HollySys is able to provide solutions that cover the whole natural gas industry chain, with intellectual property rights, competent functions, and wide service coverage. The approach is made from a client’s perspective to optimise the client’s production operations.
The integrated natural gas solutions monitor and control the pressure, temperature, flow, tightness, and equipment operating statuses pertaining to the different processes in the industry chain. This realises the monitoring, scheduling, and management of the different processes in the natural gas industry chain. After system production kicks-off, operators are able to manage the operations and monitor the system processes from the control centre.
The long-distance natural gas pipeline comprises a first station, sub-transmission station, intermediate compressor station, pigging stations and valve chamber, and cathode protection station. The automation control system for the natural gas pipeline network construction uses a supervisor control and data acquisition system (SCADA). The SCADA system can be used to monitor, schedule, and manage the whole natural gas pipeline from the dispatch control centre, so the stations along the whole pipeline can be either unmanned or controlled and managed with minimum manning. The SCADA system comprises mainly a dispatch control centre, station control system, and data transmission communication system.
The urban natural gas system comprises the urban sluice gate station, urban high-pressure pipeline network, and high-mid pressure regulation station, mid-pressure backbone pipeline network, mid-pressure sub-backbone pipeline network, and courtyard pipeline network. The SCADA system comprises mainly a dispatch control centre, station control system, and data transmission communication system.
Dispatch control centre: Depending on the size of the SCADA system, the main dispatch control centre, back-up dispatch control centre, or regional dispatch control centre can be established to monitor the key high-mid pressure fuel gas pipeline stations and the remote control cut-off valve chambers. At the same time, it can also monitor the mid-pressure pipeline network monitoring points, and complete a series of tasks including the optimisation of pipeline operations, preparing transportation plants, and measurement management.
Station control system (SCS): Based on the pipeline network station distribution, SCS of different sizes shall be placed at sluice gate stations, pressure regulation stations, remote control cut-off valve chambers, and pipeline monitoring points. The SCS is the remote control monitoring station of the SCADA system. They execute commands that come from the main dispatch control centre, and acquisition and processing of station data, provide interlock protection, constant control, and monitoring of the operating status of the different process equipment. Following that, the acquired data and information is uploaded to the main dispatch control centre.
The LNG station receives liquefied natural gas (LNG) from LNG plants and stores them before gasifying them for distribution to users. The LNG station control system has a MACS-SCADA production control platform, including 4 major systems: The equipment management system, manufacturing execution system (MES), operating training system (OTS), and advanced process control (APC). The LNG station’s core technology platform comprises a safety failure-tolerant computer, safety and reliable industrial Ethernet, fieldbus technology, distributed industrial I/O of large scale real-time database. The station control system’s PLC uses LK large PLC, which supports double system hot backup, power source redundancy, Ethernet redundancy, and bus redundancy. The LNG station and the station’s internal 3rd-party equipment generally use the standard MODBUS for communication.
The CNG automobile gas station monitoring system comprises mainly a monitoring computer, programmable logic controller, instrument and transmitter, and communication equipment. The station control system’s PLC uses LK large PLC, which supports double system hot backup, power source redundancy, Ethernet redundancy, and bus redundancy. The CNG station and the station’s 3rd-party equipment generally use the standard MODBUS for communication.
The CNG automobile gas station monitoring system includes: Optimised system, sequence control system, and emergency brake system. The sequence is such that gas is supplied to different steel cylinders from the optimised system control compressor, and also supplied to the gas filling machine from the high-pressure steel cylinder controlled by the sequence control system to improve the efficiency of the gas filling machine. The emergency brake system control rapidly cuts off the gas supplied from the high-pressure steel containers to the gas filling machine. The CNG automobile gas filling station monitoring system completes tasks such as data acquisition, valve control, interlocking protection, and measurement.
The demand for fuel may change with time, but the supply of gas is basically constant. The storage and distribution station’s main role is to buffer the difference between the gas supply and the gas demand, so as to achieve demand-supply equilibrium. The storage and distribution station can be divided into high-pressure storage and distribution station and low-pressure storage and distribution station. During demand troughs, part of the high-pressure pipeline’s high-pressure natural gas is stored in the storage tanks, which will be used to cater to high demand during demand peaks. The low pressure storage and distribution station is used to store low pressure natural gas. The natural gas storage distribution station’s automation control system comprises a monitoring computer, a programmable logic controller, instrument and transmitter, and communication equipment. The programmable logic controller uses the LK series PLC, which supports double system hot backup, power source redundancy, Ethernet redundancy, and bus redundancy. The storage and distribution station and the station’s 3rd-party equipment generally use the standard MODBUS for communication.