides with the geometric center of the first premixing cavity 31. This ensures that the flow path of the mixed gas from the outlet of the premixer assembly 2 to the first premixing cavity 31 is not deviated. At this time, the symmetrical axis structure ensures that the mixed gas is initially uniformly distributed before entering the porous media structure 6, providing more stable initial conditions for enhanced mixing in the porous media. The axis of the porous media structure 6 coincides with the axis of the first premixing cavity 31, ensuring that the mixed gas maintains a consistent direction when flowing from the first premixing cavity 31 to the porous media structure 6. This further ensures that the mixed gas is uniformly distributed in the central region of the porous media structure 6. Combined with the pore network characteristics of the porous media, this further ensures that the heat intensity distribution of each combustion hole 41 of the burner 4 is uniform.

[0061] In this way, on the one hand, the coincident axis design eliminates local turbulence or eddies caused by eccentric flow, reducing pressure loss and energy loss of the mixture during the flow process. On the other hand, it ensures that the mixture is evenly distributed along the central axis, avoiding excessively high or low local flow rates caused by eccentric flow.

[0062] In addition, by strictly requiring axial alignment, the geometric consistency of the porous medium structure 6, the first premixed cavity 31 and the through hole 32 in space is ensured, reducing performance fluctuations caused by assembly deviations.

[0063] like Figure 2As shown, according to some embodiments of the present invention, a second premixing chamber 43 is formed between the porous media structure 6 and the burner 4; in the flow path of the mixed gas, the mixed gas outlet end of the premixer assembly 2, the through hole 32, the first premixing chamber 31, the flow channel in the porous media structure 6, the second premixing chamber 43 and the combustion hole 41 in the burner 4 are connected in sequence.

[0064] In this embodiment, the second premixing chamber 43 is located downstream of the porous media structure 6 and is directly opposite to the outlet of the flow channel of the porous media structure 6, forming an independent closed or semi-closed space. The outlet of the flow channel of the porous media structure 6 is directly connected to the second premixing chamber 43. After the mixed gas flows out from the pore network of the porous media, it first enters the second premixing chamber 43. The second premixing chamber 43 is directly connected to the inlet of the combustion hole 41, forming a continuous flow path of "porous media structure 6 → second premixing chamber 43 → combustion hole 41".

[0065] It is understandable that the second premixing chamber 43, as the final mixing and flow distribution area of ​​the gas mixture before entering the combustion port 41, can further optimize the mixing uniformity and ensure the flow consistency of each combustion port 41.

[0066] In this way, the second premixing chamber 43 acts as the final mixing barrier, ensuring that the composition and flow rate of the mixed gas reach their optimal state before entering the combustion orifice 41, reducing the risk of incomplete combustion or localized overheating. On the one hand, the volume design of the second premixing chamber 43 can further buffer the mixed gas flow, ensuring that it is evenly distributed to each combustion orifice 41 of the burner 4; on the other hand, through the uniform pressure distribution characteristics of the second premixing chamber 43, the mixed gas has reached a stable flow rate before entering the combustion orifice 41, avoiding uneven flow in the combustion orifice 41 due to flow fluctuations at the porous medium outlet.

[0067] In some embodiments of this invention, the second premixing chamber 43 may be formed only within the first housing 3, or only within the burner 4. Alternatively, the second premixing chamber 43 may be formed through a connection structure between the burner 4 and the first housing 3. This invention does not impose any particular limitation on this. For example, when the burner 4 is installed downstream of the first housing 3, a gap is formed between its front end and the end of the first housing 3, or the volume of the second premixing chamber 43 is achieved through a specific cavity structure inside the burner 4.

[0068] In one specific embodiment, the end of the burner 4 adjacent to the first housing 3 is open to form a semi-enclosed space, which is the second premixing chamber 43. For example, the upper end of the burner 4 is fixedly connected to the lower end of the first housing 3, and the upper end of the burner 4, the lower end of the first housing 3, and the porous media structure 6 together define the aforementioned second premixing chamber 43.

