CN111853785B

CN111853785B - Combustor and gas heater

Info

Publication number: CN111853785B
Application number: CN201910365260.1A
Authority: CN
Inventors: 陆旭; 寿利萍; 赵光军; 梁国荣; 彭晶
Original assignee: Midea Group Co Ltd; Wuhu Midea Kitchen and Bath Appliances Manufacturing Co Ltd
Current assignee: Midea Group Co Ltd; Wuhu Midea Kitchen and Bath Appliances Manufacturing Co Ltd
Priority date: 2019-04-30
Filing date: 2019-04-30
Publication date: 2022-12-06
Anticipated expiration: 2039-04-30
Also published as: WO2020221367A1; CN111853785A

Abstract

The invention discloses a burner and a gas water heater, wherein the burner comprises: a plurality of sequentially connected combustion units, each of the combustion units comprising: the combustion chamber is positioned above the mixing chamber; the combustion panel is positioned above the combustion cavity, and a plurality of fire outlets are formed in the combustion panel; and the smoke distributor is used for conveying mixed gas of fuel gas and smoke gas to each combustion unit. According to the burner provided by the embodiment of the invention, before the fuel gas and the flue gas enter the combustion unit, the fuel gas and the flue gas are mixed in the flue gas distributor in advance and then are sent to the combustion unit for combustion, so that the stability of combustion of the burner is ensured, and the emission of harmful gas is reduced.

Description

Combustor and gas heater

Technical Field

The invention relates to the technical field of water heaters, in particular to a burner and a gas water heater.

Background

Harmful gases such as CO, NOx and the like can be discharged to the outside in the combustion process of the gas water heater, so that the environment is polluted, and the danger is easily brought to the personal safety.

Patent No. 201710314570.1 discloses a high-efficiency flue gas circulation system, in which flue gas is directly fed into a combustor for secondary combustion, and the purpose is to reduce the emission of harmful gases.

In fact, the inventor finds in research that if the flue gas is directly fed into the combustor for combustion (i.e. the flue gas and the flue gas are not sufficiently mixed, the flue gas is fed into the combustor), the combustion of the combustor is not stable, and the emission of harmful gases cannot be effectively reduced.

Disclosure of Invention

The present invention aims to solve at least one of the above technical problems to a certain extent.

Therefore, the invention provides the burner which is stable in combustion and low in harmful gas emission.

The invention also provides a gas water heater comprising the burner, and the gas water heater is safe and environment-friendly.

A burner according to an embodiment of the present invention includes: a plurality of combustion units connected in series, each combustion unit comprising: the combustion chamber is positioned above the mixing chamber; the combustion panel is positioned above the combustion cavity, and a plurality of fire outlets are formed in the combustion panel; and the smoke distributor is used for conveying mixed gas of fuel gas and smoke gas to each combustion unit.

According to the burner provided by the embodiment of the invention, before the fuel gas and the flue gas enter the combustion unit, the fuel gas and the flue gas are mixed in the flue gas distributor in advance and then are sent into the combustion unit for combustion, so that the stability of combustion of the burner is ensured, and the emission of harmful gas is reduced.

According to some embodiments of the invention, the mixing chamber is provided with an air inlet at a rear end thereof and an air outlet at a front end thereof.

In an optional embodiment, a rotational flow structure is arranged in the mixing cavity and is located between the air inlet and the air outlet.

In an optional example, the swirling structure is formed by connecting a plurality of L-shaped plates end to end.

According to some embodiments of the present invention, a flow equalizing plate is disposed in the combustion chamber, the flow equalizing plate and the combustion panel are spaced from each other in an up-down direction, and the flow equalizing plate is provided with an air hole.

In an alternative example, the number of the air passing holes of the flow equalizing plate at one end close to the combustion chamber inlet is less than that of the air passing holes of the flow equalizing plate at the other end far away from the combustion chamber inlet.

In an alternative example, the aperture of the air passing hole of the flow equalizing plate at one end adjacent to the combustion chamber inlet is smaller than the aperture of the air passing hole of the flow equalizing plate at the other end far away from the combustion chamber inlet.

In an alternative example, the combustion panel is provided with a flow stabilizer plate protruding from an upper surface thereof, and the flow stabilizer plate divides the fire outlet holes into a plurality of groups.

