ABDELKADER, M. Systémy akumulace odpadního tepla využívající materiály s fázovou přeměnou [online]. Brno: Vysoké učení technické v Brně. Fakulta strojního inženýrství. 2023.

Posudek vedoucího

Čupera, Jan

The bachelor thesis focuses on the topic of waste heat accumulation using phase transformed materials in a mixture of metal powders. Specifically, a mixture of aluminium and tin was chosen. The total length of the thesis is 48 pages and is divided into three parts. The first part focuses on the description of the different methods of heat accumulation and describes the history of this topic. The second part describes the properties of several metals that are possible candidates for heat storage systems. The third part is experimental. It focuses on the fabrication of a samples of an Al-Sn mixture by Cold Isostatic Pressure and subsequent analysis by Scanning Electron Microscopy and Differential Scanning Calorimetry. The student has demonstrated the ability to use a variety of literature sources to produce an undergraduate thesis on the topic and produce a clear list of possible candidates for a mixture capable of storing heat. He independently performed a characterization and organized the measurement results into clear units. I commend the student's independence in creating the text and processing the results. Unfortunately, the student did not understand some issues, especially related to the evaluation of the results of the measurement of the elemental composition of the oxides and what phases are formed during annealing. This misunderstanding is evident in some parts of the experimental section. All things considered, I consider the thesis suitable for defence and award a grade of A.

Posudek oponenta

Řehořek, Lukáš

The thesis titled "Waste Heat Storage Systems Using Phase Change Materials" addresses the possibilities of utilizing phase change materials for waste heat storage. Overall, the thesis demonstrates the potential and presents interesting findings. The literature review section is well-developed and provides a detailed history of the topic. However, I suggest expanding the list of metals suitable for heat storage via phase change up to a melting temperature of 700°C. This enhancement would offer a more comprehensive overview of potential materials for the intended purpose. The formatting of the text is careless and inconsistent. Content-related errors are also evident, including incorrect references to figures and descriptions of different figures than those indicated by numerical references. It is important for the student to carefully check and rectify these shortcomings. The student does not provide information on the samples used for the DSC measurements, and the justification for not measuring the element composition of the Al phase in the system is insufficient. It would be beneficial for the student to include these details and provide an explanation of their significance within the overall context of the thesis. Figures in the thesis vary in size, which further contributes to inconsistent formatting. Moreover, the references to the used literature are provided without any rules or guidelines. I recommend the student adhere to an appropriate citation style. This way, the thesis will be better documented and accessible to readers who seek further information on the cited literature. Overall, it can be concluded that the work is promising but exhibits several errors due to carelessness. Therefore, despite the mentioned shortcomings, I recommend the thesis for defense.

eVSKP id 148713