Research on on-site measurement factors and performance of coal calorific value based on laser ignition

Abstract

The laboratory method used for coal calorific value measurement has a significant hysteresis. In this paper, an on-site measurement method of coal calorific value based on high power laser rapid ignition is proposed. The effects of oxygen transverse passage velocity, thermal insulation crucible bracket and coal samples on the measurement time, unburned rate and calorific value measurement error are gradually investigated. The experimental results shows that the measurement error of calorific value is within 2% and unburned rate is within 2% at the oxygen transverse passage velocity of 120 mm/s of Huainan bituminous coal. Then the utilization of porous thermal insulation crucible bracket has shown a good performance in heat dissipation to shorten the measurement time without increasing the unburned rate. Then, the effects of coal sample thicknesses, species and particle sizes on calorific value measurement are investigated. Results show that under the coal thickness from 4.2 to 5.4 mm, the calorific value measurement error is within 3%, and the unburned rate is within 2% of Huainan antiminous coal. Finally, the results shows that the method has a good performance on different coal species and particle sizes which the calorific value measurement error is within 5%. This research quantifies the effects of the experimental condition parameters on the measurement of coal calorific value based on laser ignition, which lays the foundation for the subsequent development of online coal calorific value meter.