Pack management system for environmental control system

An air conditioning pack management system for controlling distribution of a predetermined amount of conditioned air from a system comprising two or more air conditioning packs, the pack management system comprising a management unit arranged to apportion the predetermined amount of conditioned air to be provided by one or more of the two or more air conditioning packs based on pre-selected metrics,

• wherein the pre-selected metrics include the respective operating efficiencies of each of the two or more air conditioning packs, and
• wherein, depending on the predetermined amount of conditioned air, and based on the pre-selected metrics including the respective operating efficiencies of each of the two or more air conditioning packs relative to their maximum operating efficiencies, the pack management system is configured to apportion the predetermined amount of conditioned air unequally between the two or more air conditioning packs such that one of the two or more air conditioning packs provides a greater proportion of the predetermined amount of conditioned air that the other/another of the two or more air conditioning packs so to maximize the efficiency of each of the two or more air conditioning packs;
• pack management system apportions by solving an optimization problem:
• [
• m
• .
• 1
• m
• .
• 2
• ⋮
• m
• .
• Npacks
• ]
• =
• max
• ⁢
• ∑
• i
• =
• 1
• N
• packs
• η
• i
• s
• .
• t
• .
• 1.
• 
• ∑
• i
• =
• 1
• N
• packs
• ⁢
• m
• .
• i
• =
• m
• .
• TOT
• 2. system stability
• Where:
• ηi is the efficiency of the i-th pack;
• {dot over (m)}i is an optimization variable that corresponds to the inlet external airflow to the i-th pack;
• and
• {dot over (m)}TOT is the total external mass air flow.