CN113757668B - A spiral ring rib water-cooled cold flame gas burner - Google Patents

Abstract

The invention discloses a spiral ring rib water-cooling type cold flame gas burner, which comprises a surface combustion device and a three-stage water-cooling circulating device: the surface combustion device comprises a plurality of layers of spiral annular ribs, the plurality of layers of spiral annular ribs are arranged at a certain angle with the axis of the combustor to form a spiral step-shaped isobaric air inlet chamber, and ignition gun holes/central secondary air pipes are arranged on the inner sides of the plurality of layers of spiral annular ribs; the three-stage water-cooling circulating device comprises a water inlet collecting tank and a water outlet collecting tank, the water inlet collecting tank and the water outlet collecting tank are respectively connected with the annular cooling water pipes to form a closed water circulation loop, the annular cooling water pipes are arranged on the spiral annular ribs in a penetrating mode to form a first-stage water-cooling surface, the low U-shaped pipe bundles and the high U-shaped pipe bundles are arranged inside the combustion chamber to form a second-stage water-cooling surface and a third-stage water-cooling surface, and the whole forming body is a spheroid cold flame combustion surface. The invention ensures the stability, high efficiency, cleanness and safety of gas fuel during combustion, and can realize water cooling of the flame surface and the closed circulation loop formed by cooling pipelines.

Description

A spiral ring rib water-cooled cold flame gas burner

technical field

The invention belongs to the technical field of cold flame gas burners, in particular to a water-cooled cold flame gas burner with spiral ring ribs.

Background technique

As a kind of clean energy, natural gas has the advantages of high combustion efficiency, low pollutant control cost and less pollutant emission. Natural gas will still produce some atmospheric pollutants such as nitrogen oxides in the process of combustion. According to its source, it is mainly divided into Thermal type, fast type and fuel type, in which the generation of fuel type and fast type is almost negligible, and the thermal type _NOx accounts for more than 90% of all nitrogen oxide emissions.

The key to controlling the emission of NOx: one is to control the formation of nitrogen oxides, and the other is to control the reduction of nitrogen oxides that have been produced to N ₂ . Controlling the formation of nitrogen oxides is mainly to control the combustion temperature, and reduce the emission of nitrogen oxides by lowering the combustion temperature. The main influencing factors of thermal NO _x generation are combustion temperature, oxygen concentration and residence time of reactants. When the combustion temperature is higher than 1300 ℃, the reaction rate will increase by 5 to 6 times, and the amount of nitrogen oxides generated at this time increases exponentially. Due to the high calorific value of natural gas, the combustion temperature can usually be as high as 2000K or more. When the combustion temperature is higher than 1300°C, the reaction rate will increase by 6 to 7 times for every 100°C increase in temperature, resulting in the original nitrogen oxides. Emissions are increasing exponentially. Although domestic low-nitrogen combustion technologies for gas-fired boilers have been developed to some extent, such as staged combustion, flue gas recirculation, lean-burn premixing, water-cooling premixing, etc., some technologies still have high costs, poor effects, and are not suitable for high pressure and Disadvantages of supercritical boilers, etc.

SUMMARY OF THE INVENTION

In order to overcome the above technical problems, the purpose of the present invention is to provide a spiral ring rib water-cooled cold flame gas burner, which can realize equal pressure intake, uniform gas, low temperature and low NOx surface combustion, and can effectively prevent backfire at the same time , to ensure the stability, efficiency, cleanliness and safety of gas fuel combustion, the cooling pipeline forms a closed circulation loop, and can also achieve water cooling on the flame surface.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A spiral annular rib water-cooled cold flame gas burner, comprising a surface combustion device and a three-stage water-cooled circulation device:

The surface combustion device includes a spiral ring rib 8, and the spiral ring rib 8 is provided with multiple layers around the ignition gun hole/central secondary air duct 3. The multi-layer spiral ring rib 8 is arranged at an angle to the burner axis to form a spiral. Step-shaped isobaric air intake chamber 11;

The three-stage water-cooling circulation device includes an inlet header 2 and an outlet header 4. The inlet header 2 and the outlet header 4 are respectively connected with an annular cooling water pipe 5 to form a closed water circulation loop, and the annular cooling water pipe 5 runs along the burner. The axis runs through the spiral ring rib 8 to form the first-stage water-cooling surface. The combustion chamber 7 is provided with a low U-shaped tube bundle 10 and a high U-shaped tube bundle 9. The low U-shaped tube bundle 10 and the high U-shaped tube bundle 9 are arranged in a criss-crossed height. , constitute the second-level water-cooling surface and the third-level water-cooling surface, and form a sphere-like cold flame combustion surface as a whole, and the combustion chamber 7 is cylindrically wrapped outside the U-shaped tube bundle.

