چكيده به لاتين
The oil and gas industry is one of the most important industries in Iran. Meanwhile, gas has many applications in the country's industrial sectors and many consumers are requesting to use its energy In order to transfer natural gas from the refinery to the consumer, transmission and distribution network is needed. By using different devices and meters it is possible to calculate the amount of passing gas but its quality changes in different parts of the network under factors such as temperature, pressure, etc. Indexes such as methane number and Wobbe index are considered for gas quality analysis. Using a gas chromatography device is the most accurate way to measure gas quality; Of course, buying and maintaining this device is very expensive. Therefore, in some parts of the network, other devices such as dew point analyzer, density meter and Q1 gas device are used. In the gas transmission and distribution network, modeling and simulation can be done by using technology and specialized software in the industry to save time and money. With this point of view, in this research and according to the mentioned needs, the software for simulating the gas transmission and distribution network and predicting its quality has been investigated. Modeling and simulation of gas transmission and distribution network was done in MATLAB software that acceptable results were obtained from it. Data from articles from China and Norway were used for validation. The investigated equations are: continuity, momentum, energy, partial mass, which are used for pressure, flow, temperature and percentage composition calculations, respectively. In this research, GERG-2008 equation of state was chosen. To solve the system of nonlinear algebraic equations resulting from the discretization of the system of governing PDE equations, the finite difference method was used. The Newton-Raphson method, which is an iterative method, was used for numerical solution and favorable results were obtained by the fully implicit method. In this research, firstly, validation of the modeling was done with two cases of single pipe design. Then, in the second scheme, validation was carried out by using a network of connected pipes from which a good match was obtained. For the final part of this research, the data of Iran Gas Transmission Company was used. This network started from the south of the country (Persian Gulf Bidbland refineries and phases 1, 2 and 3 of South Pars) and extends to Gilan and Mazandaran provinces. After these actions, by using the graphic user interface of MATLAB software the simulation software of natural gas quality in the transmission network was designed.
