Level control in the process vessel using pumps driven by frequency converter

U radu je analiziran tehnološki proces i opisan princip rada postrojenja s dehidratorom i spremnikom slane vode u kojem se vrši odvajanje vezane vode od nafte. Definirani su procesni zahtjevi za automatsko upravljanje pumpama u cilju stabilizacije tlaka u otpremnom slanovodu. Navedena je procesna periferija koja se koristi, te prikazana na dijagramu cjevovoda i instrumentacije (P&ID). Izrađeni su regulatori za PLC Mitsubishi MELSEC iQ-R serije, kojima je zadaća kontrolirati razinu vode u dehidratoru i spremniku slane vode upravljanjem pumpama na njihovim izlazima. Ostvareno je vizualizacijsko sucelje (HMI) s kojeg je moguće zadavati referentne vrijednosti, nadzirati procesne veličine, pratiti trendove i podešavati parametre regulatora. Opisane su sigurnosne funkcije za zaštitu proizvodnog procesa.In this thesis, the technological process is considered and the principle of operation of the plant with a dehydrator and a salt water tank is described. Process requirements are defined for automatic control of pumps in order to stabilize the pressure in the discharging saline. The process peripherals used are listed and shown on the pipeline and instrumentation (P&ID) diagram. Controllers have been made for the Mitsubishi MELSEC iQ-R series PLC, whose task is to control the water level in the dehydrator and salt water tank by controlling the pumps at their outlets. A visualization interface (HMI) has been created from which it is possible to set reference values, monitor process values, monitor trends and adjust controller parameters. Finally, safety functions for the protection of the production process are describe