Independent temperature control method and system for multi-zone graphite furnace

Abstract

The invention relates to the technical field of ohmic resistance heating treatment, in particular to an independent temperature control method and system for a multi-zone graphite furnace. The method comprises the following steps: applying step-type power excitation to a current temperature zone; obtaining the temperature steady-state variable quantity of the adjacent temperature zones under step type power excitation so as to determine the real-time thermal coupling coefficient of the current temperature zone to the adjacent temperature zones; calculating feed-forward decoupling compensation power of the current temperature zone according to the material thermal disturbance compensation power, the flow velocity of the carbon fiber, the mass per unit length, the specific heat capacity and a difference value between the target operating temperatures of the current temperature zone and the upstream temperature zone of the current temperature zone; adding the standard PID output power of the temperature zone, the feedforward decoupling compensation power applied to the current temperature zone by all adjacent temperature zones and the material thermal disturbance compensation power to obtain total output power; and the electric power of the temperature zone heating system is controlled according to the total output power, so that the independent temperature control accuracy of the multi-zone graphite furnace is effectively improved.

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