US 12,438,432 B2
Low temperature magnetohydrodynamics power system
Lijun Wu, Kanata (CA); Philip Geddis, Ottawa (CA); Steven Chen, Nepean (CA); Andrew McDonald, Ottawa (CA); Alex McCready, Sittsville (CA); and Bruce Clements, Nepean (CA)
Assigned to HER MAJESTY THE QUEEN IN RIGHT OF CANADA AS REPRESENTED BY THE MINISTER OF NATURAL RESOURCES, Ottawa (CA)
Appl. No. 18/550,151
Filed by Her Majesty The Queen In Right of Canada as Represented by the Minister of Natural Resources, Ottawa (CA)
PCT Filed Mar. 11, 2022, PCT No. PCT/CA2022/050366
§ 371(c)(1), (2) Date Sep. 12, 2023,
PCT Pub. No. WO2022/187971, PCT Pub. Date Sep. 15, 2022.
Claims priority of provisional application 63/160,257, filed on Mar. 12, 2021.
Prior Publication US 2024/0171055 A1, May 23, 2024
Int. Cl. H02K 44/08 (2006.01); F01K 21/00 (2006.01); F01K 25/06 (2006.01); F01K 27/00 (2006.01); F03G 4/00 (2006.01)
CPC H02K 44/08 (2013.01) [F01K 21/005 (2013.01); F01K 25/06 (2013.01); F01K 25/065 (2013.01); F01K 27/00 (2013.01); F03G 4/001 (2021.08); F03G 4/037 (2021.08); H02K 44/085 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A system for converting a low-temperature heat source into power, comprising:
a vertically positioned closed-looped liquid metal circuit for containing and circulating a liquid metal,
a vertically positioned closed-looped refrigerant circuit for containing and circulating a refrigerant,
the liquid metal circuit and the refrigerant circuit interacting with each other through a mixer, a riser and a separator shared by the liquid metal circuit and the refrigerant circuit,
a closed-looped heat sink circuit interacting with the refrigerant circuit through a condenser shared by the heat sink circuit and the refrigerant circuit,
a closed-looped heat source circuit interacting with the liquid metal circuit through a heat exchanger shared by the heat source circuit and the liquid metal circuit, and
a pressure controller,
wherein:
heat is transferred from the low-temperature heat source to the liquid metal circulating in the liquid metal circuit through the heat exchanger to provide a heated liquid metal,
the refrigerant circulating in the refrigerant circuit is heated into vapor form by the heated liquid metal that enters the mixer, the liquid metal and the refrigerant in vapor form producing a two-phase mixture,
the two-phase mixture is flown up the riser and into the separator to be separated,
wherein:
the refrigerant in vapor form, after being separated from the liquid metal in the separator, is entered through:
a recuperator, wherein heat is released from the refrigerant in vapor form to liquid refrigerant,
the condenser, wherein the refrigerant is further cooled down by passing through a coolant from a heat sink to release heat to the heat sink and change the refrigerant in vapor form into the liquid refrigerant,
a liquid pump, the liquid pump driving flow of the liquid refrigerant,
the recuperator, wherein the liquid refrigerant is preheated by the refrigerant in vapor form, and
the mixer, wherein the liquid refrigerant upon mixing with the heated liquid metal entering the mixer changes from the liquid refrigerant into the refrigerant in vapor form, and
wherein:
the liquid metal, after being separated from the refrigerant in the separator, is entered through:
a magnetohydrodynamic generator through a downcomer, wherein kinetic energy of the liquid metal is converted into electricity by the magnetohydrodynamic generator,
the heat exchanger, wherein the heat is transferred from the low-temperature heat source to the liquid metal circulating the liquid metal circuit to provide the heated liquid metal, and
wherein speed of the liquid pump is controlled by the pressure controller and flowrate of the liquid refrigerant according to an adjustable pressure in the condenser following a changing temperature of the heat sink to vary condensing temperature in the condenser.