CN111853784A

CN111853784A - Combustion assembly and wall-mounted furnace

Info

Publication number: CN111853784A
Application number: CN201910364071.2A
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: 2020-10-30
Also published as: WO2020221366A1

Abstract

The invention discloses a combustion assembly and a wall-mounted furnace, wherein the combustion assembly comprises: the gas nozzle is connected with an external gas source and provides gas for the combustion equipment; the smoke ejector is communicated with the gas nozzle; the air inlet of the burner is communicated with the outlet of the smoke ejector, and an air ejector port is arranged between the air inlet of the burner and the outlet of the smoke ejector; and one end of the smoke return pipe is communicated with the combustor, and the other end of the smoke return pipe is communicated with the smoke ejector so as to guide smoke generated by the combustor to the smoke ejector to be premixed with gas. According to the combustion assembly provided by the embodiment of the invention, after the flue gas and the fuel gas are premixed in the flue gas ejector, the premixed flue gas and the fuel gas are ejected into the combustor, and the combustion-supporting air is introduced, so that the combustion gas is combusted in a flameless manner, and the emission of oxynitride is reduced.

Description

Combustion assembly and wall-mounted furnace

Technical Field

The invention relates to the technical field of water heaters, in particular to a combustion assembly and a wall-mounted boiler.

Background

Harmful gases such as CO, NOx and the like can be discharged to the outside in the combustion process of the wall-mounted furnace, so that the wall-mounted furnace not only pollutes the environment, but also is very easy to bring danger to personal safety.

Patent No. 201710314570.1 discloses a highly efficient flue gas recirculation system in which flue gas is fed directly into a burner for secondary combustion.

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 and fed into the combustor), not only the combustion of the combustor is unstable, but also 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.

To this end, the invention proposes a combustion assembly which makes it possible to reduce the emission of harmful gases.

The invention also provides a wall-mounted furnace with the combustion assembly, which is safe, environment-friendly and low in pollution.

The combustion assembly of the embodiment of the invention comprises: the gas nozzle is connected with an external gas source and provides gas for the combustion equipment; the smoke ejector is communicated with the gas nozzle; the air inlet of the burner is communicated with the outlet of the smoke ejector, and an air ejector port is arranged between the air inlet of the burner and the outlet of the smoke ejector; and one end of the smoke return pipe is communicated with the combustor, and the other end of the smoke return pipe is communicated with the smoke ejector so as to guide smoke generated by the combustor to the smoke ejector to be premixed with gas.

According to the combustion assembly provided by the embodiment of the invention, after the flue gas and the fuel gas are premixed in the flue gas ejector, the premixed flue gas and the fuel gas are ejected into the combustor, and the combustion-supporting air is introduced, so that the combustion gas is combusted in a flameless manner, and the emission of oxynitride is reduced.

According to some embodiments of the invention, the flue gas injector is sealingly connected to the gas nozzle to isolate the gas and flue gas from air when premixed in the flue gas injector.

In an optional embodiment, a flow regulating valve is arranged on the flue gas return pipe to regulate the flue gas return flow.

According to some embodiments of the invention, one end of the flue gas return pipe communicated with the burner is a smoke taking end, and one end of the flue gas return pipe communicated with the flue gas ejector is an ejecting end.

In an optional embodiment, a strong air extractor is arranged between the smoke extracting end of the smoke return pipe and the burner, and an air outlet of the strong air extractor is communicated with the smoke extracting end of the smoke return pipe.

In an optional embodiment, a strong blower is arranged between the outlet of the flue gas ejector and the air inlet of the combustor, and an air outlet of the strong blower is communicated with the outlet of the flue gas ejector pipe so as to provide air for the air inlet of the combustor.

In an optional embodiment, a smoke collecting hood is arranged between the smoke taking end of the smoke return pipe and the combustor, and the smoke taking end is communicated with the smoke collecting hood.

According to some embodiments of the invention, the mixing ratio of the flue gas and the fuel gas in the flue gas ejector is 1:1-10: 1.

According to some embodiments of the invention, the outlet caliber of the flue gas ejector is smaller than the inlet caliber of the burner.

According to some embodiments of the invention, the distance between the flue gas injector and the burner inlet is less than 10 CM.

According to some embodiments of the invention, the flue gas return pipe is located outside the burner and extends from top to bottom.

In an optional embodiment, the return flue pipe is a corrugated metal pipe.

In a further optional example, a flow regulating valve and a temperature controller are arranged on the smoke return pipe, when the temperature controller detects that the temperature of the smoke is higher than a set value, the flow regulating valve is closed, and the smoke return pipe stops conveying the smoke to the smoke ejector.

