CN204240384U - Superheat steam drying powder process type coal generating system - Google Patents

Abstract

The utility model provides a superheated steam drying pulverization type coal-fired power generation system, which is used to drive a generator to generate electricity after burning raw coal, including: a boiler unit, including: a pulverization subsystem, a boiler host subsystem, and an air and powder feeding system. Subsystem and exhaust steam water recovery subsystem; and steam turbine unit, wherein the pulverization subsystem includes: steam powder generation and drying device, steam powder separation device, and desiccant generation device for generating desiccant, and the exhaust steam heater utilizes the extraction of steam turbine The heat released by the condensation of the steam heats the exhaust steam in the exhaust steam heater to form superheated steam. The exhaust steam water recovery subsystem includes: the exhaust steam water recovery device that uses the low-temperature condensed water of the steam turbine unit and the ambient cold air to condense and recover a part of the exhaust steam , the ambient cold air is preheated by the exhaust steam to obtain warm air, and the air preheater heats a part of the warm air to obtain hot air, and a part of the hot air is mixed with the other part of the warm air in the primary air mixing chamber and enters the air powder as primary air mixer.

Description

Coal-fired power generation system with superheated steam drying and pulverization

technical field

The utility model relates to the field of coal-fired power generation, in particular to a coal-fired power generation system of boiler air supply, superheated steam drying pulverization, coal water recovery technology and superheated steam drying pulverization utilizing steam extraction heat of a steam turbine.

Background technique

my country is a country rich in coal but lacking in oil and gas. Coal has always been in the core dominant position in my country's energy supply. For a long time to come, the energy structure dominated by coal will continue in my country. Because coal-fired power stations have the characteristics of large-scale concentrated use of coal, which is conducive to efficient and clean utilization of coal, coal is mainly used for power generation at home and abroad. At present in my country, 55% of the total coal output is used for coal-fired thermal power generation. In terms of power structure, thermal power generation is the main power generation method in my country. About 80% of my country's power supply comes from thermal power units. At present, my country's new power stations are still dominated by coal-fired power stations, and the proportion of thermal coal in total coal output is growing rapidly. However, coal-fired power generation also emits a large amount of pollutants while producing electricity, including SO ₂ , soot, NO _X and CO ₂ ; moreover, there is still a large gap between the net power generation efficiency of coal-fired power plants in China and developed countries . Therefore, further improving energy utilization efficiency so as to reduce both energy consumption and pollutant emissions has become an important and urgent task for my country's electric power industry and even the entire national economy to achieve sustainable development.

In recent years, with the rapid rise of thermal coal prices and the gradual decline in the proportion of high-quality coal reserves in total coal reserves, the use of high-moisture lignite to generate electricity has become a prominent issue of great concern to the power industry. Lignite accounts for about 40% of the world's total coal reserves in the world. In my country, the lignite reserves are 290 billion tons, accounting for about 16% of the total domestic coal reserves. Lignite is the coal with the lowest degree of coalification. It has the characteristics of high moisture, high volatile matter, low calorific value, and easy weathering and spontaneous combustion in the air. Therefore, it is difficult to store and not suitable for long-distance transportation. 3/4 of my country's lignite is distributed in Inner Mongolia and Northeast China. These lignites have a total moisture content of 25-40%, which belongs to aged lignite; the rest of the lignite is mainly distributed in Yunnan. Young lignite; while foreign countries such as Australia, Germany, Serbia, Indonesia and other countries have higher moisture content, up to 70%.

At present, the main way to utilize lignite is to generate electricity through combustion in pithead power stations. Lignite and bituminous coal boilers mostly use direct blowing pulverization systems, and generally use a mixture of furnace smoke and hot air or hot air as the desiccant in the pulverization system; lean coal and anthracite mostly use intermediate The silo-type pulverizing system generally uses hot air as the desiccant of the pulverizing system. However, compared with conventional bituminous coal boilers, these lignite boilers have low thermal efficiency, large volume and high price, and large greenhouse gas emissions. Moreover, for high-moisture lignite, the use of direct blowing pulverization system makes the primary air of the boiler contain a large amount of inert media such as furnace smoke and water vapor, and the temperature of the furnace is low, which makes the high-moisture lignite have prominent combustion instability problems, resulting in boiler It is difficult to operate safely and reliably, which seriously restricts the effective utilization of high-moisture lignite at home and abroad. At the same time, due to the high reactivity of lignite, lignite coal powder is flammable and explosive, and the combustion and explosion problems of lignite pulverization system are also a prominent problem that has plagued the safe and reliable operation of lignite units for a long time.

In addition, the predicted coal reserves of the "Zhundong Coalfield" located in the eastern Junggar Basin, Xinjiang, my country reach 390 billion tons, making it the largest integrated coalfield in China. Zhundong coal has higher heat release than lignite, and other coal characteristics are similar to lignite, and it also has the characteristics of high moisture (22-32%), high volatile matter, low ash melting point, low abrasiveness and easy spontaneous combustion. At present, the large-scale power plant boilers developed for Zhundong Coal in the industry all adopt the direct blowing pulverizing system. Therefore, in order to ensure the drying output of the pulverizing system and the stable combustion in the furnace, the boilers adopt a high hot air temperature and primary air rate. As a result, the exhaust gas temperature of these Zhundong coal-fired boilers is generally high (the exhaust gas temperature is generally above 140°C), which correspondingly leads to low boiler thermal efficiency and unit power generation efficiency; moreover, the excessively high primary air rate This makes the organization of low NO _X combustion in the furnace more difficult, that is, the content of NO _X in the flue gas at the furnace outlet is relatively large, which significantly increases the pressure and cost of the subsequent flue gas denitrification of the boiler.

Furthermore, in boilers burning high-moisture coal, a large amount of heat released by the combustion of combustible substances in coal is consumed by the evaporation of water in coal into water vapor. Since the water is finally discharged from the boiler in the form of water vapor, the fuel is actually A considerable portion of the heat release is wasted. Therefore, the existing high-moisture coal-fired boilers often show a huge amount of coal combustion, and the pollutant emissions per unit of power generation are also significantly higher. If the thermal efficiency of the boiler is calculated based on the high calorific value that represents the actual heat released by the fuel, the thermal efficiency of the high-moisture coal-fired boiler is significantly lower than that of the general low-moisture coal-fired boiler.

In recent years, the thermal power industry has paid extensive attention to further improving the power generation efficiency of power plants through the deep utilization of boiler exhaust heat. The typical way is to arrange low-pressure economizers in the boiler exhaust flue, and use the exhaust heat to heat the low-temperature unit condensate, thereby Reduce the extraction steam of the low-pressure heater to achieve the purpose of improving the efficiency of the power plant. Obviously, using the low temperature of condensate water in units to recover waste heat is one of the effective ways for power plants to improve power generation efficiency and obtain energy-saving and emission-reduction benefits. However, due to the low heat transfer coefficient of flue gas and the exchange The thermal temperature difference is small, so that the low-pressure economizer that heats condensed water through the flue gas is bulky, the investment recovery period is long, and it is difficult to arrange in the power plant.

