CN211734273U

CN211734273U - High-efficiency coal gasification-gas boiler system and coal energy utilization system

Info

Publication number: CN211734273U
Application number: CN201920197921.XU
Authority: CN
Inventors: 陈晓辉
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-02-14
Filing date: 2019-02-14
Publication date: 2020-10-23
Anticipated expiration: 2029-02-14

Abstract

The invention relates to a high-efficiency coal gasification-gas boiler system and a coal energy utilization system, in particular to a coal gasification-gas boiler system which is composed of a gasification agent generation and gas distribution system, a closed coal conveying and gas distribution system, a coal gas space, a coal gas grid and gas distribution system, a combustion space, a blast and gas distribution system, an ash residue space, a closed slag tapping system, a heat energy exchange system and the like. The uniqueness of the system comprises that the gasification agent generation and gas distribution system generates the gasification agent with the temperature, flow and component proportion which can be effectively controlled according to the coal material and the process requirement, and the gasification agent generation and gas distribution system and the closed coal material conveying and gas distribution system provide the space structure and the hydromechanics condition which are required by the gasification reaction when the coal material is fully contacted with the gasification agent, so that the coal material can be gasified efficiently in the boiler and the hot gas can be directly combusted, and the energy can be efficiently utilized.

Description

High-efficiency coal gasification-gas boiler system and coal energy utilization system

Technical Field

The invention relates to an efficient coal gasification-gas boiler system and a coal energy utilization system, which realize clean and efficient utilization of coal, in particular to a coal gasification-gas boiler and system and a clean and efficient utilization system of coal energy.

Background

The natural resource structure of oil shortage, gas shortage and coal resource abundance in China relatively determines the important position of the energy structure and coal in industry and economy in China for a long time. How to exert the advantages, cleanly utilize relatively rich coal resources in China, improve the technical level of energy and industry in China, and solve the problems of atmospheric pollution and low energy efficiency becomes an important development direction of energy and resource utilization, energy conservation and environmental protection in China. From coal-fired power generation to various types and scales of high-energy-consumption industries and industrial production and civil fields, the existing coal-fired boiler is the most economical and basic method and means for realizing coal energy utilization, but is also one of important pollution sources causing air pollution nationwide. The coal-fired boiler effectively solves the problems of low energy efficiency and high pollution which are difficult to solve for a long time in the existing coal-fired boiler, realizes the clean and efficient utilization of coal, and has great significance for energy safety, industrial and agricultural production, mass life, atmosphere and environmental protection in China.

In the course of the long-term development of modern industry, various coal-fired boilers of a wide range of applications and different sizes have been produced. The basic function of the device is to provide a method for realizing the contact and combustion of the coal material and air and a required structure and function, complete the release of heat energy contained in the coal material and generate high-temperature flue gas; and the high-temperature hot flue gas is converted into steam through a heat energy exchange system, and the steam can be further used for power generation. In order to improve the combustion efficiency of coal, the heat energy utilization rate of a system and reduce the pollution emission, the existing coal-fired boiler which is continuously developed and improved is a heat production equipment system for realizing the direct combustion of coal.

The existing industrial coal-fired boiler technology and equipment system generally realize coal combustion under the normal pressure condition and classify according to the character characteristics of the coal and the material conveying mode, wherein the common three main types comprise a grate furnace or a chain furnace suitable for lump coal, a fluidized bed boiler suitable for coal particles and a pulverized coal boiler suitable for pulverized coal. Although various existing coal-fired boiler technologies and equipment systems have the structural and technical characteristics and relative advantages, the problems of coal combustion efficiency, system heat energy utilization efficiency, pollutant discharge and the like exist because the direct combustion of coal can only be completed. The problems are the serious problems which generally exist in the current coal energy utilization and cannot be solved for a long time, and the effective solving method is to generate hot coal gas by gasifying clean and efficient coal, directly complete the clean combustion and the heat energy release of the hot coal gas and realize the clean and efficient energy utilization of the coal.

The existing coal-fired boiler and the technical characteristics

The core characteristic of the existing coal-fired boiler is that coal and oxidant (air, oxygen-enriched or pure oxygen) are directly subjected to combustion reaction in a hearth, so that the heat energy release of coal is realized. The method is characterized in that three main conveying and moving modes of coal materials conveyed into a hearth of the coal-fired boiler can be summarized, and the functions and the effects of the coal-fired boilers are comprehensively compared, particularly the interaction of an oxidant and the coal materials, the combustion reaction and the heat energy release.

1. Grate boiler/chain boiler:

a chain grate boiler, also called a chain grate boiler or a grate boiler, is the most mechanized combustion equipment in the application of industrial coal-fired boilers. The combustion mode is that the movable fire bed is used for combustion, mechanical coal feeding is realized by adopting a chain grate, a blower and a draught fan are matched for mechanical ventilation, and a scraper type slag discharging machine is arranged for realizing automatic slag discharging. Coal enters the fire grate through the coal feeding hopper, enters the furnace along with the movement of the fire grate to contact with air in the furnace, and starts the combustion process of the coal. The burnt coal slag is discharged to a slag discharging well at the tail part of the grate along with the movement of the grate.

