【正文】 enumber, and under the same shell side velocity and with different tube velocities for FBSTHX the heat transfer and flow resistance characteristic in shell side are almost the same, which prove the good repetition of the 7 and 8 show the heat transfer and flow resistance characteristics for SBSTHX. The lines shown in these figures were fitted by the method of least squares,and the heat transfer correlation in the range of 4,000 B ReB 15,000 can be expressed as the correlation coefficient for above equation is r = .The flow resistance correlation in the ranger of 4,000 B ReB 15,000 can be expressed as Eqs. 16– 17 and the correlation coefficients are r = ,r = respectively.As shown in Figs. 7 and 8 , the Nusselt number Nuand pressure drop will increase with the increase of Renumber.Under the same shell side velocity and with different tube velocity for SBSTHX the heat transfer and flow resistance characteristic are almost same, which prove the goodrepetition of the experiments. The parison of Nunumber and pressure drop D p inshell side between FBSTHX and SBSTHX can be seen in Figs. 9 and 10. Nusselt number Nu increases with the increase of Reynolds number Re for the two heat exchangers, and the pressure drop increases with the increase of the Reynolds number Re for both heat exchangers. From the figures it can be observed that, with same Renumber, the Nunumber of FBSTHX is about 50% of that of SBSTHX, but the pressure drop D p of the former is only 30% of that of the latter. This is because the fluid flow in shell side of flower baffle heat exchanger is longitudinal, but the fluid flow in shell side of segmental baffle heat exchanger is transverse. As a result, the heat transfer of the flower baffle heat exchanger is less than that of the segmental baffle heat exchanger. Because of this, the pressure drop in shell side of flower baffle is also less than that of the segmental baffle heat exchanger.Figure 11shows the prehensive parison of performance Nu/ Dp between FBSTHX and SBSTHX. With sameRenumber, the prehensive performance Nu/ Dp of FBSTHX is about 60% higher than that of SBSTHX.To sum up, in the same shell side Re, the shell side Nuof FBSTHX is less than that of the SBSTHX, and the pressure drop of the former is also less than that of the latter, but the decreasing amplitude of the flow resistance is larger than that of the heat transfer. As a result, the prehensive performance Nu/D p of FBSTHX is higher than that of the SBSTHX. Therefore, it could be concluded that with same pressure drop, the Nunumber of the FBSTHX is higher than that of the SBSTHX.6 Experimental uncertainty analysisThe experimental uncertainty of the present work is determined by using the method presented by Ref. [14].The uncertainty calculation method involves calculating derivatives of the desired variable with respect to individual experimental quantities and applying known uncertainties. According to Ref. [ 14], the experimental uncertainty is defined as follow:Where R=f（Ｘ1，Ｘ2，...