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
  • F02C6/00—Plural gas-turbine plants; Combinations of gas-turbine plants with other apparatus; Adaptations of gas-turbine plants for special use
  • F02C6/003—Gas-turbine plants with heaters between turbine stages
• • 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
  • F02C1/00—Gas-turbine plants characterised by the use of hot gases or unheated pressurised gases, as the working fluid
  • F02C1/04—Gas-turbine plants characterised by the use of hot gases or unheated pressurised gases, as the working fluid the working fluid being heated indirectly
  • F02C1/05—Gas-turbine plants characterised by the use of hot gases or unheated pressurised gases, as the working fluid the working fluid being heated indirectly characterised by the type or source of heat, e.g. using nuclear or solar energy
  • F02C1/06—Gas-turbine plants characterised by the use of hot gases or unheated pressurised gases, as the working fluid the working fluid being heated indirectly characterised by the type or source of heat, e.g. using nuclear or solar energy using reheated exhaust gas
• • 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
  • F02C6/00—Plural gas-turbine plants; Combinations of gas-turbine plants with other apparatus; Adaptations of gas-turbine plants for special use
  • F02C6/14—Gas-turbine plants having means for storing energy, e.g. for meeting peak loads
  • F02C6/16—Gas-turbine plants having means for storing energy, e.g. for meeting peak loads for storing compressed air
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/16—Mechanical energy storage, e.g. flywheels or pressurised fluids

