JPS5928023A - Residual liquid fuel purifying method of gas turbine and device thereof - Google Patents

Abstract

PURPOSE:To perform discharge of residual liquid fuel in a duct reliably, by a method wherein part of gaseous fuel is spouted into a combustor from a nozzle through a liquid fuel duct at the time of changeover from liquid fuel burning to gaseous fuel burning, in a two-fuel burning gas turbine. CONSTITUTION:When liquid fuel burning is changed over to gaseous fuel burning while a gas turbine is being operated by spouting liquid fuel to be discharged from a fuel pump 14 into a combustor 1 from a nozzle 2 through a check valve 13, a main stop valve 12 and a fuel control valve 11, the fuel pump 14 is suspended, to begin with. Then, hydraulic pressure at a port (c) of a valve device 24 is lowered, a valve 27 is opened by a spring 30 and part of gaseous fuel in gaseous fuel piping 3 flows in liquid fuel piping 5 through piping 23. Although the gaseous fuel is spouted into the combustor 1 from the nozzle 2 through the control valve 11, at this time residual liquid fuel in a liquid fuel duct provided with the piping 5, control valve 11 and the nozzle 2 is spouted into the combustor 1 and the inside of the duct is purified.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] Unexploded +111 is a dual-fuel-fired gas turbine ≦2. The device (related to

[Technical background of the invention and its problems]

There are dual-fuel gas turbines configured to fire liquid fuel and gas fuel simultaneously or alternately. The fuel system and the gaseous fuel system are connected to the liquid fuel injection port and the gaseous fuel injection port of the nozzle of the combustor, respectively. The residual liquid fuel in the resulting flow path is ashed by the heat received from the combustor, and θ1
f. There is a risk of blocking the tract. Therefore, when switching fuels (2) in the flow path; 2) remaining fuel must be reliably cleaned.

Therefore, the fuel control valve and fuel stop valve used in this fuel system (Secondly, to ensure the minimum fuel flow rate at the time of ignition, and to clean the residual fuel at the time of stoppage) is being done.

In other words, in the case of a fuel control valve (2 is fully closed), the structure is such that a stopper is inserted to prevent it from becoming mechanically maintained at the minimum opening (2), and in the case of a ball stop valve, the valve is in the fully open position. The structure is such that the control valve's minimum opening and the drain boat of the main stop valve are used to drain the remaining liquid fuel from the drain tank to the drain tank using the internal pressure of the combustor. It looks like it's being swept away.

However, in the fuel system of a conventional dual-fuel gas turbine, when switching from liquid fuel to gaseous fuel (2), the pump that pumps the liquid fuel is either stopped or the stop valve is left open ( As a result, residual fuel remains in the liquid fuel flow path, and the pIP4 that this residual liquid fuel receives from the combustor eliminates the volatile components in the fuel, causing it to carbonize and easily cause nozzle clogging9. .

[Purpose of the invention]

The purpose of the present invention is to automatically clean residual liquid fuel in the two passages to prevent clogging of nozzles and passages when switching from liquid fuel firing to gaseous fuel firing (residual liquid fuel in the second gas turbine). Dispersed fuel cleaning method and apparatus are provided (there are two types).

[Summary of the invention]

The present invention is characterized in that when switching from liquid fuel burning to gaseous fuel burning, the gaseous fuel is introduced into the liquid fuel flow path (2) and the residual liquid fuel in the flow path is purged. Method for cleaning residual liquid fuel in a gas turbine (1).

The present invention comprises a combustor (two devices) having a nozzle having a liquid fuel injection port and a gaseous fuel injection port, and connects each liquid fuel injection port and gaseous fuel injection port (=liquid fuel piping and gaseous fuel piping, respectively). , between the two fuel pipes (when the power is switched from two-liquid fuel firing to gaseous fuel firing), the pipe is equipped with a valve device for introducing the gaseous fuel into the liquid fuel piping. This invention relates to a residual liquid fuel cleaning device for a gas turbine.

[Embodiments of the invention]

Embodiments of the invention illustrated in the drawings will be described below. First, in FIG.
A gas turbine is a heat engine that uses gas as the working fluid and generates mechanical power through the process of compressing air with a compressor and heating it to produce high-pressure, high-temperature gas that expands in the turbine. There is a dual-fuel burning gas turbine that generates power in a working fluid (two fuels) and can burn liquid fuel and gaseous fuel simultaneously or alternately.

The inlet of a dual-fuel-fired gas turbine is provided with a combustor 1 (the second is a nozzle 2 having a liquid fuel injection port 2b and a gaseous fuel injection port 2a). Gaseous fuel is supplied from a gaseous fuel source 4 through a gaseous fuel pipe 3 and a liquid fuel injection port 2bl.
Second, liquid fuel is supplied from a liquid fuel tank 6 through a liquid fuel pipe 5.

In the middle of the gaseous fuel pipe 3 (2), there are provided a fuel control valve 8 whose opening and closing are controlled by the working oil pressure 7a and a fuel stop valve 9 whose opening and closing are also controlled by the working oil pressure 7b.

The liquid fuel pipe 5 sea connects a fuel control valve 11 with an orifice 10 that is controlled to open and close by a working oil pressure 7c, and a fuel stop valve 12 that is also controlled to open and close by a working oil pressure 7d, and further includes a (binary stop valve 13). and a fuel pump 14. Also, a fuel stopper valve 12 (inside the drain tank 15) is connected.
A drain pipe 16 is provided leading to the drain tank 15 so that when the earth stopper valve 12 is closed, the fuel on the downstream side flows into the drain tank 15 (secondary flow).A leak pipe 17 is also provided in the fuel control valve 11 to prevent this. It communicates with the drain pipe 16. The drain tank 15
The fuel in the fuel tank 6 (secondary) is transferred to the piping 20 via the drain tank 18 and the check valve 19.

