A low nitrogen gas burner suitable for medium and low calorific value fuels

Abstract

The present invention discloses a low-nitrogen gas burner suitable for medium and low calorific value fuels, comprising a central fuel cylinder, a swirl wind cylinder, a main fuel outer cylinder and a burner case shell which are sequentially distributed from the inside to the outside; a swirl disk is arranged at the outlet of the inner swirl wind area, a main fuel inlet is arranged at one end of the main fuel collecting ring, and a plurality of main fuel nozzles are arranged at the other end of the main fuel collecting ring; a combustion-supporting air inlet is arranged on the side of the burner case shell, wherein the outlet of the medium and low calorific value gas fuel pipeline is connected with the central fuel inlet and the main fuel inlet, and the combustion-supporting air duct is connected with the swirl disk and the outer direct air area, and the burner has the characteristics of high combustion efficiency and low nitrogen oxide emission.

Description

Technical Field

[0001] The invention belongs to the technical field of ultra-low nitrogen clean combustion and relates to a low nitrogen gas burner suitable for medium and low calorific value fuels. Background Art

[0002] In recent years, the demand and price of energy have continued to rise, while the energy supply is relatively tight. The energy gap problem has become increasingly prominent. At the same time, global environmental problems have continued to emerge, such as climate warming, acid rain and photochemical smog, making environmental issues increasingly concerned by society. At present, the world's energy supply mainly relies on fossil energy, and combustion is its main way of energy conversion. It converts the chemical energy of fuel into thermal energy. The energy obtained by burning mineral fuels accounts for more than 90% of the world's total energy consumption. The task of energy conservation and emission reduction is arduous.

[0003] Gas fuel has the characteristics of high combustion efficiency and low pollution emission, so it is widely used in industrial furnaces (kilns) and boilers in the power, chemical, metallurgical, building materials and other industries as a clean energy. As a key equipment, the research on gas burners has made continuous progress. However, the research on it is mainly focused on improving the performance of the burner. The attention paid to pollutant control is far from enough.

[0004] Since the standard was issued on April 1, 2015, the NOx emission mass concentration control standard for all gas boilers (including medium and low calorific value gas boilers) has been reduced to 30mg / m 3 (Standard state, 3.5% O2). Traditional medium and low calorific value gas burners alone can no longer meet emission requirements. Therefore, it is urgent to develop medium and low calorific value low NOx gas burners to meet the latest environmental protection standards.

[0005] At present, there is little research on medium-low calorific value and low-nitrogen gas burners. With the increasingly stringent environmental protection standards, energy-saving and environmental protection transformation of gas boilers is imminent. Therefore, there is an urgent need for a medium-low calorific value gas burner with high combustion efficiency and low nitrogen oxide emissions. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a low-nitrogen gas burner suitable for medium and low calorific value fuels, which has the characteristics of high combustion efficiency and low nitrogen oxide emissions.

[0007] To achieve the above-mentioned purpose, the low-nitrogen gas burner suitable for medium and low calorific value fuels described in the present invention comprises a central fuel cylinder, a swirl wind cylinder, a main fuel outer cylinder and a burner casing, which are sequentially arranged from the inside to the outside, wherein a central fuel channel is formed in the central fuel cylinder, an annular inner swirl wind area is formed between the central fuel cylinder and the swirl wind cylinder, an annular main fuel gas collecting ring is formed between the swirl wind cylinder and the main fuel outer cylinder, an annular outer direct air area is formed between the main fuel outer cylinder and the burner casing, a central fuel inlet is provided at one end of the central fuel cylinder, and a plurality of central fuel gun nozzles are provided at the other end of the central fuel cylinder;

[0008] A swirl disk is arranged at the outlet of the inner swirl wind area, a main fuel inlet is arranged at one end of the main fuel collecting ring, a main fuel nozzle is arranged at the other end of the main fuel collecting ring, and a plurality of main fuel nozzles are arranged on the main fuel nozzle;

[0009] A combustion air inlet is provided on the side of the burner box shell, wherein the outlet of the medium and low calorific value gas fuel pipeline is connected with the central fuel inlet and the main fuel inlet, and the combustion air duct is connected with the swirl disk and the external direct air area.

[0010] A first regulating device is arranged between the combustion-supporting air duct and the swirl disk.

[0011] A second regulating device is arranged between the combustion-supporting air duct and the external direct air region.

