北方“四位一体”农村能源生态模式的能流分析及其系统评价

以沈阳农业大学中国北方综合能源示范基地内的"四位一体"北方农村能源生态模式为研究对象,根据实际试验数据,运用能流分析的方法,对该系统的3个子系统的能量投人和产出进行了计算、比较和分析.结果表明:该系统的运行情况良好,农业生产结构相对合理,能量相对密集,是一个生产力水平一般、综合效益可观的现代化农业生态系统.在综合分析和评价过程中,发现系统还存在一些不足之处,针对这些不足提出了改进建议.     

光伏阵列变阵调整输出算法的研究

针对多子系统的光伏发电大系统,提出了光伏阵列变阵思想,并给出了光伏变阵调整输出算法及控制器的设计。当光照强度较好时,各子系统独立的正常工作。随着光照强度降低,变阵控制器根据系统所需求的负载要求,改变大系统的结构,对各子系统进行系统重组。重组后系统将部分子系统的能量资源补充给其他子系统,使部分子系统的能量满足负载的要求,进而延长了发电系统的工作时间。通过一个仿真例子说明了给出方法的有效性及可行性。     

JL465Q5发动机点火线圈特性研究

针对JL465Q5发动机,以ATmega8单片机为核心,成功开发出一套应用天然气的电控点火系统,该系统已在发动机台架试验中成功应用。为了优化发动机的燃烧过程,对点火能量进行了测试。试验采用改变点火线圈的初级回路的闭合时间,测试点火线圈的初级断开电流、次级输出电压和电流,计算出点火线圈的初级储能、次级输出能量以及点火线圈的能量转化效率。试验结果表明,点火线圈的初级储能在闭合时间为6ms时接近饱和,继续增大闭合时间,初级线圈储能和次级输出能量都不再继续增大;随着闭合时间的增长,点火线圈的能量转化效率不断下降。     

The effect of an energy storage unit on the performance micro CCHP systems

分布式冷热电联供系统作为传统分布式供能系统的延伸,在继承传统系统能量分级利用优点的同时,其供能效率和经济性都有很大的提升。为保证系统冷、热、电负荷按照既定的规律变化,维持能量的输出与负荷需求相匹配,确保较高的运行效率,创新地加入储能子系统。本文通过定性分析的方法,针对储能子系统在分布式冷热电联供系统中的作用展开讨论,结合微型冷热电联供系统的模拟结果,对储能子系统进行初步的设计和计算,证明储能子系统的加入对分布式冷热电联供系统的效率和稳定性均有提升。     

储能子系统对微型冷热电联供系统的影响

分布式冷热电联供系统作为传统分布式供能系统的延伸,在继承传统系统能量分级利用优点的同时,其供能效率和经济性都有很大的提升。为保证系统冷、热、电负荷按照既定的规律变化,维持能量的输出与负荷需求相匹配,确保较高的运行效率,创新地加入储能子系统。本文通过定性分析的方法,针对储能子系统在分布式冷热电联供系统中的作用展开讨论,结合微型冷热电联供系统的模拟结果,对储能子系统进行初步的设计和计算,证明储能子系统的加入对分布式冷热电联供系统的效率和稳定性均有提升。     

JIA65Q5发动机点火线圈特性研究

针对JIA65Q5发动机,以ATmega8单片机为核心,成功开发出一套应用天然气的电控点火系统,该系统已在发动机台架试验中成功应用.为了优化发动机的燃烧过程,对点火能量进行了测试.试验采用改变点火线圈的初级回路的闭合时间,测试点火线圈的初级断开电流、次级输出电压和电流,计算出点火线圈的初级储能、次级输出能量以及点火线圈的能量转化效率.试验结果表明,点火线圈的初级储能在闭合时间为6ms时接近饱和,继续增大闭合时间,初级线圈储能和次级输出能量都不再继续增大;随着闭合时间的增长,点火线圈的能量转化效率不断下降.     

铁电晶体热电转化回热循环的性能优化准则

考虑铁电晶体热电能量转化回热循环的有限时间性以及热阻和铁电介质的损耗等不可逆因素，定义回热循环能量转化的特征参量λ，对循环性能进行优化研究，给出铁电晶体热电转化最大输出功率状态下的优化准则以及功率与效率协调的优化准则，为回热式电晶体热电能量转化装置的优化设计提供理论依据。』     

线性唯象传热规律下复杂系统的热力学优化

实际传热过程并不总是服从牛顿传热规律,传热规律对循环性能有很大影响.利用非平衡热力学中常用的传热规律--线性唯象传热规律,对复杂系统进行了研究.该复杂系统包括若干不同温度的热源、有限热容子系统和一个变换器(热机或制冷机).利用拉格朗日方程得到了变换器的工质最优温度和子系统的最优自由温度,求出了系统相应的最大功率输出,并与牛顿传热规律下的结果进行了比较,计算方法为计算实际复杂系统的温度分布和能量界限提供了一种途径.     