The ignition of coal mainly depends on the flame of the hearth and the radiant heat of the furnace arch, so that the coal on the hearth is ignited firstly and then gradually burns downwards, and the coal is ignited on a single side. Such combustion processes result in significant zonal stratification on the grate. After entering the hearth, the coal gradually moves from front to back along with the grate. The front part of the grate is a new coal combustion preparation area which is mainly used for preheating and drying coal materials, and then the volatile components in the coal materials are analyzed to form coke and enter a combustion area; the middle part of the fire grate is a coke burning zone, the temperature of the zone is very high, and oxidation and reduction reaction processes are carried out simultaneously to release a large amount of heat; the back of the grate is an ash burnout area, and the coke left in the ash is continuously combusted and releases heat. High-temperature flue gas generated in the whole process of the coal material in the hearth enters a heat exchange area through a furnace barrel to complete heat energy conversion to generate steam.

The grate boiler has the characteristics of simple technology and furnace body structure and stable operation, but has the problems of poor ignition condition of coal materials, difficult full combustion of the coal materials, excessive blast, poor adaptability of coal types, low combustion efficiency of coal, low heat energy efficiency of a system, serious pollution emission, few applicable coal types, limitation of the scale of the boiler by materials and mechanical equipment and the like.

2. Circulating fluidized bed boiler:

the circulating fluidized bed boiler, also called fluidized bed boiler, is the coal combustion boiler technology with the highest degree of industrialization, and utilizes pressurized air to generate coal fluidization, and realizes the fluidized combustion of the coal, thereby completing the release and exchange of heat energy. The main structure of the device comprises a combustion chamber, a circulating furnace (comprising a high-temperature gas-solid separation and material returning system) part and a heat energy exchange part, the capacity range is wide, and the device can be expanded to 600MW grade or above which can be accepted by the power industry.

The circulating fluidized bed boiler adopts ignition under a bed, and classified blasting and combustion are carried out; the ash slag is separated by medium temperature and discharged in dry mode by a spiral or scraper type slag discharging device. The furnace chamber is the key for ensuring the full combustion of the fuel, and a turbulent bed and a proper furnace chamber section are adopted to keep a certain coal fluidization speed. The coal material completes the combustion process in the circulating fluidized bed furnace, converts chemical energy into heat energy of high-temperature flue gas through combustion, and converts water into saturated steam into superheated steam through absorption and conversion of a heating surface of a rear-end heat exchange system.

The circulating fluidized bed boiler has high reliability and stability, high coal combustion efficiency, large-scale application, wide coal adaptation range and high adaptability to inferior fuel. But the equipment system has the problems of easy abrasion, complex structure, difficult full combustion of coal materials, excessive blast, low heat energy utilization rate, high emission of fly ash and particulate matters and the like.

3. Pulverized coal fired boiler:

the pulverized coal boiler is a suspension combustion boiler taking pulverized coal as coal. The hearth is a large space surrounded by a water wall furnace wall, pulverized coal (the diameter is 0.05-0.1 mm) which is ground is sprayed into the hearth by a pulverized coal burner through a feeder and an air-powder mixing pipeline, pulverized coal suspension combustion with relatively high efficiency is formed in the combustion space, and heat energy contained in the coal is released to generate high-temperature flue gas; the heat energy conversion from high-temperature flue gas to steam is completed through radiation and convection heat exchange by a heat exchange system. The pulverized coal furnace has a relatively simple structure, is suitable for various coals, is one of main forms of modern coal-fired boilers, is suitable for large boilers in power plants and industrial boilers with larger capacity, and needs to be provided with coal grinding equipment and corresponding high-efficiency dust removal devices.

The suspension combustion process of the pulverized coal formed when the pulverized coal enters the pulverized coal boiler can be divided into a preparation stage, a combustion stage and a burnout stage before ignition; the corresponding furnace chamber can also be divided into three areas: the vicinity of the outlet of the burner is an ignition area, the upper part of the outlet is a combustion area, and the area above the combustion area to the outlet of the hearth is a burnout area. The suspension combustion of the pulverized coal in the combustion space is completed by controlling the mixing ratio of the pulverized coal and air entering the pulverized coal boiler and the air quantity of the pulverized coal combustion in different areas.

Although the pulverized coal boiler has the advantages of relatively simple structure, multiple applicable coals, high combustion efficiency, large-scale production and the like, the pulverized coal boiler has the problems of complex organization and process of combustion working conditions, more factors influencing combustion stability, difficult full combustion of coal materials, excessive air blowing and the like. Because the preparation of the pulverized coal generates a large amount of dust, the amount of fly ash generated by the combustion of the pulverized coal is as high as 80-90%, and a high-efficiency dust removal device is required to be equipped. In addition, pulverized coal combustion generates local high temperature and a large amount of nitrogen oxides and fine particulate pollutants, which are not beneficial to atmospheric pollution treatment.

The coal-fired technology adopted by the existing main coal-fired boiler, the working principle and the structural characteristics of the coal-fired boiler are compared and analyzed, and the following can be concluded: no matter the existing grate boiler, circulating fluidized bed boiler and pulverized coal boiler, the aim of improving the combustion efficiency of coal materials to realize full combustion is achieved, and the efficient release of heat energy contained in the coal materials is realized by directly adding air (oxidant) into a coal-fired hearth, mixing with the coal materials (pulverized coal, coal particles or coal blocks), contacting and combusting. The sectional combustion of the coal material is realized by controlling the air quantity entering the coal-fired boiler from different positions, and the full combustion of the coal material is completed. Thus, the prior art coal-fired technology and coal-fired boilers suffer from three major disadvantages:

1) air (oxidant) is directly blown into the coal-fired boiler to contact and burn with the coal material, so that heat energy contained in the coal material is released, and local high-temperature and high-nitrogen oxide is produced; in order to ensure that the coal materials are fully combusted as far as possible, the coal-fired boiler works in an excessive blowing combustion state, so that the system has low heat energy utilization efficiency and high emission of particulate matters and nitric oxides;

2) the local high temperature produced by the combustion of the air and the coal in the coal-fired boiler can cause the fusion of the coal and the fly ash, so that the adhesion and the corrosion appear on the inner wall of the coal-fired boiler, and the heat efficiency, the service life and the operation safety of the coal-fired boiler are seriously influenced;

3) coal-fired boilers, particularly pulverized coal boilers and circulating fluidized bed boilers, operate by maintaining and completing combustion of coal through excessive air blowing, so that a large amount of dust, fly ash and fine particles are generated, serious dust and particle emission is caused, and the burden of emission reduction of particles at the tail end and the equipment and operating cost of emission reduction are increased.

