Using the Analytic Hierarchy Process (AHP) method for selection of phase change materials for solar energy storage applications

Esta investigación tiene como objetivo seleccionar un material de cambio de fase (PCM) que cumplen mejor la solución del almacenamiento de energía térmica entre 200-400 ° C y reducir el costo de producción.
 El uso de métodos multicriterios de toma de decisiones (MCMD) para la evaluación fueron proporcionales implementados como COPRAS-G, TOPSIS y VIKOR. La ponderación de los criterios se realizó por el método AHP (proceso analítico jerárquico) y los métodos de entropía. La correlación de los resultados entre los tres métodos de clasificación ha sido desarrollada por el coeficiente de correlación de Spearman. Los resultados ilustran el mejor y la segundo mejor opción para los tres MCDM fueron NaOH y KNO3. Además, tenía valores de correlación de Spearman entre los métodos excede de 0.714.

Latent Heat Thermal Energy Accumulation Systems (LHTEAS) using Phase Change Materials (PCM) represent enormous opportunities in improving the performance of thermal energy systems. PCM have a high energy density, and these also play a vital role in energy conservation, environment protection, and sustainability. Low and high thermal range LHTEAS have been predominantly designed, analyzed, and optimized. However, no such attempts for the medium thermal range have been made. The sorting and selection of suitable candidate PCM is an uphill task because of the availability of numerous commercially available PCM with distinct thermo-physical properties. The present study aims to explore the selection of PCM using multi-criteria decision methods (MCDM). For this purpose, 91 organic PCM from the literature have been chosen for a medium temperature range of 40–120°C. The present study explored the ranking of PCM, and the findings reveal that the TOPSIS and VIKOR could have high acceptance for sorting PCM. The selection of organic PCM based on the TOPSIS and VIKOR methods are highly reliable and logical, as both produced highly consistent results with a correlation coefficient of 0.992.

Review on Heat Transfer Enhancement of Phase Change Materials (PCMs)

Buildings use more than 40% of the total power consumed in India. Therefore, implementing energy conservation within buildings is of prime concern. Utilization of passive design parameters, such as Phase Change Material (PCM) incorporation, for energy conservation in buildings is thus a lucrative option. Incorporating PCMs within elements result in lowering of heat gain and temperature within the building. A number of simulation and experimental studies on PCM incorporated buildings, have been carried out. The advancements made in last forty years in the field of PCMs and their utilization as Thermal Energy Storage (TES) medium for buildings have been reviewed and presented in this study. This study focusses on PCM incorporation which is sensitive to its properties and climatic parameters of the location. Thus, there is a need of benchmarking the PCM for their application in buildings. Focus is on buildings in tropical hot climatic conditions, where reduction in cooling load is a challenge. This study lays emphasis on selection of appropriate PCMs based on its phase change temperature. Thermal conductivity, specific heat and latent heat are other properties which must be evaluated before PCM selection and implementation within buildings. The study also encompasses different methods of PCM incorporation being implemented across the world and have marked advantages and disadvantages of each followed by their impact in terms of energy savings.

Investigation on the effect of physical parameters of PCMs on the exothermic properties of energy storage units of bilayer tubes

High energy storage density titanium nitride-pentaerythritol solid–solid composite phase change materials for light-thermal-electric conversion

To address the environmental and energy challenges in modern construction, integrating phase change materials (PCMs) into concrete has emerged as a sustainable solution. This literature review critically examines the incorporation of PCMs in concrete, highlighting its potential to transform building energy efficiency and thermal management. The study categorizes PCMs into four main types: organic, inorganic, eutectic, and bio-based, each with distinctive properties and applications. Additionally, this review explores the thermal energy regulation of PCMs in concrete, focusing on integration methods like microencapsulation and vacuum impregnation while maintaining structural integrity. Practical applications demonstrate that PCMs help mitigate temperature fluctuations, enhancing indoor comfort and reducing energy demand. However, despite their energy-saving benefits, the integration of PCMs can negatively affect the mechanical properties of concrete. Empirical evidence from multiple case studies under various climatic conditions further validates the effectiveness of PCM-enhanced concrete in real-world scenarios. In summary, while PCMs can significantly improve thermal efficiency in buildings and reduce energy consumption, it is crucial to balance thermal management performance with mechanical properties through appropriate PCM selection and advanced integration techniques. Future research should focus on enhancing the dispersion, stability, and long-term durability of PCMs in concrete to ensure they maintain their effectiveness without compromising structural integrity. In addition, addressing the fire resistance and environmental stability of PCMs under various conditions will be essential for broader adoption in construction.

