The Methods Study Of Hydraulic Calculation Of Ship Network

After the main equipments in marine systems are fixed, next step is to select and optimize the pipeline and pipeline equipments. The good selections of equipments and pipeline's optimization are based on accurate hydraulic calculation. The ship pipe network systems have become increasingly complex, as the improvement of the automation and complexity of the modern marine systems. But the ship designers are still using the original hydraulic calculation methods, by means of which there are some errors on hydraulic calculation of the simple piping systems and the calculation of complex pipe network will produced some larger and even cannot finished. Design and optimization of the pipe network system not only require the good methods of hydraulic calculation, but also rely on the comparison of a variety of design schemes and the simulation of abnormal working conditions.With the help of the modern mathematical tool of graph theory, the paper derives the hydraulic calculation formula applying to ship network from Bernoulli equation and Continuity equation, and introduces the calculation processes in view of the various types of the hydraulic calculation of ship network. The hydraulic calculation formula which is put forward in this is proved correct by the flux calculation of "YUKUN" boiler feed water network by means of the different methods. To make the marine system more rational, a calculation mathematical model of stable flow field of changed network is established and this mathematical model is used for comparison of a variety of design schemes and simulation of abnormal working conditions. When solving nonlinear equations, we calculate by means of the method which combines Hardy-Cross method with the quasi-Newton method. Not only does this method avoid the error produced by the Hardy-Cross method, but also overcomes the shortcomings of quasi-Newton method. Practicality, efficiency and accuracy of the calculation model of stable flow field of changed network are verified by the simulation of "YUNKUN" ballast system and the pressure calculation of "YUNKUN" boiler feed water network. Finally, through the tests of "YUKUN" boiler water-supplying conditions, the mathematical model built in this paper and usability of the ship hydraulic calculation software are further verified. The Mathematical model of hydraulic calculation of pipe network will be of great guiding and reference significance to the hydraulic computation of ship network in future.