Abstract: The invention relates to methods and systems for liquefaction of gases whose critical temperature is lower than the ambient temperature, such as, for instance, natural gas, air, nitrogen, oxygen, etc. Compressed to supercritical pressure gas to be liquefied is cooled by external refrigerator means to a predetermined final temperature that is lower than the saturation temperature of the liquefied gas, and then is throttled to a subcritical pressure. As a result, all gas supplied to the apparatus is liquefied without generating any flash gas, and controlled rate of liquefied gas subcooling is achieved. Three modifications of the apparatus for gas liquefaction employing refrigerator means, based on reversed gas cycles, are introduced. Another modification of the apparatus with refrigerator means applying open air cycle and Compressed Air Energy Storage (CAES) is also developed.

Abstract: A compressed air energy storage (CAES) system utilizes compressed air stored in a cavity for electric power and cold production. During periods of excess power production, atmospheric air is compressed then cooled in stages using energy from a motor/generator. Condensed water is then separated from the air which is then stored in a cavity. When there is an energy demand from the CAES system, the stored compressed air is heated using heat from an external low grade energy source such as refrigerated substances, surrounding water, surrounding air, waste heat sources and solar energy. The heated compressed air is then expanded through a plurality of expansion stages to provide mechanical power to the motor/generator for generating electricity.

Abstract: Gas turbine with a bottoming air turbine cycle. This system comprises a gas turbine and a bottoming air turbine cycle system. The latter includes a gas-to-air heat exchanger, compressed air aftercooler, an air compressor, a hot air turbine, and a cold air turbine. High temperature exhaust gases of the gas turbine pass the heat exchanger heating compressed air delivered by the air compressor. Then hot air expands in the hot air turbine. Part of the air from the compressor is cooled in the aftercooler, and then expands in the cold air turbine. Hot and cold air turbines drive the air compressor and an electric generator or other consumer of mechanic power. After the cold air turbine, air temperature is lower than the ambient temperature. Using it, refrigeration can be provided, including cooling gas turbine compressor inlet air. In this mode, the gas turbine compressor consumes air having stabilized low temperature and stabilized pressure. A special peak load mode of the gas turbine is also available.