JP2807556B2 - Fuel supply method and gas turbine equipment for oil-fired gas turbine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fuel supply method for an oil-fired gas turbine and gas turbine equipment for performing the method, and particularly relates to a nitrogen oxide (hereinafter “NOx”) method. The present invention relates to a fuel supply method for an oil-fired gas turbine and gas turbine equipment suitable for reducing the amount of generation of the premixed fuel and preventing spontaneous ignition of the premixed fuel in the pre-evaporation pre-mixer.

[Prior Art] As one of the methods for reducing the amount of NOx in the exhaust gas of a gas turbine, as described in JP-B-59-50889, a technique of premixing and evaporating fuel and then burning it. Is well known.

The main components of the combustor in the prior art are a head combustion chamber, a pre-evaporation premixing chamber surrounding the main combustion chamber and the head combustion chamber in an annular shape, and a fuel nozzle. The feature of the prior art is to provide a pre-evaporation pre-mix chamber, evaporate fuel, pre-mix with air, and perform lean pre-mix combustion at the outlet of the pre-evaporation pre-mix chamber.

Lean premixed fuel has a low NOx generation, so-called low N
This is a technique called Ox combustion.

[Problems to be Solved by the Invention] By the way, in the prior art, if the pre-evaporation pre-mixer forming the pre-evaporation pre-mixing chamber is lengthened, the pre-mixing of fuel pre-evaporation and air is completely performed, There is an advantage that the NOx generation amount is very small. However, the residence time of the fuel in the pre-evaporation pre-mixer becomes longer, and the fuel often ignites spontaneously,
There was a disadvantage that the functions of pre-evaporation and pre-mixing were impaired.

Therefore, if the length of the pre-evaporation premixer is reduced to prevent spontaneous ignition of the fuel, the residence time of the fuel is short and spontaneous ignition hardly occurs, but on the contrary, the pre-evaporation and pre-mixing of the fuel are insufficient. Therefore, the NOx generation amount does not decrease as expected.

Therefore, the length of the pre-evaporation pre-mixer has to be determined based on a compromise between the reduction of the NOx generation amount and the prevention of spontaneous ignition, and there is a natural limit in reducing the NOx in the prior art.

That is, in the prior art, due to the problem of spontaneous ignition of fuel, the characteristics of pre-evaporation / premixed combustion cannot be fully utilized.

A first object of the present invention is to provide a fuel supply method for an oil-fired gas turbine that can significantly reduce the amount of NOx generated and can prevent spontaneous ignition of premixed fuel in a pre-evaporation pre-mixer. is there.

Further, a second object of the present invention is to provide a gas turbine facility of an oil-fired gas turbine that can accurately carry out the fuel supply method.

[Means for Solving the Problems] The first object is achieved by preheating a premixed fuel by a heating medium and supplying the preheated premixed fuel to a preevaporation premixer of a combustor. .

The first object is also achieved by heating compressed air sent to a pre-evaporation pre-mixer in a combustor, and mixing the heated compressed air with a pre-mixed fuel.

Further, the first object is also achieved by heating the wall surface of the pre-evaporation pre-mixer and supplying the pre-mixed fuel.

Still further, the first object is to heat a wall surface of the pre-evaporation pre-mixer, and pre-heat the pre-mixed fuel by a heating medium,
It is also achieved by heating the compressed air sent to the pre-evaporation pre-mixer, supplying the pre-heated pre-mixed fuel and the heated compressed air to the pre-evaporation pre-mixer, and mixing.

The second object is that the combustor has a premixed fuel nozzle for ejecting the supplied premixed fuel, introduction means for guiding compressed air discharged from the compressor, and the premixed compressed air and the premixed fuel. This is achieved by having a pre-evaporation pre-mixer that mixes the fuel from the fuel nozzle and guides the fuel into the combustion chamber, and a pre-heating unit that pre-heats the pre-mix fuel supplied to the pre-mix fuel nozzle.

Further, the second object is also achieved when the combustor has a means for heating the compressed air by the introduction means and mixing with the premixed fuel, instead of the preheating means.

Further, the second object is that a combustor is provided instead of the preheating means or the means for mixing with the premixed fuel,
It is also achieved by having heating means for heating the components of the pre-evaporation pre-mixer.

Further, the second object is that a combustor heats preheating means for preheating the premixed fuel supplied to the premixing fuel nozzle, heating means for heating the compressed air, and heating of the components of the preevaporation premixer. This is also achieved by having a heating means that performs heating.

[Operation] In the method of the present invention, the premixed fuel is preheated by the heating medium, and the preheated premixed fuel is supplied to the preevaporation premixer of the combustor.

Thereby, the premixed fuel sprayed into the preevaporation premixer evaporates in a short time, mixes with the compressed air, and burns.
Since the preheated premixed fuel has a high temperature, the surface tension of the fine particles of the premixed fuel is reduced, so that the evaporation is accelerated.

Therefore, lean premix combustion can be reliably realized, and the NOx generation amount can be significantly reduced.

Moreover, since the premixed fuel can be evaporated in a short time, the length of the premixed premixer can be shortened, so that the spontaneous ignition of the premixed fuel in the premixed premixer can be reliably prevented. Becomes possible.

Further, in the method of the present invention, the compressed air sent to the pre-evaporation pre-mixer is heated, and the heated compressed air is mixed with the pre-mixed fuel.

