Model-based method and system to detect heat exchanger fouling

An environmental control system (ECS) for a vehicle, the ECS comprising:

• a gas turbine engine operable to provide power to the vehicle and to provide pressurized air for use in a passenger cabin;
• an air duct that includes an inlet and an exhaust configured to pass air from the atmosphere therethrough;
• a first heat exchanger arranged in the air duct, wherein the first heat exchanger comprises a first heat exchanger inlet and a first heat exchanger outlet, the first heat exchanger inlet configured to receive pressurized air from the gas turbine engine;
• a second heat exchanger arranged in the air duct, wherein the second heat exchanger comprises a second heat exchanger inlet and a second heat exchanger outlet, the second heat exchanger inlet configured to receive air from the first heat exchanger outlet;
• a first temperature sensor operable to measure a first air temperature, the first temperature sensor arranged in the air duct between the inlet and the first and second heat exchangers;
• a second temperature sensor operable to measure a second air temperature, the second temperature sensor arranged in the air duct between the first and second heat exchangers and the exhaust;
• a third temperature sensor operable to measure a third air temperature, the third temperature sensor arranged in the first heat exchanger outlet of the first heat exchanger;
• a fourth temperature sensor operable to measure a fourth air temperature, the fourth temperature sensor arranged in the second heat exchanger outlet of the second heat exchanger;
• and
• a controller comprising:
• a computer memory operable to store:
• a heat exchanger fouling model;
• and
• received values for the measured first air temperature, second air temperature, third air temperature, and fourth air temperature;
• and
• a computer processor operable to:
• calculate a first heat exchanger fouling indication and a second heat exchange fouling indication, based on the heat exchanger fouling model;
• and
• output a first alert upon at least one of the first heat exchanger fouling indication and the second heat exchanger fouling indication exceeding a heat exchanger fouling threshold.

A system, comprising:

• a data input operable to receive:
• past instances of temperature measurements for a fleet of vehicles, the temperature measurements comprising:
• a first temperature measurement from an upstream end of an air duct supplying air to a first heat exchanger and a second heat exchanger, wherein the first heat exchanger comprises a first heat exchanger inlet and a first heat exchanger outlet, wherein the first heat exchanger inlet is configured to receive pressurized air from a gas turbine engine operable to provide power to at least one vehicle of the fleet of vehicles;
• a second temperature measurement from a downstream end of the air duct;
• a third temperature measurement of air exiting the first heat exchanger;
• and
• a fourth temperature measurement of air exiting the second heat exchanger;
• and
• a first past heat exchanger fouling indication and a second past heat exchanger fouling indication associated with each past instance;
• a computer memory operable to store the received past instances of temperature measurements and associated first and second past heat exchanger fouling indications;
• a computer processor operable to generate a heat exchanger fouling model by calculating a regression model based on a supervised machine learning algorithm applied to the stored measurements and associated first and second past heat exchanger fouling indications;
• and
• a data output operable to transmit the generated heat exchanger fouling model to the fleet of vehicles;
• wherein a first present exchanger fouling indication and a second present heat exchanger fouling indication for a particular vehicle are calculated based on the generated heat exchanger fouling model and based further on a current instance of temperature measurements for the particular vehicle;
• wherein at least one of the first present heat exchanger fouling indication and the second present heat exchanger fouling indication exceeding a heat exchanger fouling threshold causes maintenance to be scheduled for at least one of a first heat exchanger and a second heat exchanger of the particular vehicle.