Fuel consumption and aftertreatment thermal management synergy in compression ignition engines at variable altitude and ambient temperature

New regulations applied to the transportation sector are widening the operation range where the pollutant emissions are evaluated. Besides ambient temperature, the driving altitude is also considered to reduce the gap between regulated and real-life emissions. The altitude effect on the engine performance is usually overcome by acting on the turbocharger control. The traditional strategy assumes to keep (or even to increase) the boost pressure, that is, compressor pressure ratio increase, as the altitude is increased to offset the ambient density reduction, followed by the reduction of the exhaust gas recirculation to reach the targeted engine torque. However, this is done at the expense of an increase on fuel consumption and emissions. This work remarks experimentally the importance of a detailed understanding of the effects of the boost pressure and low-pressure exhaust gas recirculation (LP-EGR) settings when the engine runs low partial loads at different altitudes, accounting for extreme warm and cold ambient temperatures. The experimental results allow defining and justifying clear guidelines for an optimal engine calibration. Opposite to traditional strategies, a proper calibration of the boost pressure and LP-EGR enables reductions in specific fuel consumption along with the gas temperature increase at the exhaust aftertreatment system.

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Ensuring Requirements for Emissions of Harmful Substances of Diesel Engines

Science & Technique ◽

10.21122/2227-1031-2020-19-4-305-310 ◽

2020 ◽

Vol 19 (4) ◽

pp. 305-310

Author(s):

G. M. Kuharonak ◽

D. V. Kapskiy ◽

V. I. Berezun

Keyword(s):

Diesel Engine ◽

Nitrogen Oxides ◽

Fuel Consumption ◽

Exhaust Gas Recirculation ◽

Exhaust Gas ◽

Average Temperature ◽

Dispersed Particles ◽

Harmful Substances ◽

Gas Recirculation ◽

Emissions Of Harmful Substances

The purpose of this work is to consider the requirements for emissions of harmful substances of diesel engines by selecting design and adjustment parameters that determine the organization of the workflow, and the exhaust gas cleaning system, taking into account the reduction of fuel consumption. Design elements and geometric characteristics of structures for a turbocharged diesel engine of Д-245 series produced by JSC HMC Minsk Motor Plant (4ЧН11/12.5) with a capacity of 90 kW equipped with an electronically controlled battery fuel injection have been developed: exhaust gas recirculation along the high pressure circuit, shape and dimensions of the combustion chamber, the number and angular arrangement of the nozzle openings in a nozzle atomizer, and inlet channels of the cylinder head. Methods for organizing a workflow are proposed that take into account the shape of the indicator diagrams and affect the emissions of nitrogen oxides and dispersed particles differently. Their implementation allows us to determine the boundary ranges of changes in the control parameters of the fuel supply and exhaust gas recirculation systems when determining the area of minimizing the specific effective fuel consumption and the range of studies for the environmental performance of a diesel engine. The paper presents results of the study on the ways to meet the requirements for emissions of harmful substances, obtained by considering options for the organization of working processes, taking into account the reduction in specific effective fuel consumption, changes in the average temperature of the exhaust gases and diesel equipment. To evaluate these methods, the following indicators have been identified: changes in specific fuel consumption and average temperature of the toxicity cycle relative to the base cycle, the necessary degree of conversion of the purification system for dispersed particles and NOx. Recommendations are given on choosing a diesel engine to meet Stage 4 emission standards for nitrogen oxides and dispersed particles.

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Switching strategy between HP (high pressure)- and LPEGR (low pressure exhaust gas recirculation) systems for reduced fuel consumption and emissions

Energy ◽

10.1016/j.energy.2015.06.138 ◽

2015 ◽

Vol 90 ◽

pp. 1790-1798 ◽

Cited By ~ 18

Author(s):

José Manuel Luján ◽

Carlos Guardiola ◽

Benjamín Pla ◽

Alberto Reig

Keyword(s):

High Pressure ◽

Fuel Consumption ◽

Exhaust Gas Recirculation ◽

Low Pressure ◽

Exhaust Gas ◽

Switching Strategy ◽

Gas Recirculation ◽

Fuel Consumption And Emissions

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ЗАСТОСУВАННЯ ГАЗОДИНАМІЧНОГО ОХОЛОДЖЕННЯ В СИСТЕМАХ РЕЦИРКУЛЯЦІЇ ВІДХІДНИХ ГАЗІВ СУДНОВИХ ДИЗЕЛІВ

