WO2016119670A1

WO2016119670A1 - Blend combustion method of fuel coal fly ash for biomass circulating fluidized bed boiler and device thereof

Info

Publication number: WO2016119670A1
Application number: PCT/CN2016/072082
Authority: WO
Inventors: 朱德辉; 张岩丰; 周大庆
Original assignee: 武汉凯迪工程技术研究总院有限公司
Priority date: 2015-01-30
Filing date: 2016-01-26
Publication date: 2016-08-04
Also published as: CN104832915A; CN104832915B

Abstract

A blend combustion method of fuel coal fly ash for a biomass circulating fluidized bed boiler (9) and a device thereof. In the method, the fuel coal fly ash is jetted onto the bottom of a dense phase combustion zone (13) bed layer inside the biomass circulating fluidized bed boiler (9) so that the fuel coal fly ash is mixed with incandescent biomass bed materials in a bubble state or a turbulent fluidized state to generate intensive heat and mass transfer and temperature increase with violent rolling and friction, thereby abrading away ash shells on the external layer of the fuel coal fly ash to expose unburned residual carbon black core therein, and finally the fuel coal fly ash is completely combusted in the dense phase combustion zone (13) and a dilute phase combustion zone (14). The device is mainly composed of a fuel coal fly ash storage bin (1), a rotary material feeding device (2), an ejector (3), an air blower (5), a transporting pipeline (6), a bottom feeding abrasion resistant spray nozzle (8) and so on, which are used with the biomass circulating fluidized bed boiler (9). By means of the device, the fuel coal fly ash can be recycled into the biomass circulating fluidized bed boiler (9) for fully combustion again to perform secondary power generation, thereby effectively reducing the amount of a biomass fuel, increasing the power generation capacity of unit fuel, and can reduce emission of coal combustion pollutant.

Description

Biomass circulating fluidized bed boiler mixed combustion coal fly ash method and equipment thereof

Technical field

The invention relates to a technology for recycling and energy saving and emission reduction of waste ash generated in a boiler combustion power generation process, in particular to a biomass circulating fluidized bed boiler mixed with a coal-fired fly ash method and a device thereof.

Background technique

With the increasing demand for energy in modern society, the construction of coal-fired boiler power plants is also increasing. Although China has a vast territory and a wide distribution of coal resources, there are many different types of coal, especially in the south and southwest regions of China. Many provinces have a large number of low-volatility coals such as anthracite and lean coal. When burning coal-fired boilers, these low-grade coals generally have problems such as high carbon content and unsatisfactory burnout of coal-fired fly ash, which not only wastes a lot of coal resources, but also brings a serious environment. Pollution. In order to solve the above problems, those skilled in the art also try to re-deliver unburned coal-fired fly ash particles to a coal-fired boiler for recycling, but these coal-fired fly ash particles are directly sent back to the coal by means of surface feeding. On the one hand, the outer part of the dilute phase combustion zone of the boiler is made of a gray shell layer which is not easy to conduct heat and burn, so that the internal flammable residual carbon core cannot reach the temperature required for combustion in the coal-fired boiler, and on the other hand, the gas The slip speed between the solid two phases is low, the heat transfer rate is small, the heating process is slow, and it flies out of the furnace of the coal-fired boiler when it has not yet reached a sufficient combustion temperature, that is, the coal-fired fly ash particles are only in The coal-fired boiler has gone through a game and has not been recycled and burned.

On the other hand, with the declining traditional fossil energy reserves such as coal, biomass fuel has developed rapidly as a renewable alternative energy source. The total installed capacity of power plants using biomass fuel direct-fired power generation is also increasing. However, due to the radius and total amount of biomass fuel resource acquisition, many biomass boiler power plants have reduced the design production load due to the lack of acquisition of biomass fuel, especially when the power plant adopts various biomass fuels. In the case of a biomass circulating fluidized bed boiler with high efficiency and sufficient combustion and low residue ash and good environmental performance, the amount of biomass fuel required to sustain power generation is extremely large, and even if the amount of acquisition cannot be ensured, it can only be discontinued. How to effectively expand the source of raw materials for biomass boiler power plants and ensure their production scale and power generation efficiency has been recognized as a difficult problem and a direction for efforts by those skilled in the art, but so far no satisfactory technical solutions have been introduced.

