Hydraulic Interactions between Injection Events Using Multiple Injection Strategies and a Solenoid Diesel Injector

Abstract

An experimental study was performed to explore the influence of dwell time on the hydraulic interactions between injection events using pilot injection strategy, split injection strategy, post injection strategy and a solenoid diesel injector. To do so, a sweep of dwell time from 0.55 up to 2 ms using all multiple injection strategies and levels of rail pressure, of 80, 100 and 120 MPa, and single level of back pressure, of 5 MPa, was performed. The hydraulic interactions between injection events were characterized through the second injection hydraulic delay and second injection mass in an injection discharge curve indicator equipped with all the components required for its operation and control. In order to define the operating conditions of the multiple injection strategies, to ensure the same injected fuel mass in all cases, the characteristic curves of injection rate for the solenoid diesel injector studied were obtained. The second injection hydraulic delay increases with dwell time values in the range of 0.55–0.9 ms for all multiple injection strategies and levels of rail pressure tested. Conversely, the second injection hydraulic delay decreases with dwell time values higher than 0.9 ms. Moreover, the second hydraulic delay depends mainly on the dwell time and not on the injected fuel mass during the first injection event. The second injection mass increases with dwell values less than 0.6 ms. By contrast, the second injection mass is not significantly affected by that of the first injection at a dwell time higher than 0.6 ms.

Effect of the Air Flow on the Combustion Process and Preheating Effect of the Intake Manifold Burner

“…Diesel engine still faces enormous challenges to meet the requirements of worldwide environmental problems and human health. In order to obtain better engine performance, different methods such as split injection strategy [2,3], biodiesel [4], emulsified fuels [5], and oxygen-enriched combustion [6] have been used to improve the spray breakup, combustion efficiency, and emissions. Though improved by various methods, the emission and performance of diesel engines under the sub-zero environment remains a critical problem.…”

Analysis of potential improvements in the performance of solenoid injectors in diesel engines

“…A review of the literature [8,18,32,33] The heat transfer coefficient σ was calculated with the use of equation (1) to account for the presence of a leakage flux in the magnetic circuit:…”

“…They analyzed hydraulic processes in the injector, but disregarded electromagnetic phenomena in the coil, which also play an important role in injector performance. In turn, Martínez-Martínez et al [18] analyzed the amount of injected fuel at different dwell times between injection pulses. They concluded that dwell times between successive electric pulses significantly influence the amount of delivered fuel.…”

Characterization of the Rate of Injection of Diesel Solenoid Injectors Operated in the Multiple Injection Strategy: A Comparison of the Spray Momentum and Bosch Tube Methods

“…When measuring the ROI, it is more accurate to reproduce as much as possible engine-like conditions (AlRamadan et al, 2019;Aljohani et al, 2019). The choice of the ROI measurement methodology is critical, particularly for multiple injection schemes (Martínez-Martínez et al, 2021). For instance, the spray momentum method could not characterize the ROI of short early injections as demonstrated in AlRamadan et al (2019).…”