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Energy aspects of the SI engine load adjustment by early closing of inlet or exhaust valve

Żmudka Z., Postrzednik S., Przybyła G.

Journal of KONES

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2016

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Vol. 23, No. 4

583--590

EN

The theoretical analysis of the SI engine load adjustment has been presented. The load especially in SI engine is highly dependent on the process of charge exchange. This process has significant impact on the effectiveness of an engine work because it is connected with the necessity of overcoming the flow resistance, then with the necessity of doing a work, so-called the charge exchange work. The flow resistance caused by throttling valve is especially high during part load operation. The open theoretical cycle has been assumed as a model of processes proceeding in the engine. Using fully variable inlet and exhaust valves timing the cycle can be realized e.g. according to two systems: system with early inlet valve closing (EIVC) and system with early exhaust valve closing (EEVC). Both systems have been analysed individually and comparatively with the open Seiliger-Sabathe cycle, which is theoretical cycle for the classical throttle governing of an engine load. Benefits resulting from application of the systems with independent inlet and exhaust valves control have been assessed on the basis of the selected parameters: a fuel dose, a cycle work, a charge exchange work and a cycle efficiency. The use of the analysed systems to governing of the SI engine load will enable to eliminate a throttling valve from inlet system and reduce the charge exchange work, especially within the range of part load operation. Decrease of the charge exchange work leads to increase of the internal and effective works, which results in increase of the effective efficiency of the spark ignition engine. Additionally, the EEVC enables realization of the internal EGR.

2

Realization of the Atkinson-Miller cycle in spark-ignition engine by means of the fully variable inlet valve control system

Żmudka Z., Postrzednik S., Przybyła G.

Archives of Thermodynamics

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2014

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Vol. 35, no. 3

191--205

EN

The theoretical analysis of the charge exchange process in a spark ignition engine has been presented. This process has significant impact on the effectiveness of engine operation because it is related to the necessity of overcoming the flow resistance, followed by the necessity of doing a work, so-called the charge exchange work. The flow resistance caused by the throttling valve is especially high during the part load operation. The open Atkinson-Miller cycle has been assumed as a model of processes taking place in the engine. Using fully variable inlet valve timing the A-M cycle can be realized according to two systems: system with late inlet valve closing and system with early inlet valve closing. The systems have been analysed individually and comparatively with the open Seiliger-Sabathe cycle which is a theoretical cycle for the classical throttle governing of the engine load. Benefits resulting from application of the systems with independent inlet valve control have been assessed on the basis of the selected parameters: fuel dose, cycle work, charge exchange work and a cycle efficiency. The use of the analysed systems to governing of the SI engine load will enable to eliminate a throttling valve from the system inlet and reduce the charge exchange work, especially within the range of part load operation.

3

Charge exchange control in a SI engine by early exhaust valve closing

Żmudka Z., Postrzednik S., Przybyła G.

Journal of KONES

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2013

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Vol. 20, No. 1

387--394

EN

The paper tackles the problems connected with the charge exchange in internal combustion engines. The theoretical analysis of the charge exchange process in the SI engine has been presented. A system with independent, early exhaust valve closing has been analysed. The analysed system enables realization of an internal EGR and elimination of a throttling valve from an inlet system and reduce the charge exchange work, especially within the range of partial load. The decrease of the charge exchange work leads to an increase of the internal and effective works, which results in an increase of the effective efficiency of the spark ignition engine. The open, theoretical cycle has been assumed as a model of processes proceeding in an engine. The system has been analysed individually and comparatively with open Seiliger-Sabathe cycle. Benefits resulting from application of the system with early exhaust valve closing have been assessed on the basis of the selected parameters: a fuel dose, a cycle work, a relative charge exchange work and a cycle efficiency. The best results within decrease of fuel consumption and increase of cycle efficiency are obtained for low engine load. The main parameters characterizing the process of the internal exhaust gas recirculation were also determined. These are the ratio and the multiplicity of the exhaust gas recirculation.

4

Analiza efektywności niezależnego sterowania zaworami wylotowymi jako sposobu realizacji wewnętrznej recyrkulacji spalin

Żmudka Z., Postrzednik S., Przybyła G.

Combustion Engines

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2013

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R. 52, nr 3

338--345

PL

Przeprowadzono analizę systemu z niezależnym, wcześniejszym zamknięciem zaworu wylotowego, który umożliwia realizację wewnętrznej recyrkulacji spalin oraz wyeliminowanie przepustnicy w silniku ZI. Odniesieniem dla oceny korzyści oraz badania efektywności pozyskiwania pracy, w wyniku zastosowania tego systemu sterowania, jest otwarty obieg teoretyczny Seiligera-Sabathe’a z powszechnie stosowaną klasyczną regulacją dławieniową obciążenia. Analizę porównawczą efektywności zastosowania zaproponowanego systemu przeprowadzono opierając się na wybranych wielkościach: dawce paliwa, pracy obiegu, względnej pracy wymiany ładunku oraz sprawności obiegu. Najlepsze efekty w zakresie zmniejszenia dawki paliwa i zwiększenia sprawności obiegu dla analizowanego systemu, w porównaniu do systemu z regulacją dławieniową, uzyskuje się w obszarze średniego obciążenia silnika.

EN

A system with independent, early exhaust valve closing has been analysed. The analysed system enables realization of an internal EGR and elimination of a throttling valve from inlet system of a spark ignition engine. The open, theoretical cycle has been assumed as a model of processes proceeding in an engine. The system has been analysed individually and comparatively with open Seiliger-Sabathe cycle. Benefits resulting from application of the system with early exhaust valve closing have been assessed on the basis of the selected parameters: a fuel dose, a cycle work, a relative charge exchange work and a cycle efficiency. The best results within decrease of fuel consumption and increase of cycle efficiency are obtained for mean engine load.