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作者简介:

刘纳(1985-),女,副教授,博士,研究方向为微尺度传热传质及液化天然气技术。E-mail:liuna86@126.com。

中图分类号:TK124

文献标识码:A

文章编号:1673-5005(2020)02-0136-08d

DOI:10.3969/j.issn.1673-5005.2020.02.017

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目录contents

    摘要

    研究 R22 和 R1234ze(E)在胀管前、后外径分别为 5.10 和 5. 26 mm 微肋管内的截面尺寸变化、凝结换热和摩擦压降特性。 分析质量流速、干度及胀管对凝结换热系数和摩擦压力梯度的影响。 采用关联式对试验结果进行预测,并对关联式的预测性能进行分析。 结果表明:胀管后微肋管的结构会发生一定程度的变形;凝结换热系数和摩擦压力梯度均随质量流速和干度增大而增大;质量流速为 100 kg / (m 2·s)时,胀管会削弱微肋管的凝结换热性能; 质量流速为 200 和 300 kg / (m 2·s)时,胀管对换热系数的影响不明显;而质量流速为 100 ~ 300 kg / (m 2·s)时,胀管对摩擦压力梯度的影响不显著。

    Abstract

    The measured cross section variation, condensation heat transfer and friction pressure drop were studied during the condensation of R22 and R1234ze(E) in pristine (5. 10 mm outer diameter(OD)) and expanded (5- 26 mm OD) micro-fin tubes. The effects of mass flux, vapor quality and tube expansion on the condensation heat transfer coefficients and friction pressure gradients for R22 and R1234ze(E) were analyzed. Correlations were used to predict the experimental results and predicted performances were assessed. The results show that the micro-fin tube deformed after expansion. The condensation heat transfer coefficients and friction pressure gradients both increase with the mass flux and vapor quality. The tube expan-sion degraded the condensation heat transfer performance in the micro-fin tube with the mass flux being 100 kg / (m 2 ·s). The effect of tube expansion on the heat transfer coefficient was not apparent with the mass fluxes being 200 kg / (m 2·s) and 300 kg / (m 2·s). However, for the mass fluxes being 100 ~ 300 kg / (m 2·s), the effect of tube expansion on the friction pressure gradient was not significant.

  • 微肋管于 20 世纪 70 年代由日本日立公司提出并制造,其后得到很大发展[1] ,目前在制冷系统翅片管式换热器中被广泛应用。为了提高换热器的传热效果,通常采用机械胀管方法扩张管径以减少肋片与管壁的接触热阻。胀管过程将直接改变微肋结构参数和管内换热面积,从而影响凝结换热和压降特性。有理论研究表明[2] ,由胀管导致的微肋管内凝结换热性能的衰退不可忽略。 Doretti 等[3] 、Cavallini、Lieben- berg 等[4-8]均对制冷剂在微肋管内的凝结换热流型开展了可视化研究。 试验研究方面,王智科等[9] 和 Lee 等[10]对外径大于 5 mm 微肋管内的凝结换热和压降特性开展了研究。而对于小直径微肋管内的凝结换热和压降特性有待深入研究[11] 。 理论研究方面,No- zu 等[12]基于流型观察结果建立了环状流型的凝结模型,对微肋管内的凝结换热进行了数值分析;Wang 等[13-14]对微肋管内凝结换热和压降的经验关联式和理论模型与试验结果进行了对比研究。 Mehendale [15] 对胀管过程中微肋管内的沸腾换热和压降开展了研究。 笔者研究 R22 和 R1234ze(E)在胀管前、后外径分别为 5. 10 和 5. 26 mm 微肋管内的截面尺寸变化、 凝结换热和摩擦压降特性。 分析质量流速、干度及胀管对凝结换热系数和摩擦压力梯度的影响。

  • 1 试验系统

  • 试验系统如图 1 所示,主要由制冷剂回路、冷却水回路和过冷水回路 3 部分组成。 制冷剂在回路中的流程:来自储液罐的制冷剂首先流经过滤器,在磁力驱动齿轮泵的驱动下,经由旁通回路调节系统流量后,进入质量流量计测量流量;从质量流量计流出的工质进入预热器,通过调节预热器的加热功率,将过冷状态的工质加热为一定干度的气液两相混合物;在试验段内被试验管外逆流流过的冷却水冷却发生凝结,之后进入过冷器,在过冷器内被逆流流过的过冷水进一步冷却为过冷状态,最后返回储液罐, 完成整个循环。

