JP2008057417A - Gas turbine equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide gas turbine equipment that eliminates the need for special operation and a power source for inserting and pulling off an ignition plug. <P>SOLUTION: The equipment includes a compressor 2 for compressing air, a combustor 4 for burning compressed air and fuel, a turbine 1 driven by combustion gas generated in the combustor, and a regeneration heat exchanger 5 for exchanging heat between exhaust gas of the turbine and compressed air introduced to the combustor. The ignition plug of the combustor is constructed in such a manner that the same can be inserted in a combustor liner and can be pulled out to an outside by using delivery air of the compressor. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of igniting a combustor applied to a regeneration cycle gas turbine facility, and more particularly to a mechanism of a spark plug device.

  As an example of applying a regeneration cycle to a gas turbine having a relatively small output, there is a micro turbine described in Japanese Patent Application Laid-Open No. 2001-12256. This technique is characterized by a relatively simple structure in which a generator rotor, a compressor impeller, and a turbine wheel are incorporated in a common rotating shaft. In such a gas turbine, it is important to simplify the structure of the combustor installed in the system. In particular, the structure of the spark plug device is avoided to be a complicated movable type, and a fixed spark plug is incorporated. There are many.

  On the other hand, in the regeneration cycle, the air pressurized by the compressor is heated by heat exchange with the turbine exhaust in the regeneration heat exchanger, so the air sent to the combustor is already at a high temperature of 600 ° C. or higher. For this reason, less fuel is required to raise the temperature to the specified combustion temperature, which contributes to the improvement of power generation efficiency. However, since it is a small amount of fuel, it burns immediately upon dropping the fuel and tends to cause high temperature combustion locally. High temperature combustion tends to generate NOx, which is not preferable for a turbine system. As a combustor for improving such a situation and combusting a small amount of fuel efficiently, for example, there is a slow combustion low NOx combustor described in International Publication WO2005 / 059442A1. In the slow combustion method, a fuel and air injection flow for the pilot burner, and an air flow in a direction perpendicular to the pilot burner injection flow in the downstream region of the injection flow are used to generate a large-scale circulation flow of fuel and air. It is characteristic to form a region. If ignition is performed by inserting an ignition plug into the circulation flow region of fuel and air injected from the pilot burner, reliable ignition can be performed and ignition failure and misfire can be avoided.

JP 2001-12256 A WO 2005/059442 A1

  However, since the circulating flow region described above becomes high temperature after ignition, it is not preferable to fix the spark plug in this region during turbine operation, and it is necessary to draw out the spark plug from the combustor after ignition. Although it is necessary to make a movable structure for inserting and extracting the spark plug, it is desirable that the structure does not require a special operation or a driving source for inserting and extracting the spark plug.

  An object of the present invention is to provide a gas turbine facility that does not require a special operation or a driving source for inserting and extracting a spark plug.

  In order to achieve the above object, the gas turbine equipment of the present invention is characterized in that the ignition plug of the combustor is configured to be inserted into the combustor liner and drawn out to the outside using the discharge air of the compressor. Is.

  According to the present invention, since the ignition plug can be automatically inserted into and extracted from the combustor liner by increasing the discharge pressure of the compressor, the operation and the drive source for inserting and extracting the ignition plug can be eliminated. There is.

  A micro gas turbine power generation facility according to an embodiment of the present invention will be described with reference to FIG.

  FIG. 1 is a diagram showing an outline of a micro-turbine system to which a regeneration cycle is applied. The system mainly includes a turbine 1, a compressor 2, a generator 3, a combustor 4, and a regenerative heat exchanger 5. The generator 3 is a permanent magnet three-phase generator using a permanent magnet for generating a field, and a permanent magnet is attached to the generator rotor 47. A stator coil 48 is installed so as to surround the rotor. The compressor 2 and the turbine 1 are attached to the drive shaft 6 of the generator rotor 47 at the extended end of the same shaft. The generator 3 is connected to a power converter (not shown). The power converter includes a converter that converts alternating current power into direct current and an inverter that converts the direct current into alternating current power that matches the commercial frequency.

