【作者】 崔映红；

【导师】 杨勇平；

【作者基本信息】 华北电力大学（北京） ， 热能工程， 2009， 博士

【摘要】 节能降耗是我国的长期基本国策。作为全国煤炭消耗大户,火力发电厂的节能任务意义重大。太阳能辅助燃煤一体化发电系统是在常规燃煤机组设计框架的基础上,合理集成太阳能热利用系统的发电技术,为火电机组的技术节能和太阳能大规模利用提供了方向。本学位论文依托国家自然科学基金项目“太阳能与化石燃料一体化发电系统耦合机理与热力特性研究”等科研任务,原创性地提出太阳能辅助燃煤发电系统,并以此为核心,开展了以下研究:进行了利用抛物面槽式集热器收集太阳能热量,与燃煤机组集成为太阳能辅助燃煤发电系统的研究。探讨了影响DSG集热器热效率的因素并进行了分析。考虑沿着流体流动方向温度的变化,建立了集热器稳态传热模型;对集热器内流体流动压降的计算和影响因素进行了研究。探讨了太阳能热发生系统与燃煤发电系统之间能量流、物质流的不同耦合方式及典型组态。基于燃煤机组的变工况理论,建立了一体化发电系统拓扑结构与参数的综合集成优化模型,并利用热力学第一定律、第二定律(火用方法)和火用经济学方法对一体化发电系统进行热力性能分析与计算,探讨了不同集成方式、太阳能集热器场不同热力参数、燃煤机组容量大小及其是否进行结构变动等因素对一体化发电系统经济性能的影响,总结了一体化发电系统的集成规律;研究了外部键系数的计算方法,进行了不同容量燃煤机组不同流的外部键系数计算,基于火用的不等价性,探讨了太阳能辅助燃煤一体化发电系统的耦合机理。建立了一体化发电系统的热力性能分析模型。分析了一体化发电系统的热力性能并计算了在我国拉萨、呼和浩特地区一体化发电系统的热发电成本。结果表明:在与国产300MW燃煤机组集成为一体化发电系统时,拉萨地区的太阳能热发电成本为:0.57元/kW·h;如与国产600MW燃煤机组集成,呼和浩特地区的太阳能热发电成本为:0.750元/kW·h。在我国存在与其他可再生能源发电技术发电成本基本相当的区域。太阳能辅助燃煤一体化发电技术为我国燃煤机组的技术节能和太阳能资源的规模利用开辟了一条新的途径,具有良好的发展前景。更多还原

【Abstract】 Energy conservation & consumption reduction is one of the long-time basic national policies in China.As the annual coal consumption in coal-fired plants accounts for much of the whole coal consumption in the country,energy conservation & consumption reduction in them plays a significant role.Solar supported coal-fired electric generation(SSCEG) system,which is based on the design framework of a conventional coal-fired generation unit,integrates a solar thermal utilization system into the coal-fired generation system.It opens a way for energy conservation technically in coal-fired power plants and for large-scale utilization of solar energy. Supported by some scientific tasks including the National Natural Science Foundation of China named as "Research on Coupling Mechanisms & Thermal Characters of the Integrated Thermal Electric Generation System Combined by Solar Energy and Fossil Fuel" and others,the SSCEG system has been put forward originally in this dissertation.And the work carried out in this dissertation all takes this SSCEG system as the core.The main work is as follows:Firstly,parabolic trough solar collectors are used to collect solar energy in a SSCEG system.The factors affecting the thermal efficiency of a DSG collector was discussed and analyzed.And the stable thermal conduction model was established as fluid temperature changes along fluid flowing.The calculation and the affecting factors of fluid flowing pressure drops through the collector absorber pipe were studied.Integration schemes of energy fluxes and mass flows between solar utilization subsystem and coal-fired generation subsystem were put forward.And some typical SSCEG systems were given.Based on the varying operation theories of the coal-fired plant,the integration model of optimizing topological structure and parameters of a SSCEG system was set up.And the thermal performance of the optimum SSCEG system was analyzed and calculated by applying the theory of the first law,the second law and thermo-economic analysis method on it individually.Then the effects on economic performance of integration scheme,thermal parameters of the solar field,capacity of the coal-fired power unit and whether the structure of the coal-fired unit changing or not were discussed.Finally,integration rules were summarized.Calculation method of coefficient of extemal bonds(CEB) was discussed,and the CEBs of different flows in different coal-fired units were obtained.Then the coupling mechanism of the SSCEG was researched based on the non-equivalence performance of exergy.Thermodynamic analysis model of a SSCEG system was set up.Then the thermal performance of the SSCEG system was analyzed and its unit electricity generation cost was calculated by applying the model in Lhasa and Hohhot in China.And the results show that,in Lhasa,the solar thermal electricity generation cost of the SSCPG system integrated with the national 300MW coal-fired generation is 0.57￥/kW·h.And it is 0.75￥/kW·h when integrated with the national 600MW units in Hohhot.There exist regions where the electricity generation cost of using solar thermal is equivalent to that of using other renewable energy in China.So the SSCEG technology is a promising way for energy conservation technically of cola-fired power plants and the large-scale utilization of solar energy in China.更多还原