Summary of the invention

The object of the present invention is to provide a biomass circulating fluidized bed boiler mixed with coal-fired fly ash and a device thereof, which can ensure that the coal-fired fly ash produced by the coal-fired boiler is again in the biomass circulating fluidized bed boiler Fully burned for secondary power generation; at the same time, it can effectively reduce the use of biomass fuel, reduce fuel input costs, increase power generation hours, and reduce pollutant emissions.

In order to achieve the above object, the biomass circulating fluidized bed boiler designed by the invention is mixed with the coal-fired fly ash method, which is to re-deliver the fly ash discharged from the coal-fired boiler to the biomass circulating fluidized bed boiler for recycling. The process is unique in that it includes the following steps:

1) the coal-fired fly ash particles are in a suspended flow state by airflow, and are sprayed into the bottom of the dense phase combustion zone bed above the air distribution plate in the biomass circulating fluidized bed boiler;

2) mixing the coal-fired fly ash particles with a large amount of hot biomass bed particles in a bubbling fluidized state or a turbulent fluidized state in a dense phase combustion zone to produce intense heat and mass transfer and temperature rise, and occur together intensely Rolling and rubbing, grinding off the gray shell of the outer layer of coal-fired fly ash particles, revealing the unburned black core of the carbon residue;

3) Using the high oxygen concentration of the primary air output from the hood on the air distribution plate, the residual carbon black core and the oxygen in the dense phase combustion zone are rapidly and fully combusted, and most of the carbon black remains. The core is burned out;

4) The remaining residual carbon black core enters the relatively low temperature dilute phase combustion zone above the dense phase combustion zone under the action of fluidizing wind in the biomass circulating fluidized bed boiler, and continues to burn under the inertia of high temperature and high heat. The reaction finally burns out the remaining black core of the residual carbon, thereby realizing the secondary combustion power generation of the coal-fired fly ash particles.

Preferably, in the step 1), the blending amount of the coal-fired fly ash particles and the mass percentage of the biomass fuel in the biomass circulating fluidized bed boiler are controlled at 10 to 30% of the coal-fired fly ash particles, The material fuel is 70-90%; among them, the best mass percentage is controlled by: 15-20% of coal-fired fly ash particles and 80-85% of biomass fuel. Biomass circulating fluidized bed boilers are characterized by high efficiency of combustion and low content of fly ash residues (the amount of fly ash produced according to the type of biomass fuel is generally in the range of 3 to 5%, and the special case does not exceed 10%) Therefore, the addition of 30% or less of coal-fired fly ash particles will not cause a burden on the biomass circulating fluidized bed boiler, and the circulation amount is moderate. The fluidized environment of the biomass circulating fluidized bed boiler can be fully utilized to fly the coal. The ash particles are burned out.

Preferably, in the step 1), the flow rate of the suspended mixture of the coal fly ash particles and the air is controlled to be 12 to 18 m/s. Among them, the optimum flow rate is controlled at 14 to 16 m/s, for example, 15 m/s. Appropriate flow rate ensures that coal-fired fly ash particles are injected into the bottom of the dense phase combustion zone at a certain pressure to increase the disturbance, contact and mixing with the hot biomass bed particles, creating conditions for subsequent intense combustion reactions. .

Preferably, in the step 1), the mass ratio of the coal-fired fly ash particles to the air is controlled to be 2.0 to 3.5:1. Among them, the optimum mass ratio is controlled at 2.5 to 3.0:1. The proper mass ratio can ensure the concentration of coal-fired fly ash particles into the bottom of the dense phase combustion zone, and can simultaneously supplement the oxygen through pneumatic conveying, so as to cooperate with the oxygen delivered by the primary air to make most of the coal-fired fly ash particles. The charcoal in the burning is exhausted.