On the other hand, my country's main lignite-producing areas (eastern Inner Mongolia) and Zhundong coal-producing areas (Xinjiang) are extremely water-scarce areas. Since thermal power units consume a lot of water, the lack of water resources has become the primary constraint factor for the construction of power bases in these areas to develop and utilize lignite and Zhundong coal resources. However, as we all know, the pulverizing system is also a drying system. In order to ensure the stable combustion of the pulverized coal gas flow into the furnace, the pulverizing system is required to dry the raw coal to a very low moisture content of the pulverized coal. Power plant boilers burn a huge amount of coal, so a large amount of water in the coal evaporates into water vapor in the pulverizing system and enters the furnace with the coal powder, becoming one of the components of the boiler flue gas. In addition, thermal power plants are large industrial water users, while most of my country's lignite production areas (such as the eastern part of Inner Mongolia) are severely water-scarce areas, and the lack of water resources has become an important restrictive factor affecting the construction of pithead power bases. Therefore, if the moisture in the coal can be recovered, it will have very important ecological protection significance for the utilization of lignite and Zhundong coal in my country. However, due to the dilution of a large amount of dry flue gas (mainly N ₂ , CO ₂ and excess dry air) in the furnace, the moisture content and water dew point temperature of the boiler exhaust gas are very low, which makes it possible to recover the flue gas by cooling the boiler exhaust gas moisture becomes very difficult. Taking an in-service 600MW unit burning lignite with 40% total moisture as an example, the exhaust gas output of the boiler is 2800t/h. Although the exhaust gas contains 270t/h moisture, the dew point of the exhaust gas water is only 53°C (the water vapor volume fraction is 15 %). It can be seen that due to the huge amount of dry flue gas and the low water dew point, the recovery of moisture in the exhaust gas requires a huge flue gas cooling heat exchanger and a large amount of cooling medium with a sufficiently low temperature, which makes the recovery of moisture from the exhaust gas and the latent heat of water vapor condensation extremely difficult. Difficult, so far there is no engineering application to achieve flue gas water recovery and heat recovery by cooling the exhaust gas of power plant boilers.

Utility model content

The utility model is developed to solve the above-mentioned problems, and the purpose is to provide a superheated steam drying pulverizing coal-fired coal-fired system which has outstanding water recovery benefits and energy-saving benefits, and can also ensure the safe operation of the pulverizing system and higher coal-burning efficiency. Power system.

The utility model provides a superheated steam drying pulverizing type coal-fired power generation system, which is used to burn raw coal to drive a generator to generate electricity. The feed water is heated to obtain high-temperature and high-pressure steam, including: pulverization subsystem, boiler host subsystem, air supply and powder supply subsystem, and spent steam and water recovery subsystem; and a steam turbine unit, which uses high-temperature and high-pressure steam to do work to drive the generator to generate electricity. It includes a water supply pipe for delivering feed water, a steam delivery pipe for delivering high-temperature and high-pressure steam, and a steam turbine. The steam powder generation and drying device of the powder mixture, which separates the steam powder mixture to obtain coal powder and exhaust steam (exhaust steam: generally, the low-temperature gas discharged from the airflow drying system is called exhaust gas. According to this custom, in the boiler pulverization system The gas discharged from the outlet of the coal mill is also often referred to as depleted gas. Because the pulverizing system in the utility model uses water vapor as the desiccant and powder delivery medium, the water vapor in the steam-powder mixture at the outlet of the coal mill is depleted. steam) steam powder separation device, and desiccant generating device for generating desiccant, the main boiler subsystem is used to heat the feed water into high-temperature and high-pressure steam, including: the furnace, the flue in the furnace connected to the outlet of the furnace, located in the furnace The pulverized coal burner at the entrance position, the air supply and powder delivery subsystem includes: a powder feeder connected with the steam powder separation device for conveying coal powder, an air powder mixer connected with the powder feeder, and an air powder mixer The connected primary air mixing chamber, the air preheater located at the tail of the flue in the furnace, and the blower used to provide cold air, the spent steam water recovery subsystem includes: connected to the steam turbine unit and connected to the blower unit to utilize the low temperature of the steam turbine unit Condensed water and cold air condense and recover a part of the exhaust steam. The steam powder separation device includes: a coal dust collector that separates the steam powder mixture to obtain coal powder and exhaust steam. The desiccant generation device includes: The powder collector is connected to the exhaust steam pipeline for conveying exhaust steam, the exhaust steam circulation pipeline connected to another part of the exhaust steam pipeline for conveying exhaust steam, and the exhaust steam circulation pipeline connected to the exhaust steam circulation pipeline. Steam is heated to form superheated steam as a desiccant exhaust steam heater, and a superheated steam pipeline that transports the desiccant to the steam powder generation and drying device for circulation. The exhaust steam heater utilizes the condensation heat of the extraction steam of the steam turbine The exhaust steam in the exhaust steam heater is heated to form superheated steam, and the powder feeder is used to deliver coal powder to the air-powder mixer, and the air-powder mixer mixes the primary air and coal powder from the air supply and powder delivery subsystem to obtain Air-powder mixture, the exhaust steam in the exhaust steam water recovery device is condensed by the low-temperature condensate water of the steam turbine unit and the cold air provided by the blower to become condensate water, and the cold air is preheated by the heat of the exhaust steam in the exhaust steam water recovery device to obtain warm air, and the air is preheated The device heats a part of the warm air to obtain hot air, and a part of the hot air is mixed with the other part of the warm air in the primary air mixing chamber and enters the air-powder mixer as primary air, and the other part of the hot air directly enters the pulverized coal combustion as secondary air in the device , The pulverized coal burner burns the pulverized coal in the air-powder mixture, and the pulverized coal, primary air and secondary air burn in the furnace to generate flue gas.

In the superheated steam drying pulverization type coal-fired power generation system provided by the utility model, it can have such features, and also includes: a flue gas purification subsystem, connected with the tail outlet of the flue in the furnace, including: sequentially connected dust removal device, induced draft fan, desulfurization device, chimney.

In the superheated steam drying pulverization type coal-fired power generation system provided by the utility model, it can also have such a feature: wherein, the spent steam water recovery device includes: a exhausted steam output pipeline connected to the exhausted steam pipeline, and a exhausted steam output pipeline It is connected to the condenser that condenses the exhaust steam into condensate by using low-temperature condensate and cold air, the water collector that stores and recovers the condensate, and the exhaust steam bypass pipeline that is connected with the exhaust steam output pipeline to directly introduce the exhaust steam into the desulfurization device The condenser includes a cold water inlet pipe connected to the steam turbine unit and a cold water outlet pipe connected to the steam turbine unit. The low-temperature condensed water flows into the condenser through the cold water inlet pipe to condense the exhaust steam. After heating, it flows back to the steam turbine unit through the cold water outlet pipe.

