한국액체미립화학회지 제20 권 제3 호(2015) http://dx.doi.org/10.15435/JILASSKR.2015.20.3.195 A Comprehensive Study on Fuel Injector Test Bench for Heavy Duty Engine Shubhra Kanti Das * , Sakda Thongchai * , and Ocktaeck Lim *,† Key Words: Heavy duty injector, Injector test bench, Injection quantity, Injection pressure Abstract This study discusses a fuel injector test bench containing a mechanical type fuel supply system for heavy duty diesel engine. The main focus of this study was to evaluate the design stability of the test bench, which basically measures the injector durability of a multi-hole heavy duty injector by using pure diesel as a test fuel. In this experiment, diesel spray was controlled by a specially designed control box and all the experiments were carried out to measure e.g. fuel injection pressure and fuel injection quantity to understand the injection status which is interlinked with the stability factor of total test bench design. Also, the durability test was performed to understand the heavy duty operation lastingness of the designed system and the flow rate of the installed distributor pump in the fuel supply system of this studying test bench was compared with LO-1 and LO-2 pump. The results of the above mention tests revealed that the injector test bench design and control system can serve the purpose for heavy duty injector. 1. Introduction Diesel engine plays a dominant role in the field of power, propulsion and energy. Today’s diesel engine performance, power output economy is greatly dependent on the effectiveness of the fuel injection system. The fuel on injection system has to perform the important duty of initiating and controlling the combustion process (1) . In the off-highway diesel engine market, the traditional injection system is also gradually replaced by the high-pressure fuel injection systems (2) . In the present day’s injection system of diesel engines are designed to obtain higher injection pressure (3, 4) . Also, the key goal to reduce the exhaust emission by increasing efficiency with the help of the advanced injection system (5) . When the injection pressure will increase, the fuel particle becomes small. If the injection pressure is too high, the ignition delay period becomes shorter and hence the possibilities of homogeneous mixture reduced and eventually the combustion efficiency dropped (6,7) . For lifetime verifi- cation of an automotive components it is important to simulate injection phenomena in a test bench that certainly regenerate some more boundary conditions to understand the fuel system design which will help researchers to elevate a more stable future test bench system. Again diesel fuel spray penetration depends to a great extent on injection pressure, fuel properties, and nozzle geometry. In a mechanically controlled fuel injection system, the injection pressure increases together with increasing engine speed and load (8) . For measuring the durability of a heavy duty injec- tor for heavy duty engine, a test bed was designed along with a mechanical type distributor inline fuel supply system which can be controlled by pressing the buttons of a control box. This paper aims to com- (Recieved: 12 Sep 2015, Recieved in revised form: 29 Sep 2015, Accepted: 30 Sep 2015) * 울산대학교 대학원 기계공학과 † 책임저자, 회원, 울산대학교 기계공학부 E-mail: otlim@ulsan.ac.kr TEL: (052)259-2852 FAX: (052)259-1680