【作者】 张新敬；

【导师】 谭春青； 陈海生；

【作者基本信息】 中国科学院研究生院（工程热物理研究所） ， 动力机械及工程， 2011， 博士

【摘要】 当前,电力的消耗量持续增长,但是电力的生产能力以及输运网络的建设等的发展相对滞后；可再生能源(风能、太阳能等)电力在总的电力供应中的份额逐渐增加,但是可再生能源的发电存在固有间歇性的缺点；在用户侧,电力的消耗在一天中并不是恒定的,具有能耗的峰值和低谷等,这些问题增加了目前电力系统的复杂性以及不安全性。迫切需要引进新技术来解决电力生产、输运、消耗过程中面临的问题。电力储能系统通过一定介质存储电能,在需要时将所存能量释放发电。发展电力储能系统是解决目前可再生能源大规模利用瓶颈的迫切需要,也是提高常规电力系统效率、安全性和经济性的有效途径和发展分布式能源系统的关键技术。本文研究了基于压缩空气的储能系统的性能。该技术以压缩空气的形式存储用电低谷时的盈余电力或者来自可再生能源的电力；当用电高峰时,压缩空气吸收外界热量,膨胀做功产生电力,满足用电高峰需要。本研究首先回顾了压缩空气储能技术的研究进展,并进行了压缩空气储能系统的热力学分析,对比分析了不同类型的压缩空气储能技术的性能,为发展该技术提供参考。为了进一步探讨压缩空气储能存在的问题以及高压、绝热或者辅助热源的条件下的系统性能,研究者设计并搭建了小型压缩空气实验台。实验台主要包括高压压缩机、高压储气罐、加热器、膨胀机、动力测试系统以及数据采集系统。实验中,通过一台多级、往复式压缩机得到260bar的高压压缩空气,如果不计及压缩热存储,压缩机的效率在30%～43%之间,如果计及压缩热的回收,其效率将达到42～65%。以储气罐为研究对象,整个储能过程是一个变压的过程,储能过程的效率为25%～35%(不计及压缩热存储)；如果存储压缩热,那么其效率将为35%～60%。膨胀机的出功在200～1650W之间,其气动效率为10%～35%。由于本实验采用的压缩机、膨胀机等部件的效率不太高,因此系统的总体效率不高,储气压力和膨胀压力对系统总体性能的影响不明显。依据实验结果,本研究讨论了提高储能系统总体性能的几种方法：①选用或者设计适合于本实验的高效率压缩机和膨胀机将可以大幅度提高压缩空气储能系统的性能,储能效率最大可以在65%以上。②储能过程中多级压缩机设计为变压工作模式,取代多级压缩机恒压工作、变压储气过程,将可以相对节省压缩空气过程能量；释能过程中,如果选用变压比的膨胀机,取代恒压工作的多级膨胀机,那么释能过程将可以使系统总输出功相对增加。③通过与常规动力系统相耦合,形成混合动力系统,可以增加储能系统的输出功,提高其效率。并且混合动力系统具有较高的总体效率,最大增幅在10%以上,提高了传统动力系统的燃料利用率,降低单位出功的温室气体排放,降幅可达40%以上。本部分的研究表明,压缩空气/液氮储能系统具有较好的工作性能和较强的应用灵活性,是一种值得研究和发展的能源动力系统。本文最后给出了结论和展望,提出了进一步开展压缩空气储能系统研究工作的重点。更多还原

【Abstract】 Nowadays, there is a growing demand in electricity, while the corresponding request of electrical production and the transmission grid construction are lagged far behind. The percentage of the renewable energy (solar energy, wind energy, etc.) in the total power production is growing, but it comes along with inherent drawbacks, such as fluctuation and intermittence. On the customer side, the electricity consumption is not constant within a day or a week, in which there are peak and off-peak durations. All these problems make current electricity system complicated and unsafe. It is in great demand to introduce Electrical Energy Storage (EES) technology to solve the problems generating in the processes of electricity production, transmission and consumption. EES refers to a process of converting electrical energy from a power network into a form that can be stored for converting back to electrical energy when needed. The development of EES is a key way to break the bottleneck of the use of renewable energy in a large scale, and it also could increase the traditional power system efficiency, security and economy, and enhance the utility of distributed generation system.In this dissertation, the performance of the energy storage system based on compressed air is studied. With this system, the off-peak electricity from either traditional power plant or renewable energy plant is stored in a form of compressed air by high pressure compressor. After a certain time, when the electricity is in peak demand, the compressed air is released, then absorbs some heat, and drives an expander to generate power, which will feedback to the grid. Firstly, the research progress of Compressed Air Energy Storage (CAES) system is reviewed. Some research topics are highlighted, such as high pressure, thermal energy storage. And then, the thermodynamic analysis and comparisons are made among three configurations of CAES system, which provides a reference for CAES development.An experimental system is set up to explore further the performance of the CAES system, especially on high pressure, thermal storage etc.. The rig is made up of a high pressure compressor, high pressure cylinders, an electrical heater, an expander, a power measurement system and data acquisition system. This system was run successfully in a laboratory, which indicates the feasibility of lab-scale CAES system with high pressure. In experiments, the air could be compressed to be as high as260bar. The efficiency is in the range of30%～43%without compressed heat storage, while it could be35%～63%if the heat is taken into account. The pressure during energy storage process is changeable in cylinders, and the process efficiency is about25～35% (without compressed heat storage) or35～60% (with compressed heat storage). The power output of the expander is in the range of200-1650W, and the efficiency is about10～35%. The total system efficiency is not high due to compressor and expander efficiencies are not very good, and as a result the storage and expansion pressures do not affect the whole system too much.Based on the experimental analysis, some solutions to improve the whole system efficiency are discussed,(i) It could increase the storage system performance significantly by using more suitable components such as compressor and expander with high efficiencies. The round trip efficiency of the storage system can be above65%.(ii) During the energy storage process, the compressor chain works in a ramping pressure mode instead of the normal one in series mode with constant pressure output could decrease total relative compression energy consumption. During the energy discharging process, the expander chain works in a sliding mode instead of the normal one in series mode with constant pressure inlet could increase relative total energy output.(iii) It can also increase the power output and efficiency to couple the storage system with traditional power systems such as diesel engine as a hybrid power configuration. The maximum efficiency of the hybrid systems could be increased more than10%. The relative Greenhouse Gas (GHG) emission of these two hybrid system are quite lower, which could be40%less than that of diesel engine only. This research indicates the hybrid systems enjoy better performances and flexibility, and present the promising development.In the final part, the conclusion and future research prospects are drawn.更多还原