Disclosure of Invention

The invention aims to provide an efficient coal gasification-gas boiler system and a coal energy utilization system which have high coal combustion efficiency and energy efficiency and low pollution emission and can effectively realize clean and efficient utilization of coal, and effectively solve the problems of insufficient coal combustion, low energy utilization efficiency, high atmospheric pollution emission, high equipment operation cost and the like in the prior coal-fired boiler technology; on the basis of the coal gasification-gas boiler and the system, a new clean utilization system of coal energy is established and formed, and clean and efficient utilization of the coal energy is realized.

In order to achieve the above purposes, the technical scheme adopted by the invention is as follows:

an efficient coal gasification-gas boiler system and a coal energy utilization system are disclosed, which utilize medium-high temperature oxygen-lacking oxidant to realize efficient coal gasification of coal material in a hearth to generate hot coal gas, and then complete heat energy release and exchange in a coal gas combustion mode; the peripheral equipment and the configuration of the general equipment or parts are the same as or similar to that of the existing coal-fired boilers with various main types and scales, and the working temperature range and the function of the heat energy absorption and exchange equipment or the steam-water system are also the same as or similar to that of the existing equipment; the method is characterized in that:

the hearth or the combustion system of the high-efficiency coal gasification-gas boiler system and the coal energy utilization system comprises the following functional areas, equipment systems, connection modes and system structures: a gasifying agent generating and gas distributing system (1), a closed coal conveying and gas distributing system (2), a coal gas space (3), a coal gas grid and gas distributing system (4), a combustion space (5), a primary air gas distributing system (6.1) and a secondary air gas distributing system (6.2) of a blast and gas distributing system, an ash residue space (7), a closed slag discharging system (8) and a general boiler heat energy exchange system or a steam-water system;

the gasification agent generating and gas distributing system (1) consists of a gasification agent generating device, a gasification agent conveying pipeline, a gas distribution structure which is connected with the gasification agent conveying pipeline and realizes the function of distributing the gasification agent, and a gas distributing device which consists of an exhaust outlet, can generate a medium-high temperature oxygen-lacking oxidant with the temperature, the flow rate, the component proportion and the like which can be effectively controlled, and comprises the main components of carbon dioxide (CO2), water (H2O) and nitrogen (N2); under the action of pressure difference, a medium-high temperature oxygen-lacking oxidant enters a boiler through a pipeline and a gas distribution device, is directly contacted with coal materials from a closed coal material conveying and coal distribution system (2) and generates a coal gasification reaction, and continuously generates hot coal gas for combustion; the gasification agent generated by the gasification agent generating device is directly contacted with the coal material from the closed coal material conveying and coal distributing system (2) through a gasification agent conveying pipeline and a gasification agent exhaust port of a gasification agent gas distributing device, and coal gasification reaction is carried out, so that hot coal gas for combustion is continuously generated;

the closed coal material conveying and distributing system (2) consists of a closed automatic coal feeding device and a coal material conveying device, is combined with the gasification agent generation and distributing system (1) to form a space structure and a hydromechanics condition which are needed by the contact of the coal material and the medium-high temperature oxygen-lacking oxidant and the coal gasification reaction, realizes that the coal material is conveyed into a boiler by a closed material conveying supporting body such as a spiral, a scraping bucket or a scraping plate under the air-tight condition in a continuous or intermittent mode, and is distributed by a coal distributing device with the coal material conveying and corresponding material distribution functions, such as a fixed bed, a chain grate, a circulating fluidized bed, pulverized coal spraying or the combination thereof, and then is directly contacted with the medium-high temperature oxygen-lacking oxidant from the gasification agent generation and distributing system (1) to generate the coal gasification reaction, and continuously generates hot coal gas for combustion;

the gas space (3) collects and buffers hot gas generated in the coal gasification process, so that the hot gas passes through a gas grid and a gas distribution system (4) with the functions of dust suppression, heat storage, gas distribution and the like; after the hot coal gas passes through a coal gas grid and a gas distribution system (4) which are formed by a gas distribution functional structure, the hot coal gas keeps entering a combustion space (5) through a coal gas flowing mode and direction and a gas distribution state which are formed by the coal gas grid and the gas distribution system (4), and is fully mixed and combusted with air from a primary air gas distribution system (6.1) and a secondary air gas distribution system (6.2) of a blast and gas distribution system respectively to produce radiant heat and high-temperature tail gas which can be converted into steam;

ash generated after coal gasification falls on an ash collecting inclined plane with a large angle under the action of gravity, is collected to the bottom of an ash space (7), and is discharged out of the coal gasification-gas boiler system in a continuous or intermittent mode through a closed slag discharging system (8) consisting of a closed slag discharging device or equipment with a material conveying function;

the heat exchange or steam-water system of the high-efficiency coal gasification-gas boiler system and the coal energy utilization system is the same as the existing coal-fired and other heat energy boiler systems, and mainly comprises universal equipment parts and equipment systems such as a radiation heat exchanger, an economizer, a superheater, an air preheater and the like, so that the steam and heat energy generated by heat energy exchange are recycled;

the high-efficiency coal gasification-gas boiler system and the coal energy utilization system realize material and heat energy balance of the boiler and a heat energy system and high-efficiency conversion and utilization of coal energy by adjusting the coal feeding amount and cooperatively adjusting parameters such as temperature, flow, component proportion and the like of a gasification agent and the blast volume of hot gas combustion air according to the steam load, power generation load or industrial application load requirement of the high-efficiency coal gasification-gas boiler system and the coal energy utilization system.

