CN116928668A - Porous medium burner - Google Patents

Abstract

The application is suitable for the technical field of combustors, and discloses a porous medium combustor which is applied to a water heater. The shell comprises a mixing cavity and a combustion chamber communicated with the mixing cavity; the porous medium body is arranged in the combustion chamber, is wavy and is provided with a plurality of pores; the air supply device is communicated with the mixing cavity and is used for providing combustion gas. Through setting up porous dielectric body in the combustion chamber, improve combustion efficiency, be favorable to promoting the rate of heating up of combustion chamber, in addition, porous dielectric body is the wave for the combustion chamber is heated evenly when working in the combustor. Meanwhile, the heat insulation component is arranged, so that the temperature of the combustion chamber can be prevented from radiating outwards, devices outside the combustion chamber can be protected, the temperature of the combustion chamber can be prevented from falling too fast, the porous medium body is prevented from being burst, and the service life of the porous medium body is prolonged.

Description

Porous medium burner

Technical Field

The application relates to the technical field of water heaters, in particular to a porous medium burner.

Background

At present, a gas quick water heater is commonly adopted in families, and the water heater adopts a fin structure to exchange heat, so that the volume is large and heavy. The porous medium combustion technology has the advantages of high combustion rate, low pollutant discharge in flue gas, wide combustion limit, combustibility, low heat value gas and the like, and can obviously reduce NOx and CO discharge and widen the load adjusting range when being applied to gas equipment.

In the prior art, a porous medium is arranged in a combustion chamber of the burner to improve the combustion efficiency, however, the conventional burner using the porous medium combustion technology has a condition of uneven heating, and in view of the problem, improvement is required to be made for the problem.

Disclosure of Invention

The application aims to provide a porous medium burner, which aims to solve the technical problem that the existing burner using porous medium is not heated uniformly.

In order to achieve the above purpose, the application provides the following scheme:

a porous medium burner for use in a water heater, comprising:

a housing including a mixing chamber and a combustion chamber in communication with the mixing chamber;

the porous medium body is arranged in the combustion chamber, is wave-shaped and is provided with a plurality of irregularly distributed and communicated pores;

and the air supply device is communicated with the mixing cavity and is used for providing combustion gas.

Further, the porous medium body comprises a first medium and a second medium, the first medium is arranged close to the mixing cavity, the second medium is connected with the first medium and deviates from the mixing cavity, and the first medium and the second medium are both provided with the pores.

Further, the first medium has a pore density greater than the second medium.

Further, the first medium has a pore density of 50 to 60PPI and the second medium has a pore density of 10 to 30PPI.

Further, the porous medium body is made of foam ceramics.

Further, the combustor also comprises a heat insulation assembly, wherein the heat insulation assembly is attached to the inner wall of the combustion chamber, and the porous medium body is connected with the heat insulation assembly.

Further, the heat insulation assembly is provided with a mounting groove, the mounting groove is used for mounting the porous medium body, and the porous medium body is in clearance fit with the mounting groove.

Further, the burner further comprises an ignition piece, the ignition piece is mounted on the shell, a through groove is formed in the heat insulation assembly, the ignition piece extends into the combustion chamber through the through groove, and the ignition piece is located above the porous medium body.

Further, the burner further comprises a perforated plate arranged in the combustion chamber, the perforated plate is positioned below the porous medium body, the perforated plate is provided with a plurality of through holes, and the through holes are uniformly distributed in a plurality of rows and columns; and/or the number of the groups of groups,

the burner also comprises a plate which is arranged in the combustion chamber and positioned below the porous medium body.

Further, the housing includes an upper case and a lower case, the upper case is connected with the lower case, the combustion chamber is formed in the upper case, and the mixing chamber is formed in the lower case; and/or the number of the groups of groups,

the cross-sectional area of the mixing chamber gradually decreases in the direction of the combustion chamber toward the air supply device.

