干旱区生态环境知识资源中心(Arid): CO2-TiCl4 working fluid for high-temperature heat source power cycles and solar application

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DOI	10.1016/j.renene.2018.10.018
	CO2-TiCl4 working fluid for high-temperature heat source power cycles and solar application
	Bonalumi, D.; Lasala, S.; Macchi, E.
通讯作者	Bonalumi, D (corresponding author), Politecn Milan, Energy Dept, Via Lambruschini 4, I-20156 Milan, Italy.
会议名称	4th International Seminar on Organic Rankine Cycle Power Systems (ORC)
会议日期	SEP 13-15, 2017
会议地点	Politecnico Milano Bovisa Campus, Milano, ITALY
英文摘要	The application of CO2 power cycles has proved to be particularly advantageous to exploit high-temperature heat sources (500-800 degrees C) in the case of available low-temperature heat sinks (15-25 degrees C). Otherwise, the efficiency of these cycles is strongly reduced when cold sink temperatures are higher than 25 degrees C. This is the case, for example, of solar applications installed in desert areas whose cold sink is represented by available hot air. Due to these high temperatures of the cold sink, CO2 is inevitably compressed in the supercritical phase thus preventing its more efficient pressurization in the liquid phase. One of the solutions envisaged to overcome this problem consists of adding to CO2 a small amount of one or more chemicals, resulting in a mixture with a critical temperature higher than the one of pure CO2 (about 31 degrees C). This preserves the working fluid compression in its liquid phase, even in the case of cold sinks with temperatures greater than 25 degrees C. This research aims to show that the addition to CO2 of a specifically selected second component enables to increase the critical temperature up to 45 degrees C with relevant improvements of cycle efficiency with respect to pure-CO2 power cycles. In particular, after summarizing the most relevant criteria to be accounted for when selecting CO2-additives, the paper warns about the thermodynamic effects deriving from adding to CO2 a second component characterized by a much more high critical temperature, such as the occurrence of infinite-pressure critical points and multiple-phase liquid-liquid and vapor-liquid critical points. Moreover, the paper specifically analyses the thermodynamic properties of CO2-TiCl4 mixtures which, depending on the content of TiCl4, may lead to a mixture characterized by the sought higher critical temperature. While studying this mixture, it has been observed that it presents multiple-phase critical points. For the sake of completeness, the paper also shows how do enthalpy and specific volume change in response to pressure variations in the event of either liquid-liquid or vapor-liquid critical points. This research finally shows the comparison between performances of power cycles which use, as working fluid, either pure CO2 or the specifically designed CO2-TiCl4 mixture. As expected, the TiCl4 addition brings about a significant efficiency gain. (C) 2018 Elsevier Ltd. All rights reserved.
英文关键词	Rankine cycle Supercritical CO2 Molten salt Liquid metal TiCl4 Solar plant
来源出版物	RENEWABLE ENERGY
ISSN	0960-1481
出版年	2020
卷号	147
页码	2842-2854
出版者	PERGAMON-ELSEVIER SCIENCE LTD
类型	Article; Proceedings Paper
语种	英语
国家	Italy;France
收录类别	CPCI-S
WOS记录号	WOS:000504514700005
WOS关键词	ORGANIC RANKINE CYCLES ; TITANIUM TETRACHLORIDE ; GENERATION ; SELECTION ; MIXTURES ; SYSTEMS ; PLANT ; PURE
WOS类目	Green & Sustainable Science & Technology ; Energy & Fuels
WOS研究方向	Science & Technology - Other Topics ; Energy & Fuels
资源类型	会议论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/313871
作者单位	[Bonalumi, D.; Macchi, E.] Politecn Milan, Energy Dept, Via Lambruschini 4, I-20156 Milan, Italy; [Lasala, S.] Univ Lorraine, Lab React & Genie Proc, 1 Rue Grandville, F-54000 Nancy, France
推荐引用方式 GB/T 7714	Bonalumi, D.,Lasala, S.,Macchi, E.. CO2-TiCl4 working fluid for high-temperature heat source power cycles and solar application[C]:PERGAMON-ELSEVIER SCIENCE LTD,2020:2842-2854.