Method and installation for storing and recovering energy

Abstract

The invention relates to a method for storing and recovering energy, according to which a condensed air product (LAIR) is formed in an energy storage period, and in an energy recovery period, a pressure flow is formed and is expanded to produce energy using at least part of the condensed air product (LAIR) without a supply of heat from an external heat source. The method comprises inter alia, for the formation of the condensed air product (LAIR): the compression of air (AIR) in an air conditioning unit ( 10 ), at least by means of an adiabatically operated compressor device ( 12 ); the formation of a first and a second sub-flow downstream of the adiabatically driven compressor device ( 12 ), said flows being formed from the air (AIR) that has been compressed in said device and the guiding of the first and second sub-flows in parallel through a first thermal store ( 131 ) and through a second thermal store ( 132 ), in which stores heat produced during the compression of the air (AIR) is at least partially stored. For the formation of the pressure flow, a vaporized product (HPAIR) is produced inter alia from at least one part of the condensed air product (LAIR). During the energy-producing expansion process, the pressure flow is guided through a first expansion device ( 61 ) and a second expansion device ( 62 ) and is thus expanded in each device. Heat stored in the first heat store device ( 131 ) is transferred to the pressure flow upstream of the first expansion device ( 61 ) and heat stored in the second heat store device ( 132 ) is transferred to the pressure flow upstream of the second expansion device ( 62 ). The invention also relates to an installation ( 100 ).

1 . A method for storing and recovering energy in which, in an energy storage period, an air liquefaction product is formed and, in an energy recovery period, a pressurized stream is formed and expanded to perform work by using at least part of the air liquefaction product without a supply of heat from an external heat source, the method comprising,
 for the formation of the air liquefaction product,   compressing at a superatmospheric pressure level air in an air conditioning unit, at least by means of an adiabatically operated compressor device, and adsorptively purifying the air by means of at least one adsorptive purification device,   forming a first sub-stream and a second sub-stream in the air conditioning unit downstream of the adiabatically operated compressor device from the air compressed in this compressor device and conducting the first and second sub-streams in parallel through a first heat storage device and a second heat storage device,   storing heat generated during the compression of the air at least partly in the first heat storage device and the second heat storage device,   liquefying at a liquefaction pressure level in a range of 40 to 100 bara the compressed and adsorptively purified air, starting from a temperature level in a range of 0 to 50° C., in a first fraction in a fixed-bed cold storage unit and in a second fraction in a counterflow heat exchanger unit, and   subsequently expanding the liquefied air in at least one cold production unit,   and, for the formation of the pressurized stream,   producing a vaporization product from at least part of the liquefaction product at a vaporization pressure level, which deviates by no more than 5 bar from the liquefaction pressure level, in the fixed-bed cold storage unit, and   conducting the pressurized stream during the work-performing expansion through a first expansion device and a second expansion device and thereby respectively expanding the pressurized stream, and   upstream of the first expansion device, transferring to the pressurized stream heat stored in the first heat storage device and, upstream of the second expansion device, transferring to the pressurized stream heat stored in the second heat storage device.   
     
     
         2 . The method as claimed in  claim 1 , which comprises using a fixed-bed heat storage medium and/or a liquid heat storage medium in at least one of the heat storage devices. 
     
     
         3 . The method as claimed in  claim 1 , which comprises transferring a heat storage fluid between at least two storage tanks in at least one of the heat storage devices and transferring the heat from or to the at least one heat storage fluid in at least one heat exchanger. 
     
     
         4 . The method as claimed in  claim 1 , which comprises heating a heat storage medium in at least one of the heat storage devices up to a temperature level of 50 to 400° C. 
     
     
         5 . The method as claimed in  claim 1 , one of the in which a generator turbine is used respectively as the first expansion device and as the second expansion device. 
     
     
         6 . The method as claimed in  claim 1 , which comprises feeding to the at least one adsorptive purification device a regenerating gas, which is formed from part of the air that is previously compressed and adsorptively purified in the air conditioning unit. 
     
     
         7 . The method as claimed in  claim 6 , which comprises forming the regenerating gas during the energy storage period from at least part of an evaporation product formed during the expansion of the liquefied air. 
     
     
         8 . The method as claimed in  claim 6 , which comprises forming the regenerating gas during the energy recovery period from at least part of the vaporization product. 
     
     
         9 . The method as claimed in  claim 1 , which comprises conducting an evaporation product formed during the expansion of the liquefied air through the counterflow heat exchanger unit. 
     
     
         10 . The method as claimed in  claim 1 , which comprises conducting at least one cold transfer medium that is provided by means of an external cold circuit and/or is formed by expansion from part of the air previously compressed and adsorptively purified in the air conditioning unit through the counterflow heat exchanger unit. 
     
     
         11 . An installation, which is designed for storing and recovering energy by forming an air liquefaction product in an energy storage period and by generating, and expanding to perform work, a pressurized stream formed by using at least part of the air liquefaction product without a supply of heat from an external heat source in an energy recovery period, the installation having means which are designed,
 for the formation of the air liquefaction product,   to compress at a superatmospheric pressure level air in an air conditioning unit, at least by means of an adiabatically operated compressor device, and adsorptively purify the air by means of at least one adsorptive purification device,   to form a first sub-stream and a second sub-stream in the air conditioning unit downstream of the adiabatically operated compressor device from the air compressed in the latter and to conduct the first and second sub-streams in parallel through a first heat storage device and a second heat storage device,   to store heat generated during the compression of the air at least partly in the first heat storage device and the second heat storage device,   to liquefy at a liquefaction pressure level in a range of 40 to 100 bara the compressed and adsorptively purified air, starting from a temperature level in a range of 0 to 50° C., in a first fraction in a fixed-bed cold storage unit and in a second fraction in a counterflow heat exchanger unit, and   subsequently to expand the liquefied air in at least one cold production unit,   and, for the formation of the pressurized stream,   to produce a vaporization product from at least part of the liquefaction product at a vaporization pressure level, which deviates by no more than 5 bar from the liquefaction pressure level, in the fixed-bed cold storage unit, and   to conduct the pressurized stream during the work-performing expansion through a first expansion device and a second expansion device and thereby respectively expand the pressurized stream, and   upstream of the first expansion device, to transfer to the pressurized stream heat stored in the first heat storage device and, upstream of the second expansion device, transfer to the pressurized stream heat stored in the second heat storage device.   
     
     
         12 . The installation as claimed in  claim 11 , which has means that are designed for carrying out a method for storing and recovering energy.