Vertical powder boiler system and method of use thereof

Abstract

The present invention relates to a vertical powdered fuel boiler system and a method for using the same. In order to solve the problems of unstable combustion and unstable furnace pressure in the existing vertical pulverized coal boiler with a bottom-mounted burner, the vertical powdered fuel boiler system includes a furnace, a powdered fuel circulating combustible gas generator, etc. The powdered fuel circulating combustible gas generator is arranged on one side of the vertical combustible powdered fuel boiler, a dust collecting heat exchange chamber is arranged at the bottom of the furnace, an air distribution device is arranged between the dust collecting heat exchange chamber and the furnace, and a plurality of ash collecting funnels are arranged at the bottom of the dust collecting heat exchange chamber, which are evenly distributed around the vertical center line of the dust collecting heat exchange chamber. Each ash collecting funnel is in the shape of an inverted cone tube with a larger top and a smaller bottom. A vertical ash discharge pipe is connected to the lower end of each ash collecting funnel, and an ash discharge valve is arranged on each vertical ash discharge pipe. The vertical powdered fuel boiler system and the method for using the same of the present invention have reliable operation and sufficient combustion, and are suitable for serving as various industrial and domestic boilers such as power plant boilers and centralized heating boilers.

Description

Technical Field

[0001] The invention relates to a vertical powdered material boiler system and a use method thereof. Background Art

[0002] The Chinese invention patent with the publication number CN 104791775 B and the authorization announcement on March 23, 2018 discloses a vertical pulverized coal boiler with a bottom-mounted burner, and the Chinese utility model with the publication number CN 204554755 U and the authorization announcement on August 12, 2015 discloses a waste heat boiler used in conjunction with it.

[0003] The pulverized coal preheating burner disclosed in CN 104791775 B comprises a preheating combustion chamber, a gas-solid separator and a returner connected in sequence, which form a circulating fluidized bed type coal gas generating device. The vertical pulverized coal boiler has the advantages of sufficient combustion, small tail gas treatment burden, low cost, simplicity and convenience, and safe and environmentally friendly flue gas emission.

[0004] However, during use, unstable combustion and unstable pressure in the furnace or preheating combustion chamber may sometimes occur. Once unstable combustion and unstable furnace pressure occur, it is difficult to readjust to a balanced state. It is often necessary to stop the furnace, purge it multiple times, add sand again, feed materials and ignite it, which is very inconvenient. Summary of the invention

[0005] The technical problem to be solved by the present invention is how to overcome the above-mentioned defects of the prior art and provide a new type of vertical powdered coal gas boiler system with stable combustion and stable furnace pressure and a method of using the same.

[0006] In order to solve the above technical problems, the vertical powder boiler system includes a furnace, a powder circulating combustible gas, a powder circulating combustible gas generator, a powder feeding fan, a primary fan, a secondary fan and a flue, wherein the furnace is cylindrical, the powder circulating combustible gas generator includes a preheating combustion chamber, a cyclone gas-solid separator and a returner, the three of which are connected in series to form a circulating fluidized bed type gas generating device, a fuel powder feeding pipe and a sand adding pipe are provided on the lower side wall of the preheating combustion chamber, wherein the fuel powder feeding pipe is connected to the outlet of the powder feeding fan, and a feeding pipe is also provided on the fuel powder feeding pipe, which is connected to the discharge port at the bottom of the powder bunker through a screw feeder or a rotary valve, a sand adding hopper is provided on the top of the sand adding pipe, and a sand adding valve is provided, the characteristics are:

[0007] The furnace is provided with a pressure sensor or a pressure gauge, the powder circulation combustible gas generator is arranged below the furnace, a dust collecting and heat exchanging chamber is provided at the bottom of the furnace, an air distribution device is provided between the dust collecting and heat exchanging chamber and the furnace, a plurality of ash collecting funnels evenly distributed around the vertical center line of the dust collecting and heat exchanging chamber are provided at the bottom of the dust collecting and heat exchanging chamber, each ash collecting funnel is in the shape of an inverted cone tube with a larger upper portion and a smaller lower portion, a vertical ash discharge pipe is connected to the lower end of each ash collecting funnel, and an ash discharge valve is provided on each vertical ash discharge pipe, the gas outlet of the cyclone gas-solid separator passes through the dust collecting and heat exchanging chamber through an extension pipeline and leads to the bottom of the furnace,

[0008] The preheating combustion chamber is cylindrical and has a side pipe on the top, which is connected to the inlet of the cyclone gas-solid separator through the side pipe. The top gas outlet of the cyclone gas-solid separator serves as the gas outlet of the powder circulating combustible gas generator and is connected to the dust collecting and heat exchange chamber. The bottom of the cyclone gas-solid separator is connected to the lower part of the preheating combustion chamber through a return device. A primary air chamber is provided at the bottom of the preheating combustion chamber, which is connected to an ignition tube. An ignition spray gun is also provided on the ignition tube. A primary air duct is provided between the primary air chamber and the outlet of the primary fan. A secondary air duct is connected to the side wall of the dust collecting and heat exchange chamber, which is connected to the outlet of the secondary fan. A high-energy igniter is also provided on the ignition spray gun.

[0009] With this design, it was found in the previous test process that when the fuel is residual carbon or the particle size is relatively large or the combustion is not complete, a large amount of ash will accumulate at the bottom of the furnace. When the accumulation reaches a certain level, it will cause heat accumulation, coking of the bottom material, and even excessive temperature of the furnace wall at the bottom of the furnace, which will eventually lead to the need to stop the furnace for coking. Therefore, when there is unstable combustion or unstable pressure in the furnace or preheating combustion chamber, it is necessary to open the ash discharge valve to discharge the ash, quartz sand and other debris accumulated in the ash collecting funnel, and then close the ash discharge valve. At the same time, observe the wind chamber pressure, preheating burner pressure, temperature and cyclone separator inlet temperature. If the wind chamber pressure is lower than 5kPa or the temperature inside the burner differs from the cyclone separator inlet temperature by more than 100 degrees and the burner bottom pressure is less than 1.5kPa, the bed material is too little and the circulation in the cyclone separator is not good. Then, add quartz sand to the sand adding hopper, open the sand adding valve, add quartz sand to the preheating combustion chamber, wait until the preheating combustion chamber and the furnace return to normal pressure difference, and then close the sand adding valve without stopping the furnace.

[0010] Under normal circumstances, quartz sand only exists in the preheating combustion chamber. When the return wind, purge wind or primary wind is too strong, or the wind pressure is unstable, quartz sand may be brought to the bottom of the furnace, causing air flow fluctuations and unstable combustion in the furnace. At the same time, unstable combustion causes incomplete combustion of powder, and quartz sand and ash and other debris accumulate at the bottom of the furnace, which aggravates the air flow fluctuation phenomenon. During use, the inventor found that this is the root cause of the above-mentioned failure after careful research and repeated experiments.

[0011] To this end, the inventor added a dust collecting and heat exchange chamber at the bottom of the furnace, and added an ash collecting funnel, a vertical ash discharge pipe and an ash discharge valve in the dust collecting and heat exchange chamber. After quartz sand, accumulated ash and other debris enter the furnace, they first enter the dust collecting and heat exchange chamber under the action of gravity. This design has the following four advantages.

[0012] 1. When the dust accumulates to a certain height in the dust collecting and heat exchange chamber, it will have an adverse effect on the secondary air, causing unstable combustion, coking, and furnace pressure fluctuations.

[0013] 2. When the combustion is unstable and the furnace pressure fluctuates, just open the ash discharge valve to discharge quartz sand, ash and other debris in time to prevent them from interfering with the feeding and air intake at the bottom of the furnace and eliminate the fault in time.

