CN114790398A

CN114790398A - Multi-fuel upgrading separation and coal-fired power plant boiler coupling process system

Info

Publication number: CN114790398A
Application number: CN202210479010.2A
Authority: CN
Inventors: 李波
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-05-05
Filing date: 2022-05-05
Publication date: 2022-07-26

Abstract

The invention relates to a coupling process system of multi-fuel upgrading separation and a coal-fired power station boiler, which comprises a boiler body, an air and smoke system, a pulverizing system, a combustion system and a pyrolysis system. The method is characterized in that the fuel is multi-component fuel, the multi-component fuel is pyrolyzed in a pyrolysis furnace, and pyrolysis products are semicoke, tar, hydrogen-rich synthetic gas and water; the qualified semicoke is not passed through a powder making system, and is fed into a hearth for combustion by adopting a hot air powder feeding process of an intermediate storage bin, hydrogen-rich synthetic gas is fed into the hearth for combustion, and the pyrolysis system can partially or completely replace the original powder making system; the recycled water enters a water treatment system of the coal-fired power station for utilization, and tar is sold to the outside; and the pyrolysis exhaust gas is treated by the air-smoke system and then discharged into the atmosphere. The invention realizes the cooperative disposal of coal, biomass, solid waste, industrial solid waste, hazardous waste and the like; the reasonable utilization of semicoke, hydrogen-rich synthesis gas and tar in multi-component fuel by classification and quality separation is realized; the recycling of water in the multi-component fuel is realized; the invention reduces the power generation cost, improves the power generation efficiency, increases the income of a power plant, improves the flexibility peak regulation capability, reduces the emission of carbon dioxide, and accords with the sustainable development strategy of the nation and the coal-fired power generation industry.

Description

Multi-fuel upgrading separation and coal-fired power plant boiler coupling process system

Technical Field

The invention belongs to the field of coal-fired power generation, and particularly relates to a coupling process system for upgrading and separating a multi-fuel and a coal-fired power station boiler.

Background

The coal-fired power generation industry develops at a high speed for many years, and the productivity of the coal-fired power generation industry tends to be saturated; the coal-fired cost is increased year by year, and the proportion of the coal-fired cost to the coal-fired power generation cost is higher and higher; environmental protection pressure brought by national policies such as ultra-low emission is continuously increased; the nation requires flexible modification of a coal-fired power generating unit, and the peak shaving capacity of the unit is improved; the simple technical development of the coal-fired generator set also faces the bottleneck period, and the existing coal-fired generator setThe potential for technical modification of motor trains has been exploited. The coal-fired power generation industry urgently needs a comprehensive technology, the existing resources and technologies are fully utilized, the integrated comprehensive application of coal, chemical, electricity and waste is realized, the pressure of the coal-fired power generation industry is relieved on the basis of realizing energy conservation and emission reduction, the operation field of a coal-fired power plant is expanded, and the overall benefit of the coal-fired power generation industry is improved. Renewable energy is coupled with coal for power generation, so that integrated comprehensive application of coal, chemical, electricity and waste is realized, the fuel source is expanded, and the fuel cost of a coal-electricity unit is reduced; the unit power generation coal consumption is reduced, and the unit power generation cost is reduced; the power grid deep peak regulation requirement is met; reduction of CO ₂ The emission is the key of high-quality development in the field of future thermal power.

The coal-electricity low-carbon development is actually to greatly reduce the coal burning amount on the premise of not reducing the generated energy. To achieve this goal, there are mainly 3 approaches, namely coal-electricity upgrade upgrading, CCUS (carbon capture, utilization and sequestration), and renewable energy coupling. The coal power increasing effect is a work which is vigorously developed in the past and at present, the national power supply coal consumption rate is reduced to 303.7g/kWh by 11 months in 2021, and the power supply coal consumption of the most advanced domestic unit is about 260-280 g/kWh, so that the carbon reduction space is about 10% through the coal power increasing effect, and the current carbon reduction target cannot be met. The CCUS may be a future technology for realizing low-carbon coal power under the condition of not reducing the coal burning quantity, but research and development and demonstration of the CCUS technology need to solve a plurality of problems of high cost, high energy consumption, utilization, sealing and the like, and the innovation development of the CCUS is believed to be accelerated inevitably under the promotion of '3060', but large-scale popularization and application cannot be realized within 10 years. Especially considering the huge amount of coal electric units in China, for CO exceeding 50 hundred million t/a ₂ The emission amount is difficult to achieve the zero-carbon emission target by the CCUS technology alone. Therefore, the high-efficiency coal-electricity + renewable energy coupling is the main direction of the current low-carbon development of coal-electricity.

Coal is a solid combustible mineral formed gradually by ancient plants buried underground and undergoing complex biochemical and physicochemical changes. Chinese coal classification, which is to classify all coals into lignite, bituminous coal and anthracite according to the volatile content of the coals; dry ashless based volatiles (V) _daf )＜10% is anthracite; dry ashless based volatiles (V) _daf ) More than 10 percent of bituminous coal, the total volatile components of the bituminous coal are 10 to 20 percent, 20 to 28 percent, 28 to 37 percent and>the 37 percent of four stages are divided into low, medium and high volatile bituminous coals; dry ashless based volatiles (V) _daf ) Lignite is more than 37%.

The total moisture of the coal used for the power station boiler in China is approximately Mar =2% -44%, and generally, about 2500kJ of heat is needed for evaporating 1kg of moisture in the coal, which is equivalent to the low-grade calorific value of 0.085kg of standard coal. If the average water content of 23 percent is calculated, each ton of power generation fire coal is dried to the total water content of 8 percent allowed by a generating set, 375MJ of energy is consumed, the lower calorific value is equivalent to 0.013t of standard coal, and 104-degree electricity can be generated. While one ton of coal can generate 3300 deg.C electricity. When high-moisture raw coal is combusted in a hearth, moisture in the coal absorbs heat and evaporates, a large amount of latent heat of gasification is discharged from a chimney in white, and according to experimental calculation, the energy consumed by vaporization in the combustion process is up to 20%. The moisture in the raw coal increases the water vapor content and the smoke loss of the flue gas, and the boiler efficiency is greatly reduced. The increase of the water vapor content in the flue gas can increase the partial pressure of the water in the flue gas and reduce the dew point of the flue gas, thereby causing the dust deposition and the corrosion of low-temperature heating surfaces such as an economizer and the like to be aggravated. Meanwhile, the increase of the smoke amount can also cause the power consumption of the induced draft fan to increase. Too much raw coal moisture enables the air quantity requirement of powder making and drying to be correspondingly increased, so that the pipeline is abraded, the power consumption of the powder exhauster is further increased, and the caking blockage in a coal bunker, a coal feeder and a coal dropping pipe can be caused. The high moisture of the raw coal also causes the coal dust to fly in the furnace without smoothness, slow ignition, incomplete combustion and the like. In short, the influence of the high-moisture raw coal on the unit finally causes the reduction of the thermal efficiency, and the economic loss is serious. The total moisture content of the coal of the power plant is controlled within 6-8 percent, and the maximum moisture content is not more than 10 percent.

