Method for controlling a reforming reaction by measurement of the temperature of the reforming tubes and functional parameter modification

摘要

The invention relates to a method for controlling a hydrocarbon vapor reforming reaction using a combustion chamber containing burners and tubes, said tubes being filled with catalysts and capable of being crossed by a mixture of hydrocarbons and vapor, the burners being arranged so as to transfer their combustion heat to the mixture of hydrocarbons and vapor through the walls of the tubes, wherein the temperature T of the wall of each tube is measured in the downstream part of the tube, and if for at least one tube, the measured temperature“is higher or equal to the MOT (DTT-15° C.), DTT being the design temperature of the measured tube, the functional parameters of the reforming method are then modified so as to decrease the measured temperature T of this tube down to a value lower than the MOT.

主权项

1. A method for controlling a hydrocarbon steam reforming process carried out in a combustion chamber comprising burners and tubes, the tubes being filled with catalyst and being capable of being passed through by a mixture of hydrocarbons and steam, the burners being positioned so as to transfer the heat from their combustion to the mixture of hydrocarbons and steam through the wall of the tubes, the method comprising the steps of:
measuring a wall temperature T of each tube; and modifying at least one operating parameter of the reforming process when, for at least one tube, the measured wall temperature T is greater than or equal to a maximum operating temperature of the tubes, so as to lower the wall temperature T of said tube to a value below the maximum operating temperature of the tubes wherein the wall temperature T of the tube is deduced from a value Tm indicated by a pyrometer when it is aimed directly at the tube and from an average temperature Tw of a wall of the combustion chamber in the vicinity of the tube from the formula:T⁡(Kelvin)=14388/(λ⁢⁢ln[1+ɛ1ⅇ14388/λ⁢⁢Tm-1-(1-ɛ)ⅇ14388/λ⁢⁢Tw-1]) in which: T is the wall temperature in Kelvin; λ is the wavelength of the pyrometer in μm; Tm is the temperature indicated by the pyrometer when it is aimed directly at the tube, in Kelvin; Tw, in Kelvin, is the average of a plurality of temperature measurements taken from the wall of the combustion chamber on both sides of the tube; and ε is the emissivity of the tube.