Investigation of the thermal effects of fuel injection into retained residuals in HCCI engine

Hunicz, Jacek; Mikulski, Maciej

doi:10.1016/j.apenergy.2018.07.075

Cited by 25 publications

(20 citation statements)

References 52 publications

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“…The temperature of cooling liquid at the engine outlet is maintained constant at 90 ± 1 °C. The fuel is introduced into the cylinder at strategically selected start of injection (SOI) timings, which functions were verified in our previous works [14][15][16]. To enable fuel reforming, the NVO injection is applied at SOI = 660°.…”

Section: Experimental Conditions and Proceduresmentioning

confidence: 88%

“…A detailed description of the engine and the valvetrain is presented in refs. [14,15]. At this point only a concise decryption of the functionalities relevant to the present tests are provided.…”

Section: Experimental Approach 21 Research Engine and Test Standmentioning

confidence: 99%

“…The set points of  and boost pressure are adjusted to optimal conditions for a given load case. Those settings were determined in previous research endeavours as the best trade-offs between efficiency and NOx emissions [14,15]. Note that the valve settings used to achieve NVO in the present study are not per-case optimized.…”

Section: Experimental Conditions and Proceduresmentioning

confidence: 99%

“…Aside of the above chemical effects of fuel reforming, thermal effects of NVO injection can be used for combustion phasing control across all the engine operating conditions [14,15]. Note however that the effects highly depend on NVO injection timing and mixture strength.…”

Section: Introductionmentioning

confidence: 99%

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HCCI combustion control using advanced gasoline direct injection techniques

Hunicz

Mikulski²,

Komsta

2018

MATEC Web Conf.

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Homogeneous Charge Compression Ignition (HCCI) is a promising low temperature combustion technology for reciprocating engines that offers high fuel efficiency and extremely low exhaust emissions. However, combustion control should be improved and operating range should be widened for the technology to achieve production level. In this study an overview of different direct gasoline injection control approaches, applied to improve stability at low engine loads and to reduce pressure rise rates at high load regime, is presented. The tests are performed on a single-cylinder research engine operated in a negative valve overlap (NVO) mode for residual gasses trapping. The investigated direct injection schemes included: (i) fuel injection during the NVO period to improve mixture reactivity and take an advantage of exhaust-fuel reactions thermal effects, (ii) fuel injection during intake stroke to create homogeneous charge and (iii) late fuel injection during compression stroke to create stratified charge. The results showed that application of early NVO injection enables active control of combustion timing at nearly idle conditions. The late fuel injection, during the compression stroke, enabled mitigation of excessive pressure rise rates at high engine load regime.

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Section: Experimental Conditions and Proceduresmentioning

confidence: 88%

Section: Experimental Approach 21 Research Engine and Test Standmentioning

confidence: 99%

Section: Experimental Conditions and Proceduresmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

HCCI combustion control using advanced gasoline direct injection techniques

Hunicz

Mikulski²,

Komsta

2018

MATEC Web Conf.

Self Cite

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“…Recent work by Hunicz and Mikulski [4] has shown that PRR can be effectively controlled via variation in mass of fuel injected during the NVO period for reforming. This technique enabled effective control of fuel reactivity [5] and also provided the substantial thermal effects [6].…”

Section: Introductionmentioning

confidence: 99%

Effects of combustion timing on pressure rise rates in a residual effected HCCI engine

et al. 2019

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Realization of a low temperature combustion concept in homogeneous charge compression ignition (HCCI) engines is a cutting-edge technology that offers clean combustion in parallel with high thermal efficiency. Low combustion temperature prevents from NOx for-mation whereas homogeneous mixture assures smokeless exhaust. However, achieving the production feasibility by HCCI technology is hampered by high pressure rise rates and the resulting combustion noise at a high load operation. This paper explores combustion tim-ing parameters that are capable of maintaining permissible levels of pressure rise rates under a high load regime. On the basis of exper-imental data collected at a high load HCCI operation, pressure rise level was correlated with combustion duration. Furthermore, com-bustion duration has been found to scale with in-cylinder volume, for which 50% of mass fraction burned appeared. The results showed quantitatively limitations of engine load, pointing out on required combustion timings to achieve acceptable combustion harshness de-pending on engine load.

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Effect of internal exhaust gas recirculation on performance, combustion, and emissions in a PFI camless engine

Tripathy

Srivastava

2022

Env Prog and Sustain Energy

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The internal exhaust gas recirculation (EGR) into the intake manifold has a significant impact on fuel economy and emissions in the spark ignition (SI) engine. In this study, an in-house developed novel electro-pneumatic variable valve actuation (VVA) system was integrated on a PFI conventional engine and modified into PFI camless engine to vary the valve events independently. The potential of the developed VVA system in achieving the internal EGR by varying the intake valve opening (IVO) timings was widely investigated. The IVO timing was varied from 30 CA (crank angle) bITDC (before intake top dead center) to 40 CA aITDC (after intake top dead center). The spark timing was varied from 10 to 30 CA bCTDC (before compression top dead center). A 41% pumping mean effective pressure reduction was achieved with varying the IVO from 40 to À30 CA aITDC. It is due to the internal exhaust gas recirculation into the intake manifold that reduces the differential pressure between the manifold and combustion chamber. The entrapment of exhaust gas in the intake manifold dilutes the fresh charge, which deteriorates the combustion.However, advancing the spark timing from 10 to 30 CA bCTDC at IVO À30 CA aITDC, an 18% gas excahnge efficiency improvement was obtained. The fresh charge dilution forms an inhomogeneous mixture inside the cylinder that results in lower NO x emission. It is concluded that the developed VVA system has the potential to improve part loads efficiency by utilizing the internal EGR in a PFI camless engine.

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Investigation of the thermal effects of fuel injection into retained residuals in HCCI engine

Cited by 25 publications

References 52 publications

HCCI combustion control using advanced gasoline direct injection techniques

HCCI combustion control using advanced gasoline direct injection techniques

Effects of combustion timing on pressure rise rates in a residual effected HCCI engine

Effect of internal exhaust gas recirculation on performance, combustion, and emissions in a PFI camless engine

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