共查询到18条相似文献,搜索用时 46 毫秒
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超临界二氧化碳布雷顿循环发电技术具有高效、清洁、结构紧凑等优点,是一种极具发展前景的新型发电循环。介绍了超临界二氧化碳布雷顿循环的特点、发展历史和国内外实验及示范项目,并探讨了5个核心研究方向的进展。 相似文献
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超临界二氧化碳布雷顿循环在能源领域的应用已经成为热门话题.依据超临界CO2布雷顿循环的基本原理,对其在不同能源领域应用的循环效率与传统的蒸汽工质进行比较.在火电领域应用效率提高较少,约2%~4%,但是建造成本也高出5%~8%;核电领域效率提升最明显,可以达到12%左右,应用前景最好;在太阳能发电领域中,虽然循环效率可以... 相似文献
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为了对超临界二氧化碳布雷顿循环发电系统热力学进行分析,首先构建了分流再压缩和一次再热耦合的超临界二氧化碳布雷顿循环系统主要关键部件的数学分析模型,并基于Matlab软件进行计算分析。分别讨论了系统主要关键参数对系统循环效率的影响。从仿真结果可以看出存在最佳的分流系数,最优的压缩机入口温度、压力和再热压力,使得循环系统具有较高的循环效率。最后为能够全面地反映系统综合性能,引入了遗传算法作为优化分析方法,研究多参数对系统循环效率的综合影响,得到最高效率点的最优关键参数。 相似文献
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超临界二氧化碳(S-CO2)布雷顿循环因其环保性与高热电转换效率而被视为核能发电未来发展的重要方向。借助Simulink软件平台,建立了S-CO2再压缩布雷顿循环闭环动态仿真系统,通过模拟结果与Sandia实验数据的比较,验证了系统模型的有效性。研究搭建的超临界CO2再压缩布雷顿循环系统在稳态设计点条件下的预测热效率为31.85%,此外,还获得了热源功率和流量扰动条件下系统热力学参数的响应特征,发现热源功率的变化促使系统效率单调提升或降低,而改变系统流量未呈现类似变化趋势;扰动施加过程中,循环系统的参数对热源功率的变化非常敏感,热源功率减小15.00%,循环效率从31.85%降低到22.00%。最终基于仿真结果,获得多参量耦合关联下的变化规律与调控策略,可为S-CO2再压缩布雷顿工程应用奠定基础。 相似文献
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为提高布雷顿循环热效率,在现有超临界二氧化碳布雷顿循环的基础上,提出一种基于回热技术的分级压缩与分级膨胀相结合的再压缩布雷顿循环方案,运用热力学计算软件EES对该循环参数进行热力学分析。结果表明,当分流系数约为0.47,透平入口温度为950 K,透平入口压力为29.0 MPa时,循环热效率为59%。当透平入口温度一定,分流系数在0.47~0.48时,循环热效率最高。在透平入口压力从20.0往29.0 MPa升高的过程中,最佳分流系数从0.39逐渐增加到0.47。在回热度从0.5增长到0.6的过程中,最佳分流系数从0.47增长到0.50。 相似文献
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针对再压缩式超临界二氧化碳布雷顿发电循环(S-CO_2),将有机朗肯循环(ORC)作为底循环用于回收系统余热,建立了S-CO_2/ORC联合循环。采用Aspen Plus建立分析模型,根据顶循环余热温度范围和安全环保要求,选取R245fa作为ORC系统工质,分析透平进口温度、透平进口压力及分流比对循环效率的影响,并通过分析耗能设备的功率变化找到影响系统效率变化的因素。结果表明:通过顶循环低温余热的回收利用,系统热效率提高4%以上;增大透平进口温度可提高顶循环的热效率,但对底循环热效率的影响较小;随着顶循环透平进口压力的增大,顶循环热效率增加而底循环热效率下降;在透平入口温度680℃、入口压力280 MPa的条件下,存在最优的再压缩循环分流比0.66使得联合循环热效率最高;使用ORC底循环回收顶循环余热,最高可以将系统热效率从50.3%提高到53.7%,联合系统可以获得6.7%的效率提升。 相似文献
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Designing new and efficient heat engines and increasing the efficiency of previous ones is one of the researchers’ interests in the field of thermodynamics. In this regard, what is mainly concerned is to design a cycle with the positive features of previous cycles, such as less pollution, and higher power‐to‐weight ratio and efficiency. One of these cycles is the supercritical carbon dioxide cycle (SCDC). The main goal of this research is designing a highly efficient SCDC with pessimistic and relatively optimistic efficiencies of 45% and 47%. This paper includes the complete first law analysis of the designed cycle, designing and discussion of efficiency improvement methods and comparison of SCDC with other power cycles. The sensitivity of the cycle efficiency to some important parameters has also been studied. 相似文献
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超临界CO2循环可以耦合较低温度的地热和较高温度的太阳能热组成混合热源发电系统。相比能量分析方法,火用分析方法更便于分析混合系统对提高能量利用率的作用,以及识别造成可用能损失的设备和过程。115℃地热和200℃地热分别与采用槽式聚光集热技术的太阳能热组成混合热源,构成简单回热超临界CO2循环。分析结果表明:混合系统的火用效率比单纯太阳能热的循环系统提高了5% ~ 10%;太阳能聚光集热器的?损失最大,占80%以上,其次是除预冷器以外的各类换热器以及透平;相比之下,压缩机和预冷器的火用损失较小。减少?损失的关键是提高太阳能聚光集热器和换热器的性能,包括提高集热管运行温度,以及提高换热器效能。 相似文献
