temperature and pressure in the svartsengi ... - Orkustofnun

22consumption of the geothermal heat ing plant. Fig . 6 showsthe discharge of wells and drawdown in the Svartsengireservoir from 1976 to 1982.2.7 General temperature conditionsThe general temperature picture of the field is describedby Fig. 7. There is a 300 m layer of warm water systemhaving a temperature of 1I0-60 D C which can be seen frommeasurements of wells which water level Is 15-20 m belowground level. The geotherrnal system between the depths of600 m and 2000 m had a temperature of at least 240°C whenthe undisturbed water level was between 64 and 73 m before1976. In other words the warm water system overlies thegeothermal system at all locations except in the westernpart of the field (Wells SG-2, 3 and 10) where the latteris vented to the atmosphere through fumaroles. There thesubsurface temperature follows the boiling point curve downto ~OO-500 m where a temperature of about 2~OoC is reached.2.8 The power plantThe power plant at Svartsengi is the first geothermal plantof its kind in the world (T horhallsson, 1979). The thingthat makes it unique is that a high temperature brine isused as a heat source for space heating and also for thegeneration of electricity. called co-generation. thusmaking better use of the geothermal energy than isordinary for high-temperature geothermal installations.This plant was constructed in several stages. The geothermalfluid is exploited by using heat exchangers forthe space heating of all the communities in the westernReykjanes peninsula and the international airport atKeflavik (Thorhallsson. 1979). It was first built togenerate 50 MWt (megawatt thermal) and 2 MWe (megawattelectric) for a district heating system. A 75 MWt a nd 6 MWeaddition was later completed. The heat is extracted byflashing the brine in two stages to60 0 c and using the