阅读说明：本技术 一种煤灰渣冷却排渣方法 (Cooling and deslagging method for coal ash ) 是由 刘海建 王光辉 孙富民 马洛洛 吴松怡 段海龙 谭旭 于 2019-02-25 设计创作，主要内容包括：本发明公开了一种煤灰渣冷却排渣方法,其包括以下步骤：(1)冷却气一次冷却,(2)蒸汽二次冷却,(3)冷却水三次冷却,(4)排渣罐的进渣及排渣。本发明的优点在于,向灰渣管内部通入二氧化碳代替蒸汽控制排渣速度,并对灰渣进行一次冷却,减少了蒸汽的使用量,降低了蒸汽制造设备及原料煤的投入成本,而且二氧化碳进入流化床气化炉后,可抑制流化床气化炉内碳与氧气反应生成二氧化碳,促进碳和水蒸气反应的进行；灰渣管内液面处的冷却水不断蒸发成蒸汽,蒸汽对灰渣进行二次冷却,而且蒸汽通过灰渣管进入流化床气化炉进行利用,降低了5％的外界蒸汽供应量,减少了蒸汽的投入成本。(The invention discloses a method for cooling and deslagging coal ash, which comprises the following steps: (1) primary cooling of cooling gas, (2) secondary cooling of steam, (3) tertiary cooling of cooling water, and (4) slag feeding and discharging of a slag discharging tank. The invention has the advantages that carbon dioxide is introduced into the ash residue pipe instead of steam to control the slag discharge speed, and the ash residue is cooled for one time, thereby reducing the use amount of the steam, lowering the investment cost of steam manufacturing equipment and raw material coal, and inhibiting carbon in the fluidized bed gasification furnace from reacting with oxygen to generate carbon dioxide after the carbon dioxide enters the fluidized bed gasification furnace, and promoting the reaction of the carbon and water vapor; the cooling water at the liquid level in the ash pipe is continuously evaporated into steam, the steam carries out secondary cooling on the ash, and the steam enters the fluidized bed gasification furnace through the ash pipe for utilization, so that the external steam supply amount is reduced by 5%, and the input cost of the steam is reduced.)

1. A cooling and deslagging method for coal ash is characterized by comprising the following steps: (1) cooling gas primary cooling, (2) steam secondary cooling, (3) cooling water tertiary cooling, and (4) slag feeding and discharging of a slag discharging tank; wherein the content of the first and second substances,

(1) primary cooling of cooling gas: the coal ash at 850-900 ℃ discharged from the fluidized bed gasification furnace enters a coal ash pipe, cooling gas carbon dioxide enters a pipe body of a gas distribution pipe through a gas filling pipe and is uniformly sprayed out through a sintered metal filter element, the coal ash in the coal ash pipe is cooled for one time, meanwhile, the carbon dioxide and residual carbon in high-temperature coal ash generate endothermic reduction reaction, the coal ash is further cooled, the coal ash cooled to 450-550 ℃ moves downwards along the coal ash pipe, and the carbon dioxide after heat exchange with the coal ash moves upwards along the coal ash pipe and enters the fluidized bed gasification furnace;

(2) secondary cooling by steam: the coal ash after primary cooling moves downwards along the ash pipe and is contacted with cooling water, the cooling water at the liquid level of the cooling water absorbs the heat of the coal ash and is evaporated, steam generated by evaporation moves upwards along the ash pipe to cool the coal ash for the second time, the temperature of the coal ash after secondary cooling is 200-300 ℃, and the steam after heat exchange with the coal ash moves upwards along the ash pipe and enters a fluidized bed gasification furnace to be used as a gasification agent;

(3) cooling water for three times: immersing coal ash slag in cooling water after entering the cooling water, and cooling the coal ash slag in the cooling water for three times until the temperature is below 150 ℃;

(4) slag feeding and discharging of the slag discharging tank: after the coal ash is cooled for three times, the coal ash moves downwards to enter a slag collecting tank for temporary storage, when the coal ash in the slag collecting tank is exhausted, a second slag discharging valve is closed, water injection is started through a water injection valve, when a slag discharging liquid level sensor detects that the liquid level of water injection reaches a preset value of a controller, and the detection value of a slag discharging tank pressure sensor is equal to the detection value of a cold slag tank pressure sensor, the controller sends a closing signal to the water injection valve, the water injection valve is closed, a first slag discharging valve is opened, high-pressure gas at the top of the slag discharging tank moves upwards to enter the slag collecting tank, and the coal ash at the lower part of the slag collecting tank is disturbed and moves downwards to enter the slag; after the feeding of the slag discharging tank is finished, the first slag discharging valve is closed, the pressure release valve is opened, after the detection value of the pressure sensor of the slag discharging tank is equal to zero, the second slag discharging valve and the slag flushing valve are opened, the coal ash is smoothly taken away by high-pressure injection water, and the flow direction of the coal ash along the slag discharging main pipe is towards the slag storage device.

