Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
  • F02C7/00—Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
  • F02C7/12—Cooling of plants
  • F02C7/16—Cooling of plants characterised by cooling medium
  • F02C7/18—Cooling of plants characterised by cooling medium the medium being gaseous, e.g. air
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
  • F02C7/00—Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
  • F02C7/22—Fuel supply systems
  • F02C7/224—Heating fuel before feeding to the burner
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
  • F02C7/00—Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for jet-propulsion plants
  • F02C7/12—Cooling of plants
  • F02C7/16—Cooling of plants characterised by cooling medium
  • F02C7/18—Cooling of plants characterised by cooling medium the medium being gaseous, e.g. air
  • F02C7/185—Cooling means for reducing the temperature of the cooling air or gas

Definitions

• Cooling system for cooling cooling air of a gas turbine and method for cooling cooling air are provided.
• the invention relates to a cooling system for recooling cooling air branched off from the compressor air of a gas turbine. It also relates to a method for cooling the cooling air.
• the heat contained in the expanded working fluid (flue gas) from the gas turbine is used to generate steam for the steam turbine.
• the heat transfer takes place in a heat recovery steam generator downstream of the flue gas side, in which heating surfaces are arranged in the form of tubes or tube bundles. These in turn are connected to the steam turbine water-steam cycle.
• the steam generated in the waste heat steam generator is fed to the steam turbine, where it relaxes while performing work.
• the steam expanded in the steam turbine is usually fed to a condenser and condenses there.
• the condensate formed during the condensation of the steam is fed back into the waste heat steam generator as feed water, so that a closed water-steam cycle is created.
• auxiliary steam generator also known as a kettle boiler
• the air serving as coolant is cooled before entering the gas turbine.
• An auxiliary steam generator also known as a kettle boiler, is usually used in the gas and steam operation of the system, which absorbs the heat removed from the compressor air and uses it, for example, to evaporate water.
• the resulting steam is fed into the steam cycle.
• a comparatively large air cooler also referred to as a fin fan cooler, is therefore usually used as an alternative for recooling the cooling air.
• Switching from pure gas turbine to gas and steam turbine operation therefore also requires a U - switch between the cooling systems for the cooling air.
• a load reduction or even a load shutdown of the system when switching from pure gas turbine to gas and steam operation may be unavoidable.
• the invention is therefore based on the object of specifying a cooling system for a gas and steam turbine system which is suitable for dissipating heat from the cooling air and which can be flexibly adjusted to the operating state of the gas and steam turbine with a low outlay on equipment.
• suitable method for cooling the cooling air would be specified for different operating conditions of the application.
• this object is achieved according to the invention in that a heat exchanger system, which is connected on the primary side to a cooling air line branching off the compressor air line, transfers heat carried along in the cooling air to the fuel gas flow supplied to the combustion chamber of the gas turbine.
• the invention is based on the consideration that in a cooling system which can be flexibly adapted to the operating state of the gas and steam turbine system, reliable cooling of the cooling air should be ensured independently of any heat input into the water-steam circuit of the steam turbine.
• the cooling system of the cooling air when it is recooled should transfer heat extracted to a medium that is available in every operating state of the system.
• a medium that is particularly suitable for this purpose, when the heat is coupled into the actual energy generation process and thus also a particular gain in efficiency can be achieved, is the fuel gas flow supplied to the combustion chamber.
• the amount of heat extracted from the cooling air flow for reliable recooling of the cooling air is generally greater than that required for preheating the fuel gas, in other words with the usual dimensions of gas and steam turbine systems. Therefore, the amount of heat supplied to the fuel gas stream is advantageously adjustable. This ensures that there is always a sufficient amount of heat available to preheat the fuel gas and that the remaining amount of heat is dissipated in a different way.
• the possibility of dissipating the heat from the cooling air which can be flexibly adjusted to the operating state of the system, is achieved by dividing the heat flow discharged from the cooling air into partial flows, one of which is supplied to the fuel gas flow and another is used, for example, to produce steam which can be supplied by the steam turbine becomes.
• the division into sub-streams takes into account the condition that the sub-stream supplied to the fuel gas stream carries with it exactly the amount of heat required for preheating the fuel gas, while the further sub-stream (s) dissipate the heat not required for preheating the fuel gas or otherwise, for example for Generation of auxiliary steam.