One of the main solutions to energy and environmental problems is to offer cooling using renewable energy sources (RES). However, in the utilization of RES, appropriate energy storage systems are required to overcome the intermittency issues of RES. Phase change materials (PCMs) play a vital role in implementing RES in low-temperature cooling applications, and several studies have reported their advantages and limitations. This review article aims to provide a comprehensive evaluation of current studies on PCM selection, applications, advantages, and the scope of further research to effectively utilize RES for cooling applications. We reviewed recent articles related to theoretical, numerical, and experimental studies on PCM-based solar cooling systems, including transport refrigeration, food outlet chilling, and commercial building cooling. A rigorous examination and summarization of the literature provides a comprehensive overview of the PCM's involvement in enhancing the performance of refrigeration systems. Compared to conventional systems, the inclusion of PCH enhances off-time temperature maintenance by more than six times, reduces pulldown time by up to 78%, and results in energy savings of up to 18.5%. Furthermore, PCM allows the refrigerators to work at the required temperature even after sunshine hours with 8–15% less energy consumption and without battery storage. However, further studies using the recently developed PCMs can determine the performance of system components and their potential application in various sectors of the refrigeration industry in the coming years.

Groundwater resources are essential for drinking water, irrigation, and the economy mainly in semiarid environments where rainfall is limited. Currently, unpredictable rainfall due to climate change and pollution on the Earth’s surface directly affects groundwater resources. In this area, most people depend on groundwater resources for irrigation and drinking purposes, and every summer, most of the area depends on groundwater in a semiarid environment. Hence, we selected two popular methods, the analytical hierarchy process (AHP) and multiple influence factor (MIF) methods, which can be applied to map groundwater potential zones. Nine thematic layers, such as land use and land cover (LULC), geomorphology, soil, drainage density, slope, lineament density, elevation, groundwater level, and geology maps, were selected for this study using remote sensing and geographic information system (GIS) techniques. These layers are integrated in ArcGIS 10.5 software with the help of the AHP and MIF methods. The map of the groundwater potential zones in the study area revealed four classes, i.e., poor, moderate, good, and very good, based on the AHP and MF methods. The groundwater potential zone area is 241.50 (ha) Poor, 285.64 (ha) moderate, 408.31 (ha) good, and 92.75 (ha) very good using the AHP method. Similarly, the MIF method revealed that the groundwater potential classes were divided into four classes: 351.29 (ha) poor, 511.18 (ha), moderate, 123.95 (ha) good, and 41.78 (ha) very good. The results were compared to determine which methods are best for planning water and land resource development in specific areas that have basaltic rock and drought conditions. Both groundwater potential zone maps were validated with water yield data. The receiver operating characteristic (ROC) curve and area under the curve (AUC) model results are found to be 0.80 (good) and 0.93 (excellent) using the MIF and AHP methods, respectively; hence, the AHP method is best for delineation of groundwater potential zone maps and groundwater resource planning. The present study’s framework and the results will be valuable for improving the efficiency of irrigation, conserving rainwater and maintaining the ecosystem in India.

This study aims to make the optimal selection of Phase Change Materials (PCM) based on thermal properties and according to industrial application, in addition to publicize the most used methods to facilitate this selection. Although there are several types of PCM, depending on the composition and characteristics they can be used in different applications. The most used characterization methods, throughout their study, are the DSC and the T-history, but new methods that replicate or exceed the expected are still being studied, which contribute to make an adequate material selection and their components. The bibliography and study of these materials has aroused curiosity and over the years new materials and new ways of obtaining them are studied. Also, to improve the environment in which they work, wider applications and those currently used, it is possible to obtain greater energy efficiency. Abstract should summarize the contents of the paper in short terms, i.e. 150–250 words.

Thermal performance analysis and enhancement of the multi-tube latent heat storage (MTLHS) unit

The integration of heat pumps with thermal energy storage (HP-TES) systems is gaining attention as a viable solution for managing peak building demand driven by immense cooling and heating loads. With growing reliance on renewable energy sources, thermal energy storage offers an excellent opportunity to mitigate mismatches in thermal load between energy supply and demand. The use of phase-change material (PCM) TES is especially promising, as PCMs offer significant latent energy storage capacity with smaller temperature glides in smaller volumes compared to other TES technologies. However, challenges arise because current HP-TES architectures can load-shift only cooling or heating, not both, requiring two systems and thus doubling cost, weight, and footprint. Furthermore, current research efforts lack specific tools and techniques to advance integrated systems from concept design to end-user application, focusing on only discharge performance. To address these challenges, this research proposes a dual-mode (heating and cooling) integrated HP-TES system that uses room-temperature PCM-TES as a high-temperature heat source in heating mode and a low-temperature heat sink in cooling mode, thereby reducing temperature lifts and compressor power. Design criteria for PCM-TES heat exchangers were developed, balancing thermal-hydraulic performance with practical constraints such as available building space and weight requirements along with PCM selection considerations such as shipping conditions, moisture exposure, and number of available cycles. A detailed transient model for HP-TES systems was developed to enable rapid annual performance assessments in any US climate zone. Detailed comparisons of HP-TES performance versus a state-of-the-art base heat pump were conducted for all US ASHRAE climate zones. In cooling mode, overall cooling demand reductions in California were around 20%, while Honolulu's tropical climate led to 14% reductions. Heating mode demand reductions were notably higher, especially in very cold-climate regions, ranging from 40% to 65% for Chicago, IL, to Fairbanks, AK, primarily because the new HP-TES system does not require additional backup heating during peak hours. A laboratory-scale HP-TES system was prototyped and tested using a novel test matrix designed to cover a wide range of possible operating modes, e.g., continuous and cyclic heating and cooling modes. Experimental testing showed demand reductions of 0.6%-30% in cooling mode and 40%-60% in heating mode, with the larger reductions observed under more extreme ambient conditions. The experimental data were utilized to validate the transient HP-TES model, which demonstrated excellent agreement in capacity (<4%), power draw (<1%), and compressor suction / discharge conditions. The highest deviations were reported during startup conditions. Finally, a commercialization plan for HP-TES was presented, highlighting key insights on capital expenses and expected location-specific operating cost savings, along with opportunities for California-specific markets. The work presented here provides design guides and procedures to turn such a system from concept to an off-the-shelf product for consumers.

