| 1. | Refer to some application examples of inner trachea tubular air pre - heater in power plants it is a good replacement pipe of the old smooth pipe
所以，在用内螺纹管代替光管进行管式空预器的设计时，需要进行全面的核算。 |
| 2. | The mesh of copper tubes and loading ways of the balls are the key problems during three dimensional fe simulation of ball spinning of inner grooved tubes
摘要内螺纹管滚珠旋压三维有限元模拟中，铜管的网格划分和滚珠加载方式是模拟的关键问题。 |
| 3. | Successfully simulated and replayed the complicated ball spinning of inner grooved tubes through the establishment of simplified sixth rotational symmetrical fe model and the adapting of local remeshing techniques
通过建立简化的六分之一旋转对称模型和采用网格局部重划分技术，成功地模拟和再现内螺纹管滚珠旋压成形过程。 |
| 4. | 4 . the effects of geometrical parameters of microfin tubes on the in - tube boiling heat transfer coefficients is analyzed . in addition , the principles on intensifying heat transfer in microfin tube is also analyzed
对r290和r404a ，通过研究koyama和thome关联式，分析了内螺纹管齿高、螺旋角等齿型参数对工质沸腾换热性能的影响。 |
| 5. | The objective of this dissertation is to conduct on theorical analysis and calculation upon flow boiling heat transfer inside horizontal smooth and microfin tube of r290 and r404a , which are newly environmental replacements of r22
研究了文献中的几个通用性较好的光管、内螺纹管沸腾换热系数计算关联式，并深入分析了各内螺纹管沸腾换热系数关联式的联系与区别。 |
| 6. | The type of heat transfer inside the pipes belongs to single - phase compulsive turbulent flow of inner pipe . inner trachea is a kind of special pipe compared by smooth pipe , which can strengthen heat transfer inside pipe
空预器烟气侧的换热类型是管内单相强迫紊流换热，论文在查阅了相关文献的基础上，比较了几种不同的管内强化换热措施，在其中选择内螺纹管代替光管，来改造管式空气预热器。 |
| 7. | Abstract : this paper analyzes theoretically the effect of the reversed cone angle and length of the plug on restraint and elimination to the distortion of the internal spiral ribs , and put forth the design methods of the plug in drawing rifled tube
文摘:从理论上分析了芯棒倒锥角和芯棒长度对内螺旋凸筋形状畸变的抑制和消除作用，提出了采用倒锥形等螺距芯棒拉拔内螺纹管时芯棒几何参数的设计方法。 |
| 8. | Thome correlation has good precison in calculating heat transfer coefficients of r404a inside horizontal microfin tube . 3 . the analyses on different empirical formulations of in - tube boiling heat transfer coefficients indicate that r404a can be treated as pure refrigerant during calculating its the in - tube boiling heat transfer coefficients
对近共沸混合工质r404a ，通过对光管和内螺纹管沸腾换热系数关联式的分析计算得出结论：在计算r404a的光管和内螺纹管沸腾换热系数时可以被作为纯质来处理。 |
| 9. | There are a lot of advantages when inner trachea applied in air pre - heater , such as the improvement of the temperature of pipe , the low consumption of metal , except for the increment of flow resistance . according to many related papers , it is more proper inner trachea with the structure of short distant between two whorls and shallow depth of whorl . it can enhance heat transfer with smaller flow loss
内螺纹管是一种异形管，和光管相比，管内侧的换热系数大大增强了，应用于空气预热器可以起到提高总传热系数、节约受热面金属消耗量的目的；同时提高了管壁温度，能够减轻低温腐蚀的程度和速度；不足之处是带来了更大的阻力损失。 |
| 10. | Taking some tubular air pre - heater used in one boiler whose capacity is 130 t / h as an example , new blue print with inner trachea is completed by means of computer program . several key design variables may be changed , such as diameter of pipe and velocity of flow of gas . these cases have been considered , and their results have also been compared with each other
比较了几个重要的设计变量，如外管径、烟气流速等参数变化时，总传热系数和空预器本体管子总重量，阻力损失以及最低管壁温度等几个重要设计结果的变化趋势，对内螺纹管空气预热器的设计具有借鉴意义；其间还分析了内螺纹管与光管在设计时的不同之处；最后，初步分析了内螺纹管的优化设计问题，提出了一些建议。 |