  At the start of operation of the turbine system, electricity is drawn from the system side (not shown) and supplied to the generator to operate the generator 3 as an electric motor. As the drive shaft 6 rotates, the compressor 2 and the turbine 1 rotate. The compressor 2 sucks outside air through the filter 7 and the silencer 8, increases the pressure, sends it to the regenerative heat exchanger 5 through the compressor discharge pipe 10, and sends the compressor 2 to the combustor 4 through the regenerative heat exchanger air side outlet pipe 11. Supply discharge air from As the rotational speed of the rotor 6 increases, the discharge air pressure of the compressor 2 rises, and when it reaches a specified rotational speed or discharge pressure at which the amount of air required for ignition of the combustor 4 is reached, the fuel supply line 12 The installed shut-off valve 14 is opened, and the specified fuel is supplied by the fuel flow rate adjusting valve 13, and the fuel is mixed with the discharge air from the compressor 2 and burned. The combustion gas performs expansion work in the turbine 1, passes through the regenerative heat exchanger 5, and is discharged outside the turbine system through the exhaust duct 15. In the regenerative heat exchanger 5, the exhaust gas from the turbine heats the compressor discharge air sent through the compressor discharge pipe 10. When power generation is started by the generator 3 due to an increase in expansion work of the combustion gas in the turbine 1, a power converter (not shown) converts the generated power into the frequency of the system power (commercial frequency) and outputs it.

  Here, in the illustrated embodiment, an air cylinder 17 is attached to the combustor 4, and a spark plug rod 16 is installed inside the air cylinder. The air cylinder 17 is connected to the compressor discharge pipe 10 by a spark plug working air introduction pipe 18 so that the compressor discharge pressure acts in the air cylinder. The operation of the spark plug and the ignition method of the combustor will be described later with reference to FIG.

  As a combustor that efficiently burns a small amount of fuel, for example, there is a slow combustion type low NOx combustor disclosed in International Publication WO2005 / 059442A1. FIG. 2 shows a longitudinal sectional view thereof.

  The combustor is roughly divided into a pilot burner 31, a combustor liner 32, a combustor end cover 33, and a combustor outer cylinder 34. The pilot burner 31 is a burner responsible for ignition related to the start-up of the gas turbine power generation facility, and a swirl passage 46 having swirl vanes 41 is provided around the primary fuel nozzle 43 to introduce primary air into the swirl passage 46. There are eight holes 42 in the circumferential direction. The combustor liner 32 is a component that constitutes a combustion chamber, and dilution holes 52 provided at six locations in the circumferential direction and secondary air provided at three locations in the circumferential direction for smoothing the temperature distribution of the combustor outlet gas. It has an introduction hole 53 and is connected to a transition piece that is a communication part with a turbine (not shown).

  Combustion air 56 flows in from the space with the combustor outer cylinder 34 outside the combustor liner 32, dilution holes 52 provided at six locations in the circumferential direction, and secondary air introduction holes 53 provided at three locations in the circumferential direction. From the primary air introduction holes 42 provided at eight locations in the circumferential direction to the swirl passage 46 and given swirl by the swirl vanes 41, and then flow inside the combustor liner 32, It flows out to a transition piece, which is a communication part with a turbine (not shown).

  Fuel is independently supplied to the primary fuel nozzle 43 and the secondary fuel nozzle 49 in the center of the drawing, and is ejected from the primary fuel injection hole 44 and the secondary fuel injection hole 57 into the combustion chamber. All fuel is injected directly into the combustion chamber, and there is no part such as a premixer in which fuel and air are mixed outside the combustion chamber.

  The pilot burner 31 employs a normal diffusion combustion method. In the gas turbine power generation facility, when the air flow rate can be sufficiently ensured except for ignition, the primary combustion flows into the turning passage 46 from the primary air introduction hole 42 and is given a predetermined turning by the turning blade 41. Since the working air 50 enters the combustion chamber from the outlet of the swirl passage 46 and rapidly expands, a circulation flow region is formed downstream of the primary fuel nozzle 43 at the head of the combustor. Fuel is injected from the primary fuel injection hole 44 opened at the end face of the primary fuel nozzle 43 into the circulation flow region, and diffusion combustion is performed.

