초록 ▼

An aircraft cabin air-conditioning system, of the type that uses engine bleed air, regulates the amount of tapped bleed air so as to be just sufficient to maintain a desired cabin pressure, thus minimizing the fuel burn allocated to the aircraft\s environmental control system. The air-conditioning s

An aircraft cabin air-conditioning system, of the type that uses engine bleed air, regulates the amount of tapped bleed air so as to be just sufficient to maintain a desired cabin pressure, thus minimizing the fuel burn allocated to the aircraft\s environmental control system. The air-conditioning system cools the bleed air by passing it first through a heat exchanger 50 of a circulating glycol/water coolant loop 55 for heat transfer to a coolant and then through an evaporator 60 of an electrically-driven vapor-cycle loop 56 for supplemental heat transfer to a refrigerant. The rate at which the refrigerant is circulated through the evaporator 60 is regulated to be just sufficient to provide a required supplemental cooling capacity, thereby minimizing electrical power consumed by a compressor 63 that forms part of the vapor-cycle loop 56. A subbranch of the coolant loop 55 carries the coolant through a condenser 64 of the vapor-cycle loop 56 where there is an additional transfer of heat to the coolant. Bulk fuel in the aircraft fuel tanks as well as heat loss from the wing\s lower and upper skin surfaces during flight are used as a heat sink for heat that has been transferred from the bleed air to the coolant, and for this purpose the coolant loop 55 circulates the fluid coolant through a fuel-cooled heat exchanger 59. To further conserve the volume of air that must be bled from the engine, used cabin air is filtered and recirculated through the evaporator 60 of the vapor-cycle loop 56 where it is recooled prior to being reintroduced into the cabin.

대표청구항 ▼

A fuel conserving air-conditioning apparatus for an aircraft cabin that operates effectively with a supply of air bled from a turbo-fan engine at minimal pressure and temperature, comprising: flow control means for receiving engine bleed air and for passing a constant volumetric rate of flow of such

A fuel conserving air-conditioning apparatus for an aircraft cabin that operates effectively with a supply of air bled from a turbo-fan engine at minimal pressure and temperature, comprising: flow control means for receiving engine bleed air and for passing a constant volumetric rate of flow of such bleed air; a coolant loop including an air-to-coolant heat exchanger means for receiving bleed air passed by said flow control means and for transferring heat therefrom to a coolant so as to cause a partial cooling of the bleed air, heat sink means for receiving said coolant and extracting heat therefrom, and means for circulating said coolant through said heat exchanger means and said heat sink means; a vapor-cycle loop including an evaporator means for receiving the partially cooled bleed air from said heat exchanger and for receiving and evaporating a liquid-state refrigerant to a vapor state in heat exchange relation with said bleed air so as to extract additional heat therefrom and cause further cooling of the bleed air, compressor means for compressing the vapor-state refrigerant, and condenser means for condensing the thusly compressed vapor-state refrigerant to a liquid state, and means for circulating said refrigerant through said evaporator means, compressor means and condenser means; duct means for ducting bleed air from said evaporator means to an aircraft\scabin; and means for controlling the rate of circulation of said refrigerant in said vapor-cycle loop as a function of air temperature in an aircraft\s cabin so as to regulate the degree of said further cooling of the bleed air.