In this work I compared two programs for simulations of the uncontrolled release of hazardous substances in environment based on several different hydrogen chloride release scenarios. The free program ALOHA is a simplified program for simulations of the release of a substance or gas, while commercial program PHAST is more demanding and complex for use.
The introductory part of the work defines the characteristics of the programs, the model input data and the advantages/disadvantages of both programs. The properties of ammonia and hydrogen chloride are given and explained in the following. Ammonia was used only in the control simulation and hydrogen chloride in both the control and the experimental part simulations, where several release scenarios were considered. Two control simulations were performed to check the appropriate use of the PHAST program, and the results were compared to the literature data.
The aim of this work was to compare the results of the simulations of uncontrolled releases of two hazardous substances with the two mentioned programs. Two control simulations (for hydrogen chloride and ammonia) and four simulations of the release of hydrogen chloride during its storage and production use in the company were carried out. Despite the identical parameters taken into account in simulation, the two programs gave different results. The ALOHA program usually resulted two to three times larger areas of influence. The paid PHAST program enables easier transparency of the results, drawing of the impact area after 90 seconds of release and easier correction of the impact areas. Nevertheless, I believe that the ALOHA program is suitable for modeling the area of influence when producing risk assessments and safety reports, as it results larger areas of influence, which is applicable in terms of added safety.