JPH0774342B2 - Method for detecting abnormal coal supply in coal gasifier - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the supply of coal, and more particularly, to a coal gasification apparatus that is public in order to detect abnormalities in the amount of coal supplied to a coal gasification furnace and maintain stable operation. The present invention relates to a coal supply abnormality detection method.

[0002]

2. Description of the Related Art As a conventional coal gasifier, Japanese Patent Application Laid-Open No. 57-47748 is known, but as shown in FIG. 5, coal stored in the atmospheric hopper 2 is periodically charged. By opening the sluice valve 20, the lock hopper 3 is charged. At this time, the pressure in the lock hopper 3 is kept the same as that in the normal pressure hopper 2 by releasing the gas in the lock hopper 3 by opening the release valve 22. When the supply of coal from the normal pressure hopper 2 is completed, the sluice valve 20 and the discharge valve 22 are closed and the pressurizing valve 23 is opened to supply the high pressure gas to the lock hopper 3 to increase the pressure of the lock hopper 3. When the pressure of the lock hopper 3 becomes the same as the pressure of the supply hopper 4, the pressurizing valve 23 is closed. The amount of coal in the supply hopper 4 is detected by the load cell 5, and when the amount of coal falls below a certain value, the pressure equalizing valve 24 and the sluice valve 21 are opened to supply coal to the supply hopper 4. When the supply of coal is completed, the pressure equalizing valve 24 and the sluice valve 21 are closed, and these operations are periodically repeated.

In order to stably supply coal to the coal gasification furnace 12, a high pressure pressure adjusting gas 7 is supplied to the supply hopper 4 so as to maintain the pressure higher than that of the coal gasification furnace 12. The pressure is adjusted by the pressure gauge and the pressure adjusting valve 9.
In order to keep the amount of coal supplied to the coal gasifier 12 constant, the weight of the supply hopper 4 is constantly measured by the load cell 5,
The coal supply amount is calculated from the change over time of the weight, and the rotation speed of the rotary feeder 6 is controlled according to the coal supply amount.

A fluidizing gas 8 is supplied from the bottom of the supply hopper 4 to prevent the coal stored in the supply hopper 4 from sticking, and the fluidizing gas 8 is used as a coal fluidizing medium. Therefore, the pressure adjusting gas 7 and the fluidizing gas 8 are supplied to the supply hopper 4, but in general, powder adheres in the supply hopper to form a coal bridge, and the discharge from the supply hopper occurs. The phenomenon of poor performance is well known.

In a spouted bed type coal gasification furnace, if such a state where coal is not supplied continues for a long time, the temperature in the coal gasification furnace lowers and the temperature of the slag becomes lower than the melting point. It may solidify and gradually block the slag tap in the gasification section, which may stop the operation of the coal gasification furnace. For this reason, coal gasifiers usually have
When the temperature of the gasification section drops, the temperature inside the furnace is forced to
A heating burner 13 is installed to raise the temperature to the temperature required to keep the slag molten. However, since the temperature of the gasification section exceeds one thousand and several hundred degrees Celsius, it is difficult to directly measure the temperature, and the temperature of the gasification section is usually estimated from the temperature of the gas leaving the coal gasification furnace. Therefore, the heating burner 1
There will be a time delay before the start of operation in No. 3. In addition, it is uneconomical to keep the temperature-raising burner 13 constantly operating, and the temperature of the gasification section is raised more than necessary.

Therefore, for stable operation of the coal gasifier,
It is important to detect the temperature decrease in the gasification section earlier, in other words, to detect the decrease in coal supply rate earlier.

In the conventional coal supply abnormality detection method,
The decrease in the coal supply amount is detected by a decrease in the measured value of the load cell 5 over time, and a decrease in the differential pressure of the coal carrier gas 10 in the coal carrier pipe 11, but in the load cell 5, the supply hopper is detected. No. 4, the weight of coal is measured, the measured value is likely to fluctuate due to the pressure fluctuation of the supply hopper 4, and the variation width of the weight is very small, and the coal transfer pipe 11 has Regarding the differential pressure, there is pulsation and the like, and it cannot be said that it is sufficiently reliable to control the operation of the temperature rising burner 13 based on these detection results.

[0008]

In the conventional coal supply abnormality detecting device of the coal gasifier, the decrease in the coal supply amount is detected by the differential pressure in the coal conveying pipe, but the pressure fluctuation of the supply hopper is detected. Causes the measured value to fluctuate. Further, although the temperature decrease of the coal gasification furnace was measured by the temperature of the exhaust gas, there was a problem that the operation of the temperature raising burner was delayed.

