基于热管技术的柴油机燃油加热系统性能分析

Performance Analysis of a Diesel Fuel Heating System Based on Heat Pipe Technology

为了充分利用发动机尾气余热能量,并解决冬季柴油机难以起动的问题,设计了一套冬季柴油机燃油加热快速起动系统。在利用副油箱低标号燃油起动后,将柴油机尾气余热热量通过不锈钢-钠钾合金热管由排气管引至燃油,以实现对油箱中高标号燃油加热。通过台架试验,讨论了某6缸柴油机的余热特性及柴油机可利用尾气余热回收潜力,并在此基础上对热管工作特性进行了试验分析。研究结果表明:在柴油机全工况范围内,排气温度范围为440K^800K,柴油机尾气中至少有1/3的余热能可以利用;热管起动时间仅需275s,可以提供的加热温度范围为350K^600K。试验获取了在限定转速下的有效燃油消耗率与燃油温度变化情况,证明了冬季柴油机燃油加热快速起动系统对发动机的经济性有明显的提升。

In order to take full advantage of an engines exhaust waste heat and to solve the difficult problem of starting a diesel engine during the winter,a set of diesel fuel heating and quick start system was designed.After using the low-grade diesel fuel in the secondary fuel tank to start the engine.The exhaust gas was directed into the main fuel tank from the exhaust pipe through a stainless steel heat pipe to heat the high-grade diesel fuel.The exhaust waste heat characteristics of a six-cylinder diesel engine and its recovery potential were analyzed respectively through the engine bench test.On this basis the working performances of the heat pipe and its system were also tested and analyzed.Results show that at least 1/3 of the diesel engine exhaust waste heat can be where the engine is running in the whole operating range and the exhaust gas temperature range is between 440 Kand 800 K.This systems start-up time is only 275 seconds and available heating temperature is within the range of 350 Kto 600 K.Finally,the relationship between BSFC brake specific fuel consumption(BSFC)and fuel temperature at the specified engine speed was obtained through the experiment.Results prove that the diesel fuel heating and quick start system used in winter has a significant effect on the fuel economy of the engine.