Application of Low-Temperature Phase Change Materials to Enable the Cold Weather Operability of B100 Biodiesel in Diesel Trucks

Abstract

The use of B100 biodiesel for compression ignition engines during the winter poses a challenge due to gelling and plugging of engine filters and fuel lines. The most common method to prevent this issue is blending it with petroleum diesel and many engine manufacturers limit the biodiesel in blends to 20% or less for warrantee purposes; as low as 5% may be set for winter months. In this research, an experimental analysis is performed using a scaled model of the fuel tank with canola oil as a test fluid in the tank. An insulated tank is subjected to an ambient temperature of −20 °C in an icing tunnel facility with air velocity at 10 m/s. The results show that the time for the oil to drop from 20 °C to 5 °C was increased from 18.6 h to 22.5 and 33 h, respectively, when 4 and 12 tubes containing phase change materials (PCM) were inserted in the tank containing 33 l of canola oil. A numerical model was further formulated to predict the transient temperature of the oil and comparison with experimental results showed excellent agreement. Finally, the developed numerical model was used to simulate different designs to investigate the effect of tank filling level, overall heat transfer coefficient, number of PCM modules, and diameter of PCM modules on the tank performance. The results show that B100 can be implemented in diesel engines in cold climates using a passive approach using engine coolant.