Preferably, in the step 1), the residual carbon content in the coal fly ash particles is 8-15% of the total weight. Among them, most of the coal-fired fly ash particles have a residual carbon content of 10 to 14% of the total weight. In general, the calorific value of the coal-fired fly ash particles has a calorific value of about 800 to 1200 kcal/kg, which can effectively supplement the low heat value of the biomass fuel power generation, and burns in the dense phase by burning coal fly ash particles. The two-stage combustion of the zone and the dilute phase combustion zone is used to further improve the power generation efficiency of the biomass circulating fluidized bed boiler.

Preferably, in the step 2) and the step 3), the reaction residence time of the coal-fired fly ash particles in the dense phase combustion zone is controlled to be 0.8 to 1.5 s. Among them, the best reaction residence time is controlled at 1.0 to 1.2 s. Appropriately prolonging the reaction residence time of coal-fired fly ash particles in the dense phase combustion zone can promote the full contact and mixed combustion with the oxygen in the primary air to ensure that the coal-fired fly ash particles are burned as much as possible at this stage.

Preferably, in the step 4), the reaction residence time of the remaining carbon black core remaining in the coal-fired fly ash particles in the dilute phase combustion zone is controlled to be 5.2 to 6.5 s. Among them, the optimal reaction residence time is controlled at 5.5 to 6.0 s. In this way, the total residence time of the coal-fired fly ash particles in the biomass circulating fluidized bed boiler can be effectively extended to ensure that all of the coal-fired fly ash particles are completely burned out at this stage.

The invention relates to a biomass circulating fluidized bed boiler specially designed for realizing the above method, which comprises a coal-fired fly ash equipment, comprising a coal-fired fly ash storage bin used in combination with a biomass circulating fluidized bed boiler, the special features of which are:

The bottom discharge port of the coal-fired fly ash storage bin is connected to the powder input end of the injector through a rotary feeding device, and the air input end of the injector is connected to the blower through a check valve, the suspension of the injector The material nozzle is connected to one end of the transmission pipeline, and the other end of the transmission pipeline enters from the bottom air chamber of the biomass circulating fluidized bed boiler, and is connected to the bottom feed wear-resistant nozzle through the air distribution plate uniformly distributed with the wind hood. The bottom feed wear nozzle is located in the dense phase combustion zone above the air distribution plate.

Preferably, the position of the injection port of the bottom feed wear nozzle is higher than the position of the air outlet of the hood on the air distribution plate by 500 to 800 mm. In this way, the primary air with a high oxygen concentration ejected from the hood directly acts on the coal-fired fly ash particles sprayed from the bottom-feeding wear-resistant nozzle above it, on the one hand, the coal-fired fly ash particles can be promoted in the dense phase combustion zone. Produce violent tumbling and friction, remove the gray shell and expose the black core of the carbon residue; on the other hand, ensure the black core and oxygen of the carbon residue Fully in contact with the mixture, a violent combustion reaction occurs, and most of the carbon black core is burned out.

Further, a preferred angle between the injection direction of the bottom feed wear-resistant nozzle and the horizontal plane is 0 to 25°. In this way, the coal-fired fly ash particles are sprayed at a nearly horizontal angle, which can enhance the disturbance between the coal-fired fly ash particles and the particles of the hot biomass bed material, and increase the contact area with the oxygen in the primary air, thereby improving the coal-fired fly ash particles. The burning rate of the residual carbon black core.

Further, the number of the bottom-feeding wear-resistant nozzles is 2-6, which may be 2, 4 or 6, evenly arranged above the air distribution plate, and each bottom-feeding wear-resistant nozzle passes through the branch pipe and the transmission pipe. The other end is connected. In this way, the coal-fired fly ash particles entering the bottom of the dense phase combustion zone in the biomass circulating fluidized bed boiler can be evenly distributed to ensure stable, efficient and reliable operation of the biomass circulating fluidized bed boiler.

