Energy conversion system

Abstract

An efficient split cycle solar energy conversion system utilizes sensible heat storage to isolate a solar receiver loop from a Brayton cycle engine loop. In this system a sensible heat storage unit is first charged by the solar receiver, is then switched to the inlet to the Brayton cycle turbine where it is discharged, and finally may be utilized as a high temperature, high effectiveness recuperator to recapture waste heat from the Brayton cycle turbine. With high effectiveness sensible heat storage recuperation, the Brayton cycle engine runs at extremely high efficiency. Moreover, since these storage devices can be run efficiently at low gas velocity, and since recuperated Brayton cycle engines become very efficient at extremely low pressure ratios, an overall thermal/electric conversion efficiency in excess of 60% can be obtained. Further, the Brayton cycle engine can be used with a sensible heat storage unit charged from a fuel fired source utilizing so-called 'dirty' fuels, because fuel by-products which would ordinarily corrode the turbine blades of the Brayton cycle engine are either not picked up in the low velocity discharge of the storage unit or impinge on the blades at velocities low enough so that no damage is done to the blades.