Sensor positioning and thermal model for condition monitoring of pressure gas reservoirs in vehicles



Published Jul 1, 2018
Henrik Bücking Raphael Pfaff Roger Dirksmeier


Passively acting safety relevant systems, e.g. automatic fire extinguishing systems or brakes, rely on the availability of compressed gases as acting medium and energy storage. Due to the safety relevance of these systems, it is necessary to monitor the condition of these elements continuously. However this task is difficult due to the partly abrupt changes in environmental temperature due to tunnel crossings and the interrelation of temperature and pressure in gases. As further the direct measurement of the gas temperature is difficult and costly, it is desirable to use external sensors to estimate the average gas temperature while at the same time avoiding false positives as not to reduce availability of the subsystems.

For this reason, the present paper analyses the behavior of a cylindrical pressure reservoir during changes in the environment temperature. The gas under consideration is Nitrogen under a pressure of approximately $200\,\mathrm{bar}$ at $15\,^{\circ}\mathrm{C}$.
Aiming to identify a dynamical model of the gas temperature, different temperature profiles were simulated while measuring gas-pressure and temperatures in two locations within the gas reservoir as well as on the cylinder wall.

From the recorded data, a dynamical model is identified which expresses the relation between environmental and mean gas temperature. The estimated gas temperature from this system model is used to determine a reference pressure which can be compared to the observed pressure. In case of any mass flow from the reservoir, the error grows and an error can be triggered.

The model was developed using temperature curves resembling true operational curves simulated in a climatic chamber. The detection and classification behaviour was tested using computer simulations.

How to Cite

Bücking, H., Pfaff, R., & Dirksmeier, R. (2018). Sensor positioning and thermal model for condition monitoring of pressure gas reservoirs in vehicles. PHM Society European Conference, 4(1).
Abstract 331 | PDF Downloads 336



Pressure vessel, Condition monitoring, Temperature shock

Technical Papers