In coal classification, some coals such as brown coal and long flame coal, which have high moisture, low density, high volatile content, no caking, strong chemical reactivity, poor thermal stability and low calorific value, are collectively called low-rank coals. Brown coal, also known as firewood coal, is mostly brown or brownish black and is a high volatile matter (V) _daf More than 50 percent of high moisture content (25 to 60 percent),The low-quality fuel has high ash content (about 30 percent), low calorific value (about 3200 kcal/kg), low ash melting point, easy weathering and cracking, easy oxidation and spontaneous combustion, and is the mineral coal with the lowest coalification degree.

The lignite is directly used for power generation, the boiler smoke discharge loss is large compared with low-moisture coal, the direct combustion thermal efficiency of the boiler is low, the economical efficiency is limited, and CO is generated ₂ The discharge amount of (a) is also large. The water content of the lignite is high, generally 25% -60%, when water in the high-moisture lignite is combusted, a large amount of water vapor is generated in a hearth, so that on one hand, the temperature of the hearth is reduced, the coal combustion amount of the hearth is increased, on the other hand, the heating surface of the boiler is increased, the boiler body, the coal pulverizing system and the smoke and air pulverized coal pipeline are large, and the heat loss of exhaust smoke is increased.

The areas such as inner Mongolia with concentrated lignite resources are typical areas rich in coal and water in China. A large amount of pithead power plants collect underground water as the water supplement of the power plants, so that underground water resources are exhausted, the grasslands are desertified in a large area, and vicious circle is formed in a long time. At present, aiming at the problems, a common method at home and abroad is to dry lignite to a certain moisture by adopting a lignite predrying technology and then enter a boiler for combustion. The existing power station lignite drying and pulverizing system focuses on drying and pulverizing lignite, and upgrading of lignite brings a lot of problems of storage, packaging, transportation, spontaneous combustion, environmental pollution and the like of upgraded lignite, and cannot be comprehensively considered with the lignite pulverizing system of a power plant, so that various lignite upgrading technologies cannot be popularized and applied.

Coal mills are machines that break up coal briquettes and grind them into coal fines, and are important auxiliary equipment for coal powder furnaces. The coal mill is an important component of a coal milling system of a coal-fired power plant, and the power consumption of the coal mill equipment accounts for about 30% of the service power. The coal mills are of many types and can be classified into three types, i.e., low-speed coal mills, medium-speed coal mills and high-speed coal mills, depending on the rotational speed of the coal grinding operation member. The low-speed coal mill is mainly a drum-type steel ball mill, generally called steel ball mill or ball mill for short. The steel ball mill is heavy and bulky, high in power consumption and large in noise; but has wide application range to coal types and reliable operation, and is particularly suitable for grinding hard anthracite. The currently domestic medium-speed coal mills comprise the following four types: roller-disc type medium speed mill, also called flat disc mill; a roller-bowl type medium-speed mill, also called a bowl type mill or an RP type mill, a ball-ring type medium-speed mill, also called a medium-speed ball mill or an E type mill; roller-ring type medium speed mill, also called MPS mill. The working speed of the coal mills is 50-300 r/min, so the coal mills are called medium-speed coal mills. The adaptability of the medium-speed milling coal is not as wide as that of the low-speed ball mill, the medium-speed milling coal is only suitable for soft coal and lean coal generally, the grindability coefficient of the coal is more than or equal to 50, and the moisture content of the raw coal cannot be too high (Mf is less than or equal to 19%). But the medium-speed mill has light weight, small occupied area, simple pipeline of a pulverizing system and low investment; the device also has the advantages of low power consumption, low noise and the like during operation. Medium speed coal mills of this kind are therefore currently used increasingly widely in large-capacity units. The fan mill is a rotating machine, has simple structure, convenient manufacture, small floor area and less metal consumption, thereby having low initial investment. The fan mill also has the advantages of simple powder making system, fast equipment and the like. In addition, the fan mill integrates three functions of drying, crushing and conveying, so that one fan can be omitted. Most of coal particles in the fan mill are in a suspended state, and ventilation and drying are very strong; the drying agent used can be composed of hot smoke, cold smoke and hot air. The proportion of the three media can be adjusted according to the moisture of the fire coal in the operation, the control is convenient and flexible, and the drying agent has good explosion-proof function. Experience has shown that fan mills are most suitable for milling high moisture lignite (external water Mf >19% or total moisture Mt > 30%) while also being useful for milling some softer bituminous coals. Various types of coal mills have respective advantages and disadvantages and adaptive ranges for coal types. The type selection of coal-fired boiler coal mills in power plants is very important, and firstly, consideration must be given to the type of coal to be fired and which pulverizing system is adopted, and the reliability and the economy of equipment operation need to be considered. When the operating economy of a coal mill is measured, three indexes of power consumption for powder making, consumption of metal materials for powder making, manual consumption for maintenance and repair and the like are comprehensively analyzed. Besides, the investment, the arrangement and installation conditions of the coal mill and the specific practical problems in operation are considered.

A fan coal mill direct-blowing type powder making system is a powder making system, wherein gas-powder two-phase fluid which is led out from a coal mill through a coarse powder separator and carries qualified fineness of coal powder is used as primary air and is directly blown into a hearth through a burner.

In the intermediate storage bin type coal pulverizing system, pulverized coal which is ground is firstly stored in a pulverized coal bin and then is sent into a hearth from the pulverized coal bin according to the load requirement. The direct blowing system has the disadvantages of slow response to the change of the boiler load and poor economical efficiency of low-load operation, so that a fine powder separator, a pulverized coal bin, a powder feeder, a powder discharge fan and other equipment are added in the storage bin type pulverizing system. The coal powder separated by the fine powder separator is stored in a coal powder bin and is sent into a primary air pipeline by a powder feeder. The fine powder separator adopts a cyclone separator, generally, the coal powder with the particle size of less than 10 mu m can not be separated and is discharged from the separator along with the drying medium, and the coal powder amount is about 10 percent of the coal grinding output, which is called as exhaust gas. The powder discharge fan is arranged behind the fine powder separator and is not easy to wear. Because the coal ground by the medium-speed coal mill generally has higher volatile components and better ignition and combustion performance of the coal powder, a middle storage bin type exhaust gas powder conveying system is generally adopted. Because the system is additionally provided with the pulverized coal bin, more pulverized coal is stored, the output of the coal mill is not limited by the load of a boiler any more, the coal mill can always operate under the optimal working condition, the required fineness of the pulverized coal can be ensured, and the coal mill has higher economy. Meanwhile, when the load of the boiler changes, the powder feeding amount can be directly adjusted by changing the rotating speed of the powder feeder, the load change is quickly responded, and the operation requirement of the peak shaving unit is met.

An exhaust gas powder feeding system and a hot air powder feeding system. When the quality of the coal for combustion is good, an exhaust gas powder conveying system can be adopted, exhaust gas is used as a conveying medium of primary air, and fine powder carried by the exhaust gas is mixed with pulverized coal discharged from the powder feeder and then is conveyed into a hearth for combustion. When hard-burning anthracite, poor coal or inferior bituminous coal is used, high-temperature primary air is needed to stably catch fire for burning, a hot air powder feeding intermediate storage type pulverizing system is adopted, a blower in the intermediate storage type pulverizing system heats hot air above a flue at the tail of a boiler through a preheater, and then the hot air is divided into primary air, secondary air and tertiary air to enter a hearth. The primary air uses hot air from an air preheater as a medium for conveying pulverized coal, the secondary air is used for supporting combustion, the tertiary air is used for adjusting and burning, and the exhaust air is used as the tertiary air and is sent into a hearth for burning, so that air quantities required by pulverized coal conveying, drying and burning are coordinated, and changes of moisture of coal, the pulverized coal quantity required by burning and the like are adapted. The hot air powder feeding system of the middle storage bin can preheat the pulverized coal in the air pipe in advance, is favorable for the separation of volatile matters, timely ignition and stable combustion in a hearth, and is mainly used for combusting low-volatile lean coal and anthracite. For high-volatile coal, hot air is not suitable for feeding powder to prevent the coal powder from burning out the burner nozzle due to too early ignition.

The chemical composition of coal is complex, but it can be classified into organic matter and inorganic matter, and organic matter is used as main body. The organic matter in coal mainly consists of five elements of carbon, hydrogen, oxygen, nitrogen, organic sulfur and the like. Wherein carbon, hydrogen and oxygen account for more than 95 percent of the organic substances. The volatile matter of coal means that when the coal is heated to a certain temperature, part of organic matters and mineral matters in the coal are decomposed and escaped, the escaped gas mainly comprises hydrogen, oxygen, nitrogen, sulfur and part of carbon, and most of the gas is combustible gas, so that the higher the volatile matter is, the easier the coal is to catch fire, and the more stable the combustion is. Coal of a coal-fired power plant is directly combusted and utilized, and high-value components contained in the coal cannot be effectively utilized, so that huge resource waste is caused.

Rich coal refers to the fractionation of tar yield (T) _ar,d ) Coal accounts for 7 to 12 percent, and is a recognized special coal resource. The oil-rich coal is directly used as fuel, so that the effective value is not utilized efficiently. Preliminary studies show that the high-volatile low-order bituminous coal of elm forest in northern Shaanxi is typical rich-oil coal and medium-high-oil coal, and the storage capacity exceeds 1500 hundred million tons, wherein the high-oil coal (T) is _ar,d > 12%) in excess of 150 hundred million tons. The estimation of the oil-rich coal resource in only Hami region in Xinjiang exceeds 2000 million tons, T _ar,d The content of the oil-rich coal is more than 8 percent in common, the highest content is close to 20 percent, and if the east-west region is added, the oil-rich coal resource amount is predicted to exceed 5000 hundred million tons. The coal tar in the oil-rich coal can be completely recovered through reasonable pyrolysis.

The coal upgrading and separating method is a coal utilization mode in which coal tar and hydrogen-rich synthetic gas are extracted from coal through pyrolysis, and the residual semicoke is used as a high-grade clean fuel. Coal (coal)After the carbon is upgraded and separated, the bituminous coal is converted into low-volatile-component semi-coke with extremely low water content and low volatile component with the characteristic of anthracite, and the obtained semi-coke is dried without ash-based volatile component (V) _daf ) Less than 10%, converting lignite into low-water-content and low-volatile-matter carbocoal with characteristics of bituminous coal, and drying the carbocoal to obtain ash-based volatile matter (V) _daf ) Is less than 20 percent. Coal upgrading and separation are processes of medium-low temperature pyrolysis of coal in an oxygen-isolated or non-oxidized atmosphere, and a traditional pyrolysis furnace comprises an external heating type and an internal heating type. The external heating type adopts a flame path heating mode for dry distillation, the furnace type is complex, the heat efficiency is low, the investment is about three times of that of the internal heating type, but the byproduct gas has better components, the nitrogen content is about 4 percent, and the high-quality hydrogen-rich synthetic gas is obtained. The internal heating type has poor coal gas component due to air combustion supporting, the nitrogen content reaches more than 42 percent, and the internal heating type can only be used as fuel gas for power generation at present. If the semi-coke tail gas is developed to the direction of preparing chemicals, a pure oxygen combustion-supporting mode is needed to improve the components of the coal gas. The internal heating type can only process lump coal with the grain diameter of more than or equal to 20mm, the proportion of the lump coal in the raw coal is about 20 percent, and the foam coal with the grain diameter of less than or equal to 20mm of 80 percent can not be processed.

The coal upgrading and separating production has high energy consumption intensity and large pollutant discharge amount, a great amount of phenol-ammonia wastewater is generated in a coke quenching process in the production process, the chemical oxygen demand and the ammonia nitrogen concentration of the phenol-ammonia wastewater respectively exceed 3 ten thousand milligrams per liter and 3 thousand milligrams per liter, and the pollutant content is high. Taking the semi-coke industry of the coal upgrading and separation industry in elm city of Shaanxi province as an example, the annual production amount of phenol ammonia wastewater of semi-coke enterprises in elm shenmui city is as high as 300 million tons, and the treatment capacity of the whole market is seriously insufficient. Part of phenol-ammonia wastewater is used for quenching coke, water pollutants enter the atmospheric environment after being gasified, and the discharge amount of VOCs in the semi-coke industry of Yulin city accounts for about 22 percent of the total discharge amount of VOCs in the whole city, and is a main incentive for the local increase of the atmospheric ozone concentration.

The thermal power plant consumes more than 50% of the total coal output of China, and the exhaust heat loss of the thermal power plant is the largest one of various heat losses of the coal-fired power plant boiler, and accounts for 80% or more of the total heat loss of the boiler. The main influence factor of the heat loss of the exhaust gas is the exhaust gas temperature of the boiler, and generally, the heat loss of the exhaust gas is increased by 0.6 to 1.0 percent when the exhaust gas temperature is increased by 10 ℃, and the coal consumption of the power generation is increased by about 2 g/kWh. In the existing thermal power generating units in China, the exhaust gas temperature of a boiler is generally maintained at about 125-150 ℃, the exhaust gas temperature of a lignite boiler is about 170 ℃, and the high exhaust gas temperature is a common phenomenon, so that huge energy loss is caused.

Coal upgrading and separation need to heat coal in an oxygen isolation or non-oxidation environment, and a combustion air heating method is adopted, so that the content of oxygen in a pyrolysis furnace exceeds the standard due to the sealing problem, and the exceeding oxygen reacts with carbon in the coal to generate CO ₂ Resulting in the ineffective component CO in the hydrogen-rich synthesis gas produced by the pyrolysis furnace ₂ The proportion is too high and the calorific value is reduced. O in high-temperature flue gas and medium-temperature flue gas of coal-fired power plant boiler ₂ The content is less than or equal to 4 percent, and the requirements of the pyrolysis furnace on heating gas are completely met.