，Ｘn），Ｘ1，Ｘ2，...，Ｘn are the variables that absolute uncertainties of Ｘ1，Ｘ2，...，Ｘn.The uncertainties involved in the friction factors for FBSTHX and SBSTHX are 177。ho , heat transfer coefficient for shell side, W/(m2K)。序號項目符號單位數(shù)據(jù)來源和計算公式數(shù)值1殼程圓筒材料線膨脹系數(shù)GB15019981062換熱管材料線膨脹系數(shù)GB15019981063換熱管與殼程圓筒的膨脹變形差1044沿長度平均的殼程圓筒金屬溫度工藝給定1605沿長度平均的換熱管金屬溫度工藝給定1106制造環(huán)境溫度207當量壓力組合8有效壓力組合Pa9基本法蘭力矩系數(shù)10管程壓力下的法蘭力矩系數(shù)10411管板邊緣力矩系數(shù)10312管板邊緣剪切系數(shù)13管程總彎矩系數(shù)14系數(shù)=max{，}15殼體法蘭力矩系數(shù)10316管板徑向應力系數(shù)10317管板的徑向應力83．9318管板布管區(qū)周邊外徑向的應力系數(shù)19管板布管區(qū)周邊外徑向的應力20管板布管區(qū)周邊的剪切應力系數(shù)21管板布管區(qū)周邊的剪切應力25．9822換熱管的軸向應力=[PcPa]23換熱管與管板連接的拉托應力c、只有管程設計壓力Pt，而殼程設計壓力Ps=0，不計膨脹節(jié)變形差時：序號項目符號單位數(shù)據(jù)來源和計算公式數(shù)值備注1當量壓力組合2有效壓力組合Pa=∑sPt+βrEt3管板邊緣力矩系數(shù)4管板邊緣剪切系數(shù)5管板總彎矩系數(shù)6系數(shù)7管板的徑向應力8管板布管區(qū)周邊外徑向的應力系數(shù)9管板布管區(qū)周邊外徑向的應力10管板布管區(qū)周邊的剪切應力系數(shù)11管板布管區(qū)周邊的剪切應力12換熱管的軸向應力=[PcPa]13殼程圓筒的軸向應力=A/AsPa14換熱管與管板連接的拉托應力d、只有管程設計壓力Pt，而殼程設計壓力Ps=0，同時計入膨脹變形差時：序號項目符號單位數(shù)據(jù)來源和計算公式數(shù)值備注1換熱管與殼程圓筒的膨脹變形差r1042當量壓力組合Pc3有效壓力組合Pa4基本法蘭力矩系數(shù)1．7271065管板邊緣力矩系數(shù)1036管板邊緣剪切系數(shù)7管程總彎矩系數(shù)8系數(shù)=max{，}0．2159管板布管區(qū)周邊外徑向的應力系數(shù) 10管板布管區(qū)周邊外徑向的應力系數(shù)11管板布管區(qū)周邊的剪切應力系數(shù)12管板布管區(qū)周邊的剪切應力13換熱管的軸向應力 =[PcPa]14換熱管與管板連接的拉托應力H、由管板計算厚度來確定管板的實際厚度：序號項目符號單位數(shù)據(jù)來源和計算公式數(shù)值備注1管板計算厚度2殼程腐蝕裕量23管程腐蝕裕量24結構開槽深度根據(jù)結構確定35管板的實際厚度23考慮圓整是否安裝膨脹節(jié)的判定 由G，a、b、c、d計算結果可以看出：四組危險組合工況下，換熱管與管板的連接拉托力均沒超過設計許用應力，并且各項應力均沒超過設計許用應力。所以可以計算出總傳熱系數(shù)為：則傳熱系數(shù)比為：(合理)所以假設合理。但空心環(huán)支承的擾流作用不如折流桿支承,而且管束固定工藝相對較復雜。、30176?？v流形支承結構的特征是殼程流體的流動方向與管束平行,這類換熱器基本實現(xiàn)了殼程、管程流體的完全逆流,增大了有效平均溫差,提高了傳熱效果?？s放管應用于單相流的研究已開展很多。這是由瑞士Allares公司首先提出的一種換熱管。近年來隨著節(jié)能技術的發(fā)展,換熱器的應用領域不斷擴大,帶來了顯著的經濟效益[2]。世界各國在尋找新能源的同時，也更加注重了節(jié)能新途徑的研發(fā)。 換熱器換熱過程是為了實現(xiàn)下列目的：⑴通過減小設計傳熱面積來減小換熱器的體積和質量⑵．提高已有換熱器的換熱能力⑶．使換熱器能在較低額溫差下正常工作⑷．通過減小換熱器的流體阻力來減少換熱器的動力消耗2 國內外發(fā)展狀況 換熱管是管殼式換熱器的主要組成部分，以下是列舉的集中國內外新型高效換熱管以及它們的作用 螺旋槽管是一種管壁上具有外凸和內凸的異形管,管壁上的螺旋槽能在有相變和無相變的傳熱中明顯提高管內外的傳熱系數(shù),起到雙邊強化的作用。 該公司還開發(fā)了一種叫HitranMatrixElements的花環(huán)式插入物,能在不增大壓降的條件下大大提高傳熱系數(shù)。陳穎[8,9]經實驗和模擬計算,表明該改進型縮放管有較好的強化傳熱效果。另一類是設有中心管,折流板為整體連續(xù)的螺旋結構。的綜合性能最好。綜上所述,隨著強化傳熱理論的研究,加強管殼式換熱器的改進,將高效傳熱管與殼程強化傳熱的支撐結構相結合是今后換熱器發(fā)展的一個重要方向。A、確定殼程圓筒、管箱圓筒、管箱法蘭、換熱管等元件結構尺寸及管板的布管方式；以上項目的確定見項目一至七。 折流板尺寸缺口弦高值，