Design method and software development for the spiral-wound heat exchanger with bilateral phase change

Based on VB6.0, this paper has developed a new design software for the spiral-wound heat exchanger (SWHE) with bilateral phase change using segmented calculation method, by which the SWHE was divided into five segments, based on the different temperature of phase transition points of two heat transfer mediums in the shell side and the tube side. Then design of each segment was conducted according to the corresponding process conditions, finally the whole design of the SWHE was obtained. The results gotten from the software design was compared with the data from the actual engineering, which showed that the error of the outlet temperature was less than 2% and the error of the pressure drop was less than 5%. According to the design method, this paper also analyzed the influence of structural parameters, such as the diameter of the heat transfer tube (15-20 mm), the diameter of the core barrel (400-1000 mm) and the length to diameter ratio (5-10), on the comprehensive performance of the SWHE. As a result, the length to diameter ratio influenced the heat transfer area and pressure drop greatly. Because the design software is found to be accurate, quicker and more efficient, it can be used for the design calculation and check calculation for the SWHE with bilateral phase change.