An efficient coal gasification-gas boiler system and a coal energy utilization system are disclosed, which utilize medium-high temperature oxygen-lacking oxidant to realize efficient coal gasification of coal material in a hearth to generate hot coal gas, and then complete heat energy release and exchange in a coal gas combustion mode; the peripheral equipment and the configuration of the general equipment or parts are the same as or similar to that of the existing coal-fired boilers with various main types and scales, and the working temperature range and the function of the heat energy absorption and exchange equipment or the steam-water system are also the same as or similar to that of the existing equipment;

the gasification agent generating and gas distributing system (1) consists of a gasification agent generating device, a gasification agent conveying pipeline, a gas distribution structure which is connected with the gasification agent conveying pipeline and realizes the function of distributing the gasification agent, and a gas distributing device which is formed by an exhaust outlet, generates a medium-high temperature oxygen-lacking oxidant with the effectively controllable temperature, flow, component proportion and the like, and mainly comprises carbon dioxide (CO2), water (H2O) and nitrogen (N2); under the action of pressure difference, a medium-high temperature oxygen-lacking oxidant enters a boiler through a pipeline and a gas distribution device, is directly contacted with coal materials from a closed coal material conveying and coal distribution system (2) and generates a coal gasification reaction, and continuously generates hot coal gas for combustion; the gasification agent generated by the gasification agent generating device is directly contacted with the coal material from the closed coal material conveying and coal distributing system (2) through a gasification agent conveying pipeline and a gasification agent exhaust port of a gasification agent gas distributing device, and coal gasification reaction is carried out, so that hot coal gas for combustion is continuously generated;

the closed coal material conveying and distributing system (2) consists of a closed automatic coal feeding device and a coal material conveying device, is combined with the gasification agent generation and gas distribution system (1) to form a space structure and a hydromechanical condition which are needed by the contact of the coal material and the medium-high temperature oxygen-lacking oxidant and the coal gasification reaction, realizes that the coal material is conveyed into a boiler through a closed material conveying supporting body such as a spiral, a scraping bucket or a scraping plate under the air-tight condition in a continuous or intermittent mode, completes the coal distribution through a coal material conveying and corresponding material distribution mode coal distributing device such as a fixed bed, a chain grate, a circulating fluidized bed, a pulverized coal spraying material or the combination thereof, and then is in direct contact with the medium-high temperature oxygen-lacking oxidant from the gasification agent generation and gas distribution system (1) to generate the coal gasification reaction, and continuously generates hot coal gas for combustion;

the gas space (3) collects and buffers hot gas generated in the coal gasification process, so that the hot gas passes through a gas grid and a gas distribution system (4) with the functions of dust suppression, heat storage, gas distribution and the like; hot coal gas enters a combustion space (5) through a coal gas grid and a gas distribution system (4) formed by a gas distribution functional structure in a flowing mode and a direction of the formed coal gas and a gas distribution mode, and is fully mixed and combusted with air from a primary air gas distribution system (6.1) and a secondary air gas distribution system (6.2) of a blast and gas distribution system respectively to produce radiant heat and high-temperature tail gas which can be converted into steam;

ash slag generated after coal gasification falls on an ash slag collecting inclined plane with a large angle under the action of gravity, is collected to the bottom of an ash slag space (7), and is discharged out of a coal gasification-gas boiler system in a continuous or intermittent mode through a closed slag discharging system (8) formed by a slag discharging device or equipment formed by a closed functional structure;

The high-efficiency coal gasification-gas boiler system and the coal energy utilization system are characterized in that the coal gasification-gas boiler and the energy utilization system have the following operation steps and technological processes:

step 1, starting an equipment system under the conditions of coal gasification-gas boiler empty load and no coal material in a boiler, and properly supplying air to a primary air distribution system (6.1) and a secondary air distribution system (6.2) of an air blowing and air distribution system; an ignition torch is established in a combustion space (5) by utilizing external energy such as natural gas or LNG to preheat a coal gasification-gas boiler system, a medium-high temperature oxygen-depleted oxidant generating device is started and preheated, and the medium-high temperature oxygen-depleted oxidant is generated.

Step 2, after the boiler system reaches the preheating temperature and the medium-high temperature oxygen-depleted oxidant generating device enters a stable working state and starts to generate the medium-high temperature oxygen-depleted oxidant, starting the closed coal conveying and coal distributing system (2) and starting to convey the coal into the boiler; under the action of medium-high temperature oxygen-lacking oxidant, coal gasification reaction is carried out on the coal material and hot coal gas is generated; under the ignition effect of the ignition torch, the hot coal gas is ignited in the combustion space (5) and gradually forms stable combustion.

Step 3, after the hot coal gas forms stable combustion in the combustion space (5), gradually shutting down the ignition torch, and enabling the coal gasification-gas boiler system to enter a stable operation state; all hot coal gas generated by coal gasification is continuously and stably combusted in the combustion space (5), and heat energy is released to generate high-temperature tail gas; the heat exchange system converts the high temperature tail gas into steam.