[0069] like Figure 2 As shown, the volume of the first premixing chamber 31 is greater than the volume of the second premixing chamber 43.

[0070] It is understandable that the volume of the first premixing chamber 31 is larger than the volume of the second premixing chamber 43, forming a volume gradient from large to small. The first premixing chamber 31, serving as a buffer and initial mixing space before the mixed gas enters the porous media structure 6, needs to provide a larger volume to accommodate the initial uniform distribution of the mixed gas. The second premixing chamber 43, as the final mixing and flow distribution area downstream of the porous media structure 6, has a smaller volume to quickly guide the mixed gas to the combustion orifice 41, avoiding a decrease in flow rate or pressure loss due to excessive volume.

[0071] In this way, the large-volume first premixing chamber 31 can buffer the initial pressure fluctuations of the mixture, ensuring a stable flow rate when entering the porous medium. The small-volume second premixing chamber 43, by limiting the space, forces the mixture to be evenly distributed to the combustion orifice 41 at a higher flow rate, avoiding a decrease in flow rate due to excessive volume, which would affect combustion efficiency. At the same time, the larger volume of the first premixing chamber 31 helps to disperse the initial temperature distribution of the mixture, while the compact design of the second premixing chamber 43 ensures that heat is homogenized before entering the combustion orifice 41. Thus, through the volume difference design, the first premixing chamber 31 undertakes the main mixing function, while the second premixing chamber 43 focuses on flow distribution, avoiding structural redundancy or functional overlap caused by equal volume.

[0072] like Figure 3 As shown, according to some embodiments of this utility model, the burner 4 is fixedly connected to the first housing 3, and a first sealing ring 34 is provided between them. In this way, the first sealing ring 34 can seal the gap between the burner 4 and the first housing 3, preventing the gas mixture from leaking out through the connection gap and ensuring the sealing effect of the overall device.

[0073] like Figure 2 and Figure 3 As shown, according to some embodiments of the present invention, the fully premixed combustion device further includes a second housing 5, which is provided with a combustion chamber; in the flow path of the mixed gas, the second housing 5 is installed downstream of the burner 4 and fixedly connected to the burner 4, and the gas outlet end of the combustion hole 41 is connected to the combustion chamber inside the second housing 5.

[0074] like Figure 3As shown, the fully premixed combustion device further includes an ignition feedback needle sealing gasket 52 and an ignition feedback needle 51, whose main function is to ignite the gas mixture. The ignition feedback needle 51 extends from the outside into the combustion chamber inside the second housing 5 and is sealed by the ignition feedback needle sealing gasket 52. It can be understood that the ignition feedback needle sealing gasket 52 is used to seal between the second housing 5 and the ignition feedback needle 51, while the ignition feedback needle 51 is used to release an electric arc to ignite the gas mixture and provide a flame feedback signal.

[0075] like Figure 2 and Figure 3 As shown, furthermore, a heat insulation cotton 53 is also provided inside the second housing 5. The heat insulation cotton 53 surrounds the combustion chamber inside the second housing 5, and the heat insulation cotton 53 is axially pressed and fixed inside the second housing 5 by a heat insulation cotton pressure plate 54. It can be understood that the heat insulation cotton 53 can isolate the transfer of heat from the combustion flame, thereby reducing heat loss and improving heat utilization efficiency.

[0076] like Figure 3 As shown, a second sealing ring 55 is further provided between the second housing 5 and the burner 4. In this way, the second sealing ring 55 can seal the gap between the burner 4 and the second housing 5, preventing the mixture from leaking out through the connection gap, and further ensuring the sealing effect of the overall device.

[0077] According to some embodiments of the present invention, the porous medium structure 6 is a porous medium plate with irregular pores.

[0078] In this embodiment, the porous medium structure 6 adopts a porous medium plate with irregular pores. The shape, size, distribution, and connectivity of the pores inside are all irregular. The complex interconnected paths of the pores form a non-directional fluid channel network, which can significantly enhance the turbulent dispersion effect of the gas mixture compared with regular pores. At the same time, the porous medium is implemented in a plate-like form, and its thickness, width, and height can be customized according to the specific requirements of the combustion device, while also meeting the requirement of a tight fit with the first shell 3.

