JP2015137293A - gasification furnace equipment and slag heat recovery method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recover a sensible heat of molten slag effectively.SOLUTION: A gasification furnace 8 where molten slag is provided by gasifying carbon content solid fuel, and a slag hopper 6 arranged in the bottom of the gasification furnace 8 are included. The molten slag is supplied to the slag hopper 6 from the gasification furnace 8 through a slag hole 10. The slag hopper 6 generates water vapor by heating slag water by the molten slag. The water vapor is supplied to the gasification furnace 8 through the slag hole 10, and used to gasification of the carbon content solid fuel. Such gasification furnace equipment 1 can recover sensible heat of the molten slag effectively by using the water vapor provided using the molten slag to gasification of the carbon content solid fuel.

Description

  The present invention relates to a gasification furnace apparatus and a slag heat recovery method, and more particularly to a gasification furnace apparatus and a slag heat recovery method used when gasifying coal.

  Gasification furnace facilities that gasify coal in a gasification furnace and generate fuel gas are known. The gasification furnace chamber is divided into two chambers, a combustor chamber and a reductor chamber, and pulverized coal and oxygen-enriched air are blown from the burner to cause a gasification reaction. The combustor chamber has a function of burning pulverized coal at a high temperature of about 1,800 degrees to generate a high-temperature heat source necessary for the gasification reaction in the reductor chamber and discharging coal ash as molten slag. The gasification furnace equipment is rapidly cooled and vitrified by dropping molten slag generated when coal is gasified into slag water maintained at a low temperature (for example, 70 ° C. to 80 ° C.). (See Patent Documents 1 and 2.)

JP 2007-255844 A JP-A-10-212487

  By cooling the molten slag, the high-temperature sensible heat of the molten slag has not been effectively utilized and has been discarded. Therefore, in view of the problems of the prior art, an object of the present invention is to propose a gasification furnace device that effectively recovers sensible heat of molten slag.

The subject of this invention is providing the gasification furnace apparatus and slag heat recovery method which collect | recover sensible heat of molten slag effectively.

  A gasification furnace apparatus according to the present invention includes a gasification furnace chamber for gasifying a carbon-containing solid fuel, a slag hopper from which molten slag generated by the gasification is discharged from the gasification furnace chamber through a slag hole, It has. At this time, the slag hopper generates steam by heating the slag water in the slag hopper by the sensible heat of the molten slag. The water vapor is supplied to the gasification furnace chamber through the slag hole.

  Such a gasification furnace device receives sensible heat from molten slag, vaporizes slag water, and supplies water vapor to the gasification furnace combustor through a slag hole at the bottom of the gasification furnace combustor. By using it as a part, it is possible to reduce the amount of oxidant supplied to the gasification furnace chamber from the outside in order to gasify the carbon-containing solid fuel, and to effectively recover the sensible heat of the molten slag To improve plant efficiency.

  The gasification furnace apparatus according to the present invention further includes a gasification furnace lower chamber vent valve that is disposed between the slag hole and the slag hopper and vents the gas inside the gasification furnace lower chamber.

  Such a gasification furnace apparatus reduces the internal pressure of the gasification furnace lower chamber using the gasification furnace lower chamber vent valve when the pressure of the gasification furnace lower chamber under the combustor becomes excessively high due to the evaporated water vapor. Thus, it is possible to prevent deterioration of the dischargeability of the molten slag in the slag hole.

  The gasification furnace apparatus according to the present invention further includes a lock hopper for storing the solidified slag in which the molten slag is solidified by the slag water, and a cooling device for cooling the solidified slag.

  In such a gasification furnace device, the slag water at the lower part of the gasification furnace always evaporates in a saturated state, but further, the inside of the lock hopper at the lower part is periodically released to atmospheric pressure, thus preventing the occurrence of flash. Therefore, it is desirable to maintain a low temperature. Therefore, a temperature rise in the lock hopper is prevented by providing a cooling device for cooling the solidified slag.

  The cooling device cools the solidified slag by cooling the lock hopper.

  Such a cooling device can prevent the solidified slag from adhering to the slag hole.

  The gasification furnace apparatus according to the present invention further includes a flush pipe for preventing the fluid vented from the inside of the lock hopper from flushing.

  Such a gasification furnace device can prevent the occurrence of flash when the solidified slag is taken out from the lock hopper by providing the flush pipe in the atmospheric discharge line for venting the gas inside the lock hopper. .

  The gasification furnace apparatus according to the present invention further includes a slag water supply device for supplying slag supply water to the slag hopper.