In one embodiment of the invention, a plurality of the flow stabilizing plates are arranged between the fire holes of the adjacent groups, and the plurality of the flow stabilizing plates are distributed along the left and right direction of the combustion unit.

In a specific embodiment of the invention, a gap is formed between the flow stabilizing plate and the upper surface of the combustion unit, and the gap can be communicated with the fire outlets of the adjacent groups.

In one embodiment of the invention, each group of the fire holes is divided into a plurality of subgroups, and the fire holes of adjacent subgroups are spaced.

According to some embodiments of the invention, the flue gas distributor defines a premixing chamber having a gas inlet provided with a gas nozzle, a flue gas inlet and a mixed gas outlet, the gas nozzle extending into the premixing chamber opposite to the mixed gas outlet.

In an optional embodiment, the flue gas distributor is a cavity structure with an open upper end, a flue gas inlet is formed on a top plate of the flue gas distributor, and the horizontal distance between a front plate and a rear plate of the flue gas distributor is gradually reduced from top to bottom.

In an optional embodiment, the mixed gas outlet is provided with an injection pipe, and the injection pipe is arranged at a distance from the mixing cavity.

In an optional embodiment, the mixed gas outlet is provided with an injection pipe, an injection pipe matched with the injection pipe is arranged in the mixing cavity, and the part of the injection pipe extending out of the mixing cavity is provided with an air introduction hole.

The gas water heater according to the embodiment of the second aspect of the invention comprises the burner of the above embodiment, and the burner according to the embodiment of the invention is stable in combustion and discharges less harmful gas, so that the gas water heater according to the embodiment of the invention is safe and environment-friendly and is stable in combustion.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a perspective view of a burner according to some embodiments of the present invention;

FIG. 2 is a cross-sectional view of FIG. 1;

FIG. 3 is a front view of FIG. 2;

FIG. 4 is a top view of a combustor according to other embodiments of the present invention;

FIG. 5 is a cross-sectional view of a combustor according to other embodiments of the present invention;

FIG. 6 is a front view of FIG. 5;

fig. 7 is an enlarged view of a portion of the burner of fig. 2.

Reference numerals:

a combustor 100;

a combustion unit 10;

a mixing chamber 11; an air inlet 111; an air outlet 112; a swirling structure 113;

a combustion chamber 12;

a combustion panel 13; a fire outlet 131; a flow stabilizer 132; a void 1321;

a flow equalizing plate 14; a gas passing hole 141;

an injection pipe 15; an air introduction hole 151;

a flue gas distributor 20;

a premix chamber 21; a gas inlet 211; a flue gas inlet 212; a mixed gas outlet 213;

a gas nozzle 22;

a top plate 23;

a front plate 24;

a rear plate 25;

and an injection pipe 26.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

The inventor finds that mixed gas consisting of fuel gas, combustion air and flue gas can be combusted in a flameless mode in multiple combustion tests, and harmful gas discharged by flameless combustion is greatly reduced compared with flame combustion.

The inventor further finds that the mixing degree of the fuel gas and the flue gas is related to the emission of harmful gases of the flue gas, and the more uniform the mixing of the fuel gas and the flue gas is, the less the emission of the harmful gases is.

Referring to fig. 1 to 7, a burner 100 according to an embodiment of the present invention is described, the burner 100 being applied to a gas water heater to heat cold water in a heat exchanger in the gas water heater.

Referring to fig. 1 and 2, 4 and 5, the burner 100 includes a plurality of combustion units 10 and a flue gas distributor 20.

Specifically, as shown in fig. 1 and 4, the burner 100 includes a plurality of sequentially connected combustion units 10. As shown in fig. 2 and 3, and fig. 5 and 6, each combustion unit 10 includes: a mixing cavity 11 and a combustion cavity 12 which are communicated with each other, wherein the combustion cavity 12 is positioned above the mixing cavity 11. That is, the combustion gas firstly enters the mixing chamber 11 to be fully mixed, and then enters the combustion chamber 12 to be mixed.

Wherein, the combustion panel 13 is located above the combustion chamber 12, and a plurality of fire holes 131 are formed on the combustion panel 13. In other words, the gas introduced into the combustion chamber 12 flows out through the fire hole 131 and is ignited, and the upper surface of the combustion panel 13 forms a combustion area, and the cold water in the heat exchanger is heated by the combustion area.

The flue gas distributor 20 feeds a mixture of gas and flue gas to each of the combustion units 10. In the present embodiment, the gas and flue gas are premixed in the flue gas distributor 20 before being fed into the combustion unit 10.

