At present, with the advancement of domestic urbanization central heating, the design and manufacture of industrial chain grate boilers have developed in a large scale, which directly affects the horizontal uniform air supply of industrial chain grate combustion conditions, and is an important historical focus of energy-saving combustion research topic. Especially in recent years, a large number of beam grate with equal amount of air supply mode has been produced, which is equipped with the social operation of large chain grate boiler. Due to many fatal combustion defects, the market problems of boiler transformation in the later stage are formed. Due to the successful application of the patented technology of equal pressure air supply invention, the traditional monopoly market design and manufacturing pattern has been broken. While promoting the progress of boiler combustion technology, there has been a phenomenon of fish-eye mixing. The patented technology of equal-pressure air supply is based on the principle of aerodynamics, not a simple superposition of digital technology and simple technical imitation.

Dalian Wafangdian Yongning Grate Manufacturing Co., Ltd. is an earlier grate manufacturing enterprise in China that invented and applied the patented isobaric air supply technology and related technology patents for chain grate boilers. It is a grate manufacturing enterprise with isobaric air supply technology that is rarely owned by the industrial boiler industry, with patent number:( 200620149018. 9) (200710000532.5) (200810110545.52).

Since 2005, Dalian Wafangdian Yongning Grate Manufacturing Co., Ltd. has produced more than 5400 40-160 tons of chain grates. Supporting industrial chain grate boiler manufacturing enterprises, with large chain grate isobaric air supply aerodynamics test bench and laboratory, are large chain grate manufacturing enterprises that master large chain grate isobaric air supply aerodynamics calculation and large chain grate mechanical calculation, 100 to ensure the operation safety of large chain grate boiler customers.

1. Basic conditions for equal pressure air supply

The design and operation of large industrial chain grate boiler is different from the combustion cross-sectional width of small industrial chain grate boiler, especially for central heating industrial chain grate boiler, grate cross-sectional width of 9.6-15M, which effectively solves the problem of horizontal combustion and vertical combustion of central heating boiler. High-efficiency and energy-saving combustion conditions, resulting in random changes in air volume, wind pressure and other parameters, are facing the gradual implementation of automated centralized control reality. (For example, 84MW of Hongda Thermal Power Co., Ltd., Gongzhuling City, Jilin Province, 91MW and 112MW of beam chain grate in Xinjiang). To solve the problem of uniform air supply which directly affects the dynamic combustion conditions, the core problem is how to realize the equal pressure air supply and automatic adjustment compensation of the air chamber. According to the principle of aerodynamics, equal pressure air supply is realized, and the design of air chamber should conform to the laws of aerodynamics, static pressure balance and dynamic pressure change. In the mathematical model based on the aerodynamic calculations. It is not a simple ideal digital technology superposition under static conditions, but pays more attention to the calculation of data. Without a perfect independent air chamber, there is no way to achieve the longitudinal combustion problem of industrial chain grate boilers that meet the requirements of (GB/T3271-2002 technical conditions for chain grate). The perfect independent air chamber is equipped with equal pressure air supply that should conform to the aerodynamic principle; and the application of automatic adjustment compensation measures.

2. Lateral combustion and system combustion engineering problems
For industrial chain grate boilers used for central heating, the cross-sectional width of the grate is 9.6-15M. How to effectively solve the problem of horizontal combustion of the boiler, due to the continuous widening of the cross-sectional width of the grate, which is different from that of small chain grate <5m, the use of two-way side air supply, any equivalent modified air supply, or the air supply mode of large air warehouse and small air bucket imported Danish technology will not have great impact on combustion, the grate cross-sectional width of 9.6-15M, more attention is paid to how to effectively solve the problem of boiler horizontal combustion.

A, the so-called system combustion engineering problem refers to, coal bunker coal distribution can achieve horizontal coal distribution, to prevent coal bunker coal distribution, the emergence of pagoda type. (Large patches set on both sides, powder in the middle.) Whether it is possible to achieve uniform coal bunker coal seam particles and horizontal coal distribution. Whether it can be realized, the primary problem of energy-saving and high-efficiency combustion under the ideal state is very important for large-scale industrial chain grate boilers to solve the historical difficult problems of horizontal combustion.

