Poise relation to temp w/ various oils

[cgoodwin]

Chart showing the relationship of viscosity to temp with various oils.



Sources of data:
1. Nwafor, O.M.I. "The Effect of Elevated Fuel Inlet Temperatures on Performance of Diesel Engine Running on Neat Vegetable Oil at Constant Speed Conditions." Renewable Energy. 28 (2003) 171-181, p 178.
2. Santos, J.C.O. et.al. "Effect of Heating and Cooling on Rheological Parameters of Edible Vegetable Oil." Journal of Food Engineering. 67 (2005) 401-405, p 403.

[cgoodwin]

Another graph from a seperate data source.

Sources of data:
1. Srivastava, Anjana and Ram Prasad. "Triglyerides-based diesel fuels." Renewable & Sustainable Energy Reviews. 4 (2000) 111-133, p 118.

2. del Almeida, Silvio, et.al. "Performance of a Diesel Generator Fuelled with Palm Oil." Fuel. 81 (2002) 2097-2102, p 2098.
3. Pugazhvadivu, M. and K. Jeyachandran. "Investigations on the Performance and Exhaust Emissions of a Diesel Engine using Preheated Waste Frying Oil as Fuel." Renewable Energy. 30 (2005) 2189-2202, p 2193.
4. Altin, Recep, et.al. "The Potential of Using Vegetable Oil Fuels as Fuel for Diesel Engines." Energy Conversion and Management. 42 (2001) 529-538, p 532.
5. Labesckas, Gvidonas and Stasys Slavinskas. "Performance of Direct-Injection Off-Road Diesel Engine on Rapeseed Oil." Renewable Energy. 31 (2006) 849-863, p 852.
6. Acaroglu, Mustafa, et.al. "An Investigation of the Use of Rapeseed Oil in Agricultural Tractors as Engine Oil." Energy Sources. 23 (2001) 823-830, p 826.
7. Erhan, Sevim and Svajus Asadaukas. "Lubricant Basestocks From Vegetable Oils." Industrial Crops and Products. 11 (2000) 277-282, p 281.

[cgoodwin]

From these two graphs it becomes clear that while different oils have divergent viscosities at lower temperatures, the viscosities of tha various oils converge at between 70 - 80C (158F - 176F). The do not reach the same viscosity as diesel fuel until about 130C (266F) but other studies (a) indicate that the performance and emissions gains from this increase in temp and decrease in viscosity show little gain after 75C. It is possible that this is evidence of further heating taking place in the injectors themselves.


(a)The research paper:

Investigations on the performance and exhaust emissions of a diesel engine using preheated waste frying oil as fuel

M. Pugazhvadivua,(a), K. Jeyachandran(b)

a)Department of Mechanical Engineering, Pondicherry Engineering College, Pondicherry 605014, India
b)Department of Mechanical Engineering, Anna University, Chennai 600025, India

The study relates to the effects of temp on viscosity of waste fryer oil and the temp required to achieve proper viscosity, the effects of heat /viscosity on performance and emissions. The temps tested were 75C and 135C, the first can be attained with coolant exchangers the second was attained in this study with "Electrical coils were wound around the high-pressure fuel injection pipe."

Now if you look at the following graphs it is clear that there is an improvement in both power and emissions when the oil is heated to 75C and a slight improvement in both when temp is increased to 135C, however the improvement is very slight, almost to be negligible in my opinion.