Fluid flow and heat transfer in pipework systems: I Mathematical model for dynamic modular simulation

A general-purpose simulation software package ('Bristol') is used for the simulation of variable fluid flow pipework systems. The simulation solves the fluid pressure and mass flow in pipe networks and in addition computes the non-steady state heat transfer through the pipe wall to the environment. The simulation package is intended to assist engineers or designers to solve design problems, and an example is included to illustrate how it could be used in the design of a hot water supply system. The program not only takes up the task of tedious arithmetic but also gives information that cannot be obtained from conventional design calculations. The potential and drawbacks of modular simulation systems for design in general are also discussed. This paper (Paper I) describes the mathematical models of pipework components and nodes followed by an introductory example of a pipe network. Paper II will continue with a design example together with conclusions and discussion on future work.