B, large chain grate boiler, there is a system combustion engineering problems. Coal bunker coal distribution to achieve horizontal distribution of coal, connecting coal bunker and layered coal hopper between the design of the coal drop pipe, for layered coal hopper can achieve uniform coal supply; for large industrial chain grate boiler to solve the problem of horizontal combustion of an important factor.

C, large chain grate boiler, system combustion engineering problems. The cross-sectional width of the grate is 9.6-15M, which effectively solves the problem of horizontal combustion of the boiler, and whether the grate grate cross-section can be leveled, uniform coal seam, particle size and uniform thickness can be used to ensure reasonable combustion conditions. For large industrial chain grate boilers, it is an important factor to solve the problem of horizontal combustion.

In large chain grate, the problem of application defects of stratified coal feeding device is the most prominent problem in reality. At present, most manufacturers, using imitation or simple size enlargement application, have no ability to carry out accurate mechanical calculation of stratified coal feeding device, which is a common phenomenon in society without product mechanical calculation book. It is most obvious in the application of stratified coal feeding device above 70MW. For large chain grate with grate cross-sectional width of 9.6-15M, there is no basic use measure to ensure the thickness of coal seam. The focus of attention is: product design mechanics calculation sheet, basic use effective measures to ensure the thickness of coal seam. It is very important for large industrial chain grate boilers to solve the historical difficult problems of horizontal combustion, and the design guarantee measures for safe operation.

D. uniformity of horizontal air distribution of chain grate directly affecting combustion conditions

(1) Influence on the loss of incomplete combustion of combustible gas q3:

Due to the serious lack of oxygen in the weak wind area with small ventilation volume, the thickness of the reduction layer in the coal seam will increase, and a considerable part of the air flow will react with carbon during the ascent of the coal seam. The reduction process is an endothermic reaction, so the surface temperature of the coal seam will drop; this will unnecessarily increase the burden on the furnace, resulting in the rise of q3.

⑵ Influence on mechanical incomplete combustion q4:

the horizontal air distribution of the grate is uneven, which will delay each combustion stage in the coal seam in the weak wind area. a considerable part of the carbon will fall into the ash before it is burned out, and the average carbon content of the ash will obviously increase, thus increasing the q4 loss.

(3) Impact on smoke exhaust loss q2:

Due to the uneven horizontal air distribution in the grate, in the area of high wind pressure, the combustion process is relatively rapid, prone to fire, so that a large number of cold air without reduction and chemical reaction directly into the furnace, not only reduce the furnace temperature, affect the combustion, while the exhaust temperature rise q2 exhaust smoke loss increases.

The focus of isobaric air supply and energy-saving combustion is to solve the problem of horizontal combustion, including a line of ignition under ideal combustion conditions. The independent air chamber is a line to solve the longitudinal combustion problem, including the burn-out under the ideal combustion condition. It is the basic condition for determining the efficiency of boiler combustion operation.

1. Design principle of isobaric air chamber:
The air flows out from the side hole of the air duct. When the air passes through the side hole, it is subjected to the static pressure perpendicular to the wall surface of the air duct and the dynamic pressure parallel to the axis direction of the air duct. Under the action of the static pressure P1, the air flows out through the side hole and generates a static pressure velocity perpendicular to the wall surface of the air duct. Under the action of dynamic pressure, the airflow velocity in the air duct is parallel to the axis of the air duct. The actual velocity of air is the composite velocity of static pressure and dynamic pressure.
The actual velocity of the air is related to the total pressure of the section where the side hole is located, while the outflow direction of the airflow in the side hole is related to the ratio of static pressure to dynamic pressure. Obviously, the greater the static pressure and the smaller the dynamic pressure, the greater the outflow angle. This indicates that the airflow direction is closer to the vertical of the air duct wall image. (Air flow angle: the angle between the actual speed of the air and the axis of the air duct becomes the outflow angle, which is tangent.)