An object of the present invention is to provide a method for detecting abnormal coal supply in a coal gasifier which can detect early a decrease in the amount of coal supplied to a coal gasification furnace in order to improve the reliability of operation control of a temperature rising burner. To provide.

[0010]

In order to achieve the above-mentioned object, a method for detecting abnormal coal supply of a coal gasifier according to the present invention comprises introducing coal into a lock hopper and then introducing pressurized gas to boost the pressure. , Introducing pressure adjusting gas and fluidizing gas into the supply hopper to adjust the pressure and fluidizing the input coal, carried out from the supply hopper and supplied to the coal gasifier by the coal supply gas. In a coal supply abnormality detection method for a coal gasifier that detects a coal supply amount, a pressure adjusting gas and a fluidizing gas having a composition different from that of the coal supplying gas are used, and the pressure adjusting gas and the fluidizing gas in the coal supplying gas are used. The concentration of the component of the working gas is detected, and the decrease in the supply amount is detected by the increase in the concentration.

Then, a part of the produced gas produced in the coal gasification furnace is used as the coal supply gas, and is separated from the produced gas into the pressurized gas of the lock hopper, the pressure adjusting gas of the supply hopper and the fluidizing gas. It is also configured to use a part of carbon dioxide.

[0012]

According to the method for detecting abnormal coal supply of the coal gasifier of the present invention, when the coal is stably supplied from the supply hopper to the coal gasification furnace via the lock hopper, the supply hopper is powdered. There is little outflow of the pressure adjusting gas and the fluidizing gas into the coal-conveying pipe that is body-sealed, but the outflow of these gases increases when the coal bridge begins to form in the supply hopper. Therefore, by changing the composition of the pressure adjusting gas and the fluidizing gas supplied to the supply hopper with the composition of the coal supplying gas, the concentrations of the components of the pressure adjusting and fluidizing gas in the coal supplying gas in the coal conveying pipe are changed. Is detected and the decrease in the coal supply amount is detected early from the increase in the concentration, the operation of the temperature rising burner inserted in the coal gasification furnace is started.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG.

As an example, as in the plant for producing hydrogen by the coal gasifier shown in FIG. 1, coal is charged into the lock hopper 3 from the atmospheric hopper 2 through the sluice valve 20, and then pressurized gas is added. It is introduced from the pressure valve 23 to increase the pressure, and the pressure adjusting gas 7 and the fluidizing gas 8 are introduced into the supply hopper 4 to adjust the pressure, and the coal fed is fluidized and discharged from the supply hopper 4. And coal supply gas 1
A method for detecting an abnormal coal supply of a coal gasifier for detecting the supply of coal supplied to a coal gasification furnace 12 according to 0, which comprises a pressure adjusting gas 7 having a composition different from that of the coal supply gas 10.
And the fluidizing gas 8 are used to detect the concentrations of the components of the pressure adjusting gas 7 and the fluidizing gas 8 in the coal supply gas 10, and the decrease in the coal supply is detected by the increase in the concentration.

The gas produced in the coal gasification furnace 12 is cooled and guided to the desulfurization device 15, where H ₂ S and COS contained in the gas.
And other sulfur compounds are removed. The desulfurized product gas is
A part of the pressure is boosted by the compressor 18, and the coal gasifier 1
Used as coal feed gas 10 The remaining product gas is guided to the CO conversion device 30, and carbon monoxide in the product gas is converted into hydrogen and carbon dioxide. Further, the produced gas is guided to a decarbonation device 31, where carbon dioxide is removed, and a product hydrogen gas 19 is obtained. A part of the carbon dioxide 16 separated and removed by the decarbonator 31 is pressurized by the compressor 17, and the pressurized gas of the lock hopper 3 for coal supply, the pressure adjusting gas 7 of the supply hopper 4 and the fluidization of coal are used. Used as gas 8. Further, the carbon dioxide concentration in the coal transport pipe 11 is measured by the densitometer 14.

Next, the operation of the present invention will be described with reference to FIGS.

When coal is stably supplied from the supply hopper, the rotary feeder 6 is sealed with powder as shown in FIG. 2, so that the pressure is supplied to the supply hopper 4 for fluidization and fluidization. The gases 7 and 8 rarely flow into the coal transport pipe 11.