In the superheated steam drying pulverization type coal-fired power generation system provided by the utility model, it can also have such a feature: wherein, the spent steam water recovery subsystem also includes: a residual gas delivery device for transporting the residual gas output from the condenser , the residual gas conveying device includes: a residual gas pipeline connected with the outlet of the condenser for transporting the residual gas into the primary air mixing chamber, and a residual gas pipeline connected with the residual gas pipeline and directly introducing the residual gas into the desulfurization device Bypass piping.

In the superheated steam drying pulverization type coal-fired power generation system provided by the utility model, it can also have such a feature: wherein, the steam powder generation and drying device also includes: a coal mill for grinding and drying raw coal to form a steam powder mixture , and connected to the outlet of the coal mill for separating the coarse powder in the steam-powder mixture and sending the coarse powder back to the coarse powder separator in the coal mill.

In the superheated steam drying pulverization type coal-fired power generation system provided by the utility model, it can also have such a feature: wherein, the steam powder generating and drying device also includes: the outlet is connected with the inlet of the coal mill for pre-processing the raw coal Dry raw coal pre-drying pipe and steam delivery pipe, the inlet of the raw coal pre-drying pipe is connected to the superheated steam pipe through the steam delivery pipe, and the superheated steam is used as a pre-drying agent to pre-dry the raw coal in the raw coal pre-drying pipe.

In the superheated steam drying pulverization type coal-fired power generation system provided by the utility model, it can also have such a feature: wherein, the exhaust steam heater includes: a steam extraction pipeline connected with a steam turbine unit for transporting extraction steam, for The drain pipeline that transports the drain formed after the extraction steam condenses and releases heat in the exhaust steam heater and returns to the steam turbine unit.

In the superheated steam drying pulverization type coal-fired power generation system provided by the utility model, it can also have such a feature: wherein, the pulverization subsystem also includes: a gas delivery pipe connected with the exhaust steam circulation pipeline for transporting gas, and a device The control valve on the gas pipeline is used to control the opening and closing of the gas pipeline. The control valve controls the gas pipeline to deliver gas to the exhaust steam circulation pipeline. The gas is heated and used as a desiccant. After the preset time, the control valve controls the gas pipeline to stop flowing The exhaust steam circulation pipeline transports gas.

In the superheated steam drying pulverization type coal-fired power generation system provided by the utility model, it may also have such a feature: wherein, the gas is any one of air or industrial inert gas.

Function and effect of utility model

In the superheated steam drying pulverizing coal-fired power generation system of the utility model, because the pulverizing subsystem uses superheated steam as the desiccant and ventilation medium of the pulverizing subsystem, and the superheated steam is generated from steam powder to dry the raw coal in the device The circulating exhaust steam formed by the evaporation of water in the coal is formed by heating with the condensation and heat release of the steam extracted by the steam turbine. In addition to the circulating exhaust steam of internal circulation work, another part of exhaust steam produced by the continuous evaporation of moisture in the raw coal in the pulverization subsystem is recovered by the exhaust steam water recovery subsystem.

The utility model uses superheated steam as the desiccant of the pulverizing subsystem, so that the whole pulverizing subsystem operates under a completely inert atmosphere, ensuring the safe and reliable operation of pulverizing coal with high volatile content such as lignite and Zhundong coal, and solving the problem of The combustion and explosion problems of the pulverizing system that have long plagued the safe and reliable operation of lignite and Zhundong coal units have been solved. In addition, the internal generation and recycling of the inert powder-making desiccant is realized. The powder-making process does not require additional steam and nitrogen production systems, nor does it need to consume flue gas, hot air and other media, making the powder-making process safe and reliable. , and the process is simple and efficient. Moreover, superheated steam is used as the desiccant in the pulverizing system, which improves the problem of poor particle size uniformity of pulverized coal particles caused by a large number of coal particles bursting in the process of furnace smoke drying and hot air drying, thereby helping to improve the combustion performance of pulverized coal. , Improve the efficiency of pulverized coal combustion.

The superheated steam in the utility model is obtained by heating the exhaust steam by steam extraction of the steam turbine, that is, the heat source in the exhaust steam heater comes from the condensation and heat release of the steam extraction steam of the steam turbine unit, so that the condensation heat release of the steam extraction can be effectively used for coal-fired pulverization The dry output of the system means that the waste heat of condensation of the steam in the steam turbine unit is effectively utilized by the boiler system, which greatly reduces the loss of the cold source of the thermal cycle of the steam turbine. Therefore, the application of this technical solution can also greatly improve the efficiency of the power plant, and has outstanding energy-saving benefits.

The utility model completely uses the water vapor generated inside the pulverizing sub-system as the desiccant and the pulverizing medium, which makes the waste heat recovery and water recovery of the pulverizing waste steam that is almost pure water vapor very easy. Through the waste heat recovery of waste steam from pulverization, the energy utilization efficiency of boilers and coal-fired energy systems can be further improved; moreover, the recovery and reuse of a large amount of water resources achieved by the waste steam recovery device while realizing waste heat recovery is even more beneficial to Coal-rich and water-scarce areas have immeasurable environmental significance.

The cold air delivered by the blower is used as a cooling medium in the exhaust steam recovery device to cool the exhaust steam, the cold air is preheated to form warm air, and the warm air finally enters the boiler for combustion, so that a large amount of latent heat of condensation of the exhaust steam can be effectively utilized by the boiler, thereby enabling The thermal efficiency of the boiler is greatly improved, making it possible for the thermal efficiency of the coal-fired power plant boiler to exceed 100% calculated based on the low calorific value of coal-fired. On the premise of ensuring the best warm air temperature, when the boiler air supply cooling alone is not enough to fully recover the exhaust heat, the utility model further uses the low-temperature condensed water from the steam turbine unit as a cooling medium in the exhaust steam recovery device to cool the exhaust steam. , the low-temperature condensate is heated to a certain temperature and returned to the steam turbine unit to reduce the steam extraction of the low-pressure heater, so that the latent heat of condensation of the exhausted steam can be effectively used by the thermal system of the steam turbine unit, thereby further improving the power generation efficiency of the power plant. Through the combined application of air-cooled and water-cooled waste heat recovery methods, the recovery effect of exhausted steam and water can be fully guaranteed, and through the optimal distribution of air-cooled and water-cooled heat, the power generation efficiency of the power generation system can be maximized, and the load of the power generation system can be changed The adjustment during operation is more flexible and convenient. In addition, compared with the existing low-pressure economizer heated by flue gas, the volume and investment cost of the water-cooled condenser in the utility model will be greatly reduced.

