/ 147 Average Injection Rate for 5x Multiple Injection Time ms Injection Rate Injector Piston Displacement mm 24 16 8 0 1 0 8 0 -8 -6 -4 -2 0 2 4 6 8 10 12 14 16 18 20 22 0,2 0,1 0,0 -0,1 Current A Cursor mm3/ms Q_kd l/hr: 1.31 DIESEL INJECTION QUANTITY MEASUREMENT AVL STS PLU 131 Diesel For diesel applications, the AVL Shot-to-Shot™ PLU 131 flow measurement system is used for the research, development and production of injectors, injection systems and corresponding combustion engines. The connection with the AVL indicating technology family IndiAdvanced offers convenient options for rate curve analysis as part of the indicating data collection. The timing analysis and the minimal quantity measurement in particular are very important measurement variables for multiple-injections during diesel combustion. MEASUREMENT PRINCIPLE In diesel applications, the system is used in downstream configuration on the low-pressure side of the injectors at up to 200 bar of counter pressure. The dual PLU measurement principle entails the combination of a rotatory and a translatory positive displacement meter. Using STS, you can determine the injection quantities precisely and also record the rate curves in high resolution. APPLICATION Diesel CR injectors are characterized on component benches regarding injection rate, injection quantity as well as open and closing delay times. Complete injection systems are pre-calibrated during the engine development procedure on the fully instrumented multiple-cylinder system testbed to save valuable development time and costs on the engine testbed at a later point in time. Renowned heavy duty vehicle manufacturers use STS to optimize their unit-injector fuel injection systems on full HD engine testbeds, for example. Within the framework of 100 % testing of the injector series production, STS satisfies the extreme requirements of a robust, fast shot quantity measurement with high accuracy. BENEFITS AT A GLANCE • Compliance with the emission limits through reliable characterization of the relevant parameters to control multiple-injection systems • Reduction of engine testbed development time for the calibration of injection systems due to pre-mapping of injection parameters on the injection system testbed • Cost efficiency of the production test due to short measurement times and robust measurement systems • High relevance due to large operating ranges for pressure and temperature which allow different loads and speeds to be measured under realistic conditions Diesel Downstream – Multiple-Injection Analysis: injection rate measurement of a typical CR diesel multiple injection sequence with pilot, main and post injections. Piezo injector current, piston sensor displacement and cursors for quantity measurement are seen below.
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