喷射器升压式有机朗肯循环及其气液两相喷射器性能研究

发布时间：2018-03-18 00:17

本文选题：有机朗肯循环　切入点：喷射器　出处：《广西大学》2015年硕士论文　论文类型：学位论文

【摘要】：有机朗肯循环系统在低品位能源的利用中具有良好的表现,在严峻的能源形势下有机朗肯循环系统的研究和应用备受关注。气液两相喷射器是一种特殊的流体输送装置,它使气态和液态两股流体在其特殊的流动通道内进行质量、动量、能量的交换,产生凝结激波,在喷射器出口获得压力均高于两入口压力的液态工质。喷射器无运动部件、无噪音、无泄漏,应用于有机朗肯循环中取代传统的机械升压泵,无需外力驱动,可以提高循环系统的能源利用率。本文以喷射器升压式有机朗肯循环为研究对象,即将气液两相喷射器应用于有机朗肯循环中构成喷射器-汽轮机有机朗肯循环、将喷射器和液轮机取代传统有机朗肯循环中的工质泵和汽轮机构成喷射器-液轮机有机朗肯循环,克服工质泵和汽轮机占地面积大、泄漏、操作复杂等缺点。对两种新的有机朗肯循环系统和传统有机朗肯循环的火用效率与热效率进行了理论计算和分析,分析喷射器对系统性能的影响作用。结果表明,在相同的蒸发器出口条件下,喷射器与汽轮机结合的有机朗肯循环系统在三种系统中具有最高的火用效率和热效率,分别为58.11%、15.9%；喷射器与液轮机结合的有机朗肯循环系统的火用效率不超过50%、热效率在14%以下,虽然能源利用效率低,但是该系统可以应用在一些移动设备和空间有限的场合。喷射器与汽轮机结合的有机朗肯循环系统的火用效率和热效率较高,具有良好的应用前景。研究内容为低品位能源的利用提出了一种新的发展思路。在喷射器与汽轮机结合的有机朗肯循环系统中,研究了该系统使用干工质、湿工质和等熵工质时的系统性能。结果表明,使用等熵工质时,喷射器与汽轮机结合的有机朗肯循环系统热效率最高,为18.0%,系统输出净功较大,为486.55kW；系统使用干工质时由于汽轮机排汽温度高,增加了工质在冷凝器中的能量损失从而降低系统热效率,而且影响部件使用寿命；使用湿工质时,系统的输出净功最小、热效率最低。搭建了喷射器性能实验台架,使用有机工质R141b对喷射器进行实验,考查了喷射器的升压能力和引射系数能达到的范围。实验中喷射器出口压力低于蒸气压力,引射系数较小。实验表明,当使用有机工质时,要实现喷射器的升压能力、达到较大的引射系数还要对喷射器进行更为严格的设计和更为完善的实验操作。本文研究得到国家自然科学基金资助项目(NO.51266001)的支持。
[Abstract]:Organic Rankine cycle system has good performance in the use of low grade energy, has attracted much attention in the research and application of organic Rankine cycle system the severe energy situation. The two-phase ejector is a special fluid conveying device, it makes the gaseous and liquid two fluid quality, in its special flow channel the momentum, energy exchange, condensation shock is generated in the liquid refrigerant, the injector outlet pressure is higher than two. The entrance pressure ejector with no moving parts, no noise, no leakage, applied to the organic Rankine cycle to replace the traditional mechanical booster pump, without external force, can improve the circulation system of energy utilization rate. In this paper the ejector boost organic Rankine cycle as the research object, the gas-liquid two-phase ejector for organic Rankine cycle in a jet turbine organic Rankine cycle, the injector and the The hydraulic turbine to replace the traditional organic Rankine cycle in the refrigerant pump and turbine of injector hydraulic turbine organic Rankine cycle, steam turbine and pump overcome refrigerant leakage, covers an area of large, complex operation shortcomings. The exergy efficiency and heat efficiency of two kinds of organic Rankine cycle system and the traditional theory of organic Rankine cycle the calculation and analysis, analysis of ejector effect on the system performance. The results show that the outlet of the evaporator in the same conditions, injection of organic Rankine cycle system and steam turbine combined with the highest thermal efficiency and exergy efficiency of the three systems, respectively, 58.11%, 15.9%; exergy efficiency of jet reactor and organic Rankine cycle system the hydraulic turbine with no more than 50%, the thermal efficiency is below 14%, while the low efficiency of energy use, but the system can be used in a number of mobile devices and the limited space of a jet. Organic Rankine cycle system and steam turbine combined with the exergy efficiency and heat efficiency is high and has good application prospects. Put forward a new development idea of content for the utilization of the low grade energy. In organic Rankine cycle system and steam turbine combined with the ejector, studied the use of dry refrigerant in the system, wet work matter and isentropic refrigerant system performance. The results show that the use of isentropic refrigerant, the ejector and the steam turbine combined organic Rankine cycle system the highest thermal efficiency is 18%, the output of the system, the net work is large, 486.55kW system; use dry refrigerant due to steam turbine exhaust temperature is high, increasing the energy loss the refrigerant in the condenser so as to reduce the heat efficiency of the system, but also affect the service life of the components; the use of wet refrigerant, the output of the system net power minimum, the minimum thermal efficiency. Build the ejector performance test bench, using organic Refrigerant R141b experiment on injector, examine the ability for injection booster and ejection coefficient can reach the range. The injector outlet pressure in the experiment is lower than the vapor pressure, ejector coefficient smaller. Experiments show that when using organic refrigerants, to achieve the injection boosting capability is reached, ejector coefficient larger also on the injector for more stringent design and more perfect experimental operation. This study was supported by the National Natural Science Foundation (NO.51266001) support.

【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK26

【参考文献】