| Author | Paloso, Generoso M. |
| Call Number | AIT Thesis no. ET-91-12 |
| Subject(s) | Geothermal power plants
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of
Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | The vast amount of low temperature geothermal resources poses a great challenge to
develop and rationally exploit their potentials for power generation. The application of organic
Rankine cycles on these resources has broken the barrier and embarked a thrust towards their
practical utilization. The technology, however, is limited to certain thermal threshold below which
the occurence of the resource is still abundant.
The present work offers alternatives to utilize the low enthalpy geothermal resources
more economically. The impetus for developing these alternatives emanates from the concept
of enhancing the availability of the resource. Absorption cycles are introduced to the Rankine
system to boost the heat source temperature on one side and to reduce the heat sink
temperature on the other.
Computer models have been developed to assess the benefits of coupling absorption heat
transformer (AHT) and vapor absorption chiller (VAC) to the organic Rankine cycle. Results
indicate that though the work output per kg of geothermal fluid of the combined cycles is
generally less than that of the conventional ORC, they have the advantage of requiring smaller
components, thus reducing the overall costs of the system. Moreover, their work output per kg
of Rankine fluid is larger than the ORC in the order of 180% for the ORC-VAC and· 150% for
the AHT- ORC.
Among the two alternatives, the AHT- ORC presents a better option from an economic
point of view. Aside from requiring less heat exhanger areas, its required turbine sizes are
significantly less than ORC- VAC as well as the ORC. However, these turbines may be of multistaged type considering the higher pressure and volume ratio. Further analysis on the costs of
different types of turbines, which is not included in the study, would determine their impact on
the overall system costs.
A sidelight of the study was done on evaluating the performance of an absorption
compression refrigeration cascade that utilizes geothermal brine as its heat source. The results
showed that operating the refrigeration cascade at condensing temperature of 5° C could reduce
the compressor size by 60 to 88%. |
| Year | 1991 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Mohanty, B.
|
| Examination Committee(s) | Mora, Jean-Claude ;Bhattacharya, Sribas C.
|
| Scholarship Donor(s) | Deutscher Akademischer Austauschdienst (DAAD)
Government of Germany |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1991 |