[0012] Each central fuel gun nozzle is respectively arranged on the end face and the side face of the central fuel barrel, wherein each central fuel gun nozzle arranged on the end face of the central fuel barrel is an elliptical structure, and each central fuel gun nozzle arranged on the side face of the central fuel barrel is a rectangular nozzle.

[0013] There are two main fuel nozzles, wherein the size of the first main fuel nozzle is smaller than the size of the second main fuel nozzle, and both main fuel nozzles are rectangular structures, wherein the distance between the second main fuel nozzle and the axis of the main fuel collecting ring is smaller than the distance between the first main fuel nozzle and the axis of the main fuel collecting ring.

[0014] The size of the first main fuel nozzle is 1 / 2 the size of the second main fuel nozzle.

[0015] The present invention has the following beneficial effects:

[0016] During specific operation, the low-nitrogen gas burner suitable for medium and low calorific value fuels described in the present invention sprays out combustion-supporting air in two stages through the swirl wind cylinder and the burner housing, and the medium and low calorific value gas fuels are mixed with the combustion-supporting gas in two stages through the central fuel cylinder and the main fuel outer cylinder, so that the medium and low calorific value gas fuels and the combustion-supporting air are evenly mixed to control the generation of NOx. At the same time, the medium and low calorific value gas fuels are arranged between the central fuel channel and the swirl wind and direct wind, and the nozzles of each central fuel gun are arranged radially and axially to realize diffuse mixed combustion of the central fuel to enhance the stable combustion capability, so that the burner has the characteristics of high combustion efficiency and low nitrogen oxide emissions, and has a simple structure and low cost.

[0017] Furthermore, there are two main fuel nozzles, wherein the fuel sprayed from one main fuel nozzle is mixed with the swirl wind and burned, and the fuel sprayed from the other main fuel nozzle is mixed with the outer circle direct current wind and burned, thereby realizing fuel grading, improving combustion efficiency and reducing nitrogen oxide emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention;

[0019] Figure 2 is a side view of the present invention;

[0020] Figure 3 It is a structural schematic diagram of the central fuel gun nozzle 1 in the present invention;

[0021] Figure 4 It is a schematic structural diagram of the main fuel nozzle 3 in the present invention.

[0022] Among them, 1 is the central fuel gun nozzle, 2 is the swirl disk, 3 is the main fuel nozzle, 4 is the external direct air flow area, 5 is the main fuel inlet, 6 is the central fuel inlet, 7 is the second regulating device, 8 is the first regulating device, 9 is the central fuel cylinder, 10 is the main fuel outer cylinder, 11 is the swirl wind cylinder, 12 is the burner box shell, and 13 is the combustion-supporting air duct. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0024] refer to Figure 1 , Figure 2 , Figure 3 and Figure 4The low-nitrogen gas burner suitable for medium- and low-calorific value fuels of the present invention comprises a central fuel cylinder 9, a swirl wind cylinder 11, a main fuel outer cylinder 10 and a burner case shell 12, which are arranged in sequence from the inside to the outside. A central fuel channel is formed in the central fuel cylinder 9, an annular inner swirl wind area is formed between the central fuel cylinder 9 and the swirl wind cylinder 11, an annular main fuel gas collecting ring is formed between the swirl wind cylinder 11 and the main fuel outer cylinder 10, and an annular outer direct air flow area 4 is formed between the main fuel outer cylinder 10 and the burner case shell 12. A central fuel cylinder 9 is provided at one end. A central fuel inlet 6 is provided, and a plurality of central fuel gun nozzles 1 are provided at the other end of the central fuel cylinder 9; a swirl disk 2 is arranged at the outlet of the inner swirl wind area, a main fuel inlet 5 is provided at one end of the main fuel collecting ring, and a main fuel nozzle 3 is provided at the other end of the main fuel collecting ring, and a plurality of main fuel nozzles are provided on the main fuel nozzle 3; a combustion-supporting air inlet is provided on the side of the burner box shell 12, wherein the outlet of the medium and low calorific value gas fuel pipeline is connected with the central fuel inlet 6 and the main fuel inlet 5, and the combustion-supporting air duct 13 is connected with the swirl disk 2 and the outer direct air area 4.

[0025] A first regulating device 8 is arranged between the combustion-supporting air duct 13 and the swirl disk 2 , and a second regulating device 7 is arranged between the combustion-supporting air duct 13 and the external direct air region 4 .

[0026] Each central fuel gun nozzle 1 is respectively arranged on the end face and side face of the central fuel barrel 9, wherein each central fuel gun nozzle 1 arranged on the end face of the central fuel barrel 9 is an elliptical structure, and each central fuel gun nozzle 1 arranged on the side face of the central fuel barrel 9 is a rectangular nozzle.

