Extra heat in a closed cycle power generation system, such as a reversible closed Brayton cycle system, may be dissipated between discharge and charge cycles. An extra cooling heat exchanger may be added on the discharge cycle and disposed between a cold side heat exchanger and a compressor inlet. Additionally or alternatively, a cold thermal storage medium passing through the cold side heat exchanger may be allowed to heat up to a higher temperature during the discharge cycle than is needed on input to the charge cycle and the excess heat then dissipated to the atmosphere.

The electrical power generation system including a micro-turbine including a combustor, a first stage turbine configured to be driven by a combustor exhaust from the combustor, at least one compressor operably connected to the combustor to provide a compressed airflow to the combustor, a catalytic converter configured convert the combustor exhaust to a catalytic exhaust that includes at least exothermic heat, a second stage turbine configured to be driven by the catalytic exhaust from the catalytic converter, and one or more shafts connecting the first stage turbine and the second stage turbine to the at least one compressor such that rotation of the first stage turbine and the second stage turbine drives rotation of the at least one compressor.

The electrical power generation system including a micro-turbine including a combustor, a first stage turbine configured to be driven by a combustor exhaust from the combustor, at least one compressor operably connected to the combustor to provide a compressed airflow to the combustor, a catalytic converter configured convert the combustor exhaust to a catalytic exhaust that includes at least exothermic heat, a second stage turbine configured to be driven by the catalytic exhaust from the catalytic converter, and one or more shafts connecting the first stage turbine and the second stage turbine to the at least one compressor such that rotation of the first stage turbine and the second stage turbine drives rotation of the at least one compressor.

An energy storage apparatus that includes at least one inlet for incoming process gas, at least one outlet for expanded process gas and a plurality of energy storage sub-systems configured to be arranged in series with each other and with a compressed gas store. The first of the plurality of energy storage sub-systems includes a first compressor, a first expander, a first thermal store and a first heat transfer device associated with the first thermal store. The second of the plurality of energy storage sub-systems includes a second compressor, at least a second expander, a second thermal store and a second heat transfer device associated with the second thermal store.

An energy storage apparatus that includes at least one inlet for incoming process gas, at least one outlet for expanded process gas and a plurality of energy storage sub-systems configured to be arranged in series with each other and with a compressed gas store. The first of the plurality of energy storage sub-systems includes a first compressor, a first expander, a first thermal store and a first heat transfer device associated with the first thermal store. The second of the plurality of energy storage sub-systems includes a second compressor, at least a second expander, a second thermal store and a second heat transfer device associated with the second thermal store.

A power plant including a compressor, a combustion chamber and a turbine, and a compressor air line, which connects the compressor to the combustion chamber, a first heat exchanger connected into the compressor air line and into an exhaust line branching off the turbine. A first expander is arranged between the first heat exchanger and the combustion chamber in the compressor air line, and the first expander and the compressor are arranged on a common shaft.

A power plant including a compressor, a combustion chamber and a turbine, and a compressor air line, which connects the compressor to the combustion chamber, a first heat exchanger connected into the compressor air line and into an exhaust line branching off the turbine. A first expander is arranged between the first heat exchanger and the combustion chamber in the compressor air line, and the first expander and the compressor are arranged on a common shaft.

Extra heat in a closed cycle power generation system, such as a reversible closed Brayton cycle system, may be dissipated between discharge and charge cycles. An extra cooling heat exchanger may be added on the discharge cycle and disposed between a cold side heat exchanger and a compressor inlet. Additionally or alternatively, a cold thermal storage medium passing through the cold side heat exchanger may be allowed to heat up to a higher temperature during the discharge cycle than is needed on input to the charge cycle and the excess heat then dissipated to the atmosphere.

The present disclosure provides systems and methods wherein power production can be achieved with combustion of a fuel utilizing flameless combustion. A fuel may be combusted in a combustor/turbine in a substantially flameless operation to produce a combustion product stream that can be expanded for power generation. After expansion, the output stream can be treated to generate a recycle CO.sub.2 stream into which an oxidant can be input. The recycle CO.sub.2 stream including the oxidant can be injected into the combustor/turbine to effect combustion in a substantially flameless state. Various control schemes can be implemented to automatically control the concentration of oxygen present in the recycle CO.sub.2 stream that is injected into the combustor/turbine in order to achieve and/or maintain substantially flameless combustion.

The present disclosure provides systems and methods wherein power production can be achieved with combustion of a fuel utilizing flameless combustion. A fuel may be combusted in a combustor/turbine in a substantially flameless operation to produce a combustion product stream that can be expanded for power generation. After expansion, the output stream can be treated to generate a recycle CO.sub.2 stream into which an oxidant can be input. The recycle CO.sub.2 stream including the oxidant can be injected into the combustor/turbine to effect combustion in a substantially flameless state. Various control schemes can be implemented to automatically control the concentration of oxygen present in the recycle CO.sub.2 stream that is injected into the combustor/turbine in order to achieve and/or maintain substantially flameless combustion.