scholarly journals Influence of Sulfur and Additives on Wear of Exhaust Valve Seat of Cylinder Head

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Jianping Zhao ◽  
Shunli Zhang ◽  
Zhenhuan Dou ◽  
YuBo Sun ◽  
Jiangkun Wan ◽  
...  
Keyword(s):  
Sulfur Content ◽  
Contact Surface ◽  
High Power ◽  
Diesel Engines ◽  
Carbon Deposition ◽  
Diesel Oil ◽  
Exhaust Valve ◽  
Composition Analysis ◽  
Valve Seat ◽  
Protection Mechanism

In this paper, taking a certain type of high-power diesel engine exhaust valve abnormal wear phenomenon as an example, we conduct research on the exhaust valve surface micromorphology characteristics, contact surface accumulation products, additive transition layer, and combustion test. These passed diesel sulfur content comparative test, diesel additive composition analysis, and high-sulfur-content and low-sulfur-content diesel and diesel oil additive action test. At present, there is no authoritative research on the influence of sulfur content in diesel on valve seat wear of high-power diesel engines, and the protection mechanism of diesel additives on the valve seat is not clear. The sulfur in diesel, like the lead in gasoline, has long been known to resist wear in the valve seats of high-power diesel engines; just as gasoline additives compensate for the loss of lead, diesel oil additives seem to compensate for the loss of sulfur. Tests show that a uniform carbon deposition layer is formed on the contact surface after the diesel is burned, and the carbon deposition layer is more densely and uniformly adsorbed on the contact surface under the action of diesel additives to form an antiwear layer. Tests also show that the sulfur in diesel has no effect on the wear resistance of the valve seat.

The Research on Thermal-Mechanical Coupled Analysis and the Lightweight Design of Engine Exhaust Valve

2015 ◽  
Vol 729 ◽  
pp. 143-148
Author(s):  
Zhi Yong Deng ◽  
Feng Chong Lan ◽  
Wei Huang ◽  
Hui Guo ◽  
Pei Huan Chen
Keyword(s):  
Stress Distribution ◽  
Wall Thickness ◽  
Contact Surface ◽  
Lightweight Design ◽  
Exhaust Valve ◽  
Coupled Analysis ◽  
Valve Seat ◽  
Engine Exhaust ◽  
Valve Disc ◽  
Exhaust Valves

Four types of exhaust valve models are established, the lightweight on engine exhaust valve is designed. The results on thermal mechanical coupled analysis of four exhaust valve models show that: The maximum values of mises stress appear in contact surface between the valve cone and valve seat; Comparing the maximum mises stress, as wall thickness of the hollow valve increases, there are gradual decrease trends in the same positions of the valve cone, the locking groove, neck and end face of the valve disc. The research on the stress distribution of exhaust valves and the variation law between hollow valves′s strength and their wall thickness provide a good reference for improvement in the future.

УСОВЕРШЕНСТВОВАННАЯ ТЕХНОЛОГИЯ РЕМОНТА ЭЛЕКТРОГИДРАВЛИЧЕСКИХ ФОРСУНОК АВТОТРАКТОРНЫХ ДИЗЕЛЕЙ

2020 ◽  
Vol 4 (141) ◽  
pp. 74-82
Author(s):  
SERGEY TIMOKHIN ◽  
◽  
PAVEL BOGATYREV ◽  
DMITRIY GALIN ◽  
Keyword(s):  
Contact Surface ◽  
Diesel Engines ◽  
Low Cost ◽  
Ball Valve ◽  
Point Of View ◽  
Research Purpose ◽  
Process Time ◽  
Valve Seat ◽  
Economic Point ◽  
Ring Shape

The actual service life of electrohydraulic injectors of automotive diesel engines with a high-pressure battery system of the Common Rail type in operation is significantly lower than the claimed one, and its restoration by repair is relevant from a technical and economic point of view. One of the most wearable elements of electrohydraulic injectors is the contact surface of the ball valve seat. (Research purpose) The research purpose is in developing an improved technology for repairing electro-hydraulic injectors of automotive diesel engines with a vibration-rivet of the contact surface of the ball valve seat. (Materials and methods) The article presents the carried out theoretical substantiation of the process of vibration riveting of the ball valve seat of electrohydraulic injectors and its laboratory and bench studies using serial stands for testing electrohydraulic injectors, checking their elements and restoring the seat geometry by lapping, an electronic digital microscope. (Results and discussion) Authors confirmed the working hypothesis about the possibility of forming the ring contact surface of the ball valve of electrohydraulic injectors reinforced with a vibration riveting by creating certain hydraulic and electrical modes of its operation during the required time. For the model 0445110376 electrohydraulic injectors of the Cummins ISF 2.8 diesel engine, the total area of the hardened surface of the regular ring shape was 0.07 square millimeters, and the depth was about 0.003 millimeters with a process time of 45 minutes. The parameters of the experimental electrohydraulic injectors met the requirements of the test plan, and they are currently successfully undergoing operational tests. (Conclusions) The use of a valve seat vibration rivet will increase the life of repaired injectors at a low cost for its implementation.