With the rapid development of science and technology, new technology is starting to be used in various fields including education. Education has a very important progress in a nation, because it can optimize individual potential. The educational process in higher education has a big influence on a student's future. However, there are many students who experience difficulties in choosing a college major after graduating from vocational high school (SMK) or senior high school (SMA), because of the complexity in identifying the suitability between interests and study programs. Decision making is a problem that everyone faces, especially in choosing an appropriate college major. There are many factors to consider, and with many options available, the decision-making process can be difficult. To overcome this problem, this research aims to create a decision support system (DSS) using the AHP (Analytical Hierarchy Process) and TOPSIS (Technique For Order By Similarity To Ideal Solution) methods. The AHP method is used to solve complex problems by structuring a hierarchy of criteria and developing weights or priorities. However, when the AHP method is used with many criteria and alternatives, other methods are needed for more effective results. Therefore, a combined method of AHP and TOPSIS was chosen, where AHP focuses on pairwise comparison matrices and consistency analysis, while TOPSIS can measure relative performance and alternative decision making simply and efficiently. The results of research on decision support systems for selecting majors using the AHP and TOPSIS methods show that the application of the combined AHP-TOPSIS method can be used to determine the best alternative in selecting majors by comparing alternatives based on predetermined criteria. In addition, system testing results show that the system functions as expected and meets user needs. With a decision support system for selecting college majors implemented on the website, it can simplify the decision-making process for students and BK teachers in choosing college majors. The results of the calculation of the percentage of system feasibility in blackbox testing show a value of 95.71%, which indicates that this major selection decision support system website can be used.

In this study, it is aimed to examine the studies based on the AHP (Analytic Hierarchy Process) method in the field of education and to present the researcher's perspective on how to use the AHP method in the field of education. Within the scope of this aim, firstly the AHP method was introduced with a sample application and then the results were interpreted. The other aim of the research; studies which based on the AHP methods in the field of education in the last five years have been examined through content analysis. AHP; is one of the “Multiple Criteria Decision Making (MCDC)” methods that can determine the priority or weights among the criteria and alternatives based on comparative judgments. The content analysis conducted within the scope of the research was carried out in the context of eight criteria determined by the researchers. According to the results of the analysis; the AHP method has shown an increasing tendency compared to the years, and usually is used for determining and prioritizing teaching priorities. Especially in Asia Pacific countries, the AHP method is used much more intensive. Another result is that the AHP method is used to make group decisions rather than individual decisions. It has been seen that the research has been done especially with undergraduate students. In addition to these, there are lots of studies with academicians and experts.

Beef is a livestock product that has economic value. The high demand for meat requires farmers to cultivate cows by supplying cattle to meet consumer needs. In terms of selecting beef cattle seeds, independent breeders still do traditionally. During this time farmers still use the trial and error method in choosing the best type of cow even just concerned with the price factor. This will obviously affect the quality of cattle which results in expensive maintenance costs, less than optimal production yields and even death of cows. The purpose of this study was to conduct a study of the application of technology in the selection of the best beef cattle to increase livestock yield, especially for local independent breeders. The technology used is a combination of the Analytical Hierarchy Process (AHP) method and the Multy Factor Evaluation Process (MFEP) Method. Through a combination of methods, researchers analyzed each criterion and alternative related to the selection of the best beef cattle. AHP method was chosen because it has the ability to analyze more consistent criteria. While the selection of the MFEP method is due to having the ability to analyze alternatives based on existing criteria in a simple and accurate way. The results of the AHP and MFEP analysis method are AHP analysis to assist in determining the priority factors of beef cattle seedlings and applied to the MFEP method which produces the highest alternative A6 with a value of 0.508. This research is expected to become a new foundation for farmers in knowing the criteria and alternatives in determining the best type of beef cattle.