Effects of ambient oxygen concentration on soot temperature and concentration for biodiesel and diesel spray combustion

Handle URI:
http://hdl.handle.net/10754/564181
Title:
Effects of ambient oxygen concentration on soot temperature and concentration for biodiesel and diesel spray combustion
Authors:
Zhang, Ji; Jing, Wei; Roberts, William L. ( 0000-0003-1999-2831 ) ; Fang, Tiegang
Abstract:
Ambient oxygen concentration, a key variable directly related to exhaust gas recirculation (EGR) levels in diesel engines, plays a significant role in particulate matter (PM) and nitrogen oxides (NOx) emissions. The utilization of biodiesel in diesel engines has been investigated over the last decades for its renewable characteristics and lower emissions compared to diesel. In an earlier work, we demonstrated that the soot temperature and concentration of biodiesel were lower than diesel under regular diesel engine conditions without EGR. Soot concentration was quantified by a parameter called KL factor. As a continuous effort, this paper presents an experimental investigation of the ambient oxygen concentration on soot temperature and KL factor during biodiesel and diesel spray combustion. The experiment was implemented in a constant volume chamber system, where the ambient oxygen concentration varied from 21 to 10% and the ambient temperature was kept to 1,000 K. A high speed two-color pyrometry technique was used to measure transient soot temperature and the KL factor of the spray flame. The soot temperature of biodiesel is found to be lower than that of diesel under the same conditions, which follows the same trend from our previous results found when the ambient temperature changes to 21% oxygen conditions. A reduction in ambient oxygen concentration generally reduces the soot temperature for both fuels. However, this is a complicated effect on soot processes as the change of oxygen concentration greatly affects the balance between soot formation and oxidation. The KL factor is observed to be the highest at 12% O2 for diesel and 18% O2 for biodiesel, respectively. On the other hand, the 10% O2 condition shows the lowest KL factor for both fuels. These results can provide quantitative experimental evidences to optimize the ambient oxygen concentration for diesel engines using different fuels for better emissions characteristics. © 2014 American Society of Civil Engineers.
KAUST Department:
Clean Combustion Research Center; Mechanical Engineering Program; Physical Sciences and Engineering (PSE) Division
Publisher:
American Society of Civil Engineers (ASCE)
Journal:
Journal of Energy Engineering
Issue Date:
Jun-2015
DOI:
10.1061/(ASCE)EY.1943-7897.0000214
Type:
Article
ISSN:
07339402
Sponsors:
This research was supported in part by the Faculty Research and Professional Development (FRPD) Fund from the North Carolina State University and by the Natural Science Foundation under Grant No. CBET-0854174. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the funding agencies.
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Mechanical Engineering Program; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorZhang, Jien
dc.contributor.authorJing, Weien
dc.contributor.authorRoberts, William L.en
dc.contributor.authorFang, Tiegangen
dc.date.accessioned2015-08-03T12:35:24Zen
dc.date.available2015-08-03T12:35:24Zen
dc.date.issued2015-06en
dc.identifier.issn07339402en
dc.identifier.doi10.1061/(ASCE)EY.1943-7897.0000214en
dc.identifier.urihttp://hdl.handle.net/10754/564181en
dc.description.abstractAmbient oxygen concentration, a key variable directly related to exhaust gas recirculation (EGR) levels in diesel engines, plays a significant role in particulate matter (PM) and nitrogen oxides (NOx) emissions. The utilization of biodiesel in diesel engines has been investigated over the last decades for its renewable characteristics and lower emissions compared to diesel. In an earlier work, we demonstrated that the soot temperature and concentration of biodiesel were lower than diesel under regular diesel engine conditions without EGR. Soot concentration was quantified by a parameter called KL factor. As a continuous effort, this paper presents an experimental investigation of the ambient oxygen concentration on soot temperature and KL factor during biodiesel and diesel spray combustion. The experiment was implemented in a constant volume chamber system, where the ambient oxygen concentration varied from 21 to 10% and the ambient temperature was kept to 1,000 K. A high speed two-color pyrometry technique was used to measure transient soot temperature and the KL factor of the spray flame. The soot temperature of biodiesel is found to be lower than that of diesel under the same conditions, which follows the same trend from our previous results found when the ambient temperature changes to 21% oxygen conditions. A reduction in ambient oxygen concentration generally reduces the soot temperature for both fuels. However, this is a complicated effect on soot processes as the change of oxygen concentration greatly affects the balance between soot formation and oxidation. The KL factor is observed to be the highest at 12% O2 for diesel and 18% O2 for biodiesel, respectively. On the other hand, the 10% O2 condition shows the lowest KL factor for both fuels. These results can provide quantitative experimental evidences to optimize the ambient oxygen concentration for diesel engines using different fuels for better emissions characteristics. © 2014 American Society of Civil Engineers.en
dc.description.sponsorshipThis research was supported in part by the Faculty Research and Professional Development (FRPD) Fund from the North Carolina State University and by the Natural Science Foundation under Grant No. CBET-0854174. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the funding agencies.en
dc.publisherAmerican Society of Civil Engineers (ASCE)en
dc.subjectAmbient oxygen concentrationen
dc.subjectBiodieselen
dc.subjectConstant volume chamberen
dc.subjectDieselen
dc.subjectExhaust gas recirculation (EGR)en
dc.subjectSpray combustionen
dc.subjectTwo-color pyrometryen
dc.titleEffects of ambient oxygen concentration on soot temperature and concentration for biodiesel and diesel spray combustionen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.contributor.departmentMechanical Engineering Programen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalJournal of Energy Engineeringen
dc.contributor.institutionDept. of Mechanical and Aerospace Engineering, North Carolina State Univ., 911 Oval Dr.-Campus Box 7910, Raleigh, NC, United Statesen
kaust.authorRoberts, William L.en
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