JPS6025608B2 - Reactor gas energy recovery power generation system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reactor gas energy recovery power generation system that recovers reactor gas energy to generate electricity.

This type of system has a structure in which the gas coming out of the reactor is sent to the turbine generator through a gas cleaning device and a turbine control valve, and a septum valve is connected in parallel with the turbine generator. However, gas cleaning equipment only had a cleaning (dust collection) function.

During power generation operation, the top pressure of the reactor was controlled by operating a septum valve. In such a system configuration, it is difficult to stabilize the furnace top pressure, and the differential pressure across the gas cleaning device cannot be properly maintained, resulting in the inconvenience that the gas cleaning effect cannot be fully demonstrated. It just happened. SUMMARY OF THE INVENTION An object of the present invention is to provide a reactor gas energy recovery power generation system that can solve the above-mentioned problems and reliably maintain both a stable furnace pressure and a good gas cleaning effect.

However, the main feature of the system according to the present invention is that the gas cleaning device is provided with a flow rate adjustment operation section, and by operating the flow rate adjustment operation section during power generation operation, the pressure difference between the front and rear of the gas cleaning device can be maintained at a good level. The top pressure of the reactor is controlled by operating the regulating valve of the turbine generator while controlling the pressure so as to obtain a cleaning effect. Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

This embodiment is a blast furnace exhaust gas energy recovery power generation system, in which 1 is a blast furnace blower, 2 is a hot blast furnace, 3 is a blast furnace, 4 is a dust catcher, 5 is a gas cleaning device with a built-in flow rate adjustment operation unit, and 6 is a turbine inlet valve. , 7 is a main blocking valve, 8 is a turbine control valve, 9 is a turbine that drives the generator 10, 11 is a turbine outlet stop valve, and 12, 13, and 14 are bypass valves parallel to the gas flow path of the turbine 9. It is a septum valve provided in the valve 12 is a control valve, valve 13 is a range valve and valve 14
is called a manual valve.

15 is a gas holder, 16 is a blast furnace furnace top pressure detector, 17 is a turbine inlet pressure detector, 18 is a differential pressure detector before and after the gas cleaning device 5, 19 is a turbine rotation speed detector, and 20 is a generator output detector. be.

Reference numeral 21 denotes a gas flow rate control device that receives output signals from the detectors 16 and 18 and operates the flow rate adjustment operation section of the gas cleaning device 5;
2 receives the output signal of the detector 17 and operates the septum valve 12,1.
A septum valve control device operates 3 and 14, and 23 is a turbine governor that operates a turbine speed regulating valve in response to output signals from detectors 16, 19 and 20.

24 is for each device 2 depending on the system status and external conditions.
1, 22, 23, and 24; and 25 and 26, a furnace top pressure setting device that provides the gas flow rate control device 21 with a furnace top pressure setting value and a differential pressure setting value before and after the gas cleaning device, respectively; A front and rear differential pressure setting device, 27, a turbine inlet pressure setting device that provides a turbine inlet pressure setting value to the septum valve control device 22, and 28, 29, and 30, a load control value and a turbine rotation value to the turbine governor 23, respectively. This is a setting device for setting the number and maximum output of the generator.

In said system, the turbine 9 is operated only when the blast furnace 3 is in stable high pressure operating conditions.

Therefore, when starting up the blast furnace operation and during the wind shutdown operation, the septum valves 12, 13, and 14 are fully opened to allow all of the blast furnace generated gas to bypass the turbine 9. At this time, the blast furnace top pressure is controlled to be constant by operating the flow rate adjustment operation section of the gas cleaning device 5 with the gas flow rate control device 21. Also, while the turbine 9 is operating, the septum valves 12, 1
3 and 14 are completely closed, and all the gas generated from the blast furnace 3 is transferred to the evening bin 9.
flow to. In this case, the furnace top pressure of the blast furnace 3 is controlled by operating the turbine control valve 8 with the turbine governor 23,
Further, by operating the flow rate adjustment operation section of the gas cleaning device 5 with the gas flow rate control device 21, a pressure difference between the front and rear of the gas cleaning device is maintained such that the dust-generating effect can be achieved. The septum valve control device 22 operates the control valve 12 in cooperation with the gas flow rate control device 21 to start the turbine 9 without causing any disturbance to the blast furnace system.

