Closed loop thermodynamic machine

Abstract

According to a first aspect of the invention there is provided a thermodynamic machine operating according to the Brayton cycle and including a closed loop fluid circuit for circulating working fluid. A fluid compressor (8) and a fluid expander (10) are independently controllable variable positive displacement machines. The variable positive displacement machines incorporate working chambers of cyclically varying volume, the net fluid displacement of each working chamber being selectable on a cycle by cycle basis. The compressor and expander axles are linked and the compressor and expander can be controlled to independently vary the displacement of the compressor, the displacement of the expander and the net torque exerted on the axle. The machine works efficiently with a wide range of heat source and heat sink temperatures and can respond to varying power demands, including transient changes to power demand.

Dependencies are inferred from the claim text.