According to the wall-hanging furnace provided by the embodiment of the invention, the wall-hanging furnace comprises the combustion assembly of the embodiment, and the nitrogen oxide emission of the combustion assembly is less, so that the pollution to the environment is reduced. Therefore, the wall-mounted furnace provided by the embodiment of the invention is low in pollution, safe and environment-friendly.

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 schematic diagram of a flue gas recycling system according to some embodiments of the present invention;

FIG. 2 is a schematic diagram of a flue gas recycling system according to further embodiments of the present invention.

Reference numerals:

a combustion assembly 100;

a gas nozzle 10;

a gas ejector 20;

a burner 30;

an air injection port 40;

a flue gas return pipe 50;

a flow rate regulating valve 60;

a strong suction fan 71; a strong blower 72;

a smoke collecting hood 80;

and a temperature controller 90.

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.

Accordingly, the present invention is directed to a combustion assembly 100, wherein the combustion assembly 100 can be fed into the combustor 30 for combustion after the gas and the flue gas are sufficiently mixed in advance.

Referring to fig. 1-2, a combustion assembly 100 according to an embodiment of the present invention is described, as shown in fig. 1 and 2, the combustion assembly 100 including: the gas injection device comprises a gas nozzle 10, a gas ejector 20, a burner 30 and a flue gas return pipe 50.

Specifically, the gas nozzle 10 is connected to an external gas source to supply gas to the combustion apparatus. A gas distributing rod and a gas proportional valve are arranged between the gas nozzle 10 and an external gas source, and the injection quantity and the injection pressure of the gas are regulated and controlled through the gas proportional valve and the gas distributing rod.

The smoke ejector is communicated with the gas nozzle 10. Namely, the gas nozzle 10 injects the gas into the flue gas ejector in advance.

An air inlet of the combustor 30 is communicated with an outlet of the smoke ejector, and an air ejection port 40 is arranged between the air inlet of the combustor 30 and the outlet of the smoke ejector. One end of the flue gas return pipe 50 is communicated with the burner 30, and the other end is communicated with the flue gas ejector, so that the flue gas generated by the burner 30 is guided to the flue gas ejector to be premixed with the fuel gas.

That is, the flue gas and the fuel gas of the combustion assembly 100 are pre-mixed in the flue gas injector before entering the combustor 30, the flue gas injector and the combustor 30 are two relatively independent chambers, and the mixed gas of the pre-mixed fuel gas and the flue gas (for short, combustion flue gas) is injected into the combustor 30 again. Wherein, air is synchronously introduced into the combustor 30 through the air injection port 40 to participate in combustion.

The process of mixing the fuel gas and the flue gas is one of two processes, specifically, the fuel gas is injected at a high speed by the fuel gas nozzle 10, a negative pressure is formed in the flue gas ejector at the moment, and the flue gas is quickly sucked into the flue gas ejector to be fully mixed with the fuel gas; secondly, the process of mixing the mixed gas of the flue gas and the fuel gas (called as the fuel gas for short) and the combustion-supporting air is that the fuel gas is sprayed to the combustor 30, meanwhile, negative pressure is formed in the combustor 30, sufficient combustion-supporting air is sucked from the air injection port 40, 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 combustor 30, the combustion gas is combusted in fire holes on the surface of the combustor 30 to generate oxygen-poor flame with relatively low temperature, and because the combustion condition of the flame is in a low-temperature and oxygen-poor state, 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 combustion assembly 100 of the present invention is sequentially provided with the flue gas injector, the burner 30 and the flue gas return pipe 50 in the airflow direction, so as to achieve the purposes of secondary injection and secondary mixing, and finally obtain the uniformly mixed combustion gas, so that the combustion gas is combusted in a flameless manner under the oxygen-poor condition, a relatively low temperature flame is generated, and the emission of nitrogen oxides is reduced.

In short, in the combustion assembly 100 according to the embodiment of the present invention, after the flue gas and the fuel gas are premixed in the flue gas injector, the premixed flue gas and the fuel gas are injected into the combustor 30, and the combustion air is introduced, so that the combustion gas is combusted in a flameless manner, and the emission of nitrogen oxides is reduced.

In some embodiments of the invention, as shown in fig. 1 and 2, the flue gas injector is sealingly connected to the gas nozzle 10 to separate the gas and flue gas from air as they are premixed in the flue gas injector. The smoke ejector is isolated from an external air source and does not introduce air into the smoke ejector, so that the gas and the smoke in the smoke ejector are controlled to be premixed in a proper proportion, and the gas and the smoke are fully and uniformly mixed.