scholarly journals THEORETICAL AND EXPERIMENTAL SUBSTANTIATION OF A METHOD FOR INCREASING THE EFFICIENCY OF REPAIR OF ELECTRIC HYDRAULIC NOZZLES OF AUTOMOTIVE DIESEL ENGINES

2021 ◽  
pp. 93-99
Author(s):  
С.В. Тимохин ◽  
П.В. Богатырев ◽  
А.В. Поликанов ◽  
В.А. Мачнев
Keyword(s):  
Contact Surface ◽  
Diesel Engines ◽  
Point Of View ◽  
Valve Seat ◽  
Economic Point ◽  
Alternative Technologies ◽  
Theoretical Substantiation ◽  
Low Costs ◽  
Experimental Substantiation ◽  
Tractor Diesel

В работе рассмотрены вопросы ремонта электрогидравлических форсунок (ЭГФ), широко распространенных в автотракторных и комбайновых дизелях. Фактический ресурс ЭГФ в эксплуатации значительно ниже заявляемого и его восстановление путем проведения ремонтно – обслуживающих воздействий является целесообразным, как с технической, так и с экономической точек зрения. Проведенный анализ характерных неисправностей ЭГФ показывает, что одним из наиболее изнашиваемых элементов ЭГФ является контактная поверхность седла шарикового электромагнитного клапана. Рассмотрены типовые и альтернативные технологи ремонта седла клапана и предложен способ их улучшения вибронаклепом контактной поверхности. Сформулированы цель и задачи исследований. Проведены теоретическое обоснование процесса вибронаклепа седла шарикового клапана ЭГФ и его лабораторные и стендовые исследования, результаты которых подтвердили рабочую гипотезу о возможности формирования упрочненной вибронаклепом контактной поверхности клапана. Применение предлагаемого способа позволит увеличить ресурс отремонтированных форсунок, при небольших затратах на его реализацию. The article deals with the issues of repair of electro-hydraulic nozzles (EHN), which are widespread in automotive and tractor diesel engines. The actual resource of the EHN is significantly lower than the declared one and its restoration by carrying out repair and maintenance operations is expedient, both from a technical and economic point of view. The analysis of typical EHN malfunctions shows that one of the most wear-out elements of EHN is the contact surface of the seat of a ball electromagnetic valve. Typical and alternative technologies for repairing a valve seat are considered and a method for improving them with a vibration hardening of the contact surface is proposed. The goal and objectives of research are formulated. The theoretical substantiation of the process of vibration hardening of the EHN ball valve seat and its laboratory and bench studies, the results of which confirmed the working hypothesis about the possibility of forming a vibration rivet hardened contact surface of the valve, were carried out. The application of the proposed method will increase the resource of the repaired injectors at low costs for its implementation.

Exhaust Valve Seat Leakage

1997 ◽  
Author(s):  
John Hoard ◽  
Peter Moilanen
Keyword(s):  
Exhaust Valve ◽  
Valve Seat

Evaluation of the thermal properties of diesel oil with low sulfur content

2017 ◽  
Vol 131 (1) ◽  
pp. 697-704 ◽  
Author(s):  
Camila G. D. Peixoto ◽  
Valter J. Fernandes ◽  
Ana C. F. Coriolano ◽  
Renkel R. Araujo ◽  
Glauber J. T. Fernandes ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Sulfur Content ◽  
Diesel Oil ◽  
Low Sulfur Content ◽  
Low Sulfur

Diesel Engine Performance Improvement for Constant Speed Application Using CFD

2017 ◽  
Author(s):  
Balasaheb S. Dahifale ◽  
Anand S. Patil
Keyword(s):  
Combustion Chamber ◽  
Fuel Consumption ◽  
Performance Improvement ◽  
Test Data ◽  
Engine Performance ◽  
Exhaust Valve ◽  
Fine Tuning ◽  
Intake Valve ◽  
Valve Seat ◽  
Load Conditions

