Intake Manifold Modeling for the Fuel Metering Control of Spark Ignited Engines

1997 ◽  
Vol 119 (3) ◽  
pp. 568-573
Author(s):  
S. Thompson ◽  
C. Gong

In order to minimize emissions the Air-Fuel Ratio (AFR) of a spark-ignited internal combustion engine needs to be maintained at stoichiometric. Whenever the air and fuel enter the engine’s cylinder the AFR cannot be changed; therefore the problem of AFR control is a problem of intake manifold control. Although the problem of AFR control (and hence of intake manifold modelling) appears to be solved for a fully warmed-up engine the problem of AFR control during the warm-up period remains. This paper addresses this problem by using a novel AFR control strategy, which can be based on a given intake manifold model, to test the AFR control of a partially warmed-up engine. The results of engine tests demonstrate that during the warm-up period tight AFR control is not possible using any of the intake manifold models developed for a fully warmed-up engine. This can only be the result of unmodeled dynamics in the intake manifold and it is therefore concluded that further work in the area of manifold modelling is required. Possible areas of model improvement are indicated.

Author(s):  
Michael R. Buchman ◽  
W. Brett Johnson ◽  
Amos G. Winter

Turbocharging can provide a cost effective means for increasing the power output and fuel economy of an internal combustion engine. A turbocharger added to an internal combustion engine consists of a coupled turbine and compressor. Currently, turbocharging is common in multi-cylinder engines, but it is not commonly used on single-cylinder engines due to the phase mismatch between the exhaust stroke (when the turbocharger is powered) and the intake stroke (when the engine intakes the compressed air). The proposed method adds an air capacitor, an additional volume in series with the intake manifold, between the turbocharger compressor and the engine intake, to buffer the output from the turbocharger compressor and deliver pressurized air during the intake stroke. This research builds on previous work where it was shown experimentally that a power gain of 29% was achievable and that analytically a power gain of 40–60% was possible using a turbocharger and air capacitor system. The goal of this study is to further analyze the commercial viability of this technology by analyzing the effect of air capacitor turbocharging on emissions, fuel economy, and power density. An experiment was built and conducted that looked at how air capacitor sizing affected emissions, fuel economy, and the equivalence ratio. The experimental data was then used to calibrate a computational model built in Ricardo Wave. Finally this model was used to evaluate strategies to further improve the performance of a single cylinder diesel turbocharged engine with an air capacitor.


2021 ◽  
Vol 1 (1) ◽  
pp. 51-56
Author(s):  
N.A. Ivanov ◽  
◽  
D.V. Otmakhov ◽  
S.P. Zakharychev ◽  
O.V. Kazannikov ◽  
...  

The main topic of the article is the development of an effective design for a pre-starting heating system for an internal combustion engine for conditions of limited power supply. The work to im-prove the design of light wheeled all-terrain vehicles on low pressure pneumatics is done at Pacific National University. Prototypes of light wheeled off-road vehicles are used mainly in agriculture and for forestry production. There are prerequisites for their use in oil and gas fields in the Far North conditions. This vehicle is operated all year round, in the absence of power supply, it is stored in the open air, so the problem of starting a cold engine is quite important, and the topic of creating a design for a pre-starting heating system for an internal combustion engine under conditions of limited or com-plete absence of power supply is relevant. The purpose of the work is to develop and study the efficiency of the pre-starting heating system for an internal combustion engine with liquid cooling for conditions of limited power supply. Our own design of the cooling system with a pre-starting heating function based on a gasoline burner was developed. To assess the efficiency of the engine warm-up process, the circuit was as-sembled on a light wheeled all-terrain vehicle. The experimental studies were carried out to deter-mine the regularity of changes in the temperature of the engine coolant during pre-starting heating at different ambient temperatures. The results of the experiment indicate the high efficiency of the developed system based on a gasoline burner. The average heating rate of the engine coolant during the warm-up process was 2.1 - 2.8 оС per minute, which indicates an intensive pace of pre-starting heating.


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