【正文】 shaped fin tube is shown in Figure 3. The ribshaped fin tube is formed from a bare tube by a coldcutting extrusion process with no metal being removed. The outer diameter over fins is larger than that of the staring bare tube size. The lowfin tube is formed from bare tube by a coldrolling extrusion process, and the tube retains almost the same outer diameter over fins as the starting bare tube size. Both the ribshaped fin and lowfin tubes are manufactured from bare copper tube. Table 1. The Geometrical Parameters of Tested Tubes 武漢工程大學(xué)郵電與信息工 程學(xué)院畢業(yè)設(shè)計(jì) 5 contents starting bare tube mm dofmm dimm drmm hfmm pmm smm tmm ribshaped fin tube Φ??? 10 lowfin tube Φ??? Figure 3. Photography of ribshaped fin tube. ? 3 Data Reduction and Uncertainty To pare the characteristics of heat transfer of heat exchangers bined with different enhanced tubes, the shellside heat transfer coefficients αo must be determined. The energy balance between the oil and cooling water sides was found to be within % for all runs. That is where The thermodynamic and transport properties of oil and water are calculated according to the averages of the test section inlet and outlet temperatures. The overall heat transfer coefficient of heat exchanger is puted using the mean temperature difference (MTD) method: where Ao is heat transfer area based on outside nominal area of tubes, F is correction factor based on one shell pass and two tube passes heat exchanger design,(9) and LMTD is the log mean temperature difference. The overall heat transfer coefficient of heat exchanger based on the outside nominal surface area of test tubes is where Ai is inside surface area of test tubes, Rwall is the thermal resistance of the tube wall. The tube side heat transfer coefficients αi were obtained by Wilson plot technique.(10) 武漢工程大學(xué)郵電與信息工 程學(xué)院畢業(yè)設(shè)計(jì) 6 It is found that the constants in correlation 13 and 14 are slightly larger than the wellknown constant of the Dittus?Boelter correlation remended to calculate heat transfer coefficient in smooth tube for turbulent flow. The reason is that microribs are formed in the inner surface of test tubes when the fin tubes are manufactured by the extrusion process, and heat transfer coefficients of the tube side are improved. The shellside Nusselt number can be obtained depending on the shellside heat transfer coefficient from the following equation: dr is the outer diameter of the fin tube at the fins root, λoil is the oil thermal conductivity. The shellside Reynolds number and Euler number are defined as follows: where umax is the maximum velocity of oil through the tube bundle. To find it, the minimum cross section area Amin must be evaluated. This is given as where Di is the shell inside diameter, dc is the central tube outside diameter, S is the baffle spacing, and PT is tube pitch. An uncertainty analysis of the experimental results has been carried out. Experimental uncertainties in the shellside Nusselt and Euler number were estimated by the procedure described Kline and McClitock.