JP3785760B2 - Combustor control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control device for a combustor, and more particularly to a technique for reliably detecting a backfire and extinguishing a backfire early when a backfire occurs in a pre-evaporation premixing section.
[0002]
[Prior art]
As a conventional combustor such as a gas turbine, for example, as disclosed in Japanese Utility Model Publication No. 2-72334, 7 There is what is called a pre-evaporation premixing type as shown in FIG.
[0003]
The configuration of this prior art is illustrated in FIG. 7 Will be described.
The combustor 1 has two fuel injection valves, and the required fuel injection amount set according to the operating state is appropriately distributed to the first fuel injection valve 6 and the second fuel injection valve 9 for injection. It is a configuration.
[0004]
Fuel is injected from the first fuel injection valve 6 into the pre-evaporation pipe 3 serving as a pre-evaporation premixing passage portion of the combustor 1 and combustion air supplied via a compressor and a heat exchanger (not shown) is introduced. . In the pre-evaporation pipe 3, the injected fuel and combustion air are evaporated and mixed to form a pre-mixed gas, which is supplied to the combustion cylinder 4 which is the main combustion section. Further, the remaining injection amount obtained by subtracting the injection amount of the first fuel injection valve 6 from the required fuel injection amount is directly injected into the combustion cylinder 4 from the second fuel injection valve 9 and supplied from the pre-evaporation pipe 3. Combustion is performed in the combustion cylinder 4 together with the air-fuel mixture. Further, dilution air is introduced into the combustion cylinder 4 corresponding to the amount of fuel injected from both fuel injection nozzles, and the combustion cylinder 4 is controlled to burn within a certain range of lean state.
[0005]
In this way, a part or all of the fuel injection amount is pre-evaporated and premixed, and then burned in a certain range of lean state in the combustion cylinder, whereby the fuel is directly injected into the combustion cylinder with one fuel injection valve. Compared to the diffusion combustion type that injects, there is an advantage that the emission amount of NOx can be greatly reduced and good exhaust characteristics can be obtained.
[0006]
In such a pre-evaporation premix combustor, the temperature (Tp) in the pre-evaporation premix flow path is measured, and the first fuel injection valve and the second fuel injection valve are used as a function of the temperature (Tp). There is one that performs fuel flow distribution control.
[0007]
[Problems to be solved by the invention]
However, in such a conventional combustor control device, when a so-called backfire occurs in which the flame in the combustion cylinder flows backward into the prevaporization premixing passage, the temperature of the prevaporization premixing passage increases abnormally. Until a flashback condition is detected, fuel flow control is performed so that the combustion cylinder can be maintained in a predetermined lean combustion state assuming that there is no flashback. However, since the flashback condition is not improved, there is a problem that the durability of the pre-evaporation premixing flow path component is lowered.
[0008]
The present invention was made paying attention to such a conventional problem, and by finding a backfire at an early stage from the temperature (increase rate) of the pre-evaporation premixing flow path, by performing appropriate extinguishing control, The object is to prevent the deterioration of the durability of the combustor parts and to solve the above problems.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention evaporates the fuel injected from the first fuel injection valve disposed near the combustor inlet and combusts between the combustor inlet and the combustion cylinder into which combustion air flows. A pre-evaporation premixing passage that is mixed with the production air and led to the combustion cylinder, and a second fuel injection valve for diffusion combustion is provided at the connection between the pre-evaporation premixing passage and the combustion cylinder, corresponding to the operating condition The required fuel injection amount to be set is appropriately distributed to the first fuel injection valve and the second fuel injection valve according to the normal fuel distribution setting means and injected, and the intake for dilution air introduced into the combustion cylinder is provided in the combustion cylinder A first combustor configured to detect the temperature of the pre-evaporation premixing passage and the second temperature detection to detect the combustor inlet temperature in the combustor that is opened and configured to combust at a predetermined excess air ratio in the combustion cylinder. Means and engine rotation To number Therefore, from the engine speed and the combustor inlet temperature when the backfire is detected by the backfire determination means, the backfire determination means for determining backfire from the temperature increase rate of the pre-evaporation premixing passage set to a predetermined value. Blow-off fuel flow rate based on a fuel injection amount determination map that calculates the blow-off fuel flow rate during operation In Predetermined value Added The fuel reduction means at the time of backfire for reducing the injection amount of the first fuel injection valve to the fuel flow rate, and the temperature of the pre-evaporation premixing passage become a predetermined value for the temperature of the pre-evaporation premixing passage before the backfire. Added The first fuel injection valve and the first fuel injection valve and the first fuel injection valve based on the fuel flow rate set by the flame extinguishing judgment means for judging that the backfire has extinguished when the temperature becomes lower, the normal fuel distribution setting means, or the fuel reduction means at the time of backfire. 2 fuel injection valve drive control means for driving and controlling the fuel injection valve In order to determine the flashback between pre-evaporation premixed combustion in which fuel is injected only from the first fuel injection valve and mixed mode combustion in which fuel is injected from the first fuel injection valve and the second fuel injection valve. Having a flashback determination means for changing the set value of the temperature change rate of the first temperature detection means It is set as the control apparatus of the combustor characterized by the above.