Further, the transmission pipe includes a horizontal pipe section and a vertical pipe section, and the horizontal pipe section and the vertical pipe section are connected by a wear-resistant elbow. In this way, it is possible to ensure the wear resistance of the transmission pipe subjected to the most severe bending portion, prolong the service life of the entire transmission pipe, and ensure that the coal-fired fly ash particles can be quickly and smoothly turned to the bottom of the biomass circulating fluidized bed boiler.

Further, the blower is a Roots blower, and two sets are arranged in parallel, and one set of Roots blower is provided with a venting valve. The Roots blower is a positive displacement fan that uses two leaf-shaped rotors to move relative to each other in the cylinder to compress and deliver gas. It is well suited for low-pressure air transport of coal-fired fly ash particles. One or two sets of Roots blowers can be turned on according to actual needs, and the amount of air supply can be adjusted by the venting valve to meet the needs of pneumatic conveying of various coal ash particles.

Still further, the rotary dosing device is a rotary feed valve remotely controlled by the frequency converter. Rotary feed valve can be widely used in the transportation of powder, granular materials and powder mixture. It can remotely adjust and control the speed through the frequency converter, especially suitable for the quantitative transportation of coal fly ash particles, so as to meet the circulation of biomass. Accurate control of the percentage content of coal-fired fly ash particles in a chemical bed boiler.

The invention carefully studies and analyzes the low ash content of the biomass fuel combustion power generation, the small pollutant discharge, and the high carbon residue and the environmental pollution caused by the coal-fired fly ash particles discharged from the coal-fired boiler, combined with the biomass. The operating characteristics of the circulating fluidized bed boiler subtly inject the coal-fired fly ash particles into the bottom of the dense phase combustion zone bed in the biomass circulating fluidized bed boiler. The advantages are mainly reflected in the following aspects:

First, the coal-fired fly ash particles enter the bottom of the dense phase combustion zone bed, which can be fully squeezed into contact with a large number of hot biomass bed material particles, carry out strong heat and mass transfer, rapidly heat up and start to burn, effectively overcome The problem of the combustion temperature cannot be reached by feeding the coal-fired fly ash particles into the furnace by means of surface feeding. At the same time, the dense phase combustion zone is not burned out. After a small amount of residual carbon black core enters the relatively low temperature dilute phase combustion zone, it can still maintain high temperature and high heat state under the action of inertia, which is beneficial to continue burning.

Second, the dense phase combustion zone of the biomass circulating fluidized bed boiler is usually in the state of a bubbling fluidized bed or a turbulent fluidized bed, and a large amount of hot biomass bed material particles can be combined with the coal fly ash particles injected therein. Producing severe tumbling and friction, the ash shell of the outer layer of the coal-fired fly ash particles can be worn away in an instant, so that the exposed internal carbon black core is in full contact with the oxygen in the primary air, thereby greatly improving the efficiency of the combustion reaction.

Third, after the coal-fired fly ash particles are sprayed into the bottom of the dense phase combustion zone bed, the residence time of the bed in the dense phase combustion zone can be effectively increased under the hindrance and envelopment of a large amount of hot biomass bed material particles, thereby Extend the total residence time in the biomass circulating fluidized bed boiler to ensure that the coal-fired fly ash particles are completely burned out.

Fourth, the coal-fired fly ash particles are sprayed into the bottom of the bed of the dense phase combustion zone, just above the primary air blown by the hood on the air distribution plate. At this time, the oxygen concentration in the primary air is relatively high, which is convenient for coal-fired fly ash. A sufficiently vigorous combustion reaction of the particles is very advantageous for increasing the burning rate of the black core of the carbon residue.

