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961.
生物柴油及其生产技术的进展 总被引:5,自引:0,他引:5
介绍了由可再生油脂原料衍生的环保燃料生物柴油在国内外应用现状,重点介绍了酯交换法制备生物柴油技术研究进展情况,展望了生物柴油产业在我国的发展前景。 相似文献
962.
在缸内直喷汽油机(GDI)上采用多次燃油喷射和可变配气技术来控制缸内混合气形成和燃烧,实现了SI/HCCI复合燃烧方式。研究了不同压缩比和辛烷值对均质混合气压燃(HCCI)燃烧排放特性的影响。结果表明,汽油HCCI燃烧呈现单阶段燃烧燃料特性,HCCI着火发生在上止点附近时油耗低。低压缩比下,HCCI燃烧可以在较浓空燃比下工作,NOx排放较高。高辛烷值燃料HCCI燃烧可运行的负荷范围窄。汽油HCCI发动机在偏高压缩比条件下燃用偏低辛烷值汽油可以获得较好的经济性和排放性能。 相似文献
963.
964.
965.
电子低压冲击器不同稀释比对PM2.5排放测试的影响 总被引:1,自引:0,他引:1
燃煤电厂PM2.5排放检测技术是目前研究的热点和难点,电子低压冲击器(ELPI)可以实时得到颗粒物的质量浓度,方便工程现场测试。利用ELPI对扬州第二发电厂600 Mw机组湿法脱硫后烟气进行测试研究,并分别尝试采用一级稀释器和两级稀释器两种方法进行比较,结果表明:两种稀释比测得颗粒数浓度粒径分布规律基本一致,采用两级稀释测得PM1、PM2.5、PM2.5数浓度结果均小于一级稀释;对于质量浓度,采用两级稀释测得PM1、PM2.5结果小于一级稀释,而PM2.5测量结果却大于一级稀释。 相似文献
966.
The performance of sewage heat exchangers plays an important role in the sewage source heat pump systems when the sewage does not enter the heat pump unit directly, especially when untreated sewage is used as heat or cold source. In this article, a free-flow channel heat exchanger is proposed to be used in an untreated sewage source heat pump system. First the article designs the sizes of heat exchanger according to the real system requirements, and then it models and analyzes dynamic characteristics on the simulink platform. The transfer functions that are suitable for the heat exchanger are deduced. The analysis shows that the wall temperature is 9.1°C when the untreated sewage and water temperatures at the inlet are 15 and 7°C, respectively. The result is obtained when considering the temperature at the outlet is affected by the temperature at the inlet. The variable quantity of water temperature at the outlet is affected greatly by the variable quantity of water temperature at the inlet and the variable quantity of sewage temperature at the outlet by the variable quantity of sewage temperature at the inlet. Besides, the measured values of water temperatures at the inlet and outlet are also observed from the real system where the free-flow channel heat exchanger is adopted. The variable quantities of water temperature at the outlet are calculated according to the measured values, and are compared with the model results deduced by the transfer functions. The comparative result shows that the differences between the measured and model results of water temperature variable quantities at the outlet range from ?1 to 1°C, thus getting the water temperatures at the outlet according to the model results. The differences of the water temperature at the outlet between the measured values and the deduced results are from ?0.5 to 0.5°C. It illustrates the temperature at the outlet can be estimated by modeling the temperature variable quantity at the outlet. 相似文献
967.
以某台660MW超超临界机组为例,通过燃烧调整及SCR运行调整,研究了主要运行参数对氨逃逸率的影响.结果表明:氨逃逸率随着脱硝效率提高而提高,当脱硝效率高于设计值(65%)时,氨逃逸率上升幅度增大;SCR入口NOx质量浓度存在一个最佳值(约200mg/m3)使得氨逃逸率最低,最佳的燃尽风率和最佳氧体积分数分别为18%和3%,过高的燃尽风率或过高的氧体积分数对氨逃逸率的影响尤其显著;在额定机组负荷下,氨逃逸率较高,而机组负荷在500 MW及以下时,氨逃逸率总体降低约60%. 相似文献
968.
Haisheng Di Xin He Peng Zhang Zhi Wang Margaret S. Wooldridge Chung K. Law Cuiping Wang Shijin Shuai Jianxin Wang 《Combustion and Flame》2014
Experimental and numerical studies have been performed on the thermal and chemical effects of buffer gas composition on low temperature ignition of iso-octane and n-heptane. Experiments were conducted using a recently developed rapid compression machine in the temperature range of 600–850 K. Three buffer gases were studied including nitrogen (N2), argon (Ar), and a mixture of Ar and carbon dioxide (CO2) at a mole ratio of 65.1%/34.9%. Iso-octane was studied at 20 bar, ? = 1, and a dilution level of buffer gas to O2 of 3.76:1 (mole ratio). n-Heptane was studied at 9 bar, ? = 1, and a dilution level of buffer gas to O2 of 5.63:1 (mole ratio). For experiments where two-stage ignition was observed, the buffer gas composition had no impact on the first-stage ignition time but, as expected, it caused differences in the total heat release, pressure and temperature rise after the first-stage ignition. As a consequence, significant differences were observed for the total ignition delay time as a function of the buffer gas composition, with up to 40% and 42.5% faster total ignition time for iso-octane and n-heptane, respectively, by using Ar instead of N2. The chemical effects of the buffer gas composition were studied experimentally by comparing the results of the N2 and Ar/CO2 (65.1%/34.9%) mixtures, recognizing that while the Ar/CO2 mixture has the same heat capacity as N2, its predicted combined third-body collision efficiency is about 76% higher than N2. The experimental results showed negligible chemical effects on the first-stage and total ignition delay times. Numerical simulations were carried out over a wider range of temperatures for pure N2, Ar, and CO2 as buffer gases. Results showed that thermal effects are very pronounced and dominated at the negative temperature coefficient and two-stage ignition conditions, which is consistent with the experimental results and previous studies in the literature. However, the simulation results also showed at temperatures higher than 850 K, the chemical effects of CO2 became more important than the thermal effects. 相似文献
969.
Quan Li Xuxu Sun Xing Wang Zhi Zhang Shouxiang Lu Changjian Wang 《International Journal of Hydrogen Energy》2018,43(46):21572-21581
Geometrical influence of the perforated plate on flame propagation in hydrogen-air mixtures with various equivalence ratios and initial pressures was experimentally investigated in a channel with the length of 1 m and the cross-section of 7 cm × 7 cm. The perforated plate has the same cross section and three thicknesses of 40 mm, 80 mm and 120 mm. High-speed schlieren photography was employed to capture the flame shape evolution and derive the flame tip velocity. High-speed piezoelectric pressure transducers were flush-mounted upstream and downstream of the perforated plate to measure the pressure transient. It was found that, with the perforated plate in the path of flame, flame undergoes either “go”, or “quench” propagation mode. The limit between these two was dependent on the geometrical size of the perforated plate and the initial conditions of mixtures. Both velocity and pressure were effectively attenuated with the increase in the perforated plate length. Moreover, for “go” propagation mode, the flame process through the perforated plate was characterized by three obvious stages: laminar flame stage, jet flame stage and turbulent flame stage. Whereas, only laminar flame stage was observed in the “quench” mode. 相似文献
970.