[0010]
The present invention also provides Pre-evaporation of the fuel injected from the first fuel injection valve disposed in the vicinity of the combustor inlet between the combustor inlet and the combustion cylinder into which the combustion air flows is introduced and mixed with the combustion air and led to the combustion cylinder. It has a premixing passage, a second fuel injection valve for diffusion combustion is provided at the connection between the prevaporization premixing passage and the combustion cylinder, and the required fuel injection amount set according to the operating state is set for normal fuel distribution According to the means, the first fuel injection valve and the second fuel injection valve are appropriately distributed and injected, and an intake for dilution air to be introduced into the combustion cylinder is opened in the combustion cylinder, and a predetermined excess air ratio is set in the combustion cylinder. In the combustor configured to combust, the first temperature detecting means for detecting the temperature of the pre-evaporation premixing passage, the second temperature detecting means for detecting the combustor inlet temperature, the first fuel injection valve, and the second fuel Set to a predetermined value according to the fuel injection rate from the injection valve. Backfire determination means for determining backfire from the temperature increase rate of the pre-evaporation premixing passage, and when backfire is detected by the backfire determination means, blow-off during operation from the engine speed and the combustor inlet temperature Based on a fuel injection amount determination map for calculating a fuel flow rate, a fuel reduction means at the time of backfire for reducing the injection amount of the first fuel injection valve to a fuel flow rate obtained by adding a predetermined value to the blown-off fuel flow rate, A flame extinguishing judgment means for judging that the backfire is extinguished when the temperature of the mixing passage is equal to or lower than a temperature obtained by adding a predetermined value to the temperature of the pre-evaporation premixing passage before the backfire, a normal fuel distribution setting means, Or a fuel injection valve drive control means for driving and controlling the first fuel injection valve and the second fuel injection valve based on the fuel flow rate set by the fuel reduction means at the time of flashback, For pre-evaporation determination in pre-evaporation premixed combustion in which fuel is injected only from the first fuel injection valve and in mixed mode combustion in which fuel is injected from the first fuel injection valve and the second fuel injection valve A combustor control device comprising a backfire determination means for changing a set value of the temperature change rate of the first temperature detection means. Combustor control device .
[0011]
Further, according to the present invention, in the control device for the combustor, fuel flow distribution between the first fuel injection valve and the second fuel injection valve is performed during mixed mode combustion in which fuel is injected from the first fuel injection valve and the second fuel injection valve. According to the present invention, there is provided a flashback determination means for changing the set value of the temperature change rate of the first temperature detection means for the flashback determination.
[0012]
Further, the present invention provides a flashback determination means for setting a set value of the temperature change rate of the first temperature detection means for flashback determination to become smaller as the engine speed increases in the control device of the combustor. It is characterized by having.
[0013]
Further, the present invention provides a control device for the combustor, in which the setting value of the temperature change rate of the first temperature detecting means for determining the backfire is set to be smaller in the mixed mode combustion than in the prevaporized premixed combustion. It has a fire determination means.
[0014]
Further, according to the present invention, in the control device for the combustor, the set value of the temperature change rate of the first temperature detecting means for the backfire determination at the time of mixed mode combustion is increased by the amount of fuel supplied from the second fuel injection valve. It is characterized by having a flashback determination means for setting a smaller value along with.
[0015]
Further, the present invention is characterized in that the control device for the combustor further includes a fuel reduction means at the time of flashback, wherein a predetermined value from a blow-off limit fuel flow rate is 0 to 0.5 g / s.
[0016]
Further, the present invention is characterized in that the control device for the combustor further includes a flame extinguishing judgment means that uses a temperature that assumes a value of 0 to 50 ° C. as a temperature of the pre-evaporation premixing passage before the backfire as a flame extinguishing judgment temperature. To do.
