Hermetic turbine generator
AssigneeMechanical Technology Incorporated
InventorsJohn S. Meacher, David E. Ruscitto
Life of this patent
Estimating the term…
Abstract
A Rankine cycle turbine drives an electric generator and a feed pump, all on a single shaft, and all enclosed within a hermetically sealed case. The shaft is vertically oriented with the turbine exhaust directed downward and the shaft is supported on hydrodynamic fluid film bearings using the process fluid as lubricant and coolant. The selection of process fluid, type of turbine, operating speed, system power rating, and cycle state points are uniquely coordinated to achieve high turbine efficiency at the temperature levels imposed by the recovery of waste heat from the more prevalent industrial processes.
Claims17
A power generating system for recovering energy from a low temperature heat source that includes
- a heat exchanger for transferring energy from a low temperature source to a low boiling point refrigerant to vaporize said refrigerant,
- a sealed housing for supporting a rotor shaft vertically therein,
- a feed pump secured to the upper end of the shaft for pumping vapor from the heat exchanger to the inlet of a turbine secured to the lower end of the shaft to drive an electrical generator operatively connected to the shaft intermediate said feed pump and said turbine whereby the turbine supports at least a portion of the rotor when it reaches operational speed,
- a condenser connected to the housing directly beneath the turbine for reducing refrigerant vapors discharged from the turbine to a liquid,
- an upper bearing means connected to said shaft between said vapor pump and said generator,
- a lower bearing means connected to said shaft between said turbine and said generator,
- a boost pump for moving refrigerant from the condenser to the feed pump and into both said bearing means whereby said refrigerant is permitted to gravity flow through said bearing means to cool and lubricate said bearing means, and
- flow directing means for gravity feeding liquid refrigerant leaving the upper bearing means over the surfaces of the electrical generator for cooling said generator.
A power unit for a Rankine cycle turbine driven electrical power generating system having a heat exchanger for vaporizing a working fluid;
- a vapor turbine having a rotating turbine wheel driven by said vaporized working fluid, a condenser for cooling and condensing said working fluid exhausted from said turbine;
- a feed pump having a rotating impeller for pumping the working fluid condensed in said condenser to said heat exchanger;
- and an induction electric generator having a rotor driven by said turbine for generating electric power;
- wherein the improvement comprises:
- a hermetically sealed housing enclosing said turbine, said generator, and said feed pump;
- said housing having a longitudinal axis oriented vertically;
- a rotor assembly, including a single shaft extending along said longitudinal axis and having mounted thereon for rotation therewith said feed pump impeller, said generator rotor, and, at the lower axial end of said shaft, said turbine wheels;
- a hydraulic support system for said rotor that further includes a source of pressurized liquid working fluid, a double acting tilt pad thrust bearing having a thrust runner connected to the shaft, and a casing enclosing the regions above and below the thrust runner so that said regions can be pressurized;
- and
- first and second fluid lines, respectively connected to the casing regions above and below the thrust runner, a spring loaded control valve in said first line that is normally biased to a closed position at the time the unit is initially started to pressurize the region below the thrust runner and thus support the rotor at start-up, said valve being automatically moved to an open position when the rotor reaches operating speed to pressurize both regions with fluid when the unit is running at operating speed.
Dependencies are inferred from the claim text.