Step 4, regulating the gasification amount of coal by coordinately controlling the feeding amount of coal and the generation amount of a gasification agent in the normal operation process of the coal gasification-gas boiler system; the gas combustion and tail gas emission states are controlled and adjusted by adjusting the blast volume; the heat exchange and slag tapping system normally operates, and the coal gasification-gas boiler system maintains continuous and stable operation.

According to the high-efficiency coal gasification-gas boiler system and the coal energy utilization system, internal or external energy is used for utilizing the medium-high temperature oxygen-lacking oxidant which can be effectively controlled in temperature, flow, component proportion and the like generated by clean and high-efficiency combustion of gas fuel; the coal material is subjected to coal gasification reaction under the action of a medium-high temperature oxygen-lacking oxidant to generate hot coal gas, and the hot coal gas is directly combusted in a combustion space (5) under the action of an oxidant (primary air and secondary air) to complete low-excess air gas combustion, so that the combustion efficiency, the energy utilization rate and the overall thermal efficiency of a system are obviously improved, and the high-efficiency utilization of coal energy is realized.

According to the efficient coal gasification-gas boiler system and the coal energy utilization system, the medium-high temperature oxygen-lacking oxidant is utilized to realize effective control of coal gasification and optimization of coal gasification conditions and process, the generation of pollutants such as nitric oxide, sulfur oxide, particulate matters and coal tar and the emission reduction cost of the pollutants are reduced to the maximum extent, and clean utilization of coal energy is realized.

The efficient coal gasification-gas boiler system and the coal energy utilization system change the working principle and equipment system structure of the existing coal-fired boiler system, save or simplify the preparation process of related auxiliary equipment and coal materials, and reduce the operation cost of the boiler equipment system, the investment of pollutant emission reduction equipment and the operation cost of emission reduction equipment.

Drawings

The invention has the following drawings:

FIG. 1 is a schematic structural diagram of a coal gasification-gas boiler and coal energy utilization system.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

The invention comprises a coal gasification-gas boiler and a coal energy utilization system.

The system structure of the high-efficiency coal gasification-gas boiler system and the coal energy utilization system is shown in the attached drawing 1 (the structural schematic diagram of the coal gasification-gas boiler and the coal energy utilization system, which is not shown and is not detailed in detail, of equipment systems, implementation, technical methods and the like, and the implementation of the prior art and other related auxiliary units, structures, equipment, systems, process technologies, flows and the like which are familiar and adopted by technical engineers in the field can meet the requirements of various applications, functions, costs and the like, and has various specific implementation modes. Which comprises the following steps:

embodiment 1:

the closed coal conveying and distributing system (2) comprises a structure and a design with an air closing function at a coal input end, a coal conveying equipment structure and a function which are basically the same as or similar to those of the existing grate boiler or a chain grate boiler, and a spatial structure and a function which are combined with a gasification agent generation and gas distribution system (1) to form a medium-high temperature oxygen-depleted gasification agent provided from the lower part of a coal grate. The coal material is required to be non-sticky or weakly sticky coal blocks and coal particles; the medium-high temperature oxygen-lacking oxidant which is generated by the gasifying agent generation and gas distribution system (1), has the transmission temperature, the component proportion and the like and can be effectively controlled according to the coal quality, the load of a boiler system and the operation process requirement. Under the action of pressure difference, the medium-high temperature oxygen-poor oxidant is transmitted to the gas distribution system (1) through the gasification agent and is directly and fully contacted with the coal material through gas distribution to generate gasification reaction, so that the clean and efficient gasification of the coal material is realized.

Hot coal gas generated by continuous gasification of coal materials under the action of a medium-high temperature oxygen-lacking oxidant is collected, buffered and stabilized in a coal gas space (3), enters a combustion space (5) through a coal gas grid and a gas distribution system (4), is mixed with air blown in by a primary air distribution system (6.1) and a secondary air distribution system (6.2) of a blast and gas distribution system to be combusted, releases heat energy, and generates high-temperature tail gas; it is produced into steam through a heat exchange system, and the steam is discharged after being purified.

The main components of the medium-high temperature oxygen-lacking oxidant, such as temperature, flow rate, component proportion and the like generated in the gasifying agent generation and gas distribution system (1) and capable of being effectively controlled according to coal quality, boiler system load and operation process requirements, are carbon dioxide (CO2), water (H2O) and nitrogen (N2).

The closed coal material conveying and coal distributing system (2) effectively realizes that a proper amount of coal material is conveyed into a hearth of a coal gasification-gas boiler in an intermittent or continuous mode under the condition of being isolated from external air, and is in direct contact with a gasification agent generated by the gas distributing system (1) and an input medium-high temperature oxygen-lacking oxidant to generate coal gasification reaction so as to generate hot coal gas.

The ash and slag generated after the coal material is gasified are collected in an ash and slag space (7) and are effectively discharged out of the coal gasification-gas boiler and the coal energy utilization system through a closed slag discharging system (8).

The efficient coal gasification-gas boiler system and the coal energy utilization system adopt the implementation method which is the same as or similar to the technical equipment and the technical system of the existing chain grate boiler or grate furnace boiler, and the technology and the method which can be effectively implemented by professional engineering technicians in the technical field of coal gasification and gas fuel combustion, and the specific technical contents, details, steps and methods are not detailed herein.

