Abstract
The diameter of pipes in design of network of District Cooling and Heating (D.C.H.) plant was studied. At first, Hazen-Williams equation for hot and chilled water was apllied. And the constant friction loss method and constant velocity method were studied, but both methods were not available to decide diameters when the diameter of pipe changes in large range. Therefore, the calculation method for optimum pipe diameter to the tree-type network, using the objective function based on the cost of piping network under the speed limit of flow, was studied. Also, this research included the equation to the mesh-type piping network based on the method of Hardy-Cross for hot and chilled water. Consequently the computer programs of these equations were used and the comparison of several piping networks was studied.