2. Conditions for realizing equal pressure air supply

Soviet scholar B.B. Batulin's experiments confirmed that for equal cross-sectional air duct with equal cross-sectional area, the airflow at the side hole at the head of the air duct is almost parallel to the axis of the air duct, and then gradually changes direction. When approaching the terminal side hole, the airflow is almost perpendicular to the axis. At the same time, the static pressure and air supply are gradually increased toward the end. For example, the air supply volume of the side hole at the head end of the air duct and the air supply volume of the side hole at the terminal end are 20 times of the former, which is impossible to achieve uniform air supply.

In order to achieve uniform air supply, the static pressure of each side hole must be kept constant over the entire length of the air duct. The flow coefficient or local resistance coefficient of each side hole is equal. It is also necessary to make the direction of the air flow sent out perpendicular to the axis of the air duct as much as possible, that is, the outlet angle of the air flow may be larger. In order to keep the static pressure on the full length of the air duct unchanged, the speed at the head end of the air duct must be greater than the speed at the end, and the dynamic pressure difference between the head end and the end (or the dynamic pressure difference between the holes on both sides) is equal to the pressure loss on the full length of the air duct.
At the same time, it is also necessary to change the cross-section along the length of the air duct; that is, the cross-section of the air duct should be gradually reduced toward the end. The static pressure generated by the decrease of flow velocity is often greater than the pressure loss of the air duct, so the section has to be reduced along the forward direction of the air flow, so that the rich static pressure is converted into dynamic pressure. Only in this way can the static pressure on the whole length of the air duct remain constant.
3. The difference between equal pressure air supply and equal amount air supply

■ Definition of isobaric air supply: static pressure balance and dynamic pressure change.

■ The air duct with equal pressure air supply, whether round, square or rectangular, changes along the air supply direction and the air supply axial section of the air duct, and the air outlet area of the side holes and slits is unchanged. Therefore, the air outlet speed is the same. If the flow angle of the first side hole is greater than 60 degrees, a better uniform air supply effect can be obtained.

■ Structural design of isobaric air supply: the isobaric air supply duct and the standby air chamber are adopted to ensure automatic adjustment under random conditions of combustion conditions of the chain grate boiler; The static pressure on the whole length of the air duct remains constant, which is the basic guarantee basis for realizing isobaric air supply and conforms to the theoretical basis of nonlinear mathematical model control for aerodynamic calculation. It is the fundamental difference between the equal pressure supply air chain grate and the equal supply air chain grate; it is also the fundamental difference between the intellectual property rights of the national chain grate and the imported technology and grafting technology from abroad, and is not limited by the large-scale development of the width and size of the chain grate.

■ Facing the large-scale development of large-scale chain grate boilers, single chain grate is equipped with large-scale industrial chain grate boilers, which requires a perfect combination of advanced technology and design and manufacturing strength to ensure the safe operation and high-efficiency and energy-saving operation of large-scale chain grate boilers, conforms to the national environmental protection and energy-saving industrial policy, and is not a simple combination of numbers.

■ Definition of equal air supply: full-length static pressure change and dynamic pressure change.

■ Equal air supply is a misunderstanding that has not come out of the boiler industry for many years. The famous chain grate boiler expert, Professor Zhang Yuanzhong of Shanghai Institute of Machinery, has conducted decades of research for this purpose, which also provides valuable experience for our research today. In the application of industrial chain boilers, such as: adjusting the wind deflector of the air inlet of the air duct, changing the cross section of the air outlet of the air duct, and introducing the air supply form of the small air bucket in the wind chamber with Danish technology, etc., in the small chain grate, the reflection is not obvious due to the small cross-sectional size of the grate. It has a certain effect in practical application, but it has not been applied to the large chain grate, and the key can not adapt to the dynamic random change of air volume to wind pressure. The application of any form of equal supply air in industrial chain boilers has proved to be fatal in the application of large chain grate and combustion operation.