  • 试验段为一水平逆流套管式换热器,制冷剂在管内流动,冷却水在套管内逆流流动,结构示意图如图 2(单位:mm)所示。试验管为胀管前、后的微肋管,管长均为 535 mm,有效换热长度为 375 mm,套管是外径为 20 mm 的不锈钢圆管。 分别采用 4 根直径为 75 μm 的 T 型热电偶测量两个位置处的试验管外壁温,热电偶沿周向均匀布置;制冷剂和冷却水温度采用 Pt100 铂电阻温度传感器测量。 试验前采用 6020 系列高精度温度标定恒温水浴对铂电阻和热电偶进行标定。 制冷剂的压力采用 Trafag1498 型压力变送器测得,EJA110A 型差压变送器用于测量试验段进出口压差。 采用质量流量计测量制冷剂和冷却水的流量。

  • 图 1 试验系统

  • Fig. 1 Schematic diagram of experimental apparatus

  • 图 2 测试段示意图

  • Fig. 2 Schematic diagram of test section

  • 微肋管经线切割后,采用扫描电镜测量其截面尺寸,胀管前、后微肋管的截面尺寸对比结果见表 1,可见胀管之后微肋管外径增大 3.1% 、齿顶角增大 97.5% 、 管横截面积增大 7. 9% , 而肋高减小 9.1% 、底厚减小 8.7% 、 换热面积强化比减小 12.8% 。 主要分析胀管之后微肋管结构参数变化导致的管内凝结换热系数和压降特性变化。

  • 表 1 胀管前、后微肋管结构参数对比

  • Table 1 Comparison of structural parameters of pristine and expanded micro-fin tubes

  • 2 数据处理及误差分析

  • 2.1 数据处理

  • 微肋管实际换热面积 A 与名义换热面积 Afr(基于肋根直径 dfr)之比采用 Webb 和 Kim [16]表达式计算:

  • A/Afr=1+2[sec(γ/2)-tan(γ/2)]e/pr
    (1)
  • 式中,γ 为齿顶角,(°);e 为肋高,m;pf 为与肋垂直的肋间距,m。

  • 试验段的换热量 Q 可通过冷却水侧的吸热量计算得

  • Q=cp,cmc(tout-tin)
    (2)
  • 式中,cp,c为冷却水的定压比热容,J/ (kg·K);mc 为冷却水质量流量,kg / s;t in和 t out 分别为冷却水在试验段的进、出口温度,℃ 。

  • 制冷剂在试验段的进口干度 xin

  • xin=UI-mr(h1-hin)mrhlr
    (3)
  • 式中,U 为预热器电压,V;I 为电流,A;mr 为制冷剂质量流量,kg / s;hl 为饱和液体比焓,J/ kg;hin为制冷剂在预热器进口处比焓,J/ kg;hlv为制冷剂的汽化潜热,J/ kg。

  • 制冷剂在试验段的干度变化量 Δx 为

  • Δx=Qmrhlv
    (4)
  • 制冷剂干度 xave 取试验段进出口干度的平均值:

  • xave=xin-Δx2
    (5)
  • 微肋管外壁温度为

  • tw,o=i=18tw,i/8
    (6)
  • 式中,t 为微肋管第 i 个外壁面温度,℃ 。

  • 微肋管内、外壁面温差 Δ 为

  • Δtw=Qln(do/dfr)2πλl
    (7)
  • 式中,λ为微肋管导热系数,W/ (m·K);l 为有效换热长度,m;do 和 dfr分别为微肋管外径和肋根直径, m。

  • 工质的凝结换热系数 h 为

  • h=QA[(ts,in+ts,out)/2-(tw,o+Δtw)]
    (8)
  • 式中,t s,in和 t s,out分别为工质在试验段进、出口的饱和温度,益 。

  • 试验段总压降 Δp 由摩擦压降 Δpf 和工质发生凝结时引起的减速压升 Δpm 组成,表示为

  • Δpt=Δpf+Δpm
    (9)
  • Δpm 可采用 Carey [17]推荐的模型计算,表示为

  • Δpm=G2{[x2ρvα+(1-x)2ρ1(1-α)]out-[x2ρvα+(1-x)2ρ1(1-α)]in}
    (10)
  • 式中,α为空隙率;G 为工质质量流速,m / s;ρv 和 ρl 分别为气、液相密度,kg / m 3