2. The method for cooling and removing the ash slag according to claim 1, wherein the water injected by the slag discharging tank in the step (4) and the conveying water when the slag discharging main pipe performs slag discharging are provided by cooling water pipes.

3. The method for cooling and discharging the coal ash according to claim 1, wherein the water injected by the slag discharging tank and the water delivered by the slag discharging main pipe in the step (4) are both the water discharged by the slag collecting tank through a water balance valve.

4. The method for cooling and slagging coal ash according to claim 3, wherein the slag collecting tank flushing valve and the control valve are opened at regular time to flush the pipeline through which slag water flows by using cooling water discharged from the cooling water pipe.

5. The method for cooling and slagging coal ash according to any of claims 1 to 4, wherein in step (1), when the controller receives a value detected by the ash temperature sensor and is greater than 500 ℃, the controller sends an opening degree increase signal to the inflation control valve; in the step (3), when the controller receives that the detection value of the cold slag tank temperature sensor is more than 150 ℃, the controller sends an opening degree increasing signal to the water inlet control valve; in the step (4), when the detection value of the slag discharging tank pressure sensor is greater than that of the cold slag tank pressure sensor, the controller sends an opening signal to the pressure relief valve.

6. The cooling and deslagging method for coal ash residues according to any one of claims 1 to 4, characterized in that in step (3), when the low liquid level sensor detects that the liquid level of the cooling water in the cold slag tank reaches a preset liquid level lower limit value, the opening degree of the water inlet control valve is increased, the opening degree of the water balance valve is decreased, and water is replenished to the tank body; when the high liquid level sensor detects that the liquid level of the cooling water reaches the preset upper limit value of the liquid level, the opening degree of the water inlet control valve is reduced, and the opening degree of the water balance valve is increased, so that the liquid level of the cooling water in the tank body is always kept between the lowest liquid level and the highest liquid level.

7. The cooling and deslagging method for the coal ash according to claim 5, characterized in that in the step (3), when the low liquid level sensor detects that the liquid level of the cooling water in the cold slag tank reaches a preset liquid level lower limit value, the opening degree of the water inlet control valve is increased, the opening degree of the water balance valve is decreased, and water is supplemented to the tank body; when the high liquid level sensor detects that the liquid level of the cooling water reaches the preset upper limit value of the liquid level, the opening degree of the water inlet control valve is reduced, and the opening degree of the water balance valve is increased, so that the liquid level of the cooling water in the tank body is always kept between the lowest liquid level and the highest liquid level.

The technical field is as follows:

the invention relates to a slag discharging method, in particular to a cooling slag discharging method for coal ash.

Background art:

the coal powder and the gasifying agent are gasified in the fluidized bed gasifier to generate crude gas, and high-temperature ash is generated after the coal powder is gasified. In order to discharge ash in the fluidized bed gasification furnace, a chilling chamber and a slag discharge tank are generally communicated with a slag discharge port of the fluidized bed gasification furnace in sequence, and the slag discharge process comprises the following steps: ash in the fluidized bed gasifier enters a slag discharging channel through a slag discharging port, steam is introduced into the slag discharging channel to control the slag discharging speed, cooling water is introduced into the slag discharging channel to cool the ash in the descending process, the ash and the cooling water fall into a chilling chamber from the slag discharging channel, and the cooled ash in the chilling chamber is discharged through a slag discharging tank; in the process, the slag discharge speed is generally controlled by adding hot steam into the slag discharge channel, the ash slag is cooled by introducing cooling water into the slag discharge channel, 90% of heat in the ash slag is transferred to the cooling water in a sensible heat mode, the cooling water is forcibly circulated by a circulating pump, and the heat is removed by a heat exchanger.

