US 12,264,855 B2
Cascade heat pump and method for heating or cooling a coolant by means of a cascade heat pump
Christian Schneck, Braunschweig (DE); and Juergen Olfe, Volkse (DE)
Assigned to Volkswagen Aktiengesellschaft, Wolfsburg (DE)
Filed by Volkswagen Aktiengesellschaft, Wolfsburg (DE)
Filed on Dec. 8, 2022, as Appl. No. 18/077,735.
Claims priority of application No. 10 2021 214 258.3 (DE), filed on Dec. 13, 2021.
Prior Publication US 2023/0184468 A1, Jun. 15, 2023
Int. Cl. F25B 30/00 (2006.01); F25B 41/40 (2021.01)
CPC F25B 30/00 (2013.01) [F25B 41/40 (2021.01); F25B 2321/001 (2013.01); F25B 2321/002 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A cascade heat pump comprising n stages where n≥2, each of the n stages comprising:
a heat pump with a coolant inlet, a first coolant outlet and a second coolant outlet,
wherein the heat pump has a hot side and a cold side and a flow divider,
wherein the flow divider divides a coolant flow entering the coolant inlet into partial flows between the hot side and the cold side,
wherein the first coolant outlet of the heat pump of each stage i, where i=1 . . . n−1, is connected to the coolant inlet of the heat pump of a subsequent stage i+1, such that a first partial flow of the coolant is provided from the first coolant outlet of the heat pump of each stage i, where i=1 . . . n−1, to the coolant inlet of the heat pump of the subsequent stage i+1, and
wherein the second coolant outlet of the heat pump of at least one subsequent stage i+1, where i=1 . . . n−1, is connected via a recirculation line to the coolant inlet of the heat pump of a preceding stage 1 . . . i, such that a second partial flow of the coolant is fed from the second coolant outlet of the heat pump of the at least one subsequent stage i+1, where i=1 . . . n−1, to the coolant inlet of the heat pump of the preceding stage 1 . . . i.