  • 文献中没有适用于微肋管空隙率的计算模型, 通常采用光滑管模型来计算。 Newell 等[18] 通过测量两个微肋管发现:微肋管的空隙率与光滑管的几乎相等。 本文中分别采用均相流模型、 Zivi 模型[19] 、Baroczy 模型[20]及 Smith 模型[21] 计算饱和温度为 40 ℃时 R22 和 R1234ze(E)的空隙率,见图 3。

  • 图 3 R22 和 R1234ze(E)空隙率的经验模型计算结果

  • Fig. 3 Empirical model calculation results for void fractions of R22 and R1234ze(E)

  • 均相流模型的计算结果小于其他 3 种分相流模型。 3 种分相流模型的计算结果相近,3 种模型计算R22 和 R1234ze(E)空隙率时的最大平均偏差分别为 4.1% 和 3.7% 。 空隙率的微小差别对 Δpm 计算结果的影响较小。 因此,采用其中一种分相流模型 (Zivi 模型[19] )计算工质的空隙率。

  • 摩擦压力梯度计算式为

  • (-dpdz)f=Δpfl
    (11)
  • 试验数据处理过程中工质的热物性采用 NIST (Version 9- 0)物性软件[22]计算得到。

  • 2.2 误差分析

  • 试验参数的测量误差采用 Kline 和 Mc-Clintock [23]推荐的均方误差法进行分析,最大误差结果如下:管径 ±0. 01 mm,管长 ±0. 5 mm,温度(热电偶) ±0. 1 K,温度(RTDs) ±0.1 K,电压 ±0.1 V,电流 ±0. 1 A,制冷剂质量流量 ±0.2% FS kg / h(量程为 0 ~ 100 kg / h),冷却水质量流量 ±0. 2% FS kg / h(量程为 0 ~ 30 kg / h),压力 ±0. 3% FS MPa (量程为 0 ~ 6 MPa),压差 ±0.075% FS kPa(量程为 0 ~ 10 kPa),换热量 ±3.6% W,平均干度±4. 2% ,凝结换热系数 ± 10. 3% W/ (m 2·K),压力梯度 ±3.8% Pa / m。

  • 3 试验结果及分析

  • 流动凝结换热试验之前,为验证试验台的可靠性,开展了 R1234ze(E)在胀管前微肋管内的单相流动和换热试验。 工质质量流量为 18. 23 ~ 36. 09 kg / h,进口温度为 40.3 ~ 40. 8 ℃ ;冷却水流量为 11.4 ~ 11. 6 kg / h,冷却水进口温度为 16.3 ℃ 。 制冷剂侧和冷却水侧的换热量偏差在±5% 内。 将 R1234ze (E)在胀管前微肋管内的单相换热系数与内径为 dfr光滑管内的换热系数以及 Ravigururajanh 和 Ber- gles [24]关联式的预测结果进行对比,结果如图 4 所示。 换热系数试验值随雷诺数增大而增大,变化趋势与关联式的预测结果一致,大于光滑管内换热系数的预测结果,略低于 Ravigururajanh 和 Bergles [24] 关联式的预测结果,平均绝对偏差为 9% 。 单相试验表明试验段热损失小、保温性能良好、试验系统具有可靠性。

  • 图 4 胀管前微肋管内的单相换热结果

  • Fig. 4 Single-phase heat transfer results in pristine micro-fin tube

  • 流动凝结换热试验中,工质质量流速为 100 ~ 300 kg / (m 2·s),饱和温度为 40℃ ,干度为 0 ~ 1, 冷却水进口温度为 20 ℃ ,冷却水流量保持不变。

  • 3.1 凝结换热

  • R22 和 R1234ze(E)在胀管前、后微肋管内的凝结换热系数随干度变化如图 5 所示。

  • 图 5 胀管前、后微肋管内的凝结换热试验结果

  • Fig. 5 Experimental results of condensation heat transfer in pristine and expanded micro-fin tubes