As a result, the evaporation of the premixed fuel is promoted by the heated compressed air, so that lean premixed combustion can be reliably achieved, so that the amount of NOx generated can be significantly reduced, and the length of the preevaporated premixer is reduced. , The spontaneous ignition of the premixed fuel in the pre-evaporation pre-mixer can be reliably prevented.

Further, in the method of the present invention, the wall surface of the pre-evaporation pre-mixer is heated to supply the pre-mixed fuel.

As a result, the pre-mixed fuel is sprayed into the pre-evaporation pre-mixer in the warmed-up state, and the evaporation of the pre-mixed fuel is promoted, so that lean pre-mixed combustion can be reliably realized, and thus the NOx generation amount is significantly reduced. In addition, since the length of the pre-evaporation mixer can be shortened, spontaneous ignition of the pre-mixed fuel in the pre-evaporation pre-mixer can be reliably prevented.

Still further, in the method of the present invention, the wall surface of the pre-evaporation pre-mixer is heated, the pre-mixed fuel is pre-heated by a heating medium, and the compressed air sent to the pre-evaporation pre-mixer is further heated. The preheated premixed fuel and the heated compressed air are supplied and mixed. As a result, since the evaporation of the premixed fuel is further promoted, lean premixed combustion can be realized more accurately, and therefore, the NOx generation amount can be significantly reduced, and the length of the preevaporated premixer can be shortened. Spontaneous ignition of the premixed fuel in the preevaporation premixer can be reliably prevented.

And in the gas turbine equipment of the present invention, the combustor is
A premixed fuel nozzle for ejecting the supplied premixed fuel,
Introducing means for guiding the compressed air discharged from the compressor, a pre-evaporation pre-mixer for mixing the compressed air by the introducing means and the fuel from the pre-mixed fuel nozzle and guiding the mixture to a combustion chamber; Since the apparatus has the preheating means for preheating the supplied premixed fuel, the method of the present invention can be accurately performed.

Further, since the above-mentioned equipment of the present invention has a heating means for heating the compressed air sent to the pre-evaporation pre-mixer, the gas turbine equipment can also accurately carry out the method of the present invention.

Further, since the above-mentioned equipment of the present invention has a heating means for heating the constituent members of the pre-evaporation pre-mixer, the gas turbine equipment can also accurately carry out the method of the present invention.

Still further, in the above facility of the present invention, the combustor includes a preheating means for preheating the premixed fuel supplied to the premixed fuel nozzle, a heating means for heating the compressed air, and a component of the preevaporation premixer. And a heating means for heating the above, so that the method of the present invention can be more accurately performed.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a gas turbine system for carrying out the method of the present invention, in which a combustor is cut in a radial direction, and the relationship between the combustor and various systems connected thereto is shown. FIG.

In the gas turbine equipment of this embodiment, a fuel pump 1 is provided in a fuel system 1. Further, a fuel bypass 3, a diffusion fuel system 4, and a premix fuel system 5 are connected to the fuel system 1 downstream of the fuel pump 2.

The fuel bypass 3 is provided with a bypass valve 6, and the diffusion fuel system 4 is provided with a fuel flow control valve 7.
The premixed fuel system 5 is provided with another fuel flow control valve 8. The bypass valve 6 and the fuel flow control valves 7, 8
It is connected to the fuel controller 9. The diffusion fuel system 4 is connected to a diffusion fuel nozzle 18 of the combustor 10, and the premixed fuel system 5 is connected to a premixed fuel manifold 21 of the combustor 10.

The combustor 10 includes first and second outer cylinders 11 and 12, which are connected on the same center line and constitute a pressure chamber, and a first outer cylinder 1
An end cover 13 attached to one end, a premixed fuel flange 14 having a premixed fuel passage 20 and provided between the first and second outer cylinders 11 and 12; 2nd outer cylinder 1
A combustor sub-chamber 15 installed at the center of each of the first and second combustors 12 and 12;
Combustor main chamber 16 installed on the side and mounting flange 17
A diffusion fuel nozzle 18 attached to the end cover 13 via an air swirler installed at an upstream end thereof.
A premixed fuel manifold 21 which is communicated with a premixed fuel passage 20 provided on the inner peripheral side of the premixed fuel flange 14 and on the outer peripheral side of the combustor sub-chamber 15;
A plurality of premixed fuels are arranged at equal circumferential intervals on the outer peripheral side of the fuel cell 15 and one end is connected to the premixed fuel manifold 21 and the other end is provided toward the combustor main chamber 16. The nozzle 22 is disposed on the outer peripheral side of the end of the combustor sub-chamber 15 and has one end formed to surround the outside of the premixed fuel nozzle 22 and the other end provided facing the combustor main chamber 16. A pre-evaporation pre-mixer 23 is provided, and a compressed air introduction unit 24 having an air passage 25 and connected to an end of the second outer cylinder 12 is provided. The combustor sub-chamber 15 is supported by the first outer cylinder 11 via a support (not shown), and is connected to the combustor main chamber.
16 is supported by the second outer cylinder 12 by another support (not shown), and the pre-evaporation pre-mixer 23 is fixed to the pre-mixed fuel flange 14.

The combustor 10 in this embodiment employs a two-stage combustion system of diffusion combustion and premix combustion.