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利用Aspen Plus软件分别构建了煤气化直接加热式和煤直接燃烧式sCO2动力循环系统模型,对空气分离装置(ASU)子系统、热力发电子系统和烟气净化压缩子系统进行耦合计算,并分析各主要参数对整体循环性能的影响规律.结果 表明:对于煤气化sCO2循环,在透平入口1150℃/30 MPa的参数条件下,系统净效率可达40.67%,同时可实现接近100%的碳捕集;在考虑系统整体能耗后,ASU出口O2存在最佳纯度,当O2纯度由95%增加至99.5%时,系统净效率由40.16%升高到40.67%;在相同关键循环参数条件下,由于取消了煤气化及合成气压缩装置,煤直接燃烧式sCO2循环的系统净效率相比煤气化直接加热式循环提高了7.54%. 相似文献
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The main compressor in a supercritical carbon dioxide(SCO2)Brayton cycle works near the critical point where the physical properties of CO2are far away from the ideal gas.To investigate the effectiveness of the conventional one-dimensional(1D)loss models for predicting the performance of compressors working in such nontraditional conditions,detailed comparisons of 1D predicted performance,experimental data and threedimensional CFD results are made.A 1D analysis method with enthalpy and total pressure based loss system is developed for multistage SCO2 centrifugal compressors,and it is firstly validated against the experimental results of a single stage SCO2 centrifugal compressor from the Sandia National Laboratory.A good agreement of pressure ratios with experiments can be achieved by the 1D method.But the efficiency deviations reveal the potential deficiencies of the parasitic loss models.On the basis of the validation,a two-stage SCO2 centrifugal compressor is employed to do the evaluation.Three-dimensional CFD simulations are performed.Detailed comparisons are made between the CFD and the 1D results at different stations located in the compressor.The features of the deviations are analyzed in detail,as well as the reasons that might cause these deviations. 相似文献
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《热科学学报(英文版)》2021,(1)
The main compressor in a supercritical carbon dioxide(SCO_2) Brayton cycle works near the critical point where the physical properties of CO_2 are far away from the ideal gas. To investigate the effectiveness of the conventional one-dimensional(1D) loss models for predicting the performance of compressors working in such nontraditional conditions, detailed comparisons of 1D predicted performance, experimental data and threedimensional CFD results are made. A 1D analysis method with enthalpy and total pressure based loss system is developed for multistage SCO_2 centrifugal compressors, and it is firstly validated against the experimental results of a single stage SCO_2 centrifugal compressor from the Sandia National Laboratory. A good agreement of pressure ratios with experiments can be achieved by the 1D method. But the efficiency deviations reveal the potential deficiencies of the parasitic loss models. On the basis of the validation, a two-stage SCO_2 centrifugal compressor is employed to do the evaluation. Three-dimensional CFD simulations are performed. Detailed comparisons are made between the CFD and the 1D results at different stations located in the compressor. The features of the deviations are analyzed in detail, as well as the reasons that might cause these deviations. 相似文献