JPH02199195A - Temperature control apparatus for two-stage fluidized bed coal gasification furnace - Google Patents

Abstract

PURPOSE:To enable to suppress small changes in the compsn. of a formed gas caused by a remarkable change in an amt. of air and coal feed and to efficiently prevent gasification caused by the use of steam from decreasing by providing the first and the second controllers. CONSTITUTION:A deviation signal 17 made by reducing a temp. signal 7 of the second gasification furnace caused by a temp. setting signal of the furnace given by a function generator 9 in response to a load instruction signal 8 is input in a controller 10. On the other hand, depending on a coal feeding amt. signal 18, an air flow amt. signal made by a function generator 11 and an output correction signal are added together 12 and the value as it is output as an air flow rate 21 of the second gasification furnace to control the air flow rate to the second gasification furnace 1. When the deviation signal 17 is negative, it is input in a controller 13 by means of a switch 16 and when it is positive, a '0.0' signal output from a constant generator 16 is input in the controller 13. An output thereof is input in an upper and lower limiter 14 and the output serves as a steam flow rate instruction 22. Steam 15 fed in the second gasification furnace 1 controlled by the instruction 22 is a flow rate corresponding to the signal when the deviation signal is negative, and when it is positive, it is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a two-stage fluidized bed coal gasifier temperature control device.

[Conventional technology]

An example of a conventional device is shown in FIG.

In the second stage gasifier 01, which is an example of a conventional device shown in FIG. The solid fuel was reacted at high temperature with the produced gas supplied from the furnace 06, and converted into produced gas and char.

The control device shown in FIG.
The deviation between the second stage gasifier temperature setting value given by the function generator 09 in accordance with the second stage gasifier temperature 07 is determined and is input to the controller 0100. In addition, the air flow rate command given by the function generator 011 according to the input coal supply amount command 013 and the output correction signal outputted by the controller 010 are inputted to the adder 012 and added. It is output as the second stage gasifier air flow rate command 014.

Another example of the conventional device (pending application under Utility Model Application No. 125203 of 1988) is shown in Fig. 3.

In another example of the conventional device shown in FIG. 3, the second stage gasifier temperature control (a steam system is installed and the steam flow rate is the manipulated variable; Compared to an example of a conventional device, it is possible to operate the supply amount of air and coal according to the settings, and it is possible to suppress changes in the gas composition of the generated gas to a small extent.

The control device shown in FIG.
The deviation between the second stage gasifier temperature setting value given by the function generator 09 and the second stage gasifier temperature 07 is input to the controller 016, and the output of the controller 016 is set to the upper and lower limits. Enter 017, same upper and lower limit, 1 mitsuta 01
The output of 7 is used as the steam flow rate command 022, and the signal given by the function generator 011 according to the coal supply amount command 013 is input as the second stage gasifier air flow rate command 022.
He was 21.

[Problem to be solved by the invention]

An example of a conventional apparatus shown in FIG. 2 has the drawback that the air flow rate and coal supply amount change significantly during operation, resulting in large changes in the gas composition of the produced gas.

Another example of the conventional apparatus shown in FIG. 3 has the disadvantage that trapped steam normally flows in, reducing the gasification efficiency.

The present invention seeks to solve the above problems.

[Means to solve the problem]

The present invention includes a second stage gasifier to which coal, air, and steam are supplied from the outside, and to which generated gas is supplied from the first stage gasifier. , in a two-stage fluidized bed coal gasifier, a first controller that subtracts an in-furnace temperature signal of the second stage gasifier from a temperature set value signal corresponding to a load command and inputs a deviation signal; an adder that inputs an output correction signal from 1-, inputs an air flow rate signal corresponding to the coal supply amount, and outputs an air flow rate command signal; when the deviation signal is negative, the adder corresponds to the deviation signal; Outputs a steam flow rate command signal with zero flow rate!
Its special mission is to be equipped with an IG2 controller.

[Effect]

In the above, the temperature setpoint signal corresponding to the load command)
A deviation signal obtained by subtracting the furnace temperature signal of the second stage gasifier is input to the first controller, which outputs an output correction signal and an air flow rate signal corresponding to the coal supply amount. and the above output correction signal are input to the adder. The adder outputs an air flow command signal to control the flow rate of air supplied to the second stage gasifier.

Further, the deviation signal, if negative, is input to the second controller, which outputs a steam flow rate command signal corresponding to the deviation signal, and the steam flow rate command signal is inputted to the second controller. The amount of steam supplied to the two-stage gasifier is controlled so that the flow rate of steam supplied to the two-stage gasifier corresponds to the deviation value.

If the deviation signal is positive, the steam flow command signal stops the supply of steam.