Aerospace technic and technology ◽

10.32620/aktt.2019.7.11 ◽

2019 ◽

pp. 81-86

Author(s):

Дмитро Вікторович Коновалов

Keyword(s):

Fuel Consumption ◽

Exhaust Gas Recirculation ◽

Back Pressure ◽

Specific Fuel Consumption ◽

Design Solution ◽

Exhaust Gas ◽

Engine Fuel ◽

Gas Dynamics Equations ◽

Exhaust Gases ◽

Gas Recirculation

There are many ways and methods to reduce exhaust gases emissions on modern ships. One of the most effective ways to reduce NOx and SOx emissions is to use of exhaust gas recirculation (EGR technology). The EGR system disadvantage is an increase in back pressure through additional pressure losses in the scrubber and heat ex-changer, which entails an engine fuel efficiency deterioration. Creating a reliable and efficient heat exchanger for cooling recirculation gases is a complex task due to deposits and pollution emitted by these gases. In the pre-sent work, the jet apparatus effectiveness named aerothermopressor is analyzed in the scheme with exhaust gases recirculation of the ship low-speed two-stroke engine. Aerothermopressor is a two-phase jet for contact disperse cooling, in which by increasing the heat from the gas stream the gas pressure and cooling are increased. The calculation of the characteristics of the engine was carried out, both in nominal, and in operating modes and in all possible range of partial loads. The installation of the aerothermopressor before the scrubber is pro-posed, which allows reducing engine thermal load. Increasing the pressure in the aerothermopressor by 0.2-0.4 ∙ 105 Pa (6-12 %) allows reducing the back pressure in the gas exhaust system and thus reducing the load on the exhaust gas recirculation fan and when the engine load is higher than 75% in the cold zone, the fan is not need-ed, which additionally allows to reduce the specific fuel consumption. The parameters of the exhaust gases that are going to be recirculated and the processes of their gas-dynamic cooling in the aerothermopressor are based on the developed technique and program using the thermodynamic and gas dynamics equations. The proposed scheme-design solution allows at a high environmental friendliness of the existing exhaust gas recirculation sys-tem to provide a certain reduction in specific fuel consumption. It was determined that the engine specific fuel consumption has been decreasing when the aerothermopressor is used to Dge = 2.5-3.0 g/(kW·h) (1.5-1.7%).

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A Comprehensive Physics-Based Model for Medium-Duty Diesel Engine With Exhaust Gas Recirculation

Volume 16: Transportation Systems ◽

10.1115/imece2007-42119 ◽

2007 ◽

Author(s):

Alok A. Joshi ◽

Scott James ◽

Peter Meckl ◽

Galen King ◽

Kristofer Jennings

Keyword(s):

Heat Transfer ◽

Exhaust Gas Recirculation ◽

Boost Pressure ◽

Exhaust Gas ◽

Variable Geometry ◽

Transfer Effects ◽

Variable Geometry Turbine ◽

Heat Transfer Effects ◽

Egr Cooler ◽

Gas Recirculation

Physics-based models of diesel engines with exhaust gas recirculation and a variable geometry turbine (EGR/VGT) have been developed extensively in the control system design community. However, these models omit the heat transfer effects of the charge-air cooler and the recirculated exhaust gas cooler in order to avoid the added complexity in model order for online implementation. Generally, there is no need to include these effects if the purpose of the model is to control the target variables, such as boost pressure and air-to-fuel ratio. In this paper, after surveying the existing state of physics-based models for the EGR/VGT subsystem, a comprehensive model of the EGR/VGT subsystem is developed. This model includes heat transfer effects in the coolers, pressure drops across air filters and pipes, and mass flow rate calculations for a variable geometry turbine and an exhaust gas recirculation control valve. The purpose and scope of this work is offline modeling-for-diagnostics. Such models, though complex, will assist in the fault sensitivity analysis of a subsystem while avoiding any destructive testing when a major design modification in the EGR/VGT subsystem is proposed. For example, the impact of charge-water or EGR cooler degradation on the boost pressure and the air-to-fuel ratio can be studied with such models to further help in designing diagnostic reasoning strategies. Simulation performed using the proposed physicsbased model demonstrates a dominant failure effect of an EGR cooler coolant leak over a charge-water cooler water leak on the properties of the intake air.

