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EP-4011778-B1 - RECIRCULATION GROUND MAINTENANCE MODE

EP4011778B1EP 4011778 B1EP4011778 B1EP 4011778B1EP-4011778-B1

Inventors

  • Shea, Brian R.
  • ZYWIAK, PETER
  • MARTIN, LUKE

Dates

Publication Date
20260506
Application Date
20211206

Claims (10)

  1. An aircraft air conditioning system comprising: a lower cooling zone including a lower recirculation heat exchanger (118) of the aircraft air conditioning system, the lower recirculation heat exchanger configured to receive cabin air from a cabin of the aircraft and to convert the cabin air into lower cooled recirculated cabin air; an upper cooling zone including an upper recirculation heat exchanger (133) of the aircraft air conditioning system, the upper recirculation heat exchanger configured to receive the cabin air from the aircraft cabin and to convert the cabin air into upper cooled recirculated cabin air; a power system (108) configured to selectively deliver power to the lower cooling zone and the upper cooling zone; a manifold (120); a ram air circuit (110) in fluid communication with the manifold; a pressurization air cycle kit, PACK, (109) in signal communication with the power system to selectively receive the power; a lower recirculation fan (116) configured to deliver a first portion of the cabin air to the lower recirculation heat exchanger (118) in response to receiving the power from the power system, and wherein the lower recirculation heat exchanger is configured to convert the first portion of the cabin air into the lower cooled recirculated cabin air; an upper recirculation fan (130) configured to deliver a second portion of the cabin air to the upper recirculation heat exchanger (133) in response to receiving the power from the power system, and convert the second portion of the cabin air into the upper cooled recirculated cabin air; and a controller (150) in signal communication with the power system, the controller configured to determine a target temperature of the aircraft cabin and invoke a recirculation ground maintenance mode that commands the power system to deliver power to one or both of the lower cooling zone and the upper cooling zone so that a temperature of the aircraft cabin reaches the target temperature, wherein the controller invokes the recirculation ground maintenance mode invoking a combination of the upper and lower cooling zones such that lower cooled recirculation cabin air is delivered to the manifold (120) which outputs the cooled cabin supply air directly to the aircraft cabin, and the upper cooled recirculated cabin air is delivered directly to the aircraft cabin while the cooled cabin supply air output from the manifold (120) is output directly to the aircraft cabin, wherein in response to invoking the recirculation ground maintenance mode, the controller is configured to command the power system to disconnect the power to the PACK, and the manifold outputs cooled cabin supply air that is delivered to the aircraft cabin to reduce the cabin temperature.
  2. The aircraft air conditioning system of claim 1, further comprising a supplemental cooling system, SCS, (106) configured to deliver a heat transfer fluid to the lower recirculation heat exchanger and the upper recirculation heat exchanger.
  3. The aircraft air conditioning system of claim 2, wherein in response to invoking the lower cooling zone, the controller (150) commands the power system to deliver power to the lower recirculation fan while commanding the power system to disconnect from power to the upper recirculation fan, and optionally, wherein in response to invoking the lower cooling zone, the lower cooled recirculated cabin air is delivered to the manifold (120) to output the cooled cabin supply air.
  4. The aircraft air conditioning system of claim 2, wherein in response to invoking the upper cooling zone, the controller (150) is configured to command the power system to deliver power to the upper recirculation fan (130) while commanding the power system to disconnect from power to the lower recirculation fan (116), and optionally wherein in response to invoking the upper cooling zone, the upper cooled recirculated cabin air is delivered to the aircraft cabin while the lower cooled recirculated cabin air is blocked from reaching the manifold (120).
  5. The aircraft air conditioning system of claim 4, wherein in response to invoking the upper cooling zone, the recirculated cabin air (115) is delivered to the manifold to output the cooled cabin supply air (121).
  6. The aircraft air conditioning system of claim 2, wherein in response to invoking the combination of the lower and upper cooling zones, the controller (150) is configured to command the power system to deliver power to the lower and upper recirculation fans, and optionally wherein in response to invoking the combination of the lower and upper cooling zones, the lower cooled recirculated cabin air is delivered to the manifold (120) to output the cooled cabin supply air and the upper cooled recirculated cabin air is delivered to the aircraft cabin.
  7. A method of controlling an aircraft air conditioning system of an aircraft cabin, the method comprising: delivering cabin air to a lower recirculation heat exchanger (118) included in a lower cooling zone; delivering the cabin air to an upper recirculation heat exchanger (133) included in an upper cooling zone, the upper recirculation heat exchanger configured to receive the aircraft cabin air from the cabin and to convert the cabin air into upper cooled recirculated cabin air; generating power via a power system (108); and determining, via a controller (150), a target temperature of the aircraft cabin; and invoking, via the controller, a recirculation ground maintenance mode to command the power system to deliver power to one or both of the lower cooling zone and the upper cooling zone so that a temperature of the aircraft cabin reaches the target temperature, commanding, via the controller, the power system to disconnect the power to a pressurization air cycle kit, PACK, (109) in response to invoking the recirculation ground maintenance mode; and selectively delivering a first portion of the cabin air to the lower cooling zone and selectively delivering a second portion of the cabin air to the upper cooling zone independently from the first portion of the cabin air, wherein the controller invokes the recirculation ground maintenance mode invoking a combination of the upper and lower cooling zones such that lower cooled recirculation cabin air is delivered to a manifold (120) which outputs the mixed cooled cabin supply air directly to the aircraft cabin, and the upper cooled recirculated cabin air is delivered directly to the aircraft cabin; and wherein the method further comprises: delivering power from the power system to a lower recirculation fan (116) included in the lower cooling zone; and delivering the first portion cabin air to the lower recirculation heat exchanger in response to powering the lower recirculation fan, and further comprising: delivering power from the power system to an upper recirculation fan (130) included in the upper recirculation zone; and delivering the second portion of the cabin air to the upper recirculation heat exchanger in response to powering the upper recirculation fan.
  8. The method of claim 7, wherein in response to invoking the lower cooling zone, the controller commands the power system to deliver power to the lower recirculation fan while commanding the power system to disconnect from power to the upper recirculation fan, and optionally wherein in response to invoking the upper cooling zone, the controller commands the power system to deliver power to the upper recirculation fan while commanding the power system to disconnect from power to the lower recirculation fan.
  9. The method of claim 8, wherein in response to invoking a combination of the lower and upper cooling zones, the controller commands the power system to deliver power to the lower and upper recirculation fans.
  10. The method of claim 9, wherein in response to invoking a combination of the lower and upper cooling zones, simultaneously delivering the first portion of the cabin air to the lower cooling zone and the second portion of the cabin air to the upper cooling zone.