[0014] 3. Timely discharge of the quartz sand that enters the furnace can prevent the quartz sand and even the subsequent flue from causing unnecessary wear to the furnace and subsequent equipment.

[0015] 4. The preheating combustion chamber produces combustible gas with a temperature of over 800°C - mainly coal gas. Although it cannot come into direct contact with the secondary air, it can be collected in the dust-exchange heat chamber, and further heat the secondary air through thermal radiation, which is more conducive to combustion.

[0016] As an optimization, the outer end of the ignition tube is provided with a plurality of primary air branch pipes, the primary air branch pipes are connected to the primary air duct, the outlet of the primary fan is connected to the primary air chamber through the primary air duct, a plurality of primary air branch pipes and the ignition tube, and the front outlet of the ignition spray gun is located in the ignition tube and downstream of the outlet of the primary air branch pipe. With such a design, during ignition, the flame generated by the ignition spray gun can be blown to the primary air chamber with the help of the primary air, which is convenient for ignition. At the same time, the primary air can also cool the ignition spray gun.

[0017] As an optimization, the front end of the ignition spray gun can be extended into the ignition tube, and the rear end thereof is respectively provided with an oil inlet and a compressed air inlet. The oil inlet is connected to the ignition oil pipe through the oil supply pipe and the quick-cut valve and oil regulating valve connected in series on the oil supply pipe. The equipped compressed air pipe is connected with an atomizing branch pipe, a purge branch pipe, a loosening branch pipe and a return branch pipe. The atomizing branch pipe is provided with an atomizing valve and is connected to the compressed air inlet at the rear end of the ignition spray gun. The purge branch pipe is provided with a purge valve and is connected to the oil supply pipe between the oil regulating valve and the atomizing branch pipe interface; the return branch pipe is provided with a return valve and a flow meter and is connected to the return device. The loosening branch pipe is provided with a loosening valve and a flow meter. Such a design is convenient for ignition and is conducive to fluidizing quartz sand in the preheating combustion chamber.

[0018] As an optimization, two rows of grid tubes are arranged in the dust collecting heat exchange chamber, and the two rows of grid tubes are respectively arranged on both sides of the upper port of the extension pipe. Two blind pipes are respectively connected on the inner side walls of the two grid tubes close to the upper port of the extension pipe. The blind pipe and the connected grid tubes surround the upper port of the extension pipe in the middle. Each grid tube and blind tube has multiple air outlets on the side facing the furnace. Two rows of parallel air ducts are arranged on both sides of the dust collecting heat exchange chamber. Both rows of parallel air ducts are connected to the secondary air ducts, and each grid tube is connected to one or two rows of parallel air ducts to form the air distribution device. Such a design has a simple structure and uniform air distribution.

[0019] As an optimization, the powder circulation combustible gas generator is set on one side or directly below the furnace. The extension pipe is bent twice, passes through the dust collection and heat exchange chamber, and then enters the center of the furnace bottom. The downstream bend on the extension pipe is equipped with a temperature sensor and a pressure sensor. This design makes it easy to install temperature sensors and pressure sensors to monitor the most important parameters - the gas feed temperature and pressure at the bottom of the furnace.

[0020] As an optimization, an auxiliary oil or air gun is also provided on the lower side wall of the furnace, and the auxiliary oil or air gun is connected to the ignition oil pipe through a valve and a pipeline. With such a design, on the one hand, during ignition, the valve can be opened, and oil or natural gas can be sprayed into the furnace through the auxiliary oil or air gun to assist combustion, so that the furnace temperature can be increased as quickly as possible in a short time. Practice has proved that the use of auxiliary oil or air guns can complete the ignition procedure one or two hours in advance; on the other hand, when large-particle powdered fuel appears and cannot be completely converted into coal gas in the preheating combustion chamber, the auxiliary oil or air gun can be opened to add oil to assist combustion to ensure sufficient combustion.

[0021] As an optimization, the steam main pipeline is provided with a plurality of drain pipes and drain valves, the high-pressure water supply pipe is provided with a water inlet valve, the buffer tank is provided with a liquid level gauge, the downstream end of the flue formed by the shell of the tertiary air preheater and the shell of the secondary air preheater are connected in series with a desulfurization tower, a bag dust collector and an induced draft fan in sequence, the outlet of the induced draft fan is connected with the chimney through a pipeline, the ignition tube is provided with an observation window, and the observation window is provided with high-temperature resistant glass, the primary fan, secondary fan, tertiary fan, powder delivery fan and induced draft fan are all driven by a variable frequency motor, and the air volume of each fan is controlled by adjusting the speed of the variable frequency motor, a temperature sensor and a pressure sensor are provided on the primary air chamber, a pressure sensor, an oxygen content sensor and a temperature sensor are provided on the upper part or the top of the furnace, an upper temperature sensor, a middle temperature sensor and a lower temperature sensor are provided on the side walls of the preheating combustion chamber, respectively, and a pressure gauge and a pressure sensor are provided at the outlet of the powder delivery fan,

[0022] A video tube is provided in the middle part / or the upper part of the furnace, a fire detection camera is provided at the outer end of the video tube, and a high temperature resistant glass sealing plate is provided at the front end of the video tube. A purge pipe pointing to the inner side of the high temperature resistant glass sealing plate is also provided on the furnace wall on one side of the video tube, and the purge pipe is connected to the equipped compressed air pipe through a purge valve. With such a design, when dust accumulates on the high temperature resistant glass sealing plate, the purge valve can be opened to blow away the dust on the inner side of the high temperature resistant glass sealing plate through the purge pipe, which is convenient for control and observation.

[0023] As an optimization, a front electric damper is also provided on the flue upstream of the desulfurization tower, and a circulating flue gas pipe is provided on the flue upstream of the front electric damper. The circulating flue gas pipe is connected to the secondary air pipe through a circulating flue gas fan, a circulating flue gas electric damper, and a flow meter. With such a design, since the main component of the flue gas is non-combustible gas such as CO2, and the oxygen content is below 5%, the introduction of this air into the furnace is mainly to reduce the secondary air volume, thereby reducing the oxygen content in the furnace, allowing NO to react in an oxygen-deficient environment and be reduced to nitrogen, thereby reducing NO in the flue gas. X concentration.

[0024] As an optimization, it also includes a programmable controller, a memory and a touch screen, the memory and the touch screen are respectively connected to the programmable controller, all valves are electric valves, all electric valves and all frequency conversion motors of fans are connected to the control signal output end of the programmable controller, and all temperature sensors, pressure sensors, flow meters, liquid level meters, oxygen content sensors and fire detection cameras are connected to the signal input end of the programmable controller. Such a design is convenient for control by the programmable controller, automatic ignition, and automatic operation.

[0025] The method for using the vertical powder boiler system of the present invention comprises the following steps:

[0026] 1. Preparation before ignition

[0027] ①. The buffer tank is filled with water and the conditions for ignition are met.

[0028] ②. Install the ignition spray gun in place and check the fire detection camera.

[0029] ③. Open the sand adding valve and add quartz sand into the preheating combustion chamber through the sand adding hopper, so that the quartz sand naturally accumulates 50-70 cm high in the preheating combustion chamber.

[0030] ④. Open the return valve and loosening valve, and make the return air velocity reach twice the loosening air velocity (the return air volume is 40M 3 / h, adjust the loose air volume to 20M 3 / h),

[0031] ⑤. Start the primary fan, and use the introduction of primary air to make the quartz sand in the preheating combustion chamber reach a fluidized state. Turn on and adjust the induced draft fan to keep the pressure on the upper part or top of the furnace at 0~-100Pa.

