US 12,241,432 B2
Multifuel closed-loop thermal cycle piston engine, system and method
Ralph T. Worthington, Spring Valley, CA (US)
Assigned to Engine Development Corp, LLC, Spring Valley, CA (US)
Appl. No. 18/576,285
Filed by Engine Development Corp, LLC, Spring Valley, CA (US)
PCT Filed Jul. 14, 2022, PCT No. PCT/US2022/037158
§ 371(c)(1), (2) Date Jan. 3, 2024,
PCT Pub. No. WO2023/003753, PCT Pub. Date Jan. 26, 2023.
Claims priority of provisional application 63/224,104, filed on Jul. 21, 2021.
Prior Publication US 2024/0151193 A1, May 9, 2024
Int. Cl. F02G 3/02 (2006.01); F02D 41/04 (2006.01); F02D 41/40 (2006.01); F02D 41/00 (2006.01)
CPC F02G 3/02 (2013.01) [F02D 41/045 (2013.01); F02D 41/401 (2013.01); F02D 2041/001 (2013.01); F02G 2254/10 (2013.01); F02G 2270/90 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A multifuel closed-loop thermal cycle piston engine comprising:
an externally-fired continuous combustion chamber configured to conduct continuous combustion of a fuel in a fuel burner chamber, the externally-fired continuous combustion chamber comprising a water injection stage succeeding the fuel burner chamber, the water injection stage configured to inject water into the externally-fired continuous combustion chamber post-combustion;
a drive stage coupled to an engine exhaust manifold and comprising at least one drive cylinder;
a compression stage distinct from the drive stage, the compression stage comprising at least one compression cylinder, and a pressure-operated exhaust valve of the at least one compression cylinder wherein the pressure-operated exhaust valve pumps air to the fuel burner chamber and comprises a variable pressure spring configured to provide minimum pressure to open the pressure-operated exhaust valve and maximum pressure to return a valve plug of the pressure-operated exhaust valve to a valve seat during higher RPM operation; and
wherein a quantity of water injected into the externally-fired continuous combustion chamber post-combustion is configured to maintain an engine exhaust exiting to the engine exhaust manifold at or below a temperature set point.