The premixed fuel system 5 is provided with premixed fuel preheating means 26 on the downstream side of the fuel flow control valve 8. As the preheating means 26, a heat exchanger for preheating the premixed fuel 103 by heat exchange between the premixed fuel 103 and the heating medium 108, or a heater for preheating the premixed fuel 103 with the heating medium 108 is used. Further, the preheating means 26 is provided with a heating medium supply pipe 27 and a heating medium flow control valve 28. Further, the premixed fuel system 5 is provided with a fuel pressure gauge 29 and a fuel thermometer 30 downstream of the preheating means 26. The fuel pressure gauge 29 and the fuel thermometer 30, and the heating medium flow control valve 28 are connected to a heating medium controller 31. The heating medium controller 31 stores a fuel pressure-temperature gas-liquid boundary diagram 32 shown in FIG. 8 in advance. The heating medium controller 31 takes in the measured values of the fuel pressure and the fuel temperature of the premixed fuel 103 from the fuel pressure gauge 29 and the fuel thermometer 30, and uses these measured values in the pressure-temperature gas-liquid boundary diagram 32. And the heating medium flow control valve 28 along the operation line with the safety factor added to the gas-liquid boundary line.
Control signal to the heating medium 108 flowing into the preheating means 26.
It is configured to adjust the flow rate of.

A first electric heater 33 that heats compressed air 105 supplied from the air passage 25 to the pre-evaporation premixer 23 is installed in the air passage 25 provided in the compressed air introduction part 24.

On the inner peripheral surface side of the pre-evaporation pre-mixer 23, a second electric heater 34 for heating the wall surface of the pre-evaporation pre-mixer 23 is provided.

Next, an example of the fuel supply method of the present invention will be described in relation to the operation of the gas turbine equipment of the embodiment shown in FIG.

The fuel 100 supplied through the fuel system 1 is pressurized by the fuel pump 2.

After the start of operation, the fuel 100 may be reduced, and a part 101 of the fuel is returned to a fuel tank (not shown) through the fuel bypass 3 and the bypass valve 6.

In the two-stage combustion system of this embodiment, the premixed fuel 10
3 is supplied to the pre-evaporation pre-mixer 23 of the combustor 10 for the first time after the gas turbine (omitted in FIG. 1) takes a load.

As mentioned above, after the gas turbine takes the load,
The fuel 100 is branched to the diffusion fuel system 4 and the premixed fuel system 5 through the fuel flow control valves 7 and 8.

The opening and closing of the bypass valve 6 and the fuel flow control valves 7, 8 and the adjustment of the opening are performed by a fuel controller 9.

The diffusion fuel 102 branched to the diffusion fuel system 4 is supplied to the diffusion fuel nozzle 18 and is sprayed from the diffusion fuel nozzle 18 into the combustor sub-chamber 15 by pressure spray or air spray. However, the atomizing air system is not shown. Further, the diffusion fuel 102 sprayed with pressure or air into the combustor sub-chamber 15
Is diffused and combusted with the surrounding air 104 flowing from an air hole (not shown) of the combustor sub-chamber 15. This diffusion combustion flame is indicated by reference numeral 106 in FIG.

On the other hand, when the oil-fired gas turbine is started, the heating medium 108 is supplied to the preheating means 26 provided in the premixed fuel system 5 through the heating medium supply pipe 27 so that the premixed fuel 103 can be preheated by the heating medium 108. It has become.

After the start of the oil-fired gas turbine, a first electric heater 33 provided in the air passage 25 of the compressed air introduction section 24 and a second electric heater provided on the inner peripheral side of the pre-evaporation premixer 23 34
And fire. Then, the compressed air 105 flowing into the pre-evaporation pre-mixer 23 through the air passage 25 is heated by the first electric heater 33. Further, the wall surface of the pre-evaporation pre-mixer 23 is warmed up by the second electric heater 34 so that the droplets of the pre-mixed fuel 103 supplied to the pre-evaporation pre-mixer 23 are easily evaporated.

Therefore, the premixed fuel 103 branched from the fuel system 1 to the premixed fuel system 5 passes through the preheating means 26, during which heat exchange is performed with the heating medium 108 supplied to the preheating means 26 through the heating medium supply pipe 27. Alternatively, it is heated by the heating medium 108 and is preheated to a state where it is easily evaporated. Preheating means 26
The premixed fuel 103 preheated through the premixed fuel system 5 again flows into the premixed fuel manifold 21 via the premixed fuel passage 20 provided in the premixed fuel flange 14.

Downstream of the preheating means 26, the pressure and temperature of the preheated premixed fuel 103 are measured by a fuel pressure gauge 29 and a fuel thermometer 30, and the measured values are sent to a heating medium controller 31. Meanwhile, the heating medium controller
The pressure-temperature gas-liquid boundary diagram 32 shown in FIG. Therefore, the heating medium controller 31 takes in the respective measured values from the fuel pressure gauge 29 and the fuel thermometer 30 and compares them with the pressure-temperature gas-liquid boundary diagram 32,
Pressure-Temperature Gas-Liquid Boundary Line A control signal is supplied to the heating medium flow control valve 28 to adjust the pressure and temperature of the premixed fuel 103 along an operation line obtained by adding a safety factor to the gas-liquid boundary line in FIG. To adjust the flow rate of the heating medium 108 appropriately.

