Abstract: A method and system for predicting heat exchanger blockage in an aircraft is provided. The method includes generating a reduced order model (ROM) that predicts a ram air fan (RAF) surge margin that correlates to a heat exchanger blockage parameter, calculating, using the ROM, a predicted RAF surge margin value using a sensor signal received from a sensor connected to a ram air fan (RAF), calculating the heat exchanger blockage parameter using at least the predicted RAF surge margin value, and reporting, to a user, the heat exchanger blockage parameter that indicates when a heat exchanger blockage condition is present.

Abstract: A method of controlling an outlet temperature of a heat exchanger of an aircraft includes operating an air cycle machine at a first operating speed. The air cycle machine is operatively coupled to an air cycle machine bypass valve at a first position. The air cycle machine is fluidly connected to a first heat exchanger disposed adjacent to a second heat exchanger. In response to a second heat exchanger outlet temperature less than a second heat exchanger outlet temperature threshold while the aircraft is operating at an altitude less than an altitude threshold, the method moves the air cycle bypass valve from the first position toward a second position.

Abstract: An airplane is provided. The airplane includes a vapor cycle air conditioning system that receives outside air, a bleed system with at least one port, and an electric fan. A source of outside air when the airplane is on ground is forced air from the electric fan. The source of the outside air when the airplane is at cruise is bleed air from the at least one port.

Abstract: A system is provided. The system includes a first environmental control sub-system, operating in a first mode, that receives a first medium at a first flow amount and a first pressure. The system also includes a second environmental control sub-system, operating in a second mode, that receives a second medium at a second flow amount and a second pressure. The first flow amount is greater than the second flow amount, and the second pressure is greater than the first pressure.

Abstract: A system includes an inlet line configured to receive a medium flowing from a low-pressure location of an engine to a chamber, a plurality of heat exchangers configured to receive the medium from the inlet line, and a valve located upstream from the plurality of heat exchangers. The valve is configured to divide in parallel the medium across at least a first heat exchanger and a second heat exchanger of the plurality of heat exchangers.

Abstract: An airplane is provided. The airplane includes a pressurized compartment and an environmental control system. The environmental control system includes a compressing device. The compressing device includes a compressor and a turbine. The airplane also includes a first flow of first medium configured to enter the pressurized compartment and a second flow of the first medium configured to enter the turbine.

Abstract: A system and method that comprises an air cycle machine, a flow of bleed air, at least one heat exchanger, and an inlet configured to supply the flow of the bleed air is provided. The bleed air directly flows from a source to mix with recirculated air downstream of a compressor of the air cycle machine in accordance with a high pressure mode or a recirculation chilling mode. The system and method can also utilize the recirculated air flowing from the chamber to drive or maintain the air cycle machine in accordance with the above modes.

Abstract: A system and method that comprises an air cycle machine, a flow of bleed air, at least one heat exchanger, and an inlet configured to supply the flow of the bleed air is provided. The bleed air directly flows from a source to either a compressor of the air cycle machine or the at least one heat exchanger in accordance with a high pressure, low pressure, or pressure boost operation mode. The system and method also can also utilize recirculated air flowing from the chamber to drive or maintain the air cycle machine in accordance with the above modes.

Abstract: A system and method that comprises an air cycle machine, a flow of bleed air, at least one heat exchanger, and an inlet configured to supply the flow of the bleed air is provided. The bleed air flows from a source to mix with recirculated air in accordance with a high pressure mode or a recirculation chilling mode. The system and method also can also utilize the recirculated air flowing from the chamber to drive or maintain the air cycle machine in accordance with the above modes.

Abstract: A nose cone assembly for a gas turbine engine and method of circulating air in a gas turbine engine are disclosed. The nose cone assembly includes a nose cone having an aperture communicating air to an interior space of the nose cone and a discharge member communicating the air out of the nose cone.

Abstract: A replacement system, which includes a plurality of heat exchangers and a compressing device, is configured to prepare in parallel a medium bled from a low-pressure location of an engine and flowing through a plurality of heat exchangers into a chamber. The compressing device is in communication with the plurality of heat exchangers and regulates a pressure of the medium flowing through the plurality of heat exchangers. The replacement system employs a subsystem to treat the medium from the low-pressure location of the engine before it is received by the inerting system.

Abstract: A system, which includes a plurality of heat exchangers and a compressing device, is configured to prepare in parallel a medium bled from a low-pressure location of an engine and flowing through a plurality of heat exchangers into a chamber. The compressing device is in communication with the plurality of heat exchangers and regulates a pressure of the medium flowing through the plurality of heat exchangers.