Also, even during continuous turbine operation, the septum valve control device 22
backs up the gas flow rate control device 21, prevents excessive rise in furnace top pressure in abnormal situations such as blow-through of the blast furnace 3, load interruption of the generator 9, and turbine trip, and ensures stable blast furnace operation. Next, the operation of the system of this embodiment will be explained in more detail.

(1) Normal operation 01 turbine drive: control valve 12 and hinge valve 13, each operated by the turbine inlet pressure regulator output and on/off signal from the septum valve control device 22;
Furthermore, all the manual valves are fully opened when the turbine is inactive, allowing all blast furnace gas to bypass the turbine 9 and lowering the outlet pressure of the gas cleaning device 5 as much as possible.

The furnace top pressure at this time is controlled by the gas flow rate control device 21. In other words, the gas flow rate control device 21 is operating in the furnace top pressure control mode. When a turbine start command is issued in this state, the turbine inlet valve 6 and the turbine outlet valve 11 are opened to allow turbine gas to flow in preparation for starting the turbine, and then the main blocking valve 7 is opened.

Next, close the manual valve 14 and close the turbine inlet pressure setting device 2.
7 to raise the turbine inlet pressure (or gas cleaning device outlet pressure) to a value (turbine starting pressure) required to maintain the no-load rated rotational speed of the turbine 9. Next, the load limit setting device 28 is operated to gradually accelerate the turbine 9, and the rotation speed setting device 29 is operated to perform a synchronization operation when the generator 10 is synchronized with the outside power frequency, thereby bringing the system into line with the outside power. Enter. When the generator 10 is connected to outside power, the general control device 24 releases the suppression of the differential pressure control function of the gas flow rate control device 21 and the furnace top pressure control function of the turbine governor 23, which had been suppressed until then. } Load removal: Operate the turbine inlet pressure setting device 27 to the pressure increasing side, and change the turbine inlet pressure setting value from the furnace top pressure setting value set by the furnace pressure setting device 25 to the gas cleaning of the gas flow rate control device 21. It is set to a value slightly higher than the value obtained by subtracting the set value set by the front and rear differential pressure setter 26 for the mounting hawk 5.

As the control valve 12 is closed by this operation (the range valve 13 is closed), the turbine inlet pressure increases accordingly, and the differential pressure across the gas cleaning device 5 decreases. automatically shifts from furnace top pressure control mode to reed pressure control mode. In this way, the gas flow rate control device 21 operates the flow rate adjusting operation section of the gas cleaning device 5, and the minimum differential pressure across the gas cleaning device 5 required to obtain a good dust removal effect is ensured. At the same time, the furnace top pressure control function of the turbine governor 23 is automatically activated to operate the turbine control valve 8, and the furnace top pressure is controlled to a constant value. In this state, the entire amount of gas flows to the turbine 9. '3' Turbine stop: When the turbine inlet pressure setting device G is operated to the pressure lowering side along with the turbine stop command, the control valve 12 is gradually opened.
The turbine inlet pressure decreases accordingly.

Due to this pressure drop, the gas flow rate control device 21 automatically shifts to the furnace top pressure control mode, and causes the gas cleaning device 5 to perform furnace top pressure control. Similarly, the mode of the turbine governor 23 shifts from furnace pressure control to rotation speed control, and the generator 10 is disconnected from the external power. After the control valve 12 is further opened and fully opened, the main blocking valve 7 is closed to stop the turbine 9. The general control device 24 controls the differential pressure control function of the gas flow rate control device 21 and the turbine governor 2 at the same time as the scale row of the generator 10.
3. Suppresses the furnace top pressure control function. (0) Emergency operation'1) Turbine trip and load shedding: In this case,
The generator 10 is disconnected from the external power and the turbine adjustment valve 8 is immediately closed.

