JPH0740820Y2 - Gas turbine fuel supply system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a device for supplying fuel to a combustor of a gas turbine engine used in an automobile or the like.

[Conventional technology]

FIG. 4 shows an outline of the entire structure of an example of a gas turbine engine. In the figure, the air sucked from an air inlet 1 is compressed by a compressor 2, heated by exhaust gas in a heat exchanger 3 and then enters a combustor 4, and is mixed with fuel spray injected from a fuel nozzle 5 and burned. . The high-temperature and high-pressure combustion gas first drives the compressor turbine 6 to give power to the compressor 2, and then drives the power turbine 7 to produce power. Exhaust gas is exhausted from the exhaust outlet 8 after the exhaust heat is supplied to the air in the heat exchanger 3 as described above. The power generated in the power turbine 7 is decelerated by the reduction mechanism 9 and taken out to the output shaft 10.

As a fuel nozzle for such a gas turbine engine,
For example, as described in JP-A-62-70628, it is known to use a double type nozzle, and a typical structure thereof is shown in FIG.

The conventional dual fuel nozzle 11 includes a mounting case 13 mounted on the wall 12 of the combustor 4, an inner case 14 inserted therein,
The outer nozzle tip 15 on the lower side thereof, the inner nozzle tip 16, the branch tip 17, and the distribution valve case 1 in that order on the outer nozzle tip 15.
8. Check valve cases 19 are stacked and fastened with a union nut 20. A valve 22 biased downward by a spring 21 in the distribution valve case 18 is inserted so as to shut off the fuel flow path to the outer nozzle tip 15 at a constant fuel pressure P ₁ or less, while , No valve is provided in the fuel flow path below the distribution valve case 18 to the inner nozzle tip 16 and is normally open, but a spring 23 is provided in the common flow path of the fuel passages. A check valve 24 biased upward by a filter 26 and a filter 26 housed in a filter case 25 are inserted, and pressurized liquid fuel is supplied through a fuel nozzle adapter 27 screwed to the upper end. It is like this.

Combustion, from the air hole 29 provided in the wall of the combustor inner cylinder 28,
High-temperature compressed air compressed by the compressor 2 and heated by the heat exchanger 3 is supplied to the fuel nozzle in the combustor inner cylinder 28.
By mixing with the fuel spray 30 injected while swirling from 11, and ignited by an ignition device (not shown),
It occurs continuously in the combustion zone 31. At this time, the liquid fuel is pressurized by a fuel pump (not shown) and is supplied from the nozzle adapter 27 into the fuel nozzle 11 through the fuel hose. Then, after passing through the filter 26, the check valve 24 is pushed open to flow down, and is injected into the combustor inner cylinder 28 from the normally open inner nozzle tip 16. When the gas turbine engine is not required to have high output, the fuel is swirled and injected from only the injection holes of the inner nozzle tip 16 in this manner. When the pressure exceeds a certain value P ₁ , the valve 22 opens and fuel is also supplied to the outer nozzle tip 15, and swirling fuel injection is also performed from its injection hole to burn. The amount increases.

FIG. 6 shows the flow characteristics of the fuel nozzle 11, where P is the pressure of the liquid fuel, Q is the flow rate (that is, the injection amount or the combustion amount), and the pressure is P ₁ or less during low load operation. In the (first stage), the flow rate is Q ₁ or less, and at this time, fuel is injected only from the injection holes of the inner nozzle tip 16, but in the high-load operation where the pressure exceeds P ₁ (second stage), the flow rate is Q _{When the number is 1} or more, the fuel injected from the injection hole of the outer nozzle tip 15 also joins the spray 30 and burns.

[Problems to be solved by the invention] As described above, the outer nozzle tip 15 to which fuel is supplied only during high load operation and the fuel passage leading to the outer nozzle tip 15 have a small amount of fuel even after the valve 22 is closed during low load operation. Radiant heat from the combustion zone 31 and heat transfer from the combustor wall,
Since it is carbonized by receiving heat of air and the like and blocks the injection hole and the flow path, it becomes impossible to increase the amount of fuel for high-power operation. For example, in the case of a gas turbine used as an engine of a bus or an automobile, the temperature of the air flowing around the fuel nozzle is 500 to 700 ° C because the heat of the exhaust is absorbed by the heat exchanger 3. If the temperature is high and the fuel does not flow and is stagnant, the fuel is carbonized by itself, so that a special measure is required.

[Means for Solving the Problems]

The fuel supply system for a gas turbine of the present invention has a first fuel passage communicating with a first nozzle for constantly injecting fuel during operation and a second fuel passage communicating with a second nozzle for injecting fuel during high load operation. Fuel nozzle, fuel tank provided independently,
A fuel supply line including a fuel pump, a fuel actuator, and a pressure sensor for supplying fuel to the first fuel passage, and a fuel diverted from the fuel supply line during the high load operation to supply fuel to the second fuel passage. However, a valve device provided at the inlet of the second fuel passage so that compressed air can be supplied instead of fuel during low load operation, and includes a metering valve, an air tank and a compressor, and is connected to the valve device. And a control device for controlling the fuel actuator and the valve device according to a load state.

