WO2020221366A1

WO2020221366A1 - Combustion assembly and wall-mounted stove

Info

Publication number: WO2020221366A1
Application number: PCT/CN2020/088526
Authority: WO
Inventors: 陆旭; 寿利萍; 赵光军; 梁国荣; 彭晶
Original assignee: 芜湖美的厨卫电器制造有限公司; 美的集团股份有限公司
Priority date: 2019-04-30
Filing date: 2020-04-30
Publication date: 2020-11-05
Also published as: CN111853784A

Abstract

Disclosed is a combustion assembly (100) and a wall-mounted stove comprising the combustion assembly (100). The combustion assembly (100) comprises: a gas nozzle (10) connected to an external gas source and providing fuel gas for a combustion device; a smoke ejector (20) in communication with the gas nozzle (10); a burner (30), with a gas inlet of the burner (30) being in communication with an outlet of the smoke ejector (20), and an air ejection port (40) being provided between the gas inlet of the burner (30) and the outlet of the smoke ejector (20); and a smoke return pipe (50), with one end of the smoke return pipe (50) being in communication with the burner (30), and the other end thereof being in communication with the smoke ejector (20), such that the smoke generated by the burner (30) is guided to the smoke ejector (20) and is pre-mixed with the fuel gas. According to the combustion assembly (100), the smoke and the fuel gas are pre-mixed in the smoke ejector (20) and are then ejected into the burner (30), and at the same time, the combustion air is introduced, such that the combustion gas burns in a flameless manner, thereby reducing the emission of oxynitrides.

Description

Combustion components and wall-hung boilers

Cross references to related applications

This application is based on a Chinese patent application whose application number is 201910364071.2 and the filing date is April 30, 2019, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby incorporated by reference into this application.

Technical field

This application relates to the technical field of water heaters, and more specifically, to a combustion assembly and a wall-hung boiler.

Background technique

During the combustion process of the wall-hung boiler, harmful gases such as CO and NOx will be emitted to the outside world, which not only pollutes the environment but also easily brings danger to personal safety.

Patent No. 201710314570.1 discloses a high-efficiency flue gas circulation system. In this patent document, flue gas is directly fed into a burner for secondary combustion.

The inventor found in the research that if the flue gas is directly fed into the burner for combustion (that is, if the gas and flue gas are not sufficiently mixed and sent to the burner), it will not only make the burner unstable, but also cannot effectively reduce harmful gases. Emissions.

Summary of the invention

This application aims to solve one of the above technical problems at least to a certain extent.

For this reason, this application proposes a combustion assembly, which can reduce harmful gas emissions.

This application also proposes a wall-hung boiler with the above combustion assembly that is safe, environmentally friendly, and less polluting.

The combustion assembly of the embodiment of the present application includes: a gas nozzle connected to an external gas source to provide gas to the combustion device; a flue gas ejector connected to the gas nozzle; a combustor, an air inlet of the combustor Connected with the outlet of the flue gas ejector, an air ejection port is arranged between the burner inlet and the outlet of the flue gas ejector; a flue gas return pipe, one end of the flue gas return pipe is connected to the The burner is in communication, and the other end is in communication with the flue gas ejector to guide the flue gas generated by the burner to the flue gas ejector for premixing with the gas.

In the combustion assembly of the embodiment of the present application, after premixing the flue gas and fuel gas in the flue gas ejector, they are introduced into the combustor, and at the same time, the combustion-supporting air is introduced, so that the combustion gas is combusted in a flameless manner, reducing nitrogen The emissions of oxygen compounds.

According to some embodiments of the present application, the flue gas ejector is connected to the gas nozzle in a sealed manner, so that the gas and flue gas are premixed in the flue gas ejector to isolate air.

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

According to some embodiments of the present application, one end of the flue gas return pipe connected to the burner is a smoke taking end, and one end of the flue gas return pipe connected to the smoke ejector is an ejector end.

In an alternative embodiment, a strong exhaust fan is arranged between the smoke extraction end of the flue gas return pipe and the burner, and the air outlet of the strong exhaust fan is in communication with the smoke extraction end of the flue gas return pipe.

In an optional embodiment, a strong blower is provided at the outlet of the flue gas ejector and the air inlet of the combustor, and the air outlet of the strong blower is in communication with the outlet of the flue gas ejection pipe to direct the The burner inlet provides air.

In an optional embodiment, a smoke collecting hood is provided between the smoke taking end of the flue gas return pipe and the burner, and the smoke taking end is in communication with the smoke collecting hood.

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

According to some embodiments of the present application, the outlet diameter of the flue gas ejector is smaller than the inlet pipe diameter of the burner.