Fifthly, the full recovery and utilization of coal-fired fly ash particles in biomass circulating fluidized bed boilers effectively solves the fatal defect of high carbon content and low burnup of fly ash in coal-fired boiler power plants, which fully utilizes combustion. Coal fly ash particles for secondary power generation, and correspondingly reduce the amount of biomass fuel, but also achieve energy-saving emission reduction, increase the number of hours of power generation per unit of raw materials, resulting in a multi-faceted beneficial effect.

Sixth, the use of biomass circulating fluidized bed boilers to blend coal-fired fly ash particles does not require major modifications to the original biomass circulating fluidized bed boiler, only adding storage bins, injectors, blowers and corresponding piping The system can be used, the amount of reconstruction works is small, the construction is convenient, and it is easy to promote and apply.

DRAWINGS

1 is a schematic view showing the structure of a biomass circulating fluidized bed mixed with coal-fired fly ash equipment.

FIG. 2 is a partially enlarged schematic structural view of the air distribution plate of FIG. 1. FIG.

In the figure: coal-fired fly ash storage bin 1, rotary feeding device 2, ejector 3, check valve 4, blower 5, conveying pipe 6, wear-resistant elbow 7, bottom feeding wear-resistant nozzle 8, biomass circulation The chemical bed boiler 9, the bottom plenum 10, the air distribution plate 11, the hood 12, the dense phase combustion zone 13, the dilute phase combustion zone 14, and the vent valve 15.

detailed description

The apparatus and process of the present invention are further described in detail below with reference to the accompanying drawings and specific embodiments.

The biomass circulating fluidized bed boiler shown in the figure is mixed with a coal-fired fly ash plant, and has a coal-fired fly ash storage bin 1 for use with the biomass circulating fluidized bed boiler 9. The bottom discharge port of the coal-fired fly ash storage bin 1 is connected to the powder input end of the injector 3 through the rotary feeding device 2, and the rotary feeding device 2 uses a rotary feed valve remotely controlled by the frequency converter to precisely control the coal burning. The amount of fly ash delivered. The air input end of the ejector 3 is connected to the blower 5 through the check valve 4, the blower 5 is a Roots blower, and the Roots blower is arranged in parallel with two sets, wherein a set of Roots blower is provided with a venting valve 15 which can be partially required Or all of the Roots blower is turned on, and the amount of air supplied by the vent valve is adjusted to obtain the required air volume. The suspension nozzle of the ejector 3 is connected to one end of the transmission pipe 6, and the transmission pipe 6 is composed of a horizontal pipe section and a vertical pipe section, and the horizontal pipe section and the vertical pipe section are connected by a wear-resistant elbow 7 to enhance the most severe impact. The wear resistance of the bent portion improves the working life of the entire transfer pipe 6, and the other end of the transfer pipe 6 enters from the bottom plenum 10 of the biomass circulating fluidized bed boiler 9 and passes through the cloth uniformly distributed with the hood 12. The plate 11 is connected to the bottom feed wear nozzle 8 which is located in the dense phase combustion zone 13 above the air distribution plate 11.

In this embodiment, the position of the injection port of the bottom feed wear-resistant nozzle 8 is higher than the position of the air outlet of the wind cap 12 on the air distribution plate 11 by 650 mm, so as to facilitate the full contact and mixing of the coal-fired fly ash particles with the primary air, and the bottom feed wear-resistant The angle between the injection direction of the nozzle 8 and the horizontal plane is 0 to 10° to further increase the contact disturbance between the coal-fired fly ash particles and the primary air. At the same time, the bottom feeding wear-resistant nozzles 8 are preferably arranged in pairs, and the number may be two, four or six. In this embodiment, four bottom-feeding wear-resistant nozzles 8 are used, which are evenly arranged above the air-distributing plate 11, each The bottom feed wear-resistant nozzles 8 are all connected to the other end of the transfer pipe 6 through the branch pipe, so that the coal-fired fly ash particles output from the ejector 3 can be uniformly injected into the dense phase combustion zone in the biomass circulating fluidized bed boiler 9. 13 bed bottom.