[0017]
In the combustor control apparatus according to the present invention, the first temperature detection means includes a backfire determination means using a thermocouple or a non-contact optical thermometer.
[0018]
Further, according to the present invention, the fuel injected from the first fuel injection valve disposed in the vicinity of the combustor inlet is evaporated between the combustor inlet and the combustion cylinder into which the combustion air flows and mixed with the combustion air for combustion. A required fuel injection amount that has a pre-evaporation premixing passage leading to a cylinder, includes a second fuel injection valve for diffusion combustion at a connection portion between the pre-evaporation premixing path and the combustion cylinder, and is set according to the operating state Is distributed to the first fuel injection valve and the second fuel injection valve as appropriate according to the normal fuel distribution setting means, and the intake of the dilution air to be introduced into the combustion cylinder is opened in the combustion cylinder. In a combustor configured to burn at a predetermined excess air ratio, first temperature detecting means for detecting the temperature of the pre-evaporation premixing passage, second temperature detecting means for detecting the combustor inlet temperature, and the vicinity of the combustor inlet The flame emission intensity of the pre-evaporation premixing passage When the flashback is detected by the flashback detection means, the flashback determination means for determining flashback from the rate of change of the flame emission intensity of the pre-evaporation premixing passage set to a predetermined value, and the flashback determination means Based on the fuel injection amount determination map that calculates the blow-off fuel flow rate during operation from the engine speed and the combustor inlet temperature, the injection amount of the first fuel injection valve is reduced from the blow-off fuel flow rate to the fuel flow rate that assumes a predetermined value. The backfire was extinguished when the temperature of the pre-evaporation premixing passage and the pre-evaporation premixing passage temperature to be equal to or less than the temperature expected for the pre-evaporation premixing passage before the flashback The fuel injection valve drive control controls the drive of the first fuel injection valve and the second fuel injection valve based on the fuel flow rate set by the flame extinguishing judgment means, the normal fuel distribution setting means, or the fuel reduction means during backfire. Means having A combustor controller according to.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a combustor control apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.
[0020]
FIG. 1 is a block diagram showing a configuration of a control device for a combustor according to the present invention.
As shown in FIG. 1, the control device for a combustor according to the present invention includes a first temperature detection means 101 for detecting the temperature of the pre-evaporation premixing passage, a second temperature detection means 102 for detecting the combustor inlet temperature, The backfire is determined from the temperature increase rate (ΔT / Δt) of the pre-evaporation premixing passage set to a predetermined value according to the engine speed or the fuel injection ratio from the first fuel injection valve 109 and the second fuel injection valve 110. Based on the backfire determination means 103 and the fuel injection amount determination map for calculating the blowout fuel flow rate during operation from the engine speed and the combustor inlet temperature when backfire is detected by the backfire determination means 103 The pre-evaporation pre-evaporation means 105 and the pre-evaporation premixing passage temperature for reducing the injection amount of the first fuel injection valve 109 from the fuel flow rate to the fuel flow rate that anticipates a predetermined value To the temperature of the mixing passage Based on the fuel flow rate set by the flame extinguishing judgment means 104 for judging that the backfire has extinguished when the temperature falls below a predetermined value, and the normal fuel distribution setting means 107 or the fuel reduction means 105 for backfire. The fuel injection valve drive control means 108 controls the drive of the first fuel injection valve 109 and the second fuel injection valve 110.
In the figure, reference numeral 106 denotes a required fuel injection amount setting means.
[0021]
(First embodiment)
FIG. 2 is a diagram showing a first embodiment of a control device for a combustor according to the present invention.
First, the configuration will be described with reference to FIG.
The combustor 1 provided with the intake passage serves as a pre-evaporation premixing passage surrounded by a cover 2 provided with an air introduction hole 2a for introducing combustion air supplied via a compressor and a heat exchanger (not shown). A pre-evaporation pipe 3 is provided, and a combustion cylinder 4 is connected to the downstream end of the pre-evaporation pipe 3.
[0022]
On the peripheral wall of the pre-evaporating tube 3 where the air introduction hole 3a is formed, an air flow rate adjusting ring-shaped sleeve 5 formed with an air introduction hole (not shown) is fitted freely. A first fuel injection valve 6 for pre-evaporation premixed combustion for injecting fuel into the pre-evaporation pipe 3 is attached to the upstream end of the pre-evaporation pipe 3, and is connected to the combustion cylinder 4. A second fuel injection valve 9 for diffusion combustion is provided at the downstream end of the evaporation pipe 3, which is attached to a flame holder 8 for holding a flame supported at the center of the pre-evaporation pipe 3 via a bracket 7. Yes.
