Abstract: An electric generator includes a process gas inlet on a downstream side of the flow control valve to receive process gas into the electric machine; a rotor shaft including a node position, the node position defining a position of a node of a first bending mode of the rotor shaft; a turbine wheel coupled to the rotor shaft at the node position, the turbine wheel configured to receive process gas and rotate in response to expansion of the process gas flowing into an inlet of the turbine wheel and out of the outlet of the turbine wheel, the rotor shaft configured to rotate with the turbine wheel, and a stationary stator, the electric generator to generate an alternating current upon rotation of the rotor within the stator. The turbine wheel selected from a plurality of turbine wheels based on the operational conditions of the electric generator.

Abstract: A system includes an electric generator, a power electronics system, a first heat exchanger, and a second heat exchanger. The electric generator includes a turbine wheel, a rotor, and a stator. The turbine wheel is configured to receive process gas and rotate in response to expansion of the process gas flowing through the electric generator. The rotor is configured to rotate with the turbine wheel. The electric generator is configured to generate electrical power upon rotation of the rotor within the stator. The power electronics system is configured to receive the electrical power from the electric generator and convert the electrical power to specified power characteristics. A heat transfer fluid receives waste heat from the power electronics system through the first heat exchanger. The heat transfer fluid transfers the received waste heat to the process gas through the second heat exchanger.

Abstract: A first turboexpander generator is configured to decrease a temperature or pressure of a process stream flowing through the first turboexpander generator by generating electrical power from the process stream. A second turboexpander generator is configured to decrease a temperature or pressure of a process stream flowing through the second turboexpander generator by generating electrical power from the process stream. The second turboexpander generator is downstream of and receives a flow output from the first turboexpander generator. The first turboexpander generator and the second turboexpander generator each include the following features. An electric stator surrounds an electric rotor. An annulus defined by the electric rotor and the electric stator is configured to receive a process fluid flow. Magnetic bearings carry the rotor within the stator. A housing encloses the rotor and stator. The housing is hermetically sealed between an inlet and an outlet of each turboexpander generator.

Abstract: An electric power generation system receives a gas flow at a heater, heats the gas flow at the heater with a heated fluid from a waste heat process, and directs the heated gas flow to a turbine wheel of an electric generator. The heated gas flow drives rotation of the turbine wheel, and in response to rotating the turbine wheel, electrical current is generated by the electric generator. Generated electrical current is then directed to power electronics.

Abstract: A system includes an electric generator, a power electronics system, and a heat exchanger. The electric generator includes a turbine wheel, a rotor, and a stator. The turbine wheel is configured to receive process gas and rotate in response to expansion of the process gas flowing into an inlet of the turbine wheel and out of an outlet of the turbine wheel. The rotor is configured to rotate with the turbine wheel. The electric generator is configured to generate electrical power upon rotation of the rotor within the stator. The power electronics system is configured to convert the electrical power to specified power characteristics. The heat exchanger includes a first side in fluid communication with the process gas and a second side in fluid communication with a fluid stream from a second system. The heat exchanger is configured to cool the fluid stream using the process gas.