There are complementarity and integration points for the combustion system of coal-fired power plants with coal upgrading separation utilization. After upgrading and separation of coal, soft coal is converted into low-volatile semi-coke with extremely low water content and low volatile matter (V) which is characterized by anthracite, and the obtained semi-coke is dried without ash-based volatile matter (V) _daf ) Less than 10%, converting the lignite into low-water content and low-volatile semi-coke with characteristics of bituminous coal, and drying the obtained semi-coke to obtain ash-free base volatile matter (V) _daf ) Less than 20 percent, greatly reducing the total moisture content of the coal as fired; the particle size of the semicoke obtained by upgrading and separating coal completely meets the specification of coal powder charged into a coal-fired power plant, the semicoke prepared by a pyrolysis system does not need to be coked, the discharge of coke-formation pollutants is eliminated, and the energy loss of coke formation is reduced; the qualified semicoke is directly input into the middle storage bin without passing through the pulverizing system, and the qualified semicoke is sent into the hearth from the middle storage bin for combustion by primary air from the air-smoke system. The coal pulverizing link is omitted, and the power consumption and pollutant emission of a coal pulverizer in a coal pulverizing system are reduced; the high temperature of the semicoke adopts hot air to send powder into the hearth, which is more favorable for exerting the characteristics of high heat value and stable combustion of the semicoke, avoids the disadvantages of difficult ignition and difficult burnout of the semicoke, and is particularly suitable for stable combustion under deep peak regulation and low load; the hydrogen-rich synthesis gas obtained by upgrading and separating the coal can be directly input into a hearth for combustion, so that the combustion stability of the boiler is improved, and the method is particularly suitable for the working condition with larger load fluctuation during deep peak regulation; the hydrogen-rich synthesis gas contains a large amount of H ₂ The hydrogen-rich synthetic gas can be combusted in the coal-fired power plant to reduce the oxidation of the dioxideCarbon emission; coal tar obtained by upgrading and separating coal is sold to the outside, so that the revenue of a coal-fired power station is increased; the wastewater separated by upgrading coal is subjected to environment-friendly treatment and can be recycled as water for a coal-fired power plant; the pyrolysis furnace is heated, and the smoke discharged from the coal-fired power station is used for replacing the combustion of the hydrogen-rich synthetic gas, so that the low-order energy of the coal-fired power station is reasonably utilized, and the more valuable hydrogen-rich synthetic gas is saved; the waste gas of the pyrolysis furnace exchanges heat with air, the heated air enters an air preheater, the air temperature is heated to 80-100 ℃ from the normal temperature (25 ℃) and enters the air preheater, the smoke exhaust temperature of the air preheater can be increased to be more than 180 ℃, the lowest metal wall temperature of a heat exchange plate can reach more than 150 ℃ and is higher than the acid dew point temperature and the crystallization temperature of ammonium bisulfate 147 ℃, and the problems of low-temperature corrosion, scaling and ammonium bisulfate blockage are fundamentally solved; the tail gas of the coal upgrading and separating pyrolysis furnace exchanges heat with air, and the tail gas after heat exchange is mixed with low-temperature furnace smoke and then enters the desulfurizing tower, so that the water consumption of the desulfurizing process can be reduced.

In the aspect of lignite power generation technology, an authorization notice number CN 101881191B is a thermal power generation system based on a high-moisture lignite predrying, upgrading and recycling technology; an authorized bulletin No. CN 102798133B, a system for drying furnace smoke and recycling water by a fan mill to grind hot air, send powder and make powder; an authorized bulletin number CN 103148495B, sodium removal and quality improvement fan mill powder and water recovery combined cycle power generation system; an authorized notice No. CN 103575068B of lignite drying water recovery and drying tail gas recycling system; an authorized bulletin number CN 104179537B is a lignite drying power generation system for recovering water in coal and an implementation method thereof; an authorized bulletin No. CN 203116058U, sodium removal pretreatment of east Junggar coal, and a flue gas fluidized drying medium-speed milling powder power generation system; an authorized bulletin No. CN 203116062U, sodium removal from high-sodium coal and a waste gas fluidization medium-speed mill direct-blowing type pulverizing power generation system; an authorized notice No. CN 203116490U is a lignite drying coal-fired system with the functions of exhaust gas heat energy and water recovery; an authorized notice No. CN 203116491U is a high-efficiency coal-burning system for taking water from coal and burning lignite; an authorized notice No. CN 204041130U is a lignite drying power generation system for recycling water in coal; the lignite high-efficiency power generation equipment has an authorized bulletin number of CN 208269182U; an authorization bulletin number CN 207350357U is a boiler device for lignite and long flame coal; application publication No. CN 107763651A discloses a method for feeding coal to a boiler and a coal feeding system thereof. The invention only solves the problem of drying and dehydrating the lignite, and the invention still does not solve the problem that volatile components in the lignite and the long flame coal are separated out along with water in the heating process of the lignite and the long flame coal, the water is separated out after the flue gas is condensed, but the volatile components are discharged outwards along with the discharged gas to cause new environmental protection problems, and the risk of explosion is also existed.

In the aspect of coupling coal upgrading separation and coal-fired power plants, an authorization notice number CN 210601586U is a coal carbonization, industrial oxygen generation and coal-fired thermal power boiler coupling process system, in the invention: firstly, raw material coal of the coal dry distillation system is pulverized coal or granular pulverized coal, and the invention does not relate to the clean and efficient utilization of biomass, solid waste, industrial solid waste, hazardous waste and the like except coal; dry distillation coal gas prepared by the coal dry distillation system is conveyed to the oxygen-enriched combustion system through a pipeline, and the coupling of semicoke obtained after coal dry distillation and a coal-fired power plant is not involved in the invention; waste water and waste gas of the coal carbonization system enter a waste treatment device and are introduced into a coal-fired thermal power boiler, and the result of introducing the waste water into the coal-fired thermal power boiler is that the combustion efficiency of the coal-fired thermal power boiler is reduced, which is contradictory to a series of invention purposes of drying and dehydrating the lignite; and fourthly, the waste water and the waste gas of the coal dry distillation system enter a waste treatment device and are introduced into the coal-fired thermal power boiler, and the result that the waste gas is introduced into the coal-fired thermal power boiler is that the combustion efficiency of the coal-fired thermal power boiler is reduced, the difficulty of subsequent pollutant discharge treatment is increased, and the pollutant discharge treatment cost is increased.

