Field-Testing of Biodiesel (B100) and Diesel-Fueled Vehicles: Part 4—Piston Rating, and Fuel Injection Equipment Issues

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Avinash Kumar Agarwal ◽  
Deepak Agarwal

Abstract This study investigated the use of biodiesel (B100) and baseline diesel in two identical unmodified vehicles to realistically assess different aspects of biodiesel's compatibility with modern common rail direct injection (CRDI) fuel injection equipment (FIE) and evaluate biodiesel's long-term durability/compatibility with engine components. Two identical vehicles were fueled with biodiesel (B100) and baseline mineral diesel for 30,000 km field-trials on highway under identical operating conditions. Exhaustive experimental results from this series of tests are divided into four segments. The fourth and the last paper of this series compares the effects of long-term usage of biodiesel on piston deposits and FIE components compared to baseline mineral diesel. A key challenge for improving engine performance and fuel economy is the reduction of frictional losses, primarily at the piston ring–liner interface, which accounts for majority of frictional losses. Piston rating was done for the two vehicles after the conclusion of field-trials and it revealed that rating of different piston sections was ∼5–15% superior in case of biodiesel-fueled vehicle compared to that of diesel-fueled vehicle. Performance of FIE components such as fuel filter, fuel injectors, and fuel pump was assessed after the conclusion of field-trials. Pressure drop at different fuel flow-rates across the fuel filter was measured for assessing the fuel filter blockage. Pressure drop across biodiesel filter was ∼30% higher than diesel filter after 10,000 km usage but almost twice after 15,000 km usage. These experimental results indicated that some additional technical measures should be taken by automotive manufacturers to offset these technical challenges before biodiesel is adapted on a large-scale in modern CRDI vehicles.

1986 ◽  
Vol 108 (2) ◽  
pp. 391-395
Author(s):  
W. J. Dodds ◽  
E. E. Ekstedt

A series of tests was conducted to provide data for the design of premixing-prevaporizing fuel-air mixture preparation systems for aircraft gas turbine engine combustors. Fifteen configurations of four different fuel-air mixture preparation system design concepts were evaluated to determine fuel-air mixture uniformity at the system exit over a range of conditions representative of cruise operation for a modern commercial turbofan engine. Operating conditions, including pressure, temperature, fuel-air ratio, and velocity had no clear effect on mixture uniformity in systems which used low-pressure fuel injectors. However, performance of systems using pressure atomizing fuel nozzles and large-scale mixing devices was shown to be sensitive to operating conditions. Variations in system design variables were also evaluated and correlated. Mixture uniformity improved with increased system length, pressure drop, and number of fuel injection points per unit area. A premixing system compatible with the combustor envelope of a typical combustion system and capable of providing mixture nonuniformity (standard deviation/mean) below 15% over a typical range of cruise operating conditions was demonstrated.


Author(s):  
Sungjun Yoon ◽  
Hongsuk Kim ◽  
Daesik Kim ◽  
Sungwook Park

Stringent emission regulations (e.g., Euro-6) force automotive manufacturers to equip DPF (diesel particulate filter) on diesel cars. Generally, post injection is used as a method to regenerate DPF. However, it is known that post injection deteriorates specific fuel consumption and causes oil dilution for some operating conditions. Thus, an injection strategy for regeneration becomes one of key technologies for diesel powertrain equipped with a DPF. This paper presents correlations between fuel injection strategy and exhaust gas temperature for DPF regeneration. Experimental apparatus consists of a single cylinder diesel engine, a DC dynamometer, an emission test bench, and an engine control system. In the present study, post injection timing covers from 40 deg aTDC to 110 deg aTDC and double post injection was considered. In addition, effects of injection pressures were investigated. The engine load was varied from low-load to mid-load and fuel amount of post injection was increased up to 10mg/stk. Oil dilution during fuel injection and combustion processes were estimated by diesel loss measured by comparing two global equivalences ratios; one is measured from Lambda sensor installed at exhaust port, the other one is estimated from intake air mass and injected fuel mass. In the present study, the differences in global equivalence ratios were mainly caused from oil dilution during post injection. The experimental results of the present study suggest an optimal engine operating conditions including fuel injection strategy to get appropriate exhaust gas temperature for DPF regeneration. Experimental results of exhaust gas temperature distributions for various engine operating conditions were summarized. In addition, it was revealed that amounts of oil dilution were reduced by splitting post injection (i.e., double post injection). Effects of injection pressure on exhaust gas temperature were dependent on combustion phasing and injection strategies.