The utility model separates the steam-powder mixture through the coal powder collector to obtain low-moisture coal powder, so that the quality of coal combustion can be greatly improved. The dried and upgraded pulverized coal is fed into the boiler by the air at a certain temperature for combustion, and there will be no problems such as low temperature in the furnace, unstable combustion, low _NOx combustion organization, and other problems. At the same time, the use of hot air to feed the powder greatly reduces the content of inert gas in the primary air, thus reducing the heat of the pulverized coal flow and increasing the oxygen concentration in the primary air. The result of the combined effect is not only to improve the stable combustion performance and combustion efficiency of the pulverized coal flow, but also to make the low NOx combustion organization of the pulverized coal flow more convenient, so as to achieve clean, efficient and stable combustion. Moreover, the dried and upgraded coal powder is sent to the boiler for combustion by the primary air with a certain temperature in the air supply subsystem, and the moisture in the raw coal evaporated from the pulverization subsystem is no longer accompanied by the powder delivery medium. Entering the boiler, the amount of smoke exhausted by the boiler is greatly reduced, and the temperature of the corresponding boiler exhaust smoke is also reduced. Finally, the heat loss of the boiler exhaust smoke is greatly reduced, and the thermal efficiency of the boiler is significantly improved.

Therefore, the superheated steam drying pulverizing coal-fired power generation system provided by the utility model has outstanding water recovery benefits and energy-saving benefits.

Description of drawings

Fig. 1 is the structural block diagram of superheated steam drying pulverizing type coal-fired power generation system in the utility model embodiment;

Fig. 2 is the structural block diagram of boiler unit in the utility model embodiment;

Fig. 3 is a schematic structural view of a superheated steam drying pulverizing coal-fired power generation system in an embodiment of the present invention;

Fig. 4 is the flowchart of the superheated steam drying pulverizing type coal-fired power generation system in the embodiment of the utility model;

Fig. 5 is the block diagram of air supply and powder delivery subsystem in the utility model embodiment; And

Fig. 6 is a block diagram of the pulverizing subsystem in the embodiment of the utility model.

Detailed ways

In order to make the technical means, creative features, goals and effects of this utility model easy to understand, the following examples will describe in detail the utility model related to superheated steam drying pulverization coal-fired power generation system in conjunction with the accompanying drawings and examples.

Fig. 1 is a structural block diagram of a superheated steam drying pulverizing coal-fired power generation system in an embodiment of the utility model.

As shown in FIG. 1 , the superheated steam drying pulverizing coal-fired power generation system 100 includes: a boiler unit 501 , a steam turbine unit 502 , and a generator unit 503 .

The heat generated by the combustion of raw coal in the boiler unit 501 heats the water to form high-temperature and high-pressure steam that enters the steam turbine unit 502 to do work, and then drives the generator unit 503 to generate electricity.

Fig. 2 is a structural block diagram of the boiler unit in the embodiment of the utility model.

As shown in FIG. 2 , the boiler unit 501 includes: a pulverizing subsystem 401 , a boiler host subsystem 402 , an air and powder feeding subsystem 403 , a spent steam water recovery subsystem 404 , and a flue gas purification subsystem 405 .

The air supply and powder delivery subsystem 403 and the spent steam and water recovery subsystem 404 process the cold air 2 to form primary air and secondary air respectively. Among them, the primary air and pulverization subsystem 401 grind the raw coal 1 to form pulverized coal at a certain rate. After being mixed in proportion, it is sent to the main boiler subsystem 402, and the secondary air from the air supply subsystem 403 directly enters the boiler main subsystem 402 to participate in combustion, and a part of exhaust steam separated from the pulverizing subsystem 401 is sent to The exhausted steam and water recovery subsystem 404 performs water recovery, and the exhausted steam is condensed into condensed water by the low-temperature condensed water in the steam turbine unit 502 and the cold air of the air supply and powder delivery subsystem 403, and is recovered for reuse, and the heat in the exhausted steam (i.e., Water vapor condensation heat release) preheats the cold wind 2, so that the heat in the water vapor is fully utilized. The other part of the exhaust steam is heated by the high-temperature flue gas of the main boiler subsystem 402 to become superheated steam, and then enters the pulverizing subsystem 401 as a desiccant. The flue gas from the boiler host subsystem 402 finally enters the flue gas purification subsystem 405 to be purified and then discharged to the atmosphere.

Fig. 3 is a structural schematic diagram of a superheated steam drying pulverization type coal-fired power generation system in an embodiment of the utility model.

As shown in FIG. 3 , the steam turbine unit 502 utilizes the heat energy generated in the boiler unit 501 to heat feed water to obtain high-temperature and high-pressure steam, thereby driving the generator unit 503 to generate electricity. The steam turbine unit 502 includes a water supply pipe 61, a steam delivery pipe 62, a steam turbine 60 and a steam extraction heat recovery system (not shown in the figure). Generator set 503 includes generator 70 . The generator 70 is connected to the steam turbine 60 , and the generator 70 generates electricity under the drive of the steam turbine 60 .

The pulverization subsystem 401 includes: a steam powder generating and drying device, a desiccant generating device, and a steam powder separating device. The steam powder generation and drying device is used to grind the raw coal 1 and use the desiccant generated by the desiccant generation device to dry the raw coal 1 to form a steam powder mixture. The gas powder mixture enters the steam powder separation device and is separated to obtain coal powder and exhaust gas. The obtained pulverized coal can be stored or directly sent to the boiler main engine subsystem 402 for combustion. Most of the obtained waste steam is used as the desiccant and ventilation medium of the pulverization subsystem 401 to circulate in the pulverization subsystem 401, and the other part The spent steam is condensed into condensed water by the spent steam water recovery subsystem 404 and then recovered and reused.

The steam powder generating and drying device includes: a raw coal bunker 5, a coal feeder 6, a coal mill 7, and a coarse powder separator 8. The steam powder separation device includes: a pulverizing pipeline 9 , a pulverized coal collector 10 , and a pulverized coal bin 11 . The desiccant generation device includes: exhaust steam pipeline 30, exhaust steam blower 31, exhaust steam circulation pipeline 32, exhaust steam heater 33, steam extraction pipeline 63, drain pipeline 64, superheated steam pipeline 34, booster fan 35, gas delivery pipe 52 , Control valve 51. The heat source in the exhaust steam heater 33 comes from the condensation heat release of the extracted steam in the steam turbine unit 502, and the exhaust steam is heated by the exhaust steam of the steam turbine unit 502 to obtain superheated steam as a desiccant. Among them, the steam extraction can directly extract the first-stage extraction steam in the steam turbine 60 whose temperature is sufficient to heat the exhaust steam to the temperature of the desiccant required by the pulverizing subsystem. In addition, the steam extraction can also extract multi-stage extraction steam with different temperature and pressure levels The exhaust steam is gradually heated up to the desiccant temperature required by the powder making subsystem.

Boiler host subsystem 402 is used to heat feed water to obtain high temperature and high pressure steam, including: boiler host 24 and pulverized coal burner 23 . The boiler host 24 includes a furnace (not shown in the figure) and a flue (not shown in the figure) connected to the smoke outlet of the furnace. The furnace is used to fully burn pulverized coal and air to release heat and generate flue gas. The water-cooled wall around the furnace absorbs the heat of the flue gas so that the temperature of the flue gas at the furnace outlet is within an appropriate range. Soda water heating surface, air preheater.

