Judgment of the gasifier temperature

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The reaction temperature in the gasifier should be about 30–50°C higher than the flow temperature of the coal ash. Changes in the gasifier temperature are achieved by adjusting the oxygen-to-coal ratio; with a constant amount of coal slurry, an increase in oxygen supply leads to an increase in furnace temperature, while a decrease in oxygen supply results in a decrease in furnace temperature. In practice, the appropriate operating temperature should be determined based on changes in the composition of coal ash and its fusion point, so as to establish the optimal oxygen-to-coal ratio for operation. The general principle is: while ensuring proper slag discharge from the gasifier, to use as low an operating temperature as possible, reduce the oxygen-coal ratio, increase the content of useful gases, achieve the highest possible gasification efficiency, and extend the service life of the refractory bricks. There are several methods for detecting the temperature of the gasification furnace during actual operation: A) Thermocouples: Each gasification furnace is equipped with four thermocouples, and it is ensured that at least one of them indicates a normal reading when feeding material into the furnace. However, as the gasifier operates, the readings of the thermocouples may deviate. B) When the thermocouple readings are inaccurate, operations can be guided by the linear relationship between the methane content in the process gas and the furnace temperature. The relationship between methane content and the temperature of the gasification furnace is as follows: as the furnace temperature decreases, the methane content increases ； As the furnace temperature rises, the methane content decreases. At the same time, it can be adjusted in conjunction with the carbon dioxide content in the process gas. C) The residual carbon content in the coarse slag is 6-8%; due to the high carbon content, the furnace temperature is low. It can also be determined by the content of Cr2O3. D) The temperature of the gasification furnace can be determined based on the pressure of the on-site slag breaker; generally, a slag breaker pressure of 2–3% indicates that the pressure in the gasification furnace is appropriate ； If the pressure is 0%, it indicates that the temperature is too high and the slag is too fine ； If the pressure is 4% or higher, it indicates that there is a large amount of slag, the furnace temperature is too low, and there is a risk of blockage at the slag outlet. The temperature of the gasification furnace can be determined based on the ash. Normal ash should have a particle size of around 5 mm, a smooth surface, and an appropriate amount of ash – it is advisable that this amount make up more than 50% of the total ash volume. There is a significant amount of fine slag; the total amount of slag is not high, and there is no stringing phenomenon, which indicates that the furnace temperature is too high. However, the slag has good fluidity, so the temperature can be reduced appropriately to lower the oxygen-coal ratio ；