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

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

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

In a further optional example, the flue gas return pipe is provided with a flow regulating valve and a thermostat, and when the thermostat detects that the temperature of the flue gas is higher than a set value, the flow regulating valve is closed, so The flue gas return pipe stops delivering flue gas to the flue gas ejector.

The wall-hung boiler according to the embodiment of the present application includes the combustion assembly of the above-mentioned embodiment. Since the combustion assembly according to the embodiment of the present application emits less nitrogen oxides, the environmental pollution is reduced. Therefore, the wall-hung boiler according to the embodiments of the present application has low pollution, is safe and environmentally friendly.

The additional aspects and advantages of the present application will be partially given in the following description, and some will become obvious from the following description, or be understood through the practice of the present application.

Description of the drawings

The above and/or additional aspects and advantages of the present application will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, in which:

Figure 1 is a schematic structural diagram of a flue gas recycling system according to some embodiments of the present application;

Figure 2 is a schematic structural diagram of a flue gas recycling system according to other embodiments of the present application.

Reference signs:

Combustion component 100;

Gas nozzle 10; gas ejector 20;

Burner 30; air injection port 40; flue gas return pipe 50; flow control valve 60;

Strong exhaust fan 71; Strong blower 72;

Smoke collecting hood 80; thermostat 90.

Detailed ways

The embodiments of the present application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary, and are intended to explain the application, but should not be understood as a limitation to the application.

The inventor has found in multiple combustion tests that the mixed gas composed of fuel gas, combustion air and flue gas can be burned in a flameless manner. Compared with flame combustion, the harmful gases emitted by flameless combustion are greatly reduced.

The inventor further found that the degree of mixing of gas and flue gas is related to the emission of harmful gases in the flue gas. The more uniform the mixture of gas and flue gas, the less harmful gas emissions are.

Therefore, the present application strives to provide a combustion assembly 100 that can be sent into the combustor 30 for combustion after the gas and flue gas are fully mixed in advance.

1 and 2, the combustion assembly 100 according to an embodiment of the present application is described. As shown in FIGS. 1 and 2, the combustion assembly 100 includes: 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 with an external gas source to provide gas to the combustion equipment. A gas distribution rod and a gas proportional valve are arranged between the gas nozzle 10 and the external gas source, and the gas injection volume and injection pressure are controlled by the gas proportional valve and the gas distribution rod.

The flue gas ejector is in communication with the gas nozzle 10. That is, the gas nozzle 10 injects gas into the flue gas ejector in advance.

The air inlet of the combustor 30 is in communication with the outlet of the smoke ejector, and an air ejection port 40 is provided 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 in communication with the burner 30, and the other end is in communication with the flue gas ejector to guide the flue gas generated by the burner 30 to the flue gas ejector for premixing with the gas.

In other words, the flue gas and fuel gas of the combustion assembly 100 are pre-mixed in the flue gas ejector before entering the combustor 30. The flue gas ejector and the combustor 30 are two relatively independent chambers. The mixed gas of fuel gas and flue gas (smoke gas for short) is introduced into the combustor 30 again. Among them, the air is synchronously introduced into the combustor 30 through the air injection port 40 to participate in the combustion.

Among them, the gas and flue gas entering the combustor 30 basically include two processes. One is the process of mixing gas and flue gas, which is specifically as follows. The gas nozzle 10 injects gas at a high speed, and a negative pressure is formed in the flue gas ejector. , The flue gas is quickly sucked into the flue gas ejector and fully mixed with the gas; second, the mixing process of the mixed gas of flue gas and gas (referred to as the combustion gas) and the combustion air, as follows, the combustion gas is injected To the burner 30, a negative pressure is formed in the burner 30 at the same time, and enough combustion air is sucked in from the air injection port 40, and finally a uniform mixture of flue gas, combustion air and fuel gas (abbreviated as Combustion gas), the combustion gas burns on the surface of the burner 30 to produce a relatively low-temperature oxygen-lean flame. Since the combustion conditions of the flame are in a low-temperature and oxygen-lean state, the formation of nitrogen oxides is effectively suppressed and the smoke is greatly reduced. The emission of nitrogen oxides in the gas.

It is understandable that the combustion assembly 100 of the present application is sequentially configured with a flue gas ejector, a burner 30 and a flue gas return pipe 50 in the flow direction of the airflow, thereby achieving the purpose of secondary ejection and secondary mixing, and finally obtains The uniformly mixed combustion gas realizes the flameless combustion of the combustion gas under oxygen-lean conditions, producing a relatively low-temperature flame and reducing the emission of nitrogen oxides.

In short, in the combustion assembly 100 of the embodiment of the present application, after premixing the flue gas and fuel gas in the flue gas ejector, they are introduced into the combustor 30, and at the same time, combustion-supporting air is introduced, so that the combustion gas is flameless Way to burn, reducing the emission of nitrogen oxides.

