Sizing of gas transmission pipelines

U ovom diplomskog radu obrađena je tema projektiranja i dimenzioniranja magistralnih plinovoda. U prvom dijelu rada kratko su opisane karakteristike prirodnog plina i transportnog sustava prirodnog plin u Hrvatskoj. Potom slijedi osvrt na svojstva plina koje direktno utječu na samo projektiranje i dimenzioniranje magistralnih plinovoda, a to su gustoća, viskoznost, trojna i kritična točka, agregatno stanje i Joule–Thomsonov efekt. Navedena svojstva su prikazana u raznim dijagramima koji su izrađeni pomoću excele Coolprop wrapper-a koji ima vrlo visoku točnosti podataka. Nadalje spominju se najbitniji dijelovi transportnog sustava plinovoda kao što su kompresorska stanica, mjerno-redukcijska stanica, otpremno-prihvatna čistačka stanica, blokadna stanica, katodna zaštita i telekomunikacijska mreža za potrebne plinovoda. Također su obrađene karakteristike plinovoda kao što su optimalni promjer, kapacitet plinovoda, akumulacijska moć plinovoda i materijali plinovoda. U nastavku diplomskog rada izrađeni su proračuni dvaju primjera magistralnih plinovoda u hrvatskoj i to na relacijama Pula – Karlovac i Slatina – Našice. Proračuni obuhvaćaju izračun pada tlaka plinovoda formulom nestlačivog strujanja, formulom izotermnog i ekspandirajućeg strujanja i Renouardovom formulom. Također izračun pada tlaka je izračunat koristeći faktor stlačivosti, zanemarivanjem faktora stlačivosti te korištenjem točnijih podataka Coolpropa. Svi dobiveni podaci pada tlaka su međusobno uspoređeni . Proračun isto tako obuhvaća i izračun akumulacijske moći plinovoda kao i snage potrebne za kompresiju plina na radni tlak plinovoda, brzine strujanja, faktora stlačivosti, faktora trenja, reynoldsovog broja i drugih karakteristika strujanja plina. Proračun završava procjenom kapitalnih i pogonskih troškova plinovoda. Dok sami rad završava opisom puštanja plinovoda u pogon i postupcima ispitivanja čvrstoće i nepropusnosti.This thesis deals with the topic of sizing main gas transmission pipelines. The first part of the paper briefly describes the characteristics of natural gas and the natural gas transport system in Croatia. This is followed by a review of the properties of the gas that directly affects the design and dimensioning of main pipelines, such as density, viscosity, triple and critical point, physical state and Joule - Thomson effect. These properties are shown in various diagrams made using Excel CoolProp wrapper, which has a very high data accuracy. Furthermore, the most important parts of the pipeline transport system are mentioned, such as the compressor station, the measuring-reduction station, the dispatch-receiving cleaning station, the blocking station, the cathodic protection, and the telecommunication network for the normal functioning of gas pipelines. The characteristics of the pipeline, such as the optimal diameter, capacity of the pipeline, accumulation power of the pipeline and the materials of the pipeline are also mentioned. In the continuation of the diploma thesis, calculations of two examples of main gas pipelines in Croatia were made, on the routes Pula - Karlovac and Slatina - Našice. The calculations include the calculation of the pipeline pressure drop by the incompressible flow formula, the isothermal and expanding flow formula, and the Renouard formula. Also, the pressure drop calculation was calculated using the compression factor, ignoring the compression factor, and using more accurate CoolProp data. All the obtained pressure drop data were compared with each other. The calculation also includes the calculation of the storage power of the pipeline as well as the power required to compress the gas to the operating pressure of the pipeline, flow rate, compression factor, friction factor, Reynolds number and other characteristics of gas flow. Calculation ends with an estimate of the capital and operating costs of the pipeline. The thesis itself ends with a description of the commissioning of the pipeline and procedures for testing strength and tightness