The slag discharge device has the following problems in the use process: 1. ash slag needs to be cooled in the chilling chamber for a period of time, the chilling chamber continuously feeds the slag, when the liquid level of cooling water in the chilling chamber exceeds a water outlet, a circulating pump needs to be used for forced circulation, the cooling water contains part of the ash slag, the circulating pump and a heat exchanger are blocked in the circulating cooling process, the operation of a slag discharging device is interrupted, and the slag discharging efficiency is influenced; 2. ash in the slag discharging tank falls into the slag storage device through self weight, the slag storage device can only be placed below the slag discharging tank, the placement position of equipment is limited, the overall height of the slag discharging equipment is high, and the maintenance is inconvenient; 3. the steam is introduced into the deslagging channel to control the deslagging speed, so that the use amount of the steam is increased, the steam needs to be produced by a steam boiler, and the investment cost of equipment and raw material coal is increased; 4. the slag discharging channel is internally provided with cooling water to cool the slag, the slag can not be completely immersed in the cooling water, and the cooling effect is poor.

The invention content is as follows:

the invention aims to provide a coal ash cooling and deslagging method which can reduce the amount of steam supplied from the outside of a fluidized bed gasification furnace, inhibit the generation of carbon dioxide in gasification reaction by adding normal-temperature carbon dioxide gas into an ash tube and improve the gasification efficiency of raw coal.

The invention is implemented by the following technical scheme: a cooling and deslagging method for coal ash comprises the following steps: (1) cooling gas primary cooling, (2) steam secondary cooling, (3) cooling water tertiary cooling, and (4) slag feeding and discharging of a slag discharging tank; wherein the content of the first and second substances,

(1) primary cooling of cooling gas: the coal ash at 850-900 ℃ discharged from the fluidized bed gasification furnace enters a coal ash pipe, cooling gas carbon dioxide enters a pipe body of a gas distribution pipe through a gas filling pipe and is uniformly sprayed out through a sintered metal filter element, the coal ash in the coal ash pipe is cooled for one time, meanwhile, the carbon dioxide and residual carbon in high-temperature coal ash generate endothermic reduction reaction, the coal ash is further cooled, the coal ash cooled to 450-550 ℃ moves downwards along the coal ash pipe, and the carbon dioxide after heat exchange with the coal ash moves upwards along the coal ash pipe and enters the fluidized bed gasification furnace;

(2) secondary cooling by steam: the coal ash after primary cooling moves downwards along the ash pipe and is contacted with cooling water, the cooling water at the liquid level of the cooling water absorbs the heat of the coal ash and is evaporated, steam generated by evaporation moves upwards along the ash pipe to cool the coal ash for the second time, the temperature of the coal ash after secondary cooling is 200-300 ℃, and the steam after heat exchange with the coal ash moves upwards along the ash pipe and enters a fluidized bed gasification furnace to be used as a gasification agent;

(3) cooling water for three times: immersing coal ash slag in cooling water after entering the cooling water, and cooling the coal ash slag in the cooling water for three times until the temperature is below 150 ℃;

(4) slag feeding and discharging of the slag discharging tank: after the coal ash is cooled for three times, the coal ash moves downwards to enter a slag collecting tank for temporary storage, when the coal ash in the slag collecting tank is exhausted, a second slag discharging valve is closed, water injection is started through a water injection valve, when a slag discharging liquid level sensor detects that the liquid level of water injection reaches a preset value of a controller, and the detection value of a slag discharging tank pressure sensor is equal to the detection value of a cold slag tank pressure sensor, the controller sends a closing signal to the water injection valve, the water injection valve is closed, a first slag discharging valve is opened, high-pressure gas at the top of the slag discharging tank moves upwards to enter the slag collecting tank, and the coal ash at the lower part of the slag collecting tank is disturbed and moves downwards to enter the slag; after the feeding of the slag discharging tank is finished, the first slag discharging valve is closed, the pressure release valve is opened, after the detection value of the pressure sensor of the slag discharging tank is equal to zero, the second slag discharging valve and the slag flushing valve are opened, the coal ash is smoothly taken away by high-pressure injection water, and the flow direction of the coal ash along the slag discharging main pipe is towards the slag storage device.

Further, the water injected by the slag discharging tank in the step (4) and the conveying water during slag discharging of the slag discharging main pipe are provided by cooling water pipes.

Further, in the step (4), the water injected by the slag discharging tank and the conveying water of the slag discharging main pipe are water discharged by the slag collecting tank through a water balance valve.

Furthermore, a flushing valve of the slag collecting tank and a control valve are opened at regular time, and cooling water discharged by a cooling water pipe is used for flushing a pipeline through which slag water flows.

Further, in the step (1), when the detected value of the ash temperature sensor received by the controller is more than 500 ℃, the controller sends an opening degree increase signal to the inflation control valve; in the step (3), when the controller receives that the detection value of the cold slag tank temperature sensor is more than 150 ℃, the controller sends an opening degree increasing signal to the water inlet control valve; in the step (4), when the detection value of the slag discharging tank pressure sensor is greater than that of the cold slag tank pressure sensor, the controller sends an opening signal to the pressure relief valve.

