DOI: 10.1615/ICHMT.2008.CHT
ISBN Print: 978-1-56700-253-9
ISSN: 2578-5486
ANALYSIS OF A PRESSURE CONTROLLER FOR COMPRESSED NATURAL GAS (CNG) INJECTION SYSTEMS IN COMBUSTION ENGINES
摘要
The number of motor vehicles powered by internal combustion engines continues to grow despite shrinking oil reserves. As a result, compressed natural gas (CNG) is gaining importance as an emerging combustion engine fuel. Although the preparation of the fuel/air mixture for a combustion system is essential to the combustion and hence the heat addition to this day CNG systems − e.g., in passenger cars − are not fully integrated into the development process as conducted by vehicle or engine manufacturers. Instead, they are usually adapted in at a downstream stage by small specialized companies so that there is still a big potential for further development on any part of the system.
This paper is focused on improvements of pressure controllers for CNG combustion systems. Initially it outlines the state of the art in advanced gas injection technologies. In particular, the development towards sequential injection within the fuel preparation systems is described. A pressure regulator for CNG driven combustion engines is examined in detail, given its role as a highly sensitive and critical system component. Based on a precise theoretical analysis, a linear model of this pressure regulator is derived and subjected to dynamic simulation.
The analytical approach is accompanied by an experimental investigation of the device. On a test rig developed at the Trier University of Applied Sciences, the static and dynamic features of the pressure regulator can be measured with the requisite precision. The comparison of measured and simulated data yields a validation of the dynamic simulation model. With the approaches developed it is now possible for the first time to model, simulate and optimize single- or multi-stage pressure regulators for CNG driven engines with less effort and higher accuracy.