[0032] ⑥. If this ignition is the first ignition of this vertical powder boiler system, start the powder delivery fan and adjust the speed of the powder delivery fan to 10% of its full load speed. If not, go directly to the next step.

[0033] ⑦. Furnace purge, start the induced draft fan, secondary fan, and tertiary fan, and make the secondary fan and tertiary fan rotate at 30% of their full load speed to purge the furnace. Purge for 5-10 minutes, and adjust the speed of the secondary fan to 15% of its full load speed (4000 M 3 / h), adjust the speed of the tertiary fan to 10% of its full load speed (3000 M 3 / h),

[0034] ⑧. Adjust the primary fan speed slowly to about 40% of its full load speed (wind speed about 1200 M 3 / h), so that the quartz sand in the preheating combustion chamber is kept in a fluidized state, and the speed of the induced draft fan is adjusted to keep the pressure in the furnace at 0-100Pa.

[0035] 2. Oil ignition:

[0036] (1). Open the purge valve and atomizing valve for 1 minute, then close the purge valve. After closing the purge valve, start the high-energy igniter, open the quick-cut valve and the oil regulating valve at the same time. After 10 seconds, the high-energy igniter will be automatically cut off. At this time, the fire detection probe can be used to observe whether there is an open flame at the front end of the ignition oil mist (natural gas) spray gun. If not, it means that the ignition has failed. It is necessary to quickly close the quick-cut valve and the oil (natural gas) regulating valve, open the purge valve, and purge. After 1 minute of purge, close the purge valve and repeat this step until an open flame appears at the front end of the ignition oil mist (natural gas) spray gun. Ignition is successful.

[0037] (2) After successful ignition, keep the fuel regulating valve open at 30% and gradually increase the primary fan speed to 50-70% of its full load speed to keep the primary air chamber temperature below 850°C; continue to increase the temperature and control the temperature increase rate of the preheating combustion chamber below 400°C / h.

[0038] 3. Powder ignition:

[0039] ①. If it is the first ignition, go directly to the next step. If it is not the first ignition, after the ignition is successful, start the powder delivery fan and slowly open it to about 10%;

[0040] ②. When the preheated combustion chamber temperature reaches 600℃ (±50℃), restart the furnace purge procedure:

[0041] Start the induced draft fan, secondary fan, and tertiary fan, adjust the frequency conversion motors driving the secondary and tertiary fans, so that the corresponding fans rotate at 30% of their full load speed, and purge the furnace for 5-10 minutes. Adjust the speed of the secondary fan to 15% of its full load speed (4000 M 3 / h), adjust the speed of the tertiary fan to 10% of its full load speed (3000 M 3 / h),

[0042] After the purge is completed, start the screw feeder or rotary valve and make the speed of the screw feeder or rotary valve reach 5% of its full load speed, adjust the speed of the powder feeding fan to 45% of its full load speed, adjust the speed of the primary fan to 65% of its full load speed, adjust the speed of the secondary fan to 15% of its full load speed, adjust the speed of the tertiary fan to 10% of its full load speed, and adjust the speed of the induced draft fan to 20% of its full load speed, and continue to burn and heat up.

[0043] ③. When the temperature of the preheating combustion chamber rises to 700-800℃, and the temperature difference between any two of the temperature parameters sensed by the upper, middle and lower temperature sensors of the preheating combustion chamber does not exceed 50℃, and the operation is stable, close the quick-cut valve and the oil regulating valve, and stop using the ignition spray gun.

[0044] ④. When the temperature sensor on the rear elbow senses a temperature of about 700°C, the temperature sensor on the upper or top of the furnace senses a temperature of 70-80°C, and the temperatures sensed by the upper, middle and lower temperature sensors of the preheating combustion chamber are all within the range of 850-900°C, add auxiliary oil or air gun to the lower part of the furnace. When the temperature measurement point at the lower part of the furnace reaches 300 degrees, try to add combustible powder. When the fire detection probe shows fire, stop the auxiliary oil or air gun. Try to add combustible powder, gasify and run, and enter the furnace ignition stage;

[0045] Specific steps:

[0046] 1). By adjusting the speed of the secondary fan, tertiary fan and induced draft fan, the pressure at the top of the furnace is kept within the range of -90 to -110 Pa;

[0047] 2) Start the auxiliary oil or air gun at the bottom of the furnace. When the temperature at the temperature measuring point at the bottom of the furnace reaches about 300°C, try to put in combustible powder. When the fire detection probe shows fire, stop the auxiliary oil or air gun.

[0048] 3). Adjust the speed of the powder delivery fan to 80% of its full load speed, observe whether the outlet pressure of the powder delivery fan reaches the design pressure, and observe the temperature rise of the preheating combustion chamber. If there is fire in the furnace within 60 seconds, the oxygen content decreases, and a small positive pressure appears, it can be judged that the combustible powder is ignited normally. If there is no fire within 60 seconds, the screw feeder or rotary valve and powder delivery fan should be stopped immediately, and the furnace should be purged.

[0049] Start the induced draft fan, secondary fan, and tertiary fan, adjust the frequency conversion motors driving the secondary and tertiary fans, so that the corresponding fans rotate at 30% of their full load speed, and purge the furnace for 5-10 minutes. Adjust the speed of the secondary fan to 15% of its full load speed (4000 M 3 / h), adjust the speed of the tertiary fan to 10% of its full load speed (3000 M 3 / h), and then re-ignite the combustible powder after an interval of more than 10 minutes until the fire is normal;

[0050] 4. Powder ignition completes subsequent work:

[0051] ①. After the combustible powder is ignited normally, the speed of the secondary fan should be immediately adjusted to 30-35% of its full load speed, and the speed of the tertiary fan should be adjusted to 20-25% of its full load speed, so that the oxygen content in the furnace is maintained within the range of 2-6%. According to the steam pressure rise of the main steam pipeline, the water level and steam temperature of the buffer tank should be controlled;

[0052] ②. After the combustible powder is ignited normally, when the flue gas temperature reaches above 90°C, immediately contact the follow-up personnel to put the desulfurization tower and bag filter into use to ensure that the environmental protection parameters do not exceed the standard;

[0053] ③. From the initial stage of ignition of combustible powder to the entire operation period, monitor the temperature of the preheating combustion chamber to ensure that the temperatures sensed by the upper, middle and lower temperature sensors on the preheating combustion chamber are maintained at 800-950℃. When the temperature is high, appropriately reduce the amount of combustible powder input; when the temperature is low, appropriately increase the amount of combustible powder input, and appropriately increase the air volume of the primary, secondary and tertiary air to ensure that the combustible powder is fully burned. With this design, after ignition, the operation is stable, the powder is fully burned, and it is environmentally friendly and energy-saving.

[0054] The vertical powder-fuel boiler system of the present invention runs more smoothly and can use coal powder, charcoal powder, residual carbon, semi-coke, anthracite and sawdust powder or any combustible powder. When unstable combustion and unstable furnace pressure occur, the vertical powder-fuel boiler can be quickly restored to normal through simple ash discharge and sand addition operations. The vertical powder-fuel boiler is suitable for serving as various industrial and domestic boilers such as power plant boilers and central heating boilers. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The vertical powder boiler system and its use method of the present invention are further described below in conjunction with the accompanying drawings:

[0056] Figure 1 This is a schematic diagram of the process equipment of the first implementation mode of the vertical powder boiler system;

[0057] Figure 2 yes Figure 1 The schematic diagram of the upstream process equipment of the vertical powder boiler system is shown;

[0058] Figure 3 yes Figure 1 The schematic diagram of the downstream process equipment of the vertical powder boiler system is shown;

[0059] Figure 4 It is a schematic diagram of the vertical cross-section structure of the powder circulating combustible gas generator, dust collecting heat exchange chamber and furnace bottom of the first embodiment of the vertical powder boiler system;

[0060] Figure 5 yes Figure 4 The schematic diagram of the top view of the powder circulation combustible gas generator, dust collection heat exchange chamber and furnace bottom and other equipment shown;

[0061] Figure 6 yes Figure 5 The schematic diagram of the positional relationship between the two rows of parallel air ducts and the grid pipes, blind pipes and upper ends of the extended pipes therebetween;

[0062] Figure 7 This is a flow chart of the second implementation method of the vertical powder boiler system;

[0063] Figure 8 yes Figure 7 Schematic diagram of upstream equipment of implementation method 2 of the neutral powder boiler system.

