US 11,852,392 B2
Speed control strategies for a condenser fan in a refrigeration system
Wayne Donnellan, Galway (IE); Premchand Reddy Punuru, Guntur (IN); Michael Greene, Minneapolis, MN (US); and James E Conde, Plymouth, MN (US)
Assigned to THERMO KING LLC, Minneapolis, MN (US)
Filed by THERMO KING LLC, Minneapolis, MN (US)
Filed on Mar. 3, 2021, as Appl. No. 17/191,300.
Claims priority of application No. 20161341 (EP), filed on Mar. 5, 2020.
Prior Publication US 2021/0278115 A1, Sep. 9, 2021
Int. Cl. F25B 49/02 (2006.01); F25B 39/00 (2006.01)
CPC F25B 49/027 (2013.01) [F25B 39/00 (2013.01); F25B 2500/18 (2013.01); F25B 2600/111 (2013.01); F25B 2700/15 (2013.01); F25B 2700/171 (2013.01); F25B 2700/172 (2013.01); F25B 2700/173 (2013.01); F25B 2700/195 (2013.01); F25B 2700/1933 (2013.01); F25B 2700/21162 (2013.01); F25B 2700/21174 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A refrigeration system comprising:
a refrigeration circuit that includes at least a compressor, a condenser, an expansion valve and an evaporator;
a variable-speed condenser fan; and
a controller configured to, in a first mode of operation, monitor a current refrigeration demand of the refrigeration system and to set a speed of the condenser fan based on the current refrigeration demand of the refrigeration system,
wherein the controller is configured to:
monitor a set of current operating parameters of the refrigeration circuit that is indicative of the current refrigeration demand; and
set the condenser fan speed based on the set of current operating parameters,
wherein the controller is configured to set the speed of the condenser fan based on a predetermined model of system efficiency, which is a function of the set of current operating parameters and condenser fan speed,
wherein:
the controller is configured to set the speed of the condenser fan based on a predetermined relationship between the set of current operating parameters and a condenser fan speed at which system efficiency will be at its maximum for the set of current operating parameters; and
the predetermined relationship has been determined by performing a regression analysis using the predetermined model, and
wherein:
the predetermined relationship is in the form of a regression model, which is stored in a memory that is accessible by the controller; and
the controller is configured to:
input the set of current operating parameters into the regression model;
receive, as an output from the regression model, the condenser fan speed at which the system efficiency will be at its maximum for the set of current operating parameters; and
set the condenser fan to operate at a speed that is selected based on the condenser fan speed at which the system efficiency will be at its maximum for the set of current operating parameters.