Embodiment 2:

airtight coal material is carried and cloth coal system (2), airtight coal material is carried and is arranged coal system and includes: the device has a closed structure with the function of isolating air at the coal input end, and the device and the function of conveying and dynamically fluidizing the coal which are basically the same as or similar to the prior circulating fluidized bed boiler. The gasification agent generation and gas distribution system (1) utilizes internal or external energy to generate medium-high temperature oxygen-lacking oxidant with effectively controllable temperature, flow, component proportion and the like. The coal material enters a coal gas space (3) under the action of the gas power of a medium-high temperature oxygen-lacking oxidant from a gasification agent generation and gas distribution system (1) positioned at the bottom of the fluidized bed, presents and maintains a dynamic fluidization state, and is fully mixed with the gasification agent and subjected to coal gasification reaction to generate hot coal gas, so that the high-efficiency gasification of the coal material is realized. The coal gasification-gas boiler and the coal energy utilization system have wide applicable coal types and coal quality range, and can be sticky, weakly sticky and non-sticky; low, medium and high calorific value coals; the coal material granularity can be coal powder, coal particles or small coal blocks.

The closed coal material conveying and coal distributing system (2) effectively realizes that a proper amount of coal material is conveyed into a hearth of a coal gasification-gas boiler in an intermittent or continuous mode under the condition of being isolated from external air, the coal material is directly contacted and fully mixed with a medium-high temperature oxygen-lacking oxidant generated by a gasification agent generation and gas distributing system (1), a stable dynamic fluidized state is formed, and efficient coal gasification reaction is carried out to generate hot coal gas.

The efficient coal gasification-gas boiler system and the coal energy utilization system adopt the implementation method which is the same as or similar to the existing circulating fluidized bed boiler technical equipment and technical system, and the technology and the method which can be effectively implemented by professional engineers in the technical fields of coal gasification and gas fuel combustion, and the specific technical contents, details, steps and methods are not detailed herein.

Embodiment 3:

airtight coal material is carried and cloth coal system (2), airtight coal material is carried and is arranged coal system and includes: the burner has a closed structure with the function of isolating air at the coal input end and the function of a burner which is basically the same as or similar to that of a coal powder burner in the existing pulverized coal boiler. The gasification agent generation and gas distribution system (1) utilizes internal or external energy to generate medium-high temperature oxygen-lacking oxidant with effectively controllable temperature, flow, component proportion and the like. Coal materials (coal powder) and medium-high temperature oxygen-lacking oxidant from a gasifying agent generating and gas distributing system (1) are fully mixed in a mixing pipe section and are sprayed out to a coal gas space (3) through a coal powder burner under the action of gas power; and simultaneously, the coal gasification agent is fully mixed with primary, secondary or even multiple medium-high temperature oxygen-lacking oxidant sprayed from the burner and the periphery to generate high-efficiency coal gasification reaction and generate hot coal gas. The coal gasification-gas boiler and the coal energy utilization system have wide applicable coal types and coal quality range and can be weak-viscosity and non-sticky coal; low, medium and high calorific value coals; the coal material is pulverized coal.

The coal powder is rapidly gasified under the action of a medium-high temperature oxygen-lacking oxidant to generate hot coal gas, the hot coal gas is collected, buffered and stabilized in a coal gas space (3), enters a combustion space (5) through a coal gas grid and a gas distribution system (4), is mixed with air blown in by a primary air gas distribution system (6.1) and a secondary air gas distribution system (6.2) of a blowing and gas distribution system, is combusted and releases heat energy, and high-temperature tail gas is generated; it is produced into steam through a heat exchange system, and the steam is discharged after being purified.

The closed coal material conveying and coal distributing system (2) effectively realizes that the coal powder is premixed with the medium-high temperature oxygen-depleted oxidant generated by the gasifying agent and the air distributing system (1) under the condition of being isolated from the outside air, is sprayed out by a coal powder burner and is mixed with the once, twice or even multiple times of medium-high temperature oxygen-depleted oxidant sprayed out simultaneously, so that high-efficiency coal gasification reaction is generated.

The coal gasification-gas boiler system and the coal energy utilization system adopt the implementation method which is the same as or similar to the existing coal powder boiler technical equipment and technical system, and the technology and the method which can be effectively implemented by professional engineering technicians in the technical fields of coal gasification and gas fuel combustion, and the specific technical contents, details, steps and methods are not detailed herein.

In addition, the medium-high temperature oxygen-depleted oxidant generation device and method in the coal gasification and energy utilization systems and coal gasification and energy utilization methods are applied to the prior combustion technical field, the prior art and equipment for generating medium-high temperature oxygen-depleted flue gas can be utilized, professional engineering technicians in the field can effectively implement the method, and detailed description is omitted.

The invention has the following advantages:

1) the invention adopts the medium-high temperature oxygen-lacking oxidant mainly comprising carbon dioxide, water (water vapor) and nitrogen, so that the coal material can be gasified cleanly and efficiently in a high-temperature environment, and hot coal gas is generated and directly combusted and utilized; the direct combustion utilization of the hot coal gas obviously improves the energy efficiency and the heat energy utilization rate of the system.

2) Hot gas enters a combustion space through a gas space and a gas grid, and gas fuel is fully combusted under the condition of low excess air coefficient under the action of primary air and secondary air, so that heat energy is efficiently released, and the discharge amount of high-temperature tail gas is reduced; the heat energy utilization rate of the system is obviously improved, and the pollution and emission reduction treatment capacity of tail gas is reduced.

