Comparison of Sensor Configurations for Mass Flow Estimation of Turbocharged Diesel Engines

Author(s):  
Tomáš Polóni ◽  
Boris Rohal’-Ilkiv ◽  
Daniel Alberer ◽  
Luigi del Re ◽  
Tor Arne Johansen
Author(s):  
Manuel A. Borregales ◽  
Gilberto Nuñez ◽  
Jose Cappelletto ◽  
Miguel Asuaje

Due to depletion of on-shore and superficial oil reservoirs, and impulsed by recent discoveries of oil reservoirs in off-shore ultra-deep waters, each of the processes and equipment in oil production required further improvements in order to save costs, space and to reduce weight off-shore. One way to accomplish this is without separators and with the use of online multiphase flowmeters. The most used flowmeter is the Venturi tube. Despite Venturi flowmeters having been used in almost all commercial multiphase flowmeters, there is not a single correlation that provides good results for predicting mass flow in each phase, for any flow pattern, mass quality, void fraction and/or fluids properties. Instead, many correlations have been published, based on experimental and/or field data, but the use of these correlations outside multiphase range conditions is doubtful. This study proposes a new methodology that uses genetic algorithms to find correlations that better fit a set of data, which allow determining the mass flow of a two-phase mix through a Venturi tube. For that purpose, binary trees and Prüfer encoding are used to accomplish this implementation. The correlations found in this new methodology provide lower values of RMS error, 1–3%, against correlations proposed by previous authors that show an RMS error range of 5–10%. This technique allows finding further correlations, regardless the number of parameters to be used, at a low computational cost, and it does not require previous information on the behaviour of the data.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1287
Author(s):  
Salah A.M. Elmoselhy ◽  
Waleed F. Faris ◽  
Hesham A. Rakha

The flexibility of a crankshaft exhibits significant nonlinearities in the analysis of diesel engines performance, particularly at rotational speeds of around 2000 rpm. Given the explainable mathematical trends of the analytical model and the lack of available analytical modeling of the diesel engines intake manifold with a flexible crankshaft, the present study develops and validates such a model. In the present paper, the mass flow rate of air that goes from intake manifold into all the cylinders of the engine with a flexible crankshaft has been analytically modeled. The analytical models of the mass flow rate of air and gas speed dynamics have been validated using case studies and the ORNL and EPA Freeway standard drive cycles showing a relative error of 7.5% and 11%, respectively. Such values of relative error are on average less than those of widely recognized models in this field, such as the GT-Power and the CMEM, respectively. A simplified version for control applications of the developed models has been developed based on a sensitivity analysis. It has been found that the flexibility of a crankshaft decreases the mass flow rate of air that goes into cylinders, resulting in an unfavorable higher rate of exhaust emissions like CO. It has also been found that the pressure of the gas inside the cylinder during the intake stroke has four elements: a driving element (intake manifold pressure) and draining elements (vacuum pressure and flow losses and inertial effect of rotating mass). The element of the least effect amongst these four elements is the vacuum pressure that results from the piston's inertia and acceleration. The element of the largest effect is the pressure drop that takes place in the cylinder because of the air/gas flow losses. These developed models are explainable and widely valid so that they can help in better analyzing the performance of diesel engines.


2016 ◽  
Author(s):  
Zhijia Yang ◽  
Edward Winward ◽  
Gary O'Brien ◽  
Richard Stobart ◽  
Dezong Zhao

2013 ◽  
Vol 46 (2) ◽  
pp. 731-736 ◽  
Author(s):  
F. Castillo ◽  
E. Witrant ◽  
V. Talon ◽  
L. Dugard

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