An authorized bulletin No. CN 211079033U is a process device for realizing coal carbonization by using high-temperature flue gas of a coal-fired power generation boiler. The invention is as follows: one end of a high-temperature flue gas channel is connected to the upper part of a hearth of the coal-fired power generation boiler, the other end of the high-temperature flue gas channel is connected with a coal dry distillation device, the high-temperature flue gas channel is composed of wear-resistant and heat-insulating materials capable of bearing the temperature of more than 1000 ℃, and part of high-temperature flue gas of the coal-fired power generation boiler is led out of the high-temperature flue gas channel and is introduced into the coal dry distillation device to provide dry distillation heat. Secondly, the flow control valve is arranged on the smoke channel after carbonization, and the flow of high-temperature smoke can be adjusted according to the heat required by the coal carbonization device. According to the first step and the second step, the heat of the medium coal dry distillation device comes from high-temperature flue gas of a coal-fired power plant boiler, although the flow control valve can adjust the flow of the high-temperature flue gas, the flue gas temperature cannot be adjusted by the high-temperature flue gas from a single source, the temperature adjustment of the medium coal dry distillation device can only depend on the control of the exhaust gas temperature of the coal-fired power plant boiler, and when the normal working temperature range of the medium coal dry distillation device greatly deviates from the exhaust gas temperature of the coal-fired power plant boiler, the medium coal dry distillation device cannot normally operate.

In conclusion, the simple technical development of the coal-fired power generating unit faces a bottleneck period, and the potential of the technical transformation of the existing coal-fired power generating unit is completely exploited. The coal-fired power generation industry urgently needs a comprehensive technology, the existing resources and technologies are fully utilized, the integrated comprehensive application of coal, chemical, electricity and waste is realized, the pressure of the coal-fired power generation industry is relieved on the basis of realizing energy conservation and emission reduction, the operation field of a coal-fired power plant is expanded, and the overall benefit of the coal-fired power generation industry is improved.

Disclosure of Invention

The invention provides a coupling process system of multi-fuel upgrading separation and a coal-fired power station boiler, which couples a coal upgrading separation technology, a coal drying and dewatering technology, an intermediate storage bin type hot air powder feeding technology and the existing coal-fired power generation technology.

The coal in the invention comprises bituminous coal and lignite, and does not comprise anthracite; coal with 7-12% of Tar yield (Tar, d) is preferably selected as coal, so that the yield of pyrolysis coal Tar is increased, and the economy is improved; secondary separation dry ash-free base volatile component V _daf Long flame coal and lignite > 37%. The biomass, solid waste, industrial solid waste, hazardous waste and the like are preferably selected from oil sludge, woody waste, aged waste and the like which have high heat value and low collection cost.

The invention provides a coupling process system for upgrading and separating multi-fuel and a coal-fired power station boiler, which has the working principle that: the multi-component fuel in the multi-component fuel bin 27 is input into the pyrolysis furnace 18 through a multi-component fuel delivery system 28; high-temperature furnace smoke 2 (more than 1000 ℃) taken from the upper part of a hearth 3 is conveyed to a mixer 16 through a high-temperature furnace smoke pipeline 14, medium-temperature furnace smoke 6 (320-400 ℃) taken from the front of an air preheater 7 is conveyed to the mixer 16 through a medium-temperature furnace smoke pipeline 15, the high-temperature furnace smoke 2 and the medium-temperature furnace smoke 6 are mixed in the mixer 16, the temperature of the mixed furnace smoke accords with the normal working temperature of a pyrolysis furnace 18, the mixed furnace smoke is conveyed into the pyrolysis furnace 18 to heat multi-fuel in the pyrolysis furnace 18, and the mixed furnace smoke is circulated in the pyrolysis furnace 18 by a high-temperature fan 17 in a reciprocating mode to achieve the purpose of uniform heating of the pyrolysis furnace. The oxygen content of the high-temperature flue gas and the medium-temperature flue gas is extremely low (less than or equal to 4 percent), and the high-temperature flue gas and the medium-temperature flue gas are used as heat sources to avoid deflagration accidents in the pyrolysis process.

After pyrolysis of the multi-component fuel, the bituminous coal is converted into the semi-coke with extremely low water content and low volatile matter which is characterized by anthracite, and the lignite is converted into the semi-coke with extremely low water content and low volatile matter which is characterized by the bituminous coal. The gas-powder two-phase fluid which is led out from a semicoke discharge port 19 of the pyrolysis furnace 18 and carries the semicoke with qualified fineness passes through a fine powder separator 20, the qualified semicoke is separated and sent into a semicoke intermediate storage bin 21, and the qualified semicoke in the semicoke intermediate storage bin 21 is conveyed into a hearth 3 for combustion through hot air at an outlet of an air preheater 7 through a primary air pipeline 22; according to the calculation, the lignite with moisture of 42.52% and heat productivity of 11.93MJ/kg is reduced to 14.43% after pyrolysis, the heat productivity is increased to 18.08MJ/kg, and the heat value is increased by 51.55%. If all water can be removed, the calorific value is increased to 20.755MJ/kg, which is equivalent to that the calorific value is increased by 73.97%; moisture in the lignite is pyrolyzed and does not enter a hearth, so that on one hand, the temperature of the hearth is improved, the fuel is favorably burnt out, the combustion efficiency of the fuel is improved, and the boiler efficiency is also improved and can reach more than 95%; on the other hand, the heating surface required in the furnace is correspondingly reduced, thereby reducing the initial investment of the coal-fired power plant.

Pyrolysis gas generated after pyrolysis of the multi-component fuel is input into the oil-gas separation device 30 through a pyrolysis gas pipeline 29; liquid separated by the oil-gas separation device 30 is input into a tar dehydration device 33 through a liquid conveying pipeline 31; the gas separated by the oil-gas separation device 30 is input into a desulfurization purification device 34 through a gas transmission pipeline 32; the tar treated by the tar dehydration device 33 is input into a tar storage tank 37 through a tar conveying pipeline 35 and sold to the outside; the hydrogen-rich synthetic gas treated by the desulfurization purification device 34 is input into a hydrogen-rich synthetic gas storage tank 38 through a hydrogen-rich synthetic gas conveying pipeline 36 and used as fuel of the boiler 1 and a hot blast stove 46.

Waste water generated after pyrolysis of the multi-component fuel is input into a sewage treatment device 41 through a waste water conveying pipeline 39, waste water generated by the tar dehydration device 33 is input into the sewage treatment device 41 through a waste water conveying pipeline 40, and qualified water which meets the national standard after being treated by the sewage treatment device 41 enters a coal-fired power plant water return pipeline 42 for recycling; according to the 2 x 600MW lignite coal generating set, each lignite unit uses 400 tons of lignite per hour, the total water content of the lignite is 40%, more than 280 ten thousand tons of water can be recovered all the year, and more than 176 ten thousand tons of water can be recovered all the year after 5500 hours of annual power generation, so that a large amount of coal-fired power station make-up water can be saved, the water-saving lignite generating set has remarkable water-saving benefit, and is particularly suitable for the national situation that lignite production places in Mongolian east and Xinjiang China are generally short of water.

Combustible volatile gas in the exhaust gas of the pyrolysis furnace 18 is less and has no combustion utilization value, the exhaust gas is input into the heat exchanger 10 through an exhaust gas conveying pipeline 48 to exchange heat with fresh air 49, and the air after heat exchange enters the air preheater 7; the exhaust gas after heat exchange by the heat exchanger 10 enters a mixer 11, low-temperature furnace smoke 8 at a smoke outlet of the air preheater enters the mixer 11 through a low-temperature furnace smoke pipeline 9, and the furnace smoke mixed by the exhaust gas and the low-temperature furnace smoke 8 enters a desulfurizing tower 12; the flue gas after the flue gas entering the desulfurizing tower 12 is treated by the desulfurizing and purifying device 12 is discharged into the atmosphere through a chimney 13 so as to protect the environment.

