内燃机排气余热ORC中异丁烷-CO2混合工质的可燃性分析

Flammability research of isobutane-CO2 mixture used in Organic Rankine Cycle for engine waste heat recovery

中文关键词: 内燃机，余热，混合工质，可燃极限

英文关键词: internal combustion engine, exhaust heat, mixture, flammability limit

中文摘要:

      针对内燃机高温排气与ORC工质的匹配问题，提出了一组安全且环保的烷烃/CO2混合工质。为了解决混合工质泄漏后可燃的问题，按照美国ASTME681-2009标准测量了异丁烷-二氧化碳混合工质的可燃区域。试验结果表明异丁烷的可燃下限随阻燃剂二氧化碳的加入基本不变，可燃上限随着阻燃剂的加入迅速减小。并基于热力学理建立了预测异丁烷-二氧化碳混合工质可燃极限的模型，与试验值相比较表明，预测模型可以较好地预测异丁烷的可燃下限，上限预测误差稍微较大。

英文摘要:

      To solve the matching problem between high temperature exhaust and working medium in Organic Rankine Cycle (ORC), a novel working medium consisting of alkane and CO2 has been put forward in this paper. This paper proposed a new experimental setup to evaluate the flammable limits of hydrocarbon diluted with CO2 based on ASTME681-2009 criterion. The experimental results show that lower flammability limit increases quite gently with increasing molar fraction of CO2 while upper flammability limit decreases rapidly with increasing molar fraction of CO2 which differs from the case of LFL. This paper has established flammability limit prediction models against isobutane/CO2 mixture on the basis of threshold flame temperature theory. The predicted results of lower flammability limit have good agreement with experimental data while the error of upper flammability limit between estimation and observed data is lager comparing with that of lower flammability limit.