Rotary screw compressor rotor having work extraction mechanism
A gas compressor is disclosed that includes a first rotor having a first rotor body, the first rotor body including a plurality of helical lobes, an infernal volume within the first rotor body defined by a wall, and a turbine disposed within the internal volume, the turbine including a turbine body and a plurality of airfoils extending substantially radially from the turbine body to the wall, where the internal volume is structured to enable a cooling fluid to flow therethrough. The gas compressor further includes a second rotor body including a plurality of helical flutes, an inlet manifold and an outlet manifold, both disposed within the second rotor body, and a body channel within at least one flute extending from and in fluid communication with the inlet manifold to the outlet manifold, where the body channel is structured to enable a cooling fluid to flow therethrough.
1. An apparatus comprising:
a compressor rotor having an external helical compression surface structured for engagement with a complementary shaped compressor rotor to form a rotary screw compressor, the external helical compression surface including a helical valley formed between adjacent helical walls, the compressor rotor having;
an inlet aperture into which passes a cooling fluid for passage to an interior of the compressor rotor;
an outlet aperture from which passes the cooling fluid;
the helical walls defining an open interior volume located between the inlet aperture and outlet aperture, the helical walls forming an internal helical surface, and
a plurality of turbine blades disposed in the open interior volume, respective ones of the plurality of turbine blades having an airfoil shape oriented to extract work from the cooling fluid traversing through the open interior volume such that total pressure of the cooling fluid is decreased as the cooling fluid flows between the inlet aperture and the outlet aperture as a result of the extraction of work via the plurality of turbine blades, wherein the plurality of turbine blades extend outwardly from a central body and are fixed in position internal to the compressor rotor and relative to the external helical compression surface such that the plurality of turbine blades and the central body rotate with the external helical compression surface of the compressor rotor.
2. The apparatus of claim 1 , wherein the central body is disposed interior to the open interior volume and axially separated from an upstream entrance to the open interior volume and a downstream exit from the open interior volume such that a spatial offset is provided.
3. The apparatus of claim 2 , wherein the plurality of turbine blades are integral with the helical walls and central body.
4. The apparatus of claim 2 , which further includes an impingement face disposed in an upstream portion of the open interior volume to increase turbulence of the cooling fluid and thereby increase heat transfer from the helical compression surface to the cooling fluid.
5. The apparatus of claim 4 , wherein the plurality of turbine blades are arranged in one of: (1) staged rows; and (2) a helical pattern between an upstream end of the compressor rotor and a downstream end of the compressor rotor.
6. The apparatus of chum 8 , wherein the turbine is one of an impulse turbine and a reactive turbine.
7. The apparatus of claim 6 , wherein the compressor rotor is a male rotor having lobes.
8. The apparatus of claim 7 , wherein a cross sectional area of the open interior increases in a direction of flow of the fluid when it traversed through the open interior.