Abstract: A distributed bleed system temperature management scheme utilizes a distributed, closed loop temperature protection function. By allowing consumer systems to limit the consumer flow to meet a specified bleed system outlet temperature (which may be different for each consumer or group of consumers), each system can be penalized according to their level of importance. The closed loop approach allows optimization of the performance reduction instead of relying on conservative assumptions as is done with conventional systems. In some embodiments, each consumer system may have a different temperature limit at which the consumed flow is limited to maintain a given bleed system exit temperature. The temperature setpoints may be separated by a minimum temperature, based on sensor and controls tolerances, to ensure that the flow limiting functions do not interact with each other.

Abstract: A system and method are provided for controlling the temperature of engine bleed air from a turbofan gas turbine engine. The system includes a fan air valve and a fan air valve controller. The fan air valve is adapted to receive a flow of fan air from a turbofan gas turbine engine intake fan. The fan air valve is coupled to receive valve position commands and is configured, in response to the valve position commands, to move to a valve position to thereby control the engine bleed air temperature. The fan air valve controller is configured to implement a linear quadratic regulator (LQR) control. The fan air valve controller is adapted to receive a plurality of sensor signals, each sensor signal representative of one or more system parameters, and is configured, in response to the sensor signals, to supply the valve position commands to the fan air valve.

Abstract: A distributed bleed system temperature management scheme utilizes a distributed, closed loop temperature protection function. By allowing consumer systems to limit the consumer flow to meet a specified bleed system outlet temperature (which may be different for each consumer or group of consumers), each system can be penalized according to their level of importance. The closed loop approach allows optimization of the performance reduction instead of relying on conservative assumptions as is done with conventional systems. In some embodiments, each consumer system may have a different temperature limit at which the consumed flow is limited to maintain a given bleed system exit temperature. The temperature setpoints may be separated by a minimum temperature, based on sensor and controls tolerances, to ensure that the flow limiting functions do not interact with each other.

Abstract: A system and method are provided for controlling the temperature of engine bleed air from a turbofan gas turbine engine. The system includes a fan air valve and a fan air valve controller. The fan air valve is adapted to receive a flow of fan air from a turbofan gas turbine engine intake fan. The fan air valve is coupled to receive valve position commands and is configured, in response to the valve position commands, to move to a valve position to thereby control the engine bleed air temperature. The fan air valve controller is configured to implement a linear quadratic regulator (LQR) control. The fan air valve controller is adapted to receive a plurality of sensor signals, each sensor signal representative of one or more system parameters, and is configured, in response to the sensor signals, to supply the valve position commands to the fan air valve.