共查询到19条相似文献,搜索用时 281 毫秒
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在联产系统能量和物质转换过程模拟和分析的基础上,重点研究了热功转换过程及其与甲醇合成过程的相互影响.得到部分联产率对系统输出功、甲醇合成压缩机耗功、甲醇产量、合成塔副产蒸汽的影响.并对比了动力独立生产系统和部分联产系统供电效率. 相似文献
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《工程热物理学报》2015,(4)
本文基于高温太阳能热化学等温法循环分解H_2O或CO_2制备H_2或CO,通过在其下游加入甲烷进行重整及部分氧化反应,在进行余热余气回收的同时实现了甲醇动力多联产,提出三种系统方案并进行了能耗及效率分析。结果表明,等温法同时分解水和CO_2的甲醇动力多联产系统,可以取消水煤气变换反应及CO_2的分离单元,进行合理的热回收后达到太阳能甲醇转换效率为30.52%,制取甲醇的净太阳能能耗为65.25 GJ/t,甲烷单耗为25.74 GJ/t。采用甲烷互补的甲醇动力多联产可取代超高温换热器以及甲醇合成过程的自备电厂,与仅有太阳能作为输入的高温太阳能热化学双温法制取甲醇相比,效率可提升两倍。 相似文献
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冷热电联产系统节能特性分析 总被引:6,自引:0,他引:6
本文分析各子系统性能和补燃量对冷热电联产系统总体性能的影响,得到了与分产系统相比联产系统节能所需满足的条件,并建议采用以联产系统燃料量为基准的节能系数评价联产系统性能。通过对回收的热量在制冷子系统和供热子系统中的分配情况研究,确定了回收热量优先利用的原则。补燃量的增加将导致联产系统性能下降,到一定程度使联产系统与分产系统相比不具有优势;随着电网供电效率的提高,确保联产系统节能所需的联产系统发电效率也不断提高。 相似文献
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本文针对煤基和天然气基DME分产及多联产系统进行研究.通过分析发现煤基DME分产能耗为55.5 GJ/t,天然气基DME分产能耗为48.4 GJ/t.煤基IGCC-DME联产方式相对节能率达到15.0%,高于天然气基CC-DME联产方式的10.2%.通过进一步的分析发现,不论是煤基还是天然气基,联产方式都同时遵循化学(火用)和物理(火用)的综合梯级利用原理. 相似文献
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本文针对传统焦炭生产工艺的不足、并应用联产系统整合思路,研究提出新型焦炭动力联产系统.新系统取消了传统炼焦工艺中直接燃用焦炉煤气为炭化室提供炼焦热量的方式,采用外置煤炭燃烧室提供热量,从而实现用低品质煤炭替代高品质焦炉煤气;节省下来的富氢、高热值的焦炉煤气作为燃料提供给联合循环,实现高效洁净发电;改进炼焦过程烟气废热回收方式,使得排烟损失大大降低.分析结果表明,新系统具有优良的热力性能,相对节能率高达15%左右.对系统关键过程的图像(火用)分析分析表明,燃烧过程和换热过程等变革与改进是系统性能提升的关键所在.本文研究将为冶金生产的可持续发展提供新思路与新系统方案. 相似文献
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D. Kaczmarek S. Shaqiri B. Atakan T. Kasper 《Proceedings of the Combustion Institute》2021,38(1):233-241
Methane based polygeneration processes in piston engines offer the possibility of a controllable and flexible conversion of energy, to up-convert low value chemicals and to store energy. These processes preferably take place under fuel-rich conditions and at high pressures. Under fuel-rich conditions, there was one experimental report that a distinctive negative temperature coefficient (NTC) behavior occurs in methane oxidation (Petersen et al., 1999). To design a polygeneration process, reliable kinetic models are required to capture the impact of pressure and equivalence ratio variations on reactivity of the gas mixtures. Here, the experimental basis for methane oxidation is expanded to high pressures and very fuel-rich conditions and compared to literature models, both with special emphasis on the NTC behavior. The oxidation of methane/oxygen mixtures at 2 ≤ Φ≤ 20 and pressures ranging from 1 to 20 bar is investigated. The literature reaction mechanisms are assessed with respect to their ability to predict this phenomenon and used to identify reaction pathways. It is found that NTC behavior occurs in a temperature range between 700 and 1000 K and at pressures higher than 5 bar. The lower temperature limit is slightly shifted towards higher temperatures with decreasing equivalence ratio. In addition, the higher the equivalence ratio, the broader the pressure range, in which the NTC behavior is observed. In general, predictions of some models are in good agreement with the experimental data. Reaction path analyses reveal that the competition between oxidation and recombination pathways are responsible for the NTC region in methane oxidation. 相似文献
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Dominik Schröder Kai Banke Sebastian A. Kaiser Burak Atakan 《Proceedings of the Combustion Institute》2021,38(4):5567-5574
Fuel-rich combustion of methane in a homogeneous-charge compression-ignition (HCCI) engine can be used as a polygeneration process producing work, heat, and useful chemicals like syngas. Due to the inertness of methane, additives such as dimethyl ether (DME) are needed to achieve ignition at moderate inlet temperatures and to control combustion phasing. Because significant concentrations of DME are then needed, a considerable part of the fuel energy comes from DME. An alternative ignition promotor known from fuel-lean HCCI is ozone (O3). Here, a combined experimental and modelling study on the ignition of fuel-rich partial oxidation of methane/air mixtures at Φ = 1.9 with ozone and DME as additives in an HCCI engine is conducted. Experimental results show that ozone is a suitable additive for fuel-rich HCCI, with only 75 ppm ozone reducing the fuel-fraction of DME needed from 11.0% to 5.3%. Since ozone does not survive until the end of the compression stroke, the reaction paths are analyzed in a single-zone model. The simulation shows that different ignition precursors or buffer molecules are formed, depending on the additives. If only DME is added, hydrogen peroxide (H2O2) and formaldehyde (CH2O) are the most important intermediates, leading to OH formation and ignition around top dead center (TDC). With ozone addition, methyl hydroperoxide (CH3OOH) becomes very important earlier in the compression stroke under these fuel-rich conditions. It is then later converted to CH2O and H2O2. Thus, ozone is a very effective additive not only for fuel-lean, but also for fuel-rich combustion. However, the mechanism differs between both regimes. Because less of the expensive additives are needed, ozone could help improving the economics of a polygeneration process with fuel-rich operated HCCI engines. 相似文献