JPS63280826A - Gas turbine fuel supply system - Google Patents

Abstract

PURPOSE:To heighten the degree of freedom of the regulation of a stable combustion at what has a burner using more than two kinds of fuels including a liquid fuel and a gas fuel by dividing a fuel supply line into plural ones and making it possible to set the changeover of fuels and the ratio of mixed burning and exclusive burning. CONSTITUTION:The supply line of a liquid fuel e and a gas fuel i is divided into lines A-1, B-1 on a pilot side and lines A-2, B-2 on a main side, and they are respectively connected to a burner 1. Liquid fuel flow quantity regulation valves 15 and liquid fuel cutting-off valves 16 are provided at respective lines A-1, A-2, and at the same time, gas fuel flow quantity regulation valves 45 and gas fuel cutting-off valves 46 are provided at lines B-1, B-2, and the fuel quantity distribution (the pilot side/the main side) regarding respective fuels e, i is controlled by controlling respective flow quantity regulation valves 15, 45. And, fuel is made to burn by supplying compressed air from a compressor 2c to the burner 1 of this kind, and a turbine 2a is made to drive by means of a high-pressured and high-temperature gas thus generated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention supplies fuel of class 2s or higher including liquid fuel and gaseous fuel to a combustor, and drives a gas turbine with the combustion gas obtained here. This invention relates to a gas turbine fuel supply system.

[Conventional technology]

Conventional fuel supply systems for gas turbines include an example of a two-fuel mixed combustion system shown in FIG.
There is an example of an alcohol-based fuel co-combustion system shown in FIG. 12, which is No. 7-215913).

Figure 11 shows that fuel ■ (liquid fuel ■) and fuel ■ (gaseous fuel) are supplied to the combustor l by different fuel supply systems. ZJL flow rate adjustment valve 15 and cutoff valve 16, flow rate vI4 control valve 45
A shutoff valve 46 is provided. Note that 2a is a gas turbine, 2b is a generator, and 2c is a compressor, which together constitute a gas turbine power generation system. ■ indicates air.

In the case of the gas turbine 2a having a similar configuration, when the gas turbine 2a stops, each shutoff valve 16, 46 is fully closed and the fuel supply is stopped.

In Fig. 12, (1) When the exhaust gas temperature of the gas turbine 2a is low and gasification is insufficient, such as during the period from system startup to low load, line (fuel supply system) A is The liquid fuel ■ is supplied to the combustor 1.

(2) Then, when the amount of gas generated in the reactor 7 reaches a predetermined value, the generated gas and liquid fuel are switched from line A to line B. Basically, the system is such that the gas turbine 2& can be operated at its rated value using generated gas and liquid fuel, respectively.

(3) When the gas turbine 2a is stopped, the fuel cutoff and nitrogen gas discharge are performed by sequentially controlling the gas fuel cutoff valve 14 and the nitrogen gas purge valve 24 in line D.

In addition, in FIG. 12, in order to operate the reactor 7,
The temperature detector T detects the exhaust gas temperature of the gas turbine 2a at several hundred degrees.
The ninth thing that needs to be detected by EX is the temperature detector TEI.
Gaseous fuel line B is used when the detected value reaches a predetermined temperature.

The gaseous fuel is returned to the fuel side through the temporary gas fuel bypass valve 12 and the bypass cutoff valve 13, but when the detection output of the temperature detectors TEJ and TE2, that is, the detection concentration of the gas temperature gas concentration detector S1 reaches a predetermined value. , the gas fuel cutoff valve 14 is fully opened, and the gas fuel flow rate control valve 26 is fully closed.
Gas fuel pipe/four pipe regulating valve 12 and liquid fuel flow regulating valve 1
The valve opens in conjunction with the closing operation in step 5.

[Problem that the invention seeks to solve]

The conventional examples shown in FIGS. 11 and 12 described above have the following problems.

