CN107841346A - Coal air part heat of gasification electricity fuel-gas multiple production device and method - Google Patents

Abstract

The invention relates to the field of coal partial gasification polygeneration, and aims to provide a thermal power gas polygeneration device and method of coal air partial gasification. Including circulating fluidized bed combustion furnace and circulating fluidized bed gasifier; the flue gas at the top of the former is connected to the flue gas discharge pipeline through the separator, and the separated material is connected to the circulating material inlet through the return device; the flue gas discharge pipeline passes through the steam generation The exhaust is realized after the flue gas heat exchanger in the device, and the steam generating device is connected to the heat supply user end and/or steam generating set through pipelines; the middle and lower part of the latter is provided with a semi-coke overflow port, the middle part is provided with a coal feeding port, and the top The gas is separated and then connected to the gas discharge pipeline; the separated material and semi-coke overflow port are connected to the circulating material inlet of the combustion furnace through the feeder. The invention combines the fluidized bed gasification technology with the semi-coke combustion technology, avoids the production of high-carbon-content semi-coke and bottom slag, improves the carbon conversion rate of the system, improves the overall efficiency of the coal utilization system, and reduces the complexity of equipment performance and operating costs.

Description

Coal air partial gasification thermal power gas cogeneration device and method

technical field

The invention relates to the field of coal partial gasification polygeneration, in particular to a coal air partial gasification thermoelectric gas polygeneration device and method.

Background technique

my country's energy structure is coal-rich, oil-poor and gas-deficient. Coal resources will be my country's main energy source at present and for a long time in the future, and coal resources account for 70% of my country's total energy consumption; however, the current main utilization method of coal is direct combustion power generation, which is inefficient and pollutes seriously , have had a serious impact on my country's sustainable economic development and people's lives. The existing circulating fluidized bed gasification technology has low carbon conversion rate and low utilization efficiency, which leads to serious waste of resources. At the same time, gasification requires a large amount of pure oxygen and needs to be equipped with a large-scale air separation unit, which increases system complexity and operating costs. Increase.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the existing technical deficiencies and provide a coal-air partial gasification thermoelectric gas polygeneration device and method.

For solving technical problem, solution of the present invention is:

Provided is a coal-air partial gasification thermoelectric gas cogeneration device, including a circulating fluidized bed combustion furnace with a slag discharge port; and a circulating fluidized bed gasification furnace with a slag discharge port;

The bottom of the circulating fluidized bed combustion furnace is provided with an air inlet, the middle and lower part is provided with a first circulating material inlet, and the top is provided with a flue gas outlet; wherein, the flue gas outlet at the top is connected to the flue gas discharge pipeline after passing through the second cyclone separator, The bottom of the second cyclone separator is connected to the second circulating material inlet in the middle of the circulating fluidized bed combustion furnace through the second feeder; the flue gas discharge pipeline is discharged after passing through the flue gas heat exchanger in the steam generating device, and the steam is generated The device is connected to the heat supply user end and/or steam generator set through pipelines;

The bottom of the circulating fluidized bed gasifier is provided with an air inlet, the middle and lower part is provided with a semi-coke overflow port, the middle part is provided with a coal feeding port, and the top is provided with a gas outlet; wherein, the gas outlet at the top is connected to the first cyclone separator To the gas discharge pipeline; the bottom of the first cyclone separator is connected to the first circulating material inlet of the circulating fluidized bed combustion furnace through the first return feeder, and the semi-coke overflow port is connected to the first circulating material through the third return feeder Entrance.

In the present invention, the inside of the circulating fluidized bed gasifier is divided into an air chamber, a dense phase area and a dilute phase area from bottom to top; wherein, the air inlet of the gasifier is connected with the air chamber, and the coal feed port is located in the dense phase area. In the middle of the zone, the semi-coke overflow port is located at the lower part of the dense phase zone, and the gas outlet is located at the top of the dilute phase zone;

The interior of the fluidized bed combustion furnace is divided into an air chamber, a dense phase area and a dilute phase area from bottom to top; wherein, the air inlet of the combustion furnace is connected with the air chamber, the first circulation material inlet is located at the lower part of the dense phase area, and the second circulation The material inlet is in the middle of the dense phase area, and the flue gas outlet is located at the top of the dilute phase area.

