太阳能驱动有机朗肯循环系统动态特性模拟与分析

发布时间：2018-04-09 19:57

本文选题：太阳能　切入点：有机朗肯循环　出处：《天津大学》2014年硕士论文

【摘要】：我国太阳能资源丰富,且资源丰富地区地广人稀,太阳能发电应用潜力巨大。但现阶段,由于缺乏高效的技术手段,加之太阳能本身能流密度低等缺点,使得太阳能利用率较低。有机朗肯循环(Organic Rankine Cycle,即ORC)具有循环效率高、蒸发压力和温度低等特点,是一种良好的中低品位能源利用技术与太阳能具有良好的匹配。因此,发展太阳能驱动有机朗肯循环发电技术,对缓解我国能源紧张,完善我国中低品位热能利用技术具有重要意义。本文在充分调研的基础上完成了200kW级有机朗肯循环发电系统的工况、设备选型以及系统设计并搭建了太阳能有机朗肯循环发电实验系统。系统包括热源环路、ORC环路、冷却环路等。采用R123为循环工质,以T-55导热油为热源,采用管壳式换热器,工质泵采用屏蔽泵。基于所设计的实际系统,本文建立了系统动态性能模型。以质量守恒方程、能量守恒方程为基础,利用分布参数法建立换热器模型。汽轮机与泵模型因响应远小于换热器而采用稳态模型,其出口参数分别由压比、扬程以及效率决定。基于建立的模型,设计了仿真模拟的研究方法,从模型参数、参数间关系和求解过程三个方面讨论了太阳能驱动ORC系统模型的求解方法。利用Simulink仿真平台,依据建立的模型和仿真模拟方法,构建了太阳能ORC系统各部件的仿真模块,并根据系统部件之间的耦合关系,将部件连接组合为动态系统模型。依据实验数据,对系统仿真模型进行了检验,并对系统在典型日标准工况下以及在云扰动和泵故障等非标准工况下,运行性能进行模拟。结果表明:(1)典型日条件下,系统主要部件热/电功率与太阳直射辐射量变化趋势相同,夏至日条件下,辐射对系统影响最大,蒸发器和冷凝器换热功率、汽轮机做功功率最大相对变化量分别为18.2%、18.0%以及18.4%,而最大效率变化仅为2.3%;(2)太阳能辐射阶跃导致的热源温度阶跃与系统响应时间呈线性关系,且云扰动对汽轮机的影响分别较蒸发器和冷凝器多2.21%和2.67%;(3)系统因导热油泵与冷却环路泵故障导致系统达到恶劣工况时间与流量阶跃量的倒数成线性关系,且冷却环路故障的响应时间远大于导热油本泵故障系统响应时间。
[Abstract]:Our country is rich in solar energy resources, and the area with rich resources is sparsely populated, so the application potential of solar power generation is huge.However, at present, due to the lack of efficient technical means, coupled with the low density of solar energy flow, solar energy utilization is low.Organic Rankine cycle of organic Rankine cycle (ORCs) has the characteristics of high cycle efficiency, low evaporation pressure and low temperature. It is a good low grade energy utilization technology and a good match with solar energy.Therefore, the development of solar energy driven organic Rankine cycle power generation technology is of great significance to alleviate the energy shortage and improve the utilization technology of medium and low grade thermal energy in China.In this paper, based on the full investigation, the operating conditions, equipment selection and system design of 200kW organic Rankine cycle power generation system are completed and the solar organic Rankine cycle power generation experimental system is built.The system includes heat source loop ORC loop, cooling loop and so on.Using R123 as circulating fluid, T-55 heat conduction oil as heat source, tube and shell heat exchanger and shielding pump as working fluid pump.Based on the designed system, the dynamic performance model of the system is established in this paper.Based on the mass conservation equation and the energy conservation equation, the heat exchanger model was established by using the distributed parameter method.The model of steam turbine and pump adopts steady state model because its response is much smaller than that of heat exchanger, and its outlet parameters are determined by pressure ratio, lift and efficiency, respectively.Based on the established model, the research method of simulation simulation is designed, and the method of solar-driven ORC system model is discussed from three aspects: model parameters, relationship between parameters and solution process.Based on the established model and simulation method, the simulation modules of each component of solar energy ORC system are constructed by using Simulink simulation platform. According to the coupling relationship between the components of the system, the components are connected and combined into a dynamic system model.Based on the experimental data, the simulation model of the system is tested, and the performance of the system is simulated under the typical daily standard operating conditions and the non-standard operating conditions such as cloud disturbance and pump failure.The results show that the thermal / electric power of the main components of the system is the same as that of the direct solar radiation under typical daily conditions. Under the Summer Solstice's condition, the radiation has the greatest influence on the system, and the heat transfer power of evaporator and condenser.The maximum relative variation of work power of steam turbine is 18.0% and 18.4%, respectively, while the maximum efficiency change is only 2.3g / 2) the temperature step of heat source caused by solar radiation is linearly related to the response time of the system.The effect of cloud disturbance on steam turbine is 2.21% and 2.67% more than that of evaporator and condenser, respectively.The response time of cooling loop fault is much longer than that of thermal oil pump fault system.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM617;TK519

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