CN103063703A - Experimental method and device for realizing low NOX stable combustion of gaseous fuel - Google Patents

Abstract

The invention belongs to the field of gas fuel combustion experiments, in particular to an experimental method and device for realizing stable combustion of gas fuel with low _NOx . Several individual combustion units with the same structure are arranged on the burner outlet end face of the burner; the individual combustion units are composed of a central fuel nozzle and obliquely arranged air nozzles surrounding the fuel nozzle. In the experiment, dilute fuels such as _N2 can be mixed into the fuel at the same time to reduce the combustion temperature and achieve low _NOx combustion; the air nozzles arranged obliquely can generate swirling airflow due to their tangential velocity to achieve good mixing of air and gaseous fuel ;Through the opening and blocking of different fuel nozzle channels, different combustion units can operate independently or jointly, thereby adjusting the combustion intensity of the overall flame in the burner; placing temperature measuring points on the wall of the nozzle outlet to realize online temperature measurement; A flue gas sampling channel is designed at the exit of the chamber to realize online measurement and analysis of tail flue gas.

Description

Experimental method and device for realizing low NOX stable combustion of gaseous fuel

technical field

The invention belongs to the field of gas fuel combustion equipment, and in particular relates to an experimental method and device for realizing stable combustion of gas fuel with low _NOx .

Background technique

With the continuous development of the economy, China's energy and environmental problems have become more and more prominent, facing the current situation of low average energy utilization rate and serious environmental pollution. The research on various forms of clean coal power generation technology has been greatly developed in our country, among which integrated gasification combined cycle (IGCC) power generation technology is an advanced technology with development potential. In order to prevent backfire and other problems in traditional gas turbines, the combustion chamber generally adopts diffusion combustion technology, but the flame temperature of diffusion combustion is high, and the heat released by the reaction is difficult to transfer out quickly, resulting in relatively low thermal _NOx emissions generated by combustion. high. The main components of gas turbine fuel in IGCC technology are carbon monoxide and hydrogen, and the temperature of the adiabatic flame is high. The _NOx generated during the combustion process will pollute the environment. On the other hand, with the wide application of natural gas fuel in China, the combustion of natural gas also faces the problem of NO _X pollutant emission. At the same time, when the gaseous fuel (the main components are carbon monoxide and hydrogen) is burned, due to its active chemical properties and high flame temperature, the temperature of the wall surface of the nozzle will be too high, and the nozzle will be burnt out in severe cases.

Invention patent 200810117256.5 achieves the dispersion of the flame surface by injecting fuel through multiple micro-holes to achieve the purpose of reducing NOx emissions. However, the related technology is not very mature, and a large number of related experiments need to be carried out to understand its combustion characteristics, but there is currently a lack of experimental equipment in this regard.

Contents of the invention

The object of the present invention is to propose an experimental method and device for realizing stable combustion of gaseous fuel with low _NOx .

The experimental method for realizing stable combustion of gaseous fuel with low _NOx is specifically as follows: multiple groups of swirling air are used to wrap the combustion unit of gaseous fuel, and air nozzles are arranged around the gaseous fuel nozzle in each unit to jointly form a combustion unit; The combustion units of the group burn independently, which reduces the local heat load; in the experiment, N ₂ diluted fuel is mixed into the fuel to reduce the combustion temperature and achieve low _NOx combustion; through the opening and blocking of different fuel nozzle channels, each The combustion units can operate individually or in combination, thereby adjusting the combustion intensity of the overall flame in the burner.

The device for realizing stable combustion of gaseous fuel with low NO _x includes a burner, a combustion chamber, a fuel chamber and an air chamber; several separate combustion units with the same structure are arranged on the burner outlet end face of the burner, and Set several temperature measuring points on the nozzle outlet wall surface; the single combustion unit is composed of a fuel nozzle in the center and an air nozzle surrounding the fuel nozzle, wherein the fuel nozzle is arranged vertically, the air nozzle is arranged obliquely, and the air nozzle is arranged along the vertical line of the nozzle opening plane The range of inclination angle is between 10~20o.

The cross section of the combustion chamber is rectangular, and transparent quartz glass windows are installed on three or four walls of the combustion chamber.

A flue gas sampling channel is arranged on the combustion chamber outlet of the combustion chamber to facilitate the sampling and analysis of the flue gas, and the on-line measurement and analysis of the flue gas can be realized through related instruments.

The fuel chamber and the air chamber are located at the lower part of the burner, and the air chamber has a plurality of air inlets.

The individual combustion units are arranged in a polygonal array, or in a circular array, or in an elliptical array.

There are 3 to 5 temperature measuring points on the wall surface of the outlet of the nozzle, and the online temperature measurement is realized through thermocouples welded at the measuring points and supporting software.

The beneficial effects of the present invention are:

Through the dispersion of the flame surface, the purpose of reducing the combustion temperature and low NO _X combustion can be achieved; at the same time, through the adjustment of different nozzle groups, the combustion intensity of the overall flame in the burner can be adjusted.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the device of the present invention.

Fig. 2 is a top view of the outlet end face of the burner in Fig. 1 .

Fig. 3 is an enlarged schematic view and a partial cross-sectional view of a single combustion unit in Fig. 2 .

Labels in the figure:

1-burner, 2-combustion chamber, 3-fuel chamber, 4-air chamber, 11-burner outlet end face, 12-individual combustion unit, 13-nozzle outlet wall temperature measuring point, 121-air nozzle, 122 - fuel nozzle, 21 - quartz glass window, 22 - combustion chamber outlet, 23 - flue gas sampling channel, 31 - fuel inlet, 41 - air inlet.