Compared with the prior art, the application has the beneficial effects that:

1. according to the burner provided by the application, the porous medium body is arranged in the combustion chamber, so that the combustion efficiency is improved, the heating rate of the combustion chamber is improved, the purpose of rapidly heating water is further realized, and in addition, the porous medium body is wavy, so that the combustion chamber is heated uniformly when the burner works;

2. in another embodiment, a perforated plate is arranged in the combustion chamber, and combustion gas passes through a plurality of through holes arranged on the perforated plate, so that the combustion gas can be uniformly distributed in the combustion chamber, and the combustion is more sufficient;

3. in yet another embodiment, a heat insulation component is arranged in the combustion chamber, so that on one hand, the heat insulation function is achieved, the temperature of the combustion chamber can be prevented from radiating outwards, and therefore devices outside the combustion chamber are protected, on the other hand, the heat insulation component is used for heat insulation, and on the other hand, the heat insulation component is used for heat insulation, since the porous medium body is made of foamed ceramic materials, after the burner stops working, the temperature of the combustion chamber can be prevented from falling too fast, explosion of the porous medium body is prevented, and the service life of the porous medium body is prolonged.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a front view of a burner provided by an embodiment of the present application;

FIG. 2 is a perspective view of a burner with a gas removal device provided by an embodiment of the present application;

FIG. 3 is a cross-sectional view of a burner with a gas supply removed provided by an embodiment of the present application;

FIG. 4 is a cross-sectional view of another view of a burner for a gas removal device provided by an embodiment of the present application;

fig. 5 is a perspective view of a cover provided in an embodiment of the present application;

FIG. 6 is a pressure state diagram of a wavy porous medium in a combustion chamber according to an embodiment of the application;

FIG. 7 is a graph of velocity of a wavy porous medium in the same region of a combustion chamber provided by an embodiment of the application;

FIG. 8 is a pressure state diagram of a flat porous medium in a combustion chamber provided by an embodiment of the present application;

FIG. 9 is a graph of velocity of a flat porous medium in the same region of a combustion chamber provided by an embodiment of the present application.

Reference numerals illustrate:

100. a burner; 110. a housing; 111. a mixing chamber; 112. a combustion chamber; 113. an upper case; 114. a lower case; 120. a porous medium; 121. a first medium; 122. a second medium; 130. a gas supply device; 140. a thermal insulation assembly; 141. a first heat insulating member; 1411. a mounting groove; 1412. a through groove; 142. a second heat insulating member; 150. an ignition member; 160. a perforated plate; 170. a cover body; 171. a through port; 180. a plate.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

It should be noted that all directional indications (such as up, down, left, right, front, and rear … …) in the embodiments of the present application are merely used to explain the relative positional relationship between the components, the movement condition, etc. in a specific posture, and if the specific posture is changed, the directional indication is changed accordingly.

It will also be understood that when an element is referred to as being "mounted" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or be indirectly connected to the other element through intervening elements.

Furthermore, the description of "first," "second," etc. in this disclosure is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present application.

The burner is applied to the water heater and is used for heating water in the water heater. Porous medium combustion is a combustion mode in which a porous medium is added to a burner. The burner with porous medium has three heat exchange modes of convection, heat conduction and radiation, so that the temperature of the burning area tends to be uniform, and a stable temperature gradient is maintained. The combustion is stable, and the volume heat strength is high. Compared with free combustion, the porous medium combustion has the advantages of high combustion rate, good combustion stability, large load adjustment range, large heat accumulation intensity, small burner volume, good gas adaptability, low pollutant emission in flue gas, wide combustion limit, low combustible gas with low heat value and the like.

