Device for preventing icing in an air conditioning unit for motor vehicles
Method of controlling refrigeration system for automotive air conditioner
Temperature and pressure monitored refrigeration system
Method and apparatus for controlling an electrically driven automotive air conditioner Patent #: 4667480
ApplicationNo. 07/206577 filed on 06/14/1988
US Classes:62/228.3, By refrigerant pressure62/227, By conducted evaporator temperature62/228.5, By variable compressor output, e.g., unloading, staging, etc.62/244Occupant-type vehicle
ExaminersPrimary: Tanner, Harry B.
Attorney, Agent or Firm
International ClassesB60H 1/32 (20060101)
F25D 21/00 (20060101)
F25B 49/02 (20060101)
Foreign Application Priority Data1987-12-10 JP
AbstractAn air-conditioning control system for automotive vehicles, comprising a compressor variable in capacity in accordance with a change in suction pressure thereof. A controller is provided which carries out demisting control, on the basis of output signals from various sensors, in such a manner that, when outdoor-air temperature is equal to or lower than a predetermined value and at the same time the air-conditioning control system is in the indoor-air recirculating mode, the suction pressure set by the controller is lowered to a value at which temperature on the outlet side of an evaporator is brought to a value equal to or lower than a predetermined freezing temperature, and when a state in which freezing of the evaporator may occur has continued for a predetermined period of time, the set suction pressure of the compressor is raised until the temperature on the outlet side of the evaporator is brought to a value equal to or higher than a predetermined non-freezing temperature.
Field of SearchBy refrigerant pressure
By variable speed motor or pulley type mechanism
By variable compressor output, e.g., unloading, staging, etc.
By conducted evaporator temperature
By external cooled gas
TIME OR PROGRAM ACTUATOR
Including time or program actuator
Defrosting or frost inhibiting
Time or program actuator
Time delay of condition sensing or control operation