Reliability of DPF-Systems: Experience with 6000 Applications of the Swiss Retrofit Fleet

摘要: The Swiss 1998 Ordinance on Air Pollution Control (OAPC) mandates curtailment of carcinogenic Diesel particle emissions at construction sites [4]. In addition traps are compulsory underground workplaces [3]. compliance, more than 6,000 engines were retrofitted with different trap systems. Many surpassed 99% filtration efficiency, from the beginning, and secondary mostly prevented. However, failure due to mechanical thermal damage was initially rather high about 10%. By Y-2000 rate halved 6%. Thanks focussed improvements, Y2003 statistics show yearly failures “only” 2%. target is retrofit 15,000 machines traps, fully compliant environmental directives, having 5,000 operating hours durability rates below 1% . Fig1: Contribution on-road off-road in Switzerland. Note relatively impact site [19], despite much fewer trucks agriculture tractors. Construction have higher PM-emission factors trucks, operated intensely Traps must pass VERT suitability test before deployment. type certification for a representative example family comprises very detailed measurements characteristics tendency emissions. system also verified typical field deployment during 2,000 hours. Moreover, all periodically inspected functionality. Trap cancelled when 5% detected annually. This paper reports quality VERT-Test both new state after prolonged least examines failures, their causes prevention based information manufacturers, retrofitters independent inspections. work performed close collaboration regulatory authorities trade association AKPF manufacturers retrofitters. experience this large fleet shows applicability various design, power range age – directive includes no exceptions. technology demonstrated as technically, operationally economically feasible. However there several important prerequisites: comprehensive testing, careful function monitoring regular inspection. Thus targeted effectiveness dependability ensured.