In some embodiments of the present application, as shown in FIG. 1 and FIG. 2, the flue gas ejector is sealed to the gas nozzle 10 so as to isolate the air when the gas and flue gas are premixed in the flue gas ejector. That is, the flue gas ejector is isolated from the outside air source, and air is not introduced into the flue gas ejector. In this way, it is ensured that the gas and flue gas in the flue gas ejector are controlled in an appropriate ratio for premixing, and the gas and smoke The gas is thoroughly mixed and uniform.

Optionally, a flow regulating valve 60 is provided on the flue gas return pipe 50 to adjust the flue gas return flow. The flow control valve 60 regulates the amount of smoke entering the smoke ejector. As a result, it is ensured that an appropriate amount of smoke is obtained in the smoke ejector, and the intake ratio of smoke and gas is effectively adjusted.

Wherein, the end of the flue gas return pipe 50 that is connected to the burner 30 is the smoke taking end, and the end of the flue gas return pipe 50 that is connected to the smoke ejector is the ejection end. That is, the flue gas generated by the burner 30 is introduced into the flue gas return pipe 50 through the smoke-taking end, and the flue gas is released into the flue gas ejector through the emission end. In other words, the flue gas return pipe 50 is a communication pipe connecting the burner 30 and the flue gas ejector. The on-off and opening of the flue gas return pipe 50 determine the amount of flue gas entering the flue gas ejector.

In an alternative embodiment, as shown in FIG. 1, a strong exhaust fan 71 is provided between the smoke extraction end of the flue gas return pipe 50 and the burner 30, and the air outlet of the strong exhaust fan 71 and the smoke extraction end of the flue gas return pipe 50 are provided. Connected. That is, the flue gas in the combustor 30 is drawn out by the forced exhaust fan 71, and a part of the flue gas enters the flue gas return pipe 50 from the fume extraction end, and is then directed into the flue gas ejector to mix with the gas.

In an alternative embodiment, as shown in FIG. 2, the outlet of the flue gas ejector and the air inlet of the combustor 30 are provided with a strong blower, and the air outlet of the strong blower is connected with the outlet of the flue gas ejection pipe to connect to the burner 30 The air inlet provides air. In this way, the smoke gas is introduced into the combustor 30, and the air is drawn into the burner 30 through the air injection port 40 under the suction of the strong blower.

In a further optional example, a smoke collecting hood 80 is provided between the smoke taking end of the flue gas return pipe 50 and the burner 30, and the smoke taking end is in communication 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 drawn out by the forced exhaust fan 71, and part of the flue gas flows back through the flue gas return pipe 50 Into the flue gas ejector, participate in the secondary combustion. Among them, in some embodiments, the forced exhaust fan 71 is arranged on the smoke collecting hood 80.

It can be understood that the flue gas flows into the flue gas ejector after cooling down through the fume collecting hood 80 and the flue gas return pipe 50. In this way, the flue gas can be effectively cooled before entering the combustor 30, so that the reaction temperature of the combustion gas is relatively low, and the lower temperature and oxygen-poor reaction gas is more unfavorable to the production of nitrogen oxides. Thereby effectively reducing harmful gas emissions.

In an alternative example, the inventor found that when the mixing ratio of flue gas and gas in the flue gas ejector is controlled between 1:1 and 10:1, the combustor 30 emits less harmful gas. That is, the content of smoke in a unit of smoke gas is greater than or equal to the content of fuel gas. For example, the mixing ratio of smoke and 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 understandable that the above is only illustrative and not a limitation on the mixing ratio of flue gas and gas. The mixing ratio of flue gas and gas is also It may be other ratios not shown, as long as it is within the above-mentioned interval.

1 and 2, the outlet diameter of the flue gas ejector is smaller than the inlet pipe diameter of the combustor 30. That is, the flue gas flow channel of the flue gas ejector is smaller than that of the combustor 30. That is to say, during the flow of the flue gas, the unit flow area changes from small to large, and the sudden change of the unit flow area can be further Promote the mixing degree of flue gas and fuel gas, ensure that the combustion gas is fully burned, and reduce the emission of harmful gases.

In an alternative embodiment, the distance between the flue gas ejector and the inlet of the burner 30 is less than 10CM. In other words, the flue gas ejector and the inlet of the burner 30 can be arranged at intervals to form an air ejection port 40. At this time, the distance d between the flue gas ejector and the inlet of the burner 30 is between 0-10 cm. Between, for example, 1 cm, 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm or 10 cm. Alternatively, the outlet of the gas ejector 20 may also be provided with a smoke pipe, which extends into the burner 30, and a plurality of air ejection ports 40 are formed on the pipe wall of the smoke pipe.