[0064] In the figure: 1 is the furnace, 2 is the powder circulation combustible gas generator, 3 is the powder delivery fan, 4 is the primary fan, 5 is the secondary fan, 6 is the powder storage bin, 7 is the dust collection heat exchange chamber, 8 is the ash collection funnel, 9 is the vertical ash discharge pipe, 10 is the ash discharge valve, 11 is the primary air chamber, 12 is the ignition tube, 13 is the ignition spray gun, 14 is the primary air duct, 15 is the secondary air duct, 16 is the high energy igniter, 17 is the primary Wind branch pipe, 18 is oil supply pipe, 19 is waste heat boiler, 20 is quick cut valve, 21 is preheating combustion chamber, 211 is fuel powder feeding pipe, 212 is sand adding pipe, 213 is feeding pipe, 214 is sand adding hopper, 215 is sand adding valve, 216 is screw feeder, 217 is extension pipeline, 22 is cyclone gas-solid separator, 23 is return feeder, 24 is oil regulating valve, 25 is atomizing branch pipe, 26 is The purge branch pipe, 27 is a loose branch pipe, 28 is a return branch pipe, 29 is an atomizing valve, 30 is a purge valve, 31 is a return valve, 32 is a flow meter, 33 is a loose valve, 34 is a plurality of preheated water heat exchangers, 35 is a buffer tank, 36 is a domestic water heat exchanger, 37 is a tertiary air preheater, 38 is a secondary air preheater, 39 is a tertiary air duct, 40 is a tertiary fan, 41 is a desulfurization tower, 42 is a bag filter, 43 is an induced draft fan, 44 is a matching chimney, 45 is a front electric damper, 46 is a circulating flue gas pipe, 47 is a circulating flue gas fan, 48 is a circulating flue gas electric damper, 49 is a high temperature resistant glass, 50 is a reserved threaded hole on the extension pipe for installing a temperature sensor and a pressure sensor, 51 is a parallel air duct, 52 is a grid pipe, 53 is a blind pipe, 54 is an air outlet, and 55 is an auxiliary oil or air gun. DETAILED DESCRIPTION

[0065] Implementation method 1: Figure 1-6 As shown, the vertical powder boiler system includes a furnace 1, a powder circulating combustible gas generator 2, a powder feeding fan 3, a primary fan 4, a secondary fan 5 and a flue, wherein the furnace 1 is cylindrical, and the powder circulating combustible gas generator 2 includes a preheating combustion chamber 21, a cyclone gas-solid separator 22 and a returner 23, which are sequentially connected in series to form a circulating fluidized bed type gas generating device, and a fuel powder feeding pipe 211 and a sand adding pipe 212 are provided on the lower side wall of the preheating combustion chamber 21, wherein the fuel powder feeding pipe 211 is connected to the outlet of the powder feeding fan 3, and a feeding pipe 213 is also provided on the fuel powder feeding pipe 211, and the feeding pipe 213 is connected to the discharge port at the bottom of the powder silo 6 through a screw feeder 216 (of course, the screw feeder 2016 can also be replaced by a rotary valve, which is omitted), and a sand adding hopper 214 is provided on the top of the sand adding pipe 212, and a sand adding valve 215 is provided.

[0066] It is characterized in that: a pressure sensor or a pressure gauge is provided on the upper part or the top of the furnace 1, the powder circulation combustible gas generator 2 is arranged below the furnace 1, a dust collecting and heat exchanging chamber 7 is provided at the bottom of the furnace 1, an air distribution device is provided between the dust collecting and heat exchanging chamber 7 and the furnace 1, and a plurality of ash collecting funnels 8 are provided at the bottom of the dust collecting and heat exchanging chamber 7, which are evenly distributed around the vertical center line of the dust collecting and heat exchanging chamber 7, each ash collecting funnel 8 is in the shape of an inverted cone tube with a large top and a small bottom, and a vertical ash discharge pipe 9 is connected to the lower end of each ash collecting funnel 8, and an ash discharge valve 10 is provided on each vertical ash discharge pipe 9. The gas outlet of the cyclone gas-solid separator 22 passes through the dust collecting and heat exchanging chamber 7 through the extension pipe 217 and enters the bottom of the furnace 1.

[0067] The preheating combustion chamber 21 is cylindrical, and a side pipe is provided on the top thereof, and is communicated with the inlet of the cyclone gas-solid separator 22 through the side pipe. The top gas outlet of the cyclone gas-solid separator 22 serves as the gas outlet of the powder circulating combustible gas generator 2 and is communicated with the dust collecting and heat exchange chamber 7. The bottom of the cyclone gas-solid separator 22 is communicated with the lower part of the preheating combustion chamber 21 through a return device 23. A primary air chamber 11 is provided at the bottom of the preheating combustion chamber 21, and the primary air chamber 11 is connected to an ignition tube 12. An ignition spray gun 13 is also provided on the ignition tube 12. A primary air duct 14 is provided between the primary air chamber 11 and the outlet of the primary fan 4. A secondary air duct 15 is connected to the side wall of the dust collecting and heat exchange chamber 7. The secondary air duct 15 is communicated with the outlet of the secondary fan 5. A high-energy igniter 16 is also provided on the ignition spray gun 13.

[0068] A plurality of primary air branch pipes 17 are provided at the outer end of the ignition tube 12, and the primary air branch pipes 17 are communicated with the primary air duct 14. The outlet of the primary fan 4 is communicated with the primary air chamber 11 through the primary air duct 14, a plurality of primary air branch pipes 17 and the ignition tube 12. The front end outlet of the ignition spray gun 13 is located in the ignition tube 12 and downstream of the outlet of the primary air branch pipe 17.

[0069] The front end of the ignition spray gun 13 can be extended into the ignition tube 12, and the rear end thereof is respectively provided with an oil inlet and a compressed air inlet. The oil inlet is communicated with the matching ignition oil pipe through the oil supply pipe 18 and the quick-cut valve 20 and the oil regulating valve 24 connected in series on the oil supply pipe 18. The matching compressed air pipe is connected with an atomizing branch pipe 25, a purge branch pipe 26, a loosening branch pipe 27 and a return branch pipe 28. The atomizing branch pipe 25 is provided with an atomizing valve 29 and is communicated with the compressed air inlet at the rear end of the ignition spray gun 13. The purge branch pipe 26 is provided with a purge valve 30 and is communicated with the oil supply pipe 18 between the interface of the oil regulating valve 24 and the atomizing branch pipe 25; the return branch pipe 28 is provided with a return valve 31 and a flow meter 32, and is communicated with the return device 23, and the loosening branch pipe 27 is provided with a loosening valve 33 and a flow meter 32.

[0070] A two-stage linkage screw feeder 216 is provided between the feeding pipe 213 and the discharge port at the bottom of the powder silo 6. This facilitates the feeding of the combustible powder on the one hand, and prevents the powder delivery wind from blowing back into the combustible powder silo for use on the other hand.