• the heat flow can be divided by the parallel connection of a number of intermediate circuits on the heat flow side. This results in possibilities for dissipating heat in each intermediate circuit, and the cooling system can be used particularly flexibly.
• the heat exchanger system can comprise a heat exchanger which is connected directly to the fuel gas stream on the secondary side and which transfers heat from the cooling air stream to the fuel gas stream.
• the heat is expediently transferred via at least one intermediate circuit via which a boiler boiler is also referred to Auxiliary steam generator is connected on the secondary side to a heat exchanger, the latter being connected on the secondary side to the fuel gas stream.
• a boiler boiler is also referred to
• Auxiliary steam generator is connected on the secondary side to a heat exchanger, the latter being connected on the secondary side to the fuel gas stream.
• a further auxiliary steam generator can also be connected in the intermediate circuit, which uses the heat to be removed to generate auxiliary steam required in the system.
• the heat-side connection of the heat exchanger system to the further heat exchanger can be implemented via the auxiliary steam generator, and the intermediate circuit can thus have two stages.
• the intermediate circuit can thus have two stages.
• the object is achieved in that heat extracted from the cooling air stream is transferred to the fuel gas stream supplied to the combustion chamber of the gas turbine.
• the amount of heat supplied to the fuel gas stream is advantageously adapted to the operating state of the gas turbine system.
• the cooling air flow branched off from the compressor air is advantageously divided into a number of partial flows, one of which feeds the amount of heat required for preheating the fuel gas to the fuel gas flow.
• the amount of heat provided for preheating the fuel gas is expediently transferred via a heat exchanger connected directly into the fuel gas stream on the secondary side.
• a single or even two-stage intermediate circuit can be provided. This is particularly useful if components already present in the cooling system components such as heat exchangers or auxiliary steam generators should be used.
• an intermediate circuit enables a more flexible division of the heat flow into partial flows and a more flexible interconnection of already existing components.
• an auxiliary steam generator is expediently switched into one of the partial flows not supplied to the fuel gas flow.
• This auxiliary steam generator uses the excess heat as evaporative heat to generate the auxiliary steam required in the system and thus contributes to increasing the efficiency of the system.
• the advantages achieved by the invention are in particular that by transferring at least part of the heat extracted from the cooling gas stream to the fuel gas stream, an increase in the efficiency of the gas and steam turbine system in pure gas turbine operation is achieved by saving external preheating sources. Since, in addition, regardless of the operating state of the steam turbine, a significant portion of the heat extracted from the cooling air during recooling can be reliably dissipated via the fuel gas flow, a switch from pure gas turbine operation to gas and steam operation is possible without the previously unavoidable load reduction or load shutdown allows. In addition, various components that take up a lot of space, such as external heating gas preheaters and the comparatively large air cooler, also known as fin fan cooler, can be saved.
• FIG. 1 schematically shows a cooling system for cooling cooling air for a gas turbine
• FIG. 2 shows a cooling system with an intermediate circuit
• 3 shows an alternative embodiment of the cooling system with an intermediate circuit
• FIG. 6 shows a cooling system with natural circulation and two intermediate circuits.
• the gas turbine system 1 according to FIG. 1 is part of a gas and steam turbine system, not shown in detail.
• the gas turbine system 1 has a turbine 2, which is preceded by a compressor 4 and a combustion chamber 6. Additional combustion chambers can also be provided.
• the or each combustion chamber 6 can be supplied as combustion air via a line 8 and thus compressed air V from the compressor 4 via the combustion air path.
• the combustion chamber 6 is connected to the turbine 2 via a line 10 or a connection.
• the turbine 2 can be supplied via the line 10 hot flue gas generated by combustion of a fuel.
• the turbine 2 and the compressor 4 are connected to one another via a turbine shaft 12.
• the turbine 2, the compressor 4, the combustion chamber 6, the lines 8, 10 and the turbine shaft 12 are also referred to in their entirety as a gas turbine.
• the compressor 4 is in turn connected to a generator 16 via a further shaft 14.
• the gas turbine plant 1 is designed for the highest possible efficiency.
• a high degree of efficiency is achieved in particular by a high inlet temperature of the flue gas the turbine 2 reached.
• Such a high turbine inlet temperature brings with it material problems, particularly with regard to the heat resistance of the turbine blades.
• the turbine blades are cooled to such an extent that they are always below the permissible material temperature.
