Transient heat loss from thermal insulation pipe.

Abstract

In transferring heat energy by fluid, it is well known that heat capacity of piping affects the heat loss at the transient state. Above all, heat loss from the piping of a solar collector system is one of the most important subjects from the viewpoint of increasing the performance of a system utilizing solar thermal energy. For reducing heat loss from the piping, we manufactured a piping made of only thermal insulation material, which we called a thermal insulation pipe; i.e., TIP. In order to demonstrate its effectiveness, we performed experiments of transient temperature response of the outlet of a piping system in comparison between a TIP and a piping which is composed of a metal pipe covered with thermal insulation material which we called ordinary insulation piping; i.e., OIP. Furthermore, numerical calculations and simple analysis of transient heat loss in both piping system were performed. This paper describes the effectiveness of the TIP from the comparison of the major results of experiments and calculations.