The premixed fuel 103 preheated by the preheating means 26 and flowing into the premixed fuel manifold 21 is distributed from the premixed fuel manifold 21 to a plurality of premixed fuel nozzles 22, and the premixed fuel nozzles 22 Evaporation premixer 23 is sprayed with pressure or air. However, the atomizing air system is not shown.

Premixed fuel 10 sprayed from the premixed fuel nozzle 22
3 is premixed in the pre-evaporation premixer 23 with the compressed air 105 flowing from the surroundings.

The compressed air 105 flowing into the pre-evaporation pre-mixer 23
Is heated by a first electric heater 33 installed in the air passage 25 of the compressed air introduction part 24, and has a higher temperature than the temperature when it is discharged from an air compressor (omitted in FIG. 1). . Further, the wall surface of the pre-evaporation pre-mixer 23 is heated by a second electric heater 34 provided on the inner peripheral surface side of the pre-evaporation pre-mixer 23, and is warmed up so that the droplets of the pre-mixed fuel nozzle 22 can be easily evaporated. It has become.

As described above, the premixed fuel 103 is preheated by the preheating means 26, atomized from the premixed fuel nozzle 22 by pressure spraying or air spraying, and introduced into the preevaporation premixer 23. At this time, the pressure in the pre-evaporation pre-mixer 23 is
As low as 10 to 13 atg, the premixed fuel 103 quickly moves from the liquid state C to the gaseous state D in FIG. 8 and evaporates in a short time.

The compressed air 105 flowing into the pre-evaporation pre-mixer 23
Is heated by the first electric heater 33, and the wall surface of the pre-evaporation pre-mixer 23 is further heated by the second electric heater 34, so that the surrounding atmosphere where the pre-mixed fuel 103 is sprayed has a high temperature. Therefore, the surface tension of the fine particles of the sprayed premixed fuel 103 decreases, so that the evaporation of the premixed fuel 103 is further promoted.

Therefore, even if the length of the pre-evaporation pre-mixer 23 is shortened, the evaporation rate of the pre-mixed fuel 103 can be made close to 100%,
Since lean premixed combustion can be reliably realized, the amount of NOx generated can be extremely reduced.

Further, since the length of the pre-evaporation pre-mixer 23 can be reduced, the spontaneous ignition of the pre-mixed fuel 103 can be almost eliminated.

The premixed fuel 103, which is pressure-sprayed or air-sprayed to the pre-evaporation pre-mixer 23 and evaporated, and pre-mixed with the compressed air 105 flowing into the pre-evaporation pre-mixer 23, emits the diffusion combustion flame 106 as a heat source. Premixed combustion is performed in the combustor main chamber 16 with the aid of the high-temperature gas generated as the auxiliary gas. The premixed combustion flame is indicated by reference numeral 107 in FIG.

The high-temperature and high-pressure combustion gas generated by the premix combustion in the combustor main chamber 16 is supplied to a gas turbine, and thermal energy of the combustion gas is converted into mechanical energy.
The gas turbine is driven to rotate.

In the embodiment shown in FIG.
Instead of the electric heaters 33 and 34, other heating means may be used.

Further, when the premixed fuel system 5 between the preheating means 26 and the premixed fuel flange 14 is provided with a heat retaining means to keep the premixed fuel 103 warm, the thermal efficiency for evaporating the premixed fuel 103 can be improved.

Further, by providing the preheating means 26 as close as possible to the premixed fuel flange 14, the heat retaining means applied to the premixed fuel system 5 can be shortened.
The heat radiation of 103 can be reduced.

Next, FIG. 2 is a system diagram showing a specific embodiment of a preheating means for premixed fuel.

In the embodiment shown in FIG. 2, an air compressor 36 and a generator 37 are connected to a gas turbine 35.

The inlet side of the gas turbine 35 is connected to the combustor 10 and the discharge side is a heat exchanger 38 that is a preheating unit for premixed fuel.
Is connected.

The air compressor 36 takes in air from the atmosphere 109,
The air is compressed, and compressed air 110 is sent to the combustor 10.

When the load is applied to the gas turbine 35, the combustor 10 takes in the diffusion fuel 102 from the diffusion fuel system 4 and the premix fuel 10 from the premix fuel system 5 via the heat exchanger 38.
3, the compressed air 110 is taken in from the air compressor 36 and burned, and the combustion gas 111 which is a high-temperature gas is sent to the gas turbine 35.

The gas turbine 35 takes in the combustion gas 111 from the combustor 10, converts the thermal energy into mechanical energy, and rotates the air compressor 36 and the generator 37 with the power. In addition, the high-temperature exhaust gas 112
Is supplied to the heat exchanger 38 as a heating medium for the premixed fuel 103.

In the heat exchanger 38, an intermediate part of the premixed fuel system 5 and the exhaust gas 112 of the gas turbine 35 are inserted,
Heat exchange is performed between the premixed fuel 103 and the high-temperature exhaust gas 112, and the exhaust gas 112 after the heat exchange flows to a post-processing means (not shown). The amount of exhaust gas supplied to the heat exchanger 38 is, as shown in FIG.
28 is controlled by controlling the heating medium controller 31.

