PR方程推算氮气/灭火剂蒸气等熵指数

陈梦东; 余建祖; 施尚; 谢永奇

doi:10.13224/j.cnki.jasp.2017.10.010

PR方程推算氮气/灭火剂蒸气等熵指数

doi: 10.13224/j.cnki.jasp.2017.10.010

1.
北京航空航天大学航空科学与工程学院,北京 100191
2.
北京航空航天大学航空科学与工程学院,北京 100191；2.北京航空航天大学航空科学与工程学院人机工效与环境控制重点学科实验室,北京 100191

计量
- 文章访问数: 725
- HTML浏览量: 3
- PDF量: 519
- 被引次数: 0
出版历程
- 收稿日期: 2016-03-29
- 刊出日期: 2017-10-28

Estimating isentropic exponent for nitrogen and fire extinguishing agent vapor using PR equation

摘要

摘要: 氮气(N2)/灭火剂蒸气组成的混合气体的容积等熵指数和温度等熵指数随充填压力和温度的变化关系是影响机载灭火系统灭火剂释放过程的重要因素。基于PR(PengRobinson)方程和范德瓦尔混合规则,编制了N2/灭火剂混合气体的容积等熵指数和温度等熵指数的计算程序,计算了三组混合气体N2/HFC227ea、N2/CF3I和N2/CF3Br充填压力分别为42MPa和25MPa,初始温度为293K时等熵指数随温度的变化曲线。结果表明:它们的容积等熵指数和温度等熵指数随着温度的升高而逐渐下降,呈近似线性关系。在相同温度下,充填压力为42MPa时的三组混合物的容积等熵指数和温度等熵指数均高于充填压力25MPa时的结果。在相同的充填压力和温度下,N2/CF3I的等熵指数最大,其次为N2/HFC227ea和N2/CF3Br的最小。
- 灭火系统 /
- PR方程 /
- 等熵指数 /
- 灭火剂 /
- 气液平衡
Abstract: The variation of volumetric isentropic exponent and temperature isentropic exponent of the gas mixture of nitrogen (N2) and fire extinguishing agent vapor with pressurized pressure and temperature are a key influential factor to the fire extinguishing agent discharge progress for the aircraft fire extinguishing system. Based on the PR(PengRobinson) equation associated with the classical van der Waals mixing rule, a program was developed to estimate volumetric isentropic exponent and temperature isentropic exponent for the mixture of N2 and fire extinguishing agent vapor. The curves of volumetric isentropic exponent and temperature isentropic exponent varying with temperature were calculated with the pressurized pressure of 42MPa and 25MPa and initial temperature of 293K for the binary system of N2/HFC227ea, N2/CF3I and N2/CF3Br. The results showed that volumetric isentropic exponent and temperature isentropic exponent decreased as temperature increased and the relation was nearly linear. The volumetric isentropic exponent and temperature isentropic exponent of all the three binary systems had a higher value with pressurized pressure of 42MPa than with 25MPa at the same temperature. When pressurized to an equal pressure at same temperature, isentropic exponent of N2/CF3I had a largest value followed by the results of N2/HFC227ea and N2/CF3Br.
- fire extinguishing system /
- PR equation /
- isentropic exponent /
- fire extinguishing agent /
- vapour-liquid equilibrium

HTML

参考文献(18)

