An Automatic Control Method of Oven Temperature Based on Slope Signal

Abstract

The invention discloses a method for automatically controlling the temperature of an oven based on a ramp signal. A furnace temperature controller and a furnace temperature transmitter are installed to configure the main loop of the control system, and a secondary loop of the control system is set on the fuel gas pipeline, which includes The furnace fuel gas flow sensor, furnace fuel gas flow transmitter, furnace fuel gas flow regulating valve, furnace fuel gas flow controller, furnace temperature controller and furnace fuel gas flow controller are configured. The output value of the furnace temperature controller is The given value of the furnace fuel gas flow controller, the furnace temperature as the control point, when the fluctuation of the fuel gas flow increases, the output value of the fuel gas flow controller decreases, the regulating valve is closed, and the fuel gas flow decreases; when the temperature fluctuates As the temperature rises, the output value of the temperature controller decreases, the set value of the fuel gas flow controller decreases, the fuel gas flow decreases, and the temperature drops, which can realize the automatic temperature rise and fall of the furnace according to the speed, improve the quality of the oven, and reduce the number of personnel. Labor intensity.

Description

technical field [0001] The invention relates to an automatic temperature control method, more specifically, an automatic temperature control method for an oven based on a ramp signal, and belongs to the field of petrochemical industry. Background technique [0002] Tubular heating furnaces are widely used in oil refining and chemical plants. During the construction of the heating furnace, the lining brick masonry and refractory castables contain a large amount of free water, crystal water and residual bound water. In case of cracking, bubbling, deformation or even collapse of the furnace wall, the heating furnace must be baked before commissioning to slowly evaporate and precipitate free water, crystal water and residual bound water, and sinter the furnace wall castable at high temperature . During the baking process, it is necessary to heat slowly and evenly according to the furnace curve corresponding to the characteristics of the castable product. Usually, the maximum te...

AI Technical Summary

Problems solved by technology

[0006] However, when the reaction product / reaction feed heat exchanger is a coiled tube heat exchanger, due to the very high heat exchange efficiency of the coiled tube heat exchanger, the temperature of the nitrogen circulated to the furnace inlet is relatively high, and the furnace temperature rises during the drying process. At 450°C, the nitrogen temperature at the furnace inlet has reached 320°C, and the nitrogen temperature at the furnace outlet has reached about 395°C, which is close to the reactor design temperature of 400°C. If the furnace temperature continues to rise, the reactor temperature will exceed the design temperature, causing damage to the reactor, and The temperature cannot continue to rise according to the oven curve. At this time, the oven program cannot continue, and the oven effect cannot be guaranteed, which will affect the service life of the heating furnace.

[0007] The existing heating furnace is only equipped with a furnace temperature transmitter, and only the furnace temperature can be monitored during the oven-drying period. When the fuel gas pressure, flow rate, and the amount of heat medium that can be carried by the furnace tube fluctuate, the furnace temperature will be disturbed. The temperature fluctuates greatly, which is not conducive to the quality control of the oven. Frequent manual adjustment of the opening of the fuel gas regulating valve is required, and the labor intensity of personnel is high.

Images