[0071] A waste heat boiler 19 and a plurality of preheated water heat exchangers 34 are provided between the furnace 1 and the flue. The plurality of preheated water heat exchangers are provided with heat exchange coils (not shown in the figure). The waste heat boiler 19 and the shells of the plurality of preheated water heat exchangers 34 are connected in series to form a part of the flue. A buffer tank 35 is provided on the top of the waste heat boiler. A safety valve and a vent valve are provided on the top of the buffer tank 35. A plurality of heat exchange tubes are provided in the waste heat boiler 19. One end of the heat exchange tube is communicated with the bottom of the buffer tank 35, and the other end is communicated with the main steam pipeline (not shown in the figure).

[0072] The heat exchange coils of the multiple groups of preheating water heat exchangers 34 are connected in sequence to form a preheating water pipe (not shown in the figure). One end of the preheating water pipe is connected to the buffer tank 35, and the other end of the preheating water pipe is connected to the high-pressure water supply pipe (not shown in the figure) through the water inlet valve. The gas flow direction of the flue is opposite to the water flow in the preheating water pipe, and the two exchange heat in reverse.

[0073] At the downstream end of the flue formed by connecting the shells of multiple groups of preheating water heat exchangers 34 in series, multiple groups of domestic water heat exchangers 36 are arranged in sequence. The shells of the domestic water heat exchangers 36 are connected in series to form a part of the flue. Each domestic water heat exchanger 36 is provided with a heat exchange coil (not shown in the figure). The heat exchange coils are connected in series with each other. A shut-off valve (not shown in the figure) is arranged between adjacent heat exchange coils. Inlet and outlet water pipes (not shown in the figure) are arranged on both sides of the shut-off valve, and each inlet and outlet water pipe is provided with a valve (not shown in the figure). The heat exchange coils can be connected in series between the upper water pipe (not shown in the figure) and the lower water pipe (not shown in the figure), or they can be connected to the upper water pipe (not shown in the figure) and the lower water pipe (not shown in the figure) respectively, so as to provide winter heating water and / or bathing water.

[0074] The downstream end of the flue formed by connecting the shells of multiple groups of domestic water heat exchangers 36 in series is provided with a tertiary air preheater 37 and a secondary air preheater 38 in sequence. The tertiary air preheater 38 and the secondary air preheater 37 are provided with heat exchange coils (not shown in the figure). The shells of the tertiary air preheater 38 and the shells of the secondary air preheater 38 are connected in series to form a part of the flue. A plurality of tertiary air ducts 39 are provided on the side wall of the furnace 1. The tertiary air ducts 39 are connected to one end of the heat exchange pipe of the tertiary air preheater 38 through the tertiary air main pipe. The other end of the heat exchange pipe of the tertiary air preheater is connected to the outlet of a tertiary fan 40. The heat exchange coil in the secondary air preheater is connected in series between the secondary fan 5 and the secondary air duct 45. In this way, the waste heat of flue gas can be fully utilized, which is energy-saving and environmentally friendly.

[0075] The steam main pipeline is provided with a plurality of drain pipes and drain valves (not shown in the figure), the high-pressure water supply pipe is provided with a water inlet valve (not shown in the figure), the buffer tank 35 is provided with a liquid level gauge (not shown in the figure), the shell of the tertiary air preheater 38 and the shell of the secondary air preheater 37 are connected in series to form a flue, and the downstream end is connected with a desulfurization tower 41, a bag filter 42, and an induced draft fan 43 in sequence, and the outlet of the induced draft fan 43 is connected to the chimney 44 through a pipeline, and the ignition tube 12 is provided with an observation window, and the observation window is provided with a high temperature resistant glass 49 The primary fan 4, secondary fan 5, tertiary fan 40, powder delivery fan 3, and induced draft fan 43 are all driven by variable frequency motors. The air volume of each fan is controlled by adjusting the speed of the variable frequency motor. A temperature sensor and a pressure sensor are provided on the primary air chamber 11. A pressure sensor, an oxygen content sensor, and a temperature sensor are provided on the upper or top part of the furnace 1. An upper temperature sensor, a middle temperature sensor, and a lower temperature sensor (not shown in the figure) are provided on the side walls of the preheating combustion chamber 21, respectively. A pressure gauge and a pressure sensor are provided at the outlet of the powder delivery fan 3.

[0076] A camera tube is provided in the middle and / or upper part of the furnace 1, a fire detection camera is provided at the outer end of the camera tube (not shown in the figure), and a high-temperature resistant glass sealing plate is provided at the front end of the camera tube (not shown in the figure), and a purge pipe (not shown in the figure) pointing to the inner side of the high-temperature resistant glass sealing plate is provided on the furnace wall on one side of the camera tube. The purge pipe is connected to a compressed air pipe through a purge valve (not shown in the figure).

[0077] A front electric damper 45 is also provided on the flue upstream of the desulfurization tower 41 , and a circulating flue gas pipe 46 is provided on the flue upstream of the front electric damper 45 . The circulating flue gas pipe 46 is connected to the secondary air duct 15 through a circulating flue gas fan 47 , a circulating flue gas electric damper 48 , and a flow meter 32 .

[0078] The powder circulation combustible gas generator 2 is arranged on one side below the furnace. The extension pipe 217 is bent twice, passes through the dust collecting and heat exchange chamber 7, and then enters the bottom center of the furnace 1. A temperature sensor and a pressure sensor are provided at the downstream bend on the extension pipe 217. Figure 4 Reference numeral 50 is a reserved threaded hole on the extended pipe for installing a temperature sensor and a pressure sensor.

[0079] Two rows of grid tubes 52 are provided in the dust collecting and heat exchanging chamber 7, and the two rows of grid tubes 52 are respectively arranged on both sides of the upper end of the extension pipe 217, and two blind pipes 53 are respectively connected on the inner walls of the two grid tubes 52 close to the upper end of the extension pipe 217. The blind pipes 53 and the grid tubes 52 connected thereto surround the upper end of the extension pipe 217 in the middle, and each grid tube 52 and the blind tube 53 are provided with a plurality of air outlet holes 54 on the side facing the furnace 1, and two rows of parallel air ducts 51 are provided on both sides of the dust collecting and heat exchanging chamber 7, and the two rows of parallel air ducts 51 are communicated with the secondary air duct 15, and each grid tube 51 is communicated with one or two rows of parallel air ducts 51, forming the air distribution device.

[0080] Note: Figure 4-6 The extension pipe 217 on the Figure 1 , 2 The extension pipe 217 on the Figure 1 , 2 The bend of the extension pipe 217 is a rounded elbow. Figure 4-6 There is no contradiction in using a right-angle elbow at the bend of the extension pipe 217.

[0081] Implementation method 2: Figure 7 , 8 As shown, the powder circulation combustible gas generator 22 is arranged directly below the furnace 1. The ash collecting funnel 8, the vertical ash discharge pipe 9, and the ash discharge valve 10 are arranged on the dust collecting heat exchange chamber 7 around the vertical center of the dust collecting heat exchange chamber 7. An auxiliary oil or air gun 55 is also provided on the lower side wall of the furnace 1. The auxiliary oil or air gun 55 is connected to the ignition oil pipe through a valve and a pipeline, and the figure is omitted. The remaining structures are as described in the embodiment 1 and are omitted.

