Methods and systems are provided for an in-cylinder thermal energy recovery device that utilizes the Rankine Cycle to recover energy from exhaust gasses that may be used to produce additional work in the vehicle. In one example, a method may include outfitting the head area of each cylinder of an engine with a tube array comprising one or more tubes passing through the combustion chamber of the corresponding cylinder. Each tube array may receive an injection of working fluid that is based, in part, on the temperature of the tube array's corresponding cylinder, which may then be utilized to recover heat energy.

An Organic Rankine Cycle (ORC) Waste Heat Recovery (WHR) System has an LT working fluid loop and an HT working fluid loop. The working fluid loops may each have a pump, one or more heat exchanger boilers, an expander, and a condenser. A recuperator is arranged within the LT working fluid loop between the pump and the first heat exchanger boiler. The recuperator is also arranged within the HT working fluid loop between the expander and the pump, or within the LT working fluid loop between the expander and the condenser. One of the heat exchanger boilers in the LT loop may be a charge air cooler heat exchanger, and may receive charge air mixed with recirculating exhaust gas. The LT loop may include more than one heat exchanger boiler, arranged in series or in parallel. Bypass valves may selectively bypass one or more of the heat exchangers.

Methods and systems are provided for an in-cylinder thermal energy recovery device that utilizes the Rankine Cycle to recover energy from exhaust gasses that may be used to produce additional work in the vehicle. In one example, a method may include outfitting the head area of each cylinder of an engine with a tube array comprising one or more tubes passing through the combustion chamber of the corresponding cylinder. Each tube array may receive an injection of working fluid that is based, in part, on the temperature of the tube array's corresponding cylinder, which may then be utilized to recover heat energy.

A method and apparatus for operating an internal combustion engine, in particular for commercial vehicles, having a fuel/air feed device and a downstream exhaust system, wherein, to achieve improved efficiency, the exhaust gas enthalpy in the exhaust gas flow of the internal combustion engine is used to operate a heat engine, in particular a Stirling engine, which produces mechanical energy.

An internal combustion engine heat energy recovery system (1) comprises a first heat exchanger (20) arranged in heat communication with at least one heat energy source of an internal combustion engine (10) and with a working fluid of the system (1) for the transfer of heat energy from the heat energy source to the working fluid of the system (1). A turbine (30) is arranged in fluid communication with the working fluid heated in the first heat exchanger (20) for the expansion of the working fluid to produce shaft power. A second heat exchanger (40) is arranged in heat communication with the expanded working fluid to remove waste heat therefrom and transfer it to an external source such as the atmosphere. A first compressor (50) is arranged in fluid communication with the working fluid exiting the heat exchanger for increasing the pressure of the cooled working fluid prior to its entry into the first heat exchanger (20). The working fluid of the system is a substantially supercritical fluid.

The disclosure relates to a system and method for recovering waste heat to improve the response and fuel economy of a machine. The system includes a heat recovery apparatus and an engine. The heat recovery apparatus has a cold cylinder, a first piston disposed in the cold cylinder, a hot cylinder, a second piston disposed in the hot cylinder, and a regenerator. The first piston and the second piston are in fluid communication with one another via the regenerator. The engine produces heat from multiple sources. A first heat source produced by the engine is thermally coupled to the regenerator and a second heat source produced by the engine is thermally coupled to the hot cylinder. The heat recovery apparatus is configured to convert the heat generated by the first and second heat sources into mechanical energy.