The process of the above-mentioned biomass circulating fluidized bed boiler mixed with coal-fired fly ash equipment in actual operation is summarized as follows:

1) It is preliminarily preferred that the coal-fired fly ash particles discharged from the coal-fired boiler having a residual carbon content of 10 to 14% of the total weight are loaded into the coal-fired fly ash storage bin 1. When it is needed, the rotary feeding device 2 is turned on, and the rotating feed rate is controlled by the frequency converter, so that the coal-fired fly ash particles in the coal-fired fly ash storage bin 1 are delivered to the injector 3 according to the set feed amount. At the same time, the blower 5 is turned on to deliver air to the ejector 3, the check valve 4 is used to prevent air and coal fly ash particles from flowing back to the blower 5, and the vent valve 15 is used to adjust the air flow output from the blower 5 through the above device The synergistic effect is that the coal-fired fly ash particles injected from the injector 3 to one end of the transmission pipe 6 are in a floating flow state, wherein the mass ratio of the coal-fired fly ash particles to the air is preferably controlled within a range of 2.5 to 3.0:1. . Subsequently, the suspended mixture of coal-fired fly ash particles and air passes through the transfer pipe 6 at a flow rate of 14 to 16 m/s, and is sprayed by the bottom feed wear-resistant nozzle 8 at the other end of the transfer pipe 6. The mixture is incorporated into the bottom of the dense phase combustion zone 13 above the air distribution plate 11 in the biomass circulating fluidized bed boiler 9 at an angle of 0 to 10° from the horizontal plane. Among them, the blending amount of coal-fired fly ash particles and the mass percentage of biomass fuel in the biomass circulating fluidized bed boiler 9 are preferably controlled to be 15-20% of coal-fired fly ash particles and 80-85% of biomass fuel.

2) In the dense phase combustion zone 13 described above, since the wind speed of the circulating fluidized bed is low, the coal-fired fly ash particles can stay therein for a sufficient period of time, and a large amount in the bubbling fluidization state or the turbulent fluidization state. The hot biomass bed material particles are intertwined and mixed to produce strong heat and mass transfer and temperature rise, and violent tumbling and friction occur together. The outer shell of the coal-fired fly ash particles is not easily burned, and the unburned residue is removed. The carbon black core is exposed.

3) Subsequently, the black carbon core exposed in the dense phase combustion zone 13 is in full contact with the primary air output from the hood 12 on the air distribution plate 11, and a rapid and intense combustion reaction occurs, and most of the carbon residue is removed. The black core burned out. In order to ensure the burn-out effect of the dense phase combustion zone 13, the reaction residence time of the coal-fired fly ash particles in the dense phase combustion zone 13 is preferably controlled to be 1.0 to 1.2 s.

4) Finally, the remaining carbon black core enters the relatively low temperature dilute phase combustion zone 14 in the dense phase combustion zone 13 under the action of fluidizing wind in the biomass circulating fluidized bed boiler 9, and the inertia of high temperature and high heat Continue to maintain the combustion reaction. Similarly, in order to ensure the burn-out effect of the dilute phase combustion zone 14, the reaction residence time of the residual carbon black core remaining in the coal-fired fly ash particles in the dilute phase combustion zone 14 is preferably controlled at 5.5 to 6.0 s until the remaining residue The carbon black core is completely burned, thereby achieving secondary combustion power generation of coal-fired fly ash particles.

