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US 6,050,098 AGranted
Use of electronic expansion valve to maintain minimum oil flow
AssigneeAmerican Standard Inc.
InventorsJonathan M. Meyer, Lee L. Sibik
Life of this patent
Estimating the term…
Abstract
A method of controlling an expansion valve including the steps of: measuring a primary system condition; determining an error in the primary system condition; measuring a secondary system condition; determining an error in the secondary system condition; and modulating the expansion valve based upon the larger of the first or second error.
Claims8
A method of controlling an expansion valve to maintain differential pressure in an HVAC system comprising the steps of:
- measuring a primary system condition;
- determining a first error in the primary system condition wherein the first error is a measure of refrigerant liquid level;
- measuring a secondary system condition;
- determining a second error in the secondary system condition wherein the second error is a measure of the pressure differential across a compressor;
- and
- modulating the expansion valve based upon the smaller of the first or second error.
3 more elements
A method of controlling an expansion valve including the steps of:
- measuring a refrigerant liquid level;
- comparing the measured refrigerant liquid level with a desired refrigerant liquid level to establish a refrigerant level error;
- measuring a system pressure differential;
- comparing the measured system pressure differential with a desired system pressure differential to determine a system differential pressure error;
- comparing the liquid level error to the differential pressure error to determine the smaller error;
- and
- modulating the expansion valve to control the smaller error.
4 more elements
Dependencies are inferred from the claim text.