The advantage of using the air injection port 40 to introduce the combustion-supporting air is that the combustion-supporting air can be divided into multiple small airflows and introduced into the mixed gas of the fuel gas and the flue gas, thereby further improving the uniformity of the mixing of the flue gas, the fuel gas and the combustion-supporting air.

In an alternative example, the flue gas return pipe 50 is located outside the combustor 30 and extends from top to bottom. That is to say, the return flue gas pipe and the burner 30 are arranged separately, so that almost no heat exchange occurs between the burner 30 and the flue gas return pipe 50, thereby making the flue gas temperature in the flue gas return pipe 50 better. Cool down well, so that flue gas with proper temperature can be delivered to the flue gas ejector.

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

In a further optional example, the inventor found in his research that when the temperature of the flue gas is too high, the harmful gas emitted by the burner 30 is higher than that during normal combustion (that is, when the flue gas is not introduced). Therefore, for The temperature control of flue gas is very important. In the present application, a flow regulating valve 60 and a thermostat 90 are provided on the flue gas return pipe 50. When the temperature controller 90 detects that the temperature of the flue gas is higher than the set value, the flow regulating valve 60 is closed and the flue gas return pipe 50 Stop delivering flue gas to the flue gas ejector. In this way, when the temperature of the flue gas is too high, the delivery of flue gas to the flue gas ejector is stopped.

The wall-hung boiler according to the embodiment of the present application includes the combustion assembly 100 of the above-mentioned embodiment. Since the combustion assembly 100 according to the embodiment of the present application emits less nitrogen and oxygen compounds, the pollution to the environment is reduced. Therefore, the wall-hung boiler according to the embodiments of the present application has low pollution, is safe and environmentally friendly.

In the description of this specification, descriptions with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean specific features described in conjunction with the embodiment or example , The structure, materials, or characteristics are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above-mentioned terms does not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner.

Although the embodiments of this application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the application. Those of ordinary skill in the art will not depart from the principle and purpose of this application. Under the circumstances, changes, modifications, substitutions and modifications can be made to the above-mentioned embodiments within the scope of the present application.

Claims

A combustion assembly, characterized in that it comprises:

A gas nozzle, connected to an external gas source, to provide gas to the combustion equipment;

A flue gas ejector, which is in communication with the gas nozzle;

A burner, the air inlet of the burner is in communication with the outlet of the flue gas ejector, and an air ejector is provided between the burner inlet and the outlet of the flue gas ejector;

A flue gas return pipe, one end of the flue gas return pipe is in communication with the burner, and the other end is in communication with the flue gas ejector, so as to divert the flue gas generated by the burner to the flue gas ejector Premix with gas.
The combustion assembly according to claim 1, wherein the flue gas ejector is in sealed connection with the gas nozzle, so that when the gas and flue gas are premixed in the flue gas ejector Isolate the air.
The combustion assembly according to claim 2, wherein a flow regulating valve is provided on the flue gas return pipe to adjust the flue gas return flow.
The combustion assembly according to any one of claims 1 to 3, wherein one end of the flue gas return pipe communicating with the burner is a smoke taking end, and the flue gas return pipe communicates with the flue gas ejector One end is the ejection end.
The combustion assembly according to claim 4, wherein a strong exhaust fan is arranged between the smoke taking end of the flue gas return pipe and the burner, and the air outlet of the strong exhaust fan is connected to the flue gas return The smoking end of the pipe is connected.
The combustion assembly according to claim 4, wherein the outlet of the flue gas ejector and the inlet of the combustor are provided with a strong blower, and the air outlet of the strong blower and the flue gas ejection pipe The outlet is connected to provide air to the burner inlet.
The combustion assembly according to any one of claims 4-6, wherein a smoke collecting hood is provided between the smoke taking end of the flue gas return pipe and the burner, and the smoke taking end is connected to the The smoke collecting hood is connected.
The combustion assembly according to any one of claims 1 to 7, wherein the mixing ratio of flue gas and fuel gas in the flue gas ejector is 1:1-10:1.
The combustion assembly according to any one of claims 1 to 8, wherein the outlet diameter of the flue gas ejector is smaller than the inlet pipe diameter of the burner.
The combustion assembly according to any one of claims 1-9, wherein the distance between the flue gas ejector and the burner inlet is less than 10CM.
The combustion assembly according to any one of claims 1 to 10, wherein the flue gas return pipe is located outside the burner and extends from top to bottom.
The combustion assembly according to claim 11, wherein the flue gas return pipe is a corrugated metal pipe.
The combustion assembly according to claim 3, wherein the flue gas return pipe is provided with a flow regulating 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 regulating valve is closed, and the flue gas return pipe stops delivering flue gas to the flue gas ejector.
A wall-hung boiler, characterized by comprising the combustion assembly according to any one of claims 1-6 or 8-13.