Low refrigerant charge detection especially for automotive air conditioning systems
AssigneeGeneral Motors Corporation
InventorsEdwin J. Stanke, David L. Montgomery
Life of this patent
Estimating the term…
Abstract
A vehicle air conditioning system has means for measuring a first physical quantity related to air conditioning system load to produce a first signal and means for measuring a second physical quantity related to air conditioning system cooling capacity to produce a second signal. Said first and second signals are used to calculate a predicted refrigerant charge for detection of, and protection from, an inadequate refrigerant charge.
Claims9
In a vehicle air conditioning system having a compressor, expansion valve, evaporator and condenser, a method of preventing compressor damage due to a low refrigerant charge, said method comprising:
- measuring ambient air temperature to produce a load signal;
- measuring evaporator temperature and vehicle speed to produce respective first and second capacity signals corresponding thereto;
- predicting said refrigerant charge from said load signal and said first and second capacity signals;
- and
- disabling said compressor when said predicted refrigerant charge is below a predetermined level.
An improved vehicle air conditioning system having a compressor, expansion valve, evaporator and condenser, wherein the improvement comprises:
- means for measuring ambient air temperature to produce a load signal;
- means for measuring evaporator temperature and vehicle speed to produce respective first and second capacity signals corresponding thereto;
- means for predicting said refrigerant charge from said load signal and said first and second capacity signals;
- and
- means for disabling said compressor when said predicted refrigerant charge is below a predetermined level.
An improved vehicle air conditioning system having a compressor, expansion valve, evaporator and condenser, wherein the improvement comprises:
- means for measuring ambient air temperature to produce a load signal;
- means for measuring evaporator temperature to produce a first capacity signal;
- means for measuring a quantity related to one of a) compressor speed and b) condenser air flow to produce a second capacity signal;
- means for predicting said refrigerant charge from said load signal and said first and second capacity signals;
- and
- means for disabling said compressor when sad predicted refrigerant charge is below a predetermined level.
An improved vehicle air conditioning system having a compressor, expansion valve, evaporator and condenser, wherein the improvement comprises:
- means for measuring ambient air temperature to produce a load signal;
- means for measuring a quantity related to evaporator temperature to produce a first capacity signal
- means for measuring a quantity related to compressor speed to produce a second capacity signal;
- means for measuring condenser air flow to produce a third capacity signal;
- means for predicting said refrigerant charge from said load signal and said first, second and third capacity signals;
- and
- means for disabling said compressor when said predicted refrigerant charge is below a predetermined level.
In a vehicle air conditioning system having a compressor, expansion valve, evaporator and condenser, a method of preventing compressor damage due to a low refrigerant charge, said method comprising:
- measuring ambient air temperature to produce a load signal;
- measuring evaporator temperature to produce a first capacity signal;
- measuring a quantity related to one of a) compressor speed and b) condenser air flow to produce a second capacity signal;
- predicting said refrigerant charge from said load signal and said first and second capacity signals;
- and
- disabling said compressor when said predicted refrigerant charge is below a predetermined level.
In a vehicle air conditioning system having a compressor, expansion valve, evaporator and condenser, a method of preventing compressor damage due to a low refrigerant charge, said method comprising:
- measuring ambient air temperature to produce a load signal;
- measuring a quantity related to evaporator temperature to produce a first capacity signal;
- measuring a quantity related to compressor speed to produce a second capacity signal;
- measuring condenser air flow to produce a third capacity signal;
- predicting said refrigerant charge from said load signal and said first, second and third capacity signals;
- and
- disabling said compressor when said predicted refrigerant charge is below a predetermined level.
Dependencies are inferred from the claim text.