As shown in fig. 1 to 5, a porous medium burner 100 is applied to a water heater, and the burner 100 includes a housing 110, a porous medium body 120, and a gas supply 130. The housing 110 includes a mixing chamber 111 and a combustion chamber 112 in communication with the mixing chamber 111; the porous medium 120 is disposed in the combustion chamber 112, the porous medium 120 has a wave shape, and the porous medium 120 has a plurality of pores (not shown in the figure); the gas supply 130 communicates with the mixing chamber 111, and the gas supply 130 is used to supply combustion gas. Illustratively, the burner 100 provided in this embodiment includes, in order from top to bottom, a combustion chamber 112, a mixing chamber 111, and an air supply 130. The air supply 130 in this embodiment is intended to provide a stable pressure of air to the burner 100, preventing the intake air flow from significantly fluctuating. Note that the combustion gas in this embodiment includes methane and air, that is, methane and air are mixed in the mixing chamber 111 to form the combustion gas. The inlet of the mixing cavity 111 is further provided with a cover 170, the cover 170 is provided with a plurality of through openings 171, the plurality of through openings 171 are uniformly distributed on the cover 170, methane and air enter the mixing cavity 111 through the through openings 171, and the cover 170 is provided with the plurality of through openings 171, so that the air and methane are fully mixed, and combustion gas can be combusted more fully. In this embodiment, the cover 170 has an open hollow structure at one end, and the opening 171 is disposed at an end surface facing away from the opening.

As shown in fig. 1, 3 and 4, the burner 100 provided by the application improves the combustion efficiency by arranging the porous medium 120 in the combustion chamber 112, is beneficial to improving the temperature rising rate of the combustion chamber 112, and further achieves the purpose of quickly heating water, and in addition, the porous medium 120 is wavy, so that the combustion chamber 112 is heated uniformly when the burner 100 works.

As shown in fig. 6, fig. 6 is a gas pressure state diagram of the wavy porous medium in the combustion chamber 112, and it can be seen from the figure that the gas pressure of the combustion gas is large at the lower end and small at the upper end in the downward-upward direction, and the gas pressure gradually decreases from the lower end to the upper end.

As shown in fig. 7, fig. 7 is a velocity diagram of the wavy porous medium in the same region of the combustion chamber 112, and it can be seen from the diagram that, within the period length of the waves, the inside of the wavy porous medium and the upstream and downstream flow fields form periodic velocity distribution, and flames are stabilized by means of the periodic low-velocity flow fields; the defect of unstable flame surface due to the large-plate porous medium structure is well overcome. The flow velocity difference between the central area and the edge area is smaller and the combustion is more uniform.

As shown in fig. 8, fig. 8 is a gas pressure state diagram of the flat porous medium in the combustion chamber 112, and it can be seen from the diagram that the pressure in the combustion chamber 112 does not significantly change when the combustion gas is burned in the combustion chamber 112.

As shown in fig. 9, fig. 9 is a velocity diagram of a flat porous medium in the same region of the combustion chamber 112, and it can be seen from the diagram that the velocity is the same everywhere, and the porous medium cannot play a role of holding flame, so that when the flame surface is curved, the porous medium is in a random equilibrium state, and repeatedly changes among a plurality of possible flame surfaces.

As shown in fig. 1, 3 and 4, as an embodiment, the porous medium body 120 includes a first medium 121 and a second medium 122, where the first medium 121 is disposed near the mixing chamber 111, and the second medium 122 is connected to the first medium 121 and faces away from the mixing chamber 111, and pores are disposed on both the first medium 121 and the second medium 122. Illustratively, the first medium 121 is wavy, the second medium 122 is wavy, and the upper surface of the first medium 121 is attached to the lower surface of the second medium 122, and at the same time, the first medium 121 and the second medium 122 are fixedly mounted on the housing 110. In addition, in the present embodiment, the porous medium 120 is in the form of a double-layer porous medium, and of course, the present application is not limited to this, and the porous medium 120 may be a single-layer porous medium or a three-layer porous medium, for example, as an alternative.

