Transient Thermal Management of Vapor Cycles to Simulate Aircraft Electrical Environment Control Systems

Abstract

A Modelica library has been developed to simulate both transient and steady state of vapor cycle systems (VCS) integrated within Electrical Environment Control Systems (E-ECS) architectures applied in the thermal management of aircrafts. The numerical resolution of each one of different components: heat exchangers with special attention on two-phase due to their non-linearity; compressors based on parametric curves, valves, accumulators, and auxiliary elements, are detailed, looking for multi-level approach and object-oriented nature. Strategies for transient loop resolution system are also analyzed. A compromise between fast and robust resolution with a enough accuracy has been assured. Numerical results obtained are devoted not only to highlight the system and components robustness with low computational time, but also allow having a better understanding of system behavior on heat exchanger performance, refrigerant mass flow management, initialization cases, system control and transient conditions, becoming a virtual tool for real working conditions.