According to the above, the temperature of the second stage gasifier is controlled by the supplied air flow rate below a predetermined temperature, and by the steam flow rate above a predetermined temperature. Changes in the composition of the generated gas caused by these changes can be kept to a minimum, and a decrease in gasification efficiency due to the use of steam can now be prevented.

〔Example〕

An embodiment of the present invention is shown in FIG.

In this embodiment shown in FIG. 1, coal 3 is connected from outside the fluidized bed 2Vc.
In a two-stage fluidized bed coal gasifier equipped with a second stage gasifier to which air 4 and steam 15 are supplied, and generated gas is supplied from the first stage gasifier 6 via an intermediate cyclone 5, the load command is A control in which the function generator 9 which inputs the signal 8 outputs the difference signal 17 obtained by subtracting the furnace temperature signal 7 of the second stage gasifier 1 from the second stage gasifier temperature set value signal! 10
．． The output correction signal and coal supply amount signal 18'f outputted by the controller 10! : Adder 12 which inputs and adds the air flow rate signal outputted by the constant function generator 11 and outputs the second stage gasifier air flow rate command signal 21; If negative, the KFi same deviation signal 17 is input to the controller 13, and if positive, the KFi same deviation signal 17 is input to the controller 13.
The switch 16 inputs the ``0,0° signal output from the constant generator 19 > inputs the output signal of control #513 into which the deviation signal 17 or the ``0.0'' signal is input, and outputs the steam flow rate command signal 22. It is equipped with an upper and lower limiter 14 for outputting.

In the above, the second stage gasifier temperature set value signal is given by the function generator 9 in response to the load command signal 8.
The deviation signal 17 from which the stage gasifier temperature signal 7 has been subtracted is input to the controller 10.

On the other hand, in response to the coal supply amount signal 18, the function generator adder 12 directly outputs the second stage gasifier air flow rate command 21.
The flow rate of air supplied to the second stage gasifier 1 is controlled.

Further, when the deviation signal 17 is negative, it is inputted to the controller 13 by the switch 16, and when it is positive, the 'o, o' signal outputted by the constant generator 16 is inputted to the controller 13. is input, and becomes the above side.

The gas supplied to the second stage gasifier IK controlled by the steam flow rate command 22 is a constant flow rate corresponding to the deviation signal when the deviation signal is negative, and a constant flow rate when the deviation signal is positive. will be stopped.

As a result of the above, the temperature of the second stage gasifier is controlled by the supplied air flow rate below a predetermined temperature, and by the steam flow rate above a predetermined temperature, resulting in significant layer changes in the air and coal supply amounts. This makes it possible to suppress changes in the composition of the produced gas caused by steam to a small extent, thereby preventing a decrease in gasification efficiency caused by the use of steam.

〔Effect of the invention〕

The present invention includes a first controller inputting a deviation signal obtained by subtracting a furnace temperature signal from a temperature set value signal, an air flow rate signal and a nine output correction signal outputted by the controller, and outputting an air flow rate command signal. By providing a second controller that outputs a steam flow rate command signal based on the deviation signal, when the temperature of the second stage gasifier is below a predetermined temperature, it is controlled by the supplied air flow rate, and At temperatures above , it is controlled by the steam flow rate, so changes in the composition of the produced gas caused by significant changes in the air and coal supply can be suppressed; It is now possible to prevent a decrease in gasification efficiency due to /c.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of one embodiment of the present invention, FIG. 2 is an explanatory diagram of an example of a conventional device, and FIG. 3 is an explanatory diagram of another example of the conventional device. 1... Second stage gasifier, 2... Fluidized bed, 3...
・Coal, 4... Air, 5... Intermediate cyclone, 6... First stage gasifier, 7... Furnace temperature signal, 8... Load command signal, 9... Function generation vessel,
10...Controller, 11...Function generator, 12.
...Adder, 13...Controller, 14...Upper/lower limiter, 15...Steam, 16...Switch, 17...Difference signal, 18...Coal supply signal, 19... ...Constant generator, 21...Air flow rate command signal, 22...Steam flow rate command signal.

Claims (1)

[Claims] Temperature set value corresponding to load command in a two-stage fluidized bed coal gasifier equipped with a second stage gasifier to which coal, air and steam are supplied from the outside and generated gas is supplied from the first stage gasifier. A first controller inputs a deviation signal obtained by subtracting the furnace temperature signal of the second stage gasifier from the signal, inputs an output correction signal from the controller, and inputs an air flow rate signal corresponding to the coal supply amount. It is characterized by comprising an adder that outputs an air flow rate command signal, and a second controller that outputs a steam flow rate command signal that corresponds to the deviation signal when the deviation signal is negative and has a zero flow rate when the deviation signal is positive. A two-stage fluidized bed coal gasifier temperature control device.