Air supply and powder delivery subsystem 403 includes: powder feeder 12, blower fan 14, warm air duct 55, air preheater 15, secondary air hot air duct 16, primary air hot air duct 17, warm air bypass duct 18, primary air Mixing chamber 19, primary air booster fan 20, primary air pipeline 21, powder feeding pipeline 22, air powder mixer 13. The condenser 37 preheats the cold air 2 to form warm air, and then the air preheater 15 further heats the warm air to obtain hot air.

The spent steam water recovery subsystem 404 includes: a spent steam water recovery device and a residual gas conveying device. The exhaust steam water recovery device includes: exhaust steam output pipe 36 , condenser 37 , cold water inlet pipe 65 , cold water outlet pipe 66 , exhaust steam bypass pipe 41 , and water collector 40 . The residual gas conveying device includes: an air extractor 38 , a residual gas pipeline 39 and a residual gas bypass pipeline 42 .

The flue gas purification subsystem 405 includes: a dust collector 25 , a smoke exhaust pipe 26 , an induced draft fan 27 , a desulfurization device 28 and a chimney 29 .

The overall connection relationship of superheated steam drying pulverizing coal-fired power generation system 501:

The raw coal bunker 5, the coal feeder 6, the coal mill 7, the pulverizing pipeline 9 and the pulverized coal collector 10 are sequentially connected, and the coarse powder separator 8 is arranged on the top of the coal pulverizer 7 and is connected with the coal pulverizer 7, The steam outlet of the pulverized coal collector 10 is connected with one end of the exhaust steam pipeline 30, the coal outlet of the pulverized coal collector 10 is connected with the inlet of the pulverized coal bin 11, and the outlet of the pulverized coal bin 11 is connected with the powder feeder 12, and the The powder machine 12 is connected with the powder inlet of the wind powder mixer 13 , the outlet of the wind powder mixer 13 is connected with one end of the powder feeding pipeline 22 , and the other end of the powder feeding pipeline 22 is connected with the pulverized coal burner 23 . The flue in the furnace is connected with the outlet of the furnace, and the air preheater 15 is located at the tail of the flue in the furnace.

The condenser 37 has correspondingly two refrigerant inlets and two refrigerant outlets, one refrigerant inlet of the condenser 37 is connected to one end of the cold water inlet pipe 65, and the other end of the cold water inlet pipe 65 is connected to the steam turbine unit 502, A refrigerant outlet corresponding to the refrigerant inlet is connected to the steam turbine unit 502 through the cold water outlet pipe 66 . The low-temperature condensed water of the steam turbine unit 502 enters the condenser 37 through the cold water inlet pipe 65 to condense exhaust steam, and then flows back to the steam turbine unit 502 through the cold water outlet pipe 66 . The outlet of the air blower 14 is connected to another refrigerant inlet of the condenser 37, and the other refrigerant outlet corresponding to the refrigerant inlet is connected to one end of the warm air duct 55, and the other end of the warm air duct 55 is connected to the air preheater 15. The air side inlet of the air preheater is connected with one end of the warm air bypass pipe 18, and the air side outlet of the air preheater 15 is connected with the pulverized coal burner 23 and the primary air through the secondary air hot air pipe 16 and the primary air hot air pipe 17 respectively. The air inlets of the mixing chamber 19 are connected. The other end of the warm wind bypass pipe 18 is connected with the air inlet of the primary air mixing chamber 19, and the primary air mixing chamber 19 is connected with the primary air booster blower 20, and the primary wind booster blower 20 is connected with the air powder by the primary air conduit 21. Mixer 13 is connected.

The inlet of the exhaust steam pipeline 30 is connected with the gas outlet of the pulverized coal collector 10 . The exhaust steam blower 31 is arranged on the exhaust steam pipeline 30 and is used for extracting the exhaust steam in the pulverized coal collector 10 . The inlet end of the exhaust steam circulation pipeline 32 is connected with the outlet of the exhaust steam pipeline 30, the outlet end of the exhaust steam circulation pipeline 32 is communicated with the air inlet of the exhaust steam heater 33, and the outlet of the exhaust steam heater 33 is connected with the superheated steam One end of the pipeline 34 is connected, the other end of the superheated steam pipeline 34 is connected with the inlet of the booster fan 35 , and the outlet of the booster fan 35 is connected with the coal mill 7 . The gas delivery pipe 52 is in communication with the exhaust steam circulation pipeline 32 , and the control valve 51 is arranged on the gas delivery pipe 52 for controlling opening and closing of the gas delivery pipe 52 .

The inlet of the exhaust steam output pipeline 36 is connected to the exhaust steam pipeline 30, the outlet of the exhaust steam output pipeline 36 is connected to the inlet of the condenser 37, the exhaust steam bypass pipeline 41 is connected in parallel with the condenser 37, and the water collector 40 is connected to the condenser The condenser 37 is connected to store the condensed water recovered by the condenser 37. The residual gas outlet of the condenser 37 is connected to the inlet of the air extractor 38, and the outlet of the air extractor 38 is respectively connected to the outlet of the residual gas pipeline 39. One end and one end of the residual gas bypass pipeline 42 , the other end of the residual gas bypass pipeline 42 is connected to the desulfurization device 28 , and the other end of the residual gas pipeline 39 is connected to the primary air mixing chamber 19 . The remaining non-condensable gas (hereinafter referred to as the remaining gas) after the water vapor is recovered by the condenser 37, the remaining gas enters the primary air mixing chamber 19 through the residual gas pipeline 39 and enters the furnace as the primary air, so that the residual gas may contain The combustible gas is fully burned in the furnace, and the remaining gas can also enter the desulfurization device 28 through the residual gas bypass pipe 42 . The remaining gas is other non-condensable gases mixed in the water vapor, such as the air seeping into the spent steam water recovery device and the combustible gas volatilized by the raw coal 1 during the pulverization process.

The outlet of the flue in the furnace, the dust remover 25 , the induced draft fan 27 , the desulfurization device 28 and the chimney 29 are connected through the exhaust pipe 26 in sequence.

One end of the water supply pipe 61 of the steam turbine unit 502 is connected to the water supply outlet of the steam turbine unit 502, and the other end is connected to the boiler main engine subsystem 402. One end of the steam delivery pipe 62 is connected to the boiler main engine subsystem 402, and the other end is connected to the steam turbine unit 502 is connected to the steam inlet, the steam turbine unit 502 is connected to the inlet of the exhaust steam heater 33 through the steam extraction pipeline 63, and the steam turbine unit 502 is connected to the outlet of the exhaust steam heater 33 through the drain pipeline 64, and the steam extracted from the steam turbine 60 The extracted steam enters the exhaust steam heater 33 through the steam extraction pipeline 63 to heat the exhaust steam, and then the extracted steam forms a drain and flows back to the steam turbine unit 502 through the drain pipeline 64 .

Fig. 4 is a flow chart of a superheated steam drying pulverizing coal-fired power generation system in an embodiment of the present invention.