(b) In Fig. 11, the startup of the gas turbine 2a (
When the load is increased (ignition/speed increase), the fuel enters a mixed combustion state during the switching, but since the supply system has one each for fuel I and fuel H, the degree of freedom in stable combustion adjustment is low.

(b) In Fig. 12, when alcohol-based fuel is used, if the fuel is shut off by stopping the gas turbine 2a, the methanol remaining in the liquid fuel line (from the shutoff valve to the fuel nozzle) will evaporate due to turbine residual heat. At the initial stage of startup, %'apour 1ock occurs, causing a delay in ignition.

Therefore, the present invention proposes a combination combustion of two or more types of multiple fuels → exclusive combustion,
It is an object of the present invention to provide a gas turbine fuel supply system that can increase the degree of freedom in stable combustion adjustment when switching from single combustion to mixed combustion, and can prevent paper leaks that occur when restarting a gas turbine.

[Means for solving problems]

In order to achieve the above object, the present invention supplies two or more types of fuel including liquid fuel and gaseous fuel to a combustor, and drives a gas turbine with the combustion gas obtained here, in which the fuel is supplied to the combustor. The fuel supply system is divided into a plurality of parts, and the fuel can be switched and the proportion of mixed combustion and exclusive combustion can be set.

[Effect]

Since the present invention is configured as described above, the following effects can be obtained. Since the fuel supply system is divided into a plurality of parts, it is possible to increase the degree of freedom in combustion stability in switching between mixed combustion and exclusive combustion of a plurality of fuels of class 2a or higher. In addition, if you use a separate fuel with low volatility and start and stop the gas turbine, the vane 4 will be activated when the gas turbine is restarted.
0. It is possible to prevent this from occurring and causing a delay in ignition.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. Figure 1 shows the first embodiment of the two-fuel mixed combustion system, but the dedicated combustion system is one of the mixed combustion systems.
Therefore, this system can achieve both single-firing and mixed-firing conditions. For convenience of explanation, Fuel I (liquid fuel ■) and Fuel ■ (gaseous fuel) are selected, but Fuel I and ■ are not fixed, but cover all types of fuel. Filtration and pressure FA under specified conditions
For the prepared fuel, the fuel supply system for both fuel 11 and fuel is connected to the main pilot side system (indicated as A-J, B-1) and the main side system (indicated as A-2, B-2). It is configured so that it is divided into two parts (n) and supplied to the combustor 1.

Below, the above-mentioned systems A-J, A-J, B-J, B-, ? is called a line. Lines A-1 and 1-2 are provided with a liquid fuel flow rate adjustment valve 15 and a liquid fuel cutoff valve 16, respectively, and lines B-1 and B-2 are provided with a gaseous fuel flow rate adjustment valve 4, respectively.
5 and a gas fuel R cutoff valve 46. In addition, the broken lines in the figure indicate that the same systems are installed in parallel, 15A is the main side liquid fuel total flow rate adjustment valve, 45A is the main side gaseous fuel total flow rate adjustment valve, TI (7, TEJ are both It is a temperature detector.

In Figure 1, when setting the fuel supply conditions (source pressure, etc.) separately for the pilot side and the main side,

Condition control equipment (valves, filters, etc.) shall be installed at A. The fuel amount distribution for fuel 1 (pyro, g side/main side) is performed by operating valve 15/valve 15. When the main side has multiple lines, the main side total flow rate is controlled by the valve 2.5A, and the main line distribution is adjusted by the plurality of valves 15. As for fuel, the relationship between valve 45/valve 45/valve 45A is the same.

FIG. 2 is for explaining the combustion situation at the rated point in FIG. 1, and shows a mixed combustion situation in which fuel I is started and fuel ■ is used. When starting with fuel ■, reverse the combination of conditions.

Figure 3 shows the co-firing situation in Figure 2 in the operating range of the gas turbine 2 m (start-up → rated output). However, these are only examples, and are intended to show an image of the actual turbine 2a, and there are other variations of heat dissipation. It goes without saying that all such variations are within the scope of the present invention "as long as they are obtained by dividing the fuel supply into pilot and main."