  On the other hand, in the secondary air 51 ejected from the secondary air introduction hole 53 into the combustion chamber, fuel is radially injected from the secondary fuel nozzle 49 installed at the same position as the secondary air introduction hole 53. . However, immediately after the secondary fuel injection, the flow rate of the secondary air 51 entering the combustion chamber is high, and the shearing with the surrounding combustion gas is strong, so the flame blows off immediately after the combustion reaction starts. Since the flame is not held in the vicinity of the secondary fuel nozzle 49, a local high temperature region does not appear in the vicinity of the wall of the secondary fuel nozzle 49 or the combustor liner 32, which is advantageous from the viewpoint of ensuring reliability.

  When this gas turbine combustor is ignited, the primary combustion air 50 flows into the swirl passage 46 from the primary air introduction hole 42, is given a predetermined swirl by the swirl vanes 41, and burns from the outlet of the swirl passage 46. Although entering the chamber and expanding rapidly, the flow velocity is slow, so that the circulation flow region is not formed downstream of the primary fuel nozzle 43 in the head of the combustor, and the inside of the combustor liner 32 is directed downstream. The primary combustion air 50 heading downstream is generated in the vicinity of the central axis of the combustor liner 32 and the secondary air 51 ejected into the combustor liner 32 from the secondary air introduction holes 53 in three circumferential directions. They collide with each other to form an inward flow circulation flow 55 and form a stagnation region. In this stagnation region, since the flow velocity is reduced and the propagation flame can be sufficiently maintained, the primary fuel 54 introduced into the primary combustion air 50 is in the circulating flow 55 of the inward flow. The combustion reaction begins and ignition occurs.

  An air cylinder 17 is attached to the combustor outer cylinder 34, and the spark plug rod 16 can be inserted into or extracted from the combustor liner through a through hole provided in the combustor outer cylinder seal portion 23 and the combustor liner penetration portion 24. The combustor outer cylinder seal portion 23 prevents air leakage from the inside of the combustor outer cylinder into the air cylinder, or conversely, from the air cylinder to the combustor outer cylinder. A spark plug bottom plate 22 is attached to the spark plug rod 16, and a spring 20 is fixed on the side opposite to the tip of the spark plug rod. In addition, an ignition electric wire 19 for supplying electricity for generating an ignition spark is drawn out of the air cylinder through the spring 20. The spark plug rod is sealed so that combustion gas does not leak from the tip of the spark plug into the air cylinder. Of the two regions of the air cylinder 17 partitioned by the spark plug bottom plate 22, a spark plug working air introduction pipe 18 is connected to a region where the spring 20 is not installed, and this ignition line working air introduction pipe 18 is not shown. It is connected to the compressor discharge pipe 10. Further, an air vent hole 58 that communicates with the outside air is formed in the end surface of the case in a region where the spring 20 is installed.

  The spark plug position shown in FIG. 2 indicates a state in which the turbine system is stopped or a state at the ignition rotation speed. The rotational speed is smaller than the rated rotational speed, and the discharge pressure of the compressor is not sufficiently increased. In this state, the spring force of the spring 20 exceeds the force pushing the spark plug bottom plate 22 by the compressor discharge pressure, and the tip of the spark plug rod 16 is pushed out to the center inside the combustor liner. When the turbine system is activated and reaches the ignition speed, the tip of the spark plug rod is located inside the combustor liner as described above, inside the circulation vortex of the inward circulation flow formed by the fuel and air ejected from the pilot burner. Is located and can be easily ignited.

  FIG. 3 shows a spark plug rod 16 in a state where the rotational speed of the turbine system is increased and the compressor discharge pressure is sufficiently increased to overcome the spring force of the spring 20 installed in the air cylinder or the rated rotational speed is reached. The position state of is shown. The force acting on the spark plug bottom plate 22 by the air pressure guided from the spark plug working air introduction pipe 18 becomes larger than the force pressing the spark plug bottom plate 22 by the spring 20, and the spark plug rod 16 is pulled out from the combustor liner. During the rated operation of the turbine system, the compressor discharge pressure increased by the ignition plug working air introduction pipe 18 is guided into the air cylinder, so that the state where the ceiling plug is pulled out from the combustor liner can be maintained.

