Active Identification Method for Line Resistance in DC Microgrid Based on Single Pulse Injection

2018 ◽  
Vol 33 (7) ◽  
pp. 5561-5564 ◽  
Author(s):  
Chen Liu ◽  
Jinbin Zhao ◽  
Shanshan Wang ◽  
Wu Lu ◽  
Keqing Qu
Keyword(s):  
Single Pulse ◽  
Dc Microgrid ◽  
Pulse Injection ◽  
Active Identification ◽  
Identification Method ◽  
Line Resistance

Effect of Fuel Injection Timing During Negative Valve Overlap Period on a GDI-HCCI Engine

2018 ◽  
Author(s):  
Sok Ratnak ◽  
Jin Kusaka ◽  
Yasuhiro Daisho ◽  
Kei Yoshimura ◽  
Kenjiro Nakama
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Single Pulse ◽  
Injection Timing ◽  
Pulse Injection ◽  
Hcci Combustion ◽  
Fuel Injection Timing ◽  
Intake Stroke ◽  
Negative Valve Overlap ◽  
Valve Overlap

Gasoline Direct Injection Homogeneous Charge Compression (GDI-HCCI) combustion is achieved by closing early the exhaust valves for trapping hot residual gases combined with direct fuel injection. The combustion is chemically controlled by multi-point auto-ignition which its main combustion phase can be controlled by direct injection timing of fuel. This work investigates the effect of single pulse injection timing on a supercharged GDI-HCCI combustion engine by using a four-stroke single cylinder engine with a side-mounted direct fuel injector. Injection of primary reference fuel PRF90 under the near-stoichiometric-boosted condition is studied. The fuel is injected during negative valve overlap (NVO) or recompression period for fuel reformation under low oxygen concentration and the injection is retarded to intake stroke for the homogeneous mixture. It is found that the early fuel injection in NVO period advances the combustion phasing compared with the retarded injection in the intake stroke. Noticeable slower combustion rate from intake stroke fuel injection is obtained compared with the NVO injection due to charge cooling effect. Zero-dimensional combustion simulations with multiple chemical reaction mechanisms are simulated to provide chemical understanding from the effect of fuel injection timing on intermediate species generations. The species such as C2H4, C3H6, CH4, and H2 are found to be formed during the NVO injection period from the calculations. The effects of single pulse injection timings on combustion characteristics such pressure rise rate, combustion stability, and emissions are also discussed in this study.

Comparison of Single and Multiple Injection Strategies in a Butanol Diesel Dual Fuel Engine

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Jaykumar Yadav ◽  
Asvathanarayanan Ramesh
Keyword(s):  
Pressure Rise ◽  
Single Pulse ◽  
Dual Fuel ◽  
Injection Timing ◽  
Brake Thermal Efficiency ◽  
Fuel Injectors ◽  
Pulse Injection ◽  
Brake Mean Effective Pressure ◽  
Energy Share ◽  
Injection Strategies

A turbocharged three cylinder automotive common rail diesel engine was modified to operate in the n-butanol diesel dual fuel mode. The quantity of butanol injected by the port fuel injectors and the rail pressure, injection timing, and number of injection pulses of diesel were varied using open engine controllers. Experiments were performed in the dual fuel mode at a constant speed of 1800 rpm at varying brake mean effective pressure (BMEPs). Butanol to diesel energy share was varied, and the injection timing of diesel was always set for highest brake thermal efficiency (BTE). Single pulse injection (SPI) and two pulse injection (TPI) of diesel were evaluated. In SPI, with increase in the butanol to diesel energy share, the BTE remained unchanged. At high loads and high amounts of butanol, the heat release rate (HRR) variation indicated that butanol auto ignited before diesel with both SPI and TPI of diesel. NO emission always decreased because of reduced temperatures due to evaporation of butanol. Butanol also reduced the smoke levels except at high loads. HC levels were always higher. With optimized injection parameters, TPI of diesel resulted in lower NO, similar smoke, and BTE with lesser rate of pressure rise as compared to SPI of diesel in the dual fuel mode at high loads. On the whole, the SPI mode is suitable for low to medium outputs and the TPI mode is suitable for high outputs.

scholarly journals High-extraction-efficiency, nanosecond bidirectional ring amplifier with twin pulses

2019 ◽  
Vol 7 ◽  
Author(s):  
Tiancheng Yu ◽  
Jiangtao Guo ◽  
Gang Xia ◽  
Xiang Zhang ◽  
Fan Gao ◽  
...  
Keyword(s):  
Extraction Efficiency ◽  
Single Pulse ◽  
High Energy ◽  
Operating Conditions ◽  
Maximum Output ◽  
Stored Energy ◽  
Pulse Injection ◽  
Potential Applications ◽  
Energy Laser ◽  
Bidirectional Propagation

The output performances of a bidirectional ring amplifier with twin pulses are demonstrated. Compared to the extraction efficiency of 32% for single-pulse injection, the extraction efficiency of stored energy for twin-pulse injection with bidirectional propagation is increased to 60%. The maximum output energies of the twin pulses are 347 mJ and 351 mJ, and the output energy of a single pulse is only 373 mJ under the same amplifier operating conditions. The experimental results show that the bidirectional ring amplifier with twin pulses can achieve a higher extraction efficiency of stored energy at a lower operating fluence, and has potential applications in high-power and high-energy laser facilities.

Comparison of Single and Multiple Injection Strategies in a Butanol Diesel Dual Fuel Engine

2017 ◽  
Author(s):  
Jaykumar Yadav ◽  
Asvathanarayanan Ramesh
Keyword(s):  
Pressure Rise ◽  
Single Pulse ◽  
Dual Fuel ◽  
Rate Variation ◽  
Injection Timing ◽  
Brake Thermal Efficiency ◽  
Fuel Injectors ◽  
Pulse Injection ◽  
Energy Share ◽  
Injection Strategies

A turbocharged three cylinder automotive common rail diesel engine was modified to operate in the n-butanol diesel dual fuel mode. The quantity of butanol injected by the port fuel injectors and the rail pressure, injection timing and number of injection pulses of diesel were varied using open engine controllers. Experiments were performed in the dual fuel mode at a constant speed of 1800 rpm at varying BMEPs. Butanol to diesel energy share (BDES) was varied and the injection timing of diesel was always set for highest brake thermal efficiency (BTE). Single pulse injection (SPI) and two pulse injection (TPI) of diesel were evaluated. In SPI with increase in butanol diesel energy share (BDES), BTE remained unchanged. At high loads and high BDES the heat release rate variation indicated that butanol auto ignited before diesel with both SPI and TPI of diesel. NO emission always decreased because of reduced temperatures due to evaporation of butanol. Butanol also reduced the smoke levels except at high loads. HC levels were always higher. With optimized injection parameters TPI of diesel resulted in lower NO, similar smoke and BTE with lesser rate of pressure rise as compared to SPI of diesel.

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