In the present invention, the gas discharge pipeline is connected to the gas user end.

In the present invention, the bottom of the circulating fluidized bed combustion furnace is provided with a combustion furnace lock hopper with a slagging outlet, and the bottom of the circulating fluidized bed gasifier is provided with a gasifier lock hopper with a slagging outlet.

The present invention further provides a coal partial gasification graded conversion method based on the aforementioned device, comprising the following steps:

(1) Add granular coal to the middle of the dense phase zone of the circulating fluidized bed gasifier through the coal feeding port, and control the mass ratio of coal to air to be 1.65 to 1.8; the circulating fluidized bed gasifier is under normal pressure Operation, the operating temperature is 900-1000°C; the granular coal is mixed with the air from the bottom in the dense phase area, so that the coal is partially gasified and gas is generated, and the air is used as the gasification agent in this process;

(2) After the gas discharged from the circulating fluidized bed gasifier is dedusted by the first-stage cyclone separator, it is sent to the gas user end through the gas discharge pipeline; the separated dust is sent to the circulating fluidized bed combustion furnace by the feeder; After the gasification reaction in the fluidized bed gasifier, semi-coke materials are generated, which are discharged from the semi-coke overflow port and sent to the circulating fluidized bed combustion furnace by the return device;

(3) The circulating fluidized bed combustion furnace operates at normal pressure, and the operating temperature is 900-950°C; the mass ratio of the bottom air to the semi-coke material is controlled to be 1-1.2, so that the semi-coke material is in the dense phase area and the air from the bottom A combustion reaction occurs to generate flue gas at a temperature of 900-950°C;

(4) The flue gas in the circulating fluidized bed combustion furnace is dedusted by the cyclone separator and sent to the flue gas discharge pipeline, and then discharged after passing through the flue gas heat exchanger in the steam generating device; the steam generated by the steam generating device passes through The pipeline is sent to the heating user end and/or steam generator set to realize steam heating and/or and/or steam power generation;

The dust separated by the cyclone separator is sent back to the circulating fluidized bed combustion furnace by the feeder, and participates in the combustion reaction again; the semi-coke material described in step (3) includes the semi-coke material discharged from the circulating fluidized bed gasifier and Two cyclones separate the resulting dust.

In the present invention, the particle size of the granular coal is 1-10 mm.

Description of invention principle:

Combining the characteristics of the chemical structure of coal, the present invention first converts the part with good activity and easy gasification into gas for industrial production, and then burns the produced semi-coke which is not easy to gasify as raw material to produce high-temperature flue gas for use High-temperature steam is produced in subsequent processes for power generation or heat supply.

Coal partial gasification polygeneration technology organically combines circulating fluidized bed air gasification with semi-coke combustion, which improves the carbon conversion rate and can produce heat, electricity, gas and other products at the same time. The requirements for components and calorific value are low, and a calorific value of about 1000 kcal can meet its requirements, while the gasification efficiency is not overemphasized in the coal air partial gasification process, and the calorific value of the generated gas can meet the needs of industrial production; at the same time, semi-coke The heat generated by combustion can be used for heating or power supply, which improves the utilization efficiency of coal and realizes the optimization of the overall benefit of the coal utilization system. Compared with the current fluidized bed gasification technology, this technology has the advantages of high carbon conversion rate, low oxygen consumption, and low equipment cost.

Compared with the prior art, the present invention has the beneficial effects:

1. Compared with the existing single fluidized bed gasification, the present invention combines the fluidized bed gasification technology with the semi-coke combustion technology, avoids the production of high carbon content semi-coke and bottom slag, and improves the carbon conversion of the system Rate.

