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The purpose of this study is to examine the effects of inclination angle on the thermal energy storage capability of a phase change material (PCM) within a disc-shaped container. Different container materials are also tested such as plexiglass and aluminium. This study aims to assess the energy storage capacity, melting behaviour and temperature distributions of PCM with a specific melting range (22°C–26°C) for various governing parameters such as inclination angles, aspect ratios (AR) and temperature differences (ΔT) and compare the melting behaviour and energy storage performance of PCM in aluminium containers to those in plexiglass containers.

A finite volume approach was adopted to evaluate the thermal energy storage capability of PCMs. Five inclination angles ranging from 0° to 180° were considered and the energy storage capacity. Also, the melting behaviour of the PCM and temperature distributions of the container with different materials were tested. Two different AR and ΔT values were chosen as parameters to analyse for their effects on the melting performance of the PCM. Conjugate heat transfer problem is solved to see the effects of conduction mode of heat transfer.

The results of the study indicate that as AR decreases, the effect of the inclination angles on the energy storage capacity of the PCM decreases. For lower ΔT, the difference between the maximum and minimum stored energies was 20.88% for AR = 0.20, whereas it was 6.85% for AR = 0.15. Furthermore, under the same conditions, the PCM stored 8.02% more energy in plexiglass containers than in aluminium containers.

This study contributes to the understanding of the influence of inclination angle, container material, AR and ΔT on the thermal energy storage capabilities of PCM in a novel designed container. The findings highlight the importance of AR in mitigating the effect of the inclination angle on energy storage capacity. Additionally, comparing aluminium and plexiglass containers provides insights into the effect of container material on the melting behaviour and energy storage properties of PCM.

In this chapter the potential to use water-based Trombe walls to provide heated water for building applications during the summer months is investigated. Design Builder software is used to model a simple single-story building with a south-facing Trombe wall. The effects of using different thermal storage mediums within the Trombe wall on building heating loads during the winter and building cooling loads during the summer are modeled. The amount of thermal energy stored and temperature of water within the thermal storage medium during hot weather conditions were also simulated. On a sunny day on Toronto, Canada, the average temperature of the water in a Trombe wall integrated into a single-story building can reach ∼57°C, which is high enough to provide for the main hot water usages in buildings. Furthermore, the amount of water heated is three times greater than that required in an average household in Canada. The results from this work suggest that water-based Trombe walls have great potential to enhance the flexibility and utility of Trombe walls by providing heated water for building applications during summer months, without compromising performance during winter months.

This study aims to focus on understanding how different jet angles and Reynolds numbers influence the phase change materials’ (PCMs) melting process and their capacity to store energy. This approach is intended to offer novel insights into enhancing thermal energy storage systems, particularly for applications where heat transfer efficiency and energy storage are critical.

The research involved an experimental and numerical analysis of PCM with a melting temperature range of 22 °C–26°C under various conditions. Three different jet angles (45°, 90° and 135°) and two container angles (45° and 90°) were tested. Additionally, two different Reynolds numbers (2,235 and 4,470) were used to explore the effects of jet outlet velocities on PCM melting behaviour. The study used a circular container and analysed the melting process using the hot air inclined jet impingement (HAIJI) method.

The obtained results showed that the average temperature for the last time step at Ф = 90° and Re = 4,470 is 6.26% higher for Ф = 135° and 14.23% higher for Ф = 90° compared with the 45° jet angle. It is also observed that the jet angle, especially for Ф = 90°, is a much more important factor in energy storage than the Reynolds number. In other words, the jet angle can be used as a passive control parameter for energy storage.

This study offers a novel perspective on the effective storage of waste heat transferred with air, such as exhaust gases. It provides valuable insights into the role of jet inclination angles and Reynolds numbers in optimizing the melting and energy storage performance of PCMs, which can be crucial for enhancing the efficiency of thermal energy storage systems.

The purpose of this study is to find a control method for three-phase four-wire shunt active power filters, which uses a load-equivalent conductance for obtaining a reference signal for compensating non-active current.

Changes of energy stored in an active filter’s reactance elements are monitored to find the active component of the load current. It is then used as a current reference to be realised as a supply source current. Computer simulation methods were used to verify the presented control method.

To calculate the reference signal for the active filter action, it is enough to measure the active filter’s DC-side capacitors’ voltages. It has been proved that P regulators are sufficient to realise compensating current and to stabilise active filter capacitors’ voltages. The supply source-neutral conductor current can be zeroed even for nonlinear and unbalanced load-generating DC-component in its neutral conductor. In addition, the active filter can buffer load-active power changes and act simultaneously as a local energy accumulator.

This paper provides an alternative approach to address the problem of the three-phase four-wire shunt active power filter control methods.

The purpose of this paper is to investigate energy performance of thermal insulation modified by phase change materials (PCM). Special attention was paid to the problem of proper performance assessment of such components by computational techniques and methods of its evaluation.

Analysis was conducted on the basis of the results obtained using the dynamic building simulation technique performed by ESP-r software. Two cases of insulation components enhanced by a layer: characterised by increased latent heat capacity were analysed and compared. Results were investigated in terms of thermal comfort and energy efficiency, using evaluation methods from literature and new, original indicators proposed by authors.