Generally, when the load on the gas turbine 35 increases, the pressure of the premixed fuel 103 increases, so that the heating limit temperature of the premixed fuel 103 increases accordingly. On the other hand, when the load on the gas turbine 35 increases, the temperature of the exhaust gas 112 also increases. Therefore, in the embodiment shown in FIG.
The premixed fuel 103 can be effectively preheated by using the exhaust gas 112 of the above, and the evaporation can be promoted.

Further, when a plurality of gas turbines 35 are installed, the premixed fuel 103 can be more effectively preheated by using the exhaust gas 112 of each gas turbine 35.

The other structure and operation of the embodiment shown in FIG.
This is the same as the oil-fired gas turbine shown in FIG.

FIG. 3 is a system diagram showing another specific embodiment of the preheating means for premixed fuel.

In the embodiment shown in FIG. 3, a heat exchanger 39 is provided on the discharge side of the air compressor 36. In the heat exchanger 39,
The premixed fuel system 5 and the compressed air 110 are inserted in the middle part of the premixed fuel system 5 so that the premixed fuel 103 and the compressed air 110 exchange heat, and the compressed air 110 after the heat exchange enters the combustor 10. I have.

In the embodiment shown in FIG. 3, the compressed air 11 which is the air discharged from the air compressor 36 is used as the heating medium for the premixed fuel 103.
Uses 0. The discharge temperature of the compressed air 110 depends on the capacity of the air compressor 36, but is currently less than about 400 ° C. at present. Therefore, the premixed fuel 103 can be sufficiently preheated using the compressed air 110. Also, compressed air 1
The temperature of the gas turbine 10 is the same as that of the exhaust gas 112 described above.
The gas turbine 35
, It is possible to increase the temperature of the premixed fuel 103 in accordance with the load.

Further, in the case of the regenerative cycle type gas turbine, the discharge temperature of the compressed air is higher by 100 to 150 ° C. than in the simple cycle type gas turbine shown in FIG. Accordingly, in the regenerative cycle gas turbine, the premixed fuel 103 can be more effectively preheated by using the compressed air to accelerate the evaporation, and the length of the preevaporation premixer 23 shown in FIG. It is possible to further reduce the length.

In the case of an oil-fired gas turbine in which a plurality of air compressors 36 are installed, it is more effective to use a heat exchanger 39 provided on the discharge side of each air compressor 36.

The other structure and operation of the embodiment shown in FIG.
This is the same as the embodiment shown in FIG.

FIG. 4 is a system diagram showing an embodiment of a specific example of a preheating means for premixed fuel.

The embodiment shown in FIG. 4 shows an embodiment in which a preheating means for premixed fuel is incorporated in an oil-fired gas turbine of a combined cycle, and an air compressor 36 and a steam turbine 40 And the generator 37 are connected.

The steam turbine 40 is provided with a condenser 41. The steam turbine 40 has a water supply system 42 having a water supply pump 44 and a steam system having a steam flow control valve 45.
A waste heat recovery heat exchanger 46 is connected via 43.

The waste heat recovery heat exchanger 46 is connected to the gas turbine 35 through an exhaust gas system 47 and is connected to a chimney 49 through a flue 48. Further, an extraction system 50 having an extraction flow control valve 52 in the waste heat recovery heat exchanger 46, and an extraction return system
51 and a heat exchanger 53 which is a means for preheating the premixed fuel.
Is connected.

The heat exchanger 53 is inserted with a portion in the middle of the premixed fuel system 5 and the bleed air 115 extracted from the waste heat recovery heat exchanger 46 so that the premix heat 103 and the bleed air 115 exchange heat. It has become.

In the embodiment shown in FIG. 4, the steam used as the power for the steam turbine 40 is used for heat storage in a condenser 41, then is pumped by a feedwater pump 44, passes through a feedwater system 42, and is passed through a wastewater recovery heat exchanger 46. Sent to This waste heat recovery heat exchanger 46 has a gas turbine through an exhaust gas system 47.
The high-temperature exhaust gas 112 discharged from 35 is sent. Then, the heat 113 exchanges heat between the water 113 sent from the water supply system 42 and the high-temperature exhaust gas 112 in the waste heat recovery heat exchanger 46, so that the water 113 is vaporized. Through the steam turbine 40 to do the work. On the other hand, the exhaust gas 112 emitted from the waste heat recovery heat exchanger 46 passes through the flue 48 and is discharged from the chimney 49.

A part of the steam 114 is extracted from the waste heat recovery heat exchanger 46, and the bleed air 115 is sent to the heat exchanger 53 through the bleed air system 50. A part of the premixed fuel system 5 is inserted into the heat exchanger 53.
103 and the high-temperature bleed air 115 exchange heat, and the premixed fuel 103
Is preheated and supplied to the combustor 10. The bleed air 115 after heat exchange in the heat exchanger 53 is returned to the waste heat recovery heat exchanger 46 through the bleed air return system 51.

In the combined cycle plant, since a part of the steam 114 can be easily taken out from the waste heat recovery heat exchanger 46, the premix fuel 103 is effectively preheated by using the bleed air 115 to promote evaporation. Becomes possible.

In the case of a combined cycle plant in which a plurality of waste heat recovery heat exchangers 46 are installed, a part of the steam 114 is extracted from one waste heat recovery heat
03 may be used as a heating medium, or a part of the steam 114 may be extracted from a plurality of waste heat recovery heat exchangers 46 and used.