(11) The highest uncertainties of Nu and Eu are 177。Pr. Compared the experimental data in Figure 4 with Figure 5, it can be found that the increase in heat transfer is significantly greater than that of the increase in pressure drop at constant Re for lowfin tubes, Nu = (Res) Δav = standard deviation, Δav = ((∑1n ((Zi ? Zic)/Zi) 2)/n)1/2 Subscripts ave = average c = central tube i = inside in = inlet max = maximum min = minimum o = outside out = outlet w = water References This article references 12 other publications. , P.。 Oonnell, Jr., J.。 DeWitt, D. P. Fundamentals of Heat and Mass Transfer。2020 年美國(guó)化學(xué)學(xué)會(huì) 南中國(guó)科技大學(xué)。特別是，在傳統(tǒng)的管殼式換熱器的殼側(cè)流路是浪費(fèi)的壓力降，限制了最大熱效率，并鼓勵(lì)死點(diǎn)或回流區(qū)的，可能會(huì)發(fā)生結(jié)垢的。擋板誘導(dǎo)的流動(dòng)型態(tài)也引起了殼側(cè)傳熱顯著增加。到現(xiàn)在為止，很少有一個(gè)整體的螺旋折流板換熱器的研究工作（ 68）已公開發(fā)表的文獻(xiàn)，特別是強(qiáng)化傳熱。的折流板的間距和厚度分別為 72 和 毫米。 ℃。實(shí)驗(yàn)開始掃描每個(gè)數(shù)據(jù)點(diǎn)，而該系統(tǒng)達(dá)到一個(gè)穩(wěn)定的狀態(tài)。低 武漢工程大學(xué)郵電與信息工 程學(xué)院畢業(yè)設(shè)計(jì) 14 翅片管是由冷軋的擠壓過程中形成從裸管，管保留至散熱片作為起始的裸管的尺寸幾乎相同的外徑。熱交換器的總傳熱系數(shù)的計(jì)算的平均溫差（ MTD）的方法：其中敖是根據(jù)管外面的公稱截面積的 傳熱面積， F 是修正因子的基礎(chǔ)上的一個(gè)殼程和管程換熱器的設(shè)計(jì)，（ 9）和 LMTD 是對(duì)數(shù)平均溫度差。被給定為其中 Di 為外殼內(nèi)徑， dc 是中心管外徑， S 是折流板的間距，和 PT 是管心距?？梢杂^察到從圖 4 中，如新增加回復(fù)怒江 RE?PR 的變化。 以下相關(guān)建議為女和 Eu（文獻(xiàn)（ 12）中所描述的），在管殼式換熱器的殼側(cè)與殼程和兩個(gè)管的形式，通過 實(shí)驗(yàn)結(jié)果的基礎(chǔ)上，建議值 a 和 m列于表 2。方程 19 和 20 的標(biāo)準(zhǔn)偏差 Δ AV％ 5 結(jié)論 本文介紹了試點(diǎn)工作開展比較殼側(cè)努塞爾特的螺旋隔板帶肋形翅片管換熱器和Euler 數(shù)的低肋管油冷卻采用水作為冷 卻劑。 PR） 。 K / W） Re 為雷諾數(shù) S =鰭整個(gè)圓周空間（米） S =擋板間距（ m） T =溫度（ K） T =翅片厚度（米） U =油速度（米 /秒） U =總傳熱系數(shù)（ W /（㎡ Nemcansky， 。重要國(guó)際會(huì)議為過程工業(yè)的緊湊式換熱器 。 1993，36， 565 ， SJ。英。侯賽尼 J. 2020， 15， 1555 ZG。 Nemcansky， J.。秒） ，Δ AVΔ AV=標(biāo)準(zhǔn)差 =（（Σ 1n（（字 ZIC） /字） 2） / N） 1/2 平均 =平均 武漢工程大學(xué)郵電與信息工 程學(xué)院畢業(yè)設(shè)計(jì) 17 C =中央管 I =內(nèi)部 =入口 MAX =最大 分鐘 =最低 O =外 =出口 W =水 武漢工程大學(xué)郵電與信息工 程學(xué)院畢業(yè)設(shè)計(jì) 18 參考文獻(xiàn) 本文引用其他 12 個(gè)出版物。這些相關(guān)性提供非常好的協(xié)議與肋形翅片和低翅片管的實(shí)驗(yàn)結(jié)果。 PR 值怒江和歐盟的螺旋隔板帶肋形翅片管換熱器的基礎(chǔ)上，不斷重新約 倍和 倍大的螺旋隔板低肋管熱交換器用的，分別熱傳遞的增加是顯著大于肋狀翅片管的壓降增加。 表 2 中。 PR 值。 PR 范圍，是大低肋管螺旋隔板換熱器的 倍。 ％和％，分別。其原因是，的 microribs 試管的內(nèi)表面上形成在翅片管制造的擠出過程中，管側(cè)的傳熱系數(shù)改善。攝影的肋狀翅片管。 測(cè)試管的參數(shù)示于表 1。 ％的范圍 0100 千帕的壓力傳感器測(cè)得的壓力的壓力計(jì)。被泵入熱交換器加