  • 由图 5 可见,工质在胀管前、后微肋管内的凝结换热系数均随质量流速和干度增大而增大;且质量流速越大,凝结换热系数随干度增大的趋势愈发明显。 这是因为制冷剂质量流速增加时,工质与管壁间的对流换热得到加强,因此凝结换热系数增大;由于凝结液的导热热阻是凝结换热的主要热阻,随着干度增大,液膜厚度越薄,热阻越小,故凝结换热系数越大。

  • 图 5 还给出质量流速分别为 100、200 和 300 kg / (m 2·s)(图中表示为 G100,G200,G300)时胀管对 R22 和 R1234ze(E)在微肋管内凝结换热系数的影响。 由图 5 可见,质量流速为 100 kg / ( m 2 ·s) 时,R22 和 R1234ze(E)在胀管前微肋管内的凝结换热系数高于胀管后的;质量流速为 200 kg / (m 2·s) 和 300 kg / (m 2·s) 时胀管的影响并不显著。 微肋通过增加微肋管的换热面积、促进液膜流动湍流以及凝结液膜的重新分布,从而强化管内的换热性能。 微肋管经过胀管之后,微肋会经历一定程度的变形, 即齿顶角增加、肋高和内表面换热面积减小(表 1), 从而降低了流体湍流和表面张力引起液膜重新分布,进而削弱管内的凝结换热性能。 低质量流速 (100 kg / (m 2·s))时分层流型占主导,微肋在低质量流速时强化换热的作用较显著。 因此,质量流速为 100 kg / (m 2 ·s)时,胀管削弱了 R22 和 R1234ze (E)在微肋管内的凝结换热性能。 随着质量流速增加,气相对液膜的剪切作用增强,相比之下胀管对微肋管内凝结换热性能的削弱作用不再凸显。

  • 胀管前、后微肋管内的换热系数试验结果与关联式[4,25-27]预测值对比如图 6 所示。 采用试验结果和预测结果的算术平均偏差 A 和均方根偏差 R 评价每个关联式的预测情况,算术平均偏差和均方根偏差定义为

  • A=1Napre-aexpaeqp
    (12)
  • R=1N(apee-aexpaαp)2
    (13)
  • 式中,a 为换热系数 h 或摩擦压力梯度( -dp / dz)f;N 为试验数据个数。

  • 关联式对换热系数的预测偏差见表 2。 Kedzierski 和 Goncalves [26]的关联式对换热系数试验结果的预测较好,对 R22 和 R1234ze(E) 试验结果预测的均方根偏差分别为 29. 8% 和 22. 8% 。 Yu 和 Koyama [25]关联式对 R22 和 R1234ze(E) 试验结果预测的算术平均偏差为 44. 9% 和 20.9% ,而 Caval- lini 等[4]关联式的预测算术平均偏差为 35. 2% 和 39.2% 。 虽然 Cavallini 等[27] 的关联式能够较好地预测换热系数试验结果随干度的变化趋势,但对 R22 和 R1234ze(E)换热系数的预测值比试验值分别偏低 51. 3% 和 69. 4% 。 根据 Cavallini 等[4] 的总结,之前所研究的微肋管的肋高为 0. 2 ~ 0.25 mm、 管外径一般大于 9. 5 mm。 而本文中所采用微肋管的肋高(0.11 mm)和管外径(5. 10 mm)与 Cavallini 等[27]的相比较小,导致预测偏差存在。

  • 图 6 换热系数试验结果与关联式预测结果对比

  • Fig. 6 Comparison of predicted and experimental heat transfer coefficients

  • 表 2 关联式对换热系数的预测偏差

  • Table 2 Performance of correlations for heat transfer coefficients %

  • 3.2 两相摩擦压降

  • 图 7 给出质量流速为 100 kg / (m 2 ·s) 时 R22 和 R1234ze(E)在胀管后微肋管内的压降组成。 由图 7 可见,试验测量的总压降、凝结相变导致的压降和摩擦压降均随干度增大而增大。 所有试验工况下R22 和 R1234ze(E)在微肋管内凝结相变导致的压降占总压降的比例仅为 12. 4% 和 14.1% 。

  • R22 和 R1234ze(E)在胀管前、后微肋管内的摩擦压力梯度随干度的变化如图 8 所示。 与凝结换热试验结果类似,R22 和 R1234ze(E)在胀管前、后微肋管内的两相摩擦压力梯度也随质量流速和干度的增大而增大。 干度一定时,质量流速越大,气液相速度越大,剪切力越大导致摩擦压降增大;两相摩擦压力梯度随干度的增大趋势越明显,表明剪切力的作用更强。 质量流速一定时,干度越大,气液相间的速度差越大,导致摩擦压力梯度越大。

