Organic rankine cycle system and method

Abstract

An ORC system configured to limit temperature of a working fluid below a threshold temperature is provided. The ORC system includes a heat source configured to provide waste heat fluid. The ORC system also includes a heat exchanger coupled to the heat source, wherein the heat exchanger includes multiple external or internal enhancement features. The external enhancement features are configured to reduce a first heat transfer coefficient between the working fluid and the waste heat fluid from the heat source, external to the heat exchanger. The internal enhancement features are configured to increase a second heat transfer coefficient between the working fluid and the waste heat fluid from a heat source, internal to the heat exchanger.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is related to the following co-pending U.S. patent application Ser. No. {Attorney Docket No. 233702-1}, entitled “Organic Rankine Cycle System and Method” assigned to the same assignee as this application and filed herewith, the entirety of which is incorporated by reference herein.BACKGROUND[0002]The invention relates generally to organic rankine cycle (ORC) systems, and more particularly to an economical system and method for the same.[0003]With the advent of the energy crisis and, the need to conserve, and to more effectively use, our available energies, rankine cycle systems have been used to capture the so called “waste heat”, that was otherwise being lost to the atmosphere and, as such, was indirectly detrimental to the environment by requiring more fuel for power production than necessary.[0004]Common sources of waste heat that are presently being discharged to the environment are geothermal sources and heat from o...

AI Technical Summary

Benefits of technology

[0007]Therefore, an improved ORC system is desirable to address one or more of the aforementioned issues.

[0008]In accordance with an embodiment of the invention, an ORC system configured to limit temperature of a working fluid below a threshold temperature is provided. The ORC system includes a heat source configured to provide waste heat fluid. The ORC system also includes a heat exchanger coupled to the heat source, wherein the heat exchanger includes multiple external or internal enhancement features. The external enhancement features are configured to reduce a first heat transfer coefficient between the working fluid and the waste heat fluid from the heat source, external to the heat exchanger. The internal enhancement features are configured to increase a second heat transfer coefficient between the working fluid and the waste heat fluid from a heat

Problems solved by technology

With the advent of the energy crisis and, the need to conserve, and to more effectively use, our available energies, rankine cycle systems have been used to capture the so called “waste heat”, that was otherwise being lost to the atmosphere and, as such, was indirectly detrimental to the environment by requiring more fuel for power production than necessary.

However, the working fluid may degrade beyond a critical temperature, such as, but not limited to, 500 deg C. In a gas turbine system, the temperature of the exhaust is comparable to such high temperatures and hence, there is a reasonable probability of degradation of the working fluid due to direct exposure to the hot gas from the exhaust.

However, the intermediate fluid thermal represents up to about one-quarter of the cost of the complete ORC.

Furthermore, the intermediate fluid system and heat exchangers require a higher temperature difference resulting in increase in size and lowering overall efficiency.

Images