Cummins L10 Injector Depositing Test to Evaluate Diesel Fuel Quality

Current developments in fuels and emissions regulations are resulting in an increasingly severe operating environment for diesel fuel injection systems. The formation of deposits within the holes or on the outside of the injector nozzle can affect the overall system performance. The rate of deposit formation is affected by a number of parameters, including operating conditions and fuel composition. For the work reported here an accelerated test procedure was developed to evaluate the relative importance of some of these parameters in a high pressure common rail fuel injection system. The resulting methodology produced measurable deposits in a custom made injector nozzle on a single cylinder engine. The results indicate that fuels containing 30%v/v and 100% Fatty Acid Methyl Ester (FAME), that does not meet EN 14214 produced more deposit than an EN590 petroleum diesel fuel. Overall, the addition of zinc to the fuel had the biggest effect on deposit formation and resulted in a 12.2% decrease in Indicated Mean Effective Pressure (IMEP). The effects of zinc were unexpectedly reduced when it was added to fuel containing 30%v/v biodiesel. Reducing the common-rail pressure with 30%v/v biodiesel (no added zinc) increased the loss in IMEP. Raising the air and fuel temperatures by 40°C and 30°C respectively showed no bigger loss in IMEP. The results indicate that deposit formation may continue after engine shut down.

Section: Visual Comparison Of Nozzle Exteriorsmentioning

confidence: 99%

Investigations on Deposit Formation in the Holes of Diesel Injector Nozzles

Birgel¹,

Ladommatos²,

Aleiferis³

et al. 2011

“…The development and introduction of fuel additives to reduce injector fouling subsequently followed [2]. In 1991, Gallant et al [3] noted that deposits caused spray hole plugging and sticking of close fitting parts leading to power loss and increased emissions. Recent deposit problems have come from the promotion of diesel engine technology advances resulting in improved combustion process from finer fuel atomization.…”

Section: Introductionmentioning

confidence: 99%

The Application of New Approaches to the Analysis of Deposits from the Jet Fuel Thermal Oxidation Tester (JFTOT)

Barker

Reid

Smith

et al. 2017

Studies of diesel system deposits continue to be the subject of interest and publications worldwide. The introduction of high pressure common rail systems resulting in high fuel temperatures in the system with the concomitant use of fuels of varying solubilizing ability (e.g. ULSD and FAME blends) have seen deposits formed at the tip of the injector and on various internal injector components. Though deposit control additives (DCAs) have been successfully deployed to mitigate the deposit formation, work is still required to understand the nature and composition of these deposits. The study of both tip and internal diesel injector deposits (IDID) has seen the development of a number of bench techniques in an attempt to mimic field injector deposits in the laboratory. One of the most used of these is the Jet Fuel Thermal Oxidation Tester or JFTOT (ASTM D3241). The tester was originally designed to assess the oxidation of jet fuel, based on the principle that low stability fuels produce deposits that form on metal surfaces. Recently it has been modified so that under suitable conditions it may be used to determine the deposit forming potential of diesel fuels. The JFTOT technique has been used by a number of groups to try and understand diesel injector deposits. The ineradicable nature of the material on the JFTOT tube has seen the deposits analyzed by laser scanning microscopy, ellipsometry and recently infra-red microscopy. Other methods have been invasive involving either solvent washing or scraping off the deposit. In this paper other techniques for the analysis of deposits will be described yielding both chemical and metrological characteristics of the deposits. Fourier Transform Infrared Microscopy (FTIRM), and Time-of-Flight Secondary Ion Mass Spectrometry (ToFSIMS) will be used to describe the surface characteristics. Measurements from a Profile meter will be used to estimate deposit surface roughness and data from Scanning Electron Microscopy (SEM) will be employed to describe the morphology. The final techniques described will be Direct Analysis In Real Time Mass Spectrometry (DARTMS) using ambient mass spectrometry. and Fourier Transform Ion Cyclotron Resonance Mass spectrometry (FTICRMS) The advantage of the DART method is that mixtures and objects can be subjected to mass spectrometric analysis with the minimum of pre-treatment and sample preparation. Thus the technique is well suited for analyzing deposits on JFTOT tubes as it requires little sample preparation. A number of studies of materials deposited on JFTOT tubes will be described showing the suitability of these techniques for analyzing and providing the potential characterization of JFTOT deposits. The FTICRMS will be used to assign species in the JFTOT test fuels both pre and post test.

“…In the 1980s deposits on the injector pintle were noted [1], enabling the technology of fuel additives to reduce diesel injector fouling [2]. Increased emissions from the plugging of spray holes was found in 1991 [3], and increased emissions legislation forced changes in fuel and engine design [3,4]. Recent changes in fuel properties such as solubilsing ability [5] caused for example by the introduction of ULSD and the introduction of more stringent emission regulations along with the increased tolerances, temperatures and pressures in modern diesel injector systems has seen the formation of internal injector deposits (IDID).…”

Section: Introductionmentioning

confidence: 99%

Spectroscopic Studies of Internal Injector Deposits (IDID) Resulting from the Use of Non-Commercial Low Molecular Weight Polyisobutylenesuccinimide (PIBSI)

Barker¹,

Reid²,

Snape³

et al. 2014

Since 2009, there has been a rise in deposits of various types found in diesel fuel injection systems. They have been identified in the filter, the injector tip and recently inside the injector. The latter internal diesel injector deposits (IDIDs) have been the subject of a number of recent publications, and are the subject of investigations by CRC (Central Research Council Diesel Performance Group-Deposit Panel Bench/ Rig Investigation sub panel) in the US and CEN (Committee European de Normalisation TC19/WG24 Injector Deposit Task Force) and CEC (Coordinating European Council TDFG-110 engine test) in Europe. In the literature one of the internal injector deposit types, amide lacquers, has been associated with a poorly characterised noncommercial low molecular weight polyisobutylene succinimide detergent which also lacked provenance. This work will describe a well characterised non-commercial low molecular weight polyisobutylenesuccinimide, the engine tests associated with it and the spectroscopic analysis of the needle of the resultant stuck injectors. An engine test of a commercial grade PIBSI detergent that showed no sticking will also be described.