  • 图 7 胀管后微肋管内压降组成

  • Fig. 7 Pressure drop components in expanded micro-fin tube

  • 图 8 同时示出质量流速为 100、200 和 300 kg / (m 2·s) 时胀管对工质在微肋管内的摩擦压降影响。 由图8 可见,质量流速为100 ~ 300 kg / (m 2·s) 时 R22 和 R1234ze(E) 在胀管前、后微肋管内的摩擦压力梯度差别不大,表明本研究工况下胀管导致的微肋管微肋结构参数变化并没有对两相摩擦压力梯度产生显著影响。

  • 图 8 胀管前、后微肋管内的摩擦压力梯度试验结果

  • Fig. 8 Experimental results of friction pressure gradients in pristine and expanded micro-fin tubes

  • 胀管前、后微肋管内的摩擦压力梯度试验结果与关联式 ( Haraguchi 等[28] 、 Kedzierski 和 Goncla-ves [26] 、Choi 等[29] 、Goto 等[30] )预测结果对比如图 9 所示。 关联式对摩擦压力梯度预测见表 3。

  • 图 9 摩擦压力梯度试验结果与关联式预测结果对比

  • Fig. 9 Comparison of predicted and experimental friction pressure gradients

  • 由图 9 和表 3 的预测情况可见, Haraguchi 等[28] 、Kedzierski 和 Gonclaves [26] 、 Choi 等[29] 以及 Goto 等(Φv) [30] 4 个关联式均能够比较准确地预测本文的摩擦压力梯度试验结果随干度的变化趋势, 预测值与试验结果的算术平均偏差和均方根偏差均小于 21. 1% ,表明 4 个关联式均能够很好地预测本文中的摩擦压降试验结果。

  • 表 3 关联式对摩擦压力梯度预测

  • Table 3 Performance of correlations for friction pressure gradients %

  • 4 结论

  • (1)胀管后微肋管结构参数发生了一定程度的变形,即胀管之后微肋管外径增大 3. 1% 、齿顶角增大 97. 5% 、 管横截面积增大 7. 9% , 而肋高减小9. 1% 、底厚减小 8. 7% 、 换热面积强化比减小 12. 8% 。

  • (2)工质在胀管前、后微肋管内的凝结换热系数均随质量流速和干度的增大而增大;且质量流速越大,凝结换热系数随干度增大的趋势愈明显。 质量流速为 100 kg / (m 2 ·s) 时,胀管降低了 R22 和 R1234ze(E)在微肋管内的凝结换热性能;而质量流速为200 和 300 kg / (m 2 ·s) 时胀管对凝结换热系数的影响不显著。 Kedzierski 和 Goncalve 关联式对凝结换热系数试验结果的预测较好。

  • (3)工质在胀管前、后微肋管内的总压降、加速压降和摩擦压降均随干度增大而增大。 摩擦压力梯度随质量流速和干度增大而增大,且质量流速越大随干度增大的趋势越明显。 质量流速为 100 ~ 300 kg / (m 2·s)时胀管对摩擦压力梯度的影响并不显著。 Haraguchi 等、Kedzierski 和 Gonclaves、Choi 等以及 Goto 等 4 个关联式均能够很好地预测摩擦压力梯度试验结果。

  • 参考文献

    • [1] FUJIE K,ITOH M,INNAMI T,et al.Heat transfer pipe:US,4,044,797[P].1977-08-30.

    • [2] MEHENDALE S S.The impact of fin deformation on con-densation heat transfer coefficients in internally grooved tubes:ASME 2013 Heat Transfer Summer Conference collocated with the ASME 2013 7th International Confer-ence on Energy Sustainability and the ASME 2013 11th International Conference on Fuel Cell Science,Engineer-ing and Technology,July 14,2013 [ C].Minnessota:Minneapolis,2013.

    • [3] DORETTI L,ZILIO C,MANCIN S,et al.Condensation flow patterns inside plain and microfin tubes:a review [J].International Journal of Refrigeration,2013,36(2):567-587.