• a partial stream branched off from the compressor air V can be fed as cooling air K.
• a cooling air line 17 is connected on the input side to the line 8 downstream of the compressor 4.
• the cooling air line 17 is connected to the turbine 2, so that the air provided as cooling air K can be fed to the guide vanes and the rotor blades of the turbine 2.
• a cooling system 18, which comprises a heat exchanger system 21 connected to the cooling air line 17 and having at least one heat exchanger 22, is used to recool the compressed air V provided as cooling air K.
• the heat exchanger 22 can be an auxiliary steam generator, also called a kettle boiler, and can be acted upon on the secondary side with a cooling medium, in particular water.
• the heat exchanger 22 is designed in particular in such a way that the medium to be cooled, that is to say the hot compressor air or compressed air V, is passed through a multiplicity of pipes, while the cooling medium (water) is supplied and generally evaporates.
• the cooling system 18 is designed for a particularly high degree of efficiency of the system with high flexibility at the same time.
• the cooling system 18 is designed to transfer heat carried in the cooling air K to the fuel gas stream 23, so that this heat can be used to preheat the fuel gas. This eliminates the external fuel gas preheater and components for cooling the cooling air K. In addition, this makes for everyone Operating conditions of the gas and steam turbine system suitable cooling system 18 a load reduction or load shutdown during it switching from pure gas turbine operation to gas and steam operation superfluous.
• the heat exchanger 22 is connected on the primary side into the cooling air line 17 and on the secondary side directly into a fuel gas line provided for guiding the fuel gas stream 23.
• the heat transfer from the cooling air K to the fuel gas stream 23 is achieved with only a small number of components. However, it could be taken into account in a conventional system design that the amount of heat to be extracted from the cooling air K for reliable operation of the turbine 2 exceeds the amount of heat that can be transferred to the fuel gas stream 23 due to the design.
• a division of the cooling air flow to be cooled back into two partial flows is provided in the exemplary embodiment according to FIG.
• a further heat exchanger 24 is connected in parallel in the heat exchanger system 21 to the heat exchanger 22.
• the cooling air flow is thus divided into two partial flows, the first partial flow being conducted via the cooling air line 17 via the heat exchanger 22 and the second partial flow being conducted via a branch line 26 branching off the cooling air line 17 via the further heat exchanger 24.
• the partial flows in the cooling air line 17 and the branch line 26 can also be set by means of fittings (not shown).
• the further heat exchanger 24 removes the heat that is not required for preheating the fuel gas and for another suitable use, for example as heat of vaporization.
• FIG. 2 An alternative embodiment of the cooling system 18 is shown in FIG. 2.
• the heat exchanger system 21 is designed for an indirect transfer of heat from the cooling air K to the fuel gas stream 23 with the interposition of an intermediate circuit 32.
• the cooling air K branched off from the compressor air V is guided through the cooling air line 17 via the first heat exchanger 22.
• the heat exchanger 22 is connected to the intermediate circuit 32 on the secondary side.
• a further heat exchanger 33 is connected in the intermediate circuit 32 and transfers heat to the fuel gas stream 23 for preheating the fuel gas.
• a separating bottle 34 connected downstream of the further heat exchanger 33 in the intermediate circuit 32 feeds the heat transfer medium, for example water, back to the heat exchanger 22. From the separating bottle 34 can also water or
• Steam is removed and fed, for example, to an auxiliary steam generator or consumers, not shown.
• the heat exchanger 22 can also be designed in a multi-component manner and comprise, for example, a segment designed as an auxiliary steam generator or kettle boiler via which a partial amount of the heat is supplied for other use. This is shown in FIG. 2 by the heating coil 35.
• the embodiment shown in FIG. 2 enables a particularly flexible removal and distribution of the heat extracted from the cooling air K via the intermediate circuit 32.
• the intermediate circuit 32 enables spatial decoupling of the essential functions, namely on the one hand the heat removal from the cooling air K and on the other hand the heat transfer to the fuel gas stream 23 from one another. Due to this decoupling, recourse to components already present in the system, such as heat exchangers, auxiliary steam generators or cooling circuits, is possible, with only an adjustment of the line routing being necessary. This concept is therefore particularly suitable for upgrading existing systems.
• the heat exchanger system 21 comprises the heat exchanger 22 connected on the primary side into the cooling air line 17, which is connected to a further heat exchanger 33 via an intermediate circuit 32.