直接驱动浮子式波浪能转换装置频域模拟研究

基于线性波理论,仅考虑浮体的垂荡运动,并假设能量输出系统是线性的,建立直接驱动的浮子式波浪能转换装置频域运动方程,获取该系统的频率响应函数,推导该系统能量俘获宽度在规则波和随机波浪条件下的表达式,研究浮体形状、频率响应函数、能量输出系统阻尼系数及海洋波浪条件对能量俘获宽度的影响。数值算例结果表明:系统固有频率与波谱谱峰频率越接近,频率响应函数的幅值越大,能量输出系统的阻尼系数越大,则系统的能量俘获宽度越大。     

太阳能喷射式制冷功冷联供系统

以太阳能为驱动热源,基于喷射式制冷和ORC,构建一种太阳能喷射式制冷功冷联供系统,该系统分为太阳能集热子系统和功冷联供子系统两部分。以R161为功冷联供子系统循环工质,通过Matlab建立该系统热力学模型,对其性能进行模拟,在设计工况下该系统制冷量为2.893 kW,净输出功为1.594 kW,功冷联供子系统制冷效率为12.47%,发电效率为6.87%,效率为41.45%。通过分析可知,该系统损占比较大的部件依次为太阳能集热器（73.3%）、发生器（12.14%）、蒸发器（5.03%）和透平（4.81%）。考虑到实际过程,分别研究系统内部参数改变和外部环境参数改变,对系统的影响,发现高低压发生器的温升由利于系统性能的提升,同时环境温度的升高以及太阳辐照度的提升均可改善集热器效率,从而提升系统性能。     

户用沼气池对农村家庭能源消费的影响--以江苏省涟水县为例

户用沼气池建设不但改变了农村家庭能源消费结构，还带动了农村养殖业、种植业的发展。通过对江苏省涟水县农村家庭能源消费和沼气池使用等相关问题的入户调查，定量研究了户用沼气池建设所产生的影响。证明户用沼气池的使用能提高家庭能源利用效率，减少能源消费量和化肥的使用量，有利于农作物秸秆的还田，提高农户的生活质量。     

太阳能辅助加热户用沼气池系统设计

沼气开发利用是发展可再生能源的重要选择,户用沼气是我国农村能源的重要组成部分.文中介绍了沼气的产生原理及发展现状,针对北方寒冷地区冬季气温低,沼气产气少利用率低问题,在调研常规保温增温方法的基础上提出了家用太阳能热水器辅助加热户用沼气池系统,并对系统经济性进行了分析.     

陕西户用沼气池越冬使用技术研究

为了有效解决陕西省农村户用沼气池使用时间短的难题,结合陕西农村的实际情况,对传统沼气池的结构形式进行了改进,增加预处理池为沼气池提供热量,并对沼气池的池墙、进(出)料口进行保温,以达到增加冬季沼气池池温的目的。以榆林市为代表,通过理论计算、试验等手段,证明冬季最低室外温度条件下,沼气池产气率可以达到0.1 m3/(m3.d)以上,一口6～8 m3的沼气池就可以满足一个普通农户一天的炊事用气要求。     

Agricultural waste resources and biogas energy potential in rural areas of Lao PDR

Lao PDR lacks of conventional energy resources, such as oil and natural gas, and 100% of fossil fuels are imported from abroad. Fossil fuel consumption in Lao PDR in 2010 was about 561 million liters and rapidly increased to 716 million liters by 2015. However, Lao PDR has a high potential for renewable energy, especially from hydropower, agricultural wastes, and livestock wastes, in which agricultural and livestock annually produced a large amount of agricultural residues as a favorable renewable energy sources. In 2016, productivity crops were estimated for 24,608,840 ton and these products amount can be generated annual agricultural residues for 12,525,000 ton, which can be estimated to total of energy potential was 197,840 GJ or 55,001 GWh. The majority of livestock in country are buffaloes, cattle, swine, and poultry; large amount of livestock manure produced from each region and can be feedstock as substrate for biogas digester, which these amounts were estimated about 1,583,740 kg TS/day, and equivalent to 439,917 m3/day of biogas production or 658,376 kWh/day of energy generation. Therefore, objective of this paper is unique to promote and research development the agroforestry residues and livestock wastes as renewable energy resources, and its energy potential for biofuel production, including, biodiesel, bioethanol and biogas in each region of Laos.     