As shown in fig. 1, 3, and 4, as one embodiment, the first medium 121 has a pore density greater than that of the second medium 122. Illustratively, the first medium 121 has a relatively high pore density, and the second medium 122 has a relatively low pore density, i.e., the pore size of the first medium 121 is relatively low and the pore size of the second medium 122 is relatively high. The large aperture of the second medium 122 positioned at the upper layer provides sufficient combustion space for the mixed gas, and can avoid uneven flame distribution caused by uneven combustion of the mixed gas; the porosity of the first medium 121 is smaller, and under the condition that the total volume is the same, the porosity is smaller, the density of holes is larger, and the mixed gas is fully preheated in the lower porous structure by matching with the smaller pore diameter, so that the enthalpy value is improved, and the combustion efficiency is improved. Such a structural design is advantageous in preventing flashback.

As shown in fig. 1, 3, and 4, as an embodiment, the first medium 121 has a pore density of 50 to 60PPI, and the second medium 122 has a pore density of 10 to 30PPI. In this embodiment, the second dielectric 122 is selected from 10 to 30PPI of ceramic foam (PPI, pores per inch of length). It will be appreciated that the greater the number of holes per inch of length, the smaller the pore size thereof; conversely, the smaller the number of holes per inch of length, the larger the pore size. And because the emissivity and thermal conductivity of alumina are small compared to silicon carbide, the first medium 121 is selected from alumina foam ceramic, heat reflux will be reduced, and tempering can be prevented more effectively. The second medium 122 is made of 10-30 PPI foamed ceramic with larger pore diameter, so as to improve the heat backflow of the porous medium 120 and more effectively improve the flame propagation speed.

As shown in fig. 1, 3, and 4, the porous dielectric body 120 is made of foam ceramics as an embodiment. Illustratively, in the present embodiment, the porous medium 120 is alumina foam ceramic, and since the emissivity and thermal conductivity of alumina are smaller than those of silicon carbide, the second medium 122 is alumina foam ceramic, so that heat backflow will be reduced, and tempering can be prevented more effectively.

As shown in fig. 1, 3, and 4, the combustor 100 further includes a heat insulating member 140, and the heat insulating member 140 is bonded to the inner wall of the combustion chamber 112, and the porous medium body 120 is connected to the heat insulating member 140. Illustratively, the insulation assembly 140 includes a first insulation member 141 and a second insulation member 142, the first and second insulation members 141, 142 being generally rectangular, and in this embodiment, there are two first insulation members 141 and two second insulation members 142, two first insulation members 141 being disposed opposite each other, and two second insulation members 142 being disposed opposite each other. That is, in the case where the combustion chamber is rectangular, the four walls of the combustion chamber are sequentially bonded to the first heat insulator 141, the second heat insulator 142, the first heat insulator 141, and the second heat insulator 142. The first heat insulating member 141 and the second heat insulating member 142 are made of fireproof aluminum oxide fiber partition boards, and can resist 1400 ℃ high temperature, so that the shell 110 is prevented from being burnt by high temperature combustion, the wall surface is prevented from being high temperature, and other parts are protected. In addition, after the burner 100 stops working, the heat insulation component 140 can also play a role in heat preservation, so that the temperature of the combustion chamber 112 can be slowly reduced, and since the porous dielectric body 120 of the embodiment is made of ceramic, if the temperature is reduced too quickly, the porous dielectric body 120 is easy to crack due to too large temperature difference, so that the heat insulation component 140 can play a role in heat preservation, so that the temperature in the combustion chamber 112 can be slowly reduced, the porous dielectric body 120 is ensured not to crack as much as possible, and the service life of the porous dielectric body 120 is prolonged, thereby improving the service life of the burner 100.

As shown in fig. 1, 3 and 4, in yet another embodiment, the heat insulation component 140 is disposed in the combustion chamber 112, so as to perform a heat insulation function, on one hand, to prevent the temperature of the combustion chamber 112 from radiating outwards, thereby protecting devices outside the combustion chamber 112, and on the other hand, the heat insulation component 140 is used for heat insulation, and since the porous medium 120 is made of foamed ceramic material, after the burner 100 stops working, the temperature of the combustion chamber 112 can be prevented from falling too fast, thereby preventing the porous medium 120 from cracking, and thus being beneficial to prolonging the service life of the porous medium 120.