[0082] Implementation method three: It also includes a programmable controller (not shown in the figure), a memory (not shown in the figure) and a touch screen (not shown in the figure). The memory and the touch screen are respectively connected to the programmable controller. All valves are electric valves. All electric valves and all frequency conversion motors of fans are connected to the control signal output end of the programmable controller. All temperature sensors, pressure sensors, flow meters, liquid level meters, oxygen content sensors and fire detection cameras are connected to the signal input end of the programmable controller. The remaining structures are as described in Implementation method one, and the figure is omitted.

[0083] The method for using the vertical powder feed boiler system according to the first embodiment of the present invention comprises the following steps:

[0084] 1. Preparation before ignition

[0085] ①. Open the air release valve and water inlet valve on the buffer tank 35, fill water into the buffer tank 35 so that the water volume inside reaches 40-50% of the total volume of the buffer tank 35, and open each steam trap.

[0086] ②. Install the ignition spray gun 13 in place and check the fire detection camera.

[0087] ③. Open the sand adding valve 215 and add quartz sand to the preheating combustion chamber 21 through the sand adding hopper 214, so that the quartz sand naturally accumulates 50-70 cm high in the preheating combustion chamber 21.

[0088] ④. Open the return valve 31 and the loosening valve 33, and make the return air velocity reach twice the loosening air velocity (the return air volume is 40M 3 / h, adjust the loose air volume to 20M 3 / h),

[0089] ⑤. Start the primary fan 4, and with the help of the introduction of primary air, make the quartz sand in the preheating combustion chamber 21 reach a fluidized state, start and adjust the induced draft fan 43, so that the pressure on the upper part or top of the furnace 1 is maintained at 0-100Pa,

[0090] ⑥. If this ignition is the first ignition of this vertical powder boiler system, start the powder delivery fan 3 and adjust the speed of the powder delivery fan 3 to 10% of its full load speed;

[0091] If it is not the first time to ignite, go directly to the next step.

[0092] ⑦. Purge the furnace 1, start the induced draft fan 43, the secondary fan 5, and the tertiary fan 40, and make the secondary fan 5 and the tertiary fan 40 rotate at 30% of their full load speed, and purge the furnace 1 for 5-10 minutes, and adjust the speed of the secondary fan 5 to 15% of its full load speed (4000 M 3 / h), adjust the speed of the tertiary fan 40 to 10% of its full load speed (3000 M 3 / h),

[0093] ⑧. Adjust the speed of primary fan 4 and slowly increase it to about 40% of its full load speed (wind speed is about 1200 M 3 / h), so that the quartz sand in the preheating combustion chamber 21 is kept in a fluidized state, and the speed of the induced draft fan 43 is adjusted to keep the pressure in the furnace 1 within the range of 0-minus 100Pa.

[0094] 2. Oil ignition:

[0095] (1). Open the purge valve 30 and the atomizing valve 29 to purge for 1 minute, then close the purge valve 30. After closing the purge valve 30, start the high-energy igniter, open the quick-cut valve 20 and the fuel regulating valve 24 at the same time. After 10 seconds, the high-energy igniter 16 is automatically cut off. At this time, the staff observes through the observation window whether there is an open flame at the front end of the ignition spray gun 13. If not, it means that the ignition has failed. It is necessary to quickly close the quick-cut valve 20 and the fuel regulating valve 24, open the purge valve 30, and purge. After 1 minute of purge, close the purge valve 30 and repeat this step until an open flame appears at the front end of the ignition spray gun 13. The ignition is successful.

[0096] (2) After successful ignition, keep the opening of the fuel regulating valve 24 at 30% and increase the speed of the primary fan 4 to 50-70% of its full load speed to keep the temperature of the primary air chamber 11 below 850°C; continue to increase the temperature and control the temperature increase rate of the preheating combustion chamber 21 below 400°C / h.

[0097] 3. Powder ignition:

[0098] ①. If it is the first ignition, go directly to the next step. If it is not the first ignition, after the ignition is successful, start the powder delivery fan 3 and slowly open it to about 10%;

[0099] ②. When the preheated combustion chamber temperature reaches 600℃ (±50℃), restart the furnace purge procedure:

[0100] Start the induced draft fan 43, the secondary fan 5, and the tertiary fan 40, and adjust the frequency conversion motors driving the secondary fan 5 and the tertiary fan 40 so that the corresponding fans rotate at 30% of their respective full-load speeds, and purge the furnace 1 for 5-10 minutes, and adjust the speed of the secondary fan 5 to 15% of its full-load speed (4000 M 3 / h), adjust the speed of the tertiary fan 40 to 10% of its full load speed (3000 M 3 / h),

[0101] After the purge is completed, the screw feeder 216 is started to adjust its speed to 5% of its full load speed, the speed of the powder feeding fan 3 is adjusted to 45% of its full load speed, the speed of the primary fan 4 is adjusted to 65% of its full load speed, the speed of the secondary fan 5 is adjusted to 15% of its full load speed, the speed of the tertiary fan 40 is adjusted to 10% of its full load speed, and the speed of the induced draft fan 43 is adjusted to 20% of its full load speed, and the combustion and temperature increase continue.

[0102] ③. When the temperature of the preheating combustion chamber 21 rises to 700-800°C, and the temperature difference between any two temperatures in the temperature parameters sensed by the upper, middle and lower temperature sensors of the preheating combustion chamber 21 does not exceed 50°C, and the operation is stable, close the quick-cut valve 20 and the oil regulating valve 24, and stop the ignition gun 13.

[0103] ④. When the temperature sensor on the rear elbow senses a temperature of about 700°C, the temperature sensor on the upper or top of the furnace 1 senses a temperature of 70-80°C, and the temperatures sensed by the upper, middle and lower temperature sensors of the preheating combustion chamber 21 are all within the range of 850-900°C, add the auxiliary oil or air gun 55. When the temperature measurement point at the lower part of the furnace reaches 300 degrees, try to add combustible powder. When the fire detection in the furnace shows fire, stop feeding the auxiliary oil or air gun 55. Try to add combustible powder, gasify and run, and enter the ignition stage of the furnace 1;

[0104] Specific steps:

[0105] 1). By adjusting the speed of the secondary fan 5, the tertiary fan 40 and the induced draft fan 43, the pressure at the top of the furnace 1 is maintained in the range of -90 to -110 Pa; 2) Start the auxiliary oil or air gun 55 at the lower part of the furnace. When the temperature of the temperature measuring point at the lower part of the furnace reaches about 300°C, try to add combustible powder. When the fire detection in the furnace shows fire, stop the auxiliary oil or air gun 55.

[0106] 3). Adjust the speed of the powder delivery fan 3 to 80% of its full load speed, observe whether the outlet pressure of the powder delivery fan 3 reaches the design pressure, and observe the temperature rise of the preheating combustion chamber 21. If there is fire in the furnace within 60 seconds, the oxygen content decreases, and a small positive pressure appears, it can be judged that the combustible powder is ignited normally. If there is no fire within 60 seconds, the screw feeder 216 and the powder delivery fan 3 should be stopped immediately, and the furnace 1 should be purged.