[0023]
Furthermore, a first temperature sensor 10 is provided on the outer surface of the pre-evaporation tube 3 in the vicinity of the connection with the combustion cylinder 4 as first temperature detection means for detecting the temperature in the pre-evaporation tube 3. A second temperature sensor 31 as a second temperature detecting means for detecting the combustor inlet temperature is provided in the air introduction hole 2a for introducing the combustion air.
[0024]
The first temperature sensor 10 may be embedded in the wall surface of the pre-evaporation tube 3 instead of being attached to the outer surface of the pre-evaporation tube 3. Such an attachment structure has an advantage that the temperature change at the time of backfire can be captured more quickly and the backfire avoidance control can be performed at an early stage as compared with the structure attached to the outer surface of the pre-evaporation tube.
[0025]
A spark plug 11 is mounted on the combustion cylinder 4 with its tip facing the combustion cylinder 4. Further, on the peripheral wall of the combustion cylinder 4, a first air intake 4 a for introducing dilution air into the combustion cylinder 4 and a second air for introducing diffusion combustion air into the combustion cylinder 4. An intake 4b is formed. Then, similarly to the pre-evaporation pipe 3, the opening area of the first air intake 4a is varied to change the opening area of the ring-shaped first sleeve 12 for adjusting the intake air and the second air intake 4b. A ring-shaped second sleeve 13 for adjusting the intake air is rotatably fitted and attached. The sleeves 12 and 13 are integrally provided with gears 14 and 15, respectively.
[0026]
The gear 14 of the first sleeve 12 meshes with a gear 17 provided at the tip of a rotary shaft 16 rotatably supported on the outer wall of the combustor 1, and the gear 15 on the second sleeve 13 side is a rotary shaft 16. Is engaged with a gear 19 provided integrally with a cylindrical rotary shaft 18 that is rotatably fitted to and supported by the outer peripheral surface of the shaft.
[0027]
Connected to the base end portion of the rotating shaft 16 is a first actuator 22 that rotationally drives the rotating shaft 16 to rotate the first sleeve 12 so as to adjust the air taken in from the first air intake port 4a. Further, a second actuator 23 for rotating the second sleeve 13 is connected to the base end portion of the rotation shaft 18 so as to adjust the air taken in from the second air intake port 4b by driving the rotation shaft 18 to rotate. Yes.
[0028]
The control unit 20 that controls the combustion of the combustor 1 is constituted by a microcomputer, for example. In the normal state, the first fuel injection valve 6 and the second fuel injection valve 9, the first actuator 22, and the second actuator 23 are based on signals from the first temperature sensor 10 and the accelerator opening sensor 21 as in the conventional case. Is controlled to perform combustion in a predetermined lean state.
[0029]
That is, based on the pre-evaporation tube temperature Tp signal from the first temperature sensor 10, the normal fuel distribution map in which the allowable fuel injection amount from the first fuel injection valve 6 that can evaporate in the pre-evaporation tube 3 is set in advance is used. And an accelerator opening θ signal corresponding to the engine load from the accelerator opening sensor 21 is input to calculate the required fuel injection amount Gfset of the engine corresponding to the current operating state.
[0030]
Then, the fuel injection ratio from the first fuel injection valve 6 and the second fuel injection valve 9 with respect to the required fuel injection amount is calculated from the “engine speed-fuel injection amount” relationship diagram of the map 1 shown in FIG. Using the calculated value as an injection amount, fuel is injected from the first fuel injection valve 6 and the second fuel injection valve 9, and pre-evaporation premixed combustion and diffusion combustion are used in combination. Simultaneously with these fuel injection controls, the first sleeve 12, the first actuator 22 for driving the second sleeve 13, the second actuator according to the fuel injection amount assigned to the first fuel injection valve 6 and the second fuel injection valve 9. 23 is controlled so that the supply amount of combustion air and dilution air is appropriately controlled so that combustion in the combustion cylinder 4 is performed in a lean combustion state within a predetermined range.
[0031]
Further, as shown in the flow charts of FIGS. 3 and 4, the control unit 20 determines the occurrence of flashback in the pre-evaporation tube 3 based on the pre-evaporation tube temperature Tp of the first temperature sensor 10, and generates the backfire. When it is determined that the fuel supply amount from the first fuel injection valve 6 is reduced to near the blow-off limit at the time of operation, the fuel loss map at the time of backfire reduces the combustor inlet temperature Tin from the second temperature sensor 31 as a parameter. The fuel injection amount Gfp of the first fuel injection valve 6 is set to decrease from the engine speed N. Further, it is confirmed that the backfire is extinguished based on the pre-evaporation tube temperature Tp after the fuel is set to be reduced, and if the extinction is confirmed, the control is made to return to the normal fuel injection control.