Now, between the downstream side of the gaseous fuel pipe 30 stop valve 8 and the downstream side of the fuel stop valve 12 of the liquid fuel pipe 5, a pipe W23 is provided via check valves 21 and 22 in the direction shown in the figure, respectively. In the middle of this piping system (= when switching from liquid fuel firing to gaseous fuel firing) (24 is provided in the valve equipment that connects the gaseous fuel in the two gaseous fuel piping 3 to the liquid fuel piping 5 (-). As shown in Fig. 2, the device is equipped with a valve seat base in the passages a and b at the lower end of the E oil cylinder 5 (bows connecting the two pipes), and this valve seat 2
64 Two valves n face each other, the valve stem of this valve n is connected to a piston (2) that slides on an oil cylinder δ, and this piston 4 is connected to a spring (9).
), the valve n is always deviated from the valve seat 26 in the opening direction. Therefore, in the state shown in FIG. 2, the valve z7 is in the open position 4 (2, bow) bl- with the spring 301 (therefore, the working fluid entering the valve z7 exits from the boat a). However, when working fluid enters from boat c, piston 4 is pushed down against the spring force, causing the valve seat to come into close contact with valve n, cutting off the passage from boat b to boat aζ2. When the working fluid is removed, the valve υ is pulled up by the spring force and opens a passage from the boat c to the boat a). The boat A is connected to the pipe n on the check valve n side, and the boat C is connected to the liquid fuel pipe 5 on the downstream side of the fuel pump 14 (two connections are made).

Next (2) A method for cleaning residual liquid fuel in a gas turbine according to the present invention will be explained in two parts. In the case of liquid fuel firing, the discharge pressure of the fuel pump 14 is high pressure, the check valve 13, the main stop valve 12 and The fuel is injected into the combustor 1 from the nozzle 2 through the fuel control valve 11.At this time, the high-pressure fuel from the fuel pump 14 enters from the boat c and presses down the piston 4, causing the valve 27 to press down on the valve seat. Since 26 is closed, the piping will be cut off to that passage.

If you switch from liquid fuel firing to gaseous fuel firing now, the fuel pump 14 will stop and the oil pressure of the boat C in the valve device t24 will drop, so the valve 27 will not open the valve seat directly due to the spring 30 (2). .This valve 27 is fully opened (so that some of the gaseous fuel pipe 3 passes through the check valve 21 or the blind valve).
The liquid flows from bow) b of the valve device U to bow) a, passes through the check valve 4, and enters the liquid twist*+ pipe 5. Then, the gaseous fuel passes through the control valve 11 and is injected from the nozzle 2 into the combustor 1 (=injected. = Therefore, liquid fuel is injected into the combustor 1, and the inside of the flow path is cleaned. Therefore, clogging of the nozzle 2 is prevented, and a highly reliable fuel system is obtained.Also, liquid fuel is injected into the flow path. Since the gaseous fuel pressure is diverted from the downstream side of the fuel control valve 8, the pressure is regulated by this valve 8.

Another embodiment shown in FIG.
The boat d of the valve device u is connected to the drain pipe 16 by a drain pipe 31. In this embodiment, the liquid fuel control valve 1
It is possible to clean the residual fuel inside the control valve 11, and the pipe can be used as a part of the leak pipe 17 of the control valve 11 when burning liquid fuel.

〔Effect of the invention〕

That's all! -2 In the present invention, when switching from liquid fuel firing to gaseous fuel firing (- gaseous fuel is introduced into the liquid fuel flow path (2), the liquid fuel flow path ζ2 remains Liquid fuel can be cleaned, nozzle clogging can be prevented, and a highly reliable gas turbine fuel system can be maintained.

[Brief explanation of the drawing]

Fig. 1 is a fuel system diagram showing an embodiment of the residual liquid fuel cleaning device for a gas turbine according to the present invention (2), Fig. 2 is a sectional view showing a valve device used in the present invention (2), and Fig. It is a fuel system diagram showing another embodiment of the invention. 1... Combustor 2... Nozzle 3... Gaseous fuel piping 4... Gaseous fuel source 5... Liquid fuel front v 6...・Liquid fuel tank 7a+ 7b+ 7
c...Operating oil pressure 8...Fuel control valve 9...Fuel top stop valve 10...Orifice 11...Fuel control valve 12...Fuel top stop valve 14...Fuel pump...・Piping... Valve equipment (8733) Agent: 5th Department Engineer Yoshiaki Inomata (and 1 other person) Figure 1 Figure 2 E

Claims (2)

[Claims] (1) Gas turbine that uses both liquid fuel firing and gaseous fuel firing) Second, when switching from liquid fuel firing to gaseous fuel firing (=, part of the gaseous fuel is passed through the liquid fuel flow path and released from the nozzle. A method for cleaning residual liquid fuel in a gas turbine, characterized by cleaning residual liquid fuel in a flow path by injecting it into a combustor. (2) A nozzle having a liquid fuel injection port and a gaseous fuel injection port is connected to a combustor (two devices, and the liquid fuel injection port and the gaseous fuel injection port (= liquid fuel piping and gaseous fuel piping, respectively) are connected, When switching from liquid fuel firing to gas fuel firing with both fuel piping and piping, residual gas turbine is characterized by having a pipe line with a valve device l that introduces gaseous fuel into the liquid fuel flow path opening. Liquid fuel purification device.