Please wait a minute...
JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE)  2018, Vol. 52 Issue (5): 966-970    DOI: 10.3785/j.issn.1008-973X.2018.05.017
Mechanical and Energy Engineering     
Experimental study and improvements of capacitance-type liquid level meter for cryogenic slurries
LI Yi-jian, WU Shu-qin, JIN Tao
Institute of Refrigeration and Cryogenics, Key Laboratory of Refrigeration and Cryogenic Technology of Zhejiang Province, Zhejiang University, Hangzhou 310027, China
Download:   PDF(1969KB) HTML
Export: BibTeX | EndNote (RIS)      

Abstract  

The capacitance method for liquid level measurements of slush nitrogen was experimentally analyzed, in order to solve the problem for poor measurement stability of capacitance-type sensors. An earth grounded coaxial tube was adopted to shield the double coaxial tube electrodes for protecting from the electromagnetic interference and mechanical vibration in order to improve the accuracy and stability of the capacitance-type liquid level meter. The calibration test results show that the liquid level meter has good linearity, high sensitivity and accuracy with the average sensitivity of 46.76 pF/m and the measurement error of ±0.23%. The liquid level meter was used to measure the liquid level and flow velocity of slush nitrogen. Results show that the capacitance-type liquid level meter has high stability. The method for flow velocity measurements through liquid level change is reliable.



Received: 25 March 2017      Published: 07 November 2018
CLC:  TB51  
Cite this article:

LI Yi-jian, WU Shu-qin, JIN Tao. Experimental study and improvements of capacitance-type liquid level meter for cryogenic slurries. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2018, 52(5): 966-970.

URL:

http://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2018.05.017     OR     http://www.zjujournals.com/eng/Y2018/V52/I5/966


低温浆体电容式液位计的优化及实验

针对电容传感器测量稳定性差的问题,采用电容法对氮浆液位的测量开展实验及优化研究.为了改善电容式液位计的稳定性和精度,采用双层同轴管结构作为电极,在电极外增加全屏蔽同轴管并接地,降低周围环境电磁及机械干扰.标定实验结果表明,液位计具有较好的线性度、灵敏度和精度,平均灵敏度为46.76 pF/m,液位测量相对误差在±0.23%以内.将标定的液位计运用于氮浆液位及流速的测量,测试结果显示,优化的电容式液位计运行稳定,利用液位变化来估算流速的方法较可靠.

[1] CARNEY R R. "Slush hydrogen" production and handling as a fuel for space projects[M].:Springer US, 1964, 529-536.
[2] REYNIER P, BUGEL M, LECOîNTRE J. Review of the modelling of slush hydrogen flows[J]. Journal of Computational Multiphase Flows, 2011, 3(3):123-146.
[3] JIN T, LI Y J, LIANG Z B, et al. Numerical prediction of flow characteristics of slush hydrogen in a horizontal pipe[J]. International Journal of Hydrogen Energy, 2017,42(6):3778-3779.
[4] JIN Tao, LI Yi-jian, WU Shu-qin, et al. Numerical modeling for the flow and heat transfer of slush nitrogen in a horizontal pipe based on population balance equations[J]. Applied Thermal Engineering, 2017,123:301-309.
[5] OHIRA K, ISHIMOTO J, NOZAWA M, et al. Heat transfer characteristics of slush nitrogen in turbulent pipe flows[C]//Advances in Cryogenic Engineering. Seoul, Korea:AIP Publishing, 2008, 985:1141-1148.
[6] PARK Y M. Literature research on the production, loading, flow, and heat transfer of slush hydrogen[J]. International Journal of Hydrogen Energy, 2010, 35(23):12993-13003.
[7] YOON T K, LEE D R, CHA S K, et al. Survival rate of human oocytes and pregnancy outcome after vitrification using slush nitrogen in assisted reproductive technologies[J]. Fertility & Sterility, 2007, 88(4):952-956.
[8] OHIRA K, MATSUO S, FURUMOTO H. An experimental investigation of production and density measurement of slush hydrogen[J]. Cryogenics, 1994, 34(1):397-400.
[9] OHIRA K, NAKAGOMI K, TAKAHASHI N. Pressure-drop reduction and heat-transfer deterioration of slush nitrogen in horizontal pipe flow[J]. Cryogenics, 2011, 51(10):563-574.
[10] BAKER M J, DENTON T T, HERR C. An explanation for why it is difficult to form slush nitrogen from liquid nitrogen used previously for this purpose[J]. Cryobiology, 2013, 66(1):43-46.
[11] OHIRA K. Study of nucleate boiling heat transfer to slush hydrogen and slush nitrogen[J]. Heat Transfer-Asian Research, 2003, 32(1):13-28.
[12] ZHANG P, JIANG Y Y. Forced convective heat transfer of slush nitrogen in a horizontal pipe[J]. International Journal of Heat & Mass Transfer, 2014, 71(1):158-171.
[13] JIANG Y Y, ZHANG P. Density determination of slush nitrogen by the improved capacitance-type densimeter[J]. Experimental Thermal & Fluid Science, 2011, 35(2):328-337.
[14] 曹建,安刚,马晨辉,等.低温液位计[J].导弹与航天运载技术,2008,(6):52-54. CAO Jian, AN Gang, MA Chen-hui, et al. Low temperature liquid level indicator[J]. Missiles and Space Vehicles, 2008, (6):52-54.
[15] 马登奎,毕延芳,冯汉升,等.浮力式低温液位计的设计原理及运行工况分析[J].低温与超导,2009,37(7):16-19. MA Deng-kui, BI Yan-fang, FENG Han-sheng, et al. Design principles and operating conditions analysis of buoyancy cryogenic liquid level meter[J]. Cryogenics and Superconductivity, 2009, 37(7):16-19.
[16] PARK H C, JEONG H J, LEE C Y, et al. Liquid nitrogen level meter for high-temperature superconductor (HTS)[J]. Journal of Central South University of Technology, 2012, 19(11):3100-3104.
[17] KNIGHT B L, TIMMERHAUS K D, FLYNN T M. A superconducting liquid-Level sensor for slush hydrogen use[M].:Springer, Boston, MA, 1966, 218-222.
[18] LERSCH D, PASCOVICI G, BIRKENBACH B, et al. The liquid nitrogen fill level meter for the AGATA triple cluster detector[J]. Nuclear Instruments & Methods in Physics Research, 2011, 640(1):133-138.
[19] LEE C K, HWANG G W, JEONG S K. Development of cryogenic liquid-vapor separator and liquid-level meter operating under high pressure condition[J]. Progress in Superconductivity & Cryogenics, 2011, 13(1):51-55.
[20] 江芋叶,张鹏.氮浆电容式密度计及液位计的实验研究[J].低温与超导,2010,38(5):19-23. JIANG Yu-ye, ZHANG Peng. Study on the capacitance-type densimeter and liquid level meter for slush nitrogen[J]. Cryogenics and Superconductivity, 2010, 38(5):19-23.
[21] STEWART J W. Dielectric polarizability of fluid para-hydrogen[J]. Journal of Chemical Physics, 1964, 40(11):3297-3306.

[1] LI Ming, FENG Ye, TANG Ke, JIN Tao. Influence of Gedeon streaming on performance of four-stage travelling-wave thermoacoustic engine[J]. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2017, 51(8): 1633-1639.