As shown in Figure 4, the working principle of superheated steam drying pulverization type coal-fired power generation system 501:

Coal process (S1-S4): The raw coal 1 is transported from the raw coal bin 5 through the coal feeder 6 and enters the coal mill 7, and the raw coal 1 is ground into coal powder in the coal mill 7, and at the same time, it is fed into the coal mill 7 After the desiccant is dried, it is output from the coal mill 7. When the mixture of exhaust steam and coal powder at the outlet of the coal mill 7 passes through the coarse powder separator 8, the coarse powder is separated and enters the coal mill 7 again. Grind again. The steam-powder mixture passing through the coarse powder separator 8 enters the pulverized coal collector 10 through the pulverizing pipeline 9, and the pulverized coal collector 10 separates exhaust steam and pulverized coal in the pulverized steam mixture, and the pulverized coal bin 11 stores the pulverized coal , the pulverized coal in the pulverized coal bin 11 is sent into the air powder mixer 13 by the powder feeding machine 12, and is mixed with the primary air from the primary air mixing chamber 19 in the air powder mixer 13, and then sent to the coal powder by the powder feeding pipeline 22. The powder burner 23 enters the furnace to burn together with the secondary air and heat the feed water.

Fig. 5 is a block diagram of the air supply and powder delivery subsystem in the embodiment of the utility model.

The flow process (S4) of air: as shown in Fig. 3, Fig. 4, Fig. 5, cold wind 2 is that the boiler supply air is sent into condenser 37 by blower fan 14 and is used for condensing exhaust steam in condenser 37 as cooling medium, simultaneously The cold air 2 is preheated by exhaust steam to form warm air, and part of the warm air enters the air preheater 15 through the warm air duct 55 and is further heated by the flue gas to form hot air. Most of the hot air at the air side outlet of the air preheater 15 is directly led to the pulverized coal burner 23 through the secondary air hot air pipeline 16 as secondary air. Another small part of the hot air is mixed with the warm air delivered by the warm air bypass pipe 18 to form primary air in the primary air mixing chamber 19. The warm air delivered by the warm air bypass pipe 18 can adjust the temperature of the primary air, and the primary air is passed through After the primary air booster fan is pressurized, it enters the air-powder mixer 13 through the primary air duct 21, and then sends the pulverized coal into the furnace for combustion.

Flue gas flow: pulverized coal and air are burned in the furnace of the boiler 19 to generate flue gas, and the flue gas in the furnace is discharged from the flue in the furnace, and the air preheater 15 and the exhaust steam heater 33 are heated at the tail of the flue in the furnace. After heating, the exhausted flue gas is purified by the dust collector 25 and enters the induced draft fan 27 through the exhaust pipe 26, and then enters the desulfurization device 28, and the desulfurized flue gas 3 is discharged to the atmosphere by the chimney 29.

Fig. 6 is a block diagram of the pulverizing subsystem in the embodiment of the utility model.

As shown in FIG. 6 , the steam process ( S6 - 1 , S6 - 2 ): the water steam in the pulverizing subsystem 401 is composed of the water evaporation of the raw coal 1 . Between the outlet of the coal mill 7 and the inlet of the exhaust steam heater 33 is called exhaust steam, and between the outlet of the exhaust steam heater 33 and the inlet of the coal mill 7 is called superheated steam. The exhaust steam and coal powder are separated in the coal dust collector 10, and the separated exhaust steam is extracted by the exhaust steam fan 31 and divided into two parts, and a part of the exhaust steam is sent to the exhaust steam heater 33 by the exhaust steam circulation pipeline 32 for heating Superheated steam is formed, and the superheated steam is sent into the coal mill 7 through the superheated steam pipeline 34 as a desiccant, and the raw coal 1 entering the coal mill 7 is dried, and the steam-powder mixture at the outlet of the coal mill 7 is separated by the coal dust collector 10 Composed of pulverized coal and exhaust steam, the exhaust steam at this time is composed of superheated steam as a desiccant and moisture evaporated from the raw coal 1, and a part of the exhaust steam discharged from the steam outlet of the coal dust collector 10 enters the exhaust steam heater 33 And as a desiccant, it circulates in the powder making subsystem 401, and another part of exhaust steam is sent to the condenser 37 through the exhaust steam output pipeline 36 for recovery. The exhaust steam is cooled by the low-temperature condensed water of the steam turbine 60 and the cold air 2 in the condenser 37 to obtain a large amount of condensed water, which is collected in the water collector 40 .

Water supply process (S5): Water passes through the water supply pipe 61 and is heated by the main boiler subsystem 402 to form high-temperature and high-pressure water vapor. The high-temperature and high-pressure water vapor is sent to the steam turbine unit 502 through the steam delivery pipe 62 to perform work, and the steam turbine unit 502 drives the generator 70 jobs. Part of the extracted steam is extracted from the exhaust steam recovery system in the steam turbine unit 502 , and the extracted steam heats the exhaust steam in the exhaust steam heater 33 to generate superheated steam as a desiccant. In addition, the low-temperature condensed water in the steam turbine unit 502 is used to cool the exhaust steam in the condenser 37 , and then flows back into the steam turbine unit 502 .

The residual gas discharged from the spent steam and water recovery device after recovering water vapor is transported to the primary air mixing chamber 19 or the desulfurization device 28 through the residual gas conveying device. When the residual gas contains combustible gas, close the valve on the residual gas bypass pipeline 42, so that the residual gas enters the furnace through the residual gas pipeline 39 for combustion; when the residual gas does not contain combustible gas, open the residual gas bypass The valve on the pipeline 42 is used to make the residual gas pass through the flue gas purification subsystem 405 and then be discharged.

In this embodiment, first, the steam gas delivery pipe 52 is controlled by the control valve 51 to deliver the gas 50 to the exhaust steam circulation pipeline 32, and the gas 50 is heated and used as a desiccant to dry the raw coal 1 and pulverized coal entering the coal mill 7 , and then, after a preset time, the control valve 51 controls the steam gas delivery pipe 52 to stop delivering gas 50 to the exhaust steam circulation pipeline 32, and simultaneously opens the valve on the exhaust steam circulation pipeline 32 to establish exhaust steam recirculation. After running for a period of time, the gas 50 input by the steam gas pipeline 52 is gradually discharged by the exhaust steam output pipeline 36, so that the desiccant tends to be pure water vapor without other impurities, so that pure water vapor can be used as a desiccant for coal. powder to dry.

Function and effect of embodiment

In the superheated steam drying pulverization type coal-fired power generation system of this embodiment, the pulverization subsystem uses superheated steam as the desiccant of the pulverization subsystem and the ventilation medium of the coal mill, and the superheated steam is discharged from the coal pulverizer due to moisture in the coal The circulating exhaust steam formed by evaporation is heated by the exhaust steam heater using steam extraction in the steam turbine unit as the heating medium. In addition to the circulating exhaust steam that circulates in the subsystem, another part of the output exhaust steam produced by the continuous evaporation of moisture in the coal in the pulverization subsystem is used by the exhaust steam water recovery subsystem with the low-temperature condensed water in the steam turbine unit and the cold air. As a cooling medium for condensation recovery, the heat in the exhaust steam is used to preheat the cold air and the heat in the exhaust steam is also used in the steam turbine unit.

