1. Introduction
Lubricating oil is one of the most important liquids that are
used in almost all vehicles and machines. Lubricating oils play a
dual role of heat transfer and that of friction reduction that reduces
the heat generated in internal combustion engines. Basically, the
main ingredient of lubricant oil is the base oil, which is refined
from crude oil or synthesized in the laboratory. Base oil is mixed
with additives to enhance the ability of the oil to act as a layer between
contact surfaces.
Modern lubricating oil is made of base stock or base oil (71.5–
96.2 wt%), blended with a few ppm of chemical additives according
to its grade and specific duty. Additives are added to fulfill the specific
requirement for lubrication. Each lubricant oil consisted at
least one type of additive or nearly 30% by weight of additives (Table
1) [1].
During usage, lubricating oils undergo changes termed degradation
and contamination, which render them ineffective for further
application. Lubricating oil goes through normal degradation and
about 50% of it is consumed in the process. The rest of the oil picks
up a number of contaminants from the working environment, such
as, residual components of engine fuels, solids from wear processes
along with corrosion products and dirt, soot, combustion products
etc. [2]. Degradation involves changes in the desired viscometric
properties of oil as a result of alteration in the lubricating oil
molecular structure caused by cracking, isomerization and polymerization
reactions prompted by high temperatures in the run-
1385-8947/$ - see front matter 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.cej.2012.12.076
1. 1. Introduction
บทนำน้ำมันหล่อลื่นเป็นหนึ่งในของเหลวที่สำคัญที่สุดที่จะนำมาใช้ในยานพาหนะเกือบทุกเครื่อง Lubricating oil is one of the most important liquids that are
น้ำมันหล่อลื่นเล่นสองบทบาทของการถ่ายโอนความร้อนและลดแรงเสียดทานของที่ช่วยลดความร้อนที่เกิดในเครื่องยนต์สันดาปภายใน โดยทั่วไปส่วนผสมหลักของน้ำมันน้ำมันหล่อลื่นเป็นน้ำมันพื้นฐานที่กลั่นจากน้ำมันดิบหรือสังเคราะห์ในห้องปฏิบัติการ น้ำมันพื้นฐานผสมกับสารเติมแต่งเพื่อเพิ่มความสามารถของน้ำมันที่จะทำหน้าที่เป็นชั้นระหว่างพื้นผิวที่สัมผัสน้ำมันหล่อลื่นโมเดิร์นที่ทำจากหุ้นฐานหรือน้ำมันพื้นฐาน - 96.2% ถึงชั้นประถมศึกษาและหน้าที่เฉพาะของตน สารเติมแต่งที่มีการเพิ่มเพื่อตอบสนองความเฉพาะเจาะจงความต้องการสำหรับการหล่อลื่น used in almost all vehicles and machines. Lubricating oils play a
dual role of heat transfer and that of friction reduction that reduces
the heat generated in internal combustion engines. Basically, the
main ingredient of lubricant oil is the base oil, which is refined
from crude oil or synthesized in the laboratory. Base oil is mixed
with additives to enhance the ability of the oil to act as a layer between
contact surfaces.
Modern lubricating oil is made of base stock or base oil (71.5–
96.2 wt%), blended with a few ppm of chemical additives according
to its grade and specific duty. Additives are added to fulfill the specific
requirement for lubrication. Each lubricant oil consisted at
least one type of additive or nearly 30% by weight of additives (Table
1) [1].
During usage, lubricating oils undergo changes termed degradation
and contamination, which render them ineffective for further
application. Lubricating oil goes through normal degradation and
about 50% of it is consumed in the process. The rest of the oil picks
up a number of contaminants from the working environment, such
as, residual components of engine fuels, solids from wear processes
along with corrosion products and dirt, soot, combustion products
etc. [2]. Degradation involves changes in the desired viscometric
properties of oil as a result of alteration in the lubricating oil
molecular structure caused by cracking, isomerization and polymerization
reactions prompted by high temperatures in the run-
1385-8947/$ - see front matter 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.cej.2012.12.076
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