[0107] Start the induced draft fan 43, the secondary fan 5, and the tertiary fan 40, and adjust the frequency conversion motors driving the secondary fan 5 and the tertiary fan 40 so that the corresponding fans rotate at 30% of their respective full-load speeds, and perform furnace purge for 5-10 minutes. Adjust the speed of the secondary fan 5 to 15% of its full-load speed (4000 M 3 / h), adjust the speed of the tertiary fan 40 to 10% of its full load speed (3000 M 3 / h), and then re-ignite the combustible powder after an interval of more than 10 minutes until the fire is normal;

[0108] 4. Powder ignition completes subsequent work:

[0109] ①. After the combustible powder is ignited normally, the speed of the secondary fan 5 should be immediately adjusted to 30-35% of its full load speed, and the speed of the tertiary fan 40 should be adjusted to 20-25% of its full load speed, so that the oxygen content in the furnace is maintained within the range of 2-6%. According to the steam pressure rise of the steam main pipeline, the water level and steam temperature of the buffer tank 35 should be controlled;

[0110] ②. After the combustible powder is ignited normally, when the flue gas temperature reaches above 90°C, immediately contact the follow-up personnel to put the desulfurization tower 41 and the bag filter 42 into use to ensure that the environmental protection parameters do not exceed the standard;

[0111] ③. From the initial stage of ignition of the combustible powder to the entire operation period, the temperature of the preheating combustion chamber 21 is monitored to ensure that the temperatures sensed by the upper, middle and lower temperature sensors on the preheating combustion chamber 21 are maintained at 800-950°C. When the temperature is high, the amount of combustible powder input is appropriately reduced; when the temperature is low, the amount of combustible powder input is appropriately increased. At the same time, the air volume of the primary air, secondary air and tertiary air is appropriately increased to ensure sufficient combustion of the combustible powder.

Claims

1. A vertical powder boiler system, comprising a furnace, a powder circulating combustible gas generator, a powder feeding fan, a primary fan, a secondary fan and a flue, wherein the furnace is cylindrical, the powder circulating combustible gas generator comprises a preheating combustion chamber, a cyclone gas-solid separator and a returner, the three of which are connected in series to form a circulating fluidized bed type gas generating device, a fuel powder feeding pipe and a sand adding pipe are provided on the lower side wall of the preheating combustion chamber, wherein the fuel powder feeding pipe is connected to the outlet of the powder feeding fan, and a feeding pipe is also provided on the fuel powder feeding pipe, the feeding pipe is connected to the discharge port at the bottom of the powder bunker through a screw feeder or a rotary valve, a sand adding hopper is provided on the top of the sand adding pipe, and a sand adding valve is provided, wherein: The furnace is provided with a pressure sensor or a pressure gauge, the powder circulation combustible gas generator is arranged below the furnace, a dust collecting and heat exchanging chamber is provided at the bottom of the furnace, an air distribution device is provided between the dust collecting and heat exchanging chamber and the furnace, a plurality of ash collecting funnels evenly distributed around the vertical center line of the dust collecting and heat exchanging chamber are provided at the bottom of the dust collecting and heat exchanging chamber, each ash collecting funnel is in the shape of an inverted cone tube with a larger upper portion and a smaller lower portion, a vertical ash discharge pipe is connected to the lower end of each ash collecting funnel, and an ash discharge valve is provided on each vertical ash discharge pipe, the gas outlet of the cyclone gas-solid separator passes through the dust collecting and heat exchanging chamber through an extension pipeline and leads to the bottom of the furnace, The preheating combustion chamber is cylindrical in shape, and a side pipe is provided on the top thereof, which is communicated with the inlet of the cyclone gas-solid separator through the side pipe. The top gas outlet of the cyclone gas-solid separator serves as the gas outlet of the powder circulating combustible gas generator and is communicated with the dust collecting and heat exchange chamber. The bottom of the cyclone gas-solid separator is communicated with the lower part of the preheating combustion chamber through a return device. A primary air chamber is provided at the bottom of the preheating combustion chamber, and the primary air chamber is connected to an ignition tube. An ignition spray gun is also provided on the ignition tube. A primary air duct is provided between the primary air chamber and the outlet of the primary fan. A secondary air duct is connected to the side wall of the dust collecting and heat exchange chamber, and the secondary air duct is communicated with the outlet of the secondary fan. A high-energy igniter is also provided on the ignition spray gun. A plurality of primary air branch pipes are provided at the outer end of the ignition tube, and the above-mentioned primary air branch pipes are communicated with the primary air duct. The outlet of the primary fan is connected to a primary air duct through the primary air duct, a plurality of primary air branch pipes and the ignition tube. The secondary air chamber is connected, and the front end outlet of the ignition spray gun is located in the ignition tube and downstream of the primary air branch pipe outlet. Two rows of grid tubes are arranged in the dust collecting and heat exchanging chamber, and the two rows of grid tubes are respectively arranged on both sides of the upper port of the extension pipe. Two blind pipes are connected on the inner walls of the two grid tubes close to the upper port of the extension pipe, and the blind pipes and the grid tubes connected thereto surround the upper port of the extension pipe in the middle. Each grid tube and the blind pipe have a plurality of air outlets on the side facing the furnace. Two rows of parallel air ducts are arranged on both sides of the dust collecting and heat exchanging chamber, and the two rows of parallel air ducts are connected to the secondary air duct. Each grid tube is connected to one or two rows of parallel air ducts to form the air distribution device. The powder circulation combustible gas generator is arranged on one side or directly below the furnace. The extension pipe is bent twice, passes through the dust collecting and heat exchanging chamber, and then enters the center of the bottom of the furnace. A temperature sensor and a pressure sensor are provided at the downstream bend on the extension pipe.

2. The vertical powder boiler system according to claim 1 is characterized in that: The front end of the ignition spray gun extends into the ignition tube, and the rear end thereof is respectively provided with a fuel inlet and a compressed air inlet. The fuel inlet is communicated with the matching ignition fuel pipe through the oil supply or Tianene air pipe and the quick-cut valve and the fuel regulating valve connected in series on the oil supply or Tianene air pipe. The matching compressed air pipe is connected with an atomizing branch pipe, a purge branch pipe, a loosening branch pipe and a return branch pipe. The atomizing branch pipe is provided with an atomizing valve and is communicated with the compressed air inlet at the rear end of the ignition spray gun. The purge branch pipe is provided with a purge valve and is communicated with the oil supply or Tianene air pipe between the fuel regulating valve and the atomizing branch pipe interface; the return branch pipe is provided with a return valve and a flow meter and is communicated with the return device, and the loosening branch pipe is provided with a loosening valve and a flow meter.

3. The vertical powder feed boiler system according to claim 1 is characterized in that: An auxiliary oil or air gun is also provided on the side wall of the lower part of the furnace, and the auxiliary oil or air gun is communicated with the ignition fuel pipe through a valve and a pipeline.

4. The vertical powder feed boiler system according to claim 3 is characterized in that: The steam main pipeline is provided with a plurality of drain pipes and drain valves, the high-pressure water supply pipe is provided with a water inlet valve, the buffer tank is provided with a liquid level gauge, the downstream end of the flue formed by the shell of the tertiary air preheater and the shell of the secondary air preheater are connected in series with a desulfurization tower, a bag dust collector and an induced draft fan in sequence, the outlet of the induced draft fan is connected with the chimney through a pipeline, the ignition tube is provided with an observation window, and the observation window is provided with high-temperature resistant glass, the primary fan, the secondary fan, the tertiary fan, the powder delivery fan and the induced draft fan are all driven by a variable frequency motor, and the air volume of each fan is controlled by adjusting the speed of the variable frequency motor, the primary air chamber is provided with a temperature sensor and a pressure sensor, the upper part or the top of the furnace is provided with a pressure sensor, an oxygen content sensor and a temperature sensor, the side walls of the preheating combustion chamber are provided with an upper temperature sensor, a middle temperature sensor and a lower temperature sensor, respectively, and a pressure gauge and a pressure sensor are provided at the outlet of the powder delivery fan, A camera tube is provided in the middle or upper part of the furnace, a fire detection camera is provided at the outer end of the camera tube, and a high-temperature resistant glass sealing plate is provided at the front end of the camera tube. A purge pipe pointing to the inner side of the high-temperature resistant glass sealing plate is also provided on the furnace wall on one side of the camera tube, and the purge pipe is connected to the equipped compressed air pipe through a purge valve.