  At the time of stop, contrary to the start-up, at the stage where the fuel supply is stopped to stop the combustion and the rotational speed is lowered, the spark plug bottom plate 22 is acted on by the air pressure guided from the spark plug working air introduction pipe 18. When the force becomes smaller than the force pressing the spark plug bottom plate 22 by the spring 20, the spark plug rod moves again to the combustor liner. When the turbine system is completely stopped, it can return to the position shown in FIG. 2 again to prepare for the next ignition.

  In the embodiment of FIGS. 2 and 3, the timing of insertion and withdrawal of the spark plug from the combustor liner can be adjusted by adjusting the spring force. Considering that the turbine system is operated at a partial load, adjustment is made so as to overcome the spring force and push up the spark plug bottom plate 22 even at the compressor discharge pressure in a 50% load state. Further, in FIG. 3, when the spark plug is pulled out, the tip position of the spark plug rod is near the outside of the wall surface of the combustor liner. You may protect yourself from exposure to hot air.

  In the above-described embodiment, an ignition plug is inserted into the circulation flow formed by the fuel and air injection from the pilot burner of the slow combustion type low NOx combustor during ignition, and after ignition, the ignition plug is inserted from the inside of the combustor. Pull out. This operation of insertion and withdrawal is performed by avoiding complicated control and using spring force and compressor discharge pressure, so that it automatically operates as the operating speed of the turbine increases and decreases. It is a thing.

  According to the present embodiment, the insertion and withdrawal of the ignition plug into the combustor liner can be automatically performed by increasing the compressor discharge pressure, so that an operation and a drive source for insertion and extraction of the ignition plug rod are not necessary, There is an effect that turbine operation control can be simplified. Further, at the time of ignition, since the tip of the spark plug rod is inserted into a circulating vortex formed by fuel and air ejected from the pilot burner, there is an effect that reliable ignition can be performed. Further, during operation of the turbine, since the spark plug rod is pulled out from the combustor liner, it does not come into direct contact with the high-temperature gas, and there is an effect that it is possible to prevent the life of the spark plug rod from being reduced due to heat.

  Further, since the air introduced into the air cylinder 21 is not the combustion air heated through the regenerative heat exchanger but the compressor discharge air, the deformation of the spark plug rod due to heat, The effect of heat such as deformation of the air cylinder can be reduced.

  FIG. 4 shows another embodiment of the present invention. In FIG. 4, an ignition plug insertion air pipe 26 and an ignition plug return air pipe 25 are installed in two chambers partitioned by the air cylinder 17 by the spark plug bottom plate 22, respectively. The service air pipe 25 is connected to the spark plug working air introduction pipe 18. Each pipe is provided with three-way valves 28 and 27 for connecting the spark plug working air introduction pipe 18 and the air cylinder or switching the air cylinder and the atmosphere open. Until the turbine stops or before ignition, the three-way valve 28 connects the spark plug working air introduction pipe 18 and the air cylinder, and the three-way valve 27 keeps the atmosphere open and the air cylinder in conduction. During operation of the turbine from the compressor, the discharge pressure of the compressor is higher than that of the atmosphere, so the spark plug rod remains inserted in the combustor liner. After ignition, the three-way valve is switched, the three-way valve 27 connects the spark plug working air introduction pipe 18 and the air cylinder, and the three-way valve 28 keeps the atmosphere open and the air cylinder conductive. As the discharge pressure of the compressor increases, the spark plug rod is pushed back and withdrawn from the combustor liner. When stopping, the three-way valves 28 and 27 are switched when the fuel is shut off, and the spark plug rod is moved at the next ignition by moving the spark plug rod while the discharge pressure from the compressor is high. Be positioned in the center of the combustor liner.

