Kristin FEED illustrates some of the choices which condition Modularisation

Kristin FEED and Varg had many similarities. This particularly conserns Power Generation. Both saw GT,s as a solution and the

installation of Power Generation on the stern of the relarive Floater. Both use a bow swivel mooring, booth have profiles to accomodate

Bow and Stern Rise. Stern Power Generation requires stability of the hull to allow continuos power generation without interuption because

of movements to upset shaft dynamics. All rotational shafts, GT's Comp[ressors etc require stability for bearing dynamics. these are

monitored by accelerometers, gap measuremnts etc. Both the Kristin FEED and Varg saw this as a solution. Kristin Feed had othe

requirements. Most ot this was the compatabilty of GT's versus Steam Turbines to produce epower the most effectively. Kristin had a

vriable process requirement and the diagrams show the analasys between a steam route verssus a GT route. Atr the time of the FEED

ABB

had introduced a larger style of GT and had established a related heat recovery. The related exercise was to eatablish the optimum. Best Price, Best Production, Best Economic Out Put, Best Operational Case etc etc . This for the kristin FEED was to use ABB GT;s.

In the Diagrams we see Kristin Layout. The elevation and Plan show the stern positioning. The last 2 diagrams illustrate, the selection of

Process Cases and the Heat and Mass Balances related to these. Heat Recovery plays an important part in the arguments for the

economy of Gas Turbines. The need for this is balanced by the cost of supply for extensive inlet and exhaust systems particulary for heat

recovery usually via a steam generation system. The Kristin Study was able to make use of the fact that the available Gas Turbines of low

weight were now in the 40mW Range

Following on we see the establishment of the machine /Driver and the restraints concerning it's postioning. On the stern it is in a less

hazardous postion, away from the Process Area's, its only complication in this respect concerns theFuel Gas Feed, Given the Mass

Balances of Process and its Process Acceptability, its extentof supply must be confirmed. The location of the units on the stern follows the

safety philosophy developed, these are in a similar position as Varg. Being on the stern it is essential for mono hulls that the stern does not

display large movements from the sea state, ie a wave must exit the hull without excessive lift. With items like this it is not the bare machine

but the accessories it must have to enable it to be located in the environmet specified. Gas Turbines do not generally like a saline

atmosphere, this is particularly true for the blading. For this reason elaborate filtration and seperation must be installed for the combustion air

intakes. To assist economic use heat recovery is required for the combustion gas exhaust, silencing and any ingress from sea

water/atmosphere.