Fuel Economy Benefit of Cylinder Deactivation - Sensitivity to Vehicle Application and Operating Constraints

Author(s):  
T. G. Leone ◽  
M. Pozar
2020 ◽  
Vol 83 (2/3/4) ◽  
pp. 258
Author(s):  
Levent Guvenc ◽  
Bilin Aksun Guvenc ◽  
Ozgenur Kavas Torris ◽  
Mustafa Ridvan Cantas ◽  
Sukru Yaren Gelbal

Author(s):  
Michael McGhee ◽  
Ziman Wang ◽  
Alexander Bech ◽  
Paul J Shayler ◽  
Dennis Witt

The changes in thermal state, emissions and fuel economy of a 1.0-L, three-cylinder direct injection spark ignition engine when a cylinder is deactivated have been explored experimentally. Cylinder deactivation improved engine fuel economy by up to 15% at light engine loads by reducing pumping work, raising indicated thermal efficiency and raising combustion efficiency. Penalties included an increase in NOx emissions and small increases in rubbing friction and gas work losses of the deactivated cylinder. The cyclic pressure variation in the deactivated cylinder falls rapidly after deactivation through blow-by and heat transfer losses. After around seven cycles, the motoring loss is ~2 J/cycle. Engine structural temperatures settle within an 8- to 13-s interval after a switch between two- and three-cylinder operation. Engine heat rejection to coolant is reduced by ~13% by deactivating a cylinder, extending coolant warm-up time to thermostat-opening by 102 s.


2021 ◽  
Author(s):  
Salvio Chacko ◽  
Dimitri Kalifronas ◽  
Jesus Simon ◽  
Carlos Alonso ◽  
Antonio Solimene

2020 ◽  
Author(s):  
Dong Hyeong Lee ◽  
Dojoong Kim ◽  
Wan Jae Jeon ◽  
Yong Seok Hong ◽  
Jong Wung Park

2011 ◽  
Vol 145 ◽  
pp. 83-87 ◽  
Author(s):  
Yao Jung Shiao ◽  
Ly Vinh Dat

In this paper, an unthrottled camless engine model, which equipped electromagnetic valvetrain (EMV), has been built for performance simulation of engine dynamics. The combination of the techniques of cylinder deactivation (CDA) and variable valve timing (VVT) has been examined for different engine speeds and engine loads. The results concluded that the mode of two-cylinder deactivation considerably improves the fuel consumption at low engine load. Meanwhile, the one-cylinder deactivation mode is an optimal fuel economy mode for medium engine load. The normal engine mode fairly satisfies the driving torque and fuel economy in a vehicle, and thus it fits the optimal mode for the full loads. Additionally, the results also show that the optimal intake valve closing (IVC) timing for different engine speeds and loads. The IVC timing depends on engine speed linearly while the optimal IVC timing insignificantly changes at different engine loads when CDA is applied. By the determined CDA-VVT strategy, a camless unthrottled engine can maintain high efficiency operation for different speeds and loads.


Author(s):  
Marc Ross ◽  
Alberto J. Lo´pez ◽  
Frank H. Walker

Half the engine displacement of popular cars and light trucks would be adequate for most driving. The split engine (SE) is introduced here as a concept to improve the fuel economy of light-duty vehicles with large spark-ignition internal combustion engines. It operates with a small-displacement portion of the engine for typical driving and activates the secondary portion of the engine to assist with high-power driving. SE is different from cylinder deactivation; the two portions of the engine have independent crankshafts which connect through a one-way clutch, a mechanical diode with indexing features to achieve the correct relative phase of the engine sections. For illustration, 6- and 8-cylinder SE are proposed and simple versions are modeled analytically. The 6-cylinder SE consists of two inline 3-cylinder engines of equal or near-equal displacement. The 8-cylinder SE consists of two opposed horizontal 4-cylinder engines of the same displacement. SE and cylinder deactivation are also compared. Moments of inertia and the time to connect both engine sections smoothly are estimated. Fuel economy improvements with SE are estimated for the EPA urban and highway cycles.


Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3084
Author(s):  
Nankyu Lee ◽  
Jinil Park ◽  
Jonghwa Lee ◽  
Kyoungseok Park ◽  
Myoungsik Choi ◽  
...  

Cylinder deactivation is a fuel economy improvement technology that has attracted particular attention recently. The currently produced cylinder deactivation engines utilize fixed-type cylinder deactivation in which only a fixed number of cylinders are deactivated. As fixed-type cylinder deactivation has some shortcomings, variable-type cylinder deactivation with no limit on the number of deactivated cylinders is under research. For variable-type cylinder deactivation, control is more complicated and production cost is higher than fixed-type cylinder deactivation. Therefore, it is necessary to select the cylinder deactivation control method considering both advantages and disadvantages of the two control methods. In this study, a fuel economy prediction simulation model was created using the measurement data of various vehicles with engine displacements of 1.0–5.0 L. The fuel economy improvement of fixed-type cylinder deactivation was compared with that of variable-type cylinder deactivation using the created simulation. As a result of examining the fuel economy improvement of the test vehicle in the FTP-75 driving cycle, the improvement was 2.2–10.0% for fixed-type cylinder deactivation and 2.2–12.8% for variable-type cylinder deactivation. Furthermore, the effect of the engine load on fuel economy improvement under cylinder deactivation and the effect of changes in engine control were examined via a simulation.


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