CN102878554B - Combustor special for coal water slurry combustion type cracking furnace - Google Patents

Abstract

The invention relates to burner technology and aims to provide a special burner for a coal-water slurry-fired cracking furnace. The main body of the burner has a hollow pre-combustion chamber; a coal-water slurry spray gun is installed on the top of the pre-combustion chamber, and a protective sleeve, a gas jacket, a primary air pipe and a gas air sleeve are sequentially set around the coal-water slurry spray gun. ; The secondary air pipe is connected to several secondary air outlets set on the top side of the pre-combustion chamber, and each secondary air outlet is evenly spaced on the wall of the pre-combustion chamber, and the distance between each secondary air outlet and the corresponding radial centerline The same rotation angle is formed between them; on the side of the top of the pre-combustion chamber, there is also an oil gun hole for inserting an oil gun. The present invention is applicable to three kinds of fuels: coal water slurry, light diesel oil, and methane hydrogen/natural gas; it mainly uses coal water slurry, which can replace methane hydrogen to produce products with higher added value; it can be quickly and conveniently switched during operation to meet According to the requirements of various working conditions, the automatic control system can save manpower and improve the economy and operability.

Description

Special burner for coal-water slurry cracking furnace

technical field

The invention relates to a burner, in particular to a special burner for a water-fired coal slurry cracking furnace.

Background technique

As a strategic resource, oil is also a non-renewable resource, which plays a major role in the country's economy and national defense security. With the development of industrialization, crude oil production in 2010 has exceeded 200 million tons, an increase of 6.9% over the previous year, the highest growth in recent years. The rapid development of the national economy has led to a great increase in the domestic demand for oil. Although my country is a major oil-producing country, most of my country's oil still relies on imports. In 2010, my country's crude oil imports reached 239 million tons, an increase of 17.5%. There are also many hidden dangers in China's oil industry caused by excessive oil imports. For example, the contradiction between oil supply and demand has led to excessive dependence on oil imports and rapid growth. The oil trade structure has not improved significantly. The trade method and import source are relatively single. Oil trade is affected by fluctuations in international oil prices. Large, oil foreign trade may lead to oil crises and other issues. Internationally, rising fluctuations in international oil prices will make countries all over the world compete for oil, and as oil is gradually consumed, this worldwide competition will become more intense.

Natural gas is a clean, convenient, safe and high-quality energy, and its main component is methane (CH ₄ ). If natural gas is used as fuel for cracking furnaces, it will inevitably lead to unreasonable utilization of energy. my country's natural gas resources are relatively scarce. With the acceleration of urbanization, the improvement of people's living standards and the enhancement of environmental protection awareness, the demand for natural gas is growing rapidly. It can be predicted that there will be a large gap in the domestic demand for natural gas in the future. . At present, the world's natural gas supply and demand are basically balanced, but the growth rate of demand is far greater than the growth rate of production. The development of China's natural gas is highly dependent on foreign countries. How to reduce the consumption of natural gas, increase the exploitation of natural gas, change the utilization mode and improve the utilization efficiency , this is a problem that needs to be solved.

Most of the ethylene cracking furnaces that have been put into production in China use natural gas as fuel. With energy conservation and emission reduction incorporated into the national energy development strategy and the price of natural gas rising, it is necessary to develop coal-water slurry gas replacement technology. Domestic research on coal-water slurry oil replacement technology has been very mature, and it has also been applied in industry. Coal water slurry is made by mixing water and coal in a certain proportion. The ignition and stable combustion of coal water slurry have special requirements on the burner. In order to meet the requirements of different operating conditions of the cracking furnace and in the case of problems in the combustion of coal-water slurry, the coal-water slurry cracking furnace needs to be able to operate with oil and gas to ensure the normal production of the cracking furnace. How to ensure the ignition and stable combustion of the coal-water slurry, and under different circumstances, the cracking furnace can operate with oil and gas to obtain the best working conditions, which is an urgent problem to be solved by the burner of the coal-water slurry cracking furnace.

Contents of the invention

The problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a special burner suitable for coal-water-slurry cracking furnaces. Stable operation of gas.

