The upgrade of rack for loading light oil products into car tanks at the tankage facility of Odessa Oil Refinery was completed in 2009 on the basis of DeltaV distributed control system. The loading rack consists of four loading islands equipped with 7 loading stations, which allows loading up to 7 tank trucks at a time. The loading of petroleum products into car tanks is managed by the automated loading system (ALS).
ALS is designed to perform loading tasks contained in the consignment notes (waybills) obtained from the automated oil products accounting information system (AIS) “Accounting and Document Flow” based on the 1C Enterprise software package (PC). The process control system (PCS) monitors the loading processes and returns to the AIS the actual value of oil products sold.
PCS manages the process of loading light oil products into car tanks by controlling actuators, while measuring the main parameters of the oil products loaded (weight, volume, and temperature). It shares this information with top-level information systems, and creates the necessary logs for shipments and operating modes. The system directly measures the weight of loaded oil products (using mass flow meters) in accordance with GOST 26976 standard.
The general structure of automated process control system for loading tank trucks at Odessa Oil Refinery is given at
The main functions of the system include:
- Loading management system functions;
- Interface functions of AWS “ALS Operator”;
- Data exchange between the interface and the DeltaV system;
- Data exchange between the interface and AIS 1C Enterprise.
The process control system performs the following functions:
- Signal processing and status display of shutoff and control valve limit switches;
- Signal processing and status display of loading stands and folding ladders position limit switches;
- Signal processing and status display of grounding control devices and overflow alarms;
- Signal processing and status display of pumps;
- Processing of alarms received from equipment and forming emergency stop signals;
- Sending accident alarms to an operator;
- Managing control valves;
- Pumps on and off;
- Managing oil product loading modes in tankers and controlling oil product flow rate during loading;
- Control of access to loading stations and identifying tankers admitted to loading stations;
- Indicating information for calling the driver;
- Indicating the pre-set and current information on the oil product flow rate;
- Indicating information on faults in the system operating modes;
- Diagnosing process equipment, measuring instruments and the condition of communication between the system and monitoring and measuring instruments.
The core of data collection and processing in ACS for loading light oil products is the system implemented based on the DeltaV package. This system is deployed on a workstation. The internal database of tags and software of AWS “ALS Operator” interface with its local database is located on the same computer. The computer itself is connected to the local network of Odessa Oil Refinery, through which it communicates with AIS 1C Enterprise server and the server of “Accounting of Oil Products” (operational accounting system) software package of the Odessa Oil Refinery. The DeltaV system communicates with FloBoos loading controllers via Modbus RTU protocol. FloBoos controllers communicate with IS-RPI remote I/O devices having discrete and analog input and output channels via a 485 interface using Modbus RTU protocol.
The choice of technical means for the implementation of the project is determined by the types of process control systems, software and hardware used at ODESSA REFINERY, which:
- Minimize implementation risks;
- Reduce costs and time for the project implementation;
- Provide a predictable and reliable level of productivity through the use of proven solutions;
- Achieve the required level of accessibility.
In addition, the use of DeltaV system in this project was evoked by the intention to integrate the ALS PCS with PCS of the tankage facility, and subsequently with PCS of the enterprise. The introduction of this system also made it possible to simplify the deployment of additional field equipment in the future.
DeltaV information flow diagram, communication with external systems and field equipment:
The implementation of this project involved the PCS development, installation of DeltaV system equipment (redundant controllers, input/output modules, and network equipment) in the ALS hardware room, configuration of the ALS operator workstation, establishment of equipment networking, creation of DeltaV control system mimic diagrams and development of “ALS Operator Workstation” software that shares data with “Accounting of Oil Products” and “Document Accounting and Flow” software.
The system was implemented at the facility without decommissioning the loading rack with minimal interruptions.