3) The coal gasification-gas boiler and coal energy clean utilization system is suitable for high-efficiency gasification and energy utilization of coal with various coal types and different coal qualities, and particularly utilizes low-calorific-value coal resources such as lignite, coal gangue and the like in a clean and efficient manner.

4) Due to the unique composition and design of the coal gasification-gas boiler, the air blast volume and the air speed of the coal gasification-gas boiler are lower than those of a corresponding coal-fired boiler system, such as a circulating fluidized bed boiler system, the emission amount of fly ash and particulate matters is obviously lower than that of the existing coal-fired boiler system with the same scale, and the burden and the cost of particulate matter emission reduction are reduced.

5) The high-efficiency coal gasification-gas boiler system and the coal energy clean utilization system are not limited by application scale, can be applied to medium-sized to large-sized and ultra-large-sized heat energy boiler systems and heat energy power generation systems, and realize the clean and high-efficiency utilization of large-scale coal energy.

6) The conventional coal-fired boiler system can be upgraded into the coal gasification-gas boiler system and the coal energy utilization system through technical improvement, and the improvement cost of the energy conservation and emission reduction technology of the conventional coal-fired boiler system is effectively reduced.

Those not described in detail in this specification are within the skill of the art.

Reference documents: (e.g., patents/papers/standards)

1. The circulating fluidized bed boiler technology is 1000 questions: china Power Press, 2016-06-01.

2. The technology of the pulverized coal industrial boiler is effectively popularized and applied, namely, a phoenix net 2014-02-18.

Claims

1. An efficient coal gasification-gas boiler system and a coal energy utilization system are disclosed, which utilize medium-high temperature oxygen-lacking oxidant to realize efficient coal gasification of coal material in a hearth to generate hot coal gas, and then complete heat energy release and exchange in a coal gas combustion mode; the peripheral equipment and the configuration of the general equipment or parts are the same as or similar to that of the existing coal-fired boilers with various main types and scales, and the working temperature range and the function of the heat energy absorption and exchange equipment or the steam-water system are also the same as or similar to that of the existing equipment; the method is characterized in that:

2. The high-efficiency coal gasification-gas boiler system and the coal energy utilization system according to claim 1, wherein: the system comprises a gasification agent generating and distributing system (1), a gasification agent generating device which utilizes internal or external energy to generate medium-high temperature oxygen-depleted gas and effectively controls the medium-high temperature oxygen-depleted gas according to the operation requirement and the gasification process requirement of a boiler system, and a gasification agent distributing device which is composed of a gasification agent transmission and distribution structure and an exhaust outlet and provides the function of mixing the medium-high temperature oxygen-depleted gas and coal or carrying the coal.

3. The high-efficiency coal gasification-gas boiler system and the coal energy utilization system according to claim 1, wherein: the closed coal material conveying and distributing system (2) provides a spatial structure and hydrodynamic conditions for the effective and sufficient contact coal gasification reaction of the coal material and a medium-high temperature oxygen-lacking oxidant generated by the gasification agent generation and distribution system (1), realizes that the coal material enters a boiler in an equipment structure comprising a fixed bed, a chain grate, a circulating fluidized bed, a pulverized coal injection material or a combination thereof and a coal material conveying and distributing mode, and generates hot coal gas under the action of the medium-high temperature oxygen-lacking oxidant.

4. The high-efficiency coal gasification-gas boiler system and the coal energy utilization system according to claim 1, wherein: the closed coal conveying and distributing system (2) is used for conveying coal comprising coal blocks, coal particles or coal dust, and effectively and fully contacting with a medium-high temperature oxygen-lacking oxidant generated by a gasification agent generation and gas distribution system (1) under the hydrodynamic conditions and reaction time, so that equipment structures formed by a fixed bed, a chain grate, a circulating fluidized bed and coal dust injection or a combination of the fixed bed, the chain grate, the circulating fluidized bed and the coal dust injection and a coal conveying and distributing mode are realized, and the high-efficiency coal gasification reaction is completed.

5. The high-efficiency coal gasification-gas boiler system and the coal energy utilization system according to claim 1, wherein: the gasification device is formed by combining and integrating a gasification agent generation and gas distribution system (1) and a closed coal conveying and coal distribution system (2), provides a space structure and a fluid dynamics condition for a medium-high temperature oxygen-lacking oxidant from the gasification agent generation and gas distribution system (1) to effectively enter the closed coal conveying and coal distribution system (2), and forms a gasification condition for the medium-high temperature oxygen-lacking oxidant to fully contact with coal and generate coal gasification reaction, so that the coal is subjected to high-efficiency coal gasification reaction.

6. The high-efficiency coal gasification-gas boiler system and the coal energy utilization system according to claim 1, wherein:

the system comprises a gasification agent generation and gas distribution system (1), a gasification agent generation device and a gasification agent gas distribution device, wherein the gasification agent generation and gas distribution system (1) is composed of a gasification agent generation device which can effectively generate and control medium-high temperature hypoxic flue gas by utilizing parameters such as temperature, flow and component proportion generated by internal or external energy according to the operation requirement of a boiler system and the gasification process requirement, and the gasification agent gas distribution device has the functions of mixing a gasification agent with coal materials or carrying and conveying the coal materials;

the closed coal conveying and distributing system (2) effectively realizes that the coal comprising coal blocks, coal particles or coal dust is added and conveyed into a coal gasification-gas boiler system, and is combined with a gasifying agent generation and distributing system (1) to jointly provide a spatial structure, a fluid dynamic condition and a coal gasification reaction gasification condition for effectively contacting and mixing a medium-high temperature spent oxidizing agent and the coal;