The low U-shaped tube bundles 10 and the high U-shaped tube bundles 9 are extensions of the annular cooling water pipes 5, and the inlets and outlets are connected to the semi-circular water outlet header 4 and the water inlet header 2, which together constitute the water cooling circulation structure of the device.

The annular cooling water pipes 5 are obliquely placed on the spiral annular rib 8 at equal intervals in the circumferential direction, and the inclination angle is the same as the inclination angle of the spiral annular rib 8 structure.

The water inlet header 2 and the water outlet header 4 are both semi-circular structures and are arranged in parallel above the air inlet chamber 11. The annular cooling water pipe 5 includes an annular cooling water pipe 5a and an annular cooling water pipe 5b. Entering from the inlet header 2, it flows through the annular cooling water pipe 5a, the high U-shaped tube bundle 9 and the low U-shaped tube bundle 10, and is collected in the outlet header 4 through the diagonally arranged annular cooling water pipe 5b.

The angles are arranged at 45°-75°.

Beneficial effects of the present invention:

By means of the cooling water pipes arranged in the circumferential direction of the spiral ring rib and the U-shaped tube bundles arranged in a high and low cross, the invention can fully reduce the combustion temperature, ensure the heat exchange efficiency and combustion safety at the same time, realize the uniform surface combustion with low temperature and low NOx, and is suitable for atmospheric boilers , high pressure boilers and supercritical boilers. At the same time, it can also be used as a cooling device in the field of cooling technology, which can fully reduce the temperature of the hot air flow and ensure the safe operation of the heating element.

Description of drawings

Fig. 1 is the front plan view of the present invention.

Figure 2 is a structural diagram of the burner of the present invention.

Figure 3 is a bottom view of the present invention.

Figure 4 is a top view of the present invention.

FIG. 5 is a structural diagram of the water inlet header and the water outlet header of the present invention.

Fig. 6 is the structure diagram of the spiral ring rib of the present invention.

Among them: flange 1, water inlet header 2, ignition gun hole/center secondary air pipe 3, water outlet header 4, annular cooling water pipe 5a, annular cooling water pipe 5b, anti-tempering air inlet micro-channel 6, Combustion chamber 7 , spiral ring rib 8 , high U-shaped tube bundle 9 , low U-shaped tube bundle 10 , intake chamber 11 .

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings.

Referring to Figures 1 to 6, a spiral ring rib water-cooled cold flame gas burner, the main structure of which is that the mixed gas flow is entered from the "step"-shaped mixed gas inlet formed by multiple sets of spiral ring ribs 8 above in Figure 1; The water-cooling pipe 5 is connected with multiple groups of spiral ring ribs 8 by welding to form a ribbed cooling water pipe. The multiple groups of spiral ring ribs 8 are arranged at an angle of θ with the axis of the burner; the annular water-cooling pipe 5 is arranged along the circumferential direction, etc. The spacing is oblique, and the installation angle is the same as the inclination angle of the spiral ring rib 8; the multiple groups of spiral ring ribs 8 and the first-level annular cooling water pipe 5 form an anti-tempering air intake micro-channel 6, and the outlet forms a "step"-shaped combustion plane; The annular water cooling tube 5 is connected with the high U-shaped tube bundle 9 and the low U-shaped tube bundle 10, and the high U-shaped tube bundle 9 and the low U-shaped tube bundle 10 respectively constitute a secondary water cooling and a tertiary water cooling structure; the water inlet header 2 and the water outlet The header 4 is connected to the other end of the annular water cooling tube 5, and the high U-shaped tube bundle 9 and the low U-shaped tube bundle 10 constitute the water circulation system of the cooling device.

The invention can ensure that the mixed gas forms surface combustion on the surface of the burner, and is provided with spiral ring ribs 8. The cooling water pipes installed at equal intervals in the circumferential direction and the cooling pipe bundles arranged at high and low levels can reduce the flame combustion temperature and effectively increase the heat exchange and heat exchange efficiency.