When the heat of the furnace smoke is not enough to maintain the normal operation of the pyrolysis furnace, or when the boiler 1 has an accident of non-stop and cannot provide qualified furnace smoke for heating the pyrolysis furnace 18, the hydrogen-rich synthetic gas stored in the hydrogen-rich synthetic gas storage tank 38 is input into the hot blast stove 46 through the hydrogen-rich synthetic gas conveying pipeline 43, the fresh air 49 is input into the hot blast stove 46 through the air conveying pipeline 45, the hydrogen-rich synthetic gas and the fresh air 49 are combusted in the hot blast furnace, and the combusted hot blast is input into the pyrolysis furnace 18 through the hot blast conveying pipeline 47 to provide the required heat for the pyrolysis furnace 18.

When the boiler 1 is started, the load is unstable, the working conditions need to be changed rapidly and frequently during deep peak regulation, and the like, the hydrogen-rich synthetic gas in the hydrogen-rich synthetic gas storage tank 38 is input into the hearth 3 for combustion through the hydrogen-rich synthetic gas conveying pipeline 44; the hydrogen-rich synthetic gas can obviously improve the ignition performance of the fuel, enhance the low-load stable combustion performance of the boiler, save a large amount of low-load combustion-supporting oil or operate without oil injection, and simultaneously enhance the fuel adaptability of the boiler.

Taking a 2 x 300MW bituminous coal unit as an example, the unit burns local bituminous coal, and the coal quality data is as follows:

the standard coal consumption of each 300MW unit is 300g/kWh, the annual power generation hours are 5500 hours, the price of raw coal is 1000 yuan/ton, the price of coal tar is 4000 yuan/ton, the water price is 5 yuan/ton, and the carbon emission index is 50 yuan/ton.

The fuel supply of a single unit is completely supplied by a pyrolysis system, the coal consumption of unit standard coal for power generation is reduced from 300g/kWh to 259.32g/kWh, the coal consumption of standard coal for power generation is reduced by 40.68g, and the coal consumption ratio of unit standard coal is reduced by 13.56%; 6.24 million tons of tar can be produced all the year round, and the sales income of the tar can be 2.5 million yuan per ton of tar according to the price of 4000 yuan per ton of tar; annual CO reduction ₂ 2.98 ten thousand tons of CO are discharged per ton ₂ The emission reduction value is calculated by 50 yuan, and CO is realized ₂ Reducing emission by 149 ten thousand yuan; 2 ten thousand tons of water are recycled every year, and the value is 10 ten thousand yuan; the unit increases gross profit by 2.17 million yuan per year, and has obvious economic benefit.

The fuel part of a single unit is supplied by a pyrolysis system, the rest of the fuel is used for the existing pulverizing system, a multi-fuel quality-improving separation system for processing 50 tons of raw coal per hour is built and coupled with a coal-fired power station boiler, the unit standard coal power generation coal consumption is reduced from 300g/kWh to 277.7g/kWh, the standard coal power generation coal consumption is reduced by 22.3g, and the unit standard coal power generation coal consumption proportion is reduced by 7.42%; 2.5 million tons of tar can be produced all the year round, and the sales income of the tar can be 1 million yuan per ton of tar calculated according to the 4000 yuan price of the tar; annual CO reduction ₂ Discharge 1 ten thousand tons per ton of CO ₂ Emission reduction value 50 Yuan calculation, and CO realization ₂ Emission reduction is 50 ten thousand yuan; 8250 tons of annual recycled water are 41250 yuan; 8600 million yuan hair is added to the unit year, and the economic benefit is also remarkable. The invention is suitable for ChinaOil-rich bituminous coal producing areas.

Taking a certain 2 x 600MW lignite unit as an example, the unit burns local lignite, and the coal quality data is as follows:

the standard coal consumption of each 600MW unit is 300g/kWh, the annual power generation hours are 5500 hours, the raw coal price is 300 yuan/ton, the coal tar price is 4000 yuan/ton, the water price is 5 yuan/ton, and the carbon emission index is 50 yuan/ton.

The fuel supply of a single unit is completely supplied by a pyrolysis system, the coal consumption of unit standard coal for power generation is reduced from 300g/kWh to 259.00g/kWh, the coal consumption of standard coal for power generation is reduced by 41.00g, and the coal consumption ratio of unit standard coal is reduced by 13.67%; 20.4 million tons of tar can be produced all the year round, and the sale income of the tar can be 8.2 million yuan per ton of tar according to the price of 4000 yuan per ton of tar; annual CO increase ₂ Discharge 70 ten thousand tons per ton of CO ₂ Emission reduction value is calculated by 50 yuan, and CO is increased ₂ 3500 ten thousand yuan is discharged; the annual recovery of 64 ten thousand tons of water is 320 ten thousand yuan; the unit year increases gross profit by 7.36 million yuan, and has obvious economic benefit.

The fuel part of a single unit is supplied by a pyrolysis system, the rest of the fuel is used for the existing pulverizing system, a multi-fuel quality-improving separation system for processing 50 tons of raw coal per hour is built and coupled with a coal-fired power station boiler, the power generation coal consumption of the unit standard coal is reduced from 300g/kWh to 293.37g/kWh, the power generation coal consumption of the standard coal is reduced by 6.63g, and the power generation coal consumption proportion of the unit standard coal is reduced by 1.10%; 2.2 ten thousand tons of tar can be produced all the year around, and the sale income of the tar can be 8800 ten thousand yuan all the year around according to the price of 4000 yuan per ton of tar; annual CO increase ₂ Discharge 8 ten thousand tons per ton of CO ₂ Emission reduction value is calculated by 50 yuan, and CO is increased ₂ Discharging 400 ten thousand yuan; the annual water recovery is 7 ten thousand tons, and the value is 35 ten thousand yuan; the gross profit of the unit is increased by 7900 ten thousand yuan year by year, and the economic benefit is also obvious. The invention is suitable for the oil-rich lignite production areas in China.

Description of the drawings:

FIG. 1 is a schematic diagram of a multi-fuel upgrading separation and coal-fired power plant boiler coupling process system

FIG. 2 is a schematic diagram of a multi-fuel upgrading separation and pulverization system combined with a coal-fired utility boiler coupling process system

Illustration of the drawings: the two schematic diagrams respectively represent two operation modes, and for a newly-built coal-fired power plant, the pyrolysis system can provide fuel required by 100% of output of a boiler without a set of traditional pulverizing system, so that the investment is saved, and the plant power consumption rate is reduced. For the existing coal-fired power plant, a coal pulverizing system is invested and built, and on the basis of the old coal pulverizing system, the following principle is followed for newly building a multi-fuel upgrading and separating system: the fuel supply required by the boiler output is mainly a multi-fuel upgrading and separating system, and an original pulverizing system is assisted; when the output of the multi-fuel upgrading and separating system is not enough to provide the fuel required by the combustion of the boiler, the output of the original pulverizing system needs to be increased in time to ensure the combustion of the boiler; the safety of the scheme is better in view of the fact that the original pulverizing system already meets the fuel required by 100% output of the boiler.