In Figure 3...(7) Fuel ■・Pilot) After starting the gas turbine at (Ip), fuel H・Main (IIM)
is input to obtain the total heat amount of the rated output. (b) It is also possible to use fuel (lip) in the mid-operation range and then add 11M. At that time, other than keeping Ipt constant ■? is reduced to Ip' and the difference is Il
p may be added. When securing the minimum stable gas turbine heat fcR with both the fuel (1) and the fuel (2), the above will be the above P], and with only Ip, the above will be the same. Fuel: In the case of dedicated combustion, set Ip' to zero and increase IIM accordingly.

Fig. 3 Gi)... After starting the gas turbine with fuel ① and 4 pilots (Ip), fuel I and main C1w) are introduced up to a predetermined flow rate IIk. Then fuel ■ Nona Zero,)
Should I input (flp) and main (Lg) together?
is input to obtain the total heat amount of the rated output. At that time, in addition to keeping Ip constant, reduce Ip to It' and m
p may be added. Gas turbine stable minimum heat ficR
is secured by only Ip or the sum of Ip and ■p. Fuel ■・
In the case of dedicated firing, both (I P'+ I M') are set to zero, and IBM is increased accordingly.

Figure 3 (jiD...After starting the gas turbine 2a with IP, IM is turned on. Further, Ilp and IIM are increased to make the total heat amount of the rated output. When rp is reduced to zero in the middle operation range, Switch to Ilp to ensure zero fuel heat.CR is (Ilp, II- or (IIP,
This corresponds to the combination of I-. Fuel■・I for thick roasting
Let M' be zero, and increase ■father-in-law accordingly. (1
) to 1liD during fuel switching, the temperature sensor TE
The turbine outlet temperature, which is the detected value of X, or the turbine inlet temperature, which is the detected value of the temperature detector TEO, is controlled to be constant.

According to the first embodiment of the present invention described above, the following effects can be obtained.

+11 Fuel supply system A-1, A-2, B-1゜B
Divided into -2 and multiple parts, -1゜B-
1 and main lines B-2 and A-2, 281
Combustion stability in switching between mixed combustion and exclusive combustion of multiple fuels as described above and the degree of freedom in combustion adjustment for NOx control can be improved.

(Part 1) On the other hand, when recovering waste heat from the exhaust gas of the gas turbine 2a into liquid fuel, converting it to gaseous fuel and utilizing latent heat and sensible heat will save fuel consumption and improve plant thermal efficiency. In this case, the technique (1) is used to first start the gas turbine 21 with liquid fuel and then perform mixed combustion or exclusive combustion with gaseous fuel.

(2) The above-mentioned method can be applied not only to highly volatile fuels such as alcohol-based fuels but also to general petroleum-based fuels.

However, for alcohol-based fuel, (starting/stopping) will be performed using auxiliary fuel (light, light oil, etc.), and the gas turbine 2
While the turtle is stopped, the remaining alcohol in the nozzle evaporates due to the residual heat from the gas turbine 2a, and when the turtle is restarted, the alcohol remaining in the nozzle evaporates. Preventing damage from occurring.

+2) -2 Flucoal fuel uses gas turbine exhaust heat to increase the amount of heat it retains and converts it into (steam/steam reformed or cracked gas)
However, by providing equipment equipped with (1) and (2), the degree of freedom in selecting fuel for the gas turbine 2a increases and fine control becomes possible.

+2)-3 gas turbine 2IL 12)-1, +2)-
2, and by constructing a steam turbine system with the remainder of the exhaust heat of the gas turbine 21 to form a combined cycle, it is possible to maximize the plant efficiency, but it can also be applied to this combined cycle power generation system.

In the first embodiment of the present invention, there may be one line, but if necessary, a plurality of lines may be used to further increase the degree of freedom in combinations of fuel distribution.

FIG. 4 shows a second embodiment of the present invention, and shows a first embodiment.
The figure shows gaseous fuel ■ heated by the exhaust gas of the gas turbine 2a.
The difference is that it is configured to be heated at step d. Note that △ and Mu indicate fuel supply condition control points, and ■ indicates a fuel main pipe.

