JPS5950855B2 - Control method for top pressure recovery turbine power generation equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling a furnace top pressure recovery turbine power generation equipment, and in the event of a power outage in the power system, the blast furnace blower stops blowing air to the blast furnace, lowers the set pressure of the blast furnace, and maintains the low pressure. The purpose is to avoid generation of excessive safety power when the power generation equipment is driven by blast furnace gas and the power recovered by the furnace top pressure recovery turbine is used as power for safety of the blast furnace.

Traditionally, this safety power has been supplied by separate equipment, but since steelworks are generally equipped with multiple blast furnaces, it is necessary for one safety power supply facility to cover the safety power for all blast furnaces. For example, in addition to the high cost of laying power transmission lines, it is also necessary to increase the amount of power normally transmitted by private power generation equipment (generally not highly efficient) used to secure power for security, which is undesirable from the point of view of energy consumption.

In the event of a power outage in the power system, the main sources of power for blast furnace safety are the water pump for cooling the blast furnace body and the water pump for cooling the hot air valve, which generally require about 500 to 4000 KW of power.

Furthermore, if a furnace top pressure recovery turbine power generation facility is installed to recover energy from blast furnace gas, the maximum output will be 2 times the amount of power used for safety, although there will be considerable differences depending on the capacity and pressure of the blast furnace.
~5 times as much is obtained.

For example, when the power system is out of power and the top pressure recovery turbine power generation equipment's power supply to the power transmission system is cut off, if the generated output is used for safety power, the excess power obtained for safety could create a dangerous situation. It may become.

The present invention is intended to avoid such a situation, and one embodiment thereof will be described below based on the drawings.

A blast furnace blower 2 that supplies air to the blast furnace 1 is driven by an electric motor 3 and blows air to the blast furnace 1 through an on-off valve 4 and a hot stove 5.

Blast furnace gas discharged from the blast furnace 1 is removed with coarse particles, for example, by a dust catcher 6, then fine particles are removed by, for example, a bag filter 7, and passed through a bypass control valve 8 to a gas holder 9.
guided by.

On the other hand, a turbine 10 of the top pressure recovery turbine power generation equipment is connected in parallel to a bypass control valve 8 via a flow control valve 11, and a generator 12 driven by the turbine 10 sends its output through a circuit breaker 13 to the main power transmission system 14. is supplied to

The furnace top pressure of the blast furnace 1 when the turbine 10 is not used is controlled by the bypass control valve 8, and the flow rate control valve 11 is fully closed.

Furthermore, when the turbine 10 is used, the top pressure of the blast furnace 1 is controlled by the flow rate control valve 11, and the bypass control valve 8 is kept in a fully closed state or close to it. Sometimes it is additionally used to control the furnace top pressure.

If there is a power outage in the power system, first the circuit breaker 13 is turned off to stop power supply to the main power transmission system 14, and the output of the generator 12 is sent to the safety power transmission system 15.

At the same time, in order to avoid generating excessive power for safety, the on-off valve 4 of the blast furnace blower 2 is closed manually or automatically, and the pressure of the blast furnace gas is lowered.

Then, the shutoff signal a generated when the circuit breaker 13 is turned off and the ventilation stop signal generated when the on-off valve 4 is closed are both sent to the pressure controller 16 that controls the opening degree of the bypass control valve 8. The pressure controller 16 forces the bypass control valve 8 to remain fully closed only when both signals a, l) are input.

Therefore, the furnace top pressure recovery turbine power generation equipment is driven by low-pressure blast furnace gas, and during that time, power for the safety of the blast furnace 1 is supplied.

Normally, the power system is closed during the period when the remaining blast furnace gas can be used.

Note that the ventilation stop signal may also be generated when the electric motor 3 is stopped.

Further, the on-off valve 4 may be closed by the cutoff signal a, and the bypass control valve 8 may be fully closed or maintained fully closed via the pressure controller 16.

As described above, according to the present invention, when there is a power outage in the power system and the power supply to the power transmission system from the furnace top pressure recovery turbine power generation equipment is stopped,
Since the blowing of air from the blast furnace blower to the blast furnace is stopped and electric power commensurate with the safety power is obtained from the power generating equipment, there is an advantage that dangers that may occur due to excessive security power can be avoided.

[Brief explanation of the drawing]

The drawing is a control system diagram showing an embodiment of the present invention. 1...Blast furnace, 2...Blast furnace blower, 4.
...Opening/closing valve, 8...Bypass control valve, 1
0... Turbine, 12... Generator, 1
3... Circuit breaker, 16... Pressure controller,
a... Cutoff signal, b... Ventilation stop signal.

Claims (1)

[Claims] 1. When the electric power system goes out and the power supply to the power transmission system of the furnace top pressure recovery turbine power generation equipment installed in the blast furnace is cut off, the blast furnace blower stops blowing air to the blast furnace, lowers the set pressure of the blast furnace, and starts the turbine. A furnace top pressure system characterized in that a pressure control valve provided in a bypass passage is forced to be fully closed, and low-pressure blast furnace gas drives the furnace top pressure recovery turbine power generation equipment to supply electric power for blast furnace safety. Control method for recovery turbine power generation equipment.