The present invention provides methods and system for power generation using a high efficiency combustor in combination with a CO.sub.2 circulating fluid. The methods and systems advantageously can make use of a low pressure ratio power turbine and an economizer heat exchanger in specific embodiments. Additional low grade heat from an external source can be used to provide part of an amount of heat needed for heating the recycle CO.sub.2 circulating fluid. Fuel derived CO.sub.2 can be captured and delivered at pipeline pressure. Other impurities can be captured.

A system for warming an engine. The system includes an engine coolant system that directs warm engine coolant to the engine to heat the engine. A heat pump system warms the engine coolant.

A thermal energy recovery system. The system includes a Stirling engine having a burner thermal energy output. Also, a superheater mechanism for heating the thermal energy output and an expansion engine coupled to a generator. The expansion engine converts the thermal energy output from the burner to mechanical energy output. The generator converts mechanical energy output from the expansion engine to electrical energy output. The expansion engine may also includes vapor output. Some embodiments of the system further include a condenser for condensing the vapor output, a pump for pumping the vapor output and a boiler in fluid communication with the pump. The pump pumps the vapor output to the boiler.

A thermal energy recovery system. The system includes a Stirling engine having a burner thermal energy output. Also, a superheater mechanism for heating the thermal energy output and an expansion engine coupled to a generator. The expansion engine converts the thermal energy output from the burner to mechanical energy output. The generator converts mechanical energy output from the expansion engine to electrical energy output. The expansion engine may also includes vapor output. Some embodiments of the system further include a condenser for condensing the vapor output, a pump for pumping the vapor output and a boiler in fluid communication with the pump. The pump pumps the vapor output to the boiler.

Method for operating an arrangement for using waste heat of an internal combustion engine, wherein the internal combustion engine has an exhaust gas duct and the arrangement for using waste heat has a circuit conveying a working medium. In the circuit are arranged, in the flow direction of the working medium, a pump, at least one evaporator, an expansion machine and a condenser. The at least one evaporator is also arranged in the exhaust gas duct, wherein in the at least one evaporator an exhaust gas expelled from the internal combustion engine is used as a heat source, and thus the working medium is evaporated in the evaporator. The method according to the invention detects, inside the at least one evaporator, a leakage of the working medium into the exhaust gas duct.

Method for operating an arrangement for using waste heat of an internal combustion engine, wherein the internal combustion engine has an exhaust gas duct and the arrangement for using waste heat has a circuit conveying a working medium. In the circuit are arranged, in the flow direction of the working medium, a pump, at least one evaporator, an expansion machine and a condenser. The at least one evaporator is also arranged in the exhaust gas duct, wherein in the at least one evaporator an exhaust gas expelled from the internal combustion engine is used as a heat source, and thus the working medium is evaporated in the evaporator. The method according to the invention detects, inside the at least one evaporator, a leakage of the working medium into the exhaust gas duct.

A heat recovery system has an evaporator in which a working medium is evaporated, an expander by means of which energy from the working medium in vapor form is made usable, a recuperator operating as an internal heat exchanger, a condenser that condenses the working medium in vapor form, and a pump to move the working medium through a circuit. At least one plate heat exchanger with flow channels formed in interspaces between the heat exchanger plates is provided as a component of the system and includes at least the recuperator and the condenser.

A heat recovery system has an evaporator in which a working medium is evaporated, an expander by means of which energy from the working medium in vapor form is made usable, a recuperator operating as an internal heat exchanger, a condenser that condenses the working medium in vapor form, and a pump to move the working medium through a circuit. At least one plate heat exchanger with flow channels formed in interspaces between the heat exchanger plates is provided as a component of the system and includes at least the recuperator and the condenser.

A machine for converting thermal energy originating from waste heat deposits into electrical energy. It uses the magnetic phase transition properties of certain materials when they are exposed to a temperature variation with respect to their Curie temperature. The machine includes a magnetothermal converter provided with a fixed stator provided with active elements made of the materials, and a mobile rotor provided with magnetic poles and non-magnetic poles. The machine includes a closed fluidic circuit of heat-transfer fluid, coupled with two thermal sources of different temperatures by means of heat exchangers and with the stator to transfer thermal energy collected in the active elements. A synchronization system makes it possible to expose the active elements to alternating thermal cycles to generate a permanent magnetic imbalance between the rotor and the stator, and generate a displacement of the rotor, creating mechanical energy that can be converted into electrical energy.

Envisaged is a regeneration system for a metal hydride heat pump of a damper type. The system comprises a plurality of reactor assembly modules configured to act as a heat pump, an ambient air inlet and a fluid recirculation circuit. The plurality of reactor assembly modules includes first, second, third and fourth metal hydride reactor assembly modules. The fluid recirculation circuit comprises a mixer, a fluid stream switching means, a flow regulating means and an exhaust outlet. The mixer is adapted to mix a portion of a recirculation stream received from the exhaust outlet and the exhaust gas stream to provide a resultant stream. The fluid stream switching means is coupled to the mixer and is adapted to switch flow of the resultant stream as received from the mixer and the ambient air stream in a cyclic manner in a series of half-cycles of operation.