The present invention concerns a method of utilising the waste heat contained in the exhaust gas of an internal combustion engine, comprising a turbine (20). To provide an apparatus and a method of operating same which directly supplies additional drive energy which otherwise would be lost as waste heat, it is proposed according to the invention that the turbine is an inverse turbine connected downstream of the exhaust gas outlet of the internal combustion engine and comprising at the inlet side an expansion stage (23) and at the outlet side a subsequent compressor (21), wherein the expansion stage and the compressor of the inverse turbine are so designed that the downstream-disposed compressor of the inverse turbine generates at the outlet of the expansion stage (23) a reduced pressure (p1) below the ambient pressure (p0), wherein the outlet (2b) of the compressor (21) is at the level of the ambient pressure and the compressor of the inverse turbine is driven by the turbine.

A hybrid compressed air energy storage system is provided. A heat exchanger 114 extracts thermal energy from a compressed air to generate a cooled compressed air stored in an air storage reservoir 120, e.g., a cavern. A heat exchanger 124 transfers thermal energy generated by a carbon-neutral thermal energy source 130 to cooled compressed air conveyed from reservoir 120 to generate a heated compressed air. An expander 140 is solely responsive to the heated compressed air by heat exchanger 124 to produce power and generate an expanded air. Expander 140 is effective to reduce a temperature of the expanded air by expander 140, and thus a transfer of thermal energy from an expanded exhaust gas received by a recuperator 146 (used to heat the expanded air by the first expander) is effective for reducing waste of thermal energy in exhaust gas cooled by recuperator 146.

A hybrid compressed air energy storage system is provided. A heat exchanger 114 extracts thermal energy from a compressed air to generate a cooled compressed air stored in an air storage reservoir 120, e.g., a cavern. A heat exchanger 124 transfers thermal energy generated by a carbon-neutral thermal energy source 130 to cooled compressed air conveyed from reservoir 120 to generate a heated compressed air. An expander 140 is solely responsive to the heated compressed air by heat exchanger 124 to produce power and generate an expanded air. Expander 140 is effective to reduce a temperature of the expanded air by expander 140, and thus a transfer of thermal energy from an expanded exhaust gas received by a recuperator 146 (used to heat the expanded air by the first expander) is effective for reducing waste of thermal energy in exhaust gas cooled by recuperator 146.

A system includes a temperature control system configured to couple to an air intake section of a gas turbine system. The temperature control system includes a variable heating system having one or more heaters configured to heat an airflow in the air intake section when the airflow is cooled by an evaporative cooling system. The temperature control system is configured to control the variable heating system to vary an amount of heat supplied by the one or more heaters based on at least one temperature measurement relative to a temperature threshold.

A thermal management system for a heat engine, the system including an forming at least in part a core flowpath and a cavity, wherein the core flowpath and the cavity are separated by a double wall structure formed by at least a portion of inner wall, and wherein the double wall structure includes a plenum. A first opening provides fluid communication between the cavity and the plenum, and a second opening provides fluid communication between the plenum and the core flowpath. The inner wall is configured to receive a first flow of fluid. An outer wall forms a passage extended at least partially around the core flowpath. The outer wall is configured to receive a second flow of fluid fluidly separated from the core flowpath.

A system for cooling a gas turbine with an exhaust gas provided by the gas turbine generally includes an exhaust gas recirculation system including an exhaust gas scrubber. The exhaust gas recirculation system is disposed downstream from the gas turbine and may receive at least a portion of the exhaust gas provided by the gas turbine. The system may also include a moisture separator located downstream from the exhaust gas recirculation system, and a cooling circuit configured to connect to one or more cooling circuit inlets. The one or more cooling circuit inlets may provide fluid communication between the cooling circuit and the gas turbine.

A system for cooling a gas turbine with an exhaust gas provided by the gas turbine generally includes an exhaust gas recirculation system including an exhaust gas scrubber. The exhaust gas recirculation system is disposed downstream from the gas turbine and may receive at least a portion of the exhaust gas provided by the gas turbine. The system may also include a moisture separator located downstream from the exhaust gas recirculation system, and a cooling circuit configured to connect to one or more cooling circuit inlets. The one or more cooling circuit inlets may provide fluid communication between the cooling circuit and the gas turbine.

Disclosed is a station (100) for expanding a flow of gas having, at the inlet, a temperature T.sub.a and a pressure P.sub.a, that comprises: an expansion valve (105) for recovering mechanical expansion energy configured to reduce the pressure of the gas flow to a pressure P.sub.b and to a temperature T.sub.b such that P.sub.b<P.sub.a and T.sub.b<T.sub.a; a compressor (110) for compressing a flow of fluid having, at the inlet, a temperature T.sub.c and a pressure P.sub.c; the expansion valve and the compressor are linked mechanically such that the movement of the expansion valve when the gas expands causes the compressor to be actuated such that the fluid is compressed to a pressure P.sub.d and a temperature T.sub.d such that P.sub.d>P.sub.c and T.sub.d>T.sub.c; and a heat exchanger (115) for exchanging heat between the gas flow at the outlet or inlet of the expansion valve and the fluid flow at the outlet or inlet of the compressor in order to heat the gas and cool the fluid.

One embodiment includes a multistage infrared suppression exhaust system for an aircraft, including: a stage one including a first exhaust conduit to receive a first exhaust air flow at a first temperature-pressure product T.sub.1P.sub.1, a second exhaust conduit to receive a second exhaust air flow at a second temperature-pressure product T.sub.2P.sub.2, and a flow integrator mechanically configured to mix the first exhaust air flow with the second exhaust air flow in an integration chamber while preventing back pressure into the second exhaust conduit; and a stage two including a stage two cooling airflow to cool the mixed first and second exhaust air flows.

One embodiment includes a multistage infrared suppression exhaust system for an aircraft, including: a stage one including a first exhaust conduit to receive a first exhaust air flow at a first temperature-pressure product T.sub.1P.sub.1, a second exhaust conduit to receive a second exhaust air flow at a second temperature-pressure product T.sub.2P.sub.2, and a flow integrator mechanically configured to mix the first exhaust air flow with the second exhaust air flow in an integration chamber while preventing back pressure into the second exhaust conduit; and a stage two including a stage two cooling airflow to cool the mixed first and second exhaust air flows.