西北地区规模化养殖场热电联产系统性能优化研究

发布时间：2019-03-08 18:12

【摘要】：畜禽养殖业的规模化带来了不可忽略的环境污染问题。沼气工程将养殖场产生的粪污进行厌氧发酵,既解决了环境污染问题,又得到了可利用能源,具有重要的推广意义。但是,西北地区冬季寒冷漫长,导致大多沼气工程在实际运行中普遍存在产气率低和产气量不稳定的现象。本文基于对兰州花庄大型沼气发电工程的实地调研,对该工程运行9年以来的整体性能进行了分析,并总结了沼气发电工程实际运行所遇到的问题。为了解决花庄沼气工程发酵温度不稳定、系统运行连续性差等问题,整合太阳能集热系统、恒温厌氧发酵系统、内燃机发电系统和沼气锅炉热利用系统,构建了一套多种可再生能源耦合的新型热电联产系统,并从经济性、节能性、环保性等方面对新系统进行了全面的评价。主要研究内容和结果如下:(1)系统的初始工艺符合实际工程,9年运行期内系统基本能够稳定运行,具有可推广性;累计收益239.1万元,节省标煤1724吨,减少CO2排放4211吨;政策扶持力度不够、工程配套装备质量差和运行管理不规范等因素是造成工程后期运行效果差、综合效益没有最大化以及企业主体缺乏积极性的关键原因。(2)针对现在沼气工程存在的问题,本文整合太阳能集热系统、恒温厌氧发酵系统、内燃机发电系统和沼气锅炉热利用系统,构建了多能互补的热电联产系统。以兰州花庄奶牛场的实际情况为基础,对现有系统进行优化,构建一套太阳能—沼气锅炉—发电余热耦合的新型热电联供系统,并对新系统的关键部分进行了设计和选型。(3)优化后的系统年产气量达到51.9万m3,增幅比达到400%;优化后系统年发电量达到71.3万k Wh,增幅比达到390%,占全年养殖场用电量的70.2%;系统年增益为24.9万元,静态投资回收期为1.1年;改进后的系统具有良好的经济效益、社会效益和环境效益。(4)优化后的各个子系统的?成本差均不大,整个系统的能量转换效率比较高,经过热电联产优化后系统具有较优的热经济性;优化后系统总?效率在20%~33%之间,冬季较小,夏季最大,春秋季位于其间;优化后的系统全年产出的?经济系数为0.417元/k Wh,大大低于市场电价,说明该养殖场采取这种模式运行的热电联产系统是切实可行的。本文的创新点:(1)改进和优化了热电联产系统,使西北地区规模化养殖场的沼气发电工程连续、稳定、高效运行。(2)基于西北地区的气候条件和规模化养殖场的能源特点,对新系统进行不同运行策略的分析,并通过采用热经济分析,实现了综合效益的最大化。
[Abstract]:The large-scale livestock and poultry breeding industry has brought about environmental pollution problems that can not be ignored. Biogas project not only solves the problem of environmental pollution, but also obtains the available energy, which is of great significance for the promotion of anaerobic fermentation of faeces produced in farms. However, the cold and long winter in Northwest China leads to the low gas production rate and unstable gas production in the actual operation of most biogas projects. Based on the on-the-spot investigation of large-scale biogas power generation project in Huazhuang, Lanzhou, this paper analyzes the overall performance of the project since its operation for nine years, and summarizes the problems encountered in the actual operation of the biogas power generation project. In order to solve the problems of unstable fermentation temperature and poor continuity of the system in Huazhuang biogas project, the solar energy collector system, the constant temperature anaerobic fermentation system, the internal combustion engine power generation system and the biogas boiler heat utilization system are integrated. A new type of heat and power co-generation system coupled with various renewable energy sources has been constructed, and the new system has been comprehensively evaluated from the aspects of economy, energy conservation and environmental protection. The main research contents and results are as follows: (1) the initial process of the system accords with the actual project, and the system can run stably and can be extended during the nine-year operation period; Cumulative income of 2.391 million yuan, saving 1724 tons of standard coal, reducing CO2 emissions by 4211 tons; Such factors as insufficient policy support, poor quality of engineering supporting equipment and non-standard operation management are the causes of poor operation effect in the later stage of the project. The key reason is that the comprehensive benefit is not maximized and the enterprise main body lacks enthusiasm. (2) in view of the problems existing in the biogas project, this paper integrates the solar energy collector system, the constant temperature anaerobic fermentation system, and so on. Internal combustion engine power generation system and biogas boiler heat utilization system are used to construct multi-energy complementary heat and power co-generation system. Based on the actual situation of Lanzhou Huazhuang dairy farm, this paper optimizes the existing system and constructs a new type of combined heat and power supply system, which is coupled with solar energy, biogas boiler and waste heat of power generation. The key parts of the new system are designed and selected. (3) the annual gas production of the optimized system reaches 519000 m3, with an increase ratio of 400%; After optimization, the annual power output of the system increases by 390% to 713000 k Wh, accounting for 70.2% of the annual farm electricity consumption, the annual gain of the system is 249000 yuan, and the static investment recovery period is 1.1 years. The improved system has good economic, social and environmental benefits. (4) the optimized subsystems? The cost difference is not big, the energy conversion efficiency of the whole system is relatively high, after optimization of cogeneration, the system has better thermal economy. Efficiency is between 20% and 33%, winter is small, summer is the largest, spring and autumn is in the middle; optimized system output for the whole year? The economic coefficient of 0.417 yuan / k Wh, is much lower than the market price, which shows that it is feasible for the farm to adopt this mode of co-generation system. The innovation of this paper is as follows: (1) improve and optimize the co-generation system of heat and power, make the biogas power generation project of large-scale farm in Northwest China continuous and stable. (2) based on the climatic conditions in northwest China and the energy characteristics of large-scale farms, the new system is analyzed with different operation strategies, and the comprehensive benefit is maximized by using thermal economic analysis.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM61;S216.4

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