Vol 104, No 10 (2015)

To increase energy efficiency of vaporcompression air condition units it is advisable to use an additional regenerative indirect evaporative cooling with an indirect evaporative heat exchanger (IEHE). The paper gives the diagram of the combined air condition units, describes the principle of operation using IEHE as well as the IEHE constructions; the construction may be of two operating modes: crossflow and counterflow. The diagrams of the plant with the crossflow and counteflow IEHE are given in the paper. The tests of two types of IEHE were carried out to define which of them was more efficient. The operation of the heat exchangers were compared under conditions of dry, temperate and humid climate; the efficiency of the system was estimated by the “wet” thermometer and the duepoint temperature. The experiments showed the advantages of the counterflow system of flows in the IEHE that provided the efficiency higher by 30-50%. It was demonstrated that the preferable mode of water supply into the IEHE was that by the heat pump as the capillary forces could not wet to the right degree under hot climate conditions. The efficiency of the system may be enhanced using a humidifier of additional flow installed before the inlet into the IEHE. Keywords: air condition units, regenerative indirect evaporative cooling, indirect evaporative heat exchanger, crossflow and counterflow heat exchanger, efficiency of indirectvapor cooling.

The information of the perspective application of cryogenic engineering and high temperature superconductivity aboard an aircraft equipped mainly with electric wires is cited. Technical and economic prerequisites of using cryogenic engineering aboard are examined. The history of development of aircrafts at cryogenic fuel in the A.N. Tupolev design engineering bureau is covered. The perspectives of using onboard cryogenic generators, cryogenic electric drives of compressors of air conditioning and pressure maintenance systems, hydraulic pumps drives, linear electric drives of control and autonomous drives of the undercarriage, distributive and transformer nodes as well as onboard power electric wiring on the base of materials with properties of high temperature superconductivity are envisaged. The ways of their using in onboard electric systems to protect the schemes, circuits and machines from the impact of electromagnetic fields at high intensity Meisner effect consisting in pushout of the external magnetic field from the superconductors’ volume were charted. A low temperature, a light load and low energy losses in electric machines will allow realizing all types of transformations at more high efficiency excluding unproductive losses such as heating and voltage drop. Keywords: superconductivity, electric aircraft, onboard electric drive, cryogenic fuel.