[0079] Specifically, the plate-like structure is in close contact with the inner peripheral wall of the first housing 3 through the limiting part 33, ensuring that its position is fixed in the axial and circumferential directions. The flow channel of the porous medium plate is perfectly matched with the communication path of the first premixing chamber 31 and the second premixing chamber 43, and the mixed gas must pass through its irregular pore network before entering the downstream region.

[0080] It is understood that the random paths of the irregular pores in this embodiment can more uniformly disperse the components of the gas mixture. Simultaneously, the complex paths of the irregular pores can form a natural barrier to flame propagation. Furthermore, the pore size distribution of the irregular pores can reduce the risk of blockage by large particulate impurities, while turbulent flow facilitates the natural removal of impurities.

[0081] It should be noted that, in the field of wall-hung boilers or water heaters, the main types of fully premixed burners currently used include metal cylindrical burners, ceramic flat plate burners, and metal fiber burners. The fully premixed combustion method involves mixing the gas and air in a mixer before combustion. The mixture then burns rapidly and completely on the burner surface, resulting in high combustion efficiency, fast combustion speed, and a short flame. This effectively reduces the production of thermal nitrogen oxides, achieving a full, efficient, and environmentally friendly combustion process and reducing the emission of harmful gases.

[0082] In order to address the technical shortcomings of the aforementioned related technologies, such as Figures 4 to 7 As shown, the present invention has an integrally formed combustion hole 41 and cooling channel 42 inside the burner 4. The combustion hole 41 runs through both ends of the burner 4 along the height direction (up and down direction shown in the figure). The cooling channel 42 is arranged around the combustion hole 41. The burner 4 is also provided with a water inlet connector 44 and a water outlet connector 45, which are respectively connected to both ends of the cooling channel 42.

[0083] As described above, this invention features a water flow channel structure at the head of the burner 4, with the burner 4 head and the water flow channel structure being an integral unit. This ensures efficient heat conduction. By utilizing cold water flowing through the burner 4, the heat from the flame at the burner 4 head can be more effectively transferred to the water, thereby reducing the flame temperature and flame propagation rate, effectively preventing flame backfire, and further reducing the generation of thermal nitrogen oxides. Therefore, the above structure can overcome the technical defects existing in the aforementioned related technologies.

[0084] Specifically, in this embodiment, the combustion hole 41 and the cooling channel 42 are directly formed inside the burner body 4 through processes such as precision casting, machining, or 3D printing, forming a seamless connection structure. This eliminates assembly gaps, improves structural strength and sealing, and reduces the risk of leakage; at the same time, the cooling channel 42 surrounds the high-temperature area of ​​the combustion hole 41, ensuring efficient heat exchange.

[0085] The cooling channels 42 are distributed around or adjacent to the combustion holes 41, directly contacting the high-temperature area, thereby shortening the distance between the cooling water and the heat source, quickly absorbing heat, and preventing the burner 4 from overheating or deforming locally.

[0086] The inlet connector 44 and outlet connector 45 are respectively sealed to both ends of the cooling channel 42 to form a closed cooling water circulation path, thereby simplifying the cooling system design and supporting continuous heat dissipation; it is convenient to clean or replace the seals during maintenance without disassembling the burner 4 body.

[0087] Thus, this invention achieves a comprehensive advantage of efficient cooling, structural reliability, and simplified maintenance through the integrated molding design of the combustion hole 41 inside the burner 4 and the cooling channel 42, as well as the direct connection of the inlet / outlet water connectors 45. The adjacent layout of the cooling channel 42 ensures rapid heat dissipation, the integrated molding process improves durability, and the integrated connector design takes into account both manufacturing and maintenance convenience.

[0088] like Figures 4 to 6 As shown, in some embodiments of this utility model, the burner 4 is provided with a plurality of sets of combustion holes 41, each set of combustion holes 41 including multiple combustion holes 41; the cooling channel 42 is arranged around at least one set of combustion holes 41.