  Since such a gasification furnace device is provided with a slag water supply device that supplies makeup water to slag water that has decreased due to evaporation, it has the effect of preventing the turbidity of the slag water from increasing and maintaining the turbidity constant. The molten slag can be appropriately solidified.

  The gasification furnace apparatus according to the present invention further includes a slag water cooling system that cools the slag water taken out from the slag hopper and supplies the slag water to the slag hopper.

  Such a gasification furnace device has sufficient slag water when it is not necessary to supply water vapor from the slag hopper to the gasification furnace chamber, for example, when the carbon-containing solid fuel sufficiently contains water. By cooling to, the flow rate of water vapor supplied from the slag hopper to the gasification furnace chamber can be reduced.

  The slag heat recovery method according to the present invention uses the sensible heat of molten slag supplied from the gasification furnace chamber to the slag hopper through the slag hole, by gasifying the carbon-containing solid fuel in the gasification furnace chamber. Generating water vapor by heating the slag water stored in the slag hopper. At this time, the water vapor is supplied to the gasification furnace chamber through the slag hole and used for gasification as a part of the oxidant.

  According to such a slag heat recovery method, the gasifier apparatus receives sensible heat from the molten slag, raises the temperature of the slag water, generates water vapor, and flows to the combustor through the slag hole at the lower part of the gasifier combustor. Thereby, in order to gasify the carbon-containing solid fuel, the amount of the oxidant supplied to the gasification furnace chamber from the outside can be reduced. Thus, the plant efficiency is improved by effectively recovering the sensible heat of the molten slag.

  The gasification furnace apparatus and the slag heat recovery method according to the present invention receive sensible heat from the molten slag, raise the temperature of the slag water, and use the generated water vapor for gasification as part of the oxidizing agent. The sensible heat of the molten slag can be effectively recovered, and the plant efficiency is improved.

It is a block diagram which shows the gasification furnace apparatus in 1st Embodiment. It is a block diagram which shows the gasification furnace apparatus in 2nd Embodiment.

(First embodiment)
An embodiment of a gasifier apparatus will be described below with reference to the drawings. As shown in FIG. 1, the gasifier apparatus 1 in the first embodiment includes a gasifier 2 and a lock hopper 3. The gasification furnace 2 includes a slag hopper 6, a gasification furnace lower chamber 7, and a gasification furnace chamber 8 inside a pressure vessel 5. The slag hopper 6 is disposed at the lowermost part of the pressure vessel 5. The gasification furnace lower chamber 7 is disposed on the upper side of the slag hopper 6. The gasification furnace chamber 8 is disposed above the gasification furnace lower chamber 7. The gasification furnace chamber 8 has a slag hole 10 formed in the lower part.

  The gasification furnace chamber 8 is formed of a combustor chamber 11 and a reductor chamber 12. The combustor chamber 11 is disposed in the lower part of the gasification furnace chamber 8. The combustor chamber 11 is connected to the gasification furnace lower chamber 7 and the slag hopper 6 through the slag hole 10. The reductor chamber 12 is disposed at the upper part of the combustor chamber 11. The gasification furnace 2 includes a burner 14 and a burner 15. The burner 14 throws pulverized coal and oxygen-enriched air into the combustor chamber 11. The burner 15 puts pulverized coal into the reductor chamber 12.

  The gasification furnace 2 further includes a pressure gauge 17 and a gasification furnace lower chamber vent valve 18. The pressure gauge 17 measures the pressure in the gasification furnace lower chamber 7. The gasification furnace lower chamber vent valve 18 is provided in a flow path that connects the gasification furnace lower chamber 7 to the product gas pipe 19. The gasification furnace lower chamber vent valve 18 opens and closes the flow path connecting the gasification furnace lower chamber 7 to the product gas pipe 19 based on the pressure measured by the pressure gauge 17.

  The gasification furnace 2 further includes a slag water supply device 20. The slag water supply device 20 supplies slag water to the slag hopper 6.

  The lock hopper 3 is disposed at the lower part of the gasification furnace 2. The lock hopper 3 includes a slag discharge valve 21, a slag removal valve 22, a flush pipe 23, and a vent valve 24. The slag discharge valve 21 opens and closes a flow path that connects the slag hopper 6 to the lock hopper 3. The slag removal valve 22 opens and closes a flow path that connects the lock hopper 3 to external equipment. The vent valve 24 opens and closes an air release line that connects the lock hopper 3 to the air atmosphere. The flash pipe 23 is provided in the middle of the air release line that connects the lock hopper 3 to the air atmosphere. The flash pipe 23 prevents flashing when a high-pressure gas-liquid two-phase flow is released into the atmosphere through the atmosphere release line.

