Heating control method for nitrogen oxygen sensor

Abstract

The invention discloses a heating control method for a nitrogen oxygen sensor. The nitrogen oxygen sensor comprises a signal function layer and a heater, wherein the heater is of a three-line type heater structure. The heating method comprises the following specific steps of: a, drawing a graph of a temperature value T of a nitrogen oxygen sensor chip and a head resistance value of the heater; b, when the temperature of the nitrogen oxygen sensor chip is determined to be 800DEG C, determining a resistance calibration value of the heater head to be R 800 and a voltage calibration value of the heater to be V800; and c, adjusting a heating voltage value of the heater for enabling a temperature value of the nitrogen oxygen sensor chip to be maintained at 800DEG C. According to the heating control method disclosed by the invention, the temperature value change of the head of the nitrogen oxygen sensor chip is characterized by adopting the amplitude of the head resistance value of the heater; and a work temperature value of the nitrogen oxygen sensor chip is enabled to be controlled at about 800DEG C by changing voltage values applied to two ends of the heater, and thus the measurement precision of the nitrogen oxygen sensor for NOx is further improved.

Description

technical field [0001] The invention relates to a nitrogen-oxygen sensor for an SCR system of a heavy-duty diesel engine, in particular to a heating control method for the nitrogen-oxygen sensor. Background technique [0002] The nitrogen and oxygen sensor chip consists of 6 layers of 5%molY 2 o 3 The stable zirconia electrolyte is laminated and composed of a signal functional layer and a heater. The signal functional layer mainly completes a series of electrochemical and catalytic decomposition reactions to measure NOx gas; the heater mainly heats the chip to make it Reach the temperature required for the electrochemical and catalytic reactions of the signal functional layer. The signal functional layer consists of three pump cells, two cavities, and a reference air channel. The two cavities communicate with the external measuring gas through the diffusion slit, and the reference air channel directly communicates with the atmosphere. There is a main pump battery in the ...

AI Technical Summary

Problems solved by technology

For the current-type nitrogen oxygen sensor, when the chip temperature changes, it will affect the characteristic curve of the pump current and pump voltage of the nitrogen oxygen sensor, causing a measurement error in measuring the pump current; in addition, if the chip temperature of the nitrogen oxygen sensor cannot reach When the temperature reaches 800°C, it will affect the catalytic decomposition ability of the measuring electrode to NOx. Both of these factors will cause errors in the measurement of NOx gas by the nitrogen and oxygen sensor.

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