户用钢制辅热式沼气发酵系统试验研究

HS01型户用钢制辅热式沼气发酵系统是一种新型高效全天候的沼气发酵装置,其中的燃煤沼气联合辅助加热装置解决了我国北方地区冬季户用沼气难以正常发酵的问题,可使其全天候高效生产沼气。通过试验研究了影响HS01型户用钢制辅热式沼气发酵系统运行的主要因素,结果表明当温度30~35℃、总固体浓度10%、投料时间间隔9d时处于最优运行工艺条件,池容产气率高达0.7658 m3·m-3d-1,并且HS01型户用钢制辅热式沼气发酵系统的益本比为2.319,净现值(NPV)为2644.17元,内部收益率(FIRR)为54.69%,动态投资回收期2.062a,具有较好的经济可行性和显著的社会环境效益,符合我国国情,适合于在我国北方地区广大农村应用。     

户用太阳能恒温沼气生产系统批式半连续发酵产气性能试验

在甘肃省民勤县测试户用太阳能恒温沼气生产系统以半连续工艺发酵的产气性能。在当地冬季气象条件下,产气系统半连续补料厌氧发酵试验结果发现:该系统采用半连续补料发酵可在冬季最低环境温度为-18.2℃时连续稳定运行。在116 d试验期内,平均日产沼气0.95 m~3,累计产气110.71 m~3;当达到最低环境温度时,系统可实现在(27±2)℃的范围内的稳定产气;批式厌氧发酵过程半连续补料可维持较稳定的甲烷含量,平均甲烷含量为54.74%;另外,该产气系统在基质浓不变的度条件下可通过调节发酵温度,满足不同时期4～5口人家庭的生活燃气用量的需求。     

太阳能辅助加热户用沼气系统的瞬时计算分析

设计了太阳能辅助加热户用沼气池系统.太阳集热器集热通过螺旋管换热器加热沼液.为了评价系统的加热效果,对系统进行优化设计,建立了系统数学模型,对系统冬季运行情况进行计算分析.结果表明,太阳能辅助加热户用沼气系统能有效提高沼气池内温度.     

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.     

温度对蔬菜垃圾与猪粪混合消化产沼气特性的影响

采用批式厌氧消化实验,在10 L反应系统中将蔬菜垃圾与猪粪以1∶2质量比进行混合发酵,探究温度(20、32、37、52℃)对二者混合消化产气特性的影响。结果表明,中、高温(32、37、52℃)条件下混合发酵系统稳定,室温(20℃)发酵后期有轻微酸抑制。32℃时产沼气性能最佳,总产气量分别是20、37和52℃时的4.65、2.08和1.42倍,发酵过程中p H值、挥发性脂肪酸和氨氮浓度均在正常范围。3 m~3户用沼气池试验表明,蔬菜与猪粪32℃混合发酵的池容产气率为0.56 m~3/(m~3·d),平均甲烷体积分数为54.83%,日平均产气量为1.68 m~3。蔬菜与猪粪32℃混合发酵既可维持发酵系统稳定性,又能改善产沼气性能,为蔬菜废弃物的沼气化处理提供参考。     

户用沼气管理与维护存在的问题及解决措施

介绍了松阳县户用沼气技术在推广过程中发现的管理和维护方面存在的问题，并详细介绍了沼气运行管理和技术服务网络等经验，为各地户用沼气建设的发展提供了借鉴。     

高寒地区户用太阳能沼气发酵系统的设计

以呼和浩特地区冬季环境条件和太阳能辐射数据为依据,设计了一套适用于严寒地区冬季气温条件下的户用太阳能沼气发酵系统。沼气发酵池体积为6 m3,通过计算沼气池的热负荷,得出维持池内正常产气所需的热量为37.7 MJ;采用真空管太阳能集热器循环系统,太阳能集热器的集热面积为5.17 m2,所需真空管数量为50根,储热水箱的容积为0.72 m3。     

炕连灶热烟通道沼气系统的热平衡分析

气温较低是影响寒冷地区低温季节户用沼气池正常运行的主要原因之一。文章设计了一种炕连灶热烟通道沼气池,利用炕连灶烟气余热实现沼气池增温保温,并对该系统进行了热平衡分析。结果表明:炕连灶热烟通道沼气系统可使寒冷地区低温季节沼气池温平均提高17℃,可满足沼气池正常、高效运行的条件要求,为我国农村地区户用沼气池正常运行提供参考。     

吉林省农村户用沼气建设的适宜性评价分析

户用沼气的区域适宜性评价是农村户用沼气建设合理布局的关键。针对吉林省农村户用沼气建设现状,探讨了农村户用沼气建设的影响因素,从气温条件、原料供给、社会经济等几方面建立评价指标体系;以吉林省的40个县为样本县,运用主成分分析法,评价了样本县农村户用沼气建设的适宜性,分析了样本县适宜性的空间分布特征,并采用聚类分析法进行了区域划分。     

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％。     

Power conditioning system for grid-connected photovoltaic system

This study develops a new control strategy for an expandable grid-connected photovoltaic (PV) system. The proposed system performs dual functions of a PV generation and an active power filter, or either one. To this end, the grid current, instead of output current of the converter, is shaped to be a sinusoidal current in phase (or opposite phase) with the grid voltage. Furthermore, its reference current is generated in multiplying the voltage loop controller output by the grid voltage waveform, and therefore non-active components analysis for harmonics elimination and reactive power compensation in the conventional design is not necessary. As a result, the algorithm is simple and easy to implement, and only one sensor for current detection plus two voltage sensors are required. Experimental results verified the effectiveness of the proposed method.     