  The lock hopper 3 further includes a lock hopper water supply device 25. The lock hopper water supply device 25 supplies water to the lock hopper 3.

  The lock hopper 3 further includes a cooling pipe 26 and a lock hopper cooling device 27. The cooling pipe 26 is joined to the outside of the lock hopper 3 so as to be in thermal contact with the solidified slag stored in the lock hopper 3. The lock hopper cooling device 27 cools the solidified slag stored in the lock hopper 3 by supplying cold water to the cooling pipe 26.

  The embodiment of the slag heat recovery method is executed by using the gasifier apparatus 1. The gasification furnace apparatus 1 maintains the inside of the pressure vessel 5 of the gasification furnace 2 at a high pressure (for example, 3 MPa to 5 MPa), and stores slag water in the slag hopper 6. When the inside of the pressure vessel 5 of the gasification furnace 2 is maintained at 3 MPa to 5 MPa, the burner 14 supplies pulverized coal and oxygen-enriched air to the combustor chamber 11 of the gasification furnace chamber 8, and the burner 15 Supplies pulverized coal to the reductor chamber 12. The combustor chamber 11 of the gasification furnace chamber 8 burns pulverized coal at a high temperature using oxygen-enriched air. The reductor chamber 12 is gasified by blowing pulverized coal into the high-temperature gas rising from the combustor chamber 11, and lowers the gas temperature using the endothermic reaction of gasification. The produced gas produced by the gasification furnace chamber 8 is supplied to the next process equipment via the produced gas pipe 19.

  The gasification furnace chamber 8 further generates high-temperature (about 1800 ° C.) molten slag by gasifying pulverized coal. The gasification furnace chamber 8 discharges molten slag to the slag hopper 6 through the slag hole 10. When the molten slag is discharged to the slag hopper 6, it is cooled by the slag water stored in the slag hopper 6. The slag hopper 6 solidifies the molten slag by cooling the molten slag. The slag hopper 6 stores the solidified slag generated by solidifying the molten slag. The molten slag further heats the slag water by dropping into the slag water. That is, the conventional slag water cooling is abolished, and the slag hopper 6 heats the slag water using the molten slag, so that the slag water is heated to a saturation temperature (for example, 265 ° C. when the pressure vessel 5 has an internal pressure of 5 MPa). ) And actively generate water vapor. The water vapor fills the gasifier lower chamber 7 and is supplied to the gasifier chamber 8 through the slag hole 10. The gasification furnace chamber 8 gasifies pulverized coal by further using water vapor supplied through the slag hole 10.

  The gasification furnace device 1 can supply steam used for gasification of pulverized coal to the gasification furnace chamber 8 by generating steam using molten slag. The gasifier apparatus 1 can reduce the amount of oxidant supplied to the gasifier chamber 8 to gasify pulverized coal by supplying water vapor to the gasifier chamber 8. That is, the gasifier apparatus 1 can effectively recover the sensible heat of the molten slag by effectively using the water vapor generated using the molten slag, and can improve the plant efficiency.

  The pressure gauge 17 measures the pressure in the gasification furnace lower chamber 7. In the gasification furnace lower chamber vent valve 18, the pressure measured by the pressure gauge 17 is smaller than a predetermined threshold value (for example, 1 kPa) set so that the flow rate of the slag hole does not splash the molten slag flowing down. Sometimes, the flow path connecting the gasification furnace lower chamber 7 to the product gas pipe 19 is closed, and the flow path is opened when the pressure measured by the pressure gauge 17 is larger than a predetermined threshold value.

  The gasification furnace lower chamber 7 may become an excessively high pressure due to water vapor generated by the slag hopper 6. The molten slag generated by the gasifier lower chamber 7 is scattered and discharged by water vapor supplied to the gasifier chamber 8 through the slag hole 10 when the pressure of the gasifier lower chamber 7 is high. Sexuality may worsen. The gasifier apparatus 1 is supplied to the gasifier chamber 8 through the slag hole 10 by using the gasifier lower chamber vent valve 18 to prevent the pressure in the gasifier lower chamber 7 from increasing. It is possible to prevent the molten slag from being scattered by the water vapor and to prevent the molten slag from being discharged from the slag hole 10 from being deteriorated.

  The slag water supply device 20 supplies water to the slag hopper 6. The slag water stored in the slag hopper 6 is reduced by supplying water vapor to the gasification furnace chamber 8 through the slag hole 10. The slag water stored in the slag hopper 6 is increased in turbidity when molten slag is introduced. The gasification furnace apparatus 1 supplies water to the slag hopper 6 to prevent the lower end of the combustor chamber from being exposed on the water surface due to the reduction of the slag water, so that the slag water in the slag hopper 6 is less than a predetermined amount. If the concentration of slag water is excessively high, the slag water turbidity is set so that it does not cause clogging or wear of the equipment. Further, it is prevented from becoming larger than a predetermined value (for example, particle concentration 1 g / L).

