重整气爆轰增压燃烧特性分析

Analysis on detonation pressurized combustion characteristic of reformed gas

为了提高燃气轮机的热效率,提出将化学回热技术(CR)与连续旋转爆轰增压燃烧(CRDPC)技术进行有效结合的思路.通过实验研究与数值研究的方法分别考察了不同的甲烷蒸汽重整方案对热回收的影响、重整气的增压燃烧流场特性及燃烧室性能等.结果表明:并列协同催化甲烷蒸汽重整方案具有最佳的重整性能,甲烷转化率和总焓增加率分别达到46.51%和25.28%;重整气组分的差异对爆轰波系流场结构影响较小,但是氢气质量分数的增加可以提高爆轰波传播速度,也会加剧新鲜预混气与上一轮爆轰产物的接触间断处的提前燃烧;在总压相同且重整气与空气以化学当量比进行预混的前提下,重整气中氢气质量分数增加1.1%左右时,预混气入口比质量流量降低约4.5%,但连续旋转爆轰燃烧室增压比降低约6.0%,这主要是接触间断处的提前燃烧造成的.

In order to improve the thermal efficiency of gas turbine, an idea of effective combination of chemically recuperation （CR） with continuously rotating detonation pressur ized combustion （CRDPC） was put forward. The effects of different forms of methane steam reforming on the heat recovery, the characteristics of pressurized combustion flow field and combustion performance of reformed gas were separately investigated through experimental and numerical researches. Results show that synergistic catalytic reforming has the best per formance, with methane conversion rate of 46.51% and total enthalpy increase rate of 25. 28% ; the difference of reformed gas components has little effect on the detonation wave flow structure, but the increase of H2 mass fraction can improve the detonation wave propagation speed, and will intensify the precombustion in the contact discontinuity between fresh mixed gas and detonation products from the previous wave; under the premise of the same total pressure and stoichiometric ratio, when H2 mass fraction increases by about 1.1%, the inlet mass flow rate of premixed gasdecreases by about 4.5%, but the pressurized ratio of CRDPC decreases by about 6.0%, mainly due to the precombustion at the contact discontinuity.