塔的计算方法与收敛？ the simple estimate generator computes tray flows from constant molar overflow and the temperatures and mole fractions from l/f flashes. the conventional estimate generator uses the fenske method to determine product mole fractions as follows: 􀂄 erform shortcut fenske calculations to determine the product splits and compositions. the flows from the product information are used to initiate the shortcut calculations and, when possible, the performance specifications desired for the rigorous solution will be used for specifications. note that only specifications pertaining to the product rates or compositions have any meaning for the shortcut model, i.e., rigorous specifications such as tray temperatures and tray flows (including reflux) have no meaning. when rigorous specifications cannot be used, the initial estimate generator will use alternate specifications selected in this order: the rate from the product information, and a fractionation index (fenske trays) equal to approximately 1/2 of the column theoretical trays. based on the shortcut results the product temperatures are calculated. any user-provided temperatures are used directly. the column liquid loading is calculated by using the reflux estimate provided by the user. note that an l/d ratio of 3.0 is assumed if no reflux quantity is provided. a column heat balance is performed. if side coolers are present and duties have been provided, the flow profiles are appropriately adjusted. the refining estimate generator uses the fenske method just like the conventional estimate generator. the four steps described above for the conventional method are repeated here. in addition, the bottom tray temperature is adjusted for the effect of stripping stream, if present. adjustment is also made for inter-linked columns if present.the simple estimate generator computes tray flows from constant molar overflow and the temperatures and mole fractions from l/f flashes. 个人感觉对收敛和结果无决定影响.查看更多
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