The coal-fired fly ash particles discharged from the coal-fired boiler are recycled by the method and the device of the invention, and the doped coal-fired fly ash particles can reach 30% of the total fuel amount. According to the coal-fired fly ash particles 30%, the biomass fuel 70% by mass, the biomass power plant annual operation 7000 hours calculation: a 30MW biomass circulating fluidized bed boiler mixed with coal-fired fly ash particles can be It reached 71,400 tons, and the amount of biomass fuel matched with it was 176,000 tons. The calculation shows that the coal-fired power plant of a 300-600MW unit (including circulating fluidized bed boiler and pulverized coal boiler power plant) has far more than 71,400 tons of coal, which can fully meet the biomass circulation of a 30MW unit. The need for fluidized bed boilers for secondary generation of coal-fired fly ash. Therefore, the biomass circulating fluidized bed boiler designed according to the present invention is blended with the coal-fired fly ash method to reform the biomass power plant, and the fly ash of the coal-fired power plant can be recovered in combination with the treatment, thereby not only saving a large amount of biomass fuel, but also Greatly reduce the hazards of coal-fired fly ash and achieve a win-win situation for power generation and environmental protection.

Claims

A biomass circulating fluidized bed boiler mixed with coal-fired fly ash method, which is a process for re-conveying fly ash discharged from a coal-fired boiler into a biomass circulating fluidized bed boiler (9) for recycling : The method includes the following steps:

1) the coal-fired fly ash particles are in a suspended flow state by gas flow, and are sprayed into the bottom of the dense phase combustion zone (13) above the air distribution plate (11) in the biomass circulating fluidized bed boiler (9);

2) mixing the coal-fired fly ash particles with a large amount of hot biomass bed material particles in a bubbling fluidization state or a turbulent fluidization state in the dense phase combustion zone (13) to produce strong heat and mass transfer and temperature rise, and Severe tumbling and friction occurred together, grinding off the gray shell of the outer layer of coal-fired fly ash particles, revealing the unburned black core of the carbon residue;

3) Using the high concentration of oxygen in the primary air output from the hood (12) on the air distribution plate (11), the residual carbon black core and oxygen in the dense phase combustion zone (13) are rapidly and fully burned. Reaction, in which most of the carbon black core is burned out;

4) The remaining residual carbon black core enters the relatively low temperature dilute phase combustion zone (14) above the dense phase combustion zone (13) under the action of fluidizing wind in the biomass circulating fluidized bed boiler (9). Under the inertia of high temperature and high heat, the combustion reaction is continued, and finally the remaining black core of the residual carbon is burned out, thereby realizing the secondary combustion power generation of the coal fly ash particles.
The method for blending a coal-fired fly ash in a biomass circulating fluidized bed boiler according to claim 1, wherein in the step 1), the amount of coal fly ash particles is mixed with the biomass circulating fluidized bed The mass percentage of biomass fuel in the boiler (9) is controlled at 10 to 30% of the coal-fired fly ash particles and 70 to 90% of the biomass bed fuel.
The method for blending a coal-fired fly ash in a biomass circulating fluidized bed boiler according to claim 1, wherein in the step 1), the amount of coal fly ash particles is mixed with the biomass circulating fluidized bed The mass percentage of biomass fuel in boiler (9) is controlled at 15-20% for coal-fired fly ash particles and 80-85% for biomass fuel.
The method for blending a coal-fired fly ash in a biomass circulating fluidized bed boiler according to claim 1, characterized in that In the step 1), the flow rate of the suspended mixture of the coal fly ash particles and the air is controlled to be 12 to 18 m/s.
The method for blending a coal-fired fly ash in a biomass circulating fluidized bed boiler according to claim 1, wherein in the step 1), the flow rate of the suspended mixture of the coal fly ash particles and the air is controlled at 14 to 16m/s.
The method for blending a coal-fired fly ash in a biomass circulating fluidized bed boiler according to claim 1, wherein in the step 1), the mass ratio of the coal-fired fly ash particles to the air is controlled to be 2.0 to 3.5: 1.
The method for blending a coal-fired fly ash in a biomass circulating fluidized bed boiler according to claim 1, wherein in the step 1), the mass ratio of the coal-fired fly ash particles to the air is controlled at 2.5 to 3.0: 1.
The method for blending a coal-fired fly ash in a biomass circulating fluidized bed boiler according to claim 1, wherein in the step 1), the residual carbon content of the coal-fired fly ash particles accounts for 8 of the total weight thereof. ~15%.
The method for blending a coal-fired fly ash in a biomass circulating fluidized bed boiler according to claim 1, wherein in the step 1), the residual carbon content of the coal-fired fly ash particles accounts for 10% of the total weight thereof. ~14%.
The method for blending a coal-fired fly ash in a biomass circulating fluidized bed boiler according to claim 1, wherein in the step 2) and the step 3), the coal-fired fly ash particles are in a dense phase combustion zone (13) The reaction residence time is controlled at 0.8 to 1.5 s.
The method for blending a coal-fired fly ash in a biomass circulating fluidized bed boiler according to claim 1, wherein in the step 2) and the step 3), the coal-fired fly ash particles are in a dense phase combustion zone (13) The reaction residence time is controlled from 1.0 to 1.2 s.
The method for blending a coal-fired fly ash in a biomass circulating fluidized bed boiler according to claim 1, wherein The problem is as follows: in the step 4), the reaction residence time of the residual carbon black core remaining in the coal-fired fly ash particles in the dilute phase combustion zone (14) is controlled to be 5.2 to 6.5 s.
The method for blending a coal-fired fly ash in a biomass circulating fluidized bed boiler according to claim 1, wherein in the step 4), the residual black core of the residual coal in the fly ash particles is burned in a dilute phase The reaction residence time of zone (14) is controlled between 5.5 and 6.0 s.
A biomass circulating fluidized bed boiler specially designed for the implementation of the method of claim 1 comprises a coal-fired fly ash storage device, comprising a coal-fired fly ash storage tank for use with a biomass circulating fluidized bed boiler (9) (1), which is characterized by:

