US 12,455,101 B2
Method for operating a heat pump for a motor vehicle and heat pump
Jochen Westhaeuser, Braunschweig (DE); Sven Twenhoevel, Sassenburg (DE); and Peter Hellmann, Cremlingen (DE)
Assigned to Volkswagen Aktiengesellschaft, Wolfsburg (DE)
Filed by Volkswagen Aktiengesellschaft, Wolfsburg (DE)
Filed on Nov. 1, 2022, as Appl. No. 17/978,773.
Claims priority of application No. 10 2021 212 314.7 (DE), filed on Nov. 2, 2021.
Prior Publication US 2023/0138734 A1, May 4, 2023
Int. Cl. F25B 47/02 (2006.01); B60H 1/00 (2006.01); F25B 13/00 (2006.01); F25B 30/02 (2006.01)
CPC F25B 47/025 (2013.01) [B60H 1/00878 (2013.01); F25B 13/00 (2013.01); F25B 30/02 (2013.01); B60H 2001/00949 (2013.01); F25B 2700/1933 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method for operating a heat pump of a motor vehicle, the heat pump comprising a refrigerant circuit with a refrigerant, the heat pump comprising an ambient heat exchanger, a compressor, a heating heat exchanger, and a throttle, the method comprising:
determining an expected start time of a charging process of a motor vehicle battery;
determining a maximum dew point undershoot and/or a maximum frost mass;
operating the heat pump such that the previously determined maximum dew point undershoot and/or the maximum frost mass are reached within a predefined time period before the expected start time; and
initiating, a defrosting process, during a battery charging process, upon reaching the maximum dew point undershoot and/or upon reaching the maximum frost mass,
wherein said determining the expected start time of the charging process takes into account a state of charge of the battery, a range of the motor vehicle and an expected vehicle operating time,
wherein the defrosting continues until a surface temperature of an ambient heat exchanger of the motor vehicle is above 0° C. to ensure that water drains during the charging period,
wherein the defrosting continues beyond a time when an ambient heat exchanger of the motor vehicle is free of frost and ice, and
wherein the maximum dew point undershoot and/or the maximum frost mass are dynamically adjusted.