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Combined Effects of a Biobutanol/Ethanol–Gasoline (E10) Blend and Exhaust Gas Recirculation on Performance and Pollutant Emissions

ACS Omega ◽

10.1021/acsomega.9b03303 ◽

2020 ◽

Vol 5 (7) ◽

pp. 3250-3257 ◽

Cited By ~ 1

Author(s):

Lifeng Zhao ◽

Defu Wang

Keyword(s):

Exhaust Gas Recirculation ◽

Pollutant Emissions ◽

Exhaust Gas ◽

Combined Effects ◽

Gas Recirculation

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Experimental study on the effect of high-pressure and low-pressure exhaust gas recirculation on gasoline engine and turbocharger

Advances in Mechanical Engineering ◽

10.1177/1687814018809607 ◽

2018 ◽

Vol 10 (11) ◽

pp. 168781401880960 ◽

Cited By ~ 3

Author(s):

Xianqing Shen ◽

Kai Shen ◽

Zhendong Zhang

Keyword(s):

High Pressure ◽

Fuel Consumption ◽

Gasoline Engine ◽

Exhaust Gas Recirculation ◽

Low Pressure ◽

Operating Conditions ◽

Exhaust Gas ◽

Partial Load ◽

Recirculation System ◽

Gas Recirculation

The effects of high-pressure and low-pressure exhaust gas recirculation on engine and turbocharger performance were investigated in a turbocharged gasoline direct injection engine. Some performances, such as engine combustion, fuel consumption, intake and exhaust, and turbocharger operating conditions, were compared at wide open throttle and partial load with the high-pressure and low-pressure exhaust gas recirculation systems. The reasons for these changes are analyzed. The results showed EGR system of gasoline engine could optimize the cylinder combustion, reduce pumping mean effective pressure and lower fuel consumption. Low-pressure exhaust gas recirculation system has higher thermal efficiency than high-pressure exhaust gas recirculation, especially on partial load condition. The main reasons are as follows: more exhaust energy is used by the turbocharger with low-pressure exhaust gas recirculation system, and the lower exhaust gas temperature of engine would optimize the combustion in cylinder.

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Diesel air path control using pressure difference: Pumping loss and aging considerations

Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering ◽

10.1177/0954407018784696 ◽

2018 ◽

Vol 233 (10) ◽

pp. 2421-2431

Author(s):

Rasoul Salehi ◽

Anna Stefanopoulou ◽

Bruce Vernham

Keyword(s):

Internal Control ◽

Pressure Difference ◽

Exhaust Gas Recirculation ◽

Particulate Filter ◽

Output Coupling ◽

Boost Pressure ◽

Exhaust Gas ◽

Linear Quadratic ◽

Output Controller ◽

Gas Recirculation

Pressure difference across the exhaust and intake manifolds ([Formula: see text] P) is a crucial variable to control the pumping loss and cylinder charge dilution through the exhaust gas recirculation in a diesel engine. This paper presents a novel architecture for controlling [Formula: see text] P and the engine-out NO x emissions, which increases the controller tolerance to engine components aging. The architecture has an internal control loop, designed as a two-input two-output controller, to coordinate the exhaust gas recirculation and variable geometry turbine valves. Using feedback from [Formula: see text] P and the estimated cylinder oxygen ratio [Formula: see text] cyl, the two-input two-output controller regulates the pumping loss and the engine NO x emissions. To reduce high turbo lag and its associated slow air–fuel ratio ([Formula: see text]) response, which are inherent features of a [Formula: see text] P-based control strategy, the two-input two-output linear quadratic controller is tuned such that [Formula: see text] is also regulated, but only during fast transients. An external loop is supplementing the core two-input two-output controller correcting the internal loop set points to reduce the effects of [Formula: see text] cyl estimation errors on NO x control and ensure [Formula: see text] stays above a minimum value, [Formula: see text] min, critical for smoke emissions. As a feature of the proposed control system, direct feedback from [Formula: see text] P increases pumping loss robustness to common degradation in diesel engines, namely, turbine efficiency and diesel particulate filter blockage due to ash deposit, compared to a conventional boost pressure–based controller. Also, it is shown that the input–output coupling structure of the proposed two-input two-output controller and use of the NO x feedback mitigate effects of exhaust gas recirculation fouling and associated exhaust gas recirculation valve saturation on increase in NO x emission.

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