■ The characteristic of equivalent air supply is that this type of air supply duct is of equal cross-section. Since the static pressure increases gradually along the air supply direction and the air duct axis direction, the area of the side hole section or slit must be changed and gradually decrease along the air supply direction and the air duct axis direction. At this time, the outlet velocity of the side hole or slit is different. Strictly speaking, this type of air supply duct can only carry out equal air supply. There is no guarantee that the outlet wind speed is equal.

■ Another form of equal air supply is in the state that the air supply duct is of equal cross-section, and the wind deflector with different cross-sections hopes to achieve equal air supply.

Due to the constant random changes of static pressure and dynamic pressure in the air supply, the outlet velocity of the side hole and slit airflow is not the same, and the same can not guarantee that the outlet wind speed is equal. The air supply form of the small air bucket in the imported Danish technology wind chamber is the equal air supply mode applied to the small chain grate in Denmark. In the static state, the ideal wind chamber is an equal pressure air chamber. Since the small air hoppers in the arrangement are of equal cross section, the static pressure and dynamic pressure of the wind chamber fluctuate little for the different outlet speeds of the small chain grate. Data inquiry confirms that Denmark is only used for boilers below 40 t/h, can the same amount of air supply for small coal hopper in the wind chamber be applied to large chain grate boilers? Shanghai Sifang is preparing to introduce 160 t/h ton angle tube boilers in the third phase. The problem of uniform air supply, which directly affects combustion, has not been solved, which is the reason why it has not been implemented.

However, for large-scale industrial chain grate boilers used for central heating, the cross-sectional width of the grate is 9.6-15M, and any equivalent air supply form cannot adapt to the appropriate uniform air supply operation conditions required by large chain grate and randomly changing combustion conditions. It does not meet the basic conditions of aerodynamics, equal pressure air supply. Can not effectively solve the boiler horizontal combustion problem. Due to the limitation of the structural design conditions of the wind chamber, only a simple technical patchwork can be carried out at present. The important basic condition of equal air supply in the original design gale chamber is lost; the dynamic outlet wind speed cannot be guaranteed to be equal. Therefore, no designers at home and abroad have carried out serious aerodynamic calculations and actual aerodynamic wind tunnel tests. To be precise, there is no detailed design aerodynamic calculation and mechanical calculation to confirm the reliability and safety of its application.

4. Centralized control of combustion automation for large beam type chain grate boilers used for central heating is an inevitable trend of development. Random changes in combustion conditions during boiler combustion, especially the strengthening of environmental protection law enforcement, the application of nitrogen removal in the furnace and secondary air, and the control of excess air in the main combustion chamber; The control requirements for equal pressure uniform air supply are more stringent. The automatic compensation and independent adjustment of the horizontal independent air chamber of the main combustion chamber are more important for the equal pressure air supply with the cross-sectional width of the grate 9.6-15M. In relation to the ideal energy-saving and efficient combustion conditions, it is an important core technology for the technical adjustment of one line of ignition and one line of burnout. The same amount of air supply, the wind chamber small air bucket air supply mode can not be realized, the boiler combustion process of random changes in combustion conditions, horizontal combustion independent air chamber automatic compensation and independent adjustment problems.

For large cross-beam chain grate used for central heating, (grate cross-sectional width 9.6-15M) different equal pressure air supply design and structural arrangement are adopted according to combustion conditions.

1. According to the randomly changing working conditions of boiler combustion, the first, second, fifth, sixth, seventh and eighth air chambers in the longitudinal direction adopt the equal pressure air supply design with air supply on both sides and automatic pressure regulation of the horizontal inclined plate. Both ends are provided with air duct and air chamber digital display air pressure gauge.

