Impacts of Biodiesel Blends on Fuel Filters of High Pressure Common Rail (HPCR) System

2016 ◽  
Author(s):  
Ta-Wei Tang ◽  
Yong-Yuan Ku ◽  
Chun Lin Chen
2014 ◽  
Vol 852 ◽  
pp. 808-814
Author(s):  
Di Ming Lou ◽  
Chen Chen Zhang ◽  
Zhi Yuan Hu ◽  
Pi Qiang Tan ◽  
Jian Jun Lin

An experimental study was conducted in a high-pressure common-rail diesel engine fueled with biodiesel-diesel blends (the volume ratio of biodiesel is 20%). Influences of post-injection parameters on gaseous and particulate emissions are studied. The results show that post injection timing has greater influence on particulate emissions of biodiesel engine in comparison with post injection quantity. With the delay of post injection timing, NOX emissions firstly reduce and then increase and again slightly reduce, while particulate emissions initially increase and then decrease and again soar, indicating a trade-off relationship. With the increase of post injection quantity, NOX emissions hardly change except at the low engine load, while particulate emissions increase in general. In order to improve the emission performance comprehensively, the injection parameters have to be recalibrated and split injection strategy has to be reformulated when the diesel engine is fueled with biodiesel blends.


Author(s):  
Zhenbo Gao ◽  
Yong Zhang ◽  
Dandan Wang

Plunger pair is the key component of high pressure common rail injector and its sealing performance is very important. Therefore, it is of great significance to study the leakage mechanism of plunger pair. Under static condition, the high-pressure fuel flow in the gap of the plunger pair caused the deformation of the plunger pair structure and the temperature rise of fuel. For a more comprehensive and accurate study, the effect of deformation, including elastic deformation and thermal expansion, the physical properties of fuel, including density, viscosity and specific heat capacity, as well as the influence of plunger posture in the plunger sleeve, including concentric, eccentric, and inclination condition, are considered in this paper. Firstly, the mathematical models including Reynolds equation, film thickness equation, non-isothermal flow equation, parametric equation of fuel physical property, and section velocity equation are established. The numerical analysis based on finite difference method for the solution of these models is given, which can simultaneously solve for the fuel film pressure distribution, temperature distribution, thickness distribution, distribution of fuel physical properties, and leakage rate. The models are validated by comparing the calculated leakage rates with the measurements. The effects under different posture of plunger are discussed too. Some of the conclusions provided good guidance for the design of high-pressure common rail injector.


2011 ◽  
Vol 347-353 ◽  
pp. 66-69
Author(s):  
Jian Xin Liu ◽  
Song Liu ◽  
Hui Yong Du ◽  
Zhan Cheng Wang ◽  
Bin Xu

The fuel spray images were taken with an equipment (camera-flash-injection) which has been synchronized with a purpose made electronic system under the condition of the high pressure common rail in two injection pressure has been expressed in this paper. It is discovered when fitting spray tip penetration that after jet breakup for a period of time, the spray tip begin to slow down rapidly, and the speed of spray tip running becomes smooth. Hiroyasu and other traditional tip penetration fitting formula are fitting larger to this phase. This is because that after jet breakup, the secondary breakup of striker particles will occur under the influence of the aerodynamic, surface tension and viscosity force. Therefore, a spray penetration fitting formula containing secondary breakup time to fit penetration in three sections was proposed in this paper. Results show that when pressure difference increase, both first and second breakup time become earlier. The former is because of gas-liquid relative velocity increasing, while the latter is due to high speed interface movement acceleration increasing.


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