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Learner taskswith info mapping
mappingtext
writingfrommaps
summarizing controllingnavigation
Learner taskswith info mapping
mappingtext
writingfrommaps
summarizing controllingnavigation
Learner taskswith info mapping
mappingtext
writingfrommaps
summarizing controllingnavigation
in mapping tasks,limit the number
of nodes
this forces learnersto identify
main structures
Ocean thermal energy could be the wave of the futureNoriyuki Yoshida The Daily Yomiuri 01 01 23
__________________________________________________________________________________________________________________________________________________________The experiment uses technology developed by Prof. Haruo Uehara and researchers at the science and engineering department of Saga University. It is hoped that the test will produce 1,000 kilowatts of electricity, and it is expected that the technology will provide cost-efficient, environmentally friendly energy in the 21st century.__________________________________________________________________________________________________________________________________________________________Thermal and nuclear power plants boil water into steam, which rotates turbines to generate electricity. The basic mechanism of the OTEC is the same, but instead of water, the OTEC process uses ammonia, which is more energy efficient because it evaporates at a much lower temperature than water.
__________________________________________________________________________________________________________________________________________________________ First, liquid ammonia is heated with water of 20 C to 30 C drawn from near the surface of the Indian Ocean and converted into steam. Then the ammonia steam rotates turbines and generates electricity. Finally the steam is cooled with 6 C deep-sea water and converted back to liquid.
__________________________________________________________________________________________________________________________________________________________In thermal power generators, the temperature difference between water and steam is about 500 C, which means the steam is packed with energy. But the temperature difference in the OTEC system is only about 20 C, so the energy from the ammonia steam is relatively low. To overcome this, OTEC utilizes a process developed by Uehara to improve the heating and cooling of the ammonia and use water as a solvent.
__________________________________________________________________________________________________________________________________________________________The OTEC system's heat efficiency rate (the percentage of generated power compared to the total energy poured into the system) has reached a high of 5.2 percent under the Uehara Cycle. This is much lower than 40-percent level in thermal power generation and the 50 to 60 percent efficiency of power generation using a combination of thermal systems and gas.
__________________________________________________________________________________________________________________________________________________________Uehara said, "Because the source of heat is seawater, the energy cost is zero. The overall costs of the power generation processes are not much higher than those of thermal generation and other forms," he said.
e.g.Take a tech article,
remove topic and conclusion sentences from each paragraph,
have learners map the article with 15 nodes or fewer.
Use the infomap links to map the text.
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Description Classification
Degreecomparison
Attributecomparison
Sequence Cause-effect
Contrast
!
Generalprocess:
boilNH3
Makesteam
Rotateturbines
Generateelectricity
Boil aliquid
older typeplants
OTECplants
boilH2O
seawaterheat
fossil orN-heat
steam20C
steam500C
lowpower
highpower
zeroenergy cost
highenergy cost
hunter systems
!
!
!
Steam-based power generating systems
Generalprocess:
boilNH3
Makesteam
Rotateturbines
Generateelectricity
Boil aliquid
older typeplants
OTECplants
boilH2O
seawaterheat
fossil orN-heat
steam20C
steam500C
lowpower
highpower
zeroenergy cost
highenergy cost
hunter systems
!
!
!
Steam-based power generating systems
Steam-based power generating systems
Generalprocess:
hunter systems
Makesteam
Rotateturbines
Generateelectricity
Boil aliquid
boilH2O
seawaterheat
fossil orN-heat
steam20C
steam500C
lowpower
highpower
zeroenergy cost
highenergy cost
older typeplants
OTECplants
Steamplants
boilNH3
Steam-based power generating systems
boilH2O
seawaterheat
fossil orN-heatsteam
20Csteam500C
lowpower
highpower
zeroenergy cost
highenergy cost
older typeplants
OTECplants
Steamplants
boilNH3
Steam-based power generating systems