That is, when the burner 100 is operated, the flue gas and the gas are premixed in the flue gas distributor 20, and then enter the mixing chamber 11 of the combustion unit 10, and the combustion air is brought into the mixing chamber 11 along with the mixed gas of the flue gas and the gas. Because the combustion gas contains the flue gas which is uniformly mixed, the proportion of combustion-supporting air in the combustion gas is effectively diluted, so that the combustion chemical reaction of the combustion unit 10 is in an oxygen-deficient state, the temperature in the whole reaction process is low, and the generation of harmful gases such as CO, NOx and the like is not facilitated.

Specifically, the process of the gas and the flue gas entering the burner 100 basically comprises two processes, one is a process of mixing the gas and the flue gas, specifically, the gas nozzle 22 sprays the gas at a high speed, a negative pressure is formed in the flue gas distributor 20 at the moment, and the flue gas is quickly sucked into the flue gas distributor 20 to be fully mixed with the gas; secondly, the process of mixing the mixed gas of the flue gas and the fuel gas (called as the flue gas for short) and the combustion-supporting air is that the flue gas is sprayed to the mixing cavity 11, negative pressure is formed in the mixing cavity 11, sufficient combustion-supporting air is sucked from the air introducing hole 151, and finally uniform mixed gas of the flue gas, the combustion-supporting air and the fuel gas (called as the combustion gas for short) is formed in the mixing cavity 11, the combustion gas is combusted in the fire holes on the surface of the combustion cavity to generate oxygen-poor flame with relatively low temperature, and the combustion condition of the flame is in a low-temperature and oxygen-poor state, so that the generation of oxynitride is effectively inhibited, and the emission of oxynitride of the flue gas is greatly reduced.

It can be understood that the burner 100 of the present invention is sequentially provided with the flue gas distributor 20, the mixing chamber 11 and the combustion chamber 12 in the airflow direction, so as to achieve the purposes of secondary injection and secondary mixing, finally obtain uniformly mixed combustion gas, achieve flameless combustion of the combustion gas under oxygen-deficient conditions, generate flame with relatively low temperature, and reduce the emission of nitrogen oxides.

According to the burner 100 provided by the embodiment of the invention, before the fuel gas and the flue gas enter the combustion unit 10, the fuel gas and the flue gas are mixed in the flue gas distributor 20 in advance and then are sent to the combustion unit 10 for combustion, so that the stability of the combustion of the burner 100 is ensured, and the emission of harmful gases is reduced.

In an alternative embodiment, as shown in fig. 2 and 3, and fig. 5 and 6, the rear end of the mixing chamber 11 (e.g., the rear end in fig. 2) is provided with an air inlet 111, and the front end of the mixing chamber 11 (e.g., the front end in fig. 2) is provided with an air outlet 112. The mixed gas of the fuel gas and the flue gas injects combustion-supporting air into the mixing chamber 11, and the gas inlet 111 and the gas outlet 112 of the mixing chamber 11 are positioned at the two ends in the front-back direction, so that the flow path of the combustion gas in the mixing chamber 11 is prolonged, and the fuel gas, the flue gas and the combustion-supporting air are fully and uniformly mixed in the mixing chamber 11. It should be noted that, the term "combustion gas" as used herein refers to a mixture of flue gas, combustion air and flue gas.

In a further alternative embodiment, a rotational flow structure 113 is disposed in the mixing chamber 11, and the rotational flow structure 113 is located between the air inlet 111 and the air outlet 112. The combustion gas may impinge on the swirling structure 113, thereby further sufficiently mixing the combustion gas by the swirling structure 113.

In an alternative example, the swirling structure 113 is formed by connecting a plurality of L-shaped plates end to end. This forms a curved collision surface in the mixing chamber 11, and further sufficiently mixes the combustion gas.

In an alternative embodiment, a flow equalizing plate 14 is disposed in the combustion chamber 12, the flow equalizing plate 14 and the combustion panel 13 are spaced from each other in the vertical direction, and the flow equalizing plate 14 is provided with air passing holes 141. After the airflow of the combustion gas enters the combustion chamber 12, the airflow is dispersed into small airflow through the air passing holes 141, and the small airflow which is uniformly dispersed is ignited after passing through the fire outlet 131. Thereby, it is ensured that all the fire holes 131 of the combustion panel 13 can obtain the combustion gas with stable and same flow rate, so that a stable and uniform flame is formed in the combustion area of the combustion panel 13.