  According to this embodiment, the insertion and withdrawal of the spark plug rod into the combustor liner can be automatically performed by increasing the compressor discharge pressure by simply switching the three-way valve. There is an effect that a driving source becomes unnecessary and turbine operation control can be simplified. Further, at the time of ignition, since the tip of the spark plug rod is inserted into a circulating vortex formed by fuel and air ejected from the pilot burner, there is an effect that reliable ignition can be performed. Further, during operation of the turbine, since the spark plug rod is pulled out from the combustor liner, it does not come into direct contact with the high-temperature gas, and there is an effect that it is possible to prevent the life of the spark plug rod from being reduced due to heat. Furthermore, since the air introduced into the air cylinder 21 is compressor discharge air, it is not combustion air whose temperature has been raised through the regenerative heat exchanger, so deformation of the spark plug rod due to heat, The effect of heat such as deformation of the air cylinder can be reduced.

  FIG. 5 is a view showing another embodiment of the present invention. In FIG. 5, water is sprayed onto the turbine system to further improve the power generation efficiency of the turbine. A spray water nozzle 37 is attached to the compressor discharge pipe 10, and water pressurized by the spray water pump 35 from the spray water tank 36 is sprayed to the compressor discharge air through the spray water duct 29 provided with the spray water shut-off valve 30. The efficiency of heat recovery from the turbine exhaust gas in the regenerative heat exchanger 5 is improved by the decrease in the air temperature due to the cooling effect of the spray water, and the turbine output and efficiency are both improved due to the mass increase effect by the water spray. improves.

  Here, the discharge air of the compressor contains water or water vapor by water spray. When this air enters the air cylinder, water accumulates in the case and hinders the movement of the spark plug rod. For this reason, the ignition plug working air introduction pipe 18 is connected to the compressor discharge pipe 10 at the upstream side of the spray water nozzle 37, and the spark plug working air introduction pipe 18 is further provided with a spark plug drain pipe 38. Further, a spray water drain pipe 39 is also installed in the compressor discharge pipe 10 on the downstream side of the spray water nozzle 37. The drain collected by the spark plug drain pipe 38 merges with the collected drain of the spray water drain pipe 39 and is led to the drain outlet 45 outside the system through the drain trap 40. The drain trap 40 is closed to the atmosphere side until the drain reaches the specified water amount, and when the specified water amount is reached, the valve is opened to discharge the drain to the atmosphere. The spark plug drain pipe 38 is provided with a U-shaped portion 59 so that the pressure in the air cylinder does not drop rapidly when the drain trap 40 is opened to the atmosphere.

  In the present embodiment, even when the turbine output and efficiency are increased by water spraying, there is an effect that it is possible to prevent water from entering the air cylinder and to avoid an operation trouble of the spark plug rod.

  1 and 5, the regeneration cycle gas turbine system is illustrated, but it goes without saying that the above-described combustor may be applied to a simple cycle or other cycles.

The figure which shows the outline | summary of the regeneration cycle gas turbine system which is one Example of this invention. FIG. 2 is an enlarged view of the combustor shown in FIG. 1 and shows a state where the turbine system is stopped or in an ignition rotation speed. FIG. 2 is an enlarged view of the combustor shown in FIG. 1, showing a state in which the compressor discharge pressure exceeds the spring force or reaches a rated rotational speed. The figure which shows the other structural example of a combustor. The figure which shows the outline | summary of the regeneration cycle gas turbine system which is the other Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Turbine, 2 ... Compressor, 3 ... Generator, 4 ... Combustor, 5 ... Regenerative heat exchanger, 6 ... Rotating shaft, 7 ... Intake filter, 8 ... Intake silencer, 9: ... Intake duct, 10 ... Compression Machine discharge pipe, 11 ... Regenerative heat exchanger air side outlet pipe, 12 ... Fuel supply line, 13 ... Flow rate adjustment valve, 14 ... Shut-off valve, 15 ... Exhaust duct, 16 ... Spark plug rod, 17 ... Air cylinder, 18 ... ignition plug working air introduction pipe, 19 ... electrical wiring for ignition, 20 ... spring, 21 ... high-pressure air chamber, 22 ... spark plug bottom plate, 23 ... combustor outer cylinder seal part, 24 ... combustor liner penetration part, 25 ... Spark plug return air piping, 26 ... Spark plug insertion air piping, 27, 28 ... 3-way valve, 29 ... Spray water duct, 30 ... Spray water shut-off valve, 31 ... Pilot burner, 32 ... Combustor liner, 33 ... Combustor end cover, 34 ... Combustor outer cylinder 35 ... Spray water pump, 36 ... Spray water tank, 37: Spray water nozzle, 38 ... Spark plug drain piping, 39 ... Spray water drain piping, 40 ... Drain separator, 41 ... Swivel blade, 42 ... Primary air introduction Holes, 43 ... primary fuel nozzle, 44 ... primary fuel injection hole, 45 ... drainage port, 46 ... swirl passage, 47 ... generator rotor, 48 ... stator coil, 49 ... secondary fuel nozzle, 50 ... primary combustion air, 51 ... secondary air, 52 ... dilution hole, 53 ... secondary air introduction hole, 54 ... primary fuel, 55 ... circulating flow of inward flow, 56 ... combustion air 57 ... Secondary fuel injection holes, 58 ... Air vent holes, 59 ... U-shaped part.

