Abstract: A turbine system for a multistage turbocharger and a method for utilizing the same are disclosed. The turbine system includes a high pressure turbine having an inlet for receiving a flow of fluid, and an outlet for passing the flow on extraction of work from the high pressure turbine. The system further includes a low pressure turbine, having an inlet for receiving a flow of fluid from the high pressure turbine. A diffuser connects the outlet of the high pressure turbine and the inlet of the low pressure turbine. The system also includes a bypass channel for bypassing a portion of the flow around the high pressure turbine, from upstream of the high pressure turbine to downstream of the high pressure turbine. The system includes an injector to input the bypass flow in the diffuser in a manner to reduce flow separation in the diffuser.

Abstract: A turboexpander-compressor system includes an expander configured to expand an incoming gas, a first set of moveable inlet guide vanes configured to control a pressure of the incoming gas, a compressor configured to compress a gas received from the expander, a shaft configured to support and rotate an expander impeller and a compressor impeller, a second set of moveable inlet guide vanes attached to the compressor and configured to control a pressure of the gas input into the compressor, and a controller configured to acquire information about a rotating speed of the shaft, a pressure and a temperature of the incoming gas, a pressure and a temperature of the gas output from the expander, and to control the second set of moveable inlet guide vanes to maximize a ratio between the rotating speed of the shaft and a drop of an enthalpy across the expander, in off-design conditions.

Abstract: A method and system for power generation including a turboexpander with at least two expansion stages, the turboexpander being connected to a power generation unit, is provided. The system includes a controller configured to control (i) an angle of a first inlet guide vane provided at an inlet of a first expansion stage of the turboexpander for maintaining an inlet pressure of the first expansion stage in a predetermined range, and (ii) an angle of a second inlet guide vane provided at an inlet of a second expansion stage of the turboexpander. The controller is configured to determine a highest power from determined powers of the power generation unit and a corresponding angle of the second inlet guide vane and to adjust the angle of the second inlet guide vane independent of the angle of the first inlet guide vane to achieve the highest power.

Abstract: Systems include using a turboexpander in power generation systems. The system includes: a turboexpander to include an expander section, a pump section and a motor-generator section which are mechanically linked via a shaft. The expander section is fluidly connected to an outlet side of a heat exchanger and configured to receive a vapor stream of a fluid, to rotate the shaft and to generate an expanded vapor stream of the fluid. The pump section is fluidly connected to an outlet side of a condenser and configured to receive a liquid stream of the fluid, to pressurize the liquid stream of the fluid and to circulate the fluid in the power generation system. The motor-generator section is configured to output an electrical current.

Abstract: A system for recovering energy in a gas compression plant. The system comprises at least one centrifugal compressor configured to suck the gas, at a certain inlet pressure, from a suction conduit and configured to deliver the gas, at a certain outlet pressure that is greater than an inlet pressure, through a delivery conduit The system also includes at least one gas recirculation system configured to redirect the gas from the delivery conduit to the suction conduit when the gas flow rate entering into the compressor is below a certain limit value. In the portion of the plant arranged downstream of the compressor, at least one turbo-expander and at least one valve are installed in parallel so that they cooperate with each other and are controlled by electronic devices so as to protect the compressor and to produce useful energy during recirculation mode.