Effects of an Exhaust Heat Recovery System on Performance Characteristics of a Forklift Truck

Abstract

Construction equipment has consumed a lot of energy with a high workload compared to commercial vehicles of the same class. So, fuel efficiency is one of the important indicators of merchantability of the construction equipment. Especially, because forklift has been generally used only when necessary, the work has been carried out without adequate warm-up. So, not only the thermal efficiency of the engine of the construction equipment has deteriorated but also the sufficient fluidity of auto transmission fluid and hydraulic fluid have been hardly able to secure. Therefore, the exhaust heat recovery (EHR) system which consists of exhaust heat recovery unit and auto-transmission fluid (ATF) heater has been developed to improve the fuel economy of forklift by recovering the waste heat of exhaust gas. The performance tests of a 4.5 ton forklift have been carried out to evaluate the effects of exhaust heat recovery system on the fuel economy under the VDI fuel consumption drive cycle. It has found that the fuel consumption of a 4.5 ton forklift can be reduced through the fast warm-up of the auto-transmission fluid by recovering the waste heat of exhaust gas.