Claims (10)

A compressor for compressing air;
A combustor for burning compressed air and fuel;
A turbine driven by combustion gas generated in the combustor;
In a gas turbine facility comprising a regenerative heat exchanger for exchanging heat between exhaust gas of the turbine and compressed air introduced to the combustor,
The gas turbine equipment, wherein the ignition plug of the combustor is configured to be inserted into the combustor liner and drawn out to the outside using the discharge air of the compressor. The combustor
An ignition plug rod is disposed at the tip of the long shaft rod, and a bottom plate is installed on the opposite rod end to receive the air pressure of the compressor discharge air and generate a force to move the long shaft rod;
The gas turbine equipment according to claim 1, further comprising an air cylinder including the spark plug rod and attached to an outer wall of the combustor. The combustor
A spring installed in one region in the air cylinder divided into two by the bottom plate;
The gas turbine equipment according to claim 2, further comprising a spark plug working air introduction pipe for introducing compressor discharge air into the other region in the air cylinder.   4. The gas turbine equipment according to claim 3, wherein the combustor is configured so that the spark plug is inserted into the combustor by the spring, and the spark plug is pulled out from the combustor by the compressor discharge air. . The combustor
A spark plug insertion air pipe for introducing compressor discharge air that applies a force to insert the spark plug into the combustor into one region in the air cylinder divided into two by the bottom plate;
3. The spark plug return air pipe for introducing compressor discharge air for applying a force for pulling out the spark plug from the combustor to the other region in the air cylinder. Gas turbine equipment.   6. The gas according to claim 5, wherein the spark plug insertion air pipe and the spark plug return air pipe introduce compressor discharge air through a three-way valve communicating with the atmosphere by switching the valve. Turbine equipment. The combustor includes a combustor liner, a combustor end cover, a combustor outer cylinder, a pilot burner that ejects fuel and air into the combustor liner from the combustor end cover side in the axial direction of the combustor liner, A combustor in which a secondary fuel nozzle that ejects fuel from the side surface of the combustor liner toward the center of the combustor liner axis is disposed downstream of the pilot burner,
The secondary fuel nozzle is located downstream of the pilot bar bar at the insertion position of the spark plug inserted from the outside toward the center of the combustor liner shaft through a through hole provided on the side surface of the combustor outer cylinder and the combustor liner. The gas turbine equipment according to claim 1, wherein the gas turbine equipment is installed at a location located on the upstream side. The gas turbine equipment is
A spray water nozzle for spraying water on the compressor discharge air is provided in the middle of the path for guiding the compressor discharge air from the compressor to the regenerative heat exchanger, and the drain in the compressor discharge air for operating the spark plug is used as a system. The gas turbine equipment according to claim 1, wherein a drain pipe for discharging outside is installed. The gas turbine equipment is
A spray water nozzle for spraying water on the compressor discharge air is provided in the middle of a path for leading the compressor discharge air from the compressor to the regenerative heat exchanger, and the spray water is used as the compressor discharge air for operating the spark plug. The gas turbine equipment according to claim 1, wherein the compressor discharge air upstream of the nozzle is used. In a combustor comprising a combustor liner that forms a combustion chamber therein, a combustor outer cylinder containing the combustor liner, and a spark plug,
A combustor characterized in that the spark plug can be inserted into the combustor liner and pulled out to the outside using compressor discharge air.

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