[0027] There are two main fuel nozzles, wherein the size of the first main fuel nozzle is smaller than that of the second main fuel nozzle, and both main fuel nozzles are rectangular structures, wherein the distance between the second main fuel nozzle and the axis of the main fuel collecting ring is smaller than the distance between the first main fuel nozzle and the axis of the main fuel collecting ring, and the size of the first main fuel nozzle is 1 / 2 of the size of the second main fuel nozzle.

[0028] The axial position and angle of the swirl blade of the swirl disk 2 are adjustable. The axial position is 50-200mm away from the outer edge of the burner throat. The adjustment range of the swirl blade angle is 15°-90°. The fuel is divided into two levels, and the combustion air is divided into two levels, both of which can be quantitatively adjusted.

[0029] The super-mixed state is achieved by staging medium and low calorific value gas fuel and combustion air to achieve the purpose of reducing nitrogen oxides to the greatest extent. At the same time, high load regulation, furnace and fuel adaptability are achieved by adjusting the gas fuel amount and air volume at each level. In specific implementation, the present invention provides an economic transformation technology route for the out-of-stock of medium and low calorific value gas boilers. By relying on the burner, the nitrogen oxide emission of low calorific value gas boilers can be reduced to 30mg / m3 (standard state, 3.5% O2) or less, medium calorific value gas fuel gas boiler with flue gas recirculation technology, the nitrogen oxides are controlled at 30mg / m 3 The following meet the latest environmental standards.

Claims

1. A low nitrogen gas burner suitable for medium and low calorific value fuels, characterized in that: The invention comprises a central fuel cylinder (9), a swirl wind cylinder (11), a main fuel outer cylinder (10) and a burner casing (12) which are sequentially arranged from the inside to the outside, wherein a central fuel channel is formed in the central fuel cylinder (9), an annular inner swirl wind area is formed between the central fuel cylinder (9) and the swirl wind cylinder (11), an annular main fuel air collecting ring is formed between the swirl wind cylinder (11) and the main fuel outer cylinder (10), an annular outer direct air area (4) is formed between the main fuel outer cylinder (10) and the burner casing (12), a central fuel inlet (6) is arranged at one end of the central fuel cylinder (9), and a plurality of central fuel gun nozzles (1) are arranged at the other end of the central fuel cylinder (9); A swirl disk (2) is arranged at the outlet of the inner swirl wind area, a main fuel inlet (5) is arranged at one end of the main fuel air collecting ring, a main fuel nozzle (3) is arranged at the other end of the main fuel air collecting ring, and a plurality of main fuel nozzles are arranged on the main fuel nozzle (3); A combustion air inlet is provided on the side of the burner housing (12), wherein the outlet of the medium and low calorific value gas fuel pipeline is connected to the central fuel inlet (6) and the main fuel inlet (5), and the combustion air duct (13) is connected to the swirl disk (2) and the external direct air flow area (4); Each central fuel gun nozzle (1) is respectively arranged on the end surface and the side surface of the central fuel barrel (9), wherein each central fuel gun nozzle (1) arranged on the end surface of the central fuel barrel (9) is an elliptical structure, and each central fuel gun nozzle (1) arranged on the side surface of the central fuel barrel (9) is a rectangular nozzle; The number of main fuel nozzles is two, wherein the size of the first main fuel nozzle is smaller than the size of the second main fuel nozzle, and both main fuel nozzles are rectangular structures, wherein the distance between the second main fuel nozzle and the axis of the main fuel collecting ring is smaller than the distance between the first main fuel nozzle and the axis of the main fuel collecting ring; The fuel sprayed from one main fuel nozzle is mixed with the swirl wind and burned, and the fuel sprayed from the other main fuel nozzle is mixed with the outer circle direct current wind and burned.

2. The low-nitrogen gas burner suitable for medium and low calorific value fuels according to claim 1 is characterized in that: A first regulating device (8) is arranged between the combustion-supporting air duct (13) and the swirl disk (2).

3. The low-nitrogen gas burner suitable for medium and low calorific value fuels according to claim 2 is characterized in that: A second regulating device (7) is arranged between the combustion-supporting air duct (13) and the external direct air flow area (4).

4. The low-nitrogen gas burner suitable for medium and low calorific value fuels according to claim 1 is characterized in that: The size of the first main fuel nozzle is 1 / 2 the size of the second main fuel nozzle.

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