Unsteady flows of a scroll expander under various types of expansion process

doi:10.12028/j.issn.2095-4239.2019.0119

Abstract

Abstract: This study was expected to provide the theory references for the design of a scroll expander used in micro-compressed air energy storage (micro-CAES) systems, by conducting the computational fluid dynamics (CFD) method to obtain the pressure, velocity and temperature field distributions in the working chambers. The effects of different external expansion ratio on the transient performance of the scroll expander and the flow fields of the working chambers were investigated under a constant back-pressure. The results showed that the variable external expansion ratio has little influence on the fluctuation of the inlet mass flow rate, and the outlet mass flow rate fluctuation increases with the increase of the external expansion ratio. The heat utilization degree of the compressed air in the expander and the unsteady driving moment of the expander increase with the increase of the external expansion ratio. The secondary flow loses in the back pressure chamber also increase with the increase of the external expansion ratio. There exist obvious local high temperature areas in the back pressure chamber.

Key words: micro-CAES, scroll expander, unsteady flow, external expansion ratio, numerical simulation

CLC Number:

TH45

LIU Zhen, WU Huawei, LIN Xin, SONG Panpan. Unsteady flows of a scroll expander under various types of expansion process[J]. Energy Storage Science and Technology, 2019, 8(6): 1241-1246.

References

[1] 宋洁, 赵波, 梁丹曦, 等. 压缩空气膨胀发电系统最大效率跟踪控制策略[J]. 储能科学与技术, 2017, 6(1):154-161. SONG Jie, ZHAO Bo, LIANG Danxi, et al. Strategy for tracking maximum efficiency of a expander-generator system of compressed air energy storage[J]. Energy Storage Science and Technology, 2017, 6(1):154-161.
[2] 罗宁, 何青, 刘文毅. 压缩空气储能系统储气装置研究现状与分析[J]. 储能科学与技术, 2018, 7(3):489-494. LUO Ning, HE Qing, LIU Wenyi. The development status and energy storage characteristic of gas storage device of compressed air energy storage system[J]. Energy Storage Science and Technology, 2018, 7(3):489-494.
[3] 高建强, 庄绪增, 敬赛. CAES电站储气室热力学特性的数值模拟研究[J]. 电力科学与工程, 2018, 34(12):67-72. GAO Jianqiang, ZUANG Xuzeng, JING Sai. Numerical simulation study on thermodynamic characteristics of gas storage chamber of CAES power station[J]. Electric Power Science and Engineering, 2018, 34(12):67-72.
[4] 张阳, 左志涛, 梁奇, 等. 离心压缩机可调叶片扩压器优化设计与调节分析[J]. 储能科学与技术, 2017, 6(6):1231-1238. ZHANG Yang, ZUO Zhitao, LIANG Qi, et al. Optimal design and adjustment analysis of an adjustable vane diffuser in a centrifugal compressor[J]. Energy Storage Science and Technology, 2017, 6(6):1231-1238.
[5] BARTON John, INFIELD David. Energy storage and its use with intermittent renewable energy[J]. IEEE Transactions on Energy Conversion, 2004, 19(2):441-448.
[6] 魏军英, 王鹏, 王吉岱, 等. 微型压缩空气储能系统工作特性研究[J]. 热力发电, 2019(3):28-34. WEI Junying, WANG Peng, WANG Jidai, et al. Working characteristics of micro compressed air energy storage system[J]. Thermal Power Generation, 2019(3):28-34.
[7] 陈海生, 刘金超, 郭欢, 等. 压缩空气储能技术原理[J]. 储能科学与技术, 2013, 2(2):146-151. CHEN Haisheng, LIU Jinchao, GUO Huan, et al. Technical principle of compressed air energy storage system[J]. Energy Storage Science and Technology, 2013, 2(2):146-151.
[8] 薛皓白, 张新敬, 陈海生, 等. 微型压缩空气储能系统释能过程分析[J]. 工程热物理学报, 2014, 35(10):1923-1929. XUE Haobai, ZHANG Xinjing, CHEN Haisheng, et al. Analysis of energy release process of micro-compressed air energy storage systems[J]. Journal of Engineering Thermophysics, 2014, 35(10):1923-1929.
[9] CHANG Jenchieh, CHANG Chaowei, HUNG Tzuchen, et al. Experimental study and CFD approach for scroll type expander used in low-temperature organic Rankine cycle[J]. Applied Thermal Engineering, 2014, 73(2):1444-1452.
[10] MORINI Mirko, PAVAN Claudio, PINELLI Michile, et al. Analysis of a scroll machine for micro ORC applications by means of a RE/CFD methodology[J]. Applied Thermal Engineering, 2015(80):132-140.
[11] SONG Panpan, WEI Mingshan, LIU Zhen, et al. Effects of suction port arrangements on a scroll expander for a small scale ORC system based on CFD approach[J]. Applied Energy, 2015(150):274-285.
[12] SONG Panpan, WEI Mingshan, ZHANG Yangjun, et al. The impact of a bilateral symmetric discharge structure on the performance of a scroll expander for ORC power generation system[J]. Energy, 2018(158):458-470.
[13] LIU Zhen, WEI Mingshan, SONG Panpan, et al. The fluid-thermalsolid coupling analysis of a scroll expander used in an ORC waste heat recovery system[J]. Applied Thermal Engineering, 2018(138):72-78.
[14] 刘祯, 吴华伟, 张琎, 等. 压缩空气储能用涡旋膨胀机非稳态流动特性分析[J]. 储能科学与技术, 2019, 8(2):357-364. LIU Zhen, WU Huawei, ZHANG Jin, KUANG Yong. Numerical investigations on unsteady flow of a scroll expander for compressed air energy storage[J]. Energy Storage Science and Technology, 2019, 8(2):357-364.
[15] DECLAY Sebastien, QUOILIN Sylvain, GUILLAUME Ludovic, et al. Experimental study on an open-drive scroll expander integrated into an ORC (Organic Rankine Cycle) system with R245fa as working fluid[J]. Energy, 2013, 55:173-183.
[16] LEMORT Vincent, DECLAY Sebastien, QUOILIN Sylvain. Experimental characterization of a hermetic scroll expander for use in a micro-scale Rankine cycle[J]. Proceedings of the Institution of Mechanical Engineers, Part A:Journal of Power and Energy, 2012, 226(1):126-136.