[Action]

Since the present invention has the structure as described above, the fuel in the fuel supply line supplies fuel to the first fuel passage of the fuel nozzle at any time during the operation of the gas turbine engine, and the first fuel passage to the first fuel passage is connected to the first fuel passage. The injection port of is always injecting fuel during that time. In the high load operation state, the control device causes the valve device to supply the fuel in the fuel supply line to the second fuel passage of the fuel nozzle, so that the fuel is also injected from the second injection port and the injection from the first injection port. Burns with fuel. The injection amount of fuel is adjusted by the control device controlling the fuel actuator and changing the fuel pressure of the fuel supply line according to the magnitude of the load.

In the low load operation state, the control device operates the valve device to cut off the fuel supply to the second fuel passage of the fuel nozzle and connect the air supply line instead, so that the second fuel passage and the second injection port are connected. Any remaining fuel will be expelled by the air, the second nozzle will inject air instead of fuel, and the fuel nozzle will be cleaned and cooled. Therefore, the fuel nozzle is prevented from being clogged by the residual fuel being carbonized.

〔Example〕

FIG. 1 shows a first embodiment of the present invention, in which 40 is a fuel tank, 41 is a fuel pump (driven by an engine or a separately provided motor), 42 is a fuel actuator, 43 is a pressure sensor, 44, Reference numerals 45, 46 and 47 are fuel pipes that connect them in sequence to form a fuel supply line, and the last pipe 47 is connected to a first fuel passage 49 of a conceptually shown fuel nozzle 48.

An electromagnetic valve 51 is connected to the fuel pipe 47 through a branched fuel pipe 50, and the end of the solenoid valve 51 is connected to a second fuel passage 52 of the fuel nozzle 48 through pipes 53 and 54. The second fuel passage 52 is further connected to a solenoid valve 55 through a pipe 53, and the tip of the second fuel passage 52 is sequentially connected to a metering valve 56, a vehicle air tank 57, and a compressor driven by an engine.
An air supply line is connected with 58. 59,60,61
Is an air pipe for connection. The vehicle air tank uses only a small amount of air for the device of the present invention, so it may be used for other purposes, such as air suspension and air brake, in the vehicle without using a dedicated one. If there is room (usually they have enough room), then some of that compressed air can be diverted. Further, the metering valve 56 is for limiting the flow rate of air, and even if it is a fixed throttle, there is no practical problem.

A control device including a microprocessor or the like for inputting detection signals of the fuel actuator 42 and the pressure sensor 43 and outputting control signals to the fuel actuator 42, the solenoid valves 51, 55 and the like.
62 is provided to control the operation of a series of devices.

An enlarged view showing the detailed structure of the fuel nozzle 48 and its peripheral portion A is shown in FIG. Reference numeral 64 is the main body of the nozzle, 65 is the outer nozzle tip, 66 is the inner nozzle tip, 67 is an insert that forms the two fuel passages 49 and 52, and 68 and 69 are attached to the fuel passages 49 and 52, respectively. The adapter for connection is shown.

In the embodiment shown in FIGS. 1 and 2, the fuel tank
The fuel of 40 is pressurized by the pump 41, and the fuel actuator 42
Is adjusted according to the control signal of the control device 62, and the pressure sensor
It is sent to the first fuel passage 49 of the fuel nozzle 48 via 43,
The fuel is sprayed while being swirled from the nozzle (first nozzle) of the inner nozzle tip 66 to form the fuel spray 30 in the combustor inner cylinder 28,
It is mixed with the pressurized air sent from the air holes 29 and continuously burned.

When the gas turbine engine is operating under low load, the control device
Although the solenoid valve 51 is closed by the control signal of 62 and the fuel is not supplied to the second fuel passage 52, instead, the solenoid valve 55 is opened by the control signal of the control device 62 and the compressed air in the air tank 57 is released. Second fuel passage 52 through pipes 60, 59, 53 and 54
The fuel remaining in the passage and the nozzle (second nozzle) of the outer nozzle tip 65 is blown away and the tip of the fuel nozzle 48 is cooled.

In this case, the amount of air consumed is a small amount measured by the metering bubble (or fixed throttle) 56 and is within the margin of the air tank 57. If it is not necessary to cool the tip of the fuel nozzle 48, the opening time of the solenoid valve 55 is set to only a short time after the solenoid valve 51 is closed.
It is also possible to use compressed air only by using air only for cleaning residual fuel.

