Temperature measurement with a suction pyrometer in an entrained flow reactor

摘要

Measuring the temperature of hot gases is important in characterizing a combustion environment. This measurement can not always be accomplished accurately with a thermocouple because of conduction along the thermocouple wire and because of the radiative heat exchange between the thermocouple, the gases, suspended particles and the walls of the reactor. Therefore, in situations where the convection is not dominant over other heat transfer modes (radiation or conduction) the temperature measured by a thermocouple does not represent the actual temperature of gas. This situation is problematic in furnace environments when the wall temperature differs from the gas temperature and the gas velocity is low. In practice, the true temperature of the gas can be estimated either by correcting the measured value by using the equations for the errors mentioned above or by using a suction pyrometer. The goal of this study is to quantify the uncertainty in the correction approach by comparing thermocouple and suction pyrometry measurements in an entrained flow reactor. The pyrometer was custom designed and built for the small size of our reactor in order to minimize thermal perturbations on the flow.