System and method for generating power

Abstract

A system and method for generating power involves a heater for heating condensate to generate at least partially vaporized fluid for supply to a boundary-layer turbine, which extracts energy therefrom. An axial turbine of the system is coupled to the boundary-layer turbine to receive the fluid therefrom to extract energy. A boundary-layer turbomachine of the system is coupled to the axial turbine to receive the fluid therefrom and to generate the condensate for the heater. Each of the boundary-layer turbine and turbomachine includes a corresponding plurality of ducts for receiving the fluid therein, which corresponding plurality of ducts are defined by a corresponding plurality of duct walls that are configured for drivable rotation by the fluid azimuthally frictionally dragging the respective plurality of duct walls. The plurality of duct walls of the boundary-layer turbomachine are configured to condense the fluid to generate the condensate for the heater.

What is claimed is: 
     
         1 . A system for generating power, comprising:
 a heater for transferring heat to condensate to generate fluid that is at least partially vaporized;   a boundary-layer turbine including a first plurality of ducts configured to receive the fluid from the heater and at least partially defined by a corresponding first plurality of duct walls that are configured for drivable rotation about a first longitudinal axis of the boundary-layer turbine by the fluid frictionally dragging the first plurality of duct walls at least partially azimuthally around the first longitudinal axis of the boundary-layer turbine, the first plurality of duct walls configured to transfer energy from the fluid flowing in the first plurality of ducts;   an axial turbine coupled to the boundary-layer turbine to receive the fluid from the boundary-layer turbine to extract energy from the fluid; and   a boundary-layer turbomachine coupled to the axial turbine to receive the fluid from the axial turbine into a second plurality of ducts at least partially defining the boundary-layer turbomachine, the second plurality of ducts at least partially defined by a corresponding second plurality of duct walls that are configured for drivable rotation about a second longitudinal axis of the boundary-layer turbomachine by the fluid frictionally dragging the second plurality of duct walls at least partially azimuthally around the second longitudinal axis of the boundary-layer turbomachine, the second plurality of duct walls configured to condense the fluid flowing in the second plurality of ducts to generate the condensate for the heater.   
     
     
         2 . The system of  claim 1 , wherein the boundary-layer turbine comprises:
 a first plurality of blades rotatably disposed around the first longitudinal axis at a downstream end of a duct of the first plurality of ducts, the first plurality of blades adapted to receive the fluid oriented at least partially azimuthally around the first longitudinal axis and to redirect the fluid generally parallel to the first longitudinal axis, the fluid thereby imparting rotation to the plurality of blades about the first longitudinal axis to generate power.   
     
     
         3 . The system of  claim 2 , wherein the first plurality of blades extend radially relative to the first longitudinal axis from a duct wall of the duct and are integrally formed with the duct wall for co-rotation with the duct wall. 
     
     
         4 . The system of  claim 2 , wherein the first plurality of blades extend radially relative to the first longitudinal axis from a first duct wall of the duct to a second duct wall of the duct opposed the first duct wall. 
     
     
         5 . The system of  claim 2 , wherein the axial turbine is configured to receive the fluid oriented generally parallel to the longitudinal axis downstream of the plurality of blades. 
     
     
         6 . The system of  claim 5 , wherein the axial turbine includes a vaned stator axially aligned along the first longitudinal axis and a bladed rotor axially aligned with the vaned stator, the bladed rotor disposed downstream of the vaned stator. 
     
     
         7 . The system of  claim 1 , wherein the boundary-layer turbine further comprises: a shaft drivably coupled to the first plurality of ducts, the shaft being coaxial with the first plurality of ducts and circumferentially surrounded by the first plurality of ducts. 
     
     
         8 . The system of  claim 7 , wherein the boundary-layer turbine comprises:
 a plurality of tubes nested concentrically around the first longitudinal axis, spaced apart from each other, and having progressively larger cross-sectional areas lateral to the first longitudinal axis,   
       wherein each of the first plurality of ducts is formed between a pair of concentrically adjacent tubes of the plurality of tubes, and the shaft is disposed coaxially inside an inner cavity formed by a radially-innermost tube of the plurality of tubes at least partially defining a radially-innermost duct of the first plurality of ducts. 
     
     
         9 . The system of  claim 1 , wherein the boundary-layer turbine is configured to receive the fluid via an inlet end and discharge the fluid via an outlet end, the boundary-layer turbine further comprising:
 one or more flow inlets disposed at the inlet end and configured to receive the fluid into the first plurality of ducts at least partially azimuthally around the first longitudinal axis towards the outlet end in accordance with rotation of the first plurality of duct walls of the first plurality of ducts, the fluid being frictionally engaged with the first plurality of duct walls to transfer mechanical energy to, or from, the fluid flowing in the first plurality of ducts, the one or more flow inlets being configured to draw the fluid into the first plurality of ducts to impart rotation to the first plurality of duct walls to generate power.   
     