微型热电联产系统

作为一种以家庭住宅为单位的全新的能源供应思路和技术 ,微型热电联产系统代表了未来家庭能源供应的主要方向。本文分别介绍了基于斯特林发动机、内燃机和燃料电池的三种微型热电联产方式的原理及特点 ,并进行了系统的性能比较     

基于模型的航天器推进系统故障诊断

设计了基于模型的推进系统的故障诊断系统,根据推进系统的结构和行为模型,分析出各组件可处的工作状态及组件之间的连接关系,利用JMPL建模语言建立了推进系统各组件的定性模型。把推进系统模型和系统场景文件输入给诊断推理引擎,可实现推进系统的实时诊断。诊断结果表明,建立的推进系统模型是准确可靠的,开发的诊断系统能有效地找出故障组件并确定故障组件的状态。     

Monitor system design of distributed wind turbine-energy storage system

风储互补配合是提高风电质量、增加风电可控性、解决风电并网问题的有效途径。本文对“一机一储”的分布式风储系统进行了分析,探讨了分布式风储系统设计的整体方案,对风储能量管理系统监控后台的数据记录、监控界面和报表生成等进行了功能设计。风储系统实际运行效果表明,该监控后台能够很好地实现监控显示、历史数据记录、运行模式设定、统计分析和报表生成等功能,系统运行可靠,可为风储系统的推广应用提供一定的参考。     

Artificial immune system for fixed head hydrothermal power system

This paper presents artificial immune system for optimal scheduling of thermal plants in coordination with fixed head hydro units. Numerical results of two test systems have been presented to demonstrate the performance of the proposed algorithm. The results obtained from the proposed algorithm are compared with those obtained from differential evolution, particle swarm optimization and evolutionary programming technique. From numerical results, it is found that the proposed artificial immune system based approach is able to provide better solution than differential evolution, particle swarm optimization and evolutionary programming in terms of minimum cost and computation time.     

Performance analysis of thermal energy system with linear system method

The paper addresses the system performance of coal-fired power unit with changed auxiliary system or other localheat disturbance.The idea of state space model is imported and the universal formula for the calculation of sys-tem performance output is deduced on the system state equation.Two important vector of system are worked outunder linear system assumption and transform.The transfer matrix is the characteristics of system itself and isconstant for a similar condition,which greatly facilitates the analysis.The concept of thermal disturbance vectoris proposed to construct the thermal disturbance input easily.The method can be helpful for analyzing any ther-mal disturbance input satisfying the assumption and also for supplementing the correction means of performancetest.An example of 600MW power unit is presented to demonstrate its availability.     

Artificial neural network power system stabilizers in multi-machinepower system environment

The effectiveness of an artificial neural network (ANN), functioning as a power system stabilizer (PSS), in damping multi-mode oscillations in a five-machine power system environment is investigated in this paper. Accelerating power of the generating unit is used as the input to the ANN PSS. The proposed ANN PSS using a multilayer neural network with error-backpropagation training method was trained over the full working range of the generating unit with a large variety of disturbances. The ANN was trained to memorize the reverse input/output mapping of the synchronous machine. Results show that the proposed ANN PSS can provide good damping for both local and inter-area modes of oscillations     

Identification of system vulnerabilities in the Ethiopian electric power system

The Ethiopian Electric Power (EEP) has been operating and managing the national interconnected power system with dispersed and geographically isolated generators, a complex transmission system and loads. In recent years, with an increasing load demand due to rural electrification and industrialization, the Ethiopian power system has faced more frequent, widely spread and long lasting blackouts. To slash the occurrence of such incidents, identifying the system vulnerabilities is the first step in this direction. In this paper, the vulnerability assessment is performed using indices called active power performance index (PI_p) and voltage performance index (PI_v). These indices provide a direct means of comparing the relative severity of the different line outages on the system loads and voltage profiles. Accordingly, it is found that the most severe line outages are those lines that interconnect the high load centered (Addis Ababa and Central regions) with the rest of the regional power systems. In addition, the most vulnerable buses of the network in respect of voltage limit violations are mainly found at the high load centers.     

轮乘制下机车段修制度改革的探讨

通过对机车轮乘制下新的检修形势的分析,提出了确立以机车检查为主、修理为辅,检、修分离,检查范围模块化等建议;只有将机车检查从检修中分离和独立出来,才能真正保证轮乘机制下的机车质量.