[0032]
Here, the control unit 20 has functions of required fuel injection amount setting means, backfire determination means, backfire fuel reduction means, extinction determination means, normal fuel distribution setting means, and fuel injection valve drive control means. 3 and the flowchart of FIG. 4 are provided as software.
In FIG. 2, reference numeral 32 denotes an engine rotation sensor.
[0033]
Next, the backfire detection and the fuel injection amount control operation after the backfire detection by the combustor control device according to the first embodiment will be specifically described with reference to the flowcharts shown in FIGS. 3 and 4. .
[0034]
In step S1, the required fuel injection amount Gfset is read by a fuel flow meter (not shown).
In step S2, the engine speed N is read from the engine speed sensor 32 by a signal.
[0035]
In step S3, based on the map 1 shown in FIG. 5, the temperature increase rate upper limit (ΔTp / Δt) lim of the pre-evaporation premixing channel during operation is set from the required fuel injection amount Gfset.
In step S4, based on the signal from the first temperature sensor 10, the temperature Tp in the pre-evaporation tube 3 is determined. ₍₁₎ Is read.
[0036]
In step S5, the combustor inlet temperature Tin is read based on the signal from the second temperature sensor 31.
In step S6, the temperature increase rate (ΔTp / Δt) in the pre-evaporation tube 3 for a predetermined time Δt is calculated.
[0037]
In step S7, whether or not the temperature increase rate (ΔTp / Δt) in the pre-evaporation tube 3 calculated in step S6 is equal to or lower than the temperature increase rate upper limit (ΔTp / Δt) lim of the pre-evaporation premixing channel set in step S3. Determine.
If it is determined that “ΔTp / Δt ≦ (ΔTp / Δt) lim”, the process returns to step S1.
If it is determined that “ΔTp / Δt> (ΔTp / Δt) lim”, it is determined that backfire has occurred in the pre-evaporation tube 3, and the process proceeds to step S8.
[0038]
Steps S3, S6, and S7 correspond to the function of the backfire determination means (103 in FIG. 1).
[0039]
Here, a supplementary explanation will be given of the backfire determination means.
When it is attempted to determine backfire based on the temperature change ΔTp inside the pre-evaporation tube 3, ΔTp during backfire is fine depending on the engine speed N (or engine load), the pre-evaporation tube internal temperature Tp, and the combustor inlet temperature Tin. Since it fluctuates, it is difficult to accurately detect backfire. In this regard, when the rate of increase in the internal temperature of the pre-evaporation tube 3 (ΔTp / Δt) is used as a criterion, ΔTp / Δt during backfire is the engine speed N or the first fuel injection valve 6 and the second fuel injection valve. 9 is almost determined by the fuel injection distribution from the engine 9, so that the temperature increase rate in the pre-evaporation pipe 3 for the backfire determination is determined by the engine speed N or the fuel injection distribution from the first fuel injection valve 6 and the second fuel injection valve 9. If the upper limit (ΔTp / Δt) lim is set, backfire can be accurately determined.
[0040]
Here, the reason why the upper limit (ΔTp / Δt) lim of the temperature increase rate in the pre-evaporation tube 3 is changed by the engine speed N or the fuel injection distribution from the first fuel injection valve 6 and the second fuel injection valve 9 will be described. To do.
[0041]
In a combustor that uses both pre-evaporated premixed combustion and diffusion combustion used in a gas turbine engine or the like, as shown in FIG. 5, fuel is injected only from the first fuel injection valve 6 and burned by preevaporated premixed combustion alone. There are cases where fuel is injected from both the first fuel injection valve 6 and the second fuel injection valve 9 and pre-evaporation premixed combustion and diffusion combustion are simultaneously performed.
[0042]
When the operation is performed only by the pre-evaporation premixed combustion, the flame formed in the combustion cylinder 4 is a light blue flame that is almost colorless, and the radiation of heat from the flame to the surroundings is small. Therefore, the rate of increase (ΔTp / Δt) of the temperature in the pre-evaporation tube 3 when the flame is backfired from the combustion cylinder 4 to the pre-evaporation tube 3 is relatively large. At the time of pre-evaporation premixed combustion, there is a slight change in the rate of increase in the temperature in the pre-evaporation tube 3 (ΔTp / Δt). From the viewpoint of preventing malfunction of the backfire determination due to this change, The upper limit (ΔTp / Δt) lim of the temperature increase rate in the pre-evaporation tube 3 can be set higher as shown in FIG.