For solving technical problem, solution of the present invention is:

A special burner for a coal-water slurry cracking furnace is provided, including a coal-water slurry spray gun; the main body of the burner has horizontally extending edges and a raised center to form a hollow pre-combustion chamber; Coal slurry spray gun, and with the coal water slurry spray gun as the center, the protective sleeve, gas jacket, primary air pipe and gas air sleeve are sequentially set; the secondary air pipe is connected to several secondary Air outlets, each secondary air outlet is evenly spaced on the wall of the pre-combustion chamber, and the same rotation angle is formed between each secondary air outlet and the corresponding radial center line; on the side of the top of the pre-combustion chamber, there are also For inserting into the oil gun hole of the oil gun.

As an improvement, impeller swirlers are respectively arranged in the primary air pipe and the gas air sleeve.

As an improvement, there are two oil gun holes, namely a large oil gun hole and a small oil gun hole.

As an improvement, the hollow pre-chamber has a cylindrical shape; there are 10 secondary air outlets arranged on the top side thereof, and are arranged clockwise according to a preset angle.

As an improvement, a flame detector is provided on the top of the pre-chamber.

As an improvement, a fire viewing hole is provided on the top of the pre-combustion chamber.

As an improvement, a thermal insulation material layer is laid on the outside of the burner body.

The beneficial effects of the present invention are:

1. The traditional cracking furnace burner is only designed and operated for a single methane hydrogen fuel. This burner can be adapted to three fuels: coal water slurry, light diesel oil, and methane hydrogen/natural gas;

2. Traditional pyrolysis furnace burners use methane hydrogen as fuel, and the cost is high. This burner mainly uses coal water slurry, which can replace a large amount of methane hydrogen for the production of products with higher added value;

3. The three fuels used by this burner can be quickly and conveniently switched during operation to meet the requirements of various working conditions. Cooperating with the automatic control system can save manpower and provide more choices for the operation of the cracking furnace. Improve its economy and operability.

Description of drawings

Fig. 1 is a schematic sectional view of a special burner for a coal-water slurry cracking furnace;

Fig. 2 is a schematic bottom view of a special burner for a coal-water slurry cracking furnace.

Reference signs: 1 coal water slurry spray gun, 2 protective sleeve, 3 gas jacket, 4 primary air pipe, 5 gas air sleeve, 6 insulation material layer, 7 impeller cyclone, 8 pre-combustion chamber, 9 secondary Air duct, 10 secondary air outlet, 11 fire observation hole, 12 flame detector, 13 small oil gun hole, 14 large oil gun hole.

Detailed ways

Below in conjunction with accompanying drawing, embodiment of the present invention is set forth:

The main body of the special burner for the coal-water slurry type cracking furnace has horizontally extending edges and the center is convex, forming a hollow pre-combustion chamber 8; The slurry spray gun 1 is centered with a protective sleeve 2, a gas jacket 3, a primary air pipe 4 and a gas air sleeve 5 in sequence. The primary air pipe 4 and the gas air sleeve 5 are respectively provided with impeller swirlers 7 to ensure that the primary air and the gas air have a tangential velocity. The secondary air pipe 9 is connected to 10 secondary air outlets 10 provided on the top side of the pre-combustion chamber 8, and each secondary air outlet 10 is evenly spaced on the wall of the pre-combustion chamber 8, and the distance from the corresponding radial centerline Form the same rotation angle between them, so that they are arranged in a clockwise direction; on the side of the top of the pre-combustion chamber 8, there are also small oil gun holes 13 and large oil gun holes 14 for inserting oil guns. A fire viewing hole 11 and a flame detector 12 are also provided on the top of the pre-chamber. A thermal insulation material layer 6 is laid on the outside of the burner body. The flame detector 12 is used to detect the flame situation of the furnace, and can timely feed back to the control room to take relevant operations when the furnace burns to extinguish the fire. The large oil gun hole 14 is mainly used for inserting a high-energy igniter when igniting, and when the fuel oil working condition is used, the large oil gun is put into operation; the small oil gun 13 is mainly used for igniting by inserting a small oil gun when igniting. The main function of the pre-combustion chamber is to ensure sufficient mixing of fuel and air, and the secondary air fed into the pre-combustion chamber forms a swirling airflow in the furnace.