    • [4] CAVALLINI A,DEL COL D,MANCIN S,et al.Con-densation of pure and near-azeotropic refrigerants in mi-crofin tubes:a new computational procedure[J].Inter-national Journal of Refrigeration,2009,32(1):162-174.

    • [5] LIEBENBERG L,THOME J R,MEYER J P.Flow visu-alization and flow pattern identification with power spec-tral density distributions of pressure traces during refriger-ant condensation in smooth and microfin tubes[J].Jour-nal of Heat Transfer,2005,127(3):209-220.

    • [6] OLIVIER J A,LIEBENBERG L,THOME J R,et al.Heat transfer,pressure drop,and flow pattern recogni-tion during condensation inside smooth,helical micro-fin,and herringbone tubes[J].International Journal of Refrigeration,2007,30(4):609-623.

    • [7] CHEN Q,AMANO R,XIN M.Experimental study of flow patterns and regimes of condensation in horizontal three-dimensional micro-fin tubes [J].Heat and Mass Transfer,2006,43(2):201-206.

    • [8] MOHSENI S,AKHAVAN-BEHABADI M.Visual study of flow patterns during condensation inside a microfin tube with different tube inclinations [J].International Communications in Heat and Mass Transfer,2011,38(8):1156-1161.

    • [9] 王智科,孙显东,郭思璞,等.微小内螺纹管冷凝实验结果及关联式评价[J].浙江大学学报(工学版),2013,47(2):273-299.WANG Zhike,SUN Xiandong,GUO Sipu,et al.Experi-mental result of condensation in micro-fin tubes of differ-ent geometries[J].Journal of Zhejiang University(Engi-neering Science),2013,47(2):273-299.

    • [10] LEE E,KIM N,BYUN H.Condensation heat transfer and pressure drop in flattened microfin tubes having dif-ferent aspect ratios[J].International Journal of Refrige-ration,2014,38:236-249.

    • [11] WU Z,SUNDEN B,WANG L,et al.Convective con-densation inside horizontal smooth and microfin tubes [J].Journal of Heat Transfer,2014,136(5):051504.

    • [12] NOZU S,HONDA H.Condensation of refrigerants in horizontal,spirally grooved microfin tubes:numerical a-nalysis of heat transfer in the annular flow regime[J].Journal of Heat Transfer,2000,122(1):80-91.

    • [13] WANG H,ROSE J,HONDA H.Condensation of refrig-erants in horizontal microfin tubes:comparison of corre-lations for frictional pressure drop [J].International Journal of Refrigeration,2003,26(4):461-472.

    • [14] WANG H,HONDA H.Condensation of refrigerants in hor-izontal microfin tubes:comparison of prediction methods for heat transfer [J].International Journal of Refrigeration,2003,26(4):452-460.

    • [15] MEHENDALE S S.The impact of fin deformation on boiling heat transfer and pressure drop in internally grooved tubes:The 15th International Heat Transfer Conference,August 10-15,2014 [ C].Japan:Kyoto,2014.

    • [16] WEBB R L,KIM N H.Principles of enhanced heat transfer[M].New York:Taylor &Francis,2005:28-29.

    • [17] CAREY C J.Liquid-vapor phase change phenomena [M].New York:Hemisphere Publishing,1992:399-452.

    • [18] NEWELL T,SHAH R.An assessment of refrigerant heat transfer,pressure drop,and void fraction effects in microfin tubes [J].HVAC &R Research,2001,7(2):125-153.

    • [19] ZIVI S.Estimation of steady-state steam void-fraction by means of the principle of minimum entropy production [J].Journal of Heat Transfer,1964,86(2):247-251.

    • [20] BAROCZY C J.Systematic correlation for two-phase pressure drop [J].Chemical Engineering Progress,1966,62(64):232-249.

    • [21] SMITH S.Void fractions in two-phase flow:a correla-tion based upon an equal velocity head model[J].Pro-ceedings of the Institution of Mechanical Engineers,1969,184(1):647-664.

    • [22] LEMMON E W,HUBER M L,MCLINDEN M O.NIST reference fluid thermodynamic and transport properties— REFPROP [J].NIST Standard Reference Database,2002,23:7.

    • [23] KLINE S J,MCCLINTOCK F A.The description of un-certainties in single sample experiments[J].Mechanical Engineering,1953,75:3-9.

