Energy utilization from deep geothermal sources
Recently, heat extraction from supercritical water (i.e. high pressure and high temperature) has received significant attention. Supercritical water from aquatic reservoirs several kilometers below the surface are led to the surface, and the thermal and pressure energy is converted to electricity in...
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ftntnutrondheimi:oai:ntnuopen.ntnu.no:11250/2558595 2023-05-15T16:51:56+02:00 Energy utilization from deep geothermal sources Ommedal, Daniel Næss, Erling Bordvik, Silje Nord, Lars O. 2018 http://hdl.handle.net/11250/2558595 eng eng NTNU ntnudaim:19179 http://hdl.handle.net/11250/2558595 Energi og miljø Strømningsteknikk Master thesis 2018 ftntnutrondheimi 2019-09-17T06:54:06Z Recently, heat extraction from supercritical water (i.e. high pressure and high temperature) has received significant attention. Supercritical water from aquatic reservoirs several kilometers below the surface are led to the surface, and the thermal and pressure energy is converted to electricity in steam turbines. This technology is presently on the experimental/demonstration stage, but the potential is huge. A case study is conducted to explore the potential for electric power generation from a supercritical geothermal reservoir situated 5 km below the surface with a temperature and pressure of 500℃ and 230 bar, respectively. Evaluations of the fluid composition of deep geothermal wells at the most significant geothermal sites on Iceland, prove that the chemical composition of geothermal fluids highly depends on the geologic condition of the reservoirs. Based on the laws of thermodynamics, a program for calculating temperature, enthalpy and pressure variations during extraction from reservoir to wellhead for high temperature and high pressure geothermal fluids is obtained. Calculations on the case study reveal a pressure drop of 70 bar and a temperature loss of 55℃ during extraction, resulting in a superheated fluid at 459℃ and 160 bar available at the wellhead. The wellhead condition is further analyzed for electric power production by evaluating five power cycle designs. The most efficient design, containing three turbines, two heat exchangers and one throttling valve, resulted in a calculated electrical power output of 38.37 MWe, a total efficiency of 24% and a predicted energy production of 302.5 GWh/year. These results suggest that if the geothermal power cycle for the most efficient design analyzed could be realized with the given assumptions, it would be one of the (if not the) most efficient geothermal power plants worldwide. Master Thesis Iceland NTNU Open Archive (Norwegian University of Science and Technology) |
institution |
Open Polar |
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NTNU Open Archive (Norwegian University of Science and Technology) |
op_collection_id |
ftntnutrondheimi |
language |
English |
topic |
Energi og miljø Strømningsteknikk |
spellingShingle |
Energi og miljø Strømningsteknikk Ommedal, Daniel Energy utilization from deep geothermal sources |
topic_facet |
Energi og miljø Strømningsteknikk |
description |
Recently, heat extraction from supercritical water (i.e. high pressure and high temperature) has received significant attention. Supercritical water from aquatic reservoirs several kilometers below the surface are led to the surface, and the thermal and pressure energy is converted to electricity in steam turbines. This technology is presently on the experimental/demonstration stage, but the potential is huge. A case study is conducted to explore the potential for electric power generation from a supercritical geothermal reservoir situated 5 km below the surface with a temperature and pressure of 500℃ and 230 bar, respectively. Evaluations of the fluid composition of deep geothermal wells at the most significant geothermal sites on Iceland, prove that the chemical composition of geothermal fluids highly depends on the geologic condition of the reservoirs. Based on the laws of thermodynamics, a program for calculating temperature, enthalpy and pressure variations during extraction from reservoir to wellhead for high temperature and high pressure geothermal fluids is obtained. Calculations on the case study reveal a pressure drop of 70 bar and a temperature loss of 55℃ during extraction, resulting in a superheated fluid at 459℃ and 160 bar available at the wellhead. The wellhead condition is further analyzed for electric power production by evaluating five power cycle designs. The most efficient design, containing three turbines, two heat exchangers and one throttling valve, resulted in a calculated electrical power output of 38.37 MWe, a total efficiency of 24% and a predicted energy production of 302.5 GWh/year. These results suggest that if the geothermal power cycle for the most efficient design analyzed could be realized with the given assumptions, it would be one of the (if not the) most efficient geothermal power plants worldwide. |
author2 |
Næss, Erling Bordvik, Silje Nord, Lars O. |
format |
Master Thesis |
author |
Ommedal, Daniel |
author_facet |
Ommedal, Daniel |
author_sort |
Ommedal, Daniel |
title |
Energy utilization from deep geothermal sources |
title_short |
Energy utilization from deep geothermal sources |
title_full |
Energy utilization from deep geothermal sources |
title_fullStr |
Energy utilization from deep geothermal sources |
title_full_unstemmed |
Energy utilization from deep geothermal sources |
title_sort |
energy utilization from deep geothermal sources |
publisher |
NTNU |
publishDate |
2018 |
url |
http://hdl.handle.net/11250/2558595 |
genre |
Iceland |
genre_facet |
Iceland |
op_relation |
ntnudaim:19179 http://hdl.handle.net/11250/2558595 |
_version_ |
1766042060129828864 |