The lock hopper 3 intermittently receives the solidified slag stored in the slag hopper 6 and supplies the solidified slag to an external device. That is, in the lock hopper 3, the slag discharge valve 21 is opened when the slag removal valve 22 is closed and the vent valve 24 is closed. The solidified slag stored in the slag hopper 6 is discharged to the lock hopper 3 and stored in the lock hopper 3 when the slag discharge valve 21 is opened.
The lock hopper cooling device 27 cools the lock hopper 3 by supplying cold water to the cooling pipe 26 so that the solidified slag stored in the lock hopper 3 becomes a predetermined temperature or less. In the gasifier 1, the slag water of the slag hopper 6 is always saturated and continues to evaporate. However, the inside of the lock hopper 3 at the lower part is periodically released to atmospheric pressure, so that flashing is prevented. It is desirable to keep the temperature low. Therefore, the gasification furnace device 1 is provided with the lock hopper cooling device 27 to prevent the temperature inside the lock hopper 3 from rising.

  In the lock hopper 3, the vent valve 24 is opened after the slag discharge valve 21 is closed. In the lock hopper 3, when the vent valve 24 is opened, the gas filled in the lock hopper 3 is released to the atmosphere through the flash pipe 23, and the internal pressure is reduced. When the inside of the lock hopper 3 is at a high temperature, a gas-liquid two-phase flow filled in the lock hopper 3 may be released to the air atmosphere and a flash may occur. The gasification furnace device 1 can prevent flashing by providing the flush pipe 23 in the air release line that connects the lock hopper 3 to the air atmosphere.

  The lock hopper water supply device 25 supplies water to the lock hopper 3. In the lock hopper 3, when the slag discharge valve 21 is closed and the vent valve 24 is closed, the slag removal valve 22 is opened. The solidified slag stored in the lock hopper 3 is supplied to equipment in the next process of the lock hopper 3 together with water supplied by the lock hopper water supply device 25 by opening the slag take-off valve 22.

(Second Embodiment)
FIG. 2 shows a gasifier apparatus in the second embodiment. The gasifier apparatus 30 is characterized in that the gasifier apparatus 1 in the first embodiment further includes a slag water cooling system 31. The slag water cooling system 31 includes a strainer 32, a slag water circulation pump 33, and a slag water cooler 34. The strainer 32 removes solid components from the slag water stored in the slag hopper 6. The slag water circulation pump 33 supplies the slag water from which the solid component has been removed by the strainer 32 to the slag water cooler 34. The slag water cooler 34 cools the slag water supplied from the slag water circulation pump 33, and supplies the cooled slag water after cooling to the slag hopper 6.

  The slag heat recovery method executed using the gasification furnace apparatus 30 includes an operation of gasifying using sensible heat of molten slag and an operation of gasifying without using sensible heat of molten slag. . The gasification operation using the sensible heat of the molten slag is performed in the same manner as the operation performed using the gasification furnace apparatus 1 in the first embodiment.

  The operation of gasifying without using the sensible heat of the molten slag is performed separately from the operation of gasifying using the sensible heat of the molten slag. In the gasification furnace device 30, the inside of the pressure vessel 5 of the gasification furnace 2 is maintained at a high pressure (for example, 3 MPa to 5 MPa), and the slag water cooling system 31 cools the slag water taken out from the slag hopper 6. By supplying the generated cooled slag water to the slag hopper 6, the slag water stored in the slag hopper 6 is maintained at a predetermined temperature (70 ° C. to 80 ° C.).

  The gasification furnace chamber 8 gasifies the pulverized coal supplied from the burner 14 and the burner 15 to generate product gas and generate molten slag. The gasification furnace chamber 8 discharges molten slag to the slag hopper 6 through the slag hole 10. When the molten slag is discharged to the slag hopper 6, it is cooled and solidified by the slag water stored in the slag hopper 6. The slag water is heated by introducing molten slag.

  At this time, the amount of water vapor supplied from the slag hopper 6 to the gasification furnace chamber 8 through the slag hole 10 is such that the slag water is sufficiently cooled to a low temperature by the slag water cooling system 31. Less when compared to when the operation of gasifying using heat is performed. Therefore, the amount of slag water stored in the slag hopper 6 is reduced, and the slag water replenishing device 20 does not need to supply much water to the slag hopper 6 and gasifies using the sensible heat of the molten slag. A smaller amount of water is supplied to the slag hopper 6 compared to when the operation is performed.