Abstract: A system, which includes a plurality of heat exchangers and a compressing device, is configured to prepare in parallel a medium bled from a low-pressure location of an engine and flowing through a plurality of heat exchangers into a chamber. The compressing device is in communication with the plurality of heat exchangers and regulates a pressure of the medium flowing through the plurality of heat exchangers. The compressing device is bypassed based on the preparing in parallel the medium for the chamber, which in turn enables the compressing device to windmill. Therefore, the system employs at least one mechanism to prevent components of the compressing device from windmilling.

Abstract: An air separation system includes a high temperature ozone converter, a mechanical separator downstream of the high temperature ozone converter, and an air separator downstream of the mechanical separator. The air separator receives high temperature air and provides high temperature nitrogen-enriched air and high temperature oxygen-enriched air. The air separation system further includes a heat exchanger downstream of air separator that receives and cools the high temperature nitrogen-enriched air.

Abstract: A bleed air supply system configured to supply bleed air from an engine to an environmental control system (ECS) pack is provided including a high pressure port configured to bleed air from a high spool of the engine. An intermediate pressure port is configured to bleed air from the high spool of the engine. The bleed air at the intermediate pressure port has a pressure less than the bleed air at the high pressure port. A precooler is fluidly coupled to the ECS pack, the high pressure port and the intermediate pressure port. Bleed air from the high pressure port and the intermediate pressure port is conditioned in the precooler before being provided to the ECS pack. A low pressure port is configured to bleed air from a low spool of the engine. The bleed air from the low pressure port bypasses the precooler and is supplied directly to the ECS pack.

Abstract: A method and apparatus for operating an air cycle machine is disclosed. The apparatus includes a detector for measuring a rotational speed of a component of the air cycle machine. A processor estimates a rate of change of rotational speed of the component from the measured rotational speed and shuts down the air cycle machine when the estimated rate of change of the rotational speed of the component is greater than a selected rate threshold.

Abstract: An aircraft environmental conditioning system is disclosed that includes an air cycle system for conditioning a flow of hot compressed air by reducing its temperature and pressure. The air cycle system includes a heat exchanger having a heat rejection side in fluid communication with the airflow and a heat absorption side in fluid communication with external unconditioned air. The system also includes an airflow path from an external air inlet to the heat absorption side of the heat exchanger. A centrifugal separator is disposed in the airflow path, and includes a tubular body portion having an inlet that receives airflow, a deflector in the tubular body portion that imparts a vortex motion to airflow in the tubular body portion, and an outlet portion that includes a clean air outlet in fluid communication with the heat absorption side of the heat exchanger and a scavenge air outlet for removing particulate matter.

Abstract: A system, which includes a plurality of heat exchangers and a compressing device, prepares a medium bled from a low-pressure location of an engine and flowing through a plurality of heat exchangers into a chamber. The compressing device is in communication with the plurality of heat exchangers and regulates a pressure of the medium flowing through the plurality of heat exchangers. The compressing device includes a turbine that provides supplemental power to the compressing device based on a pressure of the medium in the chamber.

Abstract: Embodiments relate to heat exchanger contamination monitoring in an air conditioning system. An aspect includes receiving, by a contamination monitoring logic from a primary heat exchanger outlet temperature sensor, a first temperature comprising an air temperature at an outlet of a primary heat exchanger. Another aspect includes receiving, from a secondary heat exchanger outlet temperature sensor, a second temperature comprising an air temperature at an outlet of a secondary heat exchanger. Another aspect includes receiving, from a compressor outlet temperature sensor, a third temperature comprising an air temperature at an outlet of a compressor. Another aspect includes determining, based on the first, second, and third temperature, a heat exchanger contamination value. Another aspect includes comparing the heat exchanger contamination value to a predetermined contamination threshold.

Abstract: An engine bleed air system having one or more taps in the compressor section of an aircraft engine, for example a low pressure tap and a high pressure tap. The low pressure tap is fluidly connected to the compressor of a turbo-compressor and the high pressure tap is fluidly connected to the turbine of the turbo-compressor. A bypass line connects the high pressure air to the outlet of the compressor, with a heat exchanger used to remove excess heat from the bypass line. An additional heat exchanger is used to remove any excess heat from the compressed air, dumping the heat to a fan stream or to the expanded air exiting the turbine. The system is controlled to minimize the amount of high pressure air extracted from the engine.