Comparison Of Software Tools Between SES And STESS For Subway Thermal Environment

With the fast development of rail transit, SES and STESS are widely used in engineering design owing to their characteristics, such as smaller investment, simpler procedure and faster calculation. However, the designers have found that their simulation result for the same scheme is different, and the accuracy using them to verify and evaluate the scheme should be researched.To solve this problem, the comparison of two programs is studied from different views in this paper, which has theoretical and practical significance for better using or realizing energysaving.At first, we make some survey and confirm that the programs can simulate many operational conditions to evaluate the predictive capability of deterministic fire and ventilation models and then make optimization. Next, base on the real project, this paper detailed compares the input parameter, the simulation result and the calculation principle. After the comparison, we make following conclusions:(1) A large number of parameters need to be input for SES and STESS, however, they are described from different ways, which makes them inconvenient to use and causes the inconsistency of parameters. Both of them have great effect on the results.(2) STESS can simulate wind environment and thermal environment for three operation phases, which is correspond to the phased construction of subway in China. Based on the analysis of these results, engineering designers can know more about the global situation of subway operation and make better choice for construction and equipment installation.(3) The change trend of whole line mean flow is exactly similar under the same operation mode of air condition, however, the value in SES is more larger than that in STESS; The change trend and value of whole line mean temperature are big different between two programs, it is fluctuated greatly in STESS, but small in SES.(4) In the ventilation simulation, the mathematical model of two programs is same but STESS takes the new algorithm; In the temperature calculation, they both use the cylinder model, but the method of solving equations and analyzing heat sink is different. The difference of calculation principle is another important reason for the large different simulation results.