Author(s):  
Marek Dzida ◽  
Krzysztof Kosowski

In bibliography we can find many methods of determining pressure drop in the combustion chambers of gas turbines, but there is only very few data of experimental results. This article presents the experimental investigations of pressure drop in the combustion chamber over a wide range of part-load performances (from minimal power up to take-off power). Our research was carried out on an aircraft gas turbine of small output. The experimental results have proved that relative pressure drop changes with respect to fuel flow over the whole range of operating conditions. The results were then compared with theoretical methods.


Author(s):  
Haiqi Qin ◽  
Daogang Lu ◽  
Shengfei Wang

Practice has proved that nuclear power technology development and operation of nuclear power is a clean, safe and large-scale provided stable power. AP1000 uses a large number of passive safety technologies. Passive residual heat removal system is an important part, in the long-term cooling stage of nuclear reactor normal operating conditions or accident conditions, to prevent the core meltdown. The research of this paper is to solve the long-term discharge of residual heat of the containment in the accident condition of nuclear power plant. Based on the passive heat removal system of AP1000, combined with the heat transfer characteristics and advantages of heat pipes, the PRHR system is further improved on the basis of the present situation, and a conceptual design of passive containment residual heat removal system is proposed. In order to further verify the feasibility of the conceptual design, we make a simplified simulation of small containment test bench to carry out experimental verification and give a detailed experimental design.


1998 ◽  
Vol 1998 ◽  
pp. 209-209
Author(s):  
N.R. Kendall ◽  
A.M. Mackenzie ◽  
D.V. Illingworth ◽  
D.W. Jackson ◽  
P.M. Driver ◽  
...  

Many sheep in the United Kingdom are grazed on pastures deficient in cobalt and selenium. Proprietary products for selenium and cobalt supplementation often contain copper, which in certain breeds can induce copper toxicity. A soluble glass bolus has been manufactured to supply long term sustained release of cobalt and selenium similar to the commercially available Cosecure, but with the copper content being replaced by zinc. Sub clinical zinc deficiency has been suggested to be involved in disease conditions such as broken mouth periodontitis, footrot and mastitis. Therefore a long term continuous supply of zinc may be beneficial in these situations. This trial was designed to examine the effect of administering a zinc, cobalt and selenium soluble glass bolus on trace element status of over-wintered ewe lambs.


2013 ◽  
Vol 709 ◽  
pp. 309-312
Author(s):  
Xiao Lin Zhu ◽  
Guo Wei Wang ◽  
Qiang Geng ◽  
Chun Yi Li ◽  
Chao He Yang

In this study, pressure drop across a novel CFB riser integrated with an enlarged bottom section was investigated under various operating conditions. Experimental results indicated that total pressure drop was much higher across the riser with larger diameter-enlarged section dimensions, consequently, resulting in lower solids circulation rate realizable in the riser. Based on the measured pressure drop across this novel riser, apparent solids concentrations of the diameter-enlarged section and the conveying section were obtained. Furthermore, empirical correlations for estimating overall average solids concentration in these two sections were established, respectively. And a satisfactory agreement between predictions and experimental results was observed.


Author(s):  
Kesavan Gopalan ◽  
Christopher R Smith ◽  
Simon G Pickering ◽  
Christopher J Chuck ◽  
Christopher D Bannister

