Low refrigerant charge detection especially for automotive air conditioning systems
First Claim
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1. 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.
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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.
100 Citations
9 Claims
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1. 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:
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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. - View Dependent Claims (2)
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3. An improved vehicle air conditioning system having a compressor, expansion valve, evaporator and condenser, wherein the improvement comprises:
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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.
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4. An improved vehicle air conditioning system having a compressor, expansion valve, evaporator and condenser, wherein the improvement comprises:
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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.
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5. An improved vehicle air conditioning system having a compressor, expansion valve, evaporator and condenser, wherein the improvement comprises:
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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. - View Dependent Claims (6)
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7. 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:
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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.
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8. 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:
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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. - View Dependent Claims (9)
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Specification