Optionally, a flow regulating valve 60 is disposed on the flue gas return pipe 50 to regulate the flue gas return flow. The smoke inlet amount of the smoke ejector is regulated and controlled by the flow regulating valve 60. Therefore, the proper amount of smoke is obtained in the smoke ejector, and the air inlet ratio of the smoke and the fuel gas is effectively adjusted.

Wherein, the end of the smoke backflow pipe 50 communicated with the burner 30 is a smoke taking end, and the end of the smoke backflow pipe 50 communicated with the smoke ejector is an ejection end. Namely, the smoke generated by the burner 30 is introduced into the smoke return pipe 50 through the smoke taking end, and the smoke is released into the smoke ejector through the ejection end. In other words, the flue gas return pipe 50 is a communicating pipe for communicating the burner 30 and the flue gas ejector. The on-off and the opening of the smoke return pipe 50 determine the amount of smoke entering the smoke ejector.

In an alternative embodiment, as shown in fig. 1, a strong air blower 71 is disposed between the smoke extracting end of the smoke return pipe 50 and the burner 30, and an air outlet of the strong air blower 71 is communicated with the smoke extracting end of the smoke return pipe 50. Namely, the strong air extractor 71 extracts the flue gas in the burner 30, and a part of the flue gas enters the flue gas return pipe 50 from the flue gas taking end, and then is injected into the flue gas injector to be mixed with the fuel gas.

In an alternative embodiment, as shown in fig. 2, a strong blower is provided between the outlet of the smoke ejector and the air inlet of the burner 30, and the air outlet of the strong blower is communicated with the outlet of the smoke ejector pipe to provide air to the air inlet of the burner 30. Thus, the combustion flue gas is injected into the combustor 30, and the air is injected into the combustor 30 through the air injection port 40 under the suction of the strong blower.

In a further alternative example, a smoke collecting hood 80 is arranged between the smoke taking end of the smoke return pipe 50 and the burner 30, and the smoke taking end is communicated with the smoke collecting hood 80. In this embodiment, the flue gas is collected in the chamber defined by the fume collecting hood 80, the flue gas is cooled in the fume collecting hood 80 and is led out by the strong air blower 71, wherein a part of the flue gas flows back to the flue gas ejector through the flue gas return pipe 50 to participate in the secondary combustion. Among them, in some embodiments, the strong draft fan 71 is disposed on the smoke collecting hood 80.

It can be understood that the flue gas flows into the flue gas ejector after being cooled by the smoke collecting hood 80 and the flue gas return pipe 50. Thus, the combustible flue gas is effectively cooled before entering the burner 30, so that the reaction temperature of the combustible flue gas is relatively low, and the low-temperature and oxygen-deficient reaction gas is not beneficial to the generation of oxynitride, thereby effectively reducing the emission of harmful gas.

In an alternative example, the inventor researches and discovers that when the mixing ratio of the flue gas and the fuel gas in the flue gas ejector is controlled to be 1:1-10:1, the harmful gas discharged by the combustor 30 is less. That is, the content of the flue gas in the unit combustion flue gas is greater than or equal to the content of the fuel gas, for example, the mixing ratio of the flue gas to the fuel gas is 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1, it is understood that the above is only illustrative and not a limitation to the mixing ratio of the flue gas to the fuel gas, and the mixing ratio of the flue gas to the fuel gas may be other ratios not illustrated as long as the above range.

Referring to fig. 1 and 2, the outlet caliber of the flue gas ejector is smaller than the inlet pipe diameter of the burner 30. That is, the smoke flowing channel of the smoke ejector is smaller than the smoke flowing channel of the burner 30, that is, the unit flowing area of the smoke flowing body is increased from small to large in the flowing process, and the unit flowing area is suddenly changed, so that the mixing degree of the smoke and the gas can be further promoted, the combustion gas is fully combusted, and the emission of harmful gases is reduced.

In an alternative embodiment, the distance between the flue gas eductor and the inlet of the burner 30 is less than 10 CM. That is, the flue gas injector and the inlet of the burner 30 may be spaced apart to form the air injection port 40, and the distance d between the flue gas injector and the inlet of the burner 30 is 0-10 cm, for example, 1 cm, 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, or 10 cm. Or the outlet of the gas ejector 20 may also be provided with a smoke-burning pipe, the smoke-burning pipe extends into the burner 30, and a plurality of air ejection ports 40 are formed on the pipe wall of the smoke-burning pipe.