“三位一体”沼气池建设整体质量评价指标体系

随着我国沼气事业的发展,全国"三位一体"沼气建设规模不断扩大,评价某一地区的"三位一体"沼气池建设整体质量水平,评估沼气项目建设实施水平和生态效果,制定"三位一体"沼气池整体质量评价指标体系至关重要。文章从"三位一体"沼气建设区域适宜性指标体系、沼气建设质量体系、沼气服务体系等方面,可以评估出某一区域的沼气建设的科学性和整体建设质量水平。     

4m3商品化户用玻璃钢沼气池的实际运行效果

在云南省已试验示范和推广了4m^3商品化户用玻璃钢沼气池1000多口，基本上能够解决5口之家的日常生活用能，使用管理方便，深受农户欢迎。实际运行的统计分析表明，平均年产沼气600m^3以上，原料产气率为0．377m^3/kg，沼气的甲烷含量超过65％。     

Productive use of bioenergy for rural household in ecological fragile area,Panam County,Tibet in China: The case of the residential biogas model

Bioenergy is the major domestic energy for rural households in developing countries due to its cheap or easy-getting characteristics. Productive use of bioenergy is an important strategy for rural households to improve not only their income, but also their health, living environment and so on. In Tibet of China, which is rich in cattle dung and firewood as the major energy sources for rural households, the efficiency of energy utilization is just about 10%. In order to improve energy utilization efficiency and the living conditions for rural residents, the Tibet Autonomous Region government introduced residential biogas model (RBM) to local households, which was a comprehensive utilization system of energy integrated with residential biogas digester, vegetable greenhouse and livestock shed. This paper aims to show the productive use of the bioenergy by the RBM, which could be depicted as the feasibility and the benefits on economic, eco-environmental and social aspects of biogas utilization, based on household questionnaires in Panam County. In RBM, biogas digester works as the biomass material supplement loop to transform originally biomass flow from single-direction to recycling-direction. The results indicate that the output of unit biogas digester could replace 1.44 t of firewood, 1.65 t of agricultural residues and 1.75 t of cattle dung, respectively. The net incremental benefit of RBM could reach 5550.72 Yuan in 15 years. The reduced amount of CO₂ emission when substituted by biogas in other agricultural areas and the areas of semi-agricultural and semi-husbandry in Tibet could be (76.66–79.89) × 10⁴ t/year and the capability for nitrogen storage could achieve (0.39–0.99) × 10⁴ t/year. The amount of cattle dung replaced by biogas could reach 78.29 × 10⁴ t/year; this means that the saved cattle dung, 3.51 t/hm², could be reallocated back to cultivated land to improve the soil fertility and to keep the balance of nutrient elements in cultivated land. Biogas utilization reduces the labor opportunity costs of women compared to use of traditional bioenergy sources. It could be concluded that the productive use of bioenergy through RBM in this area has its capability to release the current pressures on biomass sources by adjusting patterns of rural energy consumption, and to improve the conditions of health, environment, economy and energy conservation.     

Anaerobic fermentation technology increases biomass energy use efficiency in crop residue utilization and biogas production

A biomass energy utilization project (Corn stalk→Cattle→Cattle dung→Biogas digester→Biogas/Digester residues→Soil) was conducted in a typical temperate agro-village of China from 2005 to 2010. The present study focused on two key approaches of the ecological loop: (1) increasing corn stalk use efficiency by improving anaerobic fermentation technology; and (2) enhancing biogas productivity by optimizing fermentation conditions. Our results showed that crude protein and fat of corn stalks significantly increased, while crude fiber content and pH decreased considerably during anaerobic fermentation. The cattle digestion rate, forage consumption and increases in cattle weight were higher in cattle fed fermented corn stalks than in those fed non-fermented corn stalks. The rate of biogas production was higher (78.4%) by using cattle dung as a substrate than using crop residues. Heat preservation measures effectively enhanced the biogas production rate (12.3%). In 2005, only two cattle were fed in this village, with only 1.1% corn stalk utilized as forage. No more than three biogas digesters existed, and the proportion of biogas energy used in total household fuel was only 1.7%. At the end of the 5-year experiment, the number of cattle capita reached 169 with 78.9% corn stalk used as forage. Biogas digesters increased to 130, and the proportion of biogas energy used in total household fuel was up to 42.3%. A significant positive correlation was noted between the increasing rate of farmers’ incomes and the proportion of corn stalks used as forage. Available nutrients were higher in fermented cattle dung than in fresh cattle dung. Our findings clearly suggest that anaerobic fermentation technology is important in enhancing crop residue use efficiency, biogas productivity and soil fertility. Fermentation technology may help reduce the use of fossil fuels and improve the environment in rural areas.     

寒区太阳能和沼气锅炉联合增温系统及试验研究

发展应用沼气可有效利用农作物等废弃资源,降低能源消耗,减少环境污染.但我国北方冬季气温低,致使沼气池产气率极低,甚至发生池体冻裂,无法正常使用.通过建立太阳能沼气锅炉联合增温系统,试验测试并分析了沼气池内温度变化,确定了太阳能与沼气锅炉联合运行的匹配方式.结果表明联合增温系统能使沼气池体处于较好的发酵温度范围内,保证了...     

解决牛粪厌氧发酵中浮渣结壳的几种方法

在畜禽养殖场沼气发电工程中,牛粪具有固体及纤维物质含量高的特点.在厌氧发酵过程中极易在厌氧反应器内部形成浮渣层并硬化结壳,如不及时解决,将导致沼气无法顺利进入气室,严重影响厌氧反应器的正常运行.针对这个问题,文章介绍几种在实际工程中经常用到的防止浮渣结壳的方法(高位出料、机械搅拌、反冲回流等),供工程设计人员参考.