Patent ID: 8833101
Filing Date: 2014-09-16
Classification: F25B

Abstract:
1. Apparatus for use as a heat pump comprising: a compression chamber; an inlet for allowing gas to enter the compression chamber; a compression piston stage comprising a compression piston for compressing gas contained in the compression chamber; a heat exchanger for receiving thermal energy from gas compressed by the compression piston; an expansion chamber for receiving gas after exposure to the heat exchanger; an expansion piston stage comprising an expansion piston for expanding gas received in the expansion chamber; and an exhaust for venting gas from the expansion chamber after expansion thereof; wherein the expansion piston is moveable between a first position and a second position, with expansion of gas contained in the expansion chamber occurring as the gas does work to help move the expansion piston from the first position to the second position; and wherein the expansion piston comprises an expansion piston aperture located on a working face of the expansion piston and having an expansion valve for allowing gas to pass through the expansion piston.