Study on Effects of Common Rail Injector Drive Circuitry with Different Freewheeling Circuits on Control Performance and Cycle-by-Cycle Variations

Liu, Erxi; Su, Weifeng

doi:10.3390/en12030564

Cited by 4 publications

(8 citation statements)

References 15 publications

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“…where = X f,i (t), = u i (t) are the fuel volume fraction and fluid velocity averaged over the spray cross section at i − th control volume respectively, ρ f is the fuel density, β i is the coefficient which determines the radial velocity profile at i − th control volume, A i is the cross-sectional area at the downstream surface of i − th control volume, = ρ i (t) is the cross-section averaged fluid density at i − th control volume. A i , = X f,i (t), = u i (t) and = ρ i (t) are given by the Equations (5)- (8) respectively: align these symbols…”

Section: Spray Modelmentioning

confidence: 99%

“…To cope with the emission problem and improve the performance of diesel engines, the common rail technology has flourished around the world. The advanced fuel injection technologies in a common rail system, such as the ultrahigh injection pressure [1][2][3][4] and the multiple-injection strategy [5][6][7] as well as the high control accuracy [8], have greatly improved the performance of diesel engines. Under the action of ultrahigh injection pressures, the fuel can be injected into the cylinder in a short time, while the multiple-injection strategy divides the whole injection duration into many parts, creating shorter injection durations.…”

Section: Introductionmentioning

confidence: 99%

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Investigation on an Injection Strategy Optimization for Diesel Engines Using a One-Dimensional Spray Model

2019

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Common rail systems have been widely used in diesel engines due to the stricter emission regulations. The advances in injector technology and ultrahigh injection pressure greatly promote the development of multiple-injection strategy, leading to the shorter injection duration and more variable injection rate shape, which makes the mixing process more significant for the formation of pollutant emission. In order to study the mixing process of diesel sprays under variable injection rate shapes and find the optimized injection strategy, a one-dimensional spray model was modified in this paper. The model was validated by the measured spray penetrations based on shadowgraphy experiments with the varying injection rate. The simulations were performed with five injection rate shapes, triangle, ramping-up, ramping-down, rectangle and trapezoid. Their spray penetrations, entrainment rates and equivalence ratios along spray axial distance are compared. The potentials of multiple-injection and gas-jet after end-of-injection (EOI) to improve mixing process and emission reduction are discussed finally. The results indicated that ramping-up injection rate obtains the highest entrainment rate after EOI, and it needs 1.5 times of injection duration for the entrainment wave to arrive at the spray tip. For the other four injection rates, the sprays can be treated as a steady-like state, needing twice of injection duration from EOI to the time the entrainment wave reaches the spray tip. The multiple-injection with proper injection rate shape enhanced the entrainment rate, and the gas-jet after EOI affected the mixture distribution and entrainment rate in spray tail under ramping-down injection rate.

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Section: Spray Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Investigation on an Injection Strategy Optimization for Diesel Engines Using a One-Dimensional Spray Model

2019

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“…Lu et al designed a variable drive system that could be used to comprehensively study the effects of different control strategies (driving voltage, opening and closing strategies and supply voltage) on the opening and closing delays of injection events with a high-speed imaging system [28]. Liu et al designed a variable-freewheeling circuit that exhibited a higher control accuracy, lower electric energy consumption and less heat release than those of the RD freewheeling circuit [29]. The most common peak and hold current control circuit is shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

“…The solution in Fig. 3 (c) efficiently minimizes the closing delay and recovers the freewheeling energy [28] since the freewheeling circuit changes during the different driving phases; this system is also called variable freewheeling [29]. Previous solutions addressed high-and low-side drives with high-side modulation, and the solutions for low-side drives are shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

“…There are three forms: entirely or partially relying on high-performance multi-core microcontrollers with high-speed analogues to digital conversion, with all control logic performed in the microcontrollers, such as Infineon's solution with the TriCore derivative TC1775 [21], [22]; and using applicationspecific integrated circuits controlled by serial peripheral interface (SPI) communication, such as chip L99SD01-E of STMicroelectronics [20]. The latter is built with discrete components and controlled by the analogue injection signal [28], [29].…”

Section: Introductionmentioning

confidence: 99%

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Drive Control Simulation and Experimental Studies on the Flow Characteristics of a Pump Injector

Wei

et al. 2020

IEEE Access

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As a miniaturized direct injection (DI) solution, the pump injector is of great significance for small aviation piston engines, such as two-stroke heavy-fuel engines. The accurate control of the timing and amount of injections is an important application prerequisite. In this paper, the flow characteristics of a pump injector with different driving circuits and parameters are investigated. The effects of the power supply and freewheeling circuits on the opening and closing delays are theoretically studied. A schematic of a self-designed logic control circuit is proposed, and it achieves peak and hold current control without software intervention. Simulations and experiments are carried out, and the drive current and flow characteristics in different states are measured. The results show that when driving a solenoid with a high internal resistance of 2.70 , a single power supply is more suitable, and the variable-freewheeling circuit exhibits excellent performance in terms of control accuracy and energy recovery. Notably, the invariable-freewheeling circuit results in nonlinear flow characteristics, and the nonlinear segment corresponds to the drive current transitioning from the peak value to the hold value. In contrast, the variable-freewheeling circuit overcomes this problem. To comprehensively consider solenoid opening and closing delays, energy consumption and the linearity of the flow characteristics during injection, a peak current of 10 A and a hold current of 8 A are adopted. INDEX TERMS Aviation aircrafts, direct injection, flow characteristics, peak and hold drive, piston engine, pump injector.

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Experimental Investigations of Injection and Combustion Parameters of a Homogeneous Charge Compression Ignition (HCCI) Engine with a Multi-Injection Common Rail System

Niklawy¹,

Shahin²,

Amin³

et al. 2022

Komunikácie

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This work experimentally investigates the most imperative parameters that control the injection and combustion processes in a multi-injection HCCI Diesel engine namely; fuel-line pressure, timing of multi-injection events and the resulting in-cylinder pressure. These parameters in addition to the heat release rates are evaluated at different engine loads and speeds over up to 42 successive cycles. The main inter-relations of these parameters are also discussed. Results revealed that the maximum cylinder pressure and temperature in the HCCI engines are lower by 7% compared to similar conventional ones, which could lead to lower NOx emission. In addition, the fuel line pressure exhibits nearly the same major frequency of the waves, 850 to 950 Hz. Those results could be very useful for engine assessment, modeling, control, NOx reduction and power saving.

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Study on Effects of Common Rail Injector Drive Circuitry with Different Freewheeling Circuits on Control Performance and Cycle-by-Cycle Variations

Cited by 4 publications

References 15 publications

Investigation on an Injection Strategy Optimization for Diesel Engines Using a One-Dimensional Spray Model

Investigation on an Injection Strategy Optimization for Diesel Engines Using a One-Dimensional Spray Model

Drive Control Simulation and Experimental Studies on the Flow Characteristics of a Pump Injector

Experimental Investigations of Injection and Combustion Parameters of a Homogeneous Charge Compression Ignition (HCCI) Engine with a Multi-Injection Common Rail System

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