Definitions

• This invention relates generally to the recovery of energy from compressed air in a Compressed Air Energy Storage (CAES) system.
• CAES Compressed Air Energy Storage
• CAES Compressed Air Energy Storage
• CAES plants store off-peak energy from relatively inexpen ⁇ sive energy sources such as coal and nuclear baseload plants by compressing air into storage devices such as underground caverns or reservoirs. This compressed air is then withdrawn from storage during intermediate or peak power demand periods, and is heated, combined with fuel and expanded through expanders, i.e., turbines, to provide needed power. Since inexpensive off-peak energy is used to compress the air, the need for premium fuels, such as natural gas and imported oil, is reduced by as much as about two thirds compared with conventional gas turbines.
• Compressors and turbines in CAES plants are each connected to a generator/motor device through respective clutches, permitting operation either solely of the compressors or solely of the turbines during appropriate selected time periods.
• the turbine clutch is disengaged and the compressor train is driven through its clutch by the generator/motor.
• the generator/motor func- tions as a motor, drawing power from a power grid. The compressed air is then cooled and delivered to underground storage.
• air is withdrawn from storage, is heated with a first combustor to a temperature of up to 1000 degrees Fahrenheit, and is then expanded to a low pressure com- pressed air by a first, high pressure expander, preferably a turbine.
• the first expander thus recovers most of the energy in the high pressure compressed air.
• the low pressure compressed air is then heated with a second combustor to a temperature of about 1600 degrees Fahren- heit, and is then passed through a second, low pressure expander, also a turbine, to recover additional energy from the stored compressed air.
• a recuperator recovers heat from the exhaust gases of the second, low pressure expand ⁇ er, which are generally at between 600 to 700 degrees Fahrenheit, and uses the heat to help the first combustor preheat the high pressure compressed air, prior to induc ⁇ tion into the first, high pressure expander.
• CAES compression air energy storage
• a system for recovering energy from a high pressure compressed gas includes a first, high pressure expander for receiving the high pressure compressed gas and expanding the high pressure compressed gas to a lower pressure compressed gas to produce mechanical energy; a second, low pressure expander for receiving the lower pressure compressed gas and for expanding the lower pressure compressed gas to an exhaust gas to produce additional mechanical energy,- a combustor interposed between the first expander and the second expander for heating the low pressure compressed gas before it is inducted into the second expander; and a recuperator for recovering heat energy from the exhaust gas of the second expander and for heating the high pressure compressed gas with the recovered heat energy before the high pressure compressed gas is inducted into the first, high pressure expander; wherein no heat source other than the recuperator is provided for directly heating the high pressure com ⁇ pressed gas, and the combustor is of sufficient capacity to heat the low pressure compressed gas to a temperature that will ensure the exhaust gas of the second expander is hot enough to permit the recuperator to sufficiently heat the high pressure compressed gas.
• FIGURE 1 is a schematic depiction of an improved compressed air energy storage system that is constructed according to a preferred embodiment of the invention.
• an improved compressed air energy storage (CAES) system 10 that is constructed according to a preferred embodiment of the invention includes a motor/generator 12 for converting mechanical energy into electrical energy, and vice versa, depending upon the mode that CAES system 10 happens to be in.
• motor/generator 12 is coupled to a compressor 16 via a drive mechanism that includes a clutch 14, so that when electricity is applied to motor/generator 12, clutch 14 may be engaged, causing compressor 16 to compress atmospheric air and supply the high pressure compressed air to a air storage cavern or chamber 18 via a first pressure conduit 20.
• a valve 22 is interposed in first pressure conduit 20.
• a second pressure conduit 24 is communicated with air storage cavern 18.
• a valve 26 is interposed in second pressure conduit 24.
• Improved CAES system 10 advantageously includes an improved system 28 for recovering energy from the high pressure compressed gas that is stored in cavern or chamber 18.
• Improved recovery system 28 includes a high pressure expander 30, a low pressure expander 32, a combustor 34 that is interposed between high pressure expander 30 and low pressure expander 32, and a recuperator 36.
• the high pressure and low pressure expanders 30, 32 are mechanically coupled to motor/generator 12 via a drive train that has a second clutch 38 interposed therein, as is clearly shown in FIGURE 1.
• combustor 34 which preferably operates on liquid propane, is of sufficient capacity so as to be able to heat the low pressure compressed air that is exhausted from high pressure expander 30 sufficiently so that exhaust gases from low pressure expander 30 are hot enough that recuperator 36 can recover enough heat from the exhaust gases to adequately heat the high pressure com- pressed air supplied to high pressure expander 30 without the need for a separate combustor prior to high pressure expander 30.
• combustor 34 is capable of heating the low compressor compressed air between high pressure expander 30 and low pressure expander 32 to a temperature of between 2070 to 2500 degrees Fahrenheit, at a pressure of between 210 to 235 psi. Most preferably, the air is heated to about 2300°F at a pressure of approximately 220 psi.
• mo- tor/generator 12 In operation, electrical energy is supply to mo- tor/generator 12 during off-peak periods, and mo ⁇ tor/generator 12 drives compressor 16 to introduce high pressure compressed air into an air storage cavern or chamber 18.
• high pressure compressed air from cavern 18 is introduced into second pressure conduit 24 by opening valve 26.
• This high pressure compressed air is passed through recuperator 36, and is heated by the exhaust gases from low pressure expander 32 prior to being supplied to inlet of high pressure expander 30.
• High pressure expander 30 receives the high pressure compressed air and expands the high pressure compressed air to a lower pressure compressed air to produce mechanical energy, which is transmitted to mo- tor/generator 12 and converted to electricity that is supplied to a power grid.
• the lower pressure compressed air that is exhausted from high pressure expander 30 is supplied to combustor 34, which heats the low pressure compressed air to a temperature of approximately 2300°F .
• the heated low temperature compressed air is supplied to low pressure expander 32, which expands the low pressure compressed air to exhaust gas to produce additional mechanical energy that is transmitted to motor/generator 12 and converted into additional electricity.
• the exhaust gases are at a temperature of approximately 950° to 1050°F. This temperature is sufficient to enable recuperator 36 to recover enough energy to adequately heat the high pressure compressed gas prior pressure expander 30 without the need for an additional combustor at that point. As a result, substantial cost savings are achieved.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Life Sciences & Earth Sciences (AREA)
• High Energy & Nuclear Physics (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Engine Equipment That Uses Special Cycles (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=23043133

Family Applications (1)

Country Status (3)

Cited By (12)

Citations (4)

• 1995
  • 1995-05-30 WO PCT/US1995/006779 patent/WO1996001942A1/en active Application Filing
  • 1995-06-05 TW TW084105612A patent/TW289068B/zh active
  • 1995-07-03 IL IL11443695A patent/IL114436A0/xx unknown

Patent Citations (4)

Non-Patent Citations (1)

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