Browsing Institut Politècnic d’Innovació i Recerca en Sostenibilitat (INSPIRES) by Author "Akhmetov, Bakytzhan"
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- ItemOpen AccessA comprehensive review on sub-zero temperature cold thermal energy storage materials, technologies, and applications: State of the art and recent developments(Elsevier, 2021) Yang, Lizhong; Villalobos, Uver; Akhmetov, Bakytzhan; Gil, Antoni; Khor, Jun Onn; Palacios, Anabel; Li, Yongliang; Ding, Yulong; Cabeza, Luisa F.; Tan, Wooi Leong; Romagnoli, AlessandroThe energy industry needs to take action against climate change by improving efficiency and increasing the share of renewable sources in the energy mix. On top of that, refrigeration, air-conditioning, and heat pump equipment account for 25-30% of the global electricity consumption and will increase dramatically in the next decades. However, some waste cold energy sources have not been fully used. These challenges triggered an interest in developing the concept of cold thermal energy storage, which can be used to recover the waste cold energy, enhance the performance of refrigeration systems, and improve renewable energy integration. This paper comprehensively reviews the research activities about cold thermal energy storage technologies at sub-zero temperatures (from around 270 ◦C to below 0 ◦C). A wide range of existing and potential storage materials are tabulated with their properties. Numerical and experimental work conducted for different storage types is systematically summarized. Current and potential applications of cold thermal energy storage are analyzed with their suitable materials and compatible storage types. Selection criteria of materials and storage types are also presented. This review aims to provide a quick reference for researchers and industry experts in designing cold thermal energy systems. Moreover, by identifying the research gaps where further efforts are needed, the review also outlines the progress and potential development directions of cold thermal energy storage technologies.
- ItemEmbargoBayesian optimization for effective thermal conductivity measurement of thermal energy storage: An experimental and numerical approach(Elsevier, 2022) Yang, Lizhong; Gil, Antoni; Leong, Pammy S.H.; Khor, Jun Onn; Akhmetov, Bakytzhan; Tan, Wooi Leong; Rajoo, Srithar; Cabeza, Luisa F.; Romagnoli, AlessandroThe increasing demand for cooling and refrigeration poses an urgent need in designing efficient and low-cost thermal energy storage systems for future energy systems. While multiple effects may affect the heat transfer behaviors during thermal energy storage, these effects can be lumped into one parameter, the effective thermal conductivity. Effective thermal conductivity provides a simple and reliable solution for accurate numerical simulations in designing a thermal energy storage system. In this study, a novel experimental, numerical and Bayesian optimization-based method is developed and validated that allows for fast and accurate measurement of the effective thermal conductivities over a wide temperature range. The method can also be applied to other bulky and heterogeneous structures that cannot be considered as continuous media. An experimental setup and a 3D numerical model were developed for the plate-type thermal energy storage. After a thorough algorithm comparison, Bayesian optimization using Gaussian process was selected to search for the effective thermal conductivities with high accuracy (root mean square error < 2 K and R-squared between 0.975 and 0.992). The effective thermal conductivities measured using deionized water as the phase change material were validated by a COMSOL simulation. With the accurate effective thermal conductivity results, we revealed that neglecting the effective thermal conductivity for the solid phase while still using conduction models will lead to significant errors in the simulation. A duo arch-shaped graphite sheet-based macrofiller is designed and inserted into the plate-type thermal energy storage, which increased the effective thermal conductivities by around 20% and suppressed the subcooling effect.
- ItemOpen AccessShell-and-tube latent heat thermal energy storage design methodology with material selection, storage performance evaluation, and cost minimization(MDPI, 2021) Yang, Lizhong; Xu, Haoxin; Cola, Fabrizio; Akhmetov, Bakytzhan; Gil, Antoni; Cabeza, Luisa F.; Romagnoli, AlessandroShell-and-tube latent heat thermal energy storage units employ phase change materials to store and release heat at a nearly constant temperature, deliver high effectiveness of heat transfer, as well as high charging/discharging power. Even though many studies have investigated the material formulation, heat transfer through simulation, and experimental studies, there is limited research dedicated to the storage unit design methodology. This study proposes a comprehensive methodology that includes the material assessment with multi-attribute decision-making and multi-objective decision-making tools, epsilon-NTU method, and cost minimization using Genetic Algorithm. The methodology is validated by a series of experimental results, and implemented in the optimization of a storage unit for solar absorption chiller application. A unit cost of as low as USD 8396 per unit is reported with a power of 1.42 kW. The methodology proves to be an efficient, reliable, and systematic tool to fulfill the preliminary design of shell-and-tube LHTES before the computational fluid dynamics or detailed experimental studies are engaged.