The other structure and operation of the embodiment shown in FIG.
This is the same as the embodiment shown in FIG.

Next, FIG. 5 is a system diagram showing another embodiment of the preheating means for premixed fuel.

In the embodiment shown in FIG. 5, a heat exchanger 57 is connected to the steam turbine 40 instead of the waste heat recovery heat exchanger 46 of the embodiment shown in FIG.

The heat exchanger 57 is connected to the steam turbine 40 via an extraction system 54 having an extraction flow control valve 56, and is connected to the condenser 41 of the steam turbine 40 via an extraction return system 55. Further, a part of the premixed fuel system 5 is inserted into the heat exchanger 57.

In the embodiment shown in FIG.
A part of the steam 114 is taken out from 40, and the bleed air 116 is sent to the heat exchanger 57 through the bleed air system 54. The bleed air 116 after heat exchange is supplied to the combustor 10, and the bleed air 116 after the heat exchange is supplied to the condenser 41 through the bleed air return system 55.

Other configurations and operations of the embodiment shown in FIG. 5 are the same as those of the embodiment shown in FIG.

FIG. 6 is a system diagram showing still another embodiment of the preheating means for premixed fuel.

In the embodiment shown in FIG. 6, a water supply system 42 from a condenser 41 of a steam turbine 40 of a combined cycle plant to a waste heat recovery heat exchanger 46 is provided with two heat exchangers 60, 6
4 is connected.

One heat exchanger 60 is a water supply pump in the water supply system 42.
The steam turbine 40 is connected to the steam turbine 40 via a bleed air system 58, and further connected to the condenser 41 of the steam turbine 40 via a bleed air return system 59.

The other heat exchanger 64 is connected to a downstream side of the heat exchanger 60 in the water supply system 42 via a branch water supply system 61 having a water supply flow rate control valve 63, and a condenser 41 of the steam turbine 40.
Is connected via a water supply return system 62. A part of the premixed fuel system 5 is inserted into the heat exchanger 64.

In the embodiment shown in FIG. 6, in one of the heat exchangers 60 on the downstream side of the water supply pump 41 in the water supply system 42, the water 11 is supplied.
3 and the bleed air 116 extracted from the steam turbine 40 and supplied through the bleed air system 58 are subjected to heat exchange, and the water 113 is heated. The bleed air 116 after heat exchange with the water 113 is a bleed return system.
It is returned to the condenser 41 of the steam turbine 40 through 59.

The other heat exchanger 64 receives hot water through the branch water supply system 61.
The premix fuel 103 and the hot water 117 undergo heat exchange, and the premix fuel 103 is preheated by the hot water 117, and the preheated premix fuel 103 is sent to the combustor 10. The hot water 117 after heat exchange with the premixed fuel 103 is returned to the condenser 41 of the steam turbine 40 through the feedwater return system 62.

Therefore, also in the embodiment shown in FIG. 6, the premixed fuel 103 can be preheated by using the bleed air 116 of the steam turbine 40 as a heating medium, and the evaporation can be promoted.

The other structure and operation of the embodiment shown in FIG.
This is the same as the embodiment shown in FIGS. 4 and 5.

FIG. 7 is a system diagram showing still another embodiment of the means for preheating the premixed fuel.

In the embodiment shown in FIG.
, And a power system 68 is connected via a transformer 66 and a circuit breaker 67. The generator 37 has a transformer 69 and a circuit breaker 70.
And the in-house system (about 6000V) 71 is connected via

On the other hand, the premixed fuel system 5 is provided with an electric heater 73 as preheating means for premixed fuel. This electric heater
73 is connected to the in-house system 71 via a wiring 72.

In the embodiment shown in FIG. 7, the electric power supplied from the in-house system 71 to the electric heater 73 is controlled through a thyristor (not shown) or the like, and the pre-mixed fuel 103 can be appropriately preheated by the electric heater 73. .

Further, in the embodiment shown in FIG.
Also, at the time of startup, by supplying electricity to the electric heater 73 from the electric power system 68, the premixed fuel 103 is preheated by the electric heater 73, and the premixed fuel system 5 can be easily warmed up.

In the present invention, as the preheating means for the premixed fuel, the heat exchangers and electric heaters shown in FIGS. 2 to 7 may be used together, and gas such as city gas or propane gas may be used instead of the electric heater. May be used as a heat source.

[Effect of the Invention] According to the invention described in claim 1 of the present invention described above,
Since the premixed fuel is preheated by the heating medium and supplied to the preevaporation premixer of the combustor, the premixed fuel sprayed in the preevaporation premixer evaporates in a short time and is compressed with compressed air. Since the premixed fuel that has been mixed, burned, and preheated is at a high temperature, the surface tension of the fine particles of the premixed fuel is reduced, and as a result, the evaporation is accelerated, so that lean premixed combustion can be reliably realized. Therefore, there is an effect that the NOx generation amount can be significantly reduced, and since the premixed fuel can be evaporated in a short time, the length of the preevaporation premixer can be shortened. This has the effect that the spontaneous ignition of the premixed fuel can be surely prevented.

According to the second aspect of the present invention, the compressed air sent to the pre-evaporation pre-mixer is heated and mixed with the pre-mixed fuel. As a result, the pre-mixed fuel is heated by the heated compressed air. Since the evaporation of the pre-evaporation is promoted, lean premixed combustion can be reliably realized, so that the NOx generation amount can be significantly reduced and the length of the pre-evaporation pre-mixer can be shortened. There is an effect that the spontaneous ignition of the premixed fuel can be surely prevented.