The specific implementation mode is as follows:

the present invention will be described in detail below with reference to embodiments and drawings, it being noted that the described embodiments are only intended to facilitate the understanding of the present invention, and do not limit it in any way.

Example 1

The embodiment provides an operation mode of a multi-fuel upgrading separation and coal-fired power plant boiler coupling process system, and as shown in fig. 1, the multi-fuel upgrading separation and coal-fired power plant boiler coupling process system comprises that multi-fuel in a multi-fuel bin 27 is input into a pyrolysis furnace 18 through a multi-fuel conveying system 28; high-temperature furnace smoke 2 taken from the upper part of a hearth 3 is conveyed to a mixer 16 through a high-temperature furnace smoke pipeline 14, medium-temperature furnace smoke 6 taken from the front of an air preheater 7 is conveyed to the mixer 16 through a medium-temperature furnace smoke pipeline 15, the high-temperature furnace smoke 2 and the medium-temperature furnace smoke 6 are mixed in the mixer 16, the temperature of the mixed furnace smoke accords with the normal working temperature of a pyrolysis furnace 18, the mixed furnace smoke is conveyed into the pyrolysis furnace 18 to heat a multi-component fuel in the pyrolysis furnace 18, and a high-temperature fan 17 circulates the mixed furnace smoke in the pyrolysis furnace 18 in a reciprocating manner, so that the aim of uniformly heating the pyrolysis furnace is fulfilled; after pyrolysis of the multi-component fuel, the bituminous coal is converted into the semi-coke with extremely low water content and low volatile matter which is characterized by anthracite, and the lignite is converted into the semi-coke with extremely low water content and low volatile matter which is characterized by the bituminous coal. The gas-powder two-phase fluid which is led out from a semicoke discharge port 19 of the pyrolysis furnace 18 and carries the semicoke with qualified fineness passes through a fine powder separator 20, the qualified semicoke is separated and sent into a semicoke intermediate storage bin 21, and the qualified semicoke in the semicoke intermediate storage bin 21 is conveyed into a hearth 3 for combustion through hot air at an outlet of an air preheater 7 through a primary air pipeline 22; pyrolysis gas generated after pyrolysis of the multi-component fuel is input into the oil-gas separation device 30 through a pyrolysis gas pipeline 29; liquid separated by the oil-gas separation device 30 is input into a tar dehydration device 33 through a liquid conveying pipeline 31; the gas separated by the oil-gas separation device 30 is input into a desulfurization purification device 34 through a gas transmission pipeline 32; the tar treated by the tar dehydration device 33 is input into a tar storage tank 37 through a tar conveying pipeline 35 and sold to the outside; the hydrogen-rich synthetic gas treated by the desulfurization and purification device 34 is input into a hydrogen-rich synthetic gas storage tank 38 through a hydrogen-rich synthetic gas conveying pipeline 36 and is used as fuel of a boiler 1 and a hot blast stove 46; waste water generated after the pyrolysis of the multi-component fuel is input into a sewage treatment device 41 through a waste water conveying pipeline 39, waste water generated by the tar dehydration device 33 is input into the sewage treatment device 41 through a waste water conveying pipeline 40, and qualified water which meets the national standard after being treated by the sewage treatment device 41 enters a coal-fired power plant water return pipeline 42 for recycling; the exhaust gas of the pyrolysis furnace 18 is input into the heat exchanger 10 through an exhaust gas conveying pipeline 48, exchanges heat with fresh air 49, and the air after heat exchange enters the air preheater 7; the exhaust gas after heat exchange by the heat exchanger 10 enters a mixer 11, low-temperature furnace smoke 8 at a smoke outlet of the air preheater is input into the mixer 11 through a low-temperature furnace smoke pipeline 9, and the furnace smoke mixed by the exhaust gas and the low-temperature furnace smoke 8 enters a desulfurizing tower 12; the flue gas after the flue gas entering the desulfurizing tower 12 is treated by the desulfurizing purification device 12 is discharged into the atmosphere through a chimney 13;

when the heat of the furnace smoke is not enough to maintain the normal operation of the pyrolysis furnace, or when the boiler 1 has a non-stop accident and cannot provide qualified furnace smoke for heating the pyrolysis furnace 18, the hydrogen-rich synthetic gas stored in the hydrogen-rich synthetic gas storage tank 38 is input into the hot blast stove 46 through the hydrogen-rich synthetic gas conveying pipeline 43, the fresh air 49 is input into the hot blast stove 46 through the air conveying pipeline 45, the hydrogen-rich synthetic gas and the fresh air 49 are combusted in the hot blast furnace, and the combusted hot blast is input into the pyrolysis furnace 18 through the hot blast conveying pipeline 47 to provide the required heat for the pyrolysis furnace 18;

when the boiler 1 is started, the load is unstable, the working condition needs to be changed rapidly and frequently during deep peak regulation, and the like, the hydrogen-rich synthetic gas in the hydrogen-rich synthetic gas storage tank 38 is input into the hearth 3 through the hydrogen-rich synthetic gas conveying pipeline 44 for combustion;