According to the randomly changing working conditions of boiler combustion, the 3rd and 4th air chambers of the longitudinal main combustion chamber adopt horizontal air supply on both sides and partition in the middle. Horizontal variable cross-section equal pressure air duct, equal cross-section, adjustable side air outlet, horizontal 6-section independent air chamber, automatic pressure regulating air chamber equal pressure air supply design. Six groups of independently adjustable air distribution devices are installed on the side air outlets of the 6 horizontal independent air chambers and the automatic pressure regulating air chambers, which independently adjust and compensate the combustion and light-off synchronous working conditions caused by uneven lateral thickness and particle size of the coal seam. Application of technical effect is obvious! Both ends are provided with air duct and air chamber digital display air pressure gauge.

2. The uneven coefficient of horizontal air distribution is based on the technical conditions of chain grate A.4.3 The uneven coefficient of horizontal air distribution of grate: the third air chamber is taken as the measuring air chamber, the measuring method is 200mm horizontally along the grate row as one side point, and the uneven coefficient of three columns of measuring point calculators is arranged. Measured and calculated with a pitot tube, micro-manometer, di-tube or hot-ball anemometer. Calculation method GB/T3271-2002.

1 chain grate longitudinal combustion problem:

⑴ In the preheating and drying section, the fuel travels slowly along the grate after falling from the coal hopper or stratified coal feeder, and is heated by the conduction of the furnace flue gas and the front arch, and the water gradually evaporates. However, the thermal conductivity of coal is very poor, and the heat transfer is very slow, which is about 0.2-0.5 m/h, which is only about 1/10 of the speed of the grate.

⑵ The initial volatile matter of coal is separated out and burned in the section. The coal seam moves backward with the grate. The heat transfer is carried out from top to bottom. The dividing line of each section is inclined backward. The main factors affecting the inclination degree are the grate speed and heat transfer speed.

⑶ Coke combustion section, the coal seam in this section burns violently, and the furnace temperature is above 1200 ℃. It is the main section of chain grate combustion, which is divided into oxide layer and reduction layer along the height (because the height of oxide layer is much lower than the thickness of coal seam).

In the burnout area, the coal seam forms ash and slag. It is worth noting that the problem is that the tail slag layer is sandwiched with carbon. Due to the high heating temperature above the coal seam, the lower fuel air is fully and quickly forming ash. The intermediate unburned coke is entrained by the upper and lower ash layers, which is an increase in mechanical incomplete combustion loss. It is important to reduce the loss of the (3)/(4) segment q4. The reason is that the air volume in the front and rear sections is too large, and the main combustion area is severely anoxic.

2. Based on aerodynamics and mathematical model, equal pressure air supply and independent air chamber. For large cross-beam chain grate used for central heating, (grate cross-sectional width 9.6-15M) different equal pressure air supply design and structural arrangement are adopted according to combustion conditions.
Longitudinal air chambers 1, 2, 5, 6, 7 and 8 adopt equal pressure air supply design with air supply on both sides and automatic pressure regulation of inclined plate. Both ends are provided with air duct and air chamber digital display air pressure gauge.

The 3rd and 4th air chambers of the longitudinal main combustion chamber adopt air supply on both sides and partition in the middle. Variable cross-section equal pressure air duct, equal cross-section, adjustable side air outlet, horizontal 6-section independent air chamber, automatic pressure regulating air chamber equal pressure air supply design. Six groups of independently adjustable air distribution devices are installed on the side air outlets of the 6 horizontal independent air chambers and the automatic pressure regulating air chambers, which independently adjust and compensate the combustion and light-off synchronous working conditions caused by uneven lateral thickness and particle size of the coal seam.

3. Longitudinal combustion and grate test

At present, more than 70MW of beam grate, longitudinal combustion, configuration of more than 8 independent equal pressure air chamber. Use air supply on both sides. Visual control system for longitudinal combustion of air volume of air blower and electric actuator equipped with independent air volume measurement and control. Vertical combustion, burnout line synchronous conditions of random changes in the central control. Effective control of boiler combustion efficiency, boiler output and slag carbon content, energy-saving and efficient combustion technology parameters.

