Entropy-statistical analysis of the air conditioning cycle of an aircraft

Abstract

Most modern aircrafts widely use air conditioning systems in order to ensure comfortable flight conditions for passengers and crew, as well as to cool the equipment of the aircraft. The aircraft in-dustry is developing every year and the requirements for such systems are growing. Preliminary calculations and analysis of such systems are of key importance in their development. Such calcula-tions will help to determine the entire further path of system development and prevent many errors. They also help to regularly improve the performance of systems, in particular, their energy charac-teristics. The main requirements for systems are reliability, energy efficiency, and weight-and-dimensional characteristicss. The paper is devoted to analysis of the efficiency of the system and its individual units. In addition, there is considered separately the influence of third-party factors on the efficiency of the system, in particular, the presence of moisture in the working air flow. This article discusses the results of thermodynamic calculation and analysis by the entropy-statistical method of the air conditioning system in various operating modes. The efficiency of the system as a whole is considered and the influence of imperfection of each of its units in particular is analyzed. The standard parameters of the operation of such systems on airplanes were taken as the initial parameters for calculating the systems. For the analysis, a system with a two-wheel turbo-cooling unit with moisture removal on the high-pressure path was selected. A schematic diagram of the system is given, formulas for calculating the minimum required work to compensate the production of entropy for the units of the system are presented. To ensure the calculations, the software complexes MathCAD, Coolprop and Matlab were used.