Recently, there has been automotive-industry-wide impetus to reduce the overall diesel vehicle emissions and the fuel consumption by increasing the fuel injection pressure within common-rail systems. Many production fuel injection systems are now capable of delivering rail pressures of 1800–2000 bar, with those able to achieve 3000 bar under development. In addition, there has been a gradual increase in the permitted fatty acid methyl ester content in EN 590 diesel from 5% to 7% with further increases to 10% proposed. With these changes, there has been mounting speculation that increasing the injection pressure, particularly with an elevated biodiesel content, can contribute to fuel degradation, deposit formation, fuel filter blocking and corresponding vehicle reliability issues. In this investigation, a bespoke high-pressure fuel injection rig was designed and commissioned to mimic conditions representative of those experienced within a modern vehicle engine. The impacts of the rail pressure, the biodiesel content and the accelerated testing conditions on the stability of the diesel fuel and deposit formation leading to filter blocking were assessed. Despite the abundance of literature on laboratory-based biodiesel degradation, in these more realistic operating conditions it was found that biodiesel did not increase the likelihood of deposit formation within the high-pressure fuel system, with the same level of filter blocking observed for both the baseline diesel B0 (i.e. no biodiesel) and the B10 blend (which contains 10% biodiesel). This implies that the filter-blocking problem caused by onboard fuel degradation has the potential to occur broadly in a wide range of different fuel compositions. B10 fuel tested with a rail pressure of 2000 bar resulted in a pressure drop across the fuel filter of 0.5 bar within 12,000 min (approximately 8.3 days), whereas the corresponding experiment at a rail pressure of 1000 bar showed no increase in the filter pressure. When using model (B10) fuel, filter blocking was observed at rail pressures of both 2000 bar and 1000 bar, but with a lower pressure at a much reduced rate, leading to the belief that the increases in the rail pressure towards 2000 bar has a significant effect on the propensity of vehicle diesel filters to block. Measures taken to increase the severity of the test, such as recirculating injected fuel to simulate shear effects, were found to increase the rate of degradation but did not change the chemical composition of the solids formed, thus implying that they were valid methods of reducing the test duration without introducing new degradation mechanisms. The rig presented here is therefore a suitable accelerated testing system for assessing the behaviour of fuels at higher pressures that will be common throughout the global diesel fleet in the near future.


Author(s):  
Liang-Ming Pan ◽  
De-Qi Chen ◽  
De-Wen Yuan

Narrow channel heat transfer element has been extensive adopted in engineering applications, especially at electronics technology, this kind of elements often be used to construct compact heat exchanger. Pressure drop of flow boiling at vertical channel with gaps of 1.7, 2.2 and 3.6 mm was experimentally investigated in this paper. The variation of the two-phase frictional multiplier vs. heat flux at various operating conditions was gotten experimentally, possible mechanism of the two-phase frictional multiplier trends of narrow channel were analyzed. Experimental results revealed that the two-phase frictional multiplier increased at lower flow rate and heat flux, as well as higher vapor quality, and dropped at wider flow gap. The multiplier can not be estimated by commonly used method for ordinary gap, thus a modified model of pressure drop for narrow channel was proposed considering the size effects of channel. The error of the predicted two-phase frictional multiplier is within ±15.4% compared with experimental results.


1998 ◽  
Vol 1998 ◽  
pp. 209-209
Author(s):  
N.R. Kendall ◽  
A.M. Mackenzie ◽  
D.V. Illingworth ◽  
D.W. Jackson ◽  
P.M. Driver ◽  
...  

Many sheep in the United Kingdom are grazed on pastures deficient in cobalt and selenium. Proprietary products for selenium and cobalt supplementation often contain copper, which in certain breeds can induce copper toxicity. A soluble glass bolus has been manufactured to supply long term sustained release of cobalt and selenium similar to the commercially available Cosecure, but with the copper content being replaced by zinc. Sub clinical zinc deficiency has been suggested to be involved in disease conditions such as broken mouth periodontitis, footrot and mastitis. Therefore a long term continuous supply of zinc may be beneficial in these situations. This trial was designed to examine the effect of administering a zinc, cobalt and selenium soluble glass bolus on trace element status of over-wintered ewe lambs.


Author(s):  
Zbigniew Stepien ◽  
Aleksander Mazanek ◽  
Andrzej Suchecki

This work assessed the potential impact of diesel fuel complying with the EN 590 standard on real diesel injector performance in a long-term field test. Injector deposit formation has been attributed to diesel fuel instability during storage in relation to fuel injection equipment (FIE) operating conditions. These deposits can occur at different locations within FIE and impact on fuel spray characteristics, causing threats to the proper functioning of the fuel injectors. The long-term field tests were performed with two new vehicles fitted with an advanced common rail (CR) fuel injection system, meeting the requirements of Euro 5. A high quality diesel fuel meeting the requirements of the EN 590 standard was used for both vehicles. A scanning electron microscope with energy dispersive X-ray spectrometry (EDS) and an electron backscatter diffraction (EBSD) detector was used for observation and imaging of external, coking injector deposits around the nozzle fuel-flow holes and internal diesel injector deposits (IDID) in the area of the nozzle needle. An elemental analysis was performed by energy dispersive X-ray spectroscopy analysis (EDX). Evaluation of the macroscopic characteristics revealed that, despite the formation of external and internal injector deposits, there was no measurable loss of flow through the injectors. As a result, while injector deposits have adverse impacts on some injector macroscopic characteristics, they did not cause a significant deterioration of the injectors’ operating characteristic and their real performance.


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