Power plant unit for a hybrid power plant

A power plant unit comprising:

• a turbine, the turbine comprising
• a turbine housing,
• a flow channel for a compressible medium arranged in the turbine housing, wherein the flow channel has a drive side and an output side, wherein the compressible medium in the flow channel flows from the drive side to the output side, wherein a flow cross-section of the flow channel increases from the drive side to the output side so that the compressible medium can expand,
• a drive shaft and at least one output impeller arranged in the flow channel, wherein the at least one output impeller comprises an output shaft for operating a generator, wherein the output shaft is set into a rotational movement by means of the at least one output impeller when the compressible medium flows through the at least one output impeller, wherein the at least one output impeller is connected to the output shaft in a rotationally fixed manner, wherein the drive shaft and the output shaft are mechanically decoupled, and
• a circulation device comprising a fluid passage for the compressible medium, wherein the circulation device is configured such that a first partial volume of the compressible medium flows into the flow channel at the drive side and a second partial volume of the compressible medium flows into the flow channel at the output side and upstream of the at least one output impeller.

A method for operating a power plant including a turbine, wherein the turbine is arranged in a turbine housing, wherein a flow channel for a compressible medium is arranged in the turbine housing, wherein the flow channel has a drive side and an output side, wherein the compressible medium in the flow channel flows from the drive side to the output side, wherein a flow cross-section of the flow channel increases from the drive side to the output side so that the compressible medium expands, wherein a drive shaft and at least one output impeller are arranged in the flow channel, wherein the at least one output impeller comprises an output shaft, wherein the at least one output impeller is connected to the output shaft in a rotationally fixed manner, wherein the drive shaft and the output shaft are mechanically decoupled, wherein a circulation device comprising a fluid passage for the compressible medium is provided, wherein the circulation device is configured such that a first partial volume of the compressible medium flows into the flow channel at the drive side and a second partial volume of the compressible medium flows into the flow channel at the output side and upstream of the at least one output impeller, the method comprising:

• flowing the first partial volume of the compressible medium into the flow channel at the drive side,
• flowing the second partial volume of the compressible medium into the flow channel at the output side and upstream of the at least one output impeller,
• generating a rotational movement of the drive shaft of the turbine by the compressible medium,
• generating a rotational movement of the output shaft by means of the compressible medium flowing through the at least one output impeller, wherein the rotational movement of the drive shaft takes place independently of the rotational movement of the output shaft by means of the drive shaft and the output shaft being mechanically decoupled, and
• driving a generator with the output shaft to generate electrical energy.