A waste heat recovery system comprising a thermal circuit. The thermal circuit includes a boiler and an expander fluidly coupled to the boiler. The thermal circuit further includes a power transfer system integrated to the expander. The power transfer system is configured to receive mechanical energy from the expander. The thermal circuit further includes an ejector fluidly coupled to the boiler and to the power transfer system. The ejector is configured to receive a motive flow of working fluid from the boiler. The ejector is further configured to receive a suction flow of working fluid from the power transfer system. The ejector is further configured to combine the motive flow of working fluid and the suction flow of working fluid.

A waste heat recovery device with a first heat medium side inlet; a first heat medium side outlet; a first heat medium flow path; a second heat medium side inlet; a second heat medium side outlet; a second heat medium flow path; a heat exchanger that exchanges heat between the first heat medium and second heat medium; an expansion tank in the first heat medium flow path; a bypass flow path that causes the first heat medium to flow and bypass the heat exchanger; and a mixer where the bypass flow path and first heat medium flow path merge together. The mixer is configured to adjust a ratio of a flow rate of the first heat medium in the bypass flow path and a flow rate of the first heat medium in the heat exchanger, such that the temperature of the first heat medium after merging approaches a predetermined temperature.

A waste heat recovery device with a first heat medium side inlet; a first heat medium side outlet; a first heat medium flow path; a second heat medium side inlet; a second heat medium side outlet; a second heat medium flow path; a heat exchanger that exchanges heat between the first heat medium and second heat medium; an expansion tank in the first heat medium flow path; a bypass flow path that causes the first heat medium to flow and bypass the heat exchanger; and a mixer where the bypass flow path and first heat medium flow path merge together. The mixer is configured to adjust a ratio of a flow rate of the first heat medium in the bypass flow path and a flow rate of the first heat medium in the heat exchanger, such that the temperature of the first heat medium after merging approaches a predetermined temperature.

An energy recovery device comprising a drive mechanism; an engine comprising a plurality of Shape Memory Alloy (SMA) elements or Negative Thermal Expansion (NTE) elements fixed at a first end by a holder element and connected at a second end to a drive mechanism wherein Shape Memory Alloy (SMA) elements or Negative Thermal Expansion (NTE) elements are positioned to from a gap between adjacent elements and configured to improve heat transfer from a fluid to each element.

An energy recovery device comprising a drive mechanism; an engine comprising a plurality of Shape Memory Alloy (SMA) elements or Negative Thermal Expansion (NTE) elements fixed at a first end by a holder element and connected at a second end to a drive mechanism wherein Shape Memory Alloy (SMA) elements or Negative Thermal Expansion (NTE) elements are positioned to from a gap between adjacent elements and configured to improve heat transfer from a fluid to each element.

A system includes an exhaust passage and a waste heat recovery system. The exhaust passage is structured to fluidly couple to an exhaust manifold of an engine, and to receive exhaust gas from the engine. The waste heat recovery system includes a working fluid circuit, a superheater, and an expander. The working fluid circuit includes a pump to circulate a working fluid through the working fluid circuit, including through the engine. Heat is transferred from the engine to the working fluid. The superheater is positioned along the working fluid circuit downstream of the engine. The superheater is fluidly coupled to the exhaust passage and transfers heat from the exhaust gas to the working fluid. The expander is positioned along the working fluid circuit downstream of the superheater. The expander generates useful energy from the heat transferred to the working fluid from the exhaust gas and the engine.

A system includes an exhaust passage and a waste heat recovery system. The exhaust passage is structured to fluidly couple to an exhaust manifold of an engine, and to receive exhaust gas from the engine. The waste heat recovery system includes a working fluid circuit, a superheater, and an expander. The working fluid circuit includes a pump to circulate a working fluid through the working fluid circuit, including through the engine. Heat is transferred from the engine to the working fluid. The superheater is positioned along the working fluid circuit downstream of the engine. The superheater is fluidly coupled to the exhaust passage and transfers heat from the exhaust gas to the working fluid. The expander is positioned along the working fluid circuit downstream of the superheater. The expander generates useful energy from the heat transferred to the working fluid from the exhaust gas and the engine.

A combined heat and power system, or an energy system, is provided. A four-stroke opposed-piston engine provides efficient power from a generator set or genset. A heat exchange system is provided within the energy system to provide efficient waste heat recovery as the engine is operated.

Systems and generating power in an organic Rankine cycle (ORC) operation to supply electrical power. In embodiments, an inlet temperature of a flow of gas from a source to an ORC unit may be determined. The source may connect to a main pipeline. The main pipeline may connect to a supply pipeline. The supply pipeline may connect to the ORC unit thereby to allow gas to flow from the source to the ORC unit. Heat from the flow of gas may cause the ORC unit to generate electrical power. The outlet temperature of the flow of the gas from the ORC unit to a return pipe may be determined. A bypass valve, positioned on a bypass pipeline connecting the supply pipeline to the return pipeline, may be adjusted to a position sufficient to maintain temperature of the flow of gas above a threshold based on the inlet and outlet temperature.

Systems and generating power in an organic Rankine cycle (ORC) operation to supply electrical power. In embodiments, an inlet temperature of a flow of gas from a source to an ORC unit may be determined. The source may connect to a main pipeline. The main pipeline may connect to a supply pipeline. The supply pipeline may connect to the ORC unit thereby to allow gas to flow from the source to the ORC unit. Heat from the flow of gas may cause the ORC unit to generate electrical power. The outlet temperature of the flow of the gas from the ORC unit to a return pipe may be determined. A bypass valve, positioned on a bypass pipeline connecting the supply pipeline to the return pipeline, may be adjusted to a position sufficient to maintain temperature of the flow of gas above a threshold based on the inlet and outlet temperature.