FIG. 5 shows a third embodiment of the present invention, in which a gas turbine 2
With the exhaust gas of a, (7) liquid fuel ■ is transferred to the preheater 7a and the evaporator/
Heating/evaporating/superheating with heater 7b, (a) gaseous fuel■
This is an example of heating with the heater 7d. Specifically, the embodiment differs from the embodiment shown in FIG. 4 in the following points. That is, gaseous fuel lines BB-J and BB-2 are newly installed between the heater 7d that heats the gaseous fuel from the fuel main pipe and the combustor 1, and a gaseous fuel flow rate adjustment valve 26 is installed in the line BB-1. and a gaseous fuel cutoff valve 14, and a main side gaseous fuel total flow rate adjustment valve 26, a gaseous fuel flow rate adjustment valve 26, and a gaseous fuel cutoff valve 14 are provided in the line BB-2. In addition, 11 is pressure v! 4
40 is a gas fuel supply cutoff valve, 44 is a gaseous fuel cutoff valve, and 43 is a gaseous fuel bypass adjustment valve.

By configuring as shown in FIGS. 4 and 5, the sensible heat and latent heat of the fuel can be recovered as waste heat to increase the retained heat amount and save fuel consumption.

That is, gaseous fuel is processed in heater 7d, and liquid fuel is processed in preheater 7m and evaporator/heater 7b.

Further, the heater 7d and the evaporator/heater 7b are arranged with their high-temperature sides parallel to each other, and both utilize the high-temperature (detected value of the temperature detector TEX) gas turbine 2 exhaust gas.

In addition, at the initial stage of vaporization of liquid fuel, the shutoff valve 40 is fully closed, and the valve 44.
43 is fully opened to circulate the fuel back to the fuel tank. When the detected value of the temperature detector TRI, that is, the exhaust temperature reaches a predetermined value, the valve 40 is opened, and the valve 43t - closing valve 45, 45A is opened.
is operated in the open direction to supply fuel vapor to the gas turbine 2a.

FIG. 6 shows a modification of the present invention, that is, the relationship between a waste heat recovery heat exchanger and a gas turbine fuel supply system according to the present invention. A heat exchanger is shown, and FIG. 6(b) shows a heat medium type heat exchanger. In the figure, 60 is a heat medium heat converter, and 61 is a heat medium circulation pump.

Fig. 7 shows a combined cycle system according to the present invention in which a turbine fuel supply system is combined with an exhaust gas boiler section 3 to form a steam turpin system, and Fig. 7(a) shows a branch duct system; (d) shows a steam/heat medium integrated duct system. Note that the steam turbine system 7 is a reactor section 4, and the steam line 80 is a steam line. By configuring as shown in FIG. 7, waste heat recovery can be improved, thereby improving plant efficiency.

FIG. 8 shows the gas turbine fuel supply system according to the present invention used for alcohol fuel, in which the following four types of fuel are supplied between the methanol reforming reactor (cracking/steam reforming) 7 and the combustor 1. A line is formed, i.e.
Main side auxiliary liquid fuel line AA-7, main side auxiliary liquid fuel line AA-2, side methanol line A-J1 main side methanol life -2,
Nozairo, side methanol steam 2-in B-1, main side methanol steam line B-2, pilot side reforming (cracking/steam reformed gas) line BB-1, main side reforming (cracking/steam reforming gas) Line BB-2 is installed, 2 in A
A-2 and AA-2 are provided with n auxiliary fuel flow rate g4 regulating valve 35 and auxiliary fuel cutoff valve 36, respectively, and lines A-1 and A
−，? are provided with an auxiliary fuel flow rate adjustment valve 15 and an auxiliary fuel cutoff valve 16, respectively; lines B-1 and B-2 are provided with a methanol vapor flow rate adjustment valve 45 and a methanol vapor cutoff valve 46, respectively; ,BB-,? are provided with a reforming flow rate regulating valve 26 and a reforming cutoff valve 14, respectively.