[0043]
Next, when pre-evaporation premixed combustion and diffusion combustion are performed simultaneously, the flame formed in the combustion cylinder 4 is brightened as the supply amount of the second fuel injection valve 9 increases and the rate of diffusion combustion increases. At the same time, the heat radiation from the flame to the surroundings increases. Therefore, the rate of increase in the pre-evaporation tube 3 temperature (ΔTp / Δt) when the flame is backfired from the combustion cylinder 4 to the pre-evaporation tube 3 decreases as the diffusion combustion rate increases. Alternatively, it is necessary to change the setting of the temperature rise rate upper limit (ΔTp / Δt) lim in the pre-evaporation pipe 3 in accordance with the fuel injection amounts from the first fuel injection valve 6 and the second fuel injection valve 9.
[0044]
As described above, the temperature increase rate (ΔTp / Δt) in the pre-evaporation tube 3 is detected, and it depends on the engine speed N or the fuel injection amount from the first fuel injection valve 6 and the second fuel injection valve 9. Thus, by changing the setting of the temperature rise rate upper limit (ΔTp / Δt) lim in the pre-evaporation tube 3, backfire can be detected with high accuracy only from the temperature in the pre-evaporation tube 3 under any operating conditions.
[0045]
In step S8, the pre-fire fuel loss map (map 2 in FIG. 6) set in advance is used, and the blown-off fuel flow rate (blown-off) during operation based on the signal from the engine rotation sensor 32 and the combustor inlet temperature Tin. Gfp) is set.
[0046]
In step S9, the fuel injection amount Gfp from the first fuel injection valve 6 is reduced to an amount obtained by adding the fuel flow rate ΔGfp by a predetermined value to the blow-off fuel flow rate (blow-off Gfp) set in step S8.
[0047]
Steps S8 and S9 correspond to the function of the fuel reducing means during backfire (105 in FIG. 1).
[0048]
In step S10, after the fuel is reduced, after waiting for the elapse of a predetermined time tw (backfire extinguishing and waiting time), the internal temperature Tp of the pre-evaporation tube 3 is again based on the signal from the first temperature sensor 10. ₍₂₎ Is read.
[0049]
In step S11, the pre-evaporation tube 3 internal temperature Tp read in step S10. ₍₂₎ However, the temperature Tp in the pre-evaporation tube 3 read in step S4 ₍₁₎ It is determined whether the temperature is equal to or lower than a temperature obtained by adding a temperature ΔT by a predetermined value.
“Tp ₍₂₎ ≦ Tp ₍₁₎ If it is determined that +? T ", it is determined that the backfire has extinguished, the process proceeds to step S16, Gfp is restored to the value before the backfire read in step S1, and the process returns to step S1.
“Tp ₍₂₎ > Tp ₍₁₎ When it is determined that + ΔT ″, it is determined that the backfire is not extinguished, and the process proceeds to step S12.
[0050]
In step S12, the fuel injection amount Gfp from the first fuel injection valve 6 is reduced to the blow-off fuel flow rate (blow-off Gfp) set in step S8.
In step S13, after the fuel is reduced, after waiting for the elapse of a predetermined time tw (backfire extinguishing and waiting time), the internal temperature Tp of the pre-evaporation tube 3 is again based on the signal from the first temperature sensor 10. ₍₃₎ Is read.
[0051]
In step S14, the pre-evaporation tube 3 internal temperature Tp read in step S13. ₍₃₎ However, the temperature Tp in the pre-evaporation tube 3 read in step S4 ₍₁₎ It is determined whether the temperature is equal to or lower than a temperature obtained by adding a temperature ΔT by a predetermined value.
“Tp ₍₃₎ ≦ Tp ₍₁₎ If it is determined that +? T ", it is determined that the backfire has extinguished, the process proceeds to step S16, Gfp is restored to the value before the backfire read in step S1, and the process returns to step S1.
“Tp ₍₃₎ > Tp ₍₁₎ If it is determined that + ΔT ″, it is determined that the backfire is not extinguished, and the process proceeds to step S15 to cut the fuel.
[0052]
Steps S10 to S14 correspond to the function of the flame extinguishing determination means (104 in FIG. 1).
[0053]
As described above, when a backfire occurs, it is possible to escape from the backfire at an early stage by restricting the fuel injection amount from the first fuel injection valve 6, thereby preventing a decrease in durability of the pre-evaporation pipe. be able to.