    • [24] RAIGURURAJAN T,BERGLES A.Development and verification of general correlations for pressure drop and heat transfer in single-phase turbulent flow in enhanced tubes[J].Experimental Thermal and Fluid Science,1996,13(1):55-70.

    • [25] YU J,KOYAMA S.Condensation heat transfer of pure refrigerants in microfin tubes[J].International Refrige-ration and Air Conditioning Conference,1998,431:325-330.

    • [26] KEDZIERSKI M A,GONCALVES J.Horizontal con-vective condensation of /html/zgsydxxb/20200217/alternative refrigerants within a micro-fin tube[J].Journal of Enhanced Heat Transfer,1999,6(2/3/4):161-178.

    • [27] CAVALLINI A,DEL COL D,DORETTI L,et al.A new computational procedure for heat transfer and pres-sure drop during refrigerant condensation inside en-hanced tubes[J].Journal of Enhanced Heat Transfer,1999,6(6):441-456.

    • [28] HARAGUCHI H,KOYAMA S,ESAKI J,et al.Con-densation heat transfer of refrigerants HCFC134a,HCFC123,and HCFC22 in a horizontal smooth tube and a horizontal micro-fin tube:Proceedings of 30th National Heat Transfer Symposium,August 6-8,1995[C].Port-land:Oregon,1995.

    • [29] CHOI J Y,KEDZIERSKI M A,KEDZIERSKI P A.Generalized pressure drop correlation for evaporation and condensation in smooth and micro-fin tubes [J].Proceedings of IIF-IIR Commission B,2001,1:9-16.

    • [30] GOTO M,INOUE N,ISHIVWATARI N.Condensation and evaporation heat transfer of R410A inside internally grooved horizontal tubes [J].International Journal of Refrigeration,2001,24(7):628-638.

  • 参考文献

    • [1] FUJIE K,ITOH M,INNAMI T,et al.Heat transfer pipe:US,4,044,797[P].1977-08-30.

    • [2] MEHENDALE S S.The impact of fin deformation on con-densation heat transfer coefficients in internally grooved tubes:ASME 2013 Heat Transfer Summer Conference collocated with the ASME 2013 7th International Confer-ence on Energy Sustainability and the ASME 2013 11th International Conference on Fuel Cell Science,Engineer-ing and Technology,July 14,2013 [ C].Minnessota:Minneapolis,2013.

    • [3] DORETTI L,ZILIO C,MANCIN S,et al.Condensation flow patterns inside plain and microfin tubes:a review [J].International Journal of Refrigeration,2013,36(2):567-587.

    • [4] CAVALLINI A,DEL COL D,MANCIN S,et al.Con-densation of pure and near-azeotropic refrigerants in mi-crofin tubes:a new computational procedure[J].Inter-national Journal of Refrigeration,2009,32(1):162-174.

    • [5] LIEBENBERG L,THOME J R,MEYER J P.Flow visu-alization and flow pattern identification with power spec-tral density distributions of pressure traces during refriger-ant condensation in smooth and microfin tubes[J].Jour-nal of Heat Transfer,2005,127(3):209-220.

    • [6] OLIVIER J A,LIEBENBERG L,THOME J R,et al.Heat transfer,pressure drop,and flow pattern recogni-tion during condensation inside smooth,helical micro-fin,and herringbone tubes[J].International Journal of Refrigeration,2007,30(4):609-623.

    • [7] CHEN Q,AMANO R,XIN M.Experimental study of flow patterns and regimes of condensation in horizontal three-dimensional micro-fin tubes [J].Heat and Mass Transfer,2006,43(2):201-206.

    • [8] MOHSENI S,AKHAVAN-BEHABADI M.Visual study of flow patterns during condensation inside a microfin tube with different tube inclinations [J].International Communications in Heat and Mass Transfer,2011,38(8):1156-1161.

    • [9] 王智科,孙显东,郭思璞,等.微小内螺纹管冷凝实验结果及关联式评价[J].浙江大学学报(工学版),2013,47(2):273-299.WANG Zhike,SUN Xiandong,GUO Sipu,et al.Experi-mental result of condensation in micro-fin tubes of differ-ent geometries[J].Journal of Zhejiang University(Engi-neering Science),2013,47(2):273-299.

    • [10] LEE E,KIM N,BYUN H.Condensation heat transfer and pressure drop in flattened microfin tubes having dif-ferent aspect ratios[J].International Journal of Refrige-ration,2014,38:236-249.