The detailed investigation of flow behavior inside the combustion chamber and performance of engine is most challenging problem due to constraints in Experimental Data collection during testing; However, Experimental testing is essential for establishment of correlation with CFD Predictions. Hence, the baseline engine was tested at different load conditions and validated with CFD results, before it was optimized for performance improvement. The objective of the CFD Prediction was not only to optimize performance (Fuel Efficiency, Power, Torque, etc.) & Emissions Reduction, but also to assess feasibility of Performance Upgrade Potential. In the present CFD study, surface mesh and domain was prepared for the flame face, intake valve, intake valve seat, exhaust valve, exhaust valve seat and liner for closed volume cycle, between IVC and EVO using CFD code VECTIS. Finally simulations for three different load conditions were conducted using VECTIS solver. Initially, in-cylinder pressure vis a vis crank angle prediction was carried out for 100%, 75% and 50% load conditions. Then the fine tuning of (P-ϴ) diagram for different load conditions was conducted by varying different combustion parameters. Further, the engine performance validation was carried out for rated and part load conditions in terms of, IMEP, BMEP, break specific fuel consumption and power output, while NOx mass fractions were used to convert the NOx to g/kWh for comparison of emission levels with the test data. Finally optimized re-entrant combustion chamber and modified valve timing with optimum fuel injection system simulation was carried out to achieve target performance with reduced fuel consumption. A 3D CFD result showed reduction in BSFC and was in close agreement with the test data.

Research on Application of Waste Plastic Disposal of Marine Diesel Engines

2008 ◽  
Vol 45 (04) ◽  
pp. 191-193
Author(s):  
Wei Hai-jun ◽  
Wang Guo-you ◽  
Wang Xiao-rui
Keyword(s):  
Diesel Engines ◽  
Calorific Value ◽  
Diesel Oil ◽  
Fuel Oil ◽  
Advanced Technique ◽  
Engine Operation ◽  
Waste Plastic ◽  
Marine Diesel ◽  
Points Of View ◽  
Research On Application

The purpose of this paper is to study the applicability of thermal processed fuel oil (hereafter called waste plastic disposal, or WPD) of diesel engines using low-quality fuel oil. In the experiment, stability of engine operation and components of exhaust gas, such as NOx and COx, were inspected from basic and applicable points of view. This paper illustrates a new test and result of WPD oil applied to marine diesel engines. In recent years, efforts have to be made to develop an advanced technique for recycling waste plastics in order to use scrapped plastics as fuel for diesel engines. It is very important and necessary for us to cope with the increasing calorific value and to satisfy the growing need of environment protection. The experimental fuel oil is obtained by a mixing of diesel oil, WPD, and water.

Parametric Study of the Scavenging Process in Marine Two-Stroke Diesel Engines

2015 ◽  
Author(s):  
Fredrik Herland Andersen ◽  
Stefan Mayer
Keyword(s):  
Diesel Engines ◽  
Vortex Breakdown ◽  
Initial Conditions ◽  
Combustion Process ◽  
Operating Conditions ◽  
Exhaust Valve ◽  
Delivery Ratio ◽  
Exhaust Gas ◽  
Scale Production ◽  
Cfd Model

Large commercial ships such as container vessels and bulk carriers are propelled by low-speed, uniflow scavenged two-stroke diesel engines. The integral in-cylinder process in this type of engine is the scavenging process, where the burned gas from the combustion process is evacuated through the exhaust valve and replaced with fresh air for the subsequent compression stroke. The scavenging air enters the cylinder via inlet ports which are uncovered by the piston at bottom dead center (BDC). The exhaust gas is then displaced by the fresh air. The scavenging ports are angled to introduce a swirling component to the flow. The in-cylinder swirl is beneficial for air-fuel mixture, cooling of the cylinder liner and minimizing dead zones where pockets of exhaust gas are trapped. However, a known characteristic of swirling flows is an adverse pressure gradient in the center of the flow, which might lead to a local deficit in axial velocity and the formation of central recirculation zones, known as vortex breakdown. This paper will present a CFD analysis of the scavenging process in a MAN B&W two-stroke diesel engine. The study include a parameter sweep where the operating conditions such as air amount, port timing and scavenging pressure are varied. The CFD model comprise the full geometry from scavenge receiver to exhaust receiver. Asymmetric inlet and outlet conditions is included as well as the dynamics of a moving piston and valve. Time resolved boundary conditions corresponding to measurements from an operating, full scale production, engine as well as realistic initial conditions are used in the simulations. The CFD model provides a detailed description of the in-cylinder flow from exhaust valve opening (EVO) to exhaust valve closing (EVC). The study reveals a close coupling between the volume flow (delivery ratio) and the in-cylinder bulk purity of air which appears to be independent of operating conditions, rpm, scavenge air pressure, BMEP etc. The bulk purity of air in the cylinder shows good agreement with a simple theoretical perfect displacement model.

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