Further, in the step (3), when the low liquid level sensor detects that the liquid level of the cooling water in the cold slag tank reaches a preset liquid level lower limit value, the opening degree of the water inlet control valve is increased, the opening degree of the water balance valve is decreased, and water is supplemented to the tank body; when the high liquid level sensor detects that the liquid level of the cooling water reaches the preset upper limit value of the liquid level, the opening degree of the water inlet control valve is reduced, and the opening degree of the water balance valve is increased, so that the liquid level of the cooling water in the tank body is always kept between the lowest liquid level and the highest liquid level.

The invention has the advantages that: 1. the cooling water at the liquid level in the ash pipe is continuously evaporated into steam, the steam carries out secondary cooling on the ash, and the steam enters the fluidized bed gasification furnace through the ash pipe for utilization, so that the external steam supply amount is reduced by 5%, and the input cost of the steam is reduced; the low-temperature cooling water is supplemented after the cooling water is evaporated, and forced circulation cooling of the cooling water is not needed, so that the blockage of a circulating pump and a heat exchanger in the circulation cooling process is avoided, the smooth operation of a slag discharging device is ensured, and the slag discharging efficiency is ensured; 2. ash in the slag discharging main pipe is conveyed by high-pressure water and can be conveyed into the slag storage device at the tail end of the slag discharging main pipe along the slag discharging main pipe, so that the placement position of the slag storage device is not limited, the overall height of slag discharging equipment is reduced, and the maintenance is convenient; 3. carbon dioxide is introduced into the ash residue pipe to replace steam to control the deslagging speed, the ash residue is cooled for the first time, the using amount of the steam is reduced, the input cost of steam manufacturing equipment and raw material coal is reduced, and the carbon dioxide enters the fluidized bed gasification furnace, so that the concentration of the carbon dioxide in the fluidized bed gasification furnace is increased, the carbon in the fluidized bed gasification furnace can be inhibited from reacting with oxygen to generate the carbon dioxide, the reaction of the carbon and water vapor is promoted, and the effective gas component content of the crude gas is improved; 4. after entering the tank body, the ash falls into and is immersed in cooling water, and the cooling water can fully cool the ash, so that the cooling effect is ensured; 5. a plurality of balance holes are formed in the middle of the ash residue pipe in the circumferential direction, so that the pressure of the upper part of the tank body and the pressure in the ash residue pipe can be balanced, the cooling water is prevented from being pressed into the fluidized bed gasification furnace when the pressure of the upper part of the tank body is greater than the pressure in the ash residue pipe, and the safety production is ensured; 6. the ash pipe comprises a straight pipe heat exchange section, an expanding pipe vaporization section and a straight pipe deslagging section which are sequentially communicated from top to bottom, wherein the diameters of the expanding pipe vaporization section and the straight pipe deslagging section are larger than that of the straight pipe heat exchange section, so that the diffusion of high-temperature ash in cooling water can be limited, the diffusion of fly ash which is not easy to dissolve in water in the ash can be limited, and the fly ash is forced to be wet; and the steam generated by the heat absorption of the cooling water is fully collected and enters the fluidized bed gasification furnace through the ash pipe to be used as a gasification agent, so that the investment cost of the gasification agent is reduced.

Description of the drawings:

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic structural diagram of a cold slag tank;

fig. 3 is a schematic structural view of the gas distribution pipe.

The slag cooling system comprises a cold slag tank 1, a slag collecting tank 2, a slag discharging tank 3, a slag pipe 4, a slag temperature sensor 5, a cooling water pipe 6, a water inlet pipe 7, a water inlet control valve 8, a cooling air pipe 9, an inflation pipe 10, an inflation control valve 11, a cold slag tank pressure sensor 12, a water balance valve 13, a first slag discharging valve 14, a pressure release valve 15, a slag discharging tank pressure sensor 16, a slag discharging liquid level sensor 17, a water injection valve 18, a second slag discharging valve 19, a slag discharging main pipe 20, a communicating pipe 21, a control valve 22, a slag flushing valve 23, a slag collecting tank flushing valve 24, a controller 25, a tank body 26, a gas distribution pipe 27, a high liquid level sensor 28, a balance hole 29, a low liquid level sensor 30, a manhole 31, an annular water distribution pipe 32, a water distribution hole 33, a straight pipe heat exchange section 34, an expanding pipe section 35, a straight pipe slag discharging section 36, a sintered metal filter element 37, a pipe body 38.

The specific implementation mode is as follows: