Method and apparatus for energy harvesting through phase-change induced pressure rise under cooling conditions
View Patent ↗A method and apparatus for generating power which includes a phase-change media (PCM) that expands upon cooling contained within an expandable capsule if the phase change involves solidification (if phase change is solid-solid, then capsules are not needed), a carrier liquid that does not freeze in the operating temperature range, a heat exchanger, and an engine. Alternatively, the method and apparatus can include a PCM contained within a layer next to the walls of a constant volume container, a working liquid within the container that does not freeze in the operating temperature range, a heat exchanger, and an engine. In both cases, the engine denotes a device that converts the energy in the high-pressure liquid into electrical or mechanical power.
1. An apparatus for harvesting energy and generating power, the apparatus comprising:
a working media comprising a phase-change media contained within expandable capsules and a carrier media that does not change phase in an operating temperature range;
wherein the phase-change media expands upon cooling to create pressure in the working media;
a heat exchanger;
a separator;
a mixer;
a recirculating pump;
a pressurizer; and
a power harvesting device.
2. The apparatus of claim 1 wherein the phase-change media contained within expandable capsules are dispersed throughout the carrier media.
3. The apparatus of claim 1 wherein the phase-change media undergoes phase change non-uniformly,
4. The apparatus of claim 1 wherein energy is harvested from the pressure rise in the working media induced by transformation of the phase-change media mixed with the carrier media.