A fundamental study of injection, spray, and combustion characteristics of hydrotreated vegetable oil under simulated diesel engine conditions

การศึกษาคุณลักษณะพื้นฐานของการฉีดสเปรย์และการเผาไหม้ของเชื้อเพลิง Hydrotreated vegetable oil ภายใต้การจำลองการเผาไหม้แบบเครื่องยนต์ดีเซล

Name: Vo Tan Chau

Organization : King Mongkut's Institute of Technology Ladkrabang. Faculty of Engineering

ThaSH: Diesel motor -- Combustion

ThaSH: Petroleum as fuel -- Combustion

ThaSH: Diesel motor -- Fuel systems

Abstract: Fossil fuels have been the essential source of energy in the global development for centuries. However, along with the continual rise in the fossil fuels consumption come the pollution and the environmental degradation. Thus, attempts have been made to mitigate the fossil fuels-related environmental impacts through the renewable and more environmentally-friendly energy alternatives. Hydrotreated Vegetable Oil (HVO) is seen as a modern paraffin based fuel promising to substitute petro-diesel. The influences of physical/chemical properties of HVO to engine performance and emissions formation have been investigated the feasibility through a sequence of experiments before applying popularity on the market. This work concentrated on the analysis of injection, spray, combustion and emission characteristics of HVO which are considered as the most important features on engine. These experiments were carried out in the injection rate-Zeuch measurement system, constant volume combustion chamber (CVCC), and rapid compression expansion machine (RCEM) respectively under direct injection (Dl) diesel engine conditions. The experimental fuels were the commercial diesel fuel (B7), the neat HVO, the 10%, 20%, 30%, 50%, 80% HVO (by mass fraction) blended with diesel fuel (B7). The results indicated that bulk modulus of compressibility, injection delay, average injection rate, injection quantity were inversely correlated to HVO fraction in blend. Adjusting injection duration was required to obtain the injected fuel amount equally into combustion chamber. In addition, the findings revealed the higher discharge coefficient with HVO as well as under higher injection pressure. Regarding to spray evolution, slightly shorter in penetration length during fully developed zone was observed with higher HVO fraction in blend. The larger spray cone angle of HVO and its blends compared to diesel was caused by the difference in viscosity, density, surface tension and the higher differential pressure. The effects of HVO’s fuel properties, variable oxygen concentrations and injection pressures were clearly revealed in results of combustion and emissions. The ignition delay, the heat release rate, the flame temperature, the soot density-KL factor, the NOₓ and soot- out emissions were decreased as increasing the HVO fraction in the blend. In addition, the findings revealed the similar flame profiles in which the higher flame temperature region and the darker KL density were concentrated around the spray flame upstream, regardless of the HVO mixing ratio. Besides, the decrease in the O₂ concentration resulted in the lower heat release rate, integral heat release, flame temperature, KL factor and NOₓ emissions but the longer ignition delay and higher soot concentration, with the highest soot concentration observed under the 15% O₂ environment. Nevertheless, the higher pressure differential (i.e. between the injection pressure and the ambient pressure) contributed to the shorter ignition delay, higher heat release rate, early peak of the flame temperature, wider combustion area, faster soot oxidation rate and higher NOₓ production.

King Mongkut's Institute of Technology Ladkrabang. Central Library

Address: BANGKOK

Email: Lifelong@kmitl.ac.th

Name: Chinda Charoenphonphanich

Role: Thesis Advisor

Email : chinda.ch@kmitl.ac.th

Created: 2017

Modified: 2563-08-31

Issued: 2020-08-31

CallNumber: EThesis

eng

DegreeName: Doctor of Engineering (Mechanical Engineering)

Level: Doctoral Degree

Descipline: Mechanical Engineering

Grantor: King Mongkut's Institute of Technology Ladkrabang

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