舉例說明翅片管換熱器換熱面積的計算方式

翅片管的傳熱原理用普通的圓管(光管)組成的熱交換器，在很多情況下，管外流體和管內流體對管壁的換熱系數是不一樣的。所謂換熱系數，是指單位換熱面積，單位溫差(流體與壁面之間的溫差)時的換熱量，它代表流體和壁面之間的換熱能力的大小。翅片管換熱器的設計工藝中，一臺翅片管的換熱面積就是每根翅片管換熱面積的總和。知道瞭翅片管的換熱面積，就能有效的清楚每臺翅片管換熱器的換熱面積為多少。The heat transfer principle of finned tube is a heat exchanger consisting of a common round tube (light tube). In many cases, the heat transfer coefficients of the fluid outside the tube and the fluid inside the tube to the tube wall are different. The so-called heat transfer coefficient refers to the amount of heat transfer per unit heat transfer area and per unit temperature differen彩色沥清地坪ce (the temperature difference between the fluid and the 环氧地坪wall), which represents the heat transfer capacity between the fluid and the wall. In the design process of finned tube heat exchanger, the heat transfer area of one finned tube is the sum of the heat transfer area of each finned tube. Knowing the heat transfer area of finned tube can effectively clarify the heat transfer area of each finned tube heat exchanger.舉例說明翅片管換熱器換熱面積的計算方式：An example is given to illustrate the calculation method of heat transfer area of finned tube heat exchanger.翅片管型號為：CPG (Φ25×2mm/57/2.8/0.35) 求每米翅片管的換熱面積？The fin tube type is CPG (25 * 2mm/57/2.8/0.35), and the heat exchange area of each fin tube is calculated.解答：Answer:翅片管換熱器的總面積等於翅片管的裸露部分面積+翅片面積The total area of finned tube heat exchanger is equal to the bare part area of fin tube and fin area.翅片管裸露部分面積=3.14X0.026X(1000—(1000/2.8)X0.35)=0.071435㎡The exposed area of finned tube is =3.14X0.026X (1000 - (1000/2.8) X0.35) =0.071435翅片部分的面積=3.14X(0.0285?-0.013?)X357X2+3.14X0.057X0.125=1.4645125㎡The area of the fin part =3.14X (0.0285? -0.013?) X357X2+3.14X0.057X0.125=1.4645125?翅片管總的換熱面積=0.071435+1.4645125=1.536㎡/m.The total heat transfer area of fin tube is =0.071435+1.4645125=1.536 /m.即該型號翅片管的換熱面積為1.536㎡/米。That is, the heat exchange area of the finned tube is 1.536 / M. 水在壁面上凝結時的換熱系數為： 10000—20000 w/(m2.℃)When the water condenses on the wall, the heat transfer coefficient is 10000 - 20000 w/ (m2. C).水在壁面上沸騰時的換熱系數為： 5000----10000 ------When the water is boiling on the wall, the heat transfer coefficient is 5000----10000 -水流經壁面時的換熱系數大約為： 2000---10000 ------The heat transfer coefficient of water passing through the wall is about 2000---10000.空氣或煙氣流經壁面時的換熱系數為： 20---80 --- ---The heat transfer coefficient of air or flue gas passing through the wall is 20---80 -空氣自然對流時的換熱系數隻有： 5---10 -------The heat transfer coefficient of, natural convection is only 5---10: -由此可見，流體與壁面之間的換熱能力的大小相差是很懸殊的。It can be seen that the difference in heat transfer capacity between the fluid and the wall is very different.