• heat is thus transferred to the fuel gas via the intermediate circuit 32 and the further heat exchanger 33 connected on the secondary side into the fuel gas stream 30.
• the heat exchanger 22 is connected exclusively to the intermediate circuit 32 on the secondary side.
• a third heat exchanger 36 is provided for splitting the heat flows as required, which is connected on the primary side in series after the heat exchanger 22 into the cooling air line 17 and can therefore absorb residual heat still remaining in the cooling air K.
• the third heat exchanger 36 is connected on the secondary side to components which are suitably selected to absorb the residual heat.
• This circuit is particularly advantageous in that the third heat exchanger 36 merely dissipates the excess heat that cannot be used in the fuel gas stream 23
• Task as it may be in gas and steam turbines systems is the case. It is therefore largely not necessary to convert or replace existing components.
• FIG. 1 Another embodiment, also based on the use of an intermediate circuit 32, is shown in FIG.
• the cooling air K is cooled via the third heat exchanger 36 before it enters the heat exchanger 22.
• the intermediate circuit 32 is designed to use water / steam as a medium for heat transfer to the further heat exchanger 33.
• the heat exchanger 22 is designed as a steam generator in this case. The amount of heat transferred in the heat exchanger 22 is adjusted as required via the third heat exchanger 36.
• FIG. 5 An embodiment is also conceivable, as shown in FIG. 5, in which the heat transfer from the cooling air K to the fuel gas stream 23 takes place via a two-stage intermediate circuit system 40.
• the heat exchanger 22 connected on the primary side into the cooling air line 17 transfers heat from the cooling air K to a medium guided in a first intermediate circuit 42.
• a further heat exchanger 44 is connected in the intermediate circuit 42 on the primary side, which in turn transfers heat to a medium guided in a second intermediate circuit 46.
• the heat exchanger 48 is connected on the primary side, which transfers heat to the fuel gas stream.
• This embodiment has the advantage that the removal and use of the heat extracted from the cooling air K can be made particularly flexible.
• part of the heat not required for preheating the fuel gas can be generated in an auxiliary steam generator 50 downstream of the heat exchanger 48 in the second intermediate circuit 46 in order to generate in the auxiliary steam required in the system.
• Heat that is not required can be dissipated via an air cooler, not shown.
• this embodiment like the embodiment comprising the single-stage intermediate circuit, offers diverse possibilities for the use and the interconnection of components already present in the system.
• the water-steam mixture guided in the intermediate circuit 32 can be used to set a particularly high operational
• FIG. 6 shows an exemplary embodiment in which the rotor air cooling and the heating gas preheating are largely integrated into already existing power plant components.
• the cooling air K is fed via the cooling air line 17 to the heat exchanger 22 designed as a warp boiler, the required amount of heat being removed by evaporation.
• the steam generated on the secondary side can either be supplied to the heat exchanger 44 of the intermediate circuit system 40 configured as a condenser or to another consumer in the power plant via the auxiliary steam line 52.
• the intermediate circuit system 40 can in particular be designed as a natural circulation system, the heat exchanger 44 in turn being connected to a recooling system 51 on the secondary side.
• a partial flow of medium from the heat exchanger 22, which carries the amount of heat required for preheating the heating gas, is conducted via a line 54 via the heat exchanger 33 connected to the fuel gas stream 23 on the secondary side and then back into the heat exchanger 22.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Engine Equipment That Uses Special Cycles (AREA)
• Control Of Turbines (AREA)

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• 2003
  • 2003-07-14 WO PCT/DE2003/002363 patent/WO2004016921A1/de not_active Application Discontinuation
  • 2003-07-14 AU AU2003257386A patent/AU2003257386A1/en not_active Abandoned
  • 2003-07-14 JP JP2004528368A patent/JP2006509942A/ja not_active Abandoned
  • 2003-07-14 CN CNA03817653XA patent/CN1671956A/zh active Pending
  • 2003-07-14 EP EP03787660A patent/EP1525380A1/de not_active Withdrawn
  • 2003-07-14 US US10/521,904 patent/US20050241320A1/en not_active Abandoned
  • 2003-07-14 RU RU2005105070/06A patent/RU2005105070A/ru not_active Application Discontinuation
  • 2003-07-14 KR KR1020057001377A patent/KR20050025678A/ko not_active Application Discontinuation

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