The annular water-cooling pipe 5 and the burner axis are obliquely arranged at an angle θ at equal intervals in the circumferential direction, and the spiral annular rib 8 and the annular cooling water pipe 5 form an anti-tempering air intake micro-channel 6; The multiple sets of helical ring ribs 8 arranged at the corners present the air inlet of the "step"-shaped structure. When the mixed air enters the anti-tempering air inlet micro-channel 6 through the "step"-shaped air inlet surface, the equal pressure air intake is formed to ensure the mixing. The airflow is uniformly inhaled in the flow direction, thereby forming uniform surface combustion at the outlet; the spiral ring rib 8 makes the airflow enter the burner in a rotating state, and the high-turbulence outlet airflow further enhances the low-temperature combustion effect, while helping It is easy to ignite and strengthen combustion; the spiral-up structure makes the flow cross-sectional area gradually decrease along the intake direction, which effectively prevents the premixed combustion from tempering and ensures the safety of the premixed combustion.

Multiple groups of spiral ring ribs 8 arranged at an angle of θ to the axis of the burner, and the annular cooling water pipe 5 penetrate the spiral ring rib 8 to form the first-stage water cooling surface. The connection forms a closed water circulation loop. The high U-shaped tube bundles 9 and the low U-shaped tube bundles 10 are arranged in a crisscross height to form the second and third stages of water cooling. At the same time, the reticulated spherical staggered structure can increase the heat exchange area between the flue gas and the cooling water pipes. Increase the turbulence of combustion and enhance heat transfer. The water-cooling pipeline structure on the reticulated flame surface is a U-shaped circulating tube bundle. The three-stage water cooling forms a sphere-like cold flame as a whole. The multiple water-cooling surface layout fully absorbs the heat of the premixed flame and high-temperature flue gas, effectively reducing its temperature, thereby achieving low-temperature and low-NOx combustion.

The upper end of the annular cooling water pipe 5 is connected to the inlet header 2 and the outlet header 4, and the lower end is connected to the low U-shaped tube bundle 10 and the high U-shaped tube bundle 9. The cooling water in the inlet header is respectively connected from the annular cooling water pipe. 5a enters, and then flows through the U-shaped tube bundle and flows out from the annular cooling water pipe 5b to the diagonal outlet header, which together constitute the cooling water circulation system of the device.

The ignition gun hole/central secondary air duct 3 is welded on the inside of the spiral ring rib 8. When used as the ignition gun hole, it forms a completely premixed surface low temperature combustion; when used as a central secondary air duct, it forms a partially oxygen-depleted premixed low temperature surface. Combustion and oxygen-enriched supplementary combustion avoid the excess air coefficient when the NOx emission of gas fuel combustion is the highest.

The working principle of the present invention is:

The multiple groups of helical annular ribs 8 of the present invention are arranged at an angle of θ (45°<θ<75°) with the axis of the burner, forming a continuous "step"-shaped airflow inlet to ensure uniform and equal pressure intake of the mixed airflow. Multiple groups of spiral ring ribs 8 and the annular water-cooled tube 5 form a tempering-proof air inlet micro-channel 6. When the mixed airflow enters the tempering-proof air inlet micro-channel 6 from the continuous "step" air inlet, the water-cooled tube is surrounded by the tempering-proof air inlet micro-channel 6. 5 Cooling, fully reducing the combustion temperature at the root of the premixed flame and reducing the original emission of nitrogen oxides. At the same time, due to the gradual reduction of the flow cross-sectional area along the airflow direction, the premixed flame cannot be diffused from the combustion chamber to the burner, effectively preventing the premixed flame. Combustion safety hazard that mixed flame is easy to temper, to ensure the safety of combustion. The flue gas generated by the combustion of the flame on the surface of the burner is successively cooled by two-stage water cooling and three-stage water-cooling composed of a low U-shaped tube bundle 10 and a high U-shaped tube bundle 9, which fully absorbs the heat of the high-temperature flue gas and reduces the thermal nitrogen in the flue gas. The formation of oxides makes the low-temperature clean combustion effect better, and the continuous "mountain"-shaped cooling surface structure arrangement increases the airflow turbulence and further enhances the heat exchange effect.