    • [11] WU Z,SUNDEN B,WANG L,et al.Convective con-densation inside horizontal smooth and microfin tubes [J].Journal of Heat Transfer,2014,136(5):051504.

    • [12] NOZU S,HONDA H.Condensation of refrigerants in horizontal,spirally grooved microfin tubes:numerical a-nalysis of heat transfer in the annular flow regime[J].Journal of Heat Transfer,2000,122(1):80-91.

    • [13] WANG H,ROSE J,HONDA H.Condensation of refrig-erants in horizontal microfin tubes:comparison of corre-lations for frictional pressure drop [J].International Journal of Refrigeration,2003,26(4):461-472.

    • [14] WANG H,HONDA H.Condensation of refrigerants in hor-izontal microfin tubes:comparison of prediction methods for heat transfer [J].International Journal of Refrigeration,2003,26(4):452-460.

    • [15] MEHENDALE S S.The impact of fin deformation on boiling heat transfer and pressure drop in internally grooved tubes:The 15th International Heat Transfer Conference,August 10-15,2014 [ C].Japan:Kyoto,2014.

    • [16] WEBB R L,KIM N H.Principles of enhanced heat transfer[M].New York:Taylor &Francis,2005:28-29.

    • [17] CAREY C J.Liquid-vapor phase change phenomena [M].New York:Hemisphere Publishing,1992:399-452.

    • [18] NEWELL T,SHAH R.An assessment of refrigerant heat transfer,pressure drop,and void fraction effects in microfin tubes [J].HVAC &R Research,2001,7(2):125-153.

    • [19] ZIVI S.Estimation of steady-state steam void-fraction by means of the principle of minimum entropy production [J].Journal of Heat Transfer,1964,86(2):247-251.

    • [20] BAROCZY C J.Systematic correlation for two-phase pressure drop [J].Chemical Engineering Progress,1966,62(64):232-249.

    • [21] SMITH S.Void fractions in two-phase flow:a correla-tion based upon an equal velocity head model[J].Pro-ceedings of the Institution of Mechanical Engineers,1969,184(1):647-664.

    • [22] LEMMON E W,HUBER M L,MCLINDEN M O.NIST reference fluid thermodynamic and transport properties— REFPROP [J].NIST Standard Reference Database,2002,23:7.

    • [23] KLINE S J,MCCLINTOCK F A.The description of un-certainties in single sample experiments[J].Mechanical Engineering,1953,75:3-9.

    • [24] RAIGURURAJAN T,BERGLES A.Development and verification of general correlations for pressure drop and heat transfer in single-phase turbulent flow in enhanced tubes[J].Experimental Thermal and Fluid Science,1996,13(1):55-70.

    • [25] YU J,KOYAMA S.Condensation heat transfer of pure refrigerants in microfin tubes[J].International Refrige-ration and Air Conditioning Conference,1998,431:325-330.

    • [26] KEDZIERSKI M A,GONCALVES J.Horizontal con-vective condensation of /html/zgsydxxb/20200217/alternative refrigerants within a micro-fin tube[J].Journal of Enhanced Heat Transfer,1999,6(2/3/4):161-178.

    • [27] CAVALLINI A,DEL COL D,DORETTI L,et al.A new computational procedure for heat transfer and pres-sure drop during refrigerant condensation inside en-hanced tubes[J].Journal of Enhanced Heat Transfer,1999,6(6):441-456.

    • [28] HARAGUCHI H,KOYAMA S,ESAKI J,et al.Con-densation heat transfer of refrigerants HCFC134a,HCFC123,and HCFC22 in a horizontal smooth tube and a horizontal micro-fin tube:Proceedings of 30th National Heat Transfer Symposium,August 6-8,1995[C].Port-land:Oregon,1995.

    • [29] CHOI J Y,KEDZIERSKI M A,KEDZIERSKI P A.Generalized pressure drop correlation for evaporation and condensation in smooth and micro-fin tubes [J].Proceedings of IIF-IIR Commission B,2001,1:9-16.

    • [30] GOTO M,INOUE N,ISHIVWATARI N.Condensation and evaporation heat transfer of R410A inside internally grooved horizontal tubes [J].International Journal of Refrigeration,2001,24(7):628-638.

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