Unitary sliding vane compressor-expander and electrical generation system

A unitary sliding vane type compressor-expander, comprising:

• a compressor portion with a compressor inlet and a compressor outlet;
• an expander portion with an expander inlet and an expander outlet;
• and
• an integral condenser-humidifier disposed in fluid communication with the expander outlet for condensing water out of the expanded gas and returning the condensed water directly to the expander outlet.

A unitary compressor-expander comprising:

• a housing having a compressor side with a compressor inlet and a compressor outlet, and an expander side with an expander inlet and an expander outlet;
• a cylindrical rotor disposed within the housing and having a plurality sliding vanes disposed in slots around an outer periphery thereof, wherein the vanes are configured to slide outwardly along the slots upon rotation of the rotor, and sealingly contact an inner contoured surface of the housing;
• a vane magnet in at least one of the vanes;
• at least one stationary magnet in the housing disposed about the inner contacting surface, wherein the poles of the vane magnet are substantially aligned with the direction of the vane and its corresponding slot, and the poles of the at least one stationary magnet are substantially aligned with the vanes and slots as they pass by the stationary magnet, wherein a first one of said at least one stationary magnets is oriented to repel the vane magnet, and a second one of said at least one stationary magnets is oriented to attract the vane magnet.

A method for improving the efficiency of a fuel cell electrical generation system, comprising the steps of:

• providing a fuel cell for generating output electrical power having an oxidant inlet, an oxidant outlet, a fuel inlet, and a fuel exhaust;
• connecting a unitary vane type compressor-expander to the fuel cell, comprising:
• a housing having a compressor side with a compressor inlet port and a compressor outlet port, and an expander side with an expander inlet port and an expander outlet port;
• a cylindrical rotor disposed within the housing and having a plurality sliding vanes disposed in slots around an outer periphery thereof, wherein the vanes are configured to slide inward and outward along the slots upon rotation of the rotor, thereby maintaining contact with an inner contoured surface of the housing and simultaneously compressing oxidant gas on the compressor side of the housing and expanding oxidant gas on the expander side of the housing;
• driving the unitary compressor expander with a motor, powered by electricity derived from the fuel cell electrical generation system, by means of an output shaft of the motor connected to the cylindrical rotor of the compressor-expander for rotationally driving the cylindrical rotor;
• compressing air drawn from the compressor inlet on in the compressor side of the compressor-expander;
• supplying the compressed air to an oxidant inlet of the fuel cell for reacting with fuel introduced through the fuel inlet;
• and
• expanding the spent oxidant gas from the fuel cell across the expander side of the compressor-expander.