Dynamic characteristics of various shell-and-tube heat exchangers and modeling from the viewpoint of the network theory

This paper presents a network-theoretical approach to the modeling on the dynamic characteristics of the shell-and-tube heat exchangers. Taking into account the phase conditions of hot and cold fluids upon heat-exchange, the shell-and-tube heat exchangers are classified into four types. At the same time, not only the steady state but also dynamic characteristics of the heat exchangers are classified into four types. Therefore they are usually considered and treated as different heat exchangers. In this paper, the dynamic characteristics of the four types of shell-and-tube heat exchangers are investigated theoretically. As a result, we derived the model on the dynamic characteristic of each type of the heat exchangers from the viewpoint of the network theory. In this model, the hot and cold fluid processes are represented as 2-port network elements interconnected, and each process consists of through variable sources and admittances in parallel. According to this model, the investigation on these admittances gives us important information on the dynamic characteristics of the shell-and-tube heat exchangers.