GB831876A - Improvements in and relating to cooling of individual compartments of aircraft - Google Patents

Abstract

831,876. Air cooling installations; refrigerating. NORMALAIR Ltd. Jan. 30, 1958 [Feb. 13, 1957], No. 4841/57. Classes 29 and 64(3) In a system for the cooling of individual compartments 43, 44 in aircraft, air is blown by a fan or like air-moving means over an air-cooling heat exchanger through which flows a liquid medium which has been in heat transfer relationship with a part (e.g. the evaporator) of a refrigerating system, the fan or like air-moving means being caused to operate under the influence of said liquid medium, e.g. through a turbine. In the form shown similar cooling systems 1, and 2, are respectively associated with each of two compartments 43, 44 to be cooled to differing temperatures. In for example the system 1, an air turbine 4 drives a pump 3 which circulates the liquid medium through a circuit comprising turbine 9, heat exchanger 7 (or by-pass 13 controlled by a temperature responsive valve 14), and cooler 16. The turbine 9 drives a fan 8 which blows air from compartment 43 over the air cooling heat exchange 7. The now warmed liquid is re-cooled in flowing through cooler 16 which comprises an evaporator of a two stage compressorevaporator type refrigerating system 28. In the system 28 refrigerant is compressed in a low pressure compressor 29 (driven by an air turbine 30) and then in a high pressure compressor 32 (driven by an air turbine 33). The refrigerant flows then through parallel-connected condensers 35, 36 in which heat is rejected to fuel and water, and then through an evaporator 27 which comprises the circulating fluid cooler in the compartment 44. The condenser 36 is only operative during overload or emergency conditions. Evaporator 27 communicates with the inlet side of high pressure compressor 32 by way of conduit 39 and with evaporator 16 by way of conduit 40 which incorporates an expansion valve 41. The refrigerant leaving evaporator 27 through conduit 40 is at a lower temperature than that leaving through conduit 39. Hence compartment 43 may be maintained at a lower temperature than compartment 44. The circulating liquid in the systems 1, 2 preferably comprises a water/antifreeze mixture the proportions of which may differ for each compartment.