In addition, after the flashback occurs, the internal temperature of the pre-evaporation tube 3 is directly detected by a signal from the first temperature sensor 10 and the extinction is confirmed by confirming the extinction. The fall of property can be prevented.
[0061]
【The invention's effect】
As described above in detail, according to the present invention, the fuel injection amount from the first fuel injection valve is blown by the predetermined fuel control map when the flashback in the pre-evaporation premixing flow path is detected. It is configured to check the flame extinction from the temperature inside the pre-evaporation premixing flow path, and then check the flame extinction by detecting the occurrence of flashback at an early stage and confirming that the flame has been extinguished reliably. As a result, it is possible to prevent a decrease in durability of the pre-evaporation premixing channel and the like. As a result, the life of the combustor can be extended and the safety of engine operation can be improved.
[0062]
Fruit Each embodiment has the following effects in addition to the common effects. In the first embodiment, it is determined by the temperature increase rate (ΔTp / Δt) of the pre-evaporation premixing flow path and the engine speed N, or the fuel injection amounts from the first fuel injection valve and the second fuel injection valve. By determining the backfire from the upper limit value (ΔTp / Δt) lim of the temperature increase rate to be performed, the backfire can be determined only from the temperature of the pre-evaporation tube. Therefore, there is an effect that the configuration can be simplified and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a control device for a combustor according to the present invention.
FIG. 2 is a diagram showing a configuration of a pre-evaporation premix combustor showing the first embodiment.
FIG. 3 is a flowchart showing a control operation of the first embodiment.
FIG. 4 is a flowchart showing a control operation of the first embodiment.
FIG. 5 is a diagram (Map 1) for explaining the control operation of the first embodiment;
FIG. 6 is a diagram (Map 2) for explaining the control operation of the first embodiment;
[Figure 7 FIG. 1 is a diagram showing the configuration of a prior art pre-evaporation premix combustor.
[Explanation of symbols]
1 Combustor
2 Cover
2a Air introduction hole
3 Pre-evaporation tube
3a Air introduction hole
4 Combustion cylinder
4a First air intake
4b Second air intake
5 sleeve
6 First fuel injection valve
7 Bracket
8 Flame holder
9 Second fuel injection valve
10 First temperature sensor
11 Spark plug
12 First sleeve
13 Second sleeve
14, 15, 17, 19 Gear
16, 18 rotation axis
20 Control unit
21 Accelerator position sensor
22 First actuator
23 Second actuator
31 Second temperature sensor
32 Engine rotation sensor
101 First temperature detection means
102 2nd temperature detection means
103 Backfire determination means
104 Flame extinguishing judgment means
105 Fuel reduction means for flashback
106 Required fuel injection amount setting means
107 Normal fuel distribution setting means
108 Fuel injection valve drive control means
109 First fuel injection valve
110 Second fuel injection valve

Claims (9)

The fuel injected from the first fuel injection valve disposed in the vicinity of the combustor inlet is evaporated between the combustor inlet and the combustion cylinder into which the combustion air flows, and is mixed with the combustion air and led to the combustion cylinder. A pre-evaporation premixing passage is provided, and a second fuel injection valve for diffusion combustion is provided at a connecting portion between the preevaporation premixing passage and the combustion cylinder, and a required fuel injection amount set corresponding to an operating state is set. According to the normal fuel distribution setting means, the first fuel injection valve and the second fuel injection valve are appropriately distributed and injected, and the intake of the dilution air introduced into the combustion cylinder is opened in the combustion cylinder, In a combustor configured to burn with a predetermined excess air ratio in a combustion cylinder,
First temperature detecting means for detecting the temperature of the pre-evaporation premixing passage;
Second temperature detection means for detecting the combustor inlet temperature;
A flashback determining means for determining a flashback from the rate of temperature rise of the pre-vaporization Hatsu予mixing passage that is set to Therefore predetermined value of the engine speed,
Based on the fuel injection amount determination map that calculates the blown-off fuel flow rate during operation from the engine speed and the combustor inlet temperature when a back-fire is detected by the back-fire determination means, the blow-off fuel flow rate is set to a predetermined value. Fuel reduction means at the time of flashback for reducing the injection amount of the first fuel injection valve to the added fuel flow rate;
Flame extinguishing judgment means for judging that the backfire is extinguished when the temperature of the prevaporization premixing passage is equal to or lower than a temperature obtained by adding a predetermined value to the temperature of the prevaporization premixing passage before the backfire;
Fuel injection valve drive control means for driving and controlling the first fuel injection valve and the second fuel injection valve based on the fuel flow rate set by the normal fuel distribution setting means or the fuel reduction means at the time of flashback;
Have a,