2. The present invention adopts the gasification reaction of coal and air, does not pursue excessively high gasification carbon conversion rate, and can be applied to industrial production that does not require high gas composition and calorific value; Combustion is carried out in the middle to form high-temperature flue gas, which can be used to produce high-temperature and high-pressure steam for power generation or heat supply. The organic combination of the two technologies improves the overall efficiency of the coal utilization system.

3. The present invention adopts air blowing, avoids the use of an air separation unit, reduces the complexity of equipment and operating costs, and has greater advantages in economy.

Description of drawings

Fig. 1 is a schematic diagram of an implementation of the device of the present invention.

In the figure: coal feeding port 1, air inlet 2, circulating fluidized bed gasification furnace 3, first feeder 4, first cyclone separator 5, gas discharge pipeline 6, second cyclone separator 7, second Second feeder 8, circulating fluidized bed combustion furnace 9, air inlet 10, flue gas discharge pipeline 11, semi-coke overflow port 12, third feeder 13, first circulating material inlet 14, second circulating material inlet 15. Gasifier lock hopper 16, combustion furnace lock hopper 17, flue gas heat exchanger 18, gas user terminal 19, heating user terminal 20, steam generator set 21.

Detailed ways

The implementation of the present invention will be described below in conjunction with the accompanying drawings.

Coal air partial gasification heat, electricity and gas polygeneration device in the present invention comprises circulating fluidized bed combustion furnace 9 and circulating fluidized bed gasification furnace 3, the bottom of the former is provided with the combustion furnace lock bucket 17 with slagging outlet, and the latter A gasifier lock hopper 16 with a slagging port is provided at the bottom.

The bottom of the circulating fluidized bed combustion furnace 9 is provided with an air inlet 10, the middle and lower part is provided with a first circulating material inlet 14, and the top is provided with a flue gas outlet; wherein, the flue gas outlet at the top is connected to the flue gas discharge after passing through the second cyclone separator 7 Pipeline 11, the bottom of the second cyclone separator 7 is connected to the second circulating material inlet 15 in the middle of the circulating fluidized bed combustion furnace 9 through the second feeder 8; the flue gas discharge pipe 11 line passes through the flue gas in the steam generating device Discharge is realized behind the heat exchanger 18; the steam generating device is connected to the heat supply user end 20 through a pipeline, or connected to a steam generator set 21 through a pipeline (such as sufficient steam generation, heat supply and power generation can also be performed simultaneously).

An air inlet 2 is provided at the bottom of the circulating fluidized bed gasifier 3, a semi-coke overflow port 12 is provided at the middle and lower part, a coal feeding port 1 is provided at the middle, and a gas outlet is provided at the top; wherein, the gas outlet at the top passes through the first cyclone separator 5 is then connected to the gas discharge pipeline 6, and the gas discharge pipeline 6 is connected to the gas user end 19. The bottom of the first cyclone separator 5 is connected to the first circulating material inlet 14 of the circulating fluidized bed combustion furnace 9 through the first feeder 4, and the semi-coke overflow port 12 is connected to the first circulation through the third feeder 13. Material inlet 14.

The interior of the circulating fluidized bed gasifier 3 is divided into an air chamber, a dense-phase area and a dilute-phase area from bottom to top; its air inlet 2 is connected to the air chamber, and the coal feeding port 1 is located in the middle of the dense-phase area, and the semi-coke overflows The mouth 12 is located at the lower part of the dense-phase area, and the gas outlet is located at the top of the dilute-phase area; the inside of the circulating fluidized bed combustion furnace 9 is divided into an air chamber, a dense-phase area and a dilute-phase area from bottom to top; its air inlet 10 is connected with the air chamber, The first circulating material inlet 14 is located at the lower part of the dense phase area, the second circulating material inlet 15 is located at the middle of the dense phase area, and the flue gas outlet is located at the top of the dilute phase area.