The invention can realize the cold furnace ignition of fuel oil and gas, and can realize the rapid switching of three kinds of fuels (oil, natural gas, coal-water slurry), so as to ensure the operation stability of the cracking furnace and expand the fuel range of the cracking furnace. High utilization value.

Way of working:

The invention can burn light diesel oil when igniting, and can burn coal-water slurry by heating the furnace to a certain temperature. When igniting, the high-energy igniter is inserted into the large oil gun hole 14, and then the light diesel oil of a certain flow is sprayed into the small oil gun hole 13. Remove the igniter immediately after the diesel is ignited, and then slowly increase the flow of fuel to heat the furnace to a stable temperature. When it is necessary to operate with fuel oil, a large oil gun can be used to meet the load requirements of the cracking furnace.

When the oil is injected and the combustion is stable and the temperature of the furnace rises to a certain level, the coal-water slurry operation can be carried out. Pure air with a certain temperature and a certain speed is used as the primary air, which enters the pre-combustion chamber 8 from the primary air outlet 4 through the impeller swirler 7, and mixes with the sprayed coal-water slurry atomized particles. Due to the axial and tangential velocity of the primary air entering the pre-combustion chamber 8, a strong swirling airflow is formed in the pre-chamber 8. Inside the swirling airflow, due to the effect of pressure difference, the high-temperature flue gas at the bottom has an upward direction. speed, a flue gas recirculation zone is formed in the pre-chamber 8. The atomized coal-water slurry particles sprayed from the coal-water slurry nozzle are mixed with the high-temperature flue gas, and the water contained in it evaporates rapidly, and the dry coal powder particles move with the returning high-temperature flue gas, and the pulverized coal gradually catches fire during the movement combustion. After the coal-water slurry has been stably burned, the oil gun can be withdrawn slowly.

Under different working conditions and when there are problems with oil and slurry feeding, the cracking furnace is required to be able to operate with gas. When the gas cold furnace is ignited, insert the high-energy igniter into the small oil gun hole 13, and slowly open the gas valve to prevent its deflagration. , the gas enters the gas jacket 3 from the gas air inlet, and is sprayed into the pre-combustion chamber 8 at a certain speed through the gas nozzle, mixes with the primary air and burns quickly, and withdraws from the high-energy igniter after the gas burns stably.

The advantage of the special burner for the coal-water slurry cracking furnace in the present invention is that the three fuels can be quickly and conveniently switched to meet the requirements of various working conditions. When the fuel oil working condition is switched to the coal-water slurry-fired working condition, the coal-water slurry can be injected to burn. Similarly, when cutting into the gas working condition, it can burn only by injecting gas, but at this time, the gas valve needs to be opened slowly to prevent deflagration. When the three fuels are switched, it is only necessary to ensure the stable operation of the previous working condition, inject the fuel that needs to be switched, and then withdraw the fuel of the previous working condition. This facilitates on-site operation, saves manpower, provides more choices for the operation of the cracking furnace, and improves its economy and operability.

Claims (1)

1. A special burner for a coal-water slurry type cracking furnace, including a coal-water slurry spray gun, is characterized in that the burner main body has a horizontally extended edge and the center is convex, forming a hollow pre-combustion chamber. The top of the chamber is equipped with a flame detector and a fire viewing hole; the pre-combustion chamber is cylindrical; there are 10 secondary air outlets arranged on the side of the top, and they are arranged in a clockwise direction according to a preset angle; Coal slurry spray gun, and with the coal water slurry spray gun as the center, a protective sleeve, a gas jacket, a primary air pipe and a gas air sleeve are sequentially set, and an impeller swirler is respectively installed in the primary air pipe and the gas air sleeve; The air pipe is connected to 10 secondary air outlets set on the top side of the pre-combustion chamber, and each secondary air outlet is evenly spaced on the wall of the pre-combustion chamber, and the same rotating clamp is formed between each secondary air outlet and the corresponding radial centerline Angle; on the side of the top of the pre-combustion chamber, there is also an oil gun hole for inserting an oil gun. There are two oil gun holes, namely a large oil gun hole and a small oil gun hole; layer of insulation material.