The analysis revealed that performance of insulation enhanced by PCM is very dynamic and highly sensitive to changeable weather conditions. Thus, there is a strong need for the development of the assessment methods and guidelines for the performance of such components with changeable physical properties.

The methodology and the results reported in this paper could be used as a guideline for further parametric studies and optimisation tasks. Further development of phase change insulation can substantially change the existing approach to the building energy performance.

The paper introduces a new approach of the assessment of insulation components modified by PCM and highlights the dynamic characteristics of its performance.

This paper aims to propose an approach based upon the principal component analysis (PCA) to define a contribution rate for each variable and then select the main variables as inputs to a neural network for energy load forecasting in the region southeastern Brazil.

The proposed approach defines a contribution rate of each variable as a weighted sum of the inner product between the variable and each principal component. So, the contribution rate is used for selecting the most important features of 27 variables and 6,815 electricity data for a multilayer perceptron network backpropagation prediction model. Several tests, starting from the most significant variable as input, and adding the next most significant variable and so on, are accomplished to predict energy load (GWh). The Kaiser–Meyer–Olkin and Bartlett sphericity tests were used to verify the overall consistency of the data for factor analysis.

Although energy load forecasting is an area for which databases with tens or hundreds of variables are available, the approach could select only six variables that contribute more than 85% for the model. While the contribution rates of the variables of the plants, plus energy exchange added, have only 14.14% of contribution, the variable the stored energy has a contribution rate of 26.31% being fundamental for the prediction accuracy.

Besides improving the forecasting accuracy and providing a faster predictor, the proposed PCA-based approach for calculating the contribution rate of input variables providing a better understanding of the underlying process that generated the data, which is fundamental to the Brazilian reality due to the accentuated climatic and economic variations.

Bilateral project with Slovenia and Turkey with the title thermal energy storage for efficient utilization of solar energy was the basis for this paper. The paper aims to discuss this issue.

The paper is the review of solar thermal storage technologies with examples of use in Slovenia and Turkey.

The authors have found out that compact and cost effective thermal energy storage are essential.

Research on the field of thermal energy storage in Slovenia and Turkey is presented.

The paper presents solar systems in Slovenia and Turkey.

The paper gives information about the sustainable energy future on the basis of solar energy.

In this study, a solar water heating system along with a seasonal thermal energy storage and a heat pump is designed for a villa with an area of 192 m² in Tehran, the capital of Iran.

According to the material and the area of the residential space, the required heating of the building was calculated manually and then the thermodynamic analysis of the system and simulation was done in MATLAB software. Finally, regarding the waste of system, an efficient solar heating system, providing all the required energy to heat the building, was obtained.

The surface area of the solar collector is equal to 46 m², the capacity of the tank is about 2,850 m³, insulation thickness stands at 55 cm and the coefficient of performance in required heat pump is accounted to about 9.02. Also, according to the assessments, the maximum level of received energy by the collector in this system occurs at a maximum temperature of 68ºC.

To the best of the authors’ knowledge, in the present work, for the first time, using mathematical modeling and analyzing of the first and second laws of thermodynamics, as well as using of computational code in MATLAB software environment, the solar-assisted ground source heat pump system is simulated in a residential unit located in Tehran.

Solar energy varies with time, intermittent; an accumulator unit is required to attach with collectors to collect energy for use when the sunshine is not available. This paper aims to design a system for storing the solar sensible heat thermal energy.

This paper presents the design and experimental evaluation of sensible heat thermal energy storage (TES) system for its energy storage performance by varying the air flow rate and packing material shape. Heat transfer fluid as air and solid concrete material of high density of different shapes were used for storage.

This paper presents the evaluation of data of number of experimental observations on the system. It was found that charging/discharging was based on the shape of the material and void fraction.

This paper provides the data for designing the TES, considering the concrete as storage material and shape of material for optimizing the system.

The purpose of this paper is to optimize the configuration of a heat sink with phase change material for improving the cooling performance of light emitting diodes (LED).

A numerical three-dimensional time-dependent model is developed with COMSOL Multiphysics to simulate the phase change material melting process during both the charging and discharging period.

The model is validated with previously published works. It found a good agreement. The difference between filled cavities with phase change materials (PCM) and alternate cavities air-PCM is discussed. The last-mentioned showed a good ability for reducing the junction temperature during the melting time. Three cases of this configuration having the same total volume of PCM but a different number of cavities are compared. The case of ten fins with five PCM cavities is preferred because it permit a reduction of 21 per cent of the junction temperature with an enhancement ratio of 2:4. The performance of this case under different power input is verified.

The use of alternate air-PCM cavities of the heat sink. The use of PCM in LED to delay the peak temperature in the case of thermal shock (for example, damage of fan) An amount of energy is stored in the LED and it is evacuated to the ambient of the accommodation by the cycle of charging and discharging established (1,765 Joule stored and released each 13 min with 1 LED chip of 5 W).