Investigation of Injector Tip Deposits on Transport Refrigeration Units Running on Biodiesel Fuel

The objective of this paper is to investigate the injector tip deposits on Transport Refrigeration Units (TRU's) running on 100% Biodiesel (B100) fuel. Both laboratory and field testing of TRU equipment with B100 Biodiesel reveal hard, black deposits that interfere with optimum spray pattern on the injectors in about 1000 hours of operation. This paper investigates the composition and source of those deposits. In addition, this paper summarizes the testing of two alternatives to reduce injector tip deposits: 1) A TRU engine run with B100 fuel and a detergent fuel additive 2) A TRU engine run with B20 blend of Biodiesel (20%) and petroleum diesel (80%).