Method for stimulating the circulation in evaporator heating surfaces and evaporator heating surfaces

摘要

A method for excitation of the liquid circulation in evaporator heating between the inlet and outlet headers, especially natural circulation in horizontally disposed convection heating surfaces, wherein the gas to be cooled stream is guided in cross-cocurrent to the circulating liquid, introduced, where the outlet headers hot circulating liquid or steam-liquid mixture which is drawn from the inlet header and charged through a Vorschaltheizfläche with heat is supplied, wherein the pressure loss of Vorschaltheizfläche is significantly lower than in the evaporator. The evaporator (6) for carrying out the process is between two collectors (3, 4) stretched evaporator (5) connected on the liquid side parallel and the gas side upstream, comprises a lesser number of headers and flue gas crossings and therefore lower flow resistance than the evaporator heating surface (5) and the outlet header (4) is connected via one or more connecting tubes (7) to the boiler drum (1).; The inventive method avoids evaporation at the beginning of an abutment of the Verdampferunlaufs in counter-current direction, the excessively high water discharge in the boiler drum and the occurrence of cooling difficulties, thus enabling an undisturbed natural circulation.