US 5,647,221 AGranted

Pressure exchanging ejector and refrigeration apparatus and method

AssigneeThe George Washington University

InventorCharles A. Garris, Jr.

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Abstract

A novel ejector, an ejector-refrigeration system, and a method of refrigeration are disclosed. The system is particularly well suited for the utilization of energy sources such as waste heat from automobile engines and solar collectors. Further, the system is compatible with the use of environmentally benign refrigerant such as water. Unlike conventional ejectors, the novel ejector disclosed in the present invention is designed to utilize the principal of "pressure exchange" and is therefore capable of attaining substantially higher levels of performance than conventional ejectors whose operating mechanism is based on the principal of "turbulent mixing". The pressure exchanging ejector with a compressible working fluid utilizes the oblique compression and expansion waves occurring within jets emanating from the discharges of a plurality of supersonic nozzles so as to impart energy to a secondary gaseous fluid wherein the said waves are caused to move relative to the housing of said ejector by virtue of a motion inducing means applied to said nozzles, said nozzles being incorporated in a rotor. In the disclosed invention, the pressure exchanging ejector is utilized as an ejector-compressor with a vapor-compression refrigeration system whereby said working fluid constitutes the refrigerant.

An ejector compressor for transporting a compressible secondary fluid from a lower stagnation pressure supply to an ejector discharge of higher stagnation pressure, said ejector compressor utilizing pressure-exchange to affect energy transfer from an energetic primary compressible fluid to said secondary fluid, said ejector compressor comprising:

(a) an ejector housing preventing communication of the primary and secondary fluids with the environment;
(b) a primary fluid inlet duct;
(c) a plurality of supersonic nozzles of converging-diverging cross-section in the direction of flow whose inlets are in communication with said primary fluid inlet duct and which are integrated into a rotor such that the axis of discharge of one or more nozzles is located at a radial distance from the rotor's axis of rotation, said nozzles accelerate the primary fluid to supersonic speeds in such a manner as to produce compression and expansion waves in the region of the nozzle exit;
(d) said rotor being rotatably mounted in said ejector housing and provided with sealing means to minimize the communication of primary and secondary flows through flow paths other than the nozzles;
(e) rotation means so that the ratio of the peripheral speed of the nozzle to the speed of the primary fluid immediately after the compression waves is greater than 0.1.
(f) a secondary fluid inlet conduit;
(g) aerodynamic flow control surfaces interior to said housing and in the conduit of the secondary fluid placed upstream and in the vicinity of the nozzles to increase the speed of the secondary flow and to bring it into direct contact with the primary fluid in the vicinity of the nozzle exits;
(h) a pressure exchange zone in the interior of said housing and bounded by aerodynamic surfaces which may include the rotor, the housing, a center-body, or an after-body to insure the direct action of the rotating pressure wave structure on the secondary fluid;
(i) a discharge duct for the combined flow.

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Abstract

Claims21