In this way, even when the second injection port is not used, no fuel remains in the injection port, the nozzle tip 65 connected to the injection port, and the fuel passage 52 in the fuel nozzle. There is no risk of clogging.

When the gas turbine engine is under high load operation,
Since the fuel actuator 42 allows a large amount of fuel to pass by the signal of the control device 62, the fuel pressure detected by the pressure sensor 43 exceeds the point corresponding to P ₁ in the explanation of FIG. 6 described above. At this time, the controller 62 simultaneously causes the solenoid valve 55 to
Is closed to stop the air from entering the fuel nozzle 48, and the solenoid valve 51 is opened to partly divide the fuel in the fuel pipe 47 to flow into the second fuel passage 52 of the fuel nozzle 48. Therefore, the fuel is also swirled and injected from the second injection port formed in the outer nozzle tip 65, and the amount of combustion is increased as in the second stage of FIG. The value of P ₁ is about 10 to 30 kg / cm ₂ · G for automobile gas turbine engines.

FIG. 3 shows another embodiment, and in this case also, the fuel nozzle 48 as shown in FIG. 2 can be used. This embodiment differs from the embodiment shown in FIG. 1 in that two solenoid valves 51 are provided.
And 55 are collectively replaced by one electric rotary valve 70. Rotary valve 70 is a control device
The control signal 62 switches the pipe 54 connected to the second nozzle of the fuel nozzle 48 to either the fuel pipe 50 or the air pipe 59. In some cases, the air pipe 59 may be connected to the air pipe 59 for a short period of time and then returned to a neutral position where it does not communicate with either side. Although the structure of this embodiment is partly different, the operation thereof is first.
Since it is obvious from the operation of the illustrated embodiment, detailed description will be omitted.

[Effect of device]

The present invention can exert various excellent effects as described below due to the above configuration.

(1) Since the fuel nozzle is not likely to be clogged with carbon, the reliability and durability of the gas turbine engine and the vehicle are improved, the maintenance period of engine parts is extended, and stable high engine performance can be maintained for a long period of time.

(2) As a secondary trouble, when the second nozzle of the fuel nozzle is closed, the high-pressure fuel is all injected from the first nozzle, and the shape of the spray is biased and a part of the combustor inner cylinder If the carbon is melted or the clogged carbon is blown off, the latter part may be damaged, but such trouble can be prevented.

(3) By flowing compressed air through the second fuel passage and the second nozzle of the fuel nozzle, the fuel nozzle exposed to high temperature can be cooled and protected, and the distortion of the precise mating surface in the nozzle can be prevented. As a result, fuel leakage is prevented.

(4) The structure of the fuel nozzle is simplified, and in particular, since it does not have a switching valve or the like built-in, troubles that are likely to occur in complicated structural parts are avoided, and it is also advantageous in terms of cost.

(5) Since the fuel passage has two independent systems, even if foreign matter is clogged in the fuel passage, both of the two nozzles will not be disabled, and it is possible to perform emergency operation with only one nozzle. Becomes

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing the first embodiment, FIG. 2 is a sectional view showing details of a fuel nozzle portion, FIG. 3 is a system configuration diagram showing the second embodiment, and FIG. FIG. 5 is a perspective view showing the overall configuration of a gas turbine engine, FIG. 5 is a cross-sectional view showing an example of a conventional fuel nozzle, and FIG. 4 ... Combustor, 5 ... Fuel nozzle, 6, 7 ... Turbine, 1
1 …… Fuel nozzle (conventional), 15,65 …… Outer nozzle tip, 16,66 …… Inner nozzle tip, 22 …… Valve, 24…
… Check valve, 30 …… Fuel spray, 40 …… Fuel tank, 41 …… Fuel pump, 42 …… Fuel actuator, 43
...... Pressure sensor, 48 …… Fuel nozzle (invention), 49 ……
First fuel passage, 51, 55 ... Solenoid valve, 52 ... Second fuel passage, 56 ... Metering valve, 57 ... Vehicle air tank, 58 ... Compressor, 62 ... Control device, 70 ... Rotary valve.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F23D 11/38 L

Claims (1)

[Scope of utility model registration request] 1. A fuel in which a first fuel passage communicating with a first nozzle for constantly injecting fuel during operation and a second fuel passage communicating with a second nozzle for injecting fuel during high load operation are independently provided. A fuel supply line that includes a nozzle, a fuel tank, a fuel pump, a fuel actuator, and a pressure sensor to supply fuel to the first fuel passage, and the fuel is diverted from the fuel supply line during the high load operation to the second fuel supply line. Although the fuel is supplied to the fuel passage, a valve device provided at the inlet of the second fuel passage, a metering valve, an air tank and a compressor are provided so that compressed air can be supplied instead of the fuel during low load operation. And an air supply line connected to the valve device, and a control device for controlling the fuel actuator and the valve device according to a load state. The fuel supply apparatus for a gas turbine engine.