In addition, g is nitrogen gas main pipe, 24-1.24-2.24-
1', 24-2' are nitrogen gas parts valves, 1σ is a pressure regulating valve (source pressure), 12 is a reforming bypass regulating valve, 13 is a reforming cutoff valve, 4 is a reactor fuel flow regulating valve, 42 is a reactor fuel cutoff valve, 47 is a reforming supply cutoff valve, 7C is a reactor/superheater, and 18 is a reactor drain valve.

By configuring as shown in Fig. 8, thick firing or mixed firing can be done as needed. The gas turbine 21 is first started with auxiliary fuel (kerosene, light oil, etc.), and then switched to methanol under certain conditions. When switching, as long as the combustor 1 is stable, either (), flat, or (main) may be performed first. Temperature detector TEX or TE during fuel switching
Control is performed so that the detected value of O is constant. The switching conditions can be freely selected such as no-load rating or partial load below the rated load. Since methanol can be evaporated at temperatures below 200°C, it can be used with a relatively low load.

After methanol switching, methanol is supplied to the preheater 7m and the evaporator/heater 7b from the valve 11, and the methanol is circulated to the return fuel tank. At this time, valves 40, 41
．． The valve 42 is fully closed, and the valve 44 is fully open.The valve 43 is operated in accordance with methanol evaporation. If the detected value of the temperature detector TEI reaches a temperature at which methanol vapor is steadily generated, the valve 4 is closed.
0.46 and (46) are fully opened, and valves 45 and (45
) and the valve 43, a transition is made to co-combustion of methanol and methanol vapor or exclusive combustion of methanol vapor. The procedure at that time is the same as shown in FIGS. 2 and 3. When the detection output of the temperature detector TEX reaches the reforming temperature and line BB is used, open the valves 42, 41, 13° 12 from the methanol vapor state or once return to methanol combustion (exclusive combustion). Reactor/7J
Activate the O heater 7c.

When the detected value of the temperature detector TE2 at the outlet of the reactor/heater 7c and the detected value of the gas concentration detector S1 reach predetermined values, the second
According to the steps shown in the figure and FIG. 3, co-firing methanol or methanol vapor and reformed gas (separation/steam reforming) or exclusively burning the reformed gas is carried out.

However, in this case, Figures 2 and 3 will be used with () being replaced with the switched fuel and (2) with the switched fuel.

When the gas turbine 2a is stopped, the gaseous fuel is switched to auxiliary fuel (AA, y-in) and then the fuel is cut off. The same applies when using liquid methanol. In order to fill the gaseous fuel line with nitrogen gas, the shutoff valve 24-1 (or 24-2) is opened. Shutoff valve at the same time? 4-J'(
or 24-2') also opens to complete filling.

Figure 9 shows the relationship between the gas turbine fuel supply system according to the present invention and each reactor type.
9 shows a direct thermal reactor, FIG. 9(b) shows a thermal medium reactor, and FIG. 9(, ) shows an adiabatic reactor.

In the figure, 60 is a heat medium heat exchanger, 61Fi heat medium circulation pump, 70 is a reaction gas heat exchanger, and 71 is a circulation proa.

Direct heat exchange reactor as shown in Figure 9 (a), (0),
The present invention can be applied to different reactors such as a thermal medium reactor and an adiabatic reactor.

In order to further improve waste heat recovery, what is the exhaust gas shown in Figure 10? If a steam turbine system is constructed by combining the inner parts 3, a combined cycle system can be formed, and the present invention is also applicable to these systems. Figure 10(d) shows the branch duct system, Figure 10(, ) shows the steam/heat medium integrated duct system,
Figure (f) shows an integrated steam/fuel duct system.

On the other hand, if it is necessary to save the amount of auxiliary fuel when starting a gas turbine, it is appropriate to switch to methanol (liquid) as described above, but if sufficient auxiliary fuel can be used, start with auxiliary fuel and then use methanol directly. The system will be switched to gaseous fuel to simplify control.

