Isothermal power

Abstract

This invention provides means for producing power by using isothermal compressors and isothermal expanders. One embodiment has an isothermal compressor that compresses air (or other gas), passes the air through a counter-flow heat exchanger, which heats the air, uses the heated air to drive an isothermal expander for power generation, and transfers the expander exhaust back through the counter-flow heat exchanger to heat the input air to the expander. Another embodiment has a boiler that produces vapor that flows through a counter-flow heat exchanger to superheat the vapor. The vapor then flows through an isothermal expander for power generation. The exhaust from the isothermal expander flows back through the counter-flow heat exchanger to supply heat to the vapor coming from the boiler and then flows through another heat exchanger that preheats the feed liquid flowing to the boiler.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This claims priority to and the benefit of Provisional U.S. Patent Application Ser. No. 60 / 914,036, filed Apr. 26, 2007, the entirety of which is hereby incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]Most of the heat engines in use today use adiabatic expansion of gases to produce power. The Rankine, Brayton, Otto cycles, and others use adiabatic expansions, and some of them also use adiabatic compressions. This disclosure shows that isothermal expansion and compression have some important efficiency advantages.[0003]The isothermal cycle can use a working fluid such as water, ammonia, or propylene that are boiled and then expanded isothermally in an engine to produce power. The vapors are then condensed back to a liquid to repeat the cycle. It can also use a gas such as air or helium that can be compressed isothermally, heated, and then expanded isothermally in an engine that drives an electric generator or drives some o...

AI Technical Summary

Benefits of technology

[0007]Another important feature of the isothermal engine is that the same amount of gas can be expanded to much larger volumes than the adiabatic machine, and this provides more output energy.

[0015]Using a system that has isothermal compression and expansion of single-phase gases provides performances that are even better than isothermal system of the two-phase fluids, such as water-steam (Rankine cycle). Air can be used as the working fluid. Helium has high heat transfer properties and might be used. It is used in Stirling engines.

[0018]It is therefore an object of the present invention to provide an economical means of producing power using isothermal compressors and isothermal expanders.

[0024]It is another object of the present invention to provide means for reducing mechanical losses in the compression and expansion devices.

[0025]It is another object of the present invention to provide methods to effectively produce approximate isothermal compression and expansion of gases.

Problems solved by technology

This cannot be done with an adiabatic expander, because the vapor exhaust from the adiabatic expander is normally cooler than the superheat temperature.

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