The problem of equal air supply affecting longitudinal combustion is not a simple distribution and superposition of air chamber arrangement numbers. Especially in recent years due to monopoly production, and publicity, resulting in a large number of equal amount of air supply mode, beam grate with large chain grate boiler social operation. Due to many fatal boiler combustion defects, the market problems of boiler transformation in the later period have been formed. Congenital design fatal defects in the transformation process is unable to change the application of reality. It does not meet the current requirements of energy conservation and emission reduction and technological development.

According to the technical condition A2.1 of chain grate, the total air flow is measured and calculated by pitot tube, micro manometer, di tube or hot ball anemometer in the blower section of the boiler. Calculation method GB/T3271-2002

(1) Test of wind pressure in air chamber according to technical condition A2.4 of chain grate: The test method uses a special bell-type pressure measuring seat and micromanometer to measure on the grate surface, and the test tool uses Pitot tube, micromanometer, Dy tube or hot ball anemometer to measure and calculate. Calculation method GB/T3271-2002

(2) According to the technical conditions of chain grate A.4.1 Test of average wind pressure in the air chamber: the test method is divided into two to three groups along the cross section of the grate on the coal-free grate. The wind pressure of the downwind chamber of the grate is measured directly by the hot ball anemometer. Two measuring points are arranged on each grate to test the average wind pressure in the front and rear air chambers. Calculation method GB/T3271-2002.

(3) Test of average wind pressure in air chamber according to technical condition A.4.2 of chain grate: the average wind pressure in air chamber is the average of all measured wind pressures in air chamber. Taking the third air chamber as the measuring air chamber, the measuring method: on the coal-free grate, the grate surface is divided into two to three groups. The wind pressure and wind speed of the downwind chamber of the grate directly measured by the hot ball anemometer. The horizontal of the beam grate and the two measuring points between the longitudinal beams are linearly distributed, and the average wind pressure of the wind chamber is tested and the test value is calculated. Calculation method GB/T3271-2002.

(4) Wind retention rate of the wind chamber: defined as an index to measure the air tightness performance of the main wind chamber. The measurement method is based on the third air chamber, when the third air chamber is fully opened and the other air chambers are fully closed. The blow-by rate of the air flow of the blow-by wind from the third wind chamber to the second wind chamber and the fourth wind chamber is measured. The calculation result is the wind retention rate of the third wind chamber. Calculation method GB/T3271-2002

(5) Air chamber blow-by rate: defined as an indicator of the air tightness performance of the main air chamber to other air chambers. The measurement method is based on the third and fourth air chambers. When the third air chamber is fully opened and the other air chambers are fully closed. Measure the wind pressure and air volume on the grate surface. Cover the corresponding coal seam, measure the ratio of the air volume of the second air chamber and the fourth air chamber to the total air volume of the third air chamber. Calculation method GB/T3271-2002

The measurement method is based on the third and fourth air chambers, and the percentage of the ratio of the air volume when the third air chamber is fully closed to the total air volume of each air chamber of the entire grate is the air blow-by rate of the air chamber. Measuring tools hot ball wind speed, wind pressure meter. Calculation method GB/T3271-2002.

According to the technical condition of chain grate A.4.5, the flow rate when the air door is fully closed is defined as: the air flow when the air door is fully closed and the air flow when the air door is fully opened. Test conditions The grate damper adopts a positioning push-pull damper, and the closing damper plate is glued with foamed silica gel strips to ensure good sealing performance during closing. Measuring tools hot ball wind speed, wind pressure meter. Calculation method GB/T3271-2002.

1. The independent air chamber design of equal pressure air supply is based on the combustion conditions, the automatic adjustment of boiler random combustion change parameters based on aerodynamic and mathematical models, and the independent air chamber design. Adopt air supply on both sides and middle partition. The isobaric air chamber design of the horizontal variable cross-section measuring air outlet on both sides, the horizontal six independent and automatic adjustment of the independent air chamber, the measuring air outlet is equipped with an independent adjustment of the air door mechanism, to achieve the basic conditions of equal pressure air supply in line with the combustion conditions, is currently applied in the 84MW beam grate project. Boiler test data shows that the ideal combustion design requirements of the boiler are met or exceeded.