In an alternative example, the number of the air holes 141 of the flow equalizing plate 14 adjacent to the inlet of the combustion chamber 12 is less than the number of the air holes 141 of the flow equalizing plate 14 at the other end away from the inlet of the combustion chamber 12. Referring to fig. 2 and 3, and fig. 5 and 6, since the inlet of the combustion chamber 12 is communicated with the outlet of the mixing chamber 11, the concentration of the gas flow at the inlet of the combustion chamber 12 is necessarily high, and therefore the number of the gas passing holes 141 of the flow equalizing plate 14 adjacent to the area is small, and the amount of the combustion gas passing through the area can be reduced properly. Thereby, it is ensured that all the gas outlet holes of the combustion panel 13 obtain a comparable amount of combustion gas.

In an alternative example, as shown in fig. 2, the aperture of the air holes 141 of the flow equalizing plate 14 near the inlet of the combustion chamber 12 is smaller than the aperture of the air holes 141 of the flow equalizing plate 14 far from the inlet of the combustion chamber 12. Thereby, it is ensured that all the gas outlet holes of the combustion panel 13 obtain a comparable amount of combustion gas.

In a further alternative example, the combustion panel 13 is provided with a flow stabilizer plate 132 protruding from the upper surface thereof, the flow stabilizer plate 132 dividing the fire holes 131 into a plurality of groups. That is, the current stabilizer 132 is positioned between each set of fire holes 131. A flow stabilizing plate 132 is arranged between the fire outlets 131 of adjacent groups. Under the action of the flow stabilizing plates 132, the fire holes 131 of adjacent groups are not easy to generate fire cross phenomenon, and the combustion unit can be ensured to stably combust.

In one embodiment, as shown in fig. 1, 4 and 7, a plurality of flow stabilizers 132 are disposed between each adjacent group of the fire holes 131, and the plurality of flow stabilizers 132 are distributed in the left and right direction of the combustion unit. A gap 1321 is formed between the current stabilizer 132 and the upper surface of the combustion unit 10, and the gap 1321 may communicate with the adjacent group of fire holes 131. The two adjacent groups of fire holes 131 can spread the flame through the gap 1321, that is, when one group of fire holes 131 is ignited, the adjacent fire holes 131 are also ignited, so that the fire holes 131 of the whole combustion panel 13 are all ignited.

Further, as shown in fig. 4 and 5, each group of the fire holes 131 is divided into a plurality of subgroups, and the fire holes 131 of adjacent subgroups are arranged at intervals. Thus, the fire holes 131 of each group can be independently ignited, and the fire holes 131 of each adjacent group are arranged at intervals to avoid fire crossing, thereby improving the combustion stability of the combustion panel 13.

In an alternative embodiment, as shown in fig. 2 and 3, and fig. 4 and 5, the flue gas distributor 20 defines a premixing chamber 21, the premixing chamber 21 has a gas inlet 211, a flue gas inlet 212 and a mixed gas outlet 213, the gas inlet 211 is provided with a gas nozzle 22, and the gas nozzle 22 extends into the premixing chamber 21 and is arranged opposite to the mixed gas outlet 213. The gas nozzle 22 jets out gas with certain pressure, and the gas is rushed to the mixed gas outlet 213, so that negative pressure is formed in the premixing cavity 21, the smoke is rapidly sucked into the premixing cavity 21 to be premixed with the gas, then the smoke flows into the mixing cavity 11, the rapidly flowing smoke and the gas enable negative pressure to be formed in the mixing cavity 11, so that combustion-supporting air is jetted into the mixing cavity 11, and finally the smoke, the gas and the combustion-supporting air are fully mixed in the mixing cavity 11.

In an alternative example, as shown in fig. 3 and 6, the flue gas distributor 20 is a cavity structure with an open upper end, the top plate 23 of the flue gas distributor is formed with a flue gas inlet 212, and the horizontal distance between the front plate 24 and the rear plate 25 of the flue gas distributor 20 is gradually reduced from top to bottom. That is, the flow area of the flue gas is gradually reduced from top to bottom, and the change of the flow area can promote the generation of turbulence in the premixing cavity 21 in the flue gas, which is more beneficial to the mixing of the flue gas and the fuel gas.

