Dual thermochromic liquid crystal temperature sensing for refrigerant charge indication
First Claim
1. A method of determining the sufficiency of refrigerant charge in a refrigeration system having a compressor, a condenser, an expansion device and an evaporator fluidly connected in serial refrigerant flow relationship comprising the steps of:
- sensing the temperature of the liquid refrigerant leaving the condenser;
sensing a second temperature which, if said liquid refrigerant temperature is subtracted therefrom, will provide an indication of the refrigerant charge sufficiency in the system; and
visually displaying by way of thermochromic strips both said sensed liquid refrigerant temperature and said sensed second temperature such that the respective position of each display is representative of its value, and the relative positions of the sensed temperature displays are indicative of refrigerant charge sufficiency in the system.
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Accused Products
Abstract
The sufficiency of refrigerant charge in an air conditioning system is determined by a comparison of two sensed temperatures in the system, one being the liquid line temperature and the other being either the outdoor temperature or the condenser coil temperature. In one embodiment the two sensed temperatures are displayed on respective thermochromic strips which are so calibrated and juxtaposed as to provide a visual indication, by the relative positions of the two displayed sensed temperatures, as to whether the refrigerant charge is adequate. In another embodiment, the sensed liquid line temperature is displayed by way of a plurality of LEDs and the other temperature is displayed by way of a marker on a temperature scale. If the two displayed temperatures are aligned, then the refrigerant charge is optimized, and if they are not aligned, the system is undercharged or overcharged.
97 Citations
16 Claims
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1. A method of determining the sufficiency of refrigerant charge in a refrigeration system having a compressor, a condenser, an expansion device and an evaporator fluidly connected in serial refrigerant flow relationship comprising the steps of:
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sensing the temperature of the liquid refrigerant leaving the condenser;
sensing a second temperature which, if said liquid refrigerant temperature is subtracted therefrom, will provide an indication of the refrigerant charge sufficiency in the system; and
visually displaying by way of thermochromic strips both said sensed liquid refrigerant temperature and said sensed second temperature such that the respective position of each display is representative of its value, and the relative positions of the sensed temperature displays are indicative of refrigerant charge sufficiency in the system. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. Apparatus for indicating the sufficiency of refrigerant charge in a refrigeration system having a compressor, a condenser, an expansion device and an evaporator fluidly connected in serial refrigerant flow relationship comprising:
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a first sensor for sensing the temperature of the liquid refrigerant leaving the condenser;
a second sensor for sensing a related temperature which, when the liquid refrigerant temperature is subtracted therefrom, will provide an indication of the adequacy of refrigerant charge in the system;
a first visual display to provide an indication of the sensed liquid refrigerant temperature; and
a second visual display to provide a visual indication of the temperature sensed by said second sensor;
wherein at least one of said first or second visual displays is by way of a thermochromic strip and the relative position of the respective temperature indicators are indicative of the charge sufficiency in the system. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification