초록 ▼

An aircraft environmental control system (ECS) may be configured to operate in first mode and a second mode. The ECS may include an air cycle machine (ACM), a by-pass valve positioned to allow bleed air to by-pass the air cycle machine so that when the by-pass valve is open, the ECS operates in the

An aircraft environmental control system (ECS) may be configured to operate in first mode and a second mode. The ECS may include an air cycle machine (ACM), a by-pass valve positioned to allow bleed air to by-pass the air cycle machine so that when the by-pass valve is open, the ECS operates in the first mode with bleed air at a first pressure and when the by-pass valve is closed the ECS operates in the second mode at a second bleed air pressure, higher than the first bleed air pressure. A bleed air system controller and ECS controller may be configured to selectively couple high pressure or low pressure bleed air ports of an engine of an aircraft to the ECS and control the by-pass valve position.

대표청구항 ▼

1. An aircraft environmental control system (ECS) configured to operate in a first mode and a second mode, the ECS comprising: an air cycle machine (ACM):a by-pass valve positioned to allow bleed air to by-pass the air cycle machine; so that when the by-pass valve is open, the ECS operates in the fi

1. An aircraft environmental control system (ECS) configured to operate in a first mode and a second mode, the ECS comprising: an air cycle machine (ACM):a by-pass valve positioned to allow bleed air to by-pass the air cycle machine; so that when the by-pass valve is open, the ECS operates in the first mode with bleed air at a first pressure and when the by-pass valve is closed the ECS operates in the second mode at a second bleed air pressure, higher than the first bleed air pressure; anda bleed air system controller and ECS controller configured to selectively couple a high pressure bleed air port or a low pressure bleed air port of an engine of an aircraft to the ECS and control the by-pass valve position,wherein the bleed air is cooled by the ACM when the by-pass valve is closed,wherein the bleed air is not cooled by the ACM when the by-pass valve is open, andwherein the bleed air is cooled by a heat exchanger positioned in a ram air duct when the by-pass valve is open. 2. The system of claim 1 wherein the ECS controller is configured to: a) command opening of the by-pass valve when the aircraft is operating at altitudes above approximately 25,000 feet; andb) command closing of the by-pass valve when the aircraft is operating in ground taxi mode, climb, holding, or descent below an altitude of about 25,000 feet. 3. The system of claim 1 further comprising: a liquid cooling loop including; a liquid heat exchanger positioned in a ram air duct of the aircraft,a cabin air heat exchanger positioned in a pressurized area of the aircraft, andtubing interconnecting said heat exchangers, said tubing being configured to enable circulation of a liquid cooling medium through said heat exchangers,wherein a portion of air from a cabin is cooled in the cabin air heat exchanger by the liquid medium and recirculated to the cabin, andwherein the liquid medium is cooled in the liquid heat exchanger by ram air and recirculated to the cabin air heat exchanger. 4. An aircraft bleed-air power utilization system comprising: an environmental control system (ECS) configured to selectively operate in a first mode at a first bleed air pressure and in a second mode at a second bleed air pressure, the first bleed air pressure being lower than the second bleed air pressure; an air cycle machine (ACM) having a cooling turbine configured to cool bleed air when the ECS operates in the second mode; an aircraft engine having a first bleed air port positioned to extract bleed air from the engine at the first bleed air pressure and a second bleed air port positioned to extract bleed air from the engine at the second bleed air pressure; a by-pass valve positioned to eliminate pressure drop within the cooling turbine by directing bleed air from the first bleed air port, through a heat exchanger, around the cooling turbine and to stop the turbine when the ECS operates in the first mode, and a bleed air system controller and ECS controller configured to selectively couple the first bleed air port or the second bleed air port of the engine to the ECS and to control the by-pass valve, wherein the heat exchanger is positioned to transfer heat from bleed air to ram air. 5. The system of claim 4 further comprising: a water management assembly,wherein the by-pass valve is positioned to eliminate pressure drop within the water management assembly when the ECS operates in the first mode. 6. The system of claim 4 further comprising a bleed air system and an ECS controller configured to couple the first or second bleed air port to the ECS and control the by-pass valve position. 7. The system of claim 4 wherein the first bleed air port is positioned on the engine so that pressure of bleed air extracted from said first bleed air port matches bleed air requirements of the ECS when the by-pass valve is open. 8. The system of claim 4 wherein the second bleed air port is positioned on the engine so that pressure of bleed air extracted from said second bleed air port matches the bleed air requirements and operating modes of the ECS when the engine is operating at idle power. 9. The system of claim 4: wherein the engine is provided with a third bleed air port; andwherein the third bleed air port is positioned to extract bleed air at a pressure intermediate between the first and the second bleed air pressures. 10. The system of claim 9 wherein the third bleed air port is positioned so that when the ECS is coupled to the third bleed air port the ECS is operable at maximum flow at all aircraft altitudes in cruise with the by-pass valve in the closed position. 11. The system of claim 4: wherein the ECS is selectively coupled with a high pressure bleed air port and a low pressure bleed air port of the engine; andwherein a jet pump is selectively coupled with the high pressure bleed air port and the low pressure bleed air port of the engine. 12. A method for operating an aircraft bleed-air power utilization system comprising the steps of: operating a bleed air system controller and ECS controller to; selectively couple an environmental control system (ECS) to a first bleed air port or a second bleed air port of an engine of the aircraft, the first bleed air port providing bleed air at a first pressure and the second bleed air port providing bleed air at second pressure higher than the first pressure; direct bleed air from the second bleed air port to the ECS when the aircraft is in an idle mode of operation, direct bleed air from the first bleed air port to the ECS when the aircraft is in cruise, climb, hold or take off power, open a by-pass valve to direct bleed air to by-pass an air-cycle machine (ACM) of the ECS at altitudes higher than about 25,000 feet, and close the by-pass valve to direct bleed air through the air cycle machine turbine or turbines at altitudes lower than approximately 25,000 feet. 13. The method of claim 12 further comprising cooling bleed air through at least one heat exchanger positioned in a ram air duct of the aircraft. 14. The method of claim 12 further comprising cooling recirculated cabin air with an ambient air heat sink. 15. The method of claim 14 wherein the step of cooling recirculated cabin air includes transferring heat from the cabin into a liquid medium within a liquid cooling loop. 16. The method of claim 15: wherein heat from the cabin is transferred to the liquid medium within a heat exchanger positioned within a pressurized fuselage of the aircraft; andwherein cooling of the liquid medium is performed within a heat exchanger positioned in a ram air duct of the aircraft. 17. The method of claim 12 further comprising operating a jet pump between the first and second bleed ports to increase the first bleed port supply pressure. 18. The method of claim 12 further comprising coupling the ECS to a third bleed air port of the engine wherein the outlet pressure of bleed air at the third bleed air port is intermediate between outlet pressures of the first and second bleed air ports. 19. The method of claim 18 further comprising: operating the engine bleed air system with at least three ports; andselecting the engine bleed ports to be operated in accordance with: a). selecting the lowest pressure bleed port for normal operationb). selecting an intermediate pressure bleed port when the aircraft experiences an ECS single pack failure, flight at 40,000 feet or higher or a cooling demand that cannot be satisfied with only ambient air cooling, or when other user systems pressure requirements exceed that of the lower bleed port, andc). selecting the highest bleed port for descent and conditions when the engine is operating at idle power.