The advantage of introducing the combustion air through the air injection port 40 is that the combustion air can be divided into a plurality of small air flows to be introduced into the mixed gas of the fuel gas and the flue gas, so that the mixing uniformity of the flue gas, the fuel gas and the combustion air is further improved.

In an alternative example, the flue gas return pipe 50 is located outside the burner 30 and extends downward from above. That is to say, the return flue gas pipe and the combustor 30 are separately arranged, so that heat exchange hardly occurs between the combustor 30 and the flue gas return pipe 50, and therefore, the temperature of the flue gas in the flue gas return pipe 50 can be better reduced, and the flue gas with proper temperature can be conveyed to the flue gas ejector.

In a further alternative, the flue gas recirculation pipe 50 is a corrugated metal pipe. The flue gas return pipe 50 made of metal material has good heat property and large heat dissipation area, thereby effectively reducing the temperature of the flue gas.

In a further alternative example, the inventors have found in their studies that when the temperature of the flue gas is too high, the combustion of the harmful gases by the burner 30 is high compared to the normal combustion (i.e. when no flue gas is introduced), and therefore, it is important for the temperature regulation of the flue gas. According to the invention, the flue gas return pipe 50 is provided with the flow regulating valve 60 and the temperature controller 90, when the temperature controller 90 detects that the temperature of the flue gas is higher than a set value, the flow regulating valve 60 is closed, and the flue gas return pipe 50 stops conveying the flue gas to the flue gas ejector. Therefore, when the temperature of the flue gas is too high, the flue gas is stopped from being conveyed to the flue gas ejector.

The wall-hanging furnace according to the embodiment of the invention comprises the combustion assembly 100 of the embodiment, and the nitrogen oxides discharged by the combustion assembly 100 of the embodiment of the invention are less, so that the pollution to the environment is reduced. Therefore, the wall-mounted furnace provided by the embodiment of the invention is low in pollution, safe and environment-friendly.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean 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 combustion assembly, comprising:

the gas nozzle is connected with an external gas source and provides gas for the combustion equipment;

the smoke ejector is communicated with the gas nozzle;

the air inlet of the burner is communicated with the outlet of the smoke ejector, and an air ejector port is arranged between the air inlet of the burner and the outlet of the smoke ejector;

and one end of the smoke return pipe is communicated with the combustor, and the other end of the smoke return pipe is communicated with the smoke ejector so as to guide smoke generated by the combustor to the smoke ejector to be premixed with gas.

2. The combustion assembly of claim 1, wherein the flue gas injector is sealingly connected to the gas nozzle to separate the gas and flue gas from air during premixing in the flue gas injector.

3. The burner assembly of claim 2 wherein a flow control valve is provided in the flue gas return conduit to regulate the flow of flue gas return.

4. The combustion assembly of claim 1, wherein the end of the flue gas return pipe communicated with the burner is a smoke taking end, and the end of the flue gas return pipe communicated with the flue gas ejector is an ejecting end.

5. The combustion assembly as claimed in claim 4, wherein a strong air blower is arranged between the smoke taking end of the smoke return pipe and the burner, and an air outlet of the strong air blower is communicated with the smoke taking end of the smoke return pipe.

6. The combustion assembly of claim 4, wherein the outlet of the flue gas injector and the inlet of the burner are provided with a strong blower, and the air outlet of the strong blower is communicated with the outlet of the flue gas injector pipe to provide air to the inlet of the burner.

7. A combustion assembly according to any of claims 4-6, wherein a smoke collection hood is provided between the smoke withdrawal end of the smoke return conduit and the burner, the smoke withdrawal end being in communication with the smoke collection hood.

8. The combustion assembly of claim 1, wherein the mixing ratio of the flue gas to the fuel gas in the flue gas ejector is 1:1-10: 1.

9. The combustion assembly of claim 1, wherein the outlet orifice of the flue gas eductor is smaller than the inlet orifice diameter of the burner.

10. The combustion assembly of claim 1, wherein the distance between the flue gas injector and the burner inlet is less than 10 CM.

11. The burner assembly of claim 1 wherein the flue gas return line is located outside of the burner and extends downwardly from above.

12. The burner assembly of claim 11 wherein the flue gas return conduit is a corrugated metal tube.

13. The combustion assembly as claimed in claim 3, wherein the flue gas return pipe is provided with a flow control valve and a temperature controller, and when the temperature controller detects that the temperature of the flue gas is higher than a set value, the flow control valve is closed, and the flue gas return pipe stops conveying the flue gas to the flue gas ejector.

14. A wall hanging stove comprising a burner assembly as claimed in any one of claims 1 to 6 or 8 to 13.