[0089] In this embodiment, the combustion holes 41 on the burner 4 are divided into several independent groups, each group containing multiple combustion holes 41. For example, they can be spatially distributed into inner ring groups, outer ring groups, or multi-region groups, with each group of combustion holes 41 sharing the cooling range of the same cooling channel 42. It is understood that the grouping design allows for independent control or localized thermal management of the combustion holes 41 in different regions, such as adjusting the gas flow rate or cooling intensity of each group to optimize combustion efficiency and temperature distribution.

[0090] At least one set of combustion holes 41 is surrounded by cooling channels 42, forming a ring-shaped or mesh-like cooling path. The orientation of the cooling channels 42 directly matches the distribution of the combustion hole group 41, and the path of the cooling channels 42 can be customized according to the shape of the combustion hole group 41. For example, a ring-shaped channel matches a circular combustion hole group 41, or a branched channel corresponds to multiple area groups. In this way, the surrounding cooling channels 42 can precisely dissipate heat to a specific combustion hole group 41, reduce heat conduction to other areas, and avoid local overheating or thermal stress concentration.

[0091] As described above, the grouped design allows for independent adjustment of the gas flow rate or air ratio of each group of combustion holes 41, for example, through grouped valve control, to adapt to different operating conditions. Meanwhile, the surrounding cooling channel 42 disperses heat stress concentration points, reducing the risk of localized deformation or cracking of the burner 4 and extending its service life. Furthermore, the cooperation between the grouped combustion holes 41 and the surrounding cooling channel 42 allows for localized enhanced cooling of high-temperature areas while reducing overcooling of other areas, thus balancing the overall heat load.

[0092] Furthermore, the layout of the combustion hole group 41 and the cooling channel 42 can be flexibly adjusted, for example, by increasing or decreasing the number of groups to adapt to different power requirements and improve the versatility of the design.

[0093] like Figure 4 or Figure 5As shown, in one specific embodiment, the cooling channel 42 includes at least two parallel first channels 421, which extend along the length of the burner 4, and a set of combustion holes 41 are sandwiched between every two adjacent first channels 421; the cooling channel 42 also includes a plurality of second channels 422, which extend along the width of the burner 4, and every two adjacent first channels 421 are connected through the second channels 422.

[0094] In this embodiment, at least two parallel first channels 421 extend along the length of the burner 4, forming a transverse cooling path. A set of combustion holes 41 is sandwiched between every two adjacent first channels 421, so that the cooling channels 42 are arranged tightly around the set of combustion holes 41, directly absorbing the heat generated. A second channel 422 is arranged along the width of the burner 4, connecting adjacent first channels 421 to form a complete cooling circuit. Thus, the first channels 421 and the second channels 422 together constitute a grid-like cooling network, ensuring uniform distribution and efficient circulation of cooling water within the burner 4. For example, cooling water can enter the first channel 421 from the inlet connector 44, diffuse longitudinally through the second channel 422 to other first channels 421, and finally be discharged through the outlet connector 45.

[0095] It can be understood that the overall cooling path of the cooling water is as follows: when the cooling water flows along the first channel 421, it absorbs the high temperature heat of the combustion hole group 41, and then it is laterally distributed to other areas through the second channel 422 to ensure that the cooling water covers all combustion holes 41 and avoids uneven cooling.

[0096] In summary, the first channel 421 covers the high-temperature area of ​​the combustion hole group 41 along its length, while the second channel 422 balances the cooling water flow along its width, ensuring a uniform temperature field across the burner 4 and preventing localized overheating or undercooling. The mesh-like cooling channel 42 can evenly distribute heat to all areas of the burner 4 body, reducing thermal stress concentration caused by localized high temperatures and improving the burner 4's resistance to deformation and its service life.

[0097] In addition, if a section of the first channel 421 becomes blocked or its cooling efficiency decreases, the second channel 422 can guide the cooling water to other paths through a longitudinal connection, maintaining some cooling function and reducing the risk of system failure.

