JPH0968054A - Fuel controller and fuel supply method for gas turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable hammering to be prevented from its occurrence in a low boiling point fuel system piping when a low boiling point fuel shut-off valve is opened, in a dual fuel combustion gas turbine using both low boiling point fuel and high boiling point fuel. SOLUTION: A fuel controller for a dual fuel combustion gas turbine using low boilling point fuel and high boiling point fuel by mixing them together or switching them from each other is provided with a bypass line 15 for bypassing the shut-off valve 4a in a low boiling point fuel system. And a shut-off valve bypass valve 17 and an orifice 16 are provided side by side in the bypass 15. A low boiling point fuel is supplied to this fuel controller, the shut-off valve 4A is opened after setting the shut-off valve bypass valve 17 is in its opening position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel control system for a dual fuel combustion gas turbine which uses a low boiling point fuel such as liquefied butane and a high boiling point fuel such as A heavy oil.

[0002]

2. Description of the Related Art FIG. 2 is a fuel control system diagram of a conventional dual fuel combustion gas turbine using a low boiling point fuel and a high boiling point fuel. Low boiling point fuels such as liquefied butane and liquefied propane are supplied to the receiver tank 1, the fuel pump 2, the pressure control valve 3,
It flows into the mixer 7 through the shutoff valve 4 a, the throttle valve 5, and the check valve 6. The pressure control valve 3 regulates the pressure of the fuel oil according to the signal from the pressure detector 8.

Further, depending on the opening degree of the throttle valve 5 whose opening degree is controlled according to the load, excess fuel branches from the downstream side of the pressure control valve 3 to the return system, and the orifice 9, the cooler 10, It flows back to the receiver tank 1 via the orifice 11.

On the other hand, high boiling point fuel such as kerosene, light oil, heavy oil A, etc., flows into the mixer 7 through the strainer 12, the fuel pump 2, the shutoff valve 4B, the throttle valve 5 and the check valve 6. The pressure control valve 3 is operated by the signal of the pressure detector 8, and the excess fuel flows back to the suction side of the fuel pump through the pressure control valve 3 and the orifice 9.

The dual fuel mixed in the mixer 7 passes through the shutoff valve 13 and is injected from the fuel injection nozzle 14 into the combustor. In this way, in the dual fuel combustion gas turbine, the gas turbine can be operated with both the low boiling point fuel and the high boiling point fuel, and the two types of fuels, the low boiling point fuel and the high boiling point fuel, can be operated at any ratio. Can be burned.

[0006]

In the conventional dual-fuel combustion gas turbine having the above-mentioned structure, when the low boiling point fuel cutoff valve 4A is opened during the supply of the low boiling point fuel, the piping on the downstream side of the low boiling point fuel cutoff valve 4A is provided. Since the system is in the gas phase, the fuel is flushed downstream of the pressure control valve 3 at the same time when the shutoff valve 4A is "opened". Then, the fuel is repeatedly condensed and liquefied.

The flushing of the low boiling point fuel and the increase and decrease in volume due to condensation and liquefaction may cause hammering in the piping system, and the vibration may damage the piping system.

According to the present invention, in a dual fuel combustion gas turbine using a low boiling point fuel and a high boiling point fuel, it is possible to prevent hammering from occurring in the low boiling point fuel system pipe when the low boiling point fuel cutoff valve is opened. It is an object of the present invention to provide a fuel control device and a fuel supply method thereof.

[0009]

In order to solve the above problems in a dual fuel combustion gas turbine in which a low boiling point fuel and a high boiling point fuel are co-firing or switched, the present invention bypasses a low boiling point fuel system shut-off valve. A bypass line is provided, and a cutoff valve bypass valve and an orifice are connected to the bypass line.

Since the fuel control system for a dual fuel combustion gas turbine according to the present invention has the above-mentioned structure, by opening the shut-off valve bypass valve before opening the shut-off valve of the low boiling point fuel system, the shut-off valve and the following valves are opened. Since the downstream side of the shutoff valve is preloaded by the fuel whose flow rate is restricted by the orifice, hammering does not occur even when the shutoff valve is opened. When the shutoff valve is opened, the shutoff valve bypass valve is automatically closed.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A fuel control system for a dual fuel combustion gas turbine and a fuel supply method therefor according to the present invention will be specifically described below based on the embodiment shown in FIG. In the following embodiments, the same components as those of the conventional apparatus shown in FIG. 2 are denoted by the same reference numerals for simplification of description.

In the fuel control system of the dual fuel combustion gas turbine shown in FIG. 1, unlike the conventional system shown in FIG. 2, the bypass line 1 is provided in the shutoff valve 4A of the low boiling point fuel system.
5, a bypass line 15 is provided with an orifice 16 and a shutoff valve bypass valve 17. In addition,
Generally, the nominal diameter of the shutoff valve bypass valve 17 is smaller than the nominal diameter of the shutoff valve 4A.

The fuel control system for a dual fuel combustion gas turbine shown in FIG. 1 has a bypass line 15 of the above construction.
Therefore, if the shut-off valve bypass valve 17 is opened before the shut-off valve 4A of the low boiling point fuel system is opened, the flow rate of the shut-off valve 4A and thereafter is restricted by the orifice 16 and the downstream side of the shut-off valve is pre-pressurized. It Therefore, even if the shutoff valve 4A is opened, hammering does not occur in the low boiling point fuel system. The shutoff valve bypass valve 17 is automatically closed when the shutoff valve 4A is opened.

[0014]

As described above, in the fuel control system for the dual fuel combustion gas turbine according to the present invention,
Since a bypass line for bypassing the low boiling point fuel system shutoff valve is provided, and the shutoff valve bypass valve and the orifice are connected in series to the bypass line, according to this configuration, when supplying the low boiling point fuel system, By opening the cutoff valve bypass valve and then opening the cutoff valve, hammering of the low boiling point fuel system piping is prevented, and the reliability of the gas turbine fuel control device is improved.

[Brief description of drawings]

FIG. 1 is a fuel supply system diagram of a dual fuel combustion gas turbine including a gas turbine fuel control device according to an embodiment of the present invention.

FIG. 2 is a fuel supply system diagram of a conventional dual fuel combustion gas turbine.

[Explanation of symbols]

 1 Receiver Tank 2 Fuel Pump 3 Pressure Control Valve 4A Low Boiling Fuel System Shutoff Valve 4B High Boiling Fuel System Shutoff Valve 5 Throttle Valve 6 Check Valve 7 Mixer 8 Pressure Detector 9 Orifice 10 Cooler 11 Orifice 12 Strainer 13 Shutoff valve 14 Fuel injection nozzle 15 Bypass line 16 Orifice 17 Shutoff valve Bypass valve

Claims (2)

[Claims] 1. A dual-fuel combustion gas turbine that uses a low-boiling point fuel and a high-boiling point fuel by co-firing or switching, and a bypass line that bypasses a low-boiling point fuel system shut-off valve is provided, and a shut-off valve bypass valve is provided in the bypass line. A fuel control device for a dual-fuel combustion gas turbine, characterized in that orifices are connected in series. 2. The fuel control device according to claim 1, wherein when the low boiling point fuel is supplied, the shutoff valve bypass valve is opened and then the shutoff valve is opened.