Research On Calculation Method For Helical Wound Coil Tube Heat Exchangers

Helical wound coil tube heat exchangers are heat transfer installations in hypothermia apparatus, widely used in gasification of gas and rectisol process. By comparison with tube-type heat exchangers, helical wound coil tube heat exchangers have tight structure, large heat transfer surface, high heat efficiency and standing high pressure on the tubeside, etc.Synthesize ammonia of China's industry has of late years grown with leaps and bounds. On this background, the need for rectisol wash unit supplies will increase. At the same time, the demand for the retrofitting the primary device in technology that at last it can be expanded produces the transformation is increasing. In this situation, the manufacturing of domestic built-up helical wound coil heat exchangers is very important.This paper takes the helical wound coil tube heat exchangers in rectisol process as the main research object. A calculation method for helical wound coil tube heat exchangers is proposed and a mathematical model for this kind of exchanger is presented in this paper. Simulation of two types of helical wound coil tube heat exchangers are completed with some compilers for programs written in FORTRAN.The first type is two-stream helical wound coil tube heat exchangers without phase-change like E8 lean methanol cooler (â…¢) and E9 lean methanol cooler (â…¡). Simulation of the helical wound coil heat exchangers E8,E9 of the original design capacity,110% flow rate and 130% flow rate is carred out.The second type is two-stream helical wound coil tube heat exchangers with phase-change on the shellside like E7 methanol/methanol heat exchanger. Simulation of the helical wound coil heat exchanger E7 of the original design capacity,110% flow rate and 130% flow rate is carred out.By comparison, the errors of the data of average coiling diameter, heat transfer coefficient and pressure loss of these exchangers obtained using the mathematical model are very small from the original design data. The result shows that the model is basically reasonable and reliable. It can be the reference for the design of helical wound coil tube heat exchangers, expanding produces the transformation, and performance evaluation.