example 2

The embodiment provides an operation mode of a multi-fuel upgrading separation and pulverizing system combined with a coal-fired power plant boiler coupling process system, and as shown in fig. 2, the multi-fuel upgrading separation and pulverizing system comprises a multi-fuel storage 27 and a multi-fuel conveying system 28, wherein the multi-fuel is conveyed into a pyrolysis furnace 18; high-temperature furnace smoke 2 taken from the upper part of a hearth 3 is conveyed to a mixer 16 through a high-temperature furnace smoke pipeline 14, medium-temperature furnace smoke 6 taken from the front of an air preheater 7 is conveyed to the mixer 16 through a medium-temperature furnace smoke pipeline 15, the high-temperature furnace smoke 2 and the medium-temperature furnace smoke 6 are mixed in the mixer 16, the temperature of the mixed furnace smoke accords with the normal working temperature of a pyrolysis furnace 18, the mixed furnace smoke is conveyed into the pyrolysis furnace 18 to heat a multi-component fuel in the pyrolysis furnace 18, and a high-temperature fan 17 circulates the mixed furnace smoke in the pyrolysis furnace 18 in a reciprocating manner, so that the aim of uniformly heating the pyrolysis furnace is fulfilled; after pyrolysis of the multi-component fuel, the bituminous coal is converted into the semi-coke with extremely low water content and low volatile matter which is characterized by anthracite, and the lignite is converted into the semi-coke with extremely low water content and low volatile matter which is characterized by the bituminous coal. The gas-powder two-phase fluid which is led out from a semicoke discharge port 19 of the pyrolysis furnace 18 and carries the semicoke with qualified fineness passes through a fine powder separator 20, the qualified semicoke is separated and sent into a semicoke intermediate storage bin 21, and the qualified semicoke in the semicoke intermediate storage bin 21 is conveyed into a hearth 3 for combustion through hot air at an outlet of an air preheater 7 through a primary air pipeline 22; pyrolysis gas generated after pyrolysis of the multi-component fuel is input into the oil-gas separation device 30 through a pyrolysis gas pipeline 29; the liquid separated by the oil-gas separation device 30 is input into a tar dehydration device 33 through a liquid conveying pipeline 31; the gas separated by the oil-gas separation device 30 is input into a desulfurization purification device 34 through a gas transmission pipeline 32; the tar treated by the tar dehydration device 33 is input into a tar storage tank 37 through a tar conveying pipeline 35 and sold to the outside; the hydrogen-rich synthetic gas treated by the desulfurization and purification device 34 is input into a hydrogen-rich synthetic gas storage tank 38 through a hydrogen-rich synthetic gas conveying pipeline 36 and is used as fuel of a boiler 1 and a hot blast stove 46; waste water generated after the pyrolysis of the multi-component fuel is input into a sewage treatment device 41 through a waste water conveying pipeline 39, waste water generated by the tar dehydration device 33 is input into the sewage treatment device 41 through a waste water conveying pipeline 40, and qualified water which meets the national standard after being treated by the sewage treatment device 41 enters a coal-fired power plant water return pipeline 42 for recycling; the exhaust gas of the pyrolysis furnace 18 is input into the heat exchanger 10 through an exhaust gas conveying pipeline 48, exchanges heat with fresh air 49, and the air after heat exchange enters the air preheater 7; the exhaust gas after heat exchange by the heat exchanger 10 enters a mixer 11, low-temperature furnace smoke 8 at a smoke outlet of the air preheater enters the mixer 11 through a low-temperature furnace smoke pipeline 9, and the furnace smoke mixed by the exhaust gas and the low-temperature furnace smoke 8 enters a desulfurizing tower 12; the flue gas after the flue gas entering the desulfurizing tower 12 is treated by the desulfurizing purification device 12 is discharged into the atmosphere through a chimney 13;

When the boiler 1 is started, the load is unstable, the working conditions need to be changed rapidly and frequently during deep peak regulation, and the like, the hydrogen-rich synthetic gas in the hydrogen-rich synthetic gas storage tank 38 is input into the hearth 3 for combustion through the hydrogen-rich synthetic gas conveying pipeline 44;

raw coal in a raw coal bin 24 is input into a coal mill 26 through a raw coal conveying system 25, and prepared coal powder is input into a hearth 3 to be combusted; the unqualified semicoke separated by the fine powder separator 20 is sent to a raw coal bin 24, mixed with raw coal, and then sent to a coal mill 26 through a raw coal conveying system 25, and the prepared coal powder is sent to a hearth 3 for combustion.

Illustration of the drawings:

1. boiler body

2. High-temperature furnace smoke

3. Hearth box

4. Denitration device

5. First-level coal economizer

6. Medium temperature furnace smoke

7. Air preheater

8. Low-temperature furnace smoke

9. Low-temperature furnace smoke pipeline

10. Heat exchanger

11. Mixing device

12. Desulfurizing tower

13. Chimney

14. High-temperature furnace smoke pipeline

15. Smoke pipeline of medium-temperature furnace

16. Mixing device

17. High-temperature fan

18. Pyrolysis furnace

19. Semi-coke discharge port

20. Fine powder separator

21. Intermediate storage bin for semicoke

22. Primary air duct

23. Unqualified semicoke conveying pipeline

24. Raw coal bin

25. Raw coal conveying system

26. Coal mill

27. Multi-element fuel bin

28. Multi-fuel delivery system

29. Pyrolysis gas pipeline

30. Oil-gas separation device

31. Liquid conveying pipeline

32. Gas delivery pipeline

33. Tar dewatering device

34. Desulfurization purification device

35. Tar conveying pipeline

36. Hydrogen-rich synthetic gas conveying pipeline

37. Tar storage tank

38. Hydrogen-rich synthetic gas storage tank

39. Waste water conveying pipeline

40. Waste water conveying pipeline

41. Sewage treatment device

42. Power plant return water pipeline

43. Hydrogen-rich synthetic gas conveying pipeline

44. Hydrogen-rich synthetic gas conveying pipeline

45. Air delivery pipeline

46. Hot-blast stove

47. Hot air delivery pipeline

48. Ventilation air methane conveying pipeline

49. Fresh air

Finally, it should be noted that, the ordinary skilled in the art should recognize that the above embodiments are only for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, and that the changes and modifications of the above embodiments are within the scope of the claims of the present invention as long as they are within the spirit of the present invention.

Claims

1. A multi-fuel upgrading separation and coal-fired power plant boiler coupling process system comprises a boiler body, a wind and smoke system, a powder making system, a combustion system and a pyrolysis system, and is characterized in that multi-fuel is pyrolyzed in the pyrolysis system, and pyrolysis products are semi-coke, tar, hydrogen-rich synthesis gas and water; the qualified semicoke is directly input into the intermediate storage bin without passing through a pulverizing system, and the qualified semicoke is sent into a hearth from the intermediate storage bin for combustion by primary air from an air-smoke system; pyrolysis gas is from pyrolysis oven input oil gas separator, and the liquid after the separation inputs the tar storage tank after tar dewatering device dehydration, and the gas after the separation is handled through desulfurization purifier and is input hydrogen-rich synthetic gas storage tank, and hydrogen-rich synthetic gas sends into the furnace burning through combustion system, and waste water input sewage treatment plant gets into coal fired power plant water treatment system recycle after handling, and the atmosphere is arranged into after the pyrolysis exhaust gas is handled through the wind cigarette system.

2. The coupling process system of the multi-fuel upgrading separation and coal-fired power plant boiler as claimed in claim 1, wherein the multi-fuel can be one of coal, biomass, solid waste, industrial solid waste and hazardous waste, or a mixture of two or more of coal, biomass, solid waste, industrial solid waste and hazardous waste.

3. The coupling process system of the multi-fuel quality improvement separation and coal-fired power plant boiler as claimed in claim 1, wherein the multi-fuel quality improvement separation is performed by a pyrolysis system, and the products obtained by quality improvement separation are semi-coke, tar, hydrogen-rich synthesis gas and water.

4. The system of claim 1, wherein the pyrolysis system may or may not use a catalyst, preferably a pyrolysis system with on-line catalytic cracking.

5. The multi-fuel quality-improving separation and coal-fired power plant boiler coupling process system according to claim 1, wherein the semicoke produced by the pyrolysis system does not need to be charred, the qualified semicoke is directly input into the intermediate storage bin without passing through the pulverizing system, and the qualified semicoke is fed into the hearth for combustion from the intermediate storage bin by primary air from the air-smoke system.

6. The system of claim 1, wherein the heating source of the pyrolysis system is selected from the group consisting of furnace smoke and hot air generated by burning a hydrogen-rich syngas.