CN2373685Y - Inertial gradation vortex coal powder burner - Google Patents

Abstract

The utility model relates to an inertial thick-lean swirling pulverized coal burner. The main feature of the burner is that a pulverized coal concentrator is installed at a certain distance from the primary air channel of the existing burner to the nozzle of the burner. The primary air powder is in the form of direct current. After passing through the concentrator, the distribution of pulverized coal concentration from the center side of the burner to the side close to the secondary air is formed in the primary air channel, and the concentration of the concentrator is a certain distance from the nozzle of the burner to keep the distribution trend of the primary air powder. Spray into the furnace. The utility model simultaneously solves the problems of high efficiency of pulverized coal combustion, stable combustion, low NOx discharge, prevention of slagging and prevention of high-temperature corrosion.

Description

An inertial thick-lean swirling pulverized coal burner

The utility model relates to an inertial density swirling pulverized coal burner.

my country is one of the few countries in the world where coal is the main source of energy. The coal used in the power industry is characterized by variable coal types and poor coal quality. In the combustion technology of pulverized coal boilers, the basic requirements for pulverized coal combustion are: high efficiency, stable combustion, low pollution, prevention of slagging and prevention of high temperature corrosion. In order to save energy, it is necessary to ensure high-efficiency combustion; due to the poor coal quality and variable coal types used in power plants in my country, the problem of stable combustion is prominent, especially when operating at low loads, oil is often used to support combustion, which increases the cost of power generation ; With the improvement of people's living standards, the requirements for environmental pollution control are getting higher and higher, and the requirements for low pollution in pulverized coal combustion are becoming stronger and stronger; slagging in the burner area and high-temperature corrosion of water-cooled wall tubes seriously threaten the boiler safe, economical and stable operation. Although some pulverized coal combustion devices in my country can achieve variable load and low NOx combustion, the primary air elbow bifurcated separator is located outside the burner, and the dense-phase primary air enters the furnace through the dense-phase burner, while the dilute-phase primary air passes through the dilute phase. The phase primary tuyere enters the furnace, and the structure is complex; because the dilute-phase primary air (accounting for 45-65% of the primary air volume) in the primary air does not enter the dense-phase burner, the excess air coefficient of the air supplied by the dense-phase burner is less than 1, thus Affect the combustion efficiency of pulverized coal, and easily cause slagging and high temperature corrosion in the dense phase burner area.

The purpose of this utility model is to propose an inertial thick-lean swirl pulverized coal burner which is simple in structure and can realize high efficiency, stable combustion, low pollution, slagging prevention and high temperature corrosion prevention of pulverized coal combustion at the same time. .

The purpose of this utility model is achieved in this way. The utility model consists of a furnace 1, a burner 2, a concentrator 3, a cyclone 4, a direct current secondary air passage 5, an annular partition 6, a swirl secondary air duct 7, Burner primary air passage 8, central pipe 9, primary air powder delivery pipe 10, damper baffle 11, secondary air duct 12, damper baffle 13, the main points of the invention are: in the primary air passage of the burner, the combustion Install a pulverized coal concentrator at a certain distance from the nozzle. After the pulverized coal air sent from the primary air powder conveying pipeline flows into the primary air duct 8 of the burner, it passes through the concentrator 3 installed in the primary air duct 8 of the burner in the form of direct current, and then changes from the original uniform distribution of pulverized coal concentration to The concentration of pulverized coal is distributed from high to low from the side of the center of the burner to the side close to the secondary air. Since the concentrator 3 is a certain distance from the furnace 1, and the primary air is direct current, the pulverized coal concentration is higher than that of the pulverized coal. The diffusion from the high side to the lower side is slower, so that the primary air powder maintains such a distribution trend of coal powder concentration from high to low from the center of the burner to the outside. The burner 2 is sprayed into the furnace 1, and the secondary After the wind enters the burner through the secondary air duct 12, it is divided into two parts: swirling flow and direct flow. They enter the furnace 1 through the swirling secondary air duct 7 and the direct current secondary air passage 5 respectively, and the opening of the damper baffles 11 and 13 is adjusted. The ratio of swirling secondary air and direct current secondary air can be changed. The pulverized coal flow near the center of the burner has a high concentration of pulverized coal, and enters the high-temperature recirculation zone, forming a high-temperature, high-concentration zone, which is conducive to the ignition of pulverized coal and flame stability. Since the pulverized coal air flow forms a density distribution, and the secondary air is also divided into swirl and direct flow, the fuel deviation combustion and secondary air staged combustion can effectively inhibit the formation of NOx and reduce NOx emissions. After the pulverized coal airflow with higher pulverized coal concentration on the inside is on fire, the pulverized coal airflow with lower pulverized coal concentration outside and the secondary air are mixed in time to ensure the oxygen required for combustion, which conforms to the principle of air supply with combustion, and the primary air The primary air rate of the powder remains unchanged, which ensures efficient combustion. The primary air powder of the new burner is direct flow, and the coal powder is concentrated to the center of the burner, thus forming a strong oxidizing atmosphere near the water wall in the burner area, and the melting point of ash is higher in the oxidizing atmosphere, thus preventing slagging , to prevent the formation of high temperature corrosion.

The utility model simultaneously solves the problems of high efficiency, stable combustion, low NOx emission, slagging prevention and high temperature corrosion prevention of pulverized coal combustion, which has a very positive effect on the efficient and low-pollution utilization of my country's unique low-quality coal.

Fig. 1 is a schematic structure diagram of the utility model

Embodiment: The structure of the concentrator in the utility model can be varied, such as adopting one or several conical blades to form a louver type pulverized coal concentrator. The collision produces gas-solid separation, thus forming a distribution of pulverized coal concentration from high to low from the side of the burner center to the side close to the secondary air.

Claims (1)

1. A kind of inertia thick-lean swirling pulverized coal burner is characterized in that: a pulverized coal concentrator is installed at a certain distance from the burner nozzle in the primary air channel of the burner.