As shown in fig. 1, 3, and 4, as an embodiment, the heat insulating module 140 is provided with a mounting groove 1411, the mounting groove 1411 is used for mounting the porous dielectric body 120, and the porous dielectric body 120 is in clearance fit with the mounting groove 1411. Illustratively, a mounting slot 1411 is provided on the first insulating member 141, the mounting slot 1411 being rectangular in shape, the first medium 121 and the second medium 122 being fixedly connected to the first insulating member 141 by the mounting slot 1411.

As shown in fig. 1, 3 and 4, as an embodiment, the burner 100 further includes an ignition member 150, the ignition member 150 is mounted on the housing 110, the heat insulation assembly 140 is provided with a through slot 1412, the ignition member 150 extends into the combustion chamber 112 through the through slot 1412, and the ignition member 150 is located above the porous medium body 120. Illustratively, the ignition member 150 is provided to facilitate safe and rapid ignition operations by a user. In this embodiment, the igniter 150 may be configured to strike a fire using an electrical strike. In the present embodiment, two ignition members 150 are provided, and the two ignition members 150 are provided on opposite sides of the housing 110, respectively. That is, two ignition elements 150 may be ignited together or one may be ignited and the other may be used as a spare in the combustion chamber 112, preventing one of the ignition elements 150 from being damaged. This is advantageous for extending the service life of the burner 100. In addition, the through groove 1412 is provided in the first heat insulator 141.

As shown in fig. 1, 3 and 4, as an embodiment, the combustor 100 further includes a perforated plate 160 disposed in the combustion chamber 112, where the perforated plate 160 is located below the porous medium body 120, and the perforated plate 160 is provided with a plurality of through holes (not shown in the drawings), and the through holes are uniformly distributed in a plurality of rows and columns. Illustratively, in the present embodiment, the perforated plate 160 is rectangular, a plurality of through holes are uniformly distributed on the perforated plate 160, and the through holes are uniformly distributed in a plurality of rows and a plurality of columns, and the purpose of the through holes is to disperse the combustion gas, so that the combustion gas can be uniformly distributed in the combustion chamber 112 through the through holes, and the combustion is more complete. In this embodiment, the through holes are circular, however, in a specific application, the through holes may be other shapes, for example, oval, square, or irregular holes, as an alternative. A perforated plate 160 is disposed in the combustion chamber 112, and combustion gas passes through a plurality of through holes formed in the perforated plate 160, so that the combustion gas can be uniformly distributed in the combustion chamber 112, and combustion can be more complete.

As shown in fig. 1, 3 and 4, the burner 100 further includes a plate 180, and the plate 180 is disposed in the combustion chamber 112 and below the porous medium 120. Illustratively, in the present embodiment, the plate 180 is a cordierite plate, which has a low thermal expansion rate due to its good fire resistance. It should be noted that, the plate 180 is located between the perforated plate 160 and the lower shell 114, and the plate 180 is rectangular, however, in a specific application, the shape of the plate 180 is not limited thereto, and for example, as an alternative, the plate 180 may be rounded rectangular, circular, elliptical, regular polygonal, or the like.

As shown in fig. 1, 3, and 4, as an embodiment, the housing 110 includes an upper case 113 and a lower case 114, the upper case 113 is connected to the lower case 114, the combustion chamber 112 is formed in the upper case 113, and the mixing chamber 111 is formed in the lower case 114; the cross-sectional area of the mixing chamber 111 gradually decreases in the direction of the combustion chamber 112 toward the air supply device 130. Illustratively, the housing 110 includes an upper shell 113 and a lower shell 114, the upper shell 113 being fixedly connected to the lower shell 114. The combustion chamber 112 is formed in the upper case 113, and the mixing chamber 111 is formed in the lower case 114. And the upper case 113 is substantially rectangular, and the cross-sectional area of the lower case 114 is gradually increased in a direction from the inlet end of the combustion gas to the upper case 113, it being understood that the cross-sectional area of the mixing chamber 111 is gradually increased in a direction from the inlet end of the combustion gas to the upper case 113. In the present embodiment, the lower case 114 has a substantially quadrangular pyramid shape, however, the shape of the lower case 114 is not limited thereto in a specific application, and for example, the lower case 114 may be a conical shape or a triangular pyramid shape or the like as an alternative. It will be appreciated that the shape of the mixing chamber 111 substantially conforms to the shape of the lower housing 114. The wall surface of the combustion chamber 112 is formed by a cuboid cavity, and a quartz glass material is selected to observe the combustion condition in the combustion chamber 112. In addition, the combustion chamber 112 is provided with small holes on the front, rear, left and right walls for inserting thermocouples to measure the gas-solid temperature, the small holes being filled with refractory fibers.