〔Effect of the invention〕

According to the present invention described above, it is possible to increase the degree of freedom in adjusting stable combustion in switching from mixed combustion to exclusive combustion and exclusive combustion to mixed combustion of two or more types of multiple fuels, and it is also possible to prevent vapor lock that occurs when restarting the gas turbine. A gas turbine fuel supply system can be provided.

[Brief explanation of drawings]

FIG. 1 is a schematic PJ diagram showing a first embodiment of the gas turbine fuel supply system according to the present invention, FIG. 2 is a diagram for explaining the combustion situation at the rated point in FIG. 1, and FIG. A diagram for explaining an example of mixed combustion when starting with fuel I in Figure 1,
FIG. 4 and FIG. 5 are schematic configuration diagrams showing second and third embodiments of the gas turbine fuel supply system according to the present invention, respectively, and FIG. FIG. 7 is a diagram showing the combined cycle system configuration, and FIG. 8 is a diagram showing the usage status of liquid fuel and gaseous fuel in the methanol reforming reactor (cracking/steam reforming) of the embodiment of the present invention. 9 is a diagram showing the relationship between each reactor type and the fuel system of the present invention, FIG. 10 is a diagram showing a combined cycle system configuration, and FIG. 11 is a diagram showing a conventional two-fuel co-combustion system. FIG. 12 is a diagram showing a conventional alcohol-based fuel co-combustion system. b...Air, e...Liquid fuel, f...Return fuel tank, g...Nitrogen gas main pipe, h...Auxiliary fuel tank, 1...Combustor, 2...Gas Turbine generator, 2a
...Gas turbine, 2b... Generator, 2C... Compressor, 3... Exhaust gas dealer section, 7... Reactor section, 1
0...Pressure regulating valve (source pressure), 11...Pressure regulating valve (
supply pressure), 12... gaseous fuel bypass adjustment valve (Na2
), 13... Gaseous fuel cutoff valve (turtle 2), 14... Gaseous fuel cutoff valve (hidden 2), 15... Liquid fuel flow rate adjustment valve, 16... Liquid fuel cutoff valve, 18...・Reactor drain valve, TEJ, TE, ? ...Temperature detector, S...Gas 1 degree detector, 24-1, 24-1'...Nitrogen gas turbine (Na1 gas fuel line), 24-2, 2
4-2'... Nitrogen gas, 4-ji valve (floor 2 gas fuel line), 26... Gaseous fuel flow rate adjustment valve (Na2), 3
5... Auxiliary fuel flow rate adjustment valve, 36... Auxiliary fuel cutoff valve, 40... Gaseous fuel supply cutoff valve (PJll),
41... Reactor fuel flow rate adjustment valve, 42... Reactor fuel cutoff valve, 43... Gaseous fuel bypass adjustment valve (Nll
l), 44... Gaseous fuel cutoff valve (Nll), 45...
... Gaseous fuel flow rate adjustment valve (N (L 1 ), 46-...
Gaseous fuel cutoff valve (Na1), 47... Gaseous fuel supply cutoff valve (Magnetic 2). Applicant's representative Patent attorney Takehiko Suzue Figure 1 Figure 2 Starting position Constant motion GT operating range Rated output 60, Heat medium heat exchanger 61 - Heat medium circulation pump Figure 6 6〇 - Heat medium heat exchanger 70-Reactive gas heat exchange 61・
- Heat medium circulation pump 71 - Circulation proa 3 - 11 wandering heat boiler section 4 - 1 steam turbine system 80 - 1 steam line

Claims (1)

[Claims] In systems that supply two or more types of fuel including liquid fuel and gaseous fuel to a combustor and drive a gas turbine with the combustion gas obtained here, each fuel supply system that supplies the fuel to the combustor is divided into multiple parts. The gas turbine fuel supply system is configured such that the fuel can be switched and the ratio of mixed combustion and dedicated combustion can be set.