The independent air chamber design of equal pressure air supply is based on the combustion conditions, the boiler random combustion change parameters are automatically adjusted on the basis of aerodynamic and mathematical models, and the independent air chamber design is designed. Adopt air supply on both sides and middle partition. The isobaric air chamber design of the horizontal variable cross-section measuring air outlet on both sides, the horizontal 6 independent air chambers with independent automatic adjustment, the side air outlet is equipped with an independent adjustable air door mechanism, the boiler operation and combustion are dynamic and constantly changing combustion conditions, and the isobaric air supply meets the design requirements of combustion conditions.

2. Large chain grate boilers, especially the beam grate with a cross-sectional width of 9.6-15M and longitudinal combustion, are equipped with more than 8 independent equal-pressure air chambers, which affect the equal amount of air supply for longitudinal combustion, and are not simple air chamber arrangement digital distribution and superposition. Visual control system for longitudinal combustion of air volume of air blower and electric actuator equipped with independent air volume measurement and control. Effective control of boiler combustion operation efficiency, boiler output and slag carbon content, energy-saving and high-efficiency combustion technical parameters, to achieve the adjustment of synchronous ignition line, linear burnout line of energy-saving and high-efficiency combustion, easy to boiler operation automation control.

3. The combustion ignition line and burnout line under ideal combustion conditions should be straight lines, which is a problem that cannot be solved by all large beam chain grates with equal air supply mode at present. The S-shaped linear combustion conditions within the range of 200mm of the ignition line confirm that there are still needs to be improved in the boiler combustion system engineering, and the design is insufficient.
Large chain grate boiler, system combustion engineering problems. The cross-sectional width of the grate is 9.6-15M, which effectively solves the problem of horizontal combustion of the boiler. The first problem faced is how to ensure the horizontal and uniform distribution of coal and coal falling in the coal bunker. Combined coal distribution speed> 10-15M/min, uniform coal distribution speed. It is currently a subject in the process of domestic research. (Our company has successfully studied and is waiting for engineering application) The coal distribution defect of the pagoda type coal bunker is the primary problem affecting combustion.

4, large chain grate boiler, system combustion engineering problems. The cross-sectional width of the grate is 9.6-15M, which effectively solves the problem of horizontal combustion of the boiler and the design defects of the stratified coal feeding device in the design application. (Most domestic manufacturers use imitation or simple technology to scale up. Few people can carry out layered design mechanics calculations with real and serious attention, let alone product mechanics calculations.) In addition to the factors affecting the safe operation of large chain grate boilers, the common problems at present are: due to the structural design of the layered feed device, the application of more than 70MW central heating industrial boilers, the deformation of the coal roller, the thermal deformation of the coal gate, which directly affects the uneven thickness of the transverse section of the burning grate and the combustion conditions of the boiler. The independent air chamber with equal pressure air supply technology has an adjustable device according to the combustion condition.

Small industrial chain grate boiler with what kind of improved equal amount of air supply combustion air supply mode, the boiler combustion conditions are not obvious, different from large-scale central heating industrial chain grate boiler. No matter what kind of equal air supply mode is adopted, it can not meet the changing boiler combustion conditions. Practical application confirms that the combustion conditions of industrial chain grate boilers, with the needs of modern central control, constantly change the boiler air, blast, parameter changes and grate feed speed, to achieve reasonable energy-saving combustion. The uniform air supply of the boiler under ideal static conditions is difficult to adapt to the changing combustion operating conditions. The large chain grate independent air chamber designed with the patented technology of equal pressure air supply can meet the equal pressure uniform air supply under the changing dynamic combustion conditions of the large central heating industrial chain grate boiler, realize the ideal combustion condition of the industrial chain grate boiler, and achieve the purpose of energy-saving combustion.