5. The vertical powder feed boiler system according to claim 4 is characterized in that: A front electric damper is also provided on the flue upstream of the desulfurization tower, and a circulating flue gas pipe is provided on the flue upstream of the front electric damper. The circulating flue gas pipe is connected to the secondary air duct through a circulating flue gas fan, a circulating flue gas electric damper and a flow meter.

6. The vertical powder feed boiler system according to claim 4, characterized in that: It also includes a programmable controller, a memory and a touch screen. The memory and the touch screen are respectively connected to the programmable controller. All valves are electric valves. All electric valves and the variable frequency motors of all fans are connected to the control signal output end of the programmable controller. All temperature sensors, pressure sensors, flow meters, liquid level meters, oxygen content sensors and fire detection cameras are connected to the signal input end of the programmable controller.

7. The method for using the vertical powder feed boiler system according to claim 4 comprises the following steps:

1. Preparation before ignition ①. The buffer tank is filled with water and the ignition conditions are met. ②. Install the ignition spray gun in place and check the fire detection camera. ③. Open the sand adding valve and add quartz sand into the preheating combustion chamber through the sand adding hopper, so that the quartz sand naturally accumulates 50-70 cm high in the preheating combustion chamber. ④. Open the return valve and loosening valve, and make the return air velocity reach twice the loosening air velocity. ⑤. Start the primary fan, and use the introduction of primary air to make the quartz sand in the preheating combustion chamber reach a fluidized state. Turn on and adjust the induced draft fan to keep the pressure on the upper part or top of the furnace at 0-100Pa. ⑥. If this ignition is the first ignition of this vertical powder boiler system, start the powder delivery fan and adjust the speed of the powder delivery fan to 10% of its full load speed. If not, go directly to the next step. ⑦. Purge the furnace. Start the induced draft fan, secondary fan and tertiary fan. Make the secondary fan and tertiary fan rotate at 30% of their full load speed. Purge the furnace for 5-10 minutes. Adjust the speed of the secondary fan to 15% of its full load speed and the speed of the tertiary fan to 10% of its full load speed. ⑧. Adjust the speed of the primary fan to slowly increase to 40% of its full load speed to keep the quartz sand in the preheating combustion chamber in a fluidized state, and adjust the speed of the induced draft fan to keep the pressure in the furnace at 0-100Pa.

2. Oil ignition: (1). Open the purge valve and atomizing valve for 1 minute, then close the purge valve. After closing the purge valve, start the high-energy igniter, open the quick-cut valve and the fuel regulating valve at the same time. After 10 seconds, the high-energy igniter will be automatically cut off. At this time, the staff will observe through the observation window whether there is an open flame at the front end of the ignition spray gun. If not, it means that the ignition has failed. It is necessary to quickly close the quick-cut valve and the fuel regulating valve, open the purge valve, and purge. After 1 minute of purge, close the purge valve and repeat this step until an open flame appears at the front end of the ignition spray gun. Ignition is successful. (2) After successful ignition, maintain the fuel supply at 35-45t / h, increase the primary fan speed to 50-70% of its full load speed, and keep the primary air chamber temperature within 850℃; continue to heat up, and control the temperature increase rate of the preheating combustion chamber to below 400℃ / h.

3. Powder ignition: ①. If it is the first ignition, go directly to the next step. If it is not the first ignition, after the ignition is successful, start the powder delivery fan and slowly open it to 10%; ②. When the preheated combustion chamber temperature reaches 600±50℃, restart the furnace purge procedure: Start the induced draft fan, secondary fan and tertiary fan, adjust the frequency conversion motors driving the secondary fan and tertiary fan, make the corresponding fans rotate at 30% of their full load speed, purge the furnace for 5-10 minutes, adjust the speed of the secondary fan to 15% of its full load speed, adjust the speed of the tertiary fan to 10% of its full load speed, After the purge is completed, start the screw feeder or rotary valve and make the speed of the screw feeder or rotary valve reach 5% of its full load speed, adjust the speed of the powder feeding fan to 45% of its full load speed, adjust the speed of the primary fan to 65% of its full load speed, adjust the speed of the secondary fan to 15% of its full load speed, adjust the speed of the tertiary fan to 10% of its full load speed, and adjust the speed of the induced draft fan to 20% of its full load speed, and continue to burn and heat up. ③. When the temperature of the preheating combustion chamber rises to 700-800℃, and the temperature difference between any two of the temperature parameters sensed by the upper, middle and lower temperature sensors of the preheating combustion chamber does not exceed 50℃, and the operation is stable, close the quick-cut valve and fuel regulating valve, and stop using the ignition gun. ④. When the temperature sensor on the rear elbow senses a temperature of 550°C, the temperature sensor at the bottom of the furnace senses a temperature of 70-80°C, and the temperatures sensed by the upper, middle and lower temperature sensors of the preheating combustion chamber are all within the range of 850-900°C, the oil gun at the bottom of the furnace is put in. When the temperature measurement point at the bottom of the furnace reaches 300 degrees, try to put in combustible powder. When the highest temperature in the furnace reaches 900 degrees, stop the oil gun, put in combustible powder, gasify and run the system, and enter the furnace ignition stage. This can greatly shorten the ignition time and reduce the ignition cost. Specific steps: 1). By adjusting the speed of the secondary fan, tertiary fan and induced draft fan, the pressure at the top of the furnace is kept within the range of -90 to -110 Pa; 2) Start the fuel-boosting gun at the bottom of the furnace. When the temperature at the temperature measuring point at the bottom of the furnace reaches 300°C, try to add combustible powder. When the highest temperature in the furnace reaches 900°C, stop the fuel-boosting gun. 3). Adjust the speed of the powder delivery fan to 80% of its full load speed, observe whether the outlet pressure of the powder delivery fan reaches the design pressure, and observe the temperature rise of the preheating combustion chamber. If there is fire in the furnace within 60 seconds, the oxygen content decreases, and a small positive pressure appears, it can be judged that the combustible powder is ignited normally. If there is no fire within 60 seconds, the screw feeder or rotary valve and powder delivery fan should be stopped immediately, and the furnace should be purged. Start the induced draft fan, secondary fan and tertiary fan, adjust the variable frequency motors driving the secondary fan and tertiary fan, make the corresponding fans rotate at 30% of their full load speed, purge the furnace for 5-10 minutes, adjust the speed of the secondary fan to 15% of its full load speed, adjust the speed of the tertiary fan to 10% of its full load speed, and re-ignite the combustible powder after an interval of more than 10 minutes until the ignition is normal; 4. Powder ignition completes subsequent work: ①. After the combustible powder is ignited normally, the speed of the secondary fan should be immediately adjusted to 30-35% of its full load speed, and the speed of the tertiary fan should be adjusted to 20-25% of its full load speed, so that the oxygen content in the furnace is maintained within the range of 2-6%. According to the steam pressure rise of the main steam pipeline, the water level and steam temperature of the buffer tank should be controlled; ②. After the combustible powder is ignited normally, immediately contact the follow-up personnel to put the desulfurization tower and bag filter into use to ensure that the environmental protection parameters do not exceed the standard; ③. From the initial stage of ignition of combustible powder to the entire operation period, monitor the temperature of the preheating combustion chamber to ensure that the temperatures sensed by the upper, middle and lower temperature sensors on the preheating combustion chamber are maintained at 800-950℃. When the temperature is high, increase the amount of combustible powder appropriately; when the temperature is low, reduce the amount of combustible powder appropriately. At the same time, increase the air volume of the primary, secondary and tertiary air appropriately to ensure sufficient combustion of the combustible powder.

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