Lube oil monitoring system and methods of use thereof

Abstract

An electric motor (168) is driven by modulating an inverter (164) that supplies energy to the motor (168). Clamp modulation is used to produce an output line-to-line voltage, which enable the generation of direct current (DC) or low-frequency alternating current (AC) currents. The clamp modulation generates different combinations of switch states that result in zero output line-to-line voltage, which distributes losses between the switches and diodes differently. The distribution lowers the junction temperatures of the switches and diodes, thereby increasing the inverter's reliability and efficiency. The method can be implemented using either a carrier-based approach, which injects a common mode signal (116) into the modulation signal (120), or a direct switch state vector-based approach, which uses various combinations of switch states in terms of order and time duration.

Claims

<pat:ClaimStatement>-33- Claims< / pat:ClaimStatement> <pat:Claims com:id="claims"> <pat:Claim com:id="CLM-00001"> <pat:ClaimNumber>1< / pat:ClaimNumber> <pat:ClaimText>1. A lube oil cooling system for a gas turbine engine, comprising: a lube oil tank configured to store lube oil; a pump configured to circulate the lube oil from the lube oil tank through the lube oil cooling system; a heat exchanger configured to cool the lube oil; a temperature control valve having: a first inlet port configured to receive the lube oil from the lube oil tank; a second inlet port configured to receive cooled lube oil from the heat exchanger; and an outlet port configured to provide temperature-controlled lube oil to the gas turbine engine; one or more temperature sensors configured to measure at least one of a lube oil tank temperature, a heat exchanger outlet temperature, or a header temperature downstream of the outlet port; and a controller configured to: receive temperature measurements from the one or more temperature sensors; determine a position of the temperature control valve based on the temperature measurements; determine degradation of the temperature control valve by comparing the position of the temperature control valve to an expected position at a given lube oil temperature; and generate a notification when the degradation of the temperature control valve is detected. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00002"> <pat:ClaimNumber>2< / pat:ClaimNumber> <pat:ClaimText>2. The lube oil cooling system of claim 1, wherein the temperature control valve comprises: a valve housing defining internal passages to direct and mix the lube oil from the first inlet port and the cooled lube oil from the second inlet port. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00003"> <pat:ClaimNumber>3< / pat:ClaimNumber> <pat:ClaimText>3. The lube oil cooling system of claim 1, wherein the temperature control valve comprises: a wax element disposed within a valve housing that expands and contracts with temperature changes; and a spring mechanism coupled to the wax element to modulate lube oil flow between the first inlet port and the second inlet port. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00004"> <pat:ClaimNumber>4< / pat:ClaimNumber> <pat:ClaimText>4. The lube oil cooling system of claim 1, wherein the controller is configured to: monitor changes in a lube oil temperature at which the temperature control valve begins opening over time; determine, based on the changes in the lube oil temperature, a rate of change in the lube oil temperature at which the temperature control valve begins opening over time, and predict when the temperature control valve will fail based on the rate of change. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00005"> <pat:ClaimNumber>5< / pat:ClaimNumber> <pat:ClaimText>5. The lube oil cooling system of claim 1, wherein the controller is configured to: determine a characteristic curve representing expected positions of the temperature control valve across a range of temperature differences between the lube oil tank and a heat exchanger outlet; and compare actual positions of the temperature control valve to the characteristic curve to detect deviations, wherein the degradation of the temperature control valve is determined when the deviations exceed predetermined thresholds. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00006"> <pat:ClaimNumber>6< / pat:ClaimNumber> <pat:ClaimText>6. The lube oil cooling system of claim 1, wherein the controller is configured to: determine a bypass flow percentage based on the temperature measurements using; and monitor changes in the bypass flow percentage over time, wherein the degradation of the temperature control valve is determined when the bypass flow percentage deviates from expected values at given operating temperatures. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00007"> <pat:ClaimNumber>7< / pat:ClaimNumber> <pat:ClaimText>7. The lube oil cooling system of claim 1, wherein the controller is configured to generate at least one of heat exchanger degradation alerts indicating cleaning requirements, temperature control valve service recommendations, or alerts indicating fan, belt, or coolant pump failures. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00008"> <pat:ClaimNumber>8< / pat:ClaimNumber> <pat:ClaimText>8. A gas turbine engine system, comprising: a gas turbine engine; a lube oil cooling system comprising: a lube oil tank configured to store lube oil; a pump configured to circulate the lube oil from the lube oil tank through the gas turbine engine system; a heat exchanger configured to cool the lube oil; a temperature control valve configured to: receive lube oil from the lube oil tank and cooled lube oil from the heat exchanger; and provide temperature-controlled lube oil to the gas turbine engine; and one or more temperature sensors configured to measure at least a lube oil tank temperature; and a controller configured to: determine a position of the temperature control valve based on temperature measurements by the one or more temperature sensors; and determine degradation of the temperature control valve by comparing the position of the temperature control valve to an expected position at a given lube oil temperature. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00009"> <pat:ClaimNumber>9< / pat:ClaimNumber> <pat:ClaimText>9. The gas turbine engine system of claim 8, wherein the lube oil cooling system comprises: pipe fittings configured to mechanically couple a first inlet port of the temperature control valve to the lube oil tank and a second inlet port of the temperature control valve to the heat exchanger. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00010"> <pat:ClaimNumber>10< / pat:ClaimNumber> <pat:ClaimText>10. The gas turbine engine system of claim 8, wherein the lube oil cooling system is configured to maintain header temperature below a shutdown threshold by circulating the cooled lube oil through the gas turbine engine. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00011"> <pat:ClaimNumber>11< / pat:ClaimNumber> <pat:ClaimText>11. The gas turbine engine system of claim 8, wherein the controller is configured to: establish baseline temperature control valve operation by monitoring positions of the temperature control valve across operating temperatures; and predict failure of the temperature control valve based on deviations from the baseline temperature control valve operation. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00012"> <pat:ClaimNumber>12< / pat:ClaimNumber> <pat:ClaimText>12. The gas turbine engine system of claim 8, wherein the controller is configured to: monitor a valve opening temperature at which the temperature control valve begins diverting flow of the lube oil to the heat exchanger; and detect when the valve opening temperature increases above a predetermined threshold. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00013"> <pat:ClaimNumber>13< / pat:ClaimNumber> <pat:ClaimText>13. The gas turbine engine system of claim 8, wherein the controller is configured to: analyze impact of seasonal temperature variations on operation of the temperature control valve using an artificial intelligence (AI) system; and generate notifications recommending maintenance of the temperature control valve based on at least one of detected valve degradation, historical seasonal temperature patterns, or predicted failure of the temperature control valve. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00014"> <pat:ClaimNumber>14< / pat:ClaimNumber> <pat:ClaimText>14. The gas turbine engine system of claim 8, wherein the controller is configured to determine the degradation of the temperature control valve based on temperature differentials between lube oil header temperature, heat exchanger outlet temperature, and the lube oil tank temperature. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00015"> <pat:ClaimNumber>15< / pat:ClaimNumber> <pat:ClaimText>15. A method of detecting degradation of a lube oil temperature control valve, comprising: receiving, from one or more temperature sensors, temperature measurements of at least one of a lube oil tank temperature, a heat exchanger outlet temperature, or a header temperature downstream of the temperature control valve; determining, using an artificial intelligence (AI) system, a position of the temperature control valve based on the temperature measurements; determining degradation of the temperature control valve by comparing the position of the temperature control valve to an expected position at a given lube oil temperature; predicting failure of the temperature control valve based on the determined degradation; and generating a notification indicating the predicted failure. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00016"> <pat:ClaimNumber>16< / pat:ClaimNumber> <pat:ClaimText>16. The method of claim 15, comprising: determining a characteristic curve representing expected positions of the temperature control valve across operating temperatures; and comparing the position of the temperature control valve to the characteristic curve. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00017"> <pat:ClaimNumber>17< / pat:ClaimNumber> <pat:ClaimText>17. The method of claim 15, wherein predicting the failure of the temperature control valve comprises at least one of: monitoring a temperature at which the temperature control valve begins diverting flow of the lube oil to the heat exchanger; or detecting when an opening temperature of the temperature control valve increases above approximately 135°F. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00018"> <pat:ClaimNumber>18< / pat:ClaimNumber> <pat:ClaimText>18. The method of claim 15, comprising: extracting, by a feature extraction module, a feature vector from temperature data; and training the AI system based on operational data and detected degradation patterns. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00019"> <pat:ClaimNumber>19< / pat:ClaimNumber> <pat:ClaimText>19. The method of claim 15, comprising detecting degradation of the heat exchanger by: determining a heat rejection value of the heat exchanger based on the position of the temperature control valve; comparing the heat rejection value to an expected heat rejection model. < / pat:ClaimText> < / pat:Claim> <pat:Claim com:id="CLM-00020"> <pat:ClaimNumber>20< / pat:ClaimNumber> <pat:ClaimText>20. The method of claim 15, wherein the degradation of the temperature control valve is determined based on temperature differentials between the header temperature, the heat exchanger outlet temperature, and the lube oil tank temperature. < / pat:ClaimText> < / pat:Claim> < / pat:Claims>