The coal partial gasification graded conversion method based on the device of the present invention comprises the following steps:

(1) Add granular coal with a particle size of 1 to 10mm to the middle of the dense phase zone of the circulating fluidized bed gasifier 3 through the coal feed port 1, and control the mass ratio of coal to air to be 1.65 to 1.8; the circulating fluidized The bed gasifier 3 operates under normal pressure, and the operating temperature is 900-1000°C; the granular coal is mixed with the air from the bottom in the dense phase area, so that the coal is partially gasified and gas is generated, and the air is used as the gasification agent in this process ;

(2) After the gas discharged from the circulating fluidized bed gasifier 3 is dedusted by the first cyclone separator 5 (a second-stage cyclone separator can also be added), it is sent to the gas user terminal 19 through the gas discharge pipeline 6; The dust is sent to the circulating fluidized bed combustion furnace 9 by the first feeder 4; the semi-coke material is generated after the gasification reaction in the circulating fluidized bed gasification furnace 3, and is discharged from the semi-coke overflow port 12 by the third return Feeder 13 is sent to circulating fluidized bed combustion furnace 9;

(3) The circulating fluidized bed combustion furnace 9 operates under normal pressure, and the operating temperature is 900-950°C; the mass ratio of the air at the bottom and the semi-coke material is controlled to be 1-1.2, so that the semi-coke material is in the dense phase area and the gas from the bottom The air undergoes a combustion reaction to generate flue gas at a temperature of 900-950°C; the semi-coke material here includes the semi-coke material discharged from the circulating fluidized bed gasifier and the dust separated by two cyclone separators.

(4) The flue gas in the circulating fluidized bed combustion furnace 9 is sent to the flue gas discharge pipeline 11 after being dedusted by the second cyclone separator 7, and is discharged after passing through the flue gas heat exchanger 18 in the steam generating device; The steam generated by the generating device is sent to the heat supply user end 20 and/or the steam generator set 21 through pipelines to realize steam heat supply and/or steam power generation. The dust separated by the second cyclone separator 7 is sent back to the circulating fluidized bed combustion furnace 9 by the second feeder 8, and participates in the combustion reaction again;

Specific application examples:

The coal is fed to the dense phase area of the circulating fluidized bed gasifier 3 through the coal feeding port 1, the coal feeding rate is 180t/h, mixed with the air from the bottom, and the air-to-coal ratio is 1.75. In order to control the amount of tar produced by gasification, the temperature of the circulating fluidized bed gasifier 3 is controlled at about 970°C. In the circulating fluidized bed gasifier 3, coal and air undergo a gasification reaction to generate gas. The gas flow rate is 456960m ³ /h, and it leaves the circulating fluidized bed gasifier 3 through the two-stage cyclone separator. The gas is mainly used for industrial use, and the semi-coke and fly ash separated by the cyclone separator are transported to the circulating fluidized bed combustion furnace 9 through the first return feeder 4 for combustion.

The main feed of the circulating fluidized bed combustion furnace 9 is the semi-coke material from the circulating fluidized bed gasification furnace 3 . In the circulating fluidized bed gasification furnace 3, the semi-coke material produced by partial coal gasification overflows from the overflow port 12 at the top of the dense phase area, and is directly transported to the fluidized bed combustion furnace 9 through the third feeder 13. The feed rate of coke material is 17804.9kg/h. In the circulating fluidized bed combustion furnace 9, the semi-coke material is burned with air to produce high-temperature flue gas, and the air flow rate is 320400kg/h. The high-temperature flue gas generated by combustion carries high-temperature material into the second cyclone separator 7, and the separated The high-temperature material is sent back to the circulating fluidized bed combustion furnace 9 through the second feeder 8 . The circulating fluidized bed combustion furnace 9 operates under normal pressure, and the operating temperature is controlled to be 900-950°C.

Claims (6)

1. a kind of coal air part heat of gasification electricity fuel-gas multiple produces device, including the CFBC provided with slag-drip opening Stove；Characterized in that, also include the circle fluidized-bed gasification furnace provided with slag-drip opening；

The bottom of the CFBC stove sets air intake, and middle and lower part sets first circulation material inlet, and top sets flue gas Outlet；Wherein, the exhanst gas outlet at top is followed by fume emission pipeline, the bottom of the second cyclone separator through the second cyclone separator The material returning device of portion second is connected to the second circulation material inlet in the middle part of CFBC stove；Fume emission pipeline passes through steam Discharge is realized after flue gas heat-exchange unit in generating means, steam raising plant is connected to heat supply user end and/or steam by pipeline Generating set；

The bottom of the circle fluidized-bed gasification furnace sets air intake, and middle and lower part sets semicoke overfall, and middle part sets coal feedstock mouth, Top sets gas outlet；Wherein, the gas outlet at top is followed by gas emission pipeline through the first cyclone separator；First whirlwind The material returning device of bottom first of separator is connected to the first circulation material inlet of CFBC stove, and semicoke overfall is through Three material returning devices are connected to first circulation material inlet.

2. device according to claim 1, it is characterised in that

The inside of the circle fluidized-bed gasification furnace is divided into air compartment, emulsion zone and dilute-phase zone from the bottom to top；Its air intake and wind Room is connected, and coal feedstock mouth is located in the middle part of emulsion zone, and semicoke overfall is located at emulsion zone bottom, and gas outlet is located at dilute-phase zone top Portion；

The inside of the CFBC stove is divided into air compartment, emulsion zone and dilute-phase zone from the bottom to top；Its air intake and wind Room is connected, and first circulation material inlet is located at emulsion zone bottom, second circulation material inlet emulsion zone middle part, and exhanst gas outlet is located at At the top of dilute-phase zone.

3. device according to claim 1, it is characterised in that the gas emission pipeline is connected to gas user end.

4. device according to claim 1, it is characterised in that the bottom of CFBC stove sets the combustion with slag-drip opening Stove lock hopper is burnt, the bottom of circle fluidized-bed gasification furnace sets the gasification furnace lock hopper with slag-drip opening.

5. the coal partial gasification staged conversion method based on claim 1 described device, it is characterised in that including following steps Suddenly：

(1) graininess coal is added in the middle part of the emulsion zone of circle fluidized-bed gasification furnace by coal feedstock mouth, controls coal Mass ratio with air is 1.65~1.8；Circle fluidized-bed gasification furnace is run at ambient pressure, 900~1000 DEG C of running temperature； Graininess coal mixes in emulsion zone with the air from bottom, makes coal that partial gasification occur and generates combustion gas, during being somebody's turn to do Air is as gasifying agent；

(2) combustion gas of circle fluidized-bed gasification furnace discharge delivers to combustion gas after cyclone separator dedusting by gas emission pipeline User terminal；Separating obtained dust delivers to CFBC stove by material returning device；Through gasification reaction in circle fluidized-bed gasification furnace Semicoke material is generated afterwards, and CFBC stove is delivered to by material returning device after the discharge of semicoke overfall；

(3) CFBC stove runs for normal pressure, and running temperature is 900~950 DEG C；Control bottom air and semicoke material Mass ratio be 1~1.2, make semicoke material emulsion zone with from bottom air occur combustion reaction, generation temperature be 900~950 DEG C of flue gas；

(4) flue gas in CFBC stove delivers to fume emission pipeline after carrying out dedusting by cyclone separator, by steaming Discharge is realized after flue gas heat-exchange unit in vapour generating means；Steam delivers to heat supply user by pipeline caused by steam raising plant End and/or steam-electric power unit, realize steam heating and/or steam-electric power；

The separating obtained dust of cyclone separator returns to CFBC stove by material returning device, participates in combustion reaction again；Step Suddenly semicoke material described in (3) includes the semicoke material from circle fluidized-bed gasification furnace discharge and two cyclone separator separation institutes Obtain dust.

6. according to the method for claim 5, the granularity of the graininess coal is 1~10mm.