Handbook of Electrical Engineering For Practitioners in the Oil, Gas ...

ESTIMATION OF PLANT ELECTRICAL LOAD 7This in turn will enable an initial layout of all the facilities and equipment to be proposed. Since this isa new plant and the preliminary data is estimated from process calculations, mechanical calculationsand comparisons with similar plants, it is acceptable to use the following diversity factors, D c = 1.0,D i = 0.5 andD s = 0.1.Tables 1.5, 1.6, 1.7 and 1.8 show the individual loads that are known at the beginning ofthe project.The total power is found to be 12,029 kW. At this stage it is not known whether the plant iscapable of future expansion. The oil and gas geological reservoir may not have a long life expectation,and the number of wells that can be accommodated on the platform may be limited. The 4000 kWof power consumed by the drilling operations may only be required for a short period of time e.g.one year, and thereafter the demand may be much lower.Table 1.7.Subsidiary load schedule for the low voltage emergency switchboardDescription of loadNo. ofunitsNameplateratings ofeach unit(kW)Continuouspowerconsumed(kW)Intermittentpowerconsumed(kW)Standbypowerconsumed(kW)Emergency lighting 1 75 75 0 0Chlorine generator 1 ∗ 30 30 0 0Desalination unit 1 ∗ 75 75 0 0Potable water pumps 1 5 5 0 0Instrument air compressors 1 90 90 0 0Instrument air driers 1 10 10 0 0Living quarters feeder-B(off) 1 ∗ 500 0 0 0Living quarters emergency feeder 1 100 50 50 0Living quarters hot water pumps 1 15 15 0 0Diesel fuel transfer pump 1 5 5 0 0Emergency diesel eng. sump heater 1 3 3 0 0Emergency diesel gen. auxiliaries 1 2 0 0 2Emergency diesel eng. bat. charger 1 1 0 1 0Emergency diesel eng. room fans 2 11 11 0 0Control room fans 2 22 22 0 0Computer UPS supply 1 5 5 0 0Emergency radio supplies 1 10 0 0 10Navigation aids UPS supply 1 10 10 0 0Life boat davit supplies 2 37 0 50 24Life boat diesel heater supplies 2 4 4 4 0Fire pump engine battery chargers 2 22 22 22 0Seawater washdown pump 1 ∗ 37 0 37 0Anti-condensation swbd heaters — 25 25 0 0Anti-condensation motor heaters — 25 10 15 0Portable lighting supplies 1 1 1 0 0Sub-totals for the switchboard 468 179 58Normal running load for the switchboard = (1.0 × 468) + (0.5 × 179) + (0.1 × 58) = 563 kWFor black start delete loads marked ( ∗ )Black start sub-totals for the switchboard = (1.0 × 363) + (0.5 × 142) + (0.1 × 0) = 434 kW