     
         10 . The system of  claim 9 , wherein a flow inlet of the one or more flow inlets is configured to draw the fluid into an upstream end of a duct of the first plurality of ducts generally azimuthally around the first longitudinal axis, and a longitudinal length of the duct is adapted to limit an azimuthal deviation of the fluid to at most 10 degrees. 
     
     
         11 . The system of  claim 9 , wherein the boundary-layer turbine comprises:
 a first plurality of blades rotatably disposed around the first longitudinal axis at a downstream end of a duct of the first plurality of ducts, the first plurality of blades adapted to receive the fluid oriented at least partially azimuthally around the first longitudinal axis and to redirect the fluid generally parallel to the first longitudinal axis, the fluid thereby imparting rotation to the plurality of blades about the first longitudinal axis to generate power,   wherein leading edges of the first plurality of blades are adapted to an azimuthal deviation of the fluid along the duct to receive the fluid in substantial alignment therewith.   
     
     
         12 . The system of  claim 1 , wherein the boundary-layer turbine is configured to receive the fluid via an inlet end and discharge the fluid via an outlet end, the boundary-layer turbine further comprising:
 one or more flow inlets disposed at the inlet end and configured to receive the fluid into the first plurality of ducts at least partially azimuthally around the first longitudinal axis towards the outlet end in accordance with rotation of the first plurality of duct walls of the first plurality of ducts, the fluid being frictionally engaged with the first plurality of duct walls to transfer mechanical energy to, or from, the fluid flowing in the first plurality of ducts, the one or more flow inlets being configured to draw the fluid into the first plurality of ducts to impart rotation to the first plurality of duct walls to generate power,
 wherein the one or more flow inlets draw the fluid into an upstream end of a duct of the first plurality of ducts oriented within 10 degrees of an azimuthal direction around the first longitudinal axis. 
   
     
     
         13 . The system of  claim 1 , wherein the boundary-layer turbine further comprises:
 a slot opening into a duct of the second plurality of ducts and radially spaced apart from a radially-inner wall of the duct to receive a first portion of the fluid to draw the first portion of the fluid out of the duct while allowing a second portion of the fluid to remain in the duct, the first portion of the fluid being separated from the second portion of the fluid by being drawn centrifugally towards the slot relative to the second portion of the fluid; and   a flow outlet configured to receive the second portion of the fluid from the duct to discharge the second portion of the fluid out of the boundary-layer turbine.   
     
     
         14 . The system of  claim 1 , wherein the boundary-layer turbine further comprises:
 one or more protrusions extending radially in a duct of the first plurality of ducts and spirally extending along and around the first longitudinal axis in the duct to define walls of a spiral channel in the duct for receiving and drawing the fluid from one or more flow inlets of the boundary-layer turbine into and along the duct, an inlet of the spiral channel azimuthally oriented to receive the fluid supplied by the one or more flow inlets.   
     
     
         15 . The system of  claim 1 , wherein the boundary-layer turbomachine is configured to impart energy to the fluid via compression to cause condensation to generate the condensate. 
     
     
         16 . The system of  claim 1 , wherein the boundary-layer turbine is a first boundary-layer turbine and the boundary-layer turbomachine is a second boundary-layer turbine. 
     
     
         17 . A method of generating power using a working fluid configured to change phase for generating power, comprising:
 imparting heat to condensate to cause at least partial vaporization of the condensate to generate the working fluid;   receiving the working fluid on blades of a turbine rotor to drivably rotate the turbine rotor to generate shaft power;   receiving the working fluid flowing at least partially azimuthally from the turbine rotor into a duct defined between a first duct wall and a second duct wall, the first duct wall and second duct wall circumferentially extending around a longitudinal axis and elongated along the longitudinal axis, the first duct wall being radially-separated from the second duct wall; and   driving rotatably the first duct wall and the second duct wall by frictionally engaging the first duct wall and the second duct wall with the working fluid in the duct to exchange energy with the working fluid to cause condensation of the working fluid to generate the condensate.   
     
     
         18 . The method of  claim 17 , wherein a protrusion from the first duct wall radially extends to the second duct wall and spirally extends at least partially along the longitudinal axis to draw the working fluid along the duct. 
     
     
         19 . The method of  claim 17 , further comprising:
 using the shaft power to drive an electric generator; and   cooling the electric generator using the condensate to preheat the condensate.   
     
     
         20 . The method of  claim 17 , wherein imparting heat to the condensate to cause at least partial vaporization of the condensate to generate the working fluid includes using a heater configured to receive the condensate, the method further comprising:
 using the shaft power to drive an electric generator;   preheating the condensate in a heat exchanger using heat from the electric generator; and   receiving the condensate into the heater via the heat exchanger.   
     
     
         21 . The method of  claim 17 , wherein the working fluid is imparted energy via compression to cause condensation to generate the condensate.