[0098] Furthermore, the aforementioned layered mesh design supports flexible adjustments, such as increasing the number of first channels 421 to match the longer burner 4 length, or adjusting the density of second channels 422 to meet the needs of higher heat load areas.

[0099] According to some embodiments of this utility model, the thickness of the burner 4 ranges from 3mm to 10mm. Thus, by reasonably setting the thickness of the burner 4 head, sufficient mechanical strength can be ensured while maximizing the heat exchange area, adapting to the design requirements of different application scenarios.

[0100] like Figure 7 As shown, in some specific embodiments, the burner 4 is provided with a plurality of combustion holes 41 that are uniformly distributed and penetrate the burner 4 according to design requirements, and the combustion holes 41 are arranged in several groups. Cooling channels 42 are provided inside the burner 4 and are evenly distributed between each group of combustion holes 41. In addition, the outer edge of one end of the burner 4 adjacent to the first housing 3 protrudes towards the first housing 3, and a semi-enclosed second premixing chamber 43 is formed inside it. The second premixing chamber 43 is used to evenly distribute the gas mixture into each group of combustion holes 41.

[0101] like Figure 5 As shown, in some specific embodiments, the burner 4 is composed of a burner 4 plate and several sealing end plates 46. During the production process, the inside of the burner 4 plate is perforated to form a cooling channel 42. Then, the sealing end plates 46 are sealed to the end of the burner 4 plate to seal the cooling channel 42, thus finally obtaining a complete burner 4 structure. At the same time, the water outlet connector 45 and the water inlet connector 44 are both located at the same end of the burner 4 plate and are located on both sides of the sealing end plates 46 respectively.

[0102] The following is a specific embodiment of the fully premixed combustion device of this utility model.

[0103] like Figures 1 to 7 As shown, when the premixer assembly 2 is powered on, the gas flows into the internal mixing chamber of the premixer assembly 2 from the relevant set gas pipeline at a certain pressure and a certain flow rate. At the same time, the blower 1 starts running, and air enters through the air inlet of the blower 1 and flows out through the air outlet of the blower 1. At this time, the air enters the internal mixing chamber of the premixer assembly 2 through the air inlet end of the premixer assembly 2 and performs the first air-fuel mixture with the gas flowing into the internal mixing chamber of the premixer assembly 2 to form a mixed gas.

[0104] The mixed gas flows out from the mixed gas outlet end of the premixer assembly 2 and enters the first premixing space through the through hole 32 located in the middle of the top of the first housing 3. Then, through the pore structure of the porous medium structure 6, it undergoes a second air-fuel mixture to achieve a more uniform mixing state. Then, the mixed gas enters the second premixing space for mixed gas distribution, and then flows to the head surface of the burner 4 through the combustion hole 41 of the burner 4. Finally, it is ignited by the ignition feedback needle 51 located in the second housing 5, which releases an electric arc. The flue gas after combustion is discharged from the combustion chamber in the second housing 5.

[0105] Meanwhile, under certain pressure, water enters the cooling channel 42 inside the burner 4 through the water inlet connector 44 and finally flows out through the water outlet connector 45. The water flows evenly through the entire burner 4 according to the flow direction of the internal cooling channel 42, absorbing the heat at the head of the burner 4, thereby reducing the temperature of the burner 4 and the root of the flame, reducing the flame propagation rate, and preventing flame backfire. In addition, the head end of the burner 4 has a certain thickness H, so the combustion holes 41 have a certain length, which can further refine the flame temperature of each small gas through-hole, completely eliminating the flame backfire problem. At the same time, the reduction in flame temperature can also further reduce nitrogen oxide emissions.

[0106] In summary, the water-cooled fully premixed combustion method adopted in this invention ensures the stability of hydrogen-rich or pure hydrogen combustion, prevents deflagration or detonation caused by backfire, enhances the air-fuel premixing effect, and can effectively further reduce nitrogen oxide emissions. This enables more complete, efficient, environmentally friendly, and safe combustion when using hydrogen-rich or pure hydrogen energy sources.

