Utility scale method and apparatus to convert low temperature thermal energy to electricity

• US 20060213502A1
• Filed: 03/23/2006
• Published: 09/28/2006
• Est. Priority Date: 03/23/2005
• Status: Active Grant

• Current Assignee: PDM Solar, Inc.
• Original Assignee: PDM Solar, Inc.
• Inventors: Baker, David M.
• Granted Patent: US 7,748,219 B2
• Time in Patent Office: Days
• US Class Current: 126/568
• CPC Class Codes: F03G 6/02 using a single state working fluid
• CPC Class Codes: F03G 7/04 using pressure differences or thermal differences occurring in nature F03G7/06 takes precedence
• CPC Class Codes: F24S 10/72 the tubular conduits being integrated in a block; the tubular conduits touching each other
• CPC Class Codes: F24S 80/30 Arrangements for connecting the fluid circuits of solar collectors with each other or with other components, e.g. pipe connections; Fluid distributing means, e.g. headers
• CPC Class Codes: F24S 90/00 Solar heat systems not otherwise provided for
• CPC Class Codes: F28D 20/0034 using liquid heat storage material
• CPC Class Codes: Y02E 10/46 Conversion of thermal power into mechanical power, e.g. Rankine, Stirling or solar thermal engines
• CPC Class Codes: Y02E 60/14 Thermal energy storage
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors

Abstract

Methods and systems are disclosed to convert low temperature thermal energy to electricity. An example apparatus disclosed herein includes an electrical generating unit to receive heat energy to produce electricity, a concentrator including a heat engine, a liquid piston operatively coupled to the heat engine, and a heat pump operatively coupled to the liquid piston, the heat engine adapted to collect thermal energy, and the heat pump operatively coupled to the electrical generating unit to provide heat to the electrical generating unit. The example apparatus disclosed herein also includes a heat engine floating piston disposed in the heat engine, a heat pump floating piston disposed in the heat pump, and wherein the heat engine floating piston and the heat pump floating piston oscillate.

Claims

1. A thermal energy to electricity system comprising:

an electrical generating unit to receive heat energy to produce electricity;

a concentrator comprising a heat engine, a liquid piston operatively coupled to the heat engine, and a heat pump operatively coupled to the liquid piston, the heat engine adapted to collect thermal energy, and the heat pump operatively coupled to the electrical generating unit to provide heat to the electrical generating unit;

a heat engine floating piston disposed in the heat engine,

a heat pump floating piston disposed in the heat pump; and

wherein the heat engine floating piston and the heat pump floating piston oscillate.

2. A thermal energy system as defined in claim 1 further comprising a controller to invoke the oscillation of the heat engine floating piston and the heat pump floating piston.

3. A thermal energy system as defined in claim 1 wherein the concentrator collects one of a solar energy, geothermal energy, or industrial waste energy.

4. A thermal energy system as defined in claim 1 wherein the electrical generating unit comprises a steam turbine.

5. A thermal energy system as defined in claim 1 wherein the concentrator is a closed system, the closed system further comprising a heat engine expansion chamber and a heat pump expansion chamber.

6. A thermal energy system as defined in claim 5 wherein the heat engine expansion chamber is operatively connected to the thermal energy source via at least one of a pump or a heat engine inlet valve.

7. A thermal energy system as defined in claim 6 further comprising a heat exchanger operatively connected to a cold thermal storage device and a heat exchanger chamber operatively connected to a hot thermal storage device.

8. A thermal energy system as defined in claim 6 wherein the heat pump expansion chamber is operatively connected to the electrical generating unit via at least one of a heat pump pressure valve or a heat pump vacuum valve.

9. A thermal energy system as defined in claim 1 further comprising at least one of a plurality of sensors or transducers to determine a position for at least one of the heat engine floating piston or the heat pump floating piston, the at least one of the plurality of sensors or transducers further detecting a temperature, a pressure, or a volume for at least one of the heat engine or the heat pump.

10. A thermal energy system as defined in claim 1 wherein the heat engine floating piston and the heat pump floating piston oscillate near a resonant frequency.

11. A method of converting thermal energy to electricity comprising:

collecting thermal energy;

transferring the collected thermal energy to a concentrator, the concentrator comprising a heat engine, a liquid piston, and a heat pump; and

invoking an oscillating cycle of the heat engine, the liquid piston, and the heat pump to drive an electrical generating unit operatively connected to the heat pump.

12. A method as defined in claim 11 wherein invoking the oscillating cycle of the heat engine further comprises controlling a heat engine piston through at least one of an isothermal expansion phase, an isentropic expansion phase, a constant volume compression phase, an isothermal compression phase, or an isentropic compression phase.

13. A method as defined in claim 12 wherein the isentropic expansion phase further comprises maintaining at least one of the heat engine piston or walls of the concentrator at a temperature to prevent liquid condensation.

14. A method as defined in claim 11 wherein invoking the oscillating cycle of the heat pump further comprises controlling a heat pump piston through at least one of an isentropic compression phase, an isothermal compression phase, an isentropic expansion phase, or an isothermal expansion phase.

15. A method as defined in claim 14 wherein the electrical generating unit is driven by a heat pump fluid during at least one of the isothermal compression phase or the isothermal expansion phase.

16. A method as defined in claim 11 wherein the oscillating cycle of the heat engine comprises a heat engine piston to ascend and descend, and the oscillating cycle of the heat pump further comprises a heat pump piston to at least one of descend in response to the heat engine piston ascension and ascend in response to the heat engine piston descension.

17. A method as defined in claim 11 wherein the oscillating cycle operates near a resonant frequency.

18. An article of manufacture storing machine readable instructions which, when executed, cause a machine to:

collect thermal energy;

transfer the collected thermal energy to a concentrator, the concentrator comprising a heat engine, a liquid piston, and a heat pump; and

invoke an oscillating cycle of the heat engine, the liquid piston, and the heat pump to drive an electrical generating unit operatively connected to the heat pump.

19. An article of manufacture as defined in claim 18 wherein the machine readable instructions cause the machine to control a heat engine piston through at least one of an isothermal expansion phase, an isentropic expansion phase, a constant volume compression phase, an isothermal compression phase, or an isentropic compression phase.

20. An article of manufacture as defined in claim 19 wherein the machine readable instructions cause the machine to maintain at least one of the heat engine piston or walls of the concentrator at a temperature to prevent liquid condensation during the isentropic expansion phase.

21. An article of manufacture as defined in claim 18 wherein the machine readable instructions cause the machine to control a heat pump piston through at least one of an isentropic compression phase, an isothermal compression phase, an isentropic expansion phase, or an isothermal expansion phase.

22. An article of manufacture as defined in claim 21 wherein the machine readable instructions cause the machine to drive the electrical generating unit with a heat pump fluid during at least one of the isothermal compression phase or the isothermal expansion phase.

23. An article of manufacture as defined in claim 18 wherein the machine readable instructions cause the machine to control a heat engine piston during the oscillating cycle of the heat engine, the heat engine piston ascending and descending, the oscillating cycle of the heat pump further comprising a heat pump piston to at least one of descend in response to the heat engine piston ascension and ascend in response to the heat engine piston descension.

24. An article of manufacture as defined in claim 18 wherein the machine readable instructions cause the machine to oscillate near a resonant frequency.