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经对国外换热器市场的调查表明,虽然各种板式换热器的竞争力在上升,但管壳式换热器仍占64％的市场份额,取主导地位。随着科学技术的发展,工业设备也向着高温、高压、大型化方向发展。从而促就换热器结构也有不少新的发展。现就几种新型换热器的特点简介如下:1.气动喷涂翅片管换热器 俄罗斯提出了一种先进的用高速的冷的或稍加温的含微粒流体给翅片表面喷镀粉末粒子,以提高翅片化表面的性能。 通常,翅片底面的接触阻力是限制管子加装翅片的因素之一。为了评估翅片管换热器元件,进行了在翅片表面喷涂AC—铝,并添加了24A白色电炉氧化铝的试验。将试验所得数据加以整理后的结论是:气动喷涂翅片的底面的接触阻力对效率无实质性影响。为了证实这一点,又对基部(管子)与表面(翅片)的过渡区进行了金相结构分析。结果表明:连接边界的整个长度上无不严密性的微裂纹。所以,气动喷涂法促进表面与基体相互作用的分支边界的形成,能促进粉末粒子向基体的渗透,这就说明了附着强度高,有物理接触和金属链形成。
After the investigation of foreign heat exchanger market shows that, although the competitiveness of various plate heat exchangers are on the rise, but the shell and tube heat exchanger still accounts for 64% market share, take the leading position. With the development of science and technology, industrial equipment has also been developed towards high temperature, high pressure and large scale. Thus promoting the heat exchanger structure also has many new developments. Now on the characteristics of several new heat exchanger profile is as follows: 1. Pneumatic finned tube heat exchanger Russia has proposed an advanced high-speed cold or slightly warm fluid containing particles to the fin surface powder coating Particles to improve the performance of the finned surface. In general, the contact resistance of the bottom surface of the fin is one of the factors that limits the fins in the tube. In order to evaluate finned tube heat exchanger components, tests were carried out by spraying AC-aluminum on the fin surface and adding 24 A white EAF. The test data obtained after finishing the conclusion is: the bottom of the aerodynamic spray fin contact resistance has no substantial effect on the efficiency. To confirm this, a metallographic analysis of the transition zone between the base (tube) and the surface (fin) was performed. The results show that the entire length of the connection boundary is free from micro-cracks. Therefore, the formation of branch boundaries that promote the interaction of the surface with the substrate by the pneumatic spray method can promote the penetration of the powder particles into the substrate, which shows the high adhesion strength, the physical contact and the formation of metal chains.