[0107] like Figures 1 to 7 As shown, the gas-fired water heater according to the second aspect of the present invention includes a fully premixed combustion device as described in the first aspect of the present invention; it also includes a water heater housing, wherein the fully premixed combustion device is installed inside the water heater housing.

[0108] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0109] The specific embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A fully premixed combustion apparatus characterized by: The device comprises a fan (1), a premixer assembly (2), a first shell (3) and a burner (4). The air outlet of the fan (1) is in communication with the air inlet end of the premixer assembly (2); along the height direction of the first shell (3), one end of the first shell (3) is provided with a through hole (32), and the other end is provided with an opening; a porous medium structure (6) is arranged in the first shell (3) and located between the through hole (32) and the opening; the porous medium structure (6) divides the internal space of the first shell (3) into a first premixing cavity (31); the burner (4) is arranged on the opening and fixedly connected with the first shell (3); along the flow path of the mixed gas, the mixed gas outlet end of the premixer assembly (2), the through hole (32), the first premixing cavity (31), the flow channel in the porous medium structure (6) and the combustion hole (41) in the burner (4) are sequentially communicated.

2. The fully premixed combustion apparatus according to claim 1, characterized by: The first shell (3) is provided with a limiting portion (33), and the outer peripheral wall of the porous medium structure (6) abuts against the inner peripheral wall of the first shell (3); one end of the porous medium structure (6) adjacent to the first premixing cavity (31) abuts against the limiting portion (33).

3. The fully premixed combustion apparatus according to claim 2, characterized by: The central axis of the through hole (32), the central axis of the first premixing cavity (31) and the central axis of the porous medium structure (6) all coincide with each other.

4. The fully premixed combustion apparatus according to claim 1, characterized by: The second premixing cavity (43) is formed between the porous medium structure (6) and the burner (4); along the flow path of the mixed gas, the mixed gas outlet end of the premixer assembly (2), the through hole (32), the first premixing cavity (31), the flow channel in the porous medium structure (6), the second premixing cavity (43) and the combustion hole (41) in the burner (4) are sequentially communicated.

5. The fully premixed combustion apparatus according to claim 4, characterized by: The volume of the first premixing cavity (31) is greater than that of the second premixing cavity (43).

6. The fully premixed combustion apparatus according to any one of claims 1 to 5, characterized by: The porous medium structure (6) is a porous medium plate with irregular pores.

7. The fully premixed combustion apparatus according to any one of claims 1 to 5, characterized by: The device further comprises a second shell (5) provided with a combustion cavity; along the flow path of the mixed gas, the second shell (5) is arranged downstream of the burner (4) and fixedly connected with the burner (4); the gas outlet end of the combustion hole (41) is in communication with the combustion cavity; The burner (4) is integrally formed with a combustion hole (41) and a cooling channel (42); the combustion hole (41) penetrates through both ends of the burner (4) along the height direction of the burner (4); the cooling channel (42) is arranged around the combustion hole (41); the burner (4) is further provided with a water inlet connector (44) and a water outlet connector (45); the water inlet connector (44) and the water outlet connector (45) are respectively in communication with both ends of the cooling channel (42).

8. The fully premixed combustion apparatus according to claim 7, characterized by: The burner (4) is provided with a plurality of groups of combustion holes (41); each group of combustion holes (41) comprises a plurality of combustion holes (41); the cooling channel (42) is arranged around at least one group of combustion holes (41).

9. The fully premixed combustion apparatus according to claim 8, characterized by: The cooling channel (42) comprises at least two first channels (421) parallel to each other, the first channels (421) extending along the length direction of the burner (4), and a group of the combustion holes (41) is arranged between every two adjacent first channels (421); the cooling channel (42) further comprises a plurality of second channels (422), the second channels (422) extending along the width direction of the burner (4), and every two adjacent first channels (421) are communicated through the second channels (422); The thickness of the burner (4) is 3mm-10mm.

10. A gas water heating apparatus, characterised in that, The full-premix combustion device comprises a hot water equipment shell, and the full-premix combustion device is installed in the hot water equipment shell.

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