Moreover, the superheated steam in this embodiment is obtained by heating the exhaust steam by steam extraction of the steam turbine, that is, the heat source in the exhaust steam heater comes from the condensation and heat release of the steam extraction steam of the steam turbine unit, so that the condensation heat release of the extraction steam can be effectively used for coal-fired The drying output of the pulverizing system also means that the steam condensation waste heat in the steam turbine unit can be effectively used by the boiler system, which greatly reduces the loss of the cold source of the steam turbine thermal cycle.

Among the explosion suppression and inerting media flue gas, nitrogen and water vapor commonly used in industry, water vapor has the best explosion suppression performance. In this embodiment, superheated steam is used as the desiccant of the pulverization subsystem, so that the entire pulverization subsystem operates under a completely inert atmosphere, which ensures the safe and reliable operation of pulverization of high-volatile coal types such as lignite and Zhundong coal, and solves the problem of The combustion and explosion problems of the pulverizing system that have long plagued the safe and reliable operation of lignite and Zhundong coal units have been solved. In addition, the internal generation and recycling of the inert powder-making desiccant is realized. The powder-making process does not require additional steam and nitrogen production systems, nor does it need to consume flue gas, hot air and other media, making the powder-making process safe. Reliable, and the process is simple and efficient. Moreover, superheated steam is used as the desiccant in the pulverizing system, which improves the problem of poor particle size uniformity of pulverized coal particles caused by a large number of coal particles bursting in the process of furnace smoke drying and hot air drying, thereby helping to improve the combustion performance of pulverized coal. , Improve the efficiency of pulverized coal combustion.

In this embodiment, the water vapor generated inside the pulverizing subsystem is completely used as the desiccant and the pulverizing medium, which makes it extremely easy to recover the waste heat and water of the pulverizing exhaust steam that is almost pure water vapor. Through the waste heat recovery of waste steam from pulverization, the energy utilization efficiency of boilers and coal-fired energy systems can be further improved; moreover, the recovery and reuse of a large amount of water resources achieved by the waste steam recovery device while realizing waste heat recovery is even more beneficial to Coal-rich and water-scarce areas have immeasurable environmental significance.

The cold air delivered by the blower is used as a cooling medium in the exhaust steam recovery device to cool the exhaust steam, the cold air is preheated to form warm air, and the warm air finally enters the boiler for combustion, so that a large amount of latent heat of condensation of the exhaust steam can be effectively utilized by the boiler, thereby enabling The thermal efficiency of the boiler is greatly improved, making it possible for the thermal efficiency of the coal-fired power plant boiler to exceed 100% calculated based on the low calorific value of coal-fired. Due to the large amount of heat released by the condensation of exhaust steam, the optimum hot air temperature that can maximize the efficiency of the power generation system needs to be determined comprehensively with the increase in the temperature of the exhaust gas from the boiler. When the air cooling is not enough to fully recover the exhaust heat, the utility model further uses the low-temperature condensed water from the steam turbine unit as the cooling medium in the exhaust steam recovery device to cool the exhaust steam, and the low-temperature condensed water is heated to a certain temperature and then returns to the steam turbine unit. Reduce the amount of steam extracted by the low-pressure heater, so that the latent heat of condensation of the exhausted steam can be effectively used by the thermal system of the steam turbine unit, thereby further improving the power generation efficiency of the power plant. Through the combined application of two waste heat recovery methods of air cooling and water cooling, the recovery effect of exhausted steam and water can be fully guaranteed, and through the optimal distribution of heat from air cooling and water cooling, the power generation efficiency of the power generation system can be maximized, and the load of the power generation system can be changed. The adjustment during operation is more flexible and convenient. In addition, compared with the existing low-pressure economizer heated by flue gas, the volume and investment cost of the water-cooled condenser in the utility model will be greatly reduced.

In this embodiment, the steam-powder mixture is separated from the steam-powder mixture by the coal powder collector to obtain low-moisture coal powder, so that the quality of coal combustion can be greatly improved. The dried and upgraded pulverized coal is fed into the boiler by the air at a certain temperature for combustion, and there will be no problems such as low temperature in the furnace, unstable combustion, low _NOx combustion organization, and other problems. At the same time, the use of hot air to feed powder makes the content of inert gas in the primary air significantly reduced, thereby reducing the heat of the pulverized coal air flow and increasing the oxygen concentration in the primary air. The result of the combined effect is not only to improve the stable combustion performance and combustion efficiency of the pulverized coal flow, but also to make the low NOx combustion organization of the pulverized coal flow more convenient, so as to achieve clean, efficient and stable combustion. Moreover, the dried and upgraded coal powder is sent to the boiler for combustion by the primary air with a certain temperature in the air supply subsystem, and the moisture in the raw coal evaporated from the pulverization subsystem is no longer accompanied by the powder delivery medium. Entering the boiler, the amount of smoke exhausted by the boiler is greatly reduced, and the temperature of the corresponding boiler exhaust smoke is also reduced. Finally, the heat loss of the boiler exhaust smoke is greatly reduced, and the thermal efficiency of the boiler is significantly improved.

In this embodiment, because the residual gas conveying device sends combustible gas that may be contained in the steam back to the boiler for combustion, the combustion efficiency of the raw coal in the boiler system is fully guaranteed.

In summary, the embodiment can provide a green and high-efficiency coal-fired boiler unit, which solves the problem of unstable combustion of high-moisture coal-fired boilers, overcomes the shortcomings of low thermal efficiency of traditional high-moisture coal-fired boilers, and greatly improves the thermal efficiency of the boiler. The pulverization subsystem operates under an inert atmosphere, which improves the operational safety of the high-volatile coal pulverization subsystem. What is more prominent is that the use of superheated steam as a desiccant makes the waste heat and water recovery of the moisture in the coal very easy. At the same time, the efficiency of the coal-fired power generation system can be further improved through the recovery and utilization of the latent heat of steam condensation. Therefore, the superheated steam drying pulverization type coal-fired power generation system of the utility model has very significant energy-saving benefits and environmental protection significance.

Of course, the superheated steam drying pulverization type coal-fired power generation system involved in the utility model is not limited to the structures in the above-mentioned embodiments. The above content is only a basic explanation under the conception of the utility model, and any equivalent transformation made according to the technical solution of the utility model shall belong to the protection scope of the utility model.

The above embodiments are preferred cases of the present utility model, and are not intended to limit the protection scope of the present utility model.

The gas transported by the gas pipeline can be air, or any one of inert gases such as water vapor, nitrogen, and flue gas can be directly transported.

When the raw coal moisture is high, a raw coal pre-drying pipe can also be installed between the coal mill and the coal feeder. The inlet of the raw coal pre-drying pipe is connected to the superheated steam pipe through the steam conveying pipe, and the steam conveying pipe transports part of the superheated steam The raw coal is directly contacted with the raw coal in the raw coal pre-drying pipe, so that the raw coal is pre-dried, and the raw coal is dried safely through superheated steam.