In one embodiment, as shown in fig. 2 and 3, the mixed gas outlet 213 is provided with an injection pipe 26, and the injection pipe 26 is spaced apart from the mixing chamber 11. The flue gas and the fuel gas are conveyed into the mixing chamber 11 through the injection pipe 26, and combustion air is introduced by utilizing the gap between the mixing chamber 11 and the injection pipe 26.

In another embodiment, as shown in fig. 5 and 6, the mixed gas outlet 213 is provided with an injection pipe 26, the mixing chamber 11 is provided with an injection pipe 15 matching with the injection pipe 26, and a portion of the injection pipe 15 extending out of the mixing chamber 11 is provided with an air introducing hole 151.

The gas water heater according to the embodiment of the invention comprises the burner 100 of the above embodiment, and the burner 100 according to the embodiment of the invention is stable in combustion and discharges less harmful gas, so that the gas water heater according to the embodiment of the invention is safe and environment-friendly and is stable in combustion.

In the present invention, unless expressly stated or limited otherwise, the recitation of a first feature "on" or "under" a second feature may include the recitation of the first and second features being in direct contact, and may also include the recitation that the first and second features are not in direct contact, but are in contact via another feature between them. Also, the first feature "on," "above" and "over" the second feature may include the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is at a higher level than the second feature. The first feature being "under," "beneath," and "under" the second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.

In the description of the specification, reference to the description of "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" or the like means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention.

Claims

1. A burner, comprising:

a plurality of combustion units connected in series, each combustion unit comprising:

the combustion chamber is positioned above the mixing chamber;

the combustion panel is positioned above the combustion cavity, and a plurality of fire outlets are formed in the combustion panel;

the smoke distributor is used for respectively conveying mixed gas of fuel gas and smoke gas to each combustion unit; the flue gas distributor defines a premixing cavity, the premixing cavity is provided with a gas inlet, a flue gas inlet and a mixed gas outlet, the gas inlet is provided with a gas nozzle, the gas nozzle extends into the premixing cavity and is arranged opposite to the mixed gas outlet, the flue gas distributor is of a cavity structure with an open upper end, the top plate of the flue gas distributor is provided with the flue gas inlet, the horizontal distance between the front plate and the rear plate of the flue gas distributor is gradually reduced from top to bottom, the mixed gas outlet is provided with an injection pipe, the injection pipe and the mixing cavity are arranged at intervals, an injection pipe matched with the injection pipe is arranged in the mixing cavity, and the part of the injection pipe extending out of the mixing cavity is provided with an air introduction hole;

the rear end of the mixing cavity is provided with an air inlet, and the front end of the mixing cavity is provided with an air outlet; and a rotational flow structure is arranged in the mixing cavity and is positioned between the air inlet and the air outlet.

2. The burner of claim 1, wherein the swirl structure is formed by a plurality of L-shaped plates connected end to end.

3. The burner of claim 1, wherein a flow equalizing plate is disposed in the combustion chamber, the flow equalizing plate and the combustion panel are spaced apart from each other in an up-down direction, and the flow equalizing plate is provided with air holes.

4. The burner of claim 3 wherein the number of overfire holes of said flow equalizer plate adjacent the inlet of said combustion chamber is less than the number of overfire holes of said flow equalizer plate at the end of said flow equalizer plate remote from said inlet of said combustion chamber.

5. The burner of claim 3 wherein the apertures of the air passing holes of the flow equalizing plate at one end adjacent to the combustion chamber inlet are smaller than the apertures of the air passing holes of the flow equalizing plate at the other end remote from the combustion chamber inlet.

6. The burner as claimed in claim 4, wherein the combustion panel is provided with flow stabilizers protruding from an upper surface thereof, the flow stabilizers dividing the fire holes into a plurality of groups.

7. The burner of claim 6, wherein a plurality of the flow stabilizers are disposed between adjacent groups of the fire holes, and are distributed in a left-right direction of the combustion unit.

8. The burner of claim 6, wherein a gap is formed between the stabilizer plate and the upper surface of the combustion unit, and the gap is capable of communicating with adjacent groups of the fire holes.

9. The burner of claim 6 wherein each group of the flame ports is divided into a plurality of subgroups, the flame ports of adjacent subgroups being spaced apart.

10. A gas water heater comprising a burner as claimed in any one of claims 1 to 9.