Description

BACKGROUND Embodiments of the disclosure relate to environmental control systems, and more specifically to an environmental control system of an aircraft. The trend in the aerospace industry today is towards systems with higher efficiency. Modern wide body commercial aircraft are trending toward inclusion of a Supplemental Cooling System (SCS herein) that supplements aircraft cooling operations provided by the aircraft's main aircraft Environmental Control System (ECS). The SCS includes a conditioned fluid loop that ties into the recirculation air system via a heat exchanger to cool recirculation air. The SCS fluid may be conditioned via a range of cooling sources, including but not limited to a vapor cycle refrigeration system. The cooled recirculated air is used to cool the aircraft cabin, while the vapor cycle refrigeration system dumps the heat load to either a coupled fluid loop or directly to an aircraft ram air circuit included in the ECS. Currently, the SCS operates while the entire ECS (including the ECS pressurization air Conditioning kits referred to as "PACKS") is also operating in order to provide cabin temperatures within the required range with typical passengers on board and typical aircraft level heat loads operational. ECS are disclosed in EP 3 333 078, US 2013/327891, EP 3 489 143 and US 2017/144767. EP3 333 078 discloses an air conditioning system comprising cooling zones, the coolings zones comprising thermal electronic cooler modules. The air conditioning system further comprising cabin recirculation fans and a mix manifold. BRIEF DESCRIPTION According to one aspect, an aircraft air conditioning system is provided as defined by claim 1. According to another aspect, a method of operating an aircraft air conditioning system is provided as defined by claim 7. BRIEF DESCRIPTION OF THE DRAWINGS The following description should not be considered limiting in any way. With reference to the accompanying drawing, like elements are numbered alike: FIG. 1 illustrates an aircraft air conditioning system according to a non-limiting embodiment;FIG. 2 illustrates the aircraft air conditioning system of FIG. 1 operating in a recirculation ground maintenance mode that invokes a lower cooling zone according to a non-limiting embodiment;FIG. 3 illustrates the aircraft air conditioning system of FIG. 1 operating in a recirculation ground maintenance mode that invokes an upper cooling zone according to a non-limiting embodiment;FIG. 4 illustrates the aircraft air conditioning system of FIG. 1 operating in a recirculation ground maintenance mode that invokes a combination of upper and lower cooling zones according to a non-limiting embodiment; andFIG. 5 is a flow diagram illustrating a method of operating an aircraft air conditioning system in a recirculation ground maintenance mode according to a non-limiting embodiment. DETAILED DESCRIPTION A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. Airline maintenance operations sometimes require minimal staff onboard for cleaning procedures and maintenance tasks. In order to keep a habitable environment, many times the full ECS (including the ECS PACKS) is run along with the SCS to provide conditioned air supply into the cabin and flight deck. The ECS air conditioning PACKS represent a significant load on the ECS and require a substantial amount of power to operate. Therefore, operating the ECS conditioning PACKS consumes a large amount of fuel. However, in instances where maintenance operations are performed, overall occupancy of the aircraft is very low (only a few people on board) and thus operation of the full ECS is unnecessary. One or more non-limiting embodiments described herein relate to aircraft air conditioning system configured to selectively initiate a recirculation ground maintenance mode configured to provide cool air while reducing the power to the ECS. The recirculation ground maintenance mode controls flow of recirculated cabin air and cooled recirculated cabin air through a recirculation circuit without operating the ECS at full capacity. For example, the ram air system of the ECS can be operated without operating the ECS PACKS. The ram circuit can contain additional heat exchangers tied directly or via coupled fluid loops to the Supplemental Cooling System (SCS). In this manner, the aircraft cabin can be cooled without operating the ECS at full capacity, thereby significantly reducing fuel costs and improving power efficiency. In one or more non-limiting embodiments, the recirculation ground maintenance mode is configured to invoke a plurality of different cooling zones of the aircraft air conditioning system. The different cooling zones include, for example, a lower cooling zone, an upper cooling zone, and a combined upper and lower cooling zone. Selecting or deselecting the different cooling zones controls the