The present invention is provided with a water inlet header 2 and a water outlet header 4, which are respectively connected with the annular water cooling pipes 5, and the high U-shaped tube bundles 9 and the low U-shaped tube bundles 10 constitute the cooling water circulation system of the device. The water tank is a semi-circular ring structure, and all the tubular structures of the present invention adopt pressure-bearing round pipes, which can operate safely under high pressure conditions, have a simple structure, are convenient to manufacture, are suitable for mass production, and can operate in a variety of working environments.

The present invention provides two structural solutions for the burner:

Option 1 arranges the central secondary air duct 3 in the center of the burner to avoid the excess air coefficient when the NOx emission of gas fuel combustion is the highest, and forms partial premixed low-temperature surface combustion with lean oxygen and oxygen-rich supplementary combustion, and the effect of low-nitrogen combustion is better. .

In the second scheme, the ignition hole 3 is arranged in the center of the burner to form a full premixed low temperature surface combustion, and the combustion efficiency is higher.

The specific operation mode of the present invention is:

Before the mixed gas enters the combustion device, the cooling water is firstly passed into the water inlet header 2. After the cooling water forms a water circulation in the device, the mixed gas flows into the anti-tempering air inlet micro-channel 6, and finally ignites. In the specific operation process, the amount of cooling water in the annular cooling water pipe is adjusted according to the actual situation to adjust the combustion flame temperature, so as to ensure the uniform combustion of gas at low temperature and low _NOx in the combustion device.

The above content is only to illustrate the technical idea of the present invention, and it cannot limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention, such as changing the number of cooling water pipes, the spiral ring The rib shape and the like all fall within the protection scope of the claims of the present invention.

Claims (5)

1. The utility model provides a cold flame gas burner of spiral ring rib water-cooling type which characterized in that, includes surface combustion device and tertiary water-cooling circulating device:

the surface combustion device comprises a spiral annular rib (8), the spiral annular rib (8) is provided with a plurality of layers and arranged around an ignition gun hole/a central secondary air pipe (3), and the plurality of layers of spiral annular ribs (8) are arranged at an angle with the axis of the combustor to form a spiral step-shaped isobaric air inlet chamber (11);

tertiary water-cooling circulating device contains into water collection case (2) and goes out water collection case (4), and the collection case of intaking (2) and play water collection case (4) are connected formation closed water circulation return circuit with ring cooling water pipe (5) respectively, and ring cooling water pipe (5) run through spiral ring rib (8) along the combustor axis and set up, constitute first order water-cooling surface, combustion chamber (7) inside is provided with low U type tube bank (10) and high U type tube bank (9), and low U type tube bank (10) and high U type tube bank (9) are the criss-cross height and arrange, constitute second level water-cooling surface and third level water-cooling surface, and the whole spheroid cold flame combustion surface that forms, combustion chamber (7) are cylindric cladding outside U type tube bank.

2. The water-cooling type cold flame gas burner with the spiral ring ribs as claimed in claim 1, wherein the low U-shaped tube bundle (10) and the high U-shaped tube bundle (9) are both extended from the circularly arranged cooling water tubes (5), and the inlet and the outlet are connected with the semicircular water outlet header (4) and the semicircular water inlet header (2) to jointly form a water-cooling circulation structure of the device.

3. The water-cooling type cold flame gas burner of the spiral ring rib according to claim 1, characterized in that the ring cooling water pipes (5) are obliquely arranged on the spiral ring rib (8) at equal intervals along the circumferential direction, the inclination angle is the same as the structure inclination angle of the spiral ring rib (8), and the anti-backfire air inlet micro-channel (6) is formed by penetrating through the whole spiral ring rib.

4. The spiral ring rib water-cooling type cold flame gas burner according to claim 1, wherein the water inlet header (2) and the water outlet header (4) are of a semi-circular ring structure and are arranged above the air inlet chamber (11) in parallel, the ring cooling water pipes (5) comprise a ring cooling water pipe I (5a) and a ring cooling water pipe II (5b), and cooling water enters from the water inlet header (2) and flows through the ring cooling water pipe I (5a), the high U-shaped pipe bundle (9) and the low U-shaped pipe bundle (10) and then is collected in the water outlet header (4) through the ring cooling water pipe II (5b) arranged diagonally.

5. A spiral-ribbed water-cooled cold flame gas burner as claimed in claim 1, wherein said angle is arranged at 45 ° -75 °.

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