Detailed ways

The present invention provides an experimental method and device for realizing stable combustion of gaseous fuel with low NO _X. The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

The experimental method for realizing stable combustion of gaseous fuel with low NO _x is specifically as follows: using swirling air to wrap gaseous fuel for combustion, air nozzles are arranged around each gaseous fuel nozzle to form a micro-mixed combustion unit; in the experiment, fuel Dilute fuels such as N ₂ are mixed into the fuel to reduce the combustion temperature and achieve low _NOx combustion; through the opening and blocking of different fuel nozzle channels, each combustion unit can operate independently or jointly, thereby adjusting the overall flame in the burner burning intensity.

Realize the device of described method, as shown in Figure 1:

The combustion device is composed of main components such as a burner 1, a combustion chamber 2, a fuel chamber 3 and an air chamber 4; several separate combustion units 12 with the same structure are arranged on the burner outlet end face 11 of the burner 1; The unit 12 is composed of a fuel nozzle 122 in the center and an air nozzle 121 surrounding the fuel nozzle 122, wherein the fuel nozzle 122 is arranged vertically and the air nozzle 121 is arranged obliquely. Multiple individual combustion units 12 ensure that the flame surface is dispersed, so that the heat load is not too concentrated, the combustion temperature is reduced, and low NOx combustion is realized; the air nozzle 122 can generate a swirling air flow to achieve good mixing of air and gas fuel to achieve stable combustion And the purpose of burnout; through the opening and blocking of different fuel nozzles 121 channels, different combustion units 12 can operate independently or jointly, thereby adjusting the combustion intensity of the overall flame in the burner. A temperature measuring point 13 is set on the burner outlet end surface 11 of the burner 1 to realize online measurement of the wall surface temperature during combustion.

The cross-section of the combustion chamber 2 is square, and transparent quartz glass windows 21 are installed on three or four walls of the combustion chamber 2, through which the combustion situation of the flame in the combustion chamber can be observed, so as to facilitate the starting of combustion and the observation of combustion conditions; A flue gas sampling channel 23 is designed in the bypass of the outlet 22 of the combustion chamber to facilitate the sampling and analysis of the flue gas, and the on-line measurement and analysis of the tail flue gas is realized through related instruments. The bottom of the burner 1 has two chambers, an air chamber 4 and a fuel chamber 3, respectively, and the air and fuel enter the combustion chamber 2 through their respective nozzles and are mixed in the combustion chamber 2. The uniform distribution of fuel between multiple fuel nozzles in the combustion chamber 2 is realized by increasing the height of the fuel chamber 3 and adding porous fillers in the fuel chamber 3; the uniform distribution of air among the multiple air nozzles in the combustion chamber 2 is It is realized by arranging a plurality of air inlets 41 in the air chamber 4 . During operation, fuel enters the fuel chamber 3 through the fuel inlet 31 , and air enters the air chamber 4 through the air inlet 41 .

The invention is not limited to the specific examples listed above. Obviously, the present invention can also have many modifications, and any changes within the meaning and scope equivalent to the claims should be considered to be included in the scope of the claims.

Claims (7)

1. realize the low NO of gaseous fuel for one kind _XThe experimental technique of smooth combustion is characterized in that, adopts the fuel element of many group rotational flow air parcel gaseous fuels, around the gas fuel nozzle air nozzle is set all in each unit and jointly forms fuel element; By many groups fuel element independent burning separately, reduced local heat load; In the experiment, in fuel, sneak into N ₂Fuel diluted reaches the purpose that reduces temperature of combustion, realizes low NO _XBurning; By the opening and stopping up of different fuel nozzle passage, each fuel element can isolated operation or cooperation, thereby adjusts the combustion intensity of whole flame in the burner.

2. realize the low NO of gaseous fuel for one kind _XThe experimental provision of smooth combustion, comprise burner (1), firing chamber (2), fuel chamber (3) and air chamber (4), it is characterized in that, the identical independent fuel element (12) of several structures is set on the burner outlet end face (11) of described burner (1), and several jet expansion wall surface temperature measuring points (13) are set; Separately fuel element (12) forms by the fuel nozzle (122) at center with around the air nozzle (121) of fuel nozzle (122), wherein, fuel nozzle (122) is vertically to arrange, air nozzle (121) is for being in tilted layout, air nozzle (121) along jet hole plane perpendicular line range of tilt angles between 10 ~ 20o.

3. a kind of realization gaseous fuel according to claim 2 hangs down NO _XThe device of smooth combustion is characterized in that, the xsect of described firing chamber (2) is rectangle, three of (2) or four transparent quartz windows (21) of walls installation in the firing chamber.

4. a kind of realization gaseous fuel according to claim 2 hangs down NO _XThe device of smooth combustion is characterized in that, on the combustor exit (22) of described firing chamber (2) smoke sampling passage (23) is set, and is convenient to the smoke sampling analysis, by the on-line measurement analysis of pertinent instruments realization to flue gas.

5. a kind of realization gaseous fuel according to claim 2 hangs down NO _XThe device of smooth combustion is characterized in that, described fuel chamber (3) and air chamber (4) are positioned at the bottom of burner (1), and air chamber (4) possesses a plurality of air ins (41).

6. a kind of realization gaseous fuel according to claim 2 hangs down NO _XThe device of smooth combustion is characterized in that, described independent fuel element (12) is the polygon arranged in arrays, or the circular array layout, or oval-shaped array is arranged.

7. a kind of realization gaseous fuel according to claim 2 hangs down NO _XThe device of smooth combustion is characterized in that, described jet expansion wall surface temperature measuring point (13) is 3 ~ 5, and the thermopair by being welded on the measuring point place and supporting software are realized the on-line measurement to temperature.

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