The burner 100 of the above-described embodiment is applied to a gas water heater, which can improve combustion efficiency and reduce emission of harmful substances. Specifically, the combustion gas flows into the combustion chamber 112 through the mixing chamber 111, and in the combustion chamber 112, the porous medium 120 can greatly improve the uniformity and the sufficiency of combustion, has good combustion stability, inhibits the generation of local high temperature phenomenon, and further can effectively reduce the generation amount of CO and NOx, improve the combustion efficiency of the combustor 100 and reduce environmental pollution.

As shown in fig. 3, the burner 100 of the present application operates: air and methane are supplied by the air supply device 130 and enter the mixing cavity 111 through the through hole 171 on the cover 170 to form combustion gas, then the combustion gas enters the combustion chamber 112 and then continues to move upwards through the through holes on the perforated plate 160, then the combustion gas passes through the holes on the first medium 121 and the second medium 122, the ignition piece 150 above the porous medium 120 ignites, and the combustion gas in the combustion chamber 112 is ignited, and the burner 100 starts to work.

The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the scope of the application, and all equivalent structural changes made by the description of the present application and the accompanying drawings or direct/indirect application in other related technical fields are included in the scope of the application.

Claims (10)

1. A porous medium burner for use in a water heater, comprising:

a housing including a mixing chamber and a combustion chamber in communication with the mixing chamber;

a porous medium body provided in the combustion chamber, the porous medium body having a wave shape, the porous medium body having a plurality of pores;

and the air supply device is communicated with the mixing cavity and is used for providing combustion gas.

2. The burner of claim 1, wherein the porous dielectric body comprises a first medium disposed proximate the mixing chamber and a second medium coupled to the first medium and facing away from the mixing chamber, the first medium and the second medium each having the pores disposed therein.

3. The burner of claim 2, wherein the first medium has a pore density greater than the second medium.

4. The burner of claim 2, wherein the first medium has a pore density of 50 to 60PPI and the second medium has a pore density of 10 to 30PPI.

5. The burner of claim 1, wherein the porous dielectric body is made of foamed ceramic.

6. The burner of claim 1, further comprising an insulation assembly conforming to an inner wall of the combustion chamber, the porous dielectric body being coupled to the insulation assembly.

7. The burner of claim 6, wherein the insulating assembly is provided with mounting slots for mounting the porous dielectric body, and wherein the porous dielectric body is in clearance fit with the mounting slots.

8. The burner of claim 6, further comprising an ignition member mounted to the housing, the insulation assembly being provided with a through slot through which the ignition member extends into the combustion chamber, and the ignition member being positioned above the porous dielectric body.

9. The burner of any of claims 1-8, further comprising a perforated plate disposed in the combustion chamber, the perforated plate being positioned below the porous dielectric body, the perforated plate being provided with a plurality of through holes, the through holes being distributed in a plurality of rows and columns; and/or the number of the groups of groups,

the burner also comprises a plate which is arranged in the combustion chamber and positioned below the porous medium body.

10. The burner of any of claims 1-8, wherein the housing comprises an upper shell and a lower shell, the upper shell being connected to the lower shell, the combustion chamber being formed within the upper shell, the mixing chamber being formed within the lower shell;

the cross-sectional area of the mixing chamber gradually decreases in the direction of the combustion chamber toward the air supply device.