On the other hand, when the coal bridge is started to be formed in the supply hopper 4, the amount of coal discharged through the rotary feeder 6 decreases and the pressure adjusting and fluidizing gas 7, 8 supplied to the supply hopper 4 is reduced. Is the rotary feeder 6
And the amount flowing out to the coal transport pipe 11 increases,
When the coal bridge is completely formed, only the pressure adjusting and fluidizing gases 7 and 8 pass through the rotary feeder 6, as shown in FIGS. 3 and 4. in this case,
The amount of each gas 7 and 8 passing through the rotary feeder 6 is about half the amount of the coal supply gas 10.

The gas produced in the spouted bed type coal gasification furnace contains carbon dioxide of about 5% or less, though it varies depending on the properties of the coal. It does not increase. Therefore, the carbon dioxide contained in the coal supply gas 10 is 5% at most. On the other hand, the concentration of carbon dioxide 16 separated and removed by the carbon dioxide removal device 15 is usually 90% or more.

Therefore, the coal is stabilized and the coal gasifier 12
Carbon dioxide in the coal transport pipe 11 is 5% or less, the carbon dioxide concentration in the coal transport pipe 11 starts to rise and starts to form a coal bridge in the supply hopper 4. When coal bridges are formed, the concentration rises to about 40%.

That is, the carbon dioxide in the coal conveying pipe 11 is continuously measured by the densitometer 14, and the change in the concentration is observed to decrease the coal supply amount due to a coal bridge or the like, and the temperature of the gasification section caused by the decrease. It becomes possible to detect the decrease accurately and quickly. By detecting this increase in the concentration, the temperature rising burner 13 of the coal gasification furnace 12 is operated automatically or at the operator's discretion. At the same time
The coal bridge of the feed hopper 4 is collapsed by a mechanical operation such as a vibrator or hammering. Performing this operation at the time of stable coal supply has the opposite effect because it compacts the coal rather, and it is effective to perform this operation at the initial stage when the coal bridge begins to form. By detecting the increase in the concentration of carbon dioxide in the coal supply gas 10, this mechanical operation can be performed quickly.

Another advantage of the present invention is that by using the produced gas for the coal feed gas 10 and the carbon dioxide separated from the produced gas for the respective gases 7, 8 of the feed hopper 4,
Even when the supply hopper 4 forms a coal bridge, in the coal supply gas, that is, in the produced gas, a gas that is not normally contained in the produced gas, or a gas such as nitrogen that is difficult to separate from the produced gas. Is not mixed, the introduction of gas from other than the coal gasifier system is not necessary, and further, since the gas released from the lock hopper is carbon dioxide, it can be released to the atmosphere as it is.

As another embodiment of the present invention, an example of the process for producing hydrogen from the product gas of the coal gasifier is shown, but the process of producing the syngas from the product gas of the coal gasifier or the fuel cell. In the process of generating power by means of the above, the same effect can be obtained by supplying the carbon dioxide separated and removed in the process to the supply hopper.

[0024]

According to the method for detecting abnormal coal supply of the coal gasifier of the present invention, the decrease in the amount of supplied coal can be detected at an early stage by detecting the concentration of the coal supplied gas. The stable operation of the furnace can be maintained for a long period of time.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of the present invention.

FIG. 3 is a diagram for explaining the operation of the present invention.

FIG. 4 is a diagram illustrating the operation of the present invention.

FIG. 5 is a diagram showing a conventional technique.

[Explanation of reference numerals] 3 lock hopper 4 supply hopper 7 pressure adjusting gas 8 fluidizing gas 10 coal carrier gas 11 coal carrier pipe 12 coal gasifier

Claims (2)

[Claims] 1. A coal hopper is charged into a lock hopper, a pressurized gas is then introduced to increase the pressure, and a pressure adjusting gas and a fluidizing gas are introduced into a supply hopper to adjust the pressure and to charge the coal. In a coal supply abnormality detection method of a coal gasifier that fluidizes and detects the supply amount of the coal that is carried out from the supply hopper and supplied to the coal gasification furnace by the coal supply gas, different from the coal supply gas. Using the pressure adjusting gas and the fluidizing gas of the composition,
Coal supply abnormality of a coal gasifier characterized by detecting the concentrations of the components of the pressure adjusting gas and the fluidizing gas in the coal supply gas, and detecting the decrease in the supply amount by increasing the concentration. Detection method. 2. A part of the produced gas produced in the coal gasification furnace is used as the coal supply gas, and the pressurized gas of the lock hopper is used,
2. The method for detecting abnormal coal supply in a coal gasifier according to claim 1, wherein a part of carbon dioxide separated from the generated gas is used as a pressure adjusting gas and a fluidizing gas of a supply hopper.