【作者】 马涛；

【导师】 李金平；

【作者基本信息】 兰州理工大学 ， 热能工程， 2010， 硕士

【摘要】 作为清洁、对环境友好的绿色能源,可再生能源的规模开发利用已经成为21世纪解决化石能源造成的能源短缺、环境污染和温室效应等问题的重要途径。其中,太阳能集热技术和沼气技术的推广和应用备受瞩目。然而,由于太阳辐射能量密度小、太阳辐射随季节、昼夜、气候影响大、太阳能很难储存等因素的制约,太阳热能的规模利用受到了巨大限制。同时,传统沼气技术也受到季节、昼夜、气候等因素的严重制约,传统沼气池产气率低、产气量少、冬季不产气的现象普遍存在。为了克服传统太阳能集热技术和沼气技术的不足,本文将这两种技术结合起来,优势互补,提出了一种沼气化学能高效快速储存太阳能的新方法,并将装置在兰州地区进行了实验研究,对其热力性能、经济效益和环保效益进行了分析,获得了如下结果：1.有效容积4m3的装置在冬季日产沼气2.4 m3,容积产气率达0.6m3/(m3.d)。,发酵周期约为30天。在温度较高季节,产气量还会大幅增加,可实现全年的稳定高效供能；2.装置的集热、换热及温控部分协同状况良好,实现了恒温发酵。3.装置在冬季储存太阳热能效率达到了0.65,实现了低品位、不稳定的太阳热能(能量品位0.074)和较高品位生物质能(能量品位0.419)向高品位、稳定的沼气化学能(能量品位0.830)的转化,实现了太阳热能的稳定储存；4.对装置进行了动态性经济分析,项目的财务净现值NPV(i=10%)为6794.35元,内部收益率IRR为26.46%,益本比为1.50,动态投资回收期为5.2年。5.装置具有良好的生态效益以及社会效益。每年可以可保护森林面积0.44公顷,以替代燃煤量为标准年可减排二氧化碳1.30t,二氧化硫0.026t；比之传统农村户用沼气池,年可减排CO21.03t,减排SO20.021t；还可以起到提高农民生活质量、节省劳力、推动科普、优化产业结构等各方面的作用。本课题的创新点是：提出了一种利用沼气化学能储存太阳热能的新方法,并从理论上初步定量揭示了转化储存过程中的能量转化效率和能量品位提升机理。上述研究成果具有重要的学术价值和良好的社会经济效益。它提出了一种低温太阳热能储存的新模式,即太阳能集热--沼气化学能储存,实现了低品位、不稳定太阳热能和较低品味生物质能向稳定、高品位、高能量密度沼气能的高效转化,从理论和技术两方面突破了昼夜、季节、气候等因素对传统太阳能集热或生物质厌氧发酵的束缚,拓展了传统太阳能集热技术与生物制厌氧发酵技术的应用领域,实现了太阳热能和生物质能高效低成本规模开发。在国家政策的大力扶持下,这些研究成果可广泛用于沼气发电、城市固体废弃物资源利用、污水处理、规模畜禽养殖场粪污厌氧处理以及酿酒制糖业等工业有机废水厌氧处理等领域。另外,这些研究成果对利用农村能源解决农村能源需求,推动社会主义新农村建设,调整我国能源结构,发展可再生能源和替代燃料技术两方面均有积极作用,并且能够大幅度节能,降低环境排放,具有良好的社会效益。更多还原

【Abstract】 As a clean, environmentally friendly green energy, the large-scale development and utilization of renewable energy has become an important way to solve the 21st century to solve the energy shortage, environmental pollution, the greenhouse effect and other issues caused by fossil fuels. Among them, The promotion and application of the solar collection and biogas technology attract much attention. However, the large-scale use of solar thermal energy is still subject to some limitations:the solar radiation energy density Earth receiving is low, the intermittent solar radiation and its fluctuation with day and night, seasons and climate, it’s difficult to store solar energy. Meanwhile, the traditional biogas technology also subject to day and night, seasons, climates and other factors. The phenomenon of low gas production rate, less gas production and no gas production in winter of the conventional digesters is widespread.To compensate for the lack of the solar collection and biogas technology, we combine these two techniques with each other’s advantages. A new method of fast and efficient solar heat storage with biogas was put forward. An experimental study on the device was carried out in Lanzhou. Analysised its thermal performance, economic and environmental benefits, we obtained the following results:1. The device of effective volume 4 m3 can produce biogas 2.4 m3 per day in winter. Its volume gas production rate archived 0.6m3/(m3·d). The fermentation time was about 30 days. The gas production rate will increase substantial in the warm season. The device can supply energy stably and efficiently throughout the year;2. The collaboration of heating, heat transfer and temperature control part is good. The device can archive constant temperature fermentation;3. In winter, the solar heat storage efficiency was up to 0.65. It transformed the low-grade (energy grade,0.074) unstable solar energy and biomass energy (energy grade,0.419) to the high-grade stable biogas chemical energy (energy grade, 0.830)and achieved significantly improve on the energy grade;4. Using the method of dynamic economic to appraise the entire system. The project’s financial net present value NPV (i=10%) was￥6794.35, internal rate of return IRR was 26.46%, the internal returns ratio was 1.50, the dynamic investment recovery period was 5.2 years;5. Device has a good ecological benefit and social benefit. Protection of forest area per year can be 0.44 ha..Coal burning replaced as the standard, the annual emissions of carbon dioxide and sulfur dioxide can be 1.30t and 0.026t per year; Compared with the conventional digester, the annual emissions of carbon dioxide and sulfur dioxide can be 1.03t and 0.021t per year. It also can play an important role in improving living quality of farmers, labor-saving, promoting science, optimizing the industrial structure and other aspects.The innovation of this topic is:A new method of fast and efficient solar heat storage with biogas was put forward. The energy conversion efficiency and upgrade principle of energy grade was initial quantitative theoretical revealed in the process of transforming.The findings have important academic values and good social and economic benefits. It presents a new low-temperature solar thermal energy storage mode, the solar collector-gas chemical energy storage, which achieved the efficient conversation of low-grade unstable solar heat and low-grade biomass energy to the high-grade stable high-energy-density biogas energy. It breaks out the limits of the day and night, seasons, weather and other factors theoretically and technically, expands the applications of traditional solar collector system and anaerobic fermentation technology, achieves high efficiency and low cost development of solar heat and biomass energy. In the strong support from national policy, these finding can be used broadly in biogas power generation, municipal solid waste resource use, wastewater treatment, large-scale anaerobic treatment of livestock manure and organic wastewater anaerobic treatment in wine sugar industry and other industrial areas. Moreover, the results of these studies have positive effects on meeting rural energy needs using rural energy, promoting the building of socialist new countryside, China’s energy structure adjustment, the development of renewable energy and alternative fuel technologies. It can save energy significantly,reduce environmental releases, and have good social benefits.更多还原