Simulating faults in a Boeing 737-200 Environmental Control System using a thermodynamic model
The Environmental Control Systems ( ECS ), used to provide air to the aircraft cabin at the correct pressure and temperature, is a key driver of maintenance interruptions for military and civil aircraft. Fault detection is particularly difficult, due to the lack of instrumentation and the ability of the ECS’s control system to mask symptoms. Understanding how component degradation affects measurable thermodynamic parameters is key to developing a condition monitoring system for an ECS. This work focuses on the development of a thermodynamic model of a Boeing 737-200 ECS capable of simulating faults in three types of component: heat exchangers, valves, and water separators. The thermodynamic model has been validated using data collected on a ground-based instrumented B737-200 ECS. The results show how a thermodynamic model can be used to simulate the change of temperatures and pressures across the ECS when components degrade.
Degradation Model, physical modeling, aircraft systems, thermal systems
Chen, L., Zhang, Z., Wang, C. & Yang, C., 2015. Analysis on High-Pressure Water Separator. Procedia Engineering, pp. 558-566.
Chen, X., Yang, S., Sun, X. & Wang, L., 2015. Research on 1D-2D Co-simulation for Cabin Air Environment Accident. Procedia Engineering, Volume 121, pp. Pages 1983-1989.
Childs, T., Jones, A., Chen, R. & Murray, A., 2016. A Study into Refrigeration Cycle Working Fluids using an Air Cycle Machine Environmental Control System. s.l., 54th AIAA Aerospace Sciences Meeting.
Conceição, S. T., Zaparoli, E. & Turcio, H., 2007. Thermodynamic Study of Aircraft Air Conditioning Air Cycle Machine: 3-wheel × 4-wheel. s.l., SAE Brasil 2007 Congress and Exhibit.
Jordan, P. & Schmitz, G., 2014. A Modelica Library for Scalable Modelling of Aircraft Environmental Control Systems. s.l., Proceedings of the 10th International ModelicaConference.
Junior, J., Andrade, C. & Zaparoli, E., 2009. Numerical analysis of typical aircraft air conditioning air cycle machines. s.l., 20th Int. Congr. Mech. Eng..
Pérez Grande, I. & Leo, T., 2002. Optimization of a commercial aircraft environmental control system. Applied Thermal Engineering, Volume 22(17), pp. 1885-1904.
Scholz, D., Muller, C., Giese, T. & Erdmann, C., 2007. FLECS : Functional Library of the Environmental Control System - A simulation tool for the support of industrial processes.. s.l., 1st International Workshop on Aircraft System Technologies.
Scott, T. & Davis, G., 1976. Thermodynamics of Air / Water-Cycle Air- Conditioning Systems. s.l., International Compressor Engineering Conference .
Tetens, V., 1930. Uber einige meteorologische. Begriffe, Zeitschrift fur Geophysik, Volume 6, pp. 297-309.
Tu, Y. & Lin, G., 2011. Dynamic Simulation of Aircraft Environmental Control System Based on Flowmaster. Journal of Aircraft, 48(6).
Vargas, J. & Bejan, A., 2001. Integrative thermodynamic optimization of the environmental control system of an aircraft. International Journal of Heat and Mass Transfer, 44(20), pp. 3907-3917.