Analysis of the Single-Blow Transient Testing Technique for Non-metallic Heat Exchangers

For measuring the efficiency of non-metallic heat exchangers, a mathematical model was established based on the principle of the single-blow testing technique, in which the conductive thermal resistance across non-metallic plates of the exchangers was taken into account. The analytical solution was obtained by means of the Laplace transformation and numerical invers transform method. The accuracy of the model was verified by comparing it with the literature. The effect of the plate Bi number on the evaluated NTU was analyzed. Based on the single-blow transient testing technique and the present model, the heat transfer performance and frictional pressure drop of four types of non-metallic plates with different structural parameters were experimentally studied. The correlations for heat transfer and frictional pressure drop of non-metallic heat exchange structures are established.