Investigation of heating characteristics of domestic gas cookers via a methodology of infrared thermography

摘要

The heat flux measurement method based on the infrared thermography technique is first applied to study the heating characteristics of domestic gas cookers. Unlike the traditional means of heat flux measurement, the infrared thermography technique is non-intrusive and can help measure the heating flux distribution within two-dimensional space, which is very interesting to design and optimization aspects. The evolution of the temperature field of a heated pan is recorded to calculate the heating flux using the two-dimensional unsteady heat balance equations and inverse method. The heat radiation and natural convection can either be estimated or neglected in the calculation of the heating flux. Resistance foils with known electro-heating power are applied as the heating source to validate the feasibility and accuracy of this method. The uncertainty analyses show a maximum error of 15% in the local distribution and the error of 6% for the power. The heating flux distributions are measured for six gas cookers with different power modes. The results clearly reflect the mechanisms of the heat flux distributions linking to the designed structures of the burners. A dimensionless unevenness factor derived from the uniformity of heating flux distribution is defined for a better understanding of the locally overheating problems.