Symbol of the Government of Canada


Patent Document Number: 2755930

(54) English Title: SYSTEM AND METHOD FOR POWER STORAGE AND RELEASE

(54) French Title: SYSTEME ET PROCEDE DE STOCKAGE ET DE LIBERATION D'ENERGIE


Claims:

Note: Claims are shown in the official language in which they were submitted.



CLAIMS

1. An energy release system comprising:
a storage apparatus;
one or more heat exchangers, at least one of the heat exchangers being fluidly

connected to the storage apparatus;
at least one combustion chamber fluidly connected to at least one of the heat
exchangers;
one or more generator-loaded hot-gas expanders fluidly connected to the at
least
one combustion chamber and at least one of the heat exchangers;
at least one generator fluidly connected to at least one of the hot-gas
expanders,
the generator producing electric power; and
a stream of liquid air and a stream of working loop air, the stream of liquid
air and
the stream of working loop air being separate and distinct streams, the
working loop air traveling
in a closed loop such that liquid air released from the storage apparatus
flows in a first general
direction, and working loop air flows in a second general direction, the
second general direction
being substantially opposite to the first general direction; and
the working loop air warms the released liquid air such that the released
liquid air
is substantially vaporized, and the released liquid air cools the working loop
air such that the
working loop air is substantially liquefied.


2. The system of claim 1 wherein a portion of the released liquid air is
directed to the at
least one generator and used as bearing air for the at least one generator.


3. The system of claim 1 wherein the substantially vaporized air is directed
to a combustion
chamber and combusted with a fuel stream.


4. The system of claim 1 wherein the substantially liquefied working loop air
is pumped to
pressure and vaporized by hot combustion gas; and
the vaporized high pressure working loop air is expanded in a generator-loaded

hot-gas expander, wherein the generator produces electric power.


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5. The system of claim 3 wherein combustion gas is directed from the
combustion chamber
to at least one generator-loaded hot gas expander and expanded in the
generator-loaded hot-gas
expander;
the expanded combustion gas is split into a first portion and a second
portion, the
first portion being relatively larger than the second portion;
the first portion is directed to a first heat exchanger; and
the second portion is directed to a second heat exchanger such that the second

portion heats and substantially vaporizes the released liquid air.


6. The system of claim 1 further comprising a liquid air production system,
the liquid air
production system comprising:
one or more inlet air compressors;
a molecular sieve assembly fluidly connected to a first inlet air compressor;
a vertical cold flue assembly fluidly connected to the molecular sieve
assembly
and to a second inlet air compressor, the vertical cold flue assembly having
an air inlet at or near
its top into which inlet air is directed and an exit at or near its bottom;
one or more inlet air heat exchangers including a main heat exchanger fluidly
connected to at least one of the plurality of inlet air compressors;
a storage apparatus fluidly connected to the main heat exchanger;
an absorption chiller using a working fluid, the absorption chiller being
fluidly
connected to the cold flue assembly; and
a mechanical chiller containing refrigerant fluid, the mechanical chiller
being
fluidly connected to the absorption chiller; and
a refrigerant loop air assembly fluidly connected to the mechanical chiller.

7. The system of claim 6 wherein the refrigerant loop air assembly comprises:
one or more refrigerant loop air compressors, at least one of the plurality of

refrigerant loop air compressors being fluidly connected to the main heat
exchanger;
one or more refrigerant loop air cryogenic expanders;

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wherein the mechanical chiller is fluidly connected to at least one
refrigerant loop
air compressor, at least one refrigerant loop air cryogenic expander, the
absorption chiller, and to
the main heat exchanger; and
wherein refrigerant loop air flows from the refrigerant loop assembly to the
main
heat exchanger to cool the inlet air.


8. The system of claim 7 wherein the refrigerant loop air is compressed by the
one or more
refrigerant loop air compressors and the heat of compression is recovered by
at least the
absorption chiller.


9. The system of claim 8 wherein the refrigerant loop air is split such that a
first portion is
directed to the mechanical chiller and a second portion is directed to at
least one refrigerant loop
air cryogenic expander;
the refrigerant loop air is cooled by the mechanical chiller and by the one or
more
refrigerant loop air cryogenic expanders and is directed to the main heat
exchanger; and
the refrigerant fluid within the mechanical chiller is condensed by cold
working
fluid sent to the mechanical chiller from the absorption chiller.


10. The system of claim 6 wherein recovered cold from a vapor portion of the
substantially
liquefied air further cools the inlet air in the main heat exchanger;
the vapor portion of the substantially liquefied air is warmed by heat from
the
inlet air and recovered heat of compression; and
the warmed vapor portion of the substantially liquefied air is directed to the

molecular sieve assembly such that the vapor portion of the substantially
liquefied air removes
carbon dioxide and moisture from the molecular sieve assembly.


11. A method of releasing stored energy comprising:
releasing stored liquid air via a valve;
pumping the released liquid air to pressure using at least one cryogenic pump;

creating a closed loop containing working loop air such that the released
liquid air
and the working loop air are separate and distinct streams;


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directing the released liquid air through at least one heat exchanger in a
first
general direction;
directing working loop air through the at least one heat exchanger such that
the
working loop air flows in a second general direction, the second general
direction being
substantially opposite to the first general direction;
warming the released liquid air with the working loop air such that the
released
liquid air is substantially vaporized; and
cooling the working loop air with the released liquid air such that the
working
loop air is substantially liquefied.


12. The method of claim 11 further comprising the steps of:
directing a portion of the released liquid air to at least one generator; and
using the released liquid air as bearing air for the at least one generator;
wherein the released liquid air cools the generator and the generator warms
the
released liquid air.


13. The method of claim 11 further comprising the steps of:
pumping the substantially liquefied working loop air to pressure;
vaporizing the pressurized liquid working loop air by heat exchange with hot
combustion gas;
expanding the pressurized working loop air in a generator-loaded hot-gas
expander such that the generator produces electric power.


14. The method of claim 11 further comprising the steps of:
directing the substantially vaporized and pressurized air to a combustion
chamber;
and
combusting the substantially vaporized air with a fuel stream.

15. The method of claim 14 further comprising the steps of:
directing combustion gas from the combustion chamber to a first generator-
loaded
hot-gas expander; and


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expanding the combustion gas in the at least one generator-loaded hot-gas
expander.


16. The method of claim 15 further comprising the steps of:
splitting the expanded combustion gas into a first portion and a second
portion,
the first portion being relatively larger than the second portion;
directing the first portion to a main heat exchanger to warm a cold
pressurized air
stream;
directing the second portion to a second heat exchanger such that the second
portion heats and substantially vaporizes the liquid air in the loop that is
used to recover the cold
from the main released air, where the loop air is heated and expanded in a
second generator-
loaded hot-gas expander.


17. The method of claim 13 further comprising the steps of:
directing the formerly hot exhaust stream from the main heat exchanger to a
moisture separator;
recovering moisture from the hot exhaust stream in the moisture separator;
pumping the recovered liquid moisture to pressure;
warming the moisture by recovered heat in a warm heat exchanger; and
directing the recovered moisture to the first generator-loaded hot-gas
expander.