At the earliest practical time in a project the engineers will need to identify areas of engineering and design where interfaces are necessary. An efficient system of communication and exchange of information should be established and implemented at regular intervals. Meetings should be arranged to discuss problem areas and short-falls in information. The following generally summaries what is needed, particularly during the feasibility and conceptual stage of a project.
In order to be able to engineer an economical and efficient power system it is desirable for the electrical engineer to have:
• A basic understanding of the hydrocarbon and chemical processes and their supporting utilities e.g. compression, pumping, control and operation, cooling arrangements.
• A procedure for regular communication with engineers of other disciplines, e.g. instrument, process, mechanical, safety, telecommunications, facilities, operations and maintenance.
• An appreciation of the technical and economical benefits and shortcomings of the various electrical engineering options that may be available for a particular project.
• The technical flexibility to enable the final design to be kept simple, easy to operate and easy to maintain.
Process Engineers
The process engineers should be able to inform the electrical engineers on matters relating to the production processes and supporting utilities e.g.:
• Oil, gas, condensate and product compositions and rates, and their method of delivery to and from a plant.
• Variation of production rates with time over the anticipated lifetime of the plant.
• Fuel availability, rates and calorific values, pollution components e.g. sulphur, carbon dioxide, alkali contaminants, particle size and filtration.
• Electrical heating and refrigeration loads, trace heating of vessels and piping.
• Make available process flow diagrams, process and instrumentation diagrams, utilities and instrumentation diagrams.
Mechanical Engineers
The mechanical engineers will normally need to advise on power consumption data for rotating machines, e.g. pumps, compressors, fans, conveyors, and cranes. They will also advise the power output options available for the different types and models of prime movers for generators, e.g. gas turbines, diesel engines, gas engines.
In all cases the electrical engineer needs to know the shaft power at the coupling of the electrical machine. He is then able to calculate or check that the electrical power consumption is appropriate for the rating of the motor, or the power output is adequate for the generator.
The mechanical engineer will also advise on the necessary duplication of machinery, e.g. continuous duty, maximum short-time duty, standby duty and out-of-service spare machines. He will also give some advice on the proposed method of operation and control of rotating machines, and this may influence the choice of cooling media, construction materials, types of bearings, ducting systems, sources of fresh air, hazardous area suitability, etc.
The electrical engineer should keep in close ‘contact’ with the progress of machinery selection during the early stages of a project up to the procurement stage in particular, so that he is sure the electrical machines and their associated equipment are correctly specified. Likewise after the purchase orders are placed he should ensure that he receives all the latest manufacturers’ data relating to the electrical aspects, e.g. data sheets, drawings, changes, hazardous area information.
Instrument Engineers
The process and instrument engineers will generally develop the operation and control philosophies for individual equipments and overall schemes. The electrical engineer should then interface to enable the following to be understood:
• Interlocking and controls that affect motor control centres and switchboards, generator controls, control panels, local and remote stations, mimic panels, SCADA, computer networking, displays in the CCR and other locations.
• Cabling specifications and requirements, e.g. screening, numbers of cores, materials, earthing, routing, segregation and racking of cables.
• Power supplies for control systems, AC and DC, UPS requirements, battery systems.
• Symbolic notation, e.g. tag numbers, equipment names and labels, cable and core numbering systems.
Communication and Safety Engineers
The communication and safety engineers will be able to advise on power supply requirements for:
• Radar, radio, telecommunications and public address.
• Aids to navigation, e.g. lamps, beacons, foghorns, sirens; also alarms, lifeboat davits, etc.
• Emergency routing and exit lighting systems.
• Supplies for emergency shut-down systems.
Facilities and Operations Engineers
These engineers do not normally contribute any power consumption data, but their input to the work of the electrical engineer is to advise on subjects such as equipment layout, access to equipment, maintainability, maintenance lay-down space, emergency exit routing, operational philosophies of plant and systems, hazardous area classification.