a gas space (3) for collecting, buffering and stabilizing gas generated by the continuous coal gasification;

the gas grid and gas distribution system (4) is used for maintaining the incompletely gasified coal particles to stay in the space mixed with the gasifying agent, so that the gasification rate and the coal utilization rate are improved; the particle emission of tail gas is reduced by blocking particles in the coal gas; absorbing and storing partial heat energy generated by gas combustion, and establishing and stabilizing a gas combustion environment; the coal gas distribution which is beneficial to fully mixing hot coal gas and blast air is formed, and clean and efficient coal gas combustion of a coal gasification-gas boiler system is realized;

the combustion space (5) is used for providing sufficient mixing of hot coal gas and air, cleaning the space required by high-efficiency combustion, providing space for absorbing and converting the radiant heat energy exchanger and improving the energy utilization efficiency;

a primary air distribution system (6.1) and a secondary air distribution system (6.2) of the air blast and distribution system can be adjusted according to the operation requirement of the coal gasification-gas boiler system, and the combustion state of hot coal gas, the temperature of tail gas and the quantity of the tail gas are controlled by primary air and secondary air of a transmission pipeline and an exhaust gas distribution nozzle; air, oxygen-enriched air or pure oxygen can be used as an oxidant according to the operation requirement of a boiler system;

an ash space (7) which provides a space and structural conditions for cooling and collecting ash generated after the coal is gasified;

the closed slag discharging system (8) effectively discharges ash slag generated after coal gasification out of the coal gasification-gas boiler system in a continuous or intermittent mode through a closed slag discharging device with a material conveying function;

the heat exchange or steam-water system of a coal gasification-gas fired boiler system is a general heat exchange equipment component or equipment system that passes thermal energy released from the combustion of hot coal gas produced by the gasification of coal feedstock through radiant heat exchangers, such as: the system comprises a water-cooled wall, an economizer, a superheater, an air preheater and the like, and is used for exchanging heat energy to generate required steam and hot water so as to realize the recycling of the heat energy.

7. An efficient coal gasification-gas fired boiler system and coal energy utilization system as claimed in claim 1, comprising: the coal gasification-gas fired boiler system according to any of claims 1, 2, 3, 4, 5 or 6, wherein the gasifying agent generation and gas distribution system (1) is connected with the closed coal conveying and coal distribution system (2) to provide medium-high temperature oxygen-depleted oxidant for the coal; the closed coal material conveying and distributing system (2) is connected with the coal gas space (3) to provide coal material for coal gasification; the gas space (3) is connected with the gas grid and the gas distribution system (4) to provide a hot gas buffer space; the gas grid and the gas distribution system (4) are connected with the combustion space (5) to provide gas needed by dust suppression, heat storage and combustion of the gas; the combustion space (5) is connected with a primary air distribution system (6.1) and a secondary air distribution system (6.2) of the blast and air distribution system, and provides space and oxidant such as air, oxygen enrichment or pure oxygen for clean combustion of hot gas; the heat exchange or steam-water system of the boiler is connected with the combustion space (5) to convert the high-temperature heat energy generated and released by the combustion of the coal gas into steam; the ash space (7) is connected with the gasification agent generation and gas distribution system (1) and used for collecting ash generated after the coal material is gasified; the ash space (7) is connected with a closed slag discharging system (8) and used for collecting and discharging ash under a closed condition.

8. An efficient coal gasification-gas fired boiler system and coal energy utilization system as claimed in any one of claims 1, 2, 3, 4, 5, 6 or 7, wherein: the prepared coal material in the state of coal blocks, coal particles or pulverized coal material continuously or intermittently enters a coal gasification-gas boiler system in a proper amount through a closed coal material conveying and coal distributing system (2) in a coal material conveying and coal distributing mode comprising a fixed bed, a chain grate, a circulating fluidized bed, pulverized coal injection or a combination of the fixed bed, the chain grate, the circulating fluidized bed and the pulverized coal injection, and directly contacts and mixes with a medium-high temperature oxygen-lack oxidant generated by a gas distributing system (1) to enable the coal material to generate high-efficiency coal gasification reaction under the action of the medium-high temperature oxygen-lack oxidant to generate hot coal gas;

hot coal gas enters a combustion space (5) after passing through a coal gas space (3) and a coal gas grid and gas distribution system (4), and is combusted with air or oxygen-enriched or pure oxygen from a primary air gas distribution system (6.1) and a secondary air gas distribution system (6.2) of a blast and gas distribution system to release heat energy and generate radiant heat and high-temperature tail gas;

the radiant heat and the high-temperature tail gas pass through a heat exchange or steam-water system formed by common heat exchange equipment parts or equipment systems such as a water wall, a radiant heat exchanger, an economizer, a superheater, an air preheater and the like, so that the steam and the heat energy required by heat energy exchange are recycled;

the gasification agent generation and gas distribution system (1) can utilize an internal or external fuel source to generate hypoxic flue gas with adjustable and controllable temperature, flow rate, component proportion and the like according to coal gasification requirements, and the hypoxic flue gas is used as a medium-high temperature hypoxic oxidant;

the medium-high temperature oxygen-lacking oxidant which can effectively control parameters such as temperature and the like generated by the gasifying agent generation and gas distribution system (1) is directly contacted and mixed with the coal material conveyed by the closed coal material conveying and coal distribution system (2) to generate a coal gasification reaction;

the ash generated by the coal gasification reaction continuously carried out in the coal gasification-gas boiler system is collected in an ash space (7) and discharged out of the coal gasification-gas boiler system through a closed slag discharging system (8).