The bottom discharge port of the coal fly ash storage bin (1) is connected to the powder input end of the ejector (3) through a rotary feeding device (2), and the air input end of the ejector (3) passes through The return valve (4) is connected to the blower (5), the suspension nozzle of the injector (3) is connected to one end of the transmission pipe (6), and the other end of the transmission pipe (6) is from the biomass circulating fluidized bed. The bottom plenum (10) of the boiler (9) enters and is connected to the bottom feed wear nozzle (8) through a ventilating plate (11) uniformly distributed with a hood (12), the bottom feed wear-resistant nozzle ( 8) Located in the dense phase combustion zone (13) above the air distribution plate (11).
The biomass circulating fluidized bed boiler-fired coal-fired fly ash apparatus according to claim 14, wherein the bottom feed wear nozzle (8) has a higher injection port position than the air distribution plate (11) The position of the air outlet of the upper hood (12) is 500 to 800 mm.
The apparatus for blending a coal-fired fly ash in a biomass circulating fluidized bed boiler according to claim 14 or 15, wherein the angle between the injection direction of the bottom feed wear-resistant nozzle (8) and the horizontal plane is 0-25 °.
The biomass circulating fluidized bed boiler-fired coal-fired fly ash apparatus according to claim 14 or 15, wherein the number of the bottom-feeding wear-resistant nozzles (8) is 2-6, uniformly arranged in the same Above the air distribution plate (11), each bottom feed wear-resistant nozzle (8) is connected to the other end of the transmission pipe (6) through a branch pipe.
The biomass circulating fluidized bed boiler-fired coal-fired fly ash apparatus according to claim 14 or 15, wherein the transmission pipe (6) comprises a horizontal pipe section and a vertical pipe section, and the horizontal pipe section and the vertical pipe section are Interconnected by wear-resistant elbows (7).
The biomass circulating fluidized bed boiler-fired coal-fired fly ash plant according to claim 14 or 15, wherein the blower (5) is a Roots blower, and two sets are arranged in parallel, one set of Roots A vent valve (15) is provided on the fan.
The biomass circulating fluidized bed boiler-fired coal-fired fly ash apparatus according to claim 14 or 15, wherein the rotary feeding device (2) is a rotary feed valve remotely controlled by the frequency converter.