[1]	GANN R G.Nextgeneration fire suppression technology program［J］.Fire Technology,1998,34(4):363-371.
[2]	GANN R G.FY2002 annual report:next generation fire suppression technology program (NGP)［R］.Washington:National Institute of Standards and Technology,2002.
[3]	GANN R G.Advanced technology for fire suppression in aircraft:the final report［R］.Washington:National Institute of Standards and Technology,2007.
[4]	BORGHHETTI L,CHAER S,FERGUSON D,et al.Options for aircraft engine fire protection［R］.Chicago,US:Boeing Commericial Airplane Group,2000.
[5]	YANG J C,CLEARY T G,VZQUEZ I,et al.Optimization of system discharge［R］.Washington:US Department of Commerce,NIST-SP-890,1995.
[6]	刘晖.实际气体温度绝热指数和容积绝热指数的计算［J］.石油化工高等学校学报,2000,13(4):42-45. LIU Hui.Calculation of the isentropic temperature change exponent and isentropic volume change exponent of real gases［J］.Journal of Petrochemical Universities,2000,13(4):42-45.(in Chinese)
[7]	周训飞,赵小明,郭智恺,等.利用 PR 方程推算替代制冷剂的绝热指数［J］.工程热物理学报,2012,33(4):548-552. ZHOU Xunfei,ZHAO Xiaoming,GUO Zhikai,et al.Calculation of adiabatic exponent using PR equation［J］.Journal of Engineering Thermophysics,2012,33(4):548-552.(in Chinese)
[8]	牛雪民,谢永奇,余建祖.无通风直升机动力舱火灾温度场数值模拟［J］.航空动力学报,2011,26(8):1761-1767. NIU Xuemin,XIE Yongqi,YU Jianzu.Simulation study on helicopter nacelle ventilation cooling system［J］.Journal of Aerospace Power,2011,26(8):1761-1767.(in Chinese)
[9]	陈梦东,谢永奇,郭祥祥,等.基于PR方程和WS混合规则预测灭火瓶氮气充填量［J］.北京航空航天大学学报,2016,42(10):2014-2020. CHEN Mengdong,XIE Yongqi,GUO Xiangxiang,et al.Calculating the filling mass of nitrogen in the fire agent bottle based on PR equation of state with wongsandler mixing rule［J］.Journal of Beijing University of Aeronautics and Astronautics,2016,42(10):2014-2020.(in Chinese)
[10]	陈梦东,余建祖,谢永奇.基于VTPR方程计算N2/CF3I充填特性［J］.航空学报,2016,37(12):3706-3712. CHEN Mengdong,YU Jianzu,XIE Yongqi.Calculating the filling properties for N2/CF3I based on volume translation PengRobinson equation of state［J］.Acta Aeronautica et Astronautica Sinica,2016,37(12):3706-3712.（in Chinese）
[11]	LIN Hong,DUAN Yuanyuan.Empirical correction to the PengRobinson equation of state for the saturated region［J］.Fluid Phase Equilibria,2005,233(2):194-203.
[12]	苏长荪,谭连城,刘桂玉.高等工程热力学［M］.北京:高等教育出版社,1987.
[13]	LEMMON E W,MCLINDEN M O,HUBER M L.NIST reference fluid thermodynamic and transport properties (REFPROP) ［M］.8th ed.Gaithersburg,US:National Institute of Standards and Technology,2007.
[14]	LIM J S,KIM J.Vapor liquid equilibria of the binary systems nitrogen+ bromotrifluoromethane,+bromochlorodifluoromethane,+1,1,1,2,3,3,3heptafluoropropane,and + trifluoroiodomethane from 293.2 to 313.2K and 30 to 100 bar［J］.Journal of Chemical and Engineering Data,1997,42(1):112-115.
[15]	YANG J C,CLEARY T G,VZQUEZ I,et al.Measured and predicted thermodynamic properties of selected halon alternative/nitrogen mixtures［J］.International Journal of Refrigeration,1997,20(2):96-105.
[16]	SPAN R,LEMMON E W,JACOBSEN R T,et al.A reference equation of state for the thermodynamic properties of nitrogen for temperatures from 63151 to 1000K and pressures to 2200MPa［J］.Journal of Physical and Chemical Reference Data,2000,29(6):1361-1433.
[17]	杨亚晶,何茂刚,张颖.混合制冷剂比定压热容的理论推算［J］.化学工程,2007,35(10):42-45. YANG Yajing,HE Maogang,ZHANG Ying.Estimation of isobaric specific heat for mixing refrigerant［J］.Chemical Engineering,2007,35(10):42-45.(in Chinese)
[18]	段远源,徐建锋.适用于整个区域的HFC227ea状态方程［J］.工程热物理学报,2003,24(1):22-24. DUAN Yuanyuan,XU Jianfeng.A new equation of state for HFC227ea over entire region［J］.Journal of Engineering Thermophysics,2003,24(1):22-24.(in Chinese)