When the general control device 24 receives a turbine trip or load cutoff signal, it switches the mode of the gas flow rate control device 21 to the furnace top pressure control mode, and also switches the mode of the gas flow rate control device 21 to the furnace top pressure control mode.
The septum valve control device is commanded to lower the turbine inlet pressure set value for No. 2 to the turbine starting pressure, open the range valve 13, and operate the feed forward compensation circuit. Note that the septum valve control device 22 maintains the turbine inlet pressure at the turbine starting pressure by controlling the control valve 12 and the engine valve 13 at the same time as an abnormal condition occurs.
When both are fully opened, the outlet pressure of the gas scrubbing device 5 drops rapidly, and the gas flow rate control device 21 not only temporarily loses its top pressure control function, but also the outlet side of the gas scrubbing device 5 and the turbine 9
This is because there is a danger that the gas accumulated in the gas flow path between the gas flow path and the gas flow path will be instantaneously released toward the gas holder 15, and the pressure in the gas flow path leading to the inlet side of the gas holder 15 will rise excessively. ■ Blast furnace blow-through: When the blast furnace 3 causes blow-through during turbine operation and as a result, a large amount of blast furnace gas instantly flows into the turbine 9 side, the septum valve control device 22 detects a sudden rise in the turbine inlet pressure and The valves 12 and 13 are operated as internal safety valves to reduce the number of times the bleater installed in the blast furnace 3 blows.

As is clear from the above, according to the present invention, the differential pressure between the front and rear of the gas cleaning device can be appropriately controlled and a good cleaning effect can be ensured, making it possible to eliminate the need for an electric precipitator, etc., which was conventionally attached. In addition, the reactant gas discharged from the gas cleaning device is not bypassed by the septum valve and the entire amount drives the turbine generator, effectively utilizing the energy possessed by the reactant gas while controlling the furnace top pressure with the turbine governor valve. The furnace top pressure can be controlled stably.
Furthermore, it is possible to achieve great effects such as improved energy recovery efficiency.

As mentioned above, the present invention can be applied to the blast furnace system of a steelmaking plant and achieve remarkable effects, but it can also be applied to various systems including chemical reaction tanks that discharge high-pressure gas containing a large amount of general dust. Needless to say, it can be applied effectively and effectively.

[Brief explanation of the drawing]

The figure shows an embodiment of the reactor gas energy recovery power generation system according to the present invention. 3... Blast furnace, 5... Gas cleaning device with flow rate adjustment operation section, 8... Turbine tuning valve, 9
... Turbine, 10... Generator, 12,1
3, 14... Septum valve, 16... Furnace top pressure detector, 17... Turbine inlet pressure detector, 18... Gas cleaning device front and back difference Pressure detector, 2
1...Gas flow control device, 22...Septum valve control device, 23...Evening bin governor, 24...
General control device.

Claims (1)

[Claims] 1 Equipped with a gas cleaning device having a cleaning section that cleans gas discharged from the reactor and a flow rate adjustment operation section that adjusts the gas flow rate, one side of which passes the gas from the gas cleaning device through a septum valve, The other is a gas flow rate control device that controls the gas flow rate of the gas cleaning device and a gas flow rate control device that controls the septum valve in a reactor gas energy recovery power generation plant in which the gas is discharged through a turbine generator equipped with a turbine regulating valve at its input. Collectively commands the septum valve control device, the turbine governor that operates the turbine regulating valve, the gas flow rate control device, the septum valve control device, and the turbine governor to change the operating state or switch the control mode based on an abnormal signal. A general control device is provided, and during normal power generation operation, the gas flow rate control device operates the flow rate adjustment operation section of the gas cleaning device to control the differential pressure across the gas cleaning device, and
operating a turbine regulating valve by the turbine governor;
In addition to operating the reactor by controlling the top pressure of the reactor, the septum control device is placed in a standby state in order to operate the septum valve in response to an abnormality in the reactor or turbine generator, and when the turbine generator is not in power generation operation. In this case, the reactor gas energy recovery power generation system is characterized in that the gas flow rate control device is operated by controlling the top pressure of the reactor by operating a flow rate adjustment operation section of the gas cleaning device.