基于干工质的有机朗肯循环参数优化及太阳能热发电系统设计

发布时间：2018-04-16 18:43

本文选题：有机朗肯循环 + 有机工质　；参考：《华中科技大学》2014年硕士论文

【摘要】：当前能源政策与形势下，新能源技术得到大力发展，应用范围也逐渐扩大。太阳能发电技术为新能源中较有竞争力的技术之一，其中太阳能热发电技术也得到进一步发展。目前，槽式太阳能集热技术最为成熟，为发电循环提供中温热源。与传统水蒸汽朗肯循环相比，有机朗肯循环利用低沸点有机工质进行发电循环，在中温热源下效率更为可观，，系统形式简单，初期投资小。本文根据槽式太阳能热源温度范围100~400℃，选取常用作工质的R245fa、正戊烷、甲苯、MDM与D4进行分析与研究。利用MATLAB与NIST Refprop编制应用单级汽轮机的基本有机朗肯循环系统与带回热有机朗肯循环系统的计算程序，选取的5种工质，分析了5种工质在两种循环系统中的工作性能，结果表明R245fa适用于低于150℃的运行温度，且R245fa基本有机朗肯循环热效率很可观。正戊烷从循环性能分析可用于接近300℃高温，但受其自燃温度限制，最好用于250℃左右运行温度。甲苯、MDM与D4循环性能依次递减，但是适用的运行温度依次升高，其中MDM与D4使用回热器的循环性能比基本循环要提高一倍。通过对5种工质的分析，选取温度和循环性能较好的甲苯与MDM，建立了太阳能有机朗肯循环发电系统模型，对不同运行参数下太阳能有机朗肯循环发电系统性能分析得出循环最高温度300℃时，MDM蒸发压力为1MPa时循环性能最好，甲苯则在蒸发压力为2.3MPa时系统综合性能最好。两种工质共同的运行特征是排气参数较高，因而造成冷凝器火用损失较大。且在对蒸发系统各换热段换热器KA系数的计算和分析中发现，MDM液态和过热蒸汽状态的升温过程需要较多能量和较大的换热面积，反而蒸发段需要能量较少，甲苯则在蒸发段需要最多的能量和换热面积。综合各项参数，甲苯在太阳能有机朗肯循环系统中工作性能优于MDM。根据计算所得甲苯与MDM最优运行参数，对系统中主要换热器进行设计计算，为实际系统设备研发提供参考。
[Abstract]:The current energy policy and situation, new energy technology has been developed rapidly and has gradually expanded the scope of application of solar power technology. As one of the new energy more competitive technology, including solar thermal power generation technology has been further development. At present, groove type solar thermal technology is the most mature generation cycle provides a medium temperature heat source compared with the traditional steam Rankine cycle, Rankine cycle using low boiling point organic working fluid of the heat source in the power cycle, the efficiency is even more impressive, the system has simple form, the initial investment is small.
According to the trough type solar heat source temperature range of 100~400 DEG C, select the commonly used refrigerant R245fa, pentane, toluene, MDM and D4 were analyzed and studied. By using MATLAB program and NIST Refprop for application of single stage steam turbine basic organic Rankine cycle system and regenerative organic Rankine cycle system, 5 kinds of refrigerant selected 5, work performance in the two cycle system is analyzed, results show that R245fa is suitable for operating temperature below 150 DEG C, and the R245fa basic organic Rankine cycle thermal efficiency is considerable. Pentane from cycle performance analysis can be used to close to the high temperature of 300 DEG C, but its ignition temperature limit, the best for 250 DEG C about the operation temperature. Toluene, cycle performance of MDM and D4 are decreased, but the applicable operating temperature gradually increased, the MDM and D4 using cyclic regenerator performance than the basic cycle to be doubled.
Through the analysis of 5 kinds of refrigerants, selection of toluene and MDM temperature and good cycle performance, established solar organic Rankine cycle power generation system model, the performance of the solar organic Rankine cycle power generation system under different operating parameters of maximum cycle temperature of 300 DEG C, MDM evaporation pressure is 1MPa the best cycle performance, in toluene the evaporation pressure is 2.3MPa the best comprehensive performance of the system. Two kinds of common operating characteristics of refrigerant exhaust parameters is higher, resulting in condenser exergy loss greatly. Found the calculation and analysis of heat exchanger and KA coefficient of the evaporation system in each heat exchanger in the heating process of MDM liquid and superheated steam state needs more energy and the larger heat transfer area, but the evaporation section needs less energy, toluene requires most energy and heat transfer area in the evaporation section. The parameters of toluene in solar organic Rankine The performance of the circulating system is better than that of MDM.. According to the optimal operation parameters of toluene and MDM, the design and calculation of the main heat exchangers in the system are carried out, providing a reference for the research and development of the actual system equipment.

【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM615

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