Enhancement of the Operation Efficiency of the Transport Air Conditioning System

On analyzing the operation of air coolers of railway air conditioning (AC) systems, characterized by considerable variations in current heat loads according to actual climatic conditions on the route lines, the reserves to increase its efficiency by the intensification of refrigerant evaporation in air coils and to enlarge the range of deviation of refrigerant flows from their optimum values without noticeable decreasing heat flux were revealed. It has been proved that overfilling the air cooler coils by liquid refrigerant injector recirculation enables excluding the final dry-out stage of refrigerant evaporation with extremely low intensity of heat transfer and as result provides increasing the heat efficiency of air coolers (overall heat flux) by 20–30% compared with conventional air coolers with complete refrigerant evaporation and superheated vapor at the exit. Moreover, a larger deviation of current heat load on railway route lines is permitted without considerable falling air cooler heat efficiency due to refrigerant injector recirculation at available many circulations. The method to determine the rational design heat load on air coolers of railway AC systems, providing closed to maximum refrigeration output generation over the considered period, was developed.