Person: Alegría Cía, Patricia
Loading...
Email Address
person.page.identifierURI
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
Alegría Cía
First Name
Patricia
person.page.departamento
Ingeniería
person.page.instituteName
ISC. Institute of Smart Cities
ORCID
0000-0003-1174-2037
person.page.upna
811965
Name
3 results
Search Results
Now showing 1 - 3 of 3
Publication Open Access Thermoelectric generator for high temperature geothermal anomalies: experimental development and field operation(Elsevier, 2023) Alegría Cía, Patricia; Catalán Ros, Leyre; Araiz Vega, Miguel; Casi Satrústegui, Álvaro; Astrain Ulibarrena, David; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaIn the current climate and energy context, it is important to develop technologies that permit increase the use of renewable sources such as geothermal energy. Enhancing the use of this renewable source is particularly important in some places, due to its availability and the enormous dependence on fossil fuels, as is the case of the Canary Islands. This work proposes the use of thermoelectric generators with heat exchangers working by phase change to transform the heat from the shallow high temperature geothermal anomalies on the island of Lanzarote directly into electricity, since the use of conventional geothermal power plants would not be possible because they would damage the protected environment. To bring this proposal to reality, this work has succeeded in developing and field-installing a geothermal thermoelectric generator that operates without moving parts thanks to its phase-change heat exchangers. This robust generator do not require maintenance nor auxiliary consumption, and produces a minimal environmental impact, it is noiseless, and the use of water as working fluid makes it completely harmless. The developed device consists of a thermosyphon as hot side heat exchanger, thermoelectric modules and cold side heat exchangers also based in phase change. Tests were carried out in the laboratory at various heat source temperatures and varying the number of thermoelectric modules. It was determined that installing more modules decreases the efficiency per module (from 4.83% with 4 modules to 4.59% with 8 modules at a temperature difference between sources of 235 °C), but for the number of modules tested the total power increases, so the field installation was carried out with 8 modules. After the good results in the laboratory, it was satisfactorily installed at Timanfaya National Park (Lanzarote, Spain) in a borehole with gases at 465 °C. This generator presents a maximum output power of 36 W (4.5 W per module), and is generating 286.94 kWh per year, demonstrating the great potential of the developed thermoelectric generators to build a larger-scale renewable installation.Publication Embargo Diseño, análisis y optimización de un generador termoeléctrico mediante calor geotérmico de origen volcánico(2020) Alegría Cía, Patricia; Astrain Ulibarrena, David; Araiz Vega, Miguel; Escuela Técnica Superior de Ingeniería Industrial, Informática y de Telecomunicación; Industria, Informatika eta Telekomunikazio Ingeniaritzako Goi Mailako Eskola TeknikoaFrente al actual problema energético al que nos enfrentamos, la termoelectricidad aplicada a la energía geotérmica tiene un gran potencial de futuro. Esta tecnología conlleva grandes ventajas como, entre otras, su robustez, fiabilidad, no necesita mantenimiento ya que es una tecnología sin partes móviles, ausencia de ruidos, y es una energía totalmente renovable y limpia. Sin embargo, la eficiencia de un generador termoeléctrico depende en gran medida de los intercambiadores de calor. Por ello es de gran importancia que estos sean lo más eficientes posible. El objetivo de este proyecto es diseñar y estudiar un prototipo de generador termoeléctrico que sea capaz de transformar en electricidad un gradiente de temperaturas entre el ambiente y el calor del suelo del Parque Nacional de Timanfaya. Para ello, se han diseñado y construido intercambiadores de calor específicamente para esta aplicación. La función de estos intercambiadores será transportar el calor con la máxima eficiencia posible desde el interior del sondeo (foco caliente) hasta los módulos termoeléctricos, utilizando una parte de este calor para generar electricidad y otra parte para disiparlo al medio ambiente a través de intercambiadores en el lado frío. El principio de funcionamiento de todos estos intercambiadores será el intercambio de calor por termosifón y cambio de fase. Para lograr el diseño completo, se propusieron y valoraron diferentes soluciones para las diferentes partes que componen el prototipo. Finalmente, se realizó un estudio económico.Publication Open Access Advanced phase-change intermediate heat exchanger development for multistage thermoelectric heat pumps(Elsevier, 2023) Erro Iturralde, Irantzu; Aranguren Garacochea, Patricia; Alegría Cía, Patricia; Rodríguez García, Antonio; Astrain Ulibarrena, David; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaThe need to reach a full energy decarbonisation is well known. Heating and cooling consumption is almost half of the global energy end-use. Thus, development of low-carbon and highly efficient power-to-heat technologies must be developed. In this work, the use of thermoelectric technology working as a heat pump is proposed to heat up an airflow of 38 m3/h. Two different prototypes of multistage thermoelectric heat pumps have been developed and compared based on monophasic and phase-change intermediate heat exchangers. The reduced thermal resistance obtained for the novel phase-change heat exchanger increases the heat flux supplied to the airflow and reduces the consumed power of the system, outperforming the operation of the monophasic thermoelectric heat pump between a 30 and a 67 %. The novel multistage phase-change heat pump obtains experimental COP values between 3.25 and 1.26 when the airflow rises its temperature from 3.5 °C to 23.5 °C. Additionally, this experimental study proves a new methodology to calculate the supplied heat flux to the airflow. The validation of this technology proves a discrepancy of ± 9 % when this novel technology is compared to the conventional one based on the airflow temperature rise.