  The lock hopper 3 intermittently receives the solidified slag stored in the slag hopper 6 and supplies the solidified slag to an external device. At this time, since the solidified slag discharged to the lock hopper 3 is sufficiently low in temperature, the gasification furnace device 30 does not need to cool the lock hopper 3 by the lock hopper cooling device 27, and the sensible heat of the molten slag. Compared with the case where the operation of gasifying using is performed, the solidified slag can be supplied to an external device at a low cost.

  The gasification furnace device 30 switches between gasification using the sensible heat of the molten slag and gasification without using the sensible heat of the molten slag based on the moisture contained in the pulverized coal. The various pulverized coals can be appropriately gasified with high efficiency. For example, when the pulverized coal sufficiently contains water, the gasification furnace apparatus 30 performs an operation of gasification without using sensible heat of molten slag, thereby causing the gasification furnace chamber 30 to be gasified from the slag hopper 6. The flow rate of the water vapor supplied to 8 can be reduced, and the pulverized coal can be appropriately gasified. The gasification furnace device 30 uses the sensible heat of the molten slag by performing an operation of gasifying using the sensible heat of the molten slag when the amount of water contained in the pulverized coal is sufficiently small. The generated steam is supplied to the gasification furnace chamber 8 and the amount of oxidant supplied to the gasification furnace chamber for gasifying the pulverized coal can be reduced, and the sensible heat of the molten slag is effective. Can be recovered.

  The lock hopper cooling device 27 can be replaced with another cooling device that cools the solidified slag stored in the lock hopper 3 without using the cooling pipe 26. Examples of such a cooling device include a circulation type cooling device that takes out slag water from the lock hopper 3 and cools it, and then returns it to the lock hopper 3, and an air cooling fin that is joined to the outer surface of the lock hopper 3 and air-cooled. The gasifier apparatus to which such a cooling device is applied can also effectively recover the sensible heat of the molten slag in the same manner as the gasifier apparatuses 1 and 30 in the first embodiment or the second embodiment. And can prevent flashing. Further, the lock hopper cooling device 27 can be omitted when there is no fear of flushing. At this time, the gasifier apparatus in which the lock hopper cooling device 27 is omitted is also the sensible heat of the molten slag in the same manner as the gasifier apparatuses 1 and 30 in the first embodiment or the second embodiment. Can be recovered effectively.

1: Gasification furnace device 2: Gasification furnace 3: Lock hopper 6: Slag hopper 7: Gasification furnace lower chamber 8: Gasification furnace chamber 10: Slag hall 17: Pressure gauge 18: Gasification furnace lower chamber vent valve 19: Generated gas pipe 20: Slag water supply device 21: Slag discharge valve 22: Slag discharge valve 23: Flush pipe 24: Vent valve 25: Lock hopper water supply device 26: Cooling pipe 27: Lock hopper cooling device 30: Gasifier device 31 : Slag water cooling system

Claims (8)

A gasification furnace chamber for gasifying carbon-containing solid fuel;
The molten slag generated by the gasification includes a slag hopper that is discharged from the gasification furnace chamber through a slag hole,
The slag hopper generates steam by heating the slag water in the slag hopper by sensible heat of the molten slag,
The gasifier apparatus in which the water vapor is supplied to the gasifier chamber through the slag hole.   The gasification furnace apparatus according to claim 1, further comprising a gasification furnace lower chamber vent valve disposed between the slag hole and the slag hopper and venting a gas inside the gasification furnace lower chamber. A lock hopper for storing the solidified slag in which the molten slag is solidified by the slag water;
The gasification furnace apparatus described in Claim 1 further equipped with the cooling device which cools the said solidification slag.   The gasifier apparatus according to claim 3, wherein the cooling device cools the solidified slag by cooling the lock hopper.   The gasifier apparatus according to claim 3, further comprising a flush pipe for preventing fluid vented from the inside of the lock hopper from flushing.   The gasifier apparatus according to claim 1, further comprising a slag water supply device that supplies slag supply water to the slag hopper.   The gasifier apparatus described in Claim 1 further provided with the slag water cooling system which cools the slag water taken out from the said slag hopper, and supplies it to the said slag hopper. Gasifying carbon-containing solid fuel in the gasifier chamber;
Generating steam by heating slag water stored in the slag hopper using sensible heat of molten slag supplied from the gasification furnace chamber to the slag hopper via the slag hole,
The said water vapor | steam is supplied to the said gasification furnace chamber through the said slag hole, and is a slag heat recovery method utilized for gasification as a part of oxidizing agent.

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