Compression method and means

Abstract

The invention is a compression method having characteristics of smooth compression and internal cooling of the gas. Embodiments of the invention employ a cylindrical chamber and an orbiting rotor to create a moving duct or chamber whose walls converge, relative to a static gas packet drawn into the moving duct, at a ‘pinch point’. Preferably the closing speed of the walls is subsonic and the speed of the pinch point is supersonic. This enables high pressure to co-exist, at the narrowing end of the duct, with low pressure elsewhere in the duct, because of the pressure information barrier produced by the supersonic advance of the pinch point. The invention also discloses means for adjusting the running clearance between the cylinder and the rotor, and means for counterbalancing the rotor.

Description

[0001]This application relates to the field of gas pumping and compression.BACKGROUND OF THE INVENTION[0002]Gas compression devices used in refrigeration, air conditioning and industry consume a large portion of electrical power generated. An increase in gas pumping efficiency will result in reduction of carbon dioxide emissions. Proposals to sequester carbon dioxide at pressure underground or in the ocean depths are dependent on using compression methods that are efficient and can also overcome problems such as phase change and the material erosion of compressor parts when compressing impure gas mixture. Small changes in compressor efficiency may determine whether carbon sequestration is commercially viable.[0003]Efficient compression requires that as little kinetic energy as possible is imparted to the gas molecules. This implies that a gas packet should move as slowly as possible through the compressor, without sudden accelerations. The direction of motion should preferably be in...

AI Technical Summary

Benefits of technology

[0015]In an embodiment of the invention there is provided a compressor comprising a cylinder and a rotor, whereby the rotor traverses the internal circumference of the cylinder and a pinch point is formed at the closest point of the rotor periphery to the internal wall of the cylinder. The rotor traverses the internal circumference of the cylinder such that the pinch point moves at high, preferably supersonic speed. In an embodiment, the rotor rolls around the internal circumference of the cylinder such that the speed of the rotor surface, relative to the cylinder wall, is low or zero, thus reducing wear and frictional heating of the components and of the gas to be compressed, termed herein “rolling”, thus aiding compressor efficiency. Optionally, a strip valve arrangement on the rotor surface allows entry of gas into the chamber formed between rotor and cylinder. Optionally, a strip valve arrangement on the cylinder wall allows exit of gas from the chamber and optionally incorporates actuation means to control its opening position.

[0021]Embodiments of the invention incorporate rotor surface features in order to increase compressor efficiency.

Problems solved by technology

Gas compression devices used in refrigeration, air conditioning and industry consume a large portion of electrical power generated.

Heat of compression spreading back by leakage or thermal conductance to the intake gas or to less compressed gas in the compression chamber is a cause of inefficiency in compressors requiring additional work energy equal to any increased heat acquired by the gas both before entering and within the compressor.

Because this heat cannot be removed quickly enough, the walls remain hot, heat remains in the gas and the work required rises.

However in piston and cylinder compressors the gas is compressed into a volume defined by unchanging but decreasing surface, therefore there is little possibility of removing the heat of compression during the process.

The higher the rise the greater is the loss of efficiency.

Known types of compressors typically suffer from problems which tend to reduce efficiency, including but not limited to those described herein, namely:impartation of large amounts of kinetic energy to the gas being compressedsudden acceleration of gas leading to high noise levels and energy losseshigh gas flow speeds leading to frictional heating of the gas being compressed, leading to an increased work requirementheat of compression feeding back to the intake charge, leading to an increased work requirementvariable internal surface area leading to a reduced ability to remove heat of compression from the gas being compressedhigh rubbing speeds between internal components leading to wear and frictional losseslow inter-stage compression riselarge physical size relative to gas processing rate

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