Further, according to the third aspect of the present invention, the wall surface of the pre-evaporation pre-mixer is heated to supply the pre-mixed fuel. Since the mixed fuel is sprayed and the evaporation of the premixed fuel is promoted,
Lean premixed combustion can be reliably realized, so the amount of NOx generated can be significantly reduced, and the length of the preevaporation premixer can be shortened, so that the spontaneous ignition of the premixed fuel in the preevaporation premixer is ensured Has an effect that can be prevented.

According to the invention of claim 4 of the present invention, the wall surface of the pre-evaporation pre-mixer is heated, the pre-mixed fuel is pre-heated by the heating medium, and the compressed air sent to the pre-evaporation pre-mixer is further heated. As a result of supplying the premixed fuel and the compressed air to the preevaporation premixer and mixing them, evaporation of the premixed fuel is further promoted, so that lean premixed combustion can be more accurately realized, Therefore, the amount of generated NOx can be significantly reduced and the length of the pre-evaporation pre-mixer can be shortened, so that the spontaneous ignition of the pre-mixed fuel in the pre-evaporation pre-mixer can be surely prevented.

According to the fifth aspect of the present invention, since the preheating means for preheating the premixed fuel is provided upstream of the premixed fuel nozzle, there is an effect that the method of the present invention can be accurately executed. .

Further, according to the invention of claim 6 of the present invention, since the heating means for heating the compressed air sent to the pre-evaporation pre-mixer is provided, the method of the present invention can be properly carried out by this fuel supply system. There is an effect that can be done.

Further, according to the invention of claim 7 of the present invention, since the heating means for heating the wall surface of the pre-evaporation pre-mixer is provided, the above-mentioned method of the present invention can be accurately carried out also by this fuel supply system. effective.

According to the invention of claim 8 of the present invention, a heating means for heating the wall surface of the pre-evaporation pre-mixer is provided, and a pre-heating means for pre-heating the pre-mix fuel is provided upstream of the pre-mix fuel nozzle. Further, since the means for heating the compressed air to be sent to the pre-evaporation pre-mixer is provided, there is an effect that the method of the present invention can be more accurately performed.

Furthermore, according to the invention of claim 9 of the present invention,
Since a heat exchanger for exchanging heat between the exhaust gas of the gas turbine and the premixed fuel is provided as a means for preheating the premixed fuel, the method of the present invention can be performed more reliably.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a gas turbine system for carrying out the method of the present invention, in which a combustor is cut in a radial direction, and the relationship between the combustor and various systems connected thereto is shown. 2 to 7 are system diagrams showing specific examples of the preheating means for premixed fuel, and FIG. 8 is a fuel pressure-temperature gas-liquid boundary diagram. 1 ... fuel system, 2 ... fuel pump, 4 ... diffusion fuel system, 5 ... premixed fuel system, 7, 8 ... fuel flow control valve,
9: Fuel controller, 10: Combustor, 15: Combustor sub-chamber, 16: Combustor main chamber, 18: Diffusion fuel nozzle, 22
…… Premixed fuel nozzle, 23 …… Pre-evaporation premixer, 24 ……
Compressed air inlet, 25… Air passage for compressed air, 26… Preheating means for premixed fuel, 27… Heating medium supply pipe, 28…
Heating medium flow control valve, 29: Fuel pressure gauge, 30: Fuel thermometer, 31: Heating medium controller, 32: Fuel pressure-temperature gas-liquid boundary diagram, 33: Compressed air heating means A first electric heater, 34... A second electric heater as heating means for the wall surface of the pre-evaporation pre-mixer, 35.
36 ... Air compressor, 37 ... Generator, 38 ... Exhaust gas-premixed fuel heat exchanger, 39 ... Compressed air-premixed fuel heat exchanger, 40 ... Steam turbine, 42 ... Water system, 43 ……
Steam system, 44… Feed water pump, 46… Waste heat recovery heat exchanger, 47… Exhaust gas system, 50… Bleed system, 51… Bleed return system, 52… Bleed flow control valve, 53… Bleed-premixed fuel heat exchanger, 54 ... Bleed system, 55 ... Bleed return system, 56 ... Bleed flow control valve, 57 ... Bleed-premixed fuel heat exchanger, 58 ... Bleed system, 59 …… Bleed return system, 60…
... heat exchanger for bleed air-feed water, 61 ... branch water supply system, 62 ...
Feed water return system, 63: Feed water flow control valve, 64: Heat exchanger for feed water-premixed fuel, 68 ... Power system, 71: In-house system, 72: Wiring, 73: Heating of premixed fuel Electric heater, 100, fuel, 102, diffusion fuel, 103, premixed fuel, 104, air, 105, compressed air, 108, heating medium, 109, atmosphere, 110, compression Air, 111: Combustion gas, 112: Exhaust gas, 113: Water sent to the waste heat recovery heat exchanger, 114: Steam, 115: Extracted air extracted from the waste heat recovery heat exchanger, 116: … Extracted air extracted from the steam turbine, 117 …… hot water.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Haruo Urushiya 3-1-1, Sachimachi, Hitachi-shi, Ibaraki Hitachi, Ltd. Hitachi Plant (72) Inventor Kazuhiko Kumada 3-1-1, Sachimachi, Hitachi-shi, Ibaraki No. 1 Inside Hitachi, Ltd. Hitachi Plant (72) Inventor Tomio Kuroda 3-1-1 Sachimachi, Hitachi City, Ibaraki Prefecture Inside Hitachi Plant, Hitachi Plant (72) Inventor Katsukuni Kuno 3 Sachimachi, Hitachi City, Ibaraki Prefecture 1-1 1-1, Hitachi, Ltd.Hitachi Plant, Hitachi, Ltd. (72) Inventor Yoichi Yoshinaga 502, Kandate-cho, Tsuchiura-shi, Ibaraki Pref. Machinery Research Laboratory, Hitachi, Ltd. (56) References JP-A-54-55214 (JP, A) JP-A-1-155032 (JP, A) Jpn. JP, U) Tokuoyake Akira 59-131264 (JP, B2) (58 ) investigated the field (Int.Cl. ^6, DB name) F23R 3/30 F02C 7/224 F02C 7/08 F23R 3/34