The pre-drying agent in the raw coal pre-drying pipe can not only be part of the superheated steam transported through the steam delivery pipe, but also the superheated steam pipe can be directly connected to the inlet end of the raw coal pre-drying pipe. After drying, it enters the coal mill to further dry the steam-powder mixture.

Claims (9)

1. a superheat steam drying powder process type coal generating system, for burning to drive electrical power generators to raw coal, is characterized in that, comprising:

Boiler controller system, produces heat energy for carrying out burning to described raw coal, and utilizes described heat energy that feedwater heating is obtained high-temperature high-pressure steam, comprise: powder process subsystem, boiler host subsystem, air-supply powder feeding subsystem and exhaust steam Water Sproading subsystem; And

Steam Turbine, utilizing described high-temperature high-pressure steam do work thus drive described electrical power generators, comprising for carrying the feed pipe of described feedwater, for carrying steam pipeline and the steam turbine of described high-temperature high-pressure steam,

Wherein, described powder process subsystem comprises: for grinding described raw coal and carrying out drying by drier to described raw coal thus the vapour powder forming vapour powder mixture generates drying device, is separated the vapour powder separator obtaining coal dust and exhaust steam and the drier generating apparatus generating described drier to described vapour powder mixture

Described boiler host subsystem is used for described feedwater to be heated as described high-temperature high-pressure steam, comprises: burner hearth, the stove inner flue be connected with described furnace outlet, be positioned at the coal burner of described burner hearth entry position,

Described air-supply powder feeding subsystem comprises: be connected with described vapour powder separator for the machine supplying powder of pulverized coal conveying, the air and powder mixer be connected with described machine supplying powder, the First air mixing chamber be connected with described air and powder mixer, be positioned at described stove inner flue afterbody air preheater and for providing the pressure fan of cold wind

Described exhaust steam Water Sproading subsystem comprises: being connected with described Steam Turbine and being connected with described pressure fan utilizes the low-temperature condensate of described Steam Turbine and described cold wind to carry out the exhaust steam apparatus for recovering of condensation recovery to a part for described exhaust steam,

Described vapour powder separator comprises: be separated to described vapour powder mixture the coal collector obtaining described coal dust and described exhaust steam,

Described drier generating apparatus comprises: be connected with described coal collector for carry described exhaust steam exhaust steam pipeline, to be communicated with on described exhaust steam pipeline for carrying the exhaust steam circulating line of another part of described exhaust steam, to be connected with described exhaust steam circulating line and the described exhaust steam in described exhaust steam circulating line to be heated thus is formed as the exhaust steam heater of the superheated steam of described drier and described drier be delivered to described vapour powder and generate the superheat steam pipeline circulated in drying device

Described exhaust steam heater utilizes the condensation heat drawn gas of described steam turbine to add superheated steam described in thermosetting to the exhaust steam in described exhaust steam heater,

Described machine supplying powder for carrying described coal dust to described air and powder mixer,

Described air and powder mixer is mixed to get wind powder mixture to from the First air of described air-supply powder feeding subsystem and described coal dust,

Exhaust steam in described exhaust steam apparatus for recovering is become condensate water by the described cold wind condensation that the described low-temperature condensate of described Steam Turbine and described pressure fan provide, and described cold wind is obtained warm air by the heat preheating of described exhaust steam in described exhaust steam apparatus for recovering,

Described air preheater carries out heating to a part for described warm air and obtains hot blast, a part for described hot blast enters in described air and powder mixer as described First air with another part of described warm air after described First air mixing chamber mixes, another part of described hot blast directly enters in described coal burner as Secondary Air

Described coal burner burns to the described coal dust in described wind powder mixture,

Described coal dust and described First air, described Secondary Air burn and generate flue gas in described burner hearth.

2. superheat steam drying powder process type coal generating system according to claim 1, is characterized in that, also comprise:

Gas cleaning subsystem, exports with the afterbody of described stove inner flue and is connected, comprise: the deduster connected successively, air-introduced machine, desulfurizer, chimney.

3. superheat steam drying powder process type coal generating system according to claim 2, is characterized in that:

Wherein, described exhaust steam apparatus for recovering comprises: be communicated with the exhaust steam output channel on described exhaust steam pipeline, be connected with described exhaust steam output channel utilize described low-temperature condensate and described cold wind described exhaust steam is condensed into condensate water condenser, store the water collector that reclaims described condensate water and be connected with described exhaust steam output channel and described exhaust steam is directly introduced the exhaust steam bypass duct of described desulfurizer

Described condenser comprises the cold water inlet be connected with described Steam Turbine and the cold water outlet pipe be connected with described Steam Turbine,

Described low-temperature condensate flows in described condenser through described cold water inlet and carries out condensation to described exhaust steam, and described low-temperature condensate is back in described Steam Turbine through described cold water outlet pipe by after described exhaust steam heating.

4. superheat steam drying powder process type coal generating system according to claim 3, is characterized in that:

Wherein, described exhaust steam Water Sproading subsystem also comprises: for exporting the residual air conveying device of the residual gas that described condenser exports,

Described residual air conveying device comprises: be connected with the outlet of described condenser for the residual air pipeline that described residual gas delivered in described First air mixing chamber and be connected with described residual air pipeline and described residual gas is directly introduced described desulfurizer residual air bypass duct.

5. superheat steam drying powder process type coal generating system according to claim 1, is characterized in that:

Wherein, described vapour powder generation drying device also comprises: grind described raw coal and form the coal pulverizer of described vapour powder mixture with dry and be connected with the outlet of described coal pulverizer for being separated the meal in described vapour powder mixture and sending described meal back to mill separator in described coal pulverizer.

6. superheat steam drying powder process type coal generating system according to claim 5, is characterized in that:

Wherein, described vapour powder generates drying device and also comprises: outlet is connected for carrying out the predrying pipe of pre-dried raw coal and steam pipeline to described raw coal with the entrance of described coal pulverizer,

The import of the predrying pipe of described raw coal is communicated on described superheat steam pipeline by described steam pipeline,

Described superheated steam carries out predrying as predry drying prescription to the described raw coal in the predrying pipe of described raw coal.

7. superheat steam drying powder process type coal generating system according to claim 1, is characterized in that:

Wherein, described exhaust steam heater comprises: be connected with described Steam Turbine for draw gas described in carrying extraction line, for the hydrophobic drain water piping returning described Steam Turbine formed after described exhaust steam heater condensation heat that draws gas described in carrying.

8. superheat steam drying powder process type coal generating system as claimed in any of claims 1 to 7, is characterized in that:

Wherein, described powder process subsystem also comprises: be connected for carrying the appendix of gas and being located at for controlling to open and close the control valve of described appendix on described appendix with described exhaust steam circulating line,

Control described appendix by described control valve and carry described gas to described exhaust steam circulating line, as described drier after described gas is heated, after Preset Time, described control valve controls the stopping of described appendix and carries described gas to described exhaust steam circulating line.

9. superheat steam drying powder process type coal generating system according to claim 8, is characterized in that:

Wherein, described gas be in air or industrial inerting gas any one.