HITCH Computer Code: Chemistry and pH Estimates of Concentrating Aqueous Solutions

摘要

A computer code HITCH has been developed to calculate the solution composition and the high-temperature pH of faulted aqueous environments during concentration by boiling at high temperature. The code includes hydrogen, hydroxyl, ammonium, sulfate, bisulfate, bicarbonate, chloride, sodium, magnesium and calcium ions, ammonia and carbon dioxide. The code written in BASIC language is formulated in two versions primarily for application to steam generator waters. The BULK model applies to bulk water that is converted to steam as it rises in the steam generator. Linear concentration factors are used over a range up to about 100 fold. The ISOLATED CAVITY model applies to solutions in heated crevices. Here, logarithmic concentration factors extend to higher ranges. Calculations in both models are stopped above 5 molal due to the limits of the present data base. The manual describes inputs, outputs, test cases and code options in detail for the user. (ERA citation 07:046690)