Claims (9)

(57) [Claims] 1. A fuel supply method for an oil-fired gas turbine for supplying a premixed fuel when a load is applied to the gas turbine, in addition to the diffusion fuel to the combustor, wherein the premixed fuel is preheated by a heating medium. A fuel supply method for an oil-fired gas turbine, comprising supplying the preheated premixed fuel to a preevaporation premixer of a combustor. 2. A fuel supply method for an oil-fired gas turbine for supplying a premixed fuel when a load is applied to the gas turbine, in addition to the diffusion fuel to the combustor, the compression fed to a pre-evaporation premixer in the combustor. A method for supplying fuel for an oil-fired gas turbine, comprising heating air and mixing the heated compressed air with a premixed fuel. 3. A fuel supply method for an oil-fired gas turbine which supplies a premixed fuel when a load is applied to the gas turbine in addition to the diffusion fuel to the combustor. A fuel supply method for an oil-fired gas turbine, comprising heating and supplying a premixed fuel. 4. A fuel supply method for an oil-fired gas turbine which supplies a premixed fuel when a load is applied to the gas turbine in addition to the diffusion fuel to the combustor. Heating and preheating the premixed fuel with a heating medium, further heating the compressed air sent to the preevaporation premixer,
A fuel supply method for an oil-fired gas turbine, comprising supplying and mixing the preheated premixed fuel and the heated compressed air to the preevaporation premixer. 5. A compressor that takes in air and discharges compressed air, a combustor that burns by supplying fuel and compressed air from the compressor, and a gas turbine that is driven by supplying combustion exhaust gas from the combustor. Wherein the combustor includes a premixed fuel nozzle that ejects the supplied premixed fuel, an introducing unit that guides compressed air discharged from the compressor, and a gas turbine. A pre-evaporation pre-mixer that mixes compressed air and fuel from the pre-mixed fuel nozzle and guides the mixture to a combustion chamber, and a pre-heating unit that pre-heats pre-mixed fuel supplied to the pre-mix fuel nozzle. Gas turbine equipment. 6. A compressor that takes in air and discharges compressed air, a combustor that burns supplied fuel and compressed air discharged from the compressor, and is driven by the supply of combustion exhaust gas from the combustor. Gas turbine equipment comprising: a premix fuel nozzle for injecting the supplied premix fuel; an introduction means for introducing compressed air discharged from the compressor; and A pre-evaporation pre-mixer that mixes the compressed air by the introduction means and the fuel from the pre-mixed fuel nozzle and guides the fuel into the combustion chamber; and a means for heating the compressed air by the introduction means and mixing with the pre-mixed fuel. Gas turbine equipment characterized by the above-mentioned. 7. A compressor that takes in air and discharges compressed air, a combustor that burns supplied fuel and compressed air discharged from the compressor, and is driven by the supply of combustion exhaust gas from the combustor. Gas turbine equipment comprising: a premix fuel nozzle for ejecting the supplied premix fuel; an introduction means for introducing compressed air discharged from the compressor; and A pre-evaporation pre-mixer that mixes the compressed air by the introduction means and the pre-mixed fuel from the pre-mixed fuel nozzle and guides the mixture to a combustion chamber, and heating means for heating a component of the pre-evaporation pre-mixer Gas turbine equipment characterized by the following. 8. A compressor that takes in air and discharges compressed air, a combustor that burns supplied fuel and compressed air discharged from the compressor, and is driven by the supply of combustion exhaust gas from the combustor. Gas turbine equipment comprising: a premix fuel nozzle for injecting the supplied premix fuel; an introduction means for introducing compressed air discharged from the compressor; and A pre-evaporation pre-mixer that mixes the compressed air by the introduction means and the pre-mixed fuel from the pre-mixed fuel nozzle and guides the mixture to the combustion chamber; a pre-heating means for pre-heating the pre-mixed fuel supplied to the pre-mixed fuel nozzle; Gas turbine equipment comprising: heating means for heating compressed air; and heating means for heating a component of the pre-evaporation pre-mixer. 9. The oil-fired gas turbine equipment according to claim 5, wherein a heat exchanger for exchanging heat between the exhaust gas of the gas turbine and the premixed fuel is installed as the preheating means for the premixed fuel. .