The pre-evaporation premixed combustion in which fuel is injected only from the first fuel injection valve, and the mixed mode combustion in which fuel is injected from the first fuel injection valve and the second fuel injection valve, The flashback determination means for changing the set value of the temperature change rate of the first temperature detection means for
Combustor of the control device characterized by having a. The fuel injected from the first fuel injection valve disposed in the vicinity of the combustor inlet is evaporated between the combustor inlet and the combustion cylinder into which the combustion air flows, and is mixed with the combustion air and led to the combustion cylinder. A pre-evaporation premixing passage is provided, and a second fuel injection valve for diffusion combustion is provided at a connection portion between the preevaporation premixing passage and the combustion cylinder, and a required fuel injection amount set in accordance with an operating state is set. According to the normal fuel distribution setting means, the first fuel injection valve and the second fuel injection valve are appropriately distributed and injected, and an intake for dilution air to be introduced into the combustion cylinder is opened in the combustion cylinder, In a combustor configured to burn with a predetermined excess air ratio in a combustion cylinder,
  First temperature detecting means for detecting the temperature of the pre-evaporation premixing passage;
  Second temperature detection means for detecting the combustor inlet temperature;
  Backfire determination means for determining backfire from a temperature rise rate of the pre-evaporation premixing passage set to a predetermined value by a fuel injection ratio from the first fuel injection valve and the second fuel injection valve;
  Based on the fuel injection amount determination map that calculates the blown-off fuel flow rate during operation from the engine speed and the combustor inlet temperature when a back-fire is detected by the back-fire determination means, the blow-off fuel flow rate is set to a predetermined value. Fuel reduction means at the time of flashback for reducing the injection amount of the first fuel injection valve to the added fuel flow rate
  Flame extinguishing judgment means for judging that the backfire is extinguished when the temperature of the prevaporization premixing passage is equal to or lower than a temperature obtained by adding a predetermined value to the temperature of the prevaporization premixing passage before the backfire;
  Fuel injection valve drive control means for driving and controlling the first fuel injection valve and the second fuel injection valve based on the fuel flow rate set by the normal fuel distribution setting means or the fuel reduction means at the time of flashback;
  Have
  The pre-evaporation premixed combustion in which fuel is injected only from the first fuel injection valve, and the mixed mode combustion in which fuel is injected from the first fuel injection valve and the second fuel injection valve, The flashback determination means for changing the set value of the temperature change rate of the first temperature detection means for
  A combustor control apparatus comprising: The control device for a combustor according to claim 2,
During the mixed mode combustion in which fuel is injected from the first fuel injection valve and the second fuel injection valve, a backfire determination is made according to the fuel flow distribution of the first fuel injection valve and the second fuel injection valve. A combustor control apparatus comprising: a flashback determination unit that changes a set value of a temperature change rate of the first temperature detection unit. The control device for a combustor according to claim 1 or 2 ,
A combustor control apparatus comprising: a backfire determination means for setting a set value of a temperature change rate of the first temperature detection means for backfire determination to be smaller as the engine speed increases. The control device for a combustor according to claim 1 or 2,
Combustor comprising backfire determination means for setting a set value of the temperature change rate of the first temperature detection means for backfire determination to be smaller at the time of mixed mode combustion than at the time of pre-evaporation premixed combustion. Control device. The control device for a combustor according to claim 5,
Backfire determination means for setting a set value of the temperature change rate of the first temperature detection means for determining backfire during mixed mode combustion to be smaller as the fuel supply amount from the second fuel injection valve increases. A control device for a combustor, comprising: The control device for a combustor according to claim 1 or 2 ,
A control device for a combustor, comprising: a fuel reduction means at the time of flashback, wherein a predetermined value from a blow-off limit fuel flow rate is 0 to 0.5 g / s. The control device for a combustor according to claim 1 or 2 ,
A combustor control apparatus, comprising: a flame extinguishing determination unit that uses, as a flame extinguishing determination temperature, a temperature in which a value of 0 to 50 ° C. is estimated as a temperature of a pre-evaporation premixing passage before flashback. The control device for a combustor according to claim 1 or 2 ,
A combustor control apparatus comprising: a backfire determination means using a thermocouple or a non-contact optical thermometer as the first temperature detection means.

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