Thermal Solar Heat Research Articles

Strengths, Weaknesses, Opportunities, and Threats Analysis for the Strengthening of Solar Thermal Energy in Colombia

Colombia has made different efforts to contribute to fulfilling its international commitments to curb climate change by reducing emissions and promoting technological development and project financing. However, the existing policies and regulatory framework primarily focus on promoting the photovoltaic industry for electricity production. Likewise, the energy sector has neglected the potential of solar thermal energy as a heat source. In this sense, it is necessary to redouble efforts through new public policies that integrate solar thermal energy in the residential and productive sectors. Using solar thermal energy for heating can contribute to the energy transition and meet its sustainable development goals. Therefore, the main objective of this work was to analyze Strengths, Weaknesses, Opportunities, and Threats to determine the potential application of thermal solar heat in Colombia while considering the local context. Factors such as their environmental conditions, policies, and regulations; the existence of international agreements; and their political status in general were analyzed. The analysis revealed Colombia’s significant solar heat potential, enabling over 1.3 million cold-climate households to access hot water or reduce firewood use. Industrially, applying solar heat in 5% of the current industry could decrease fossil fuel consumption by 13 PJ. The findings highlight that Colombia’s potential in thermal solar energy necessitates collaborative efforts, legislative reinforcement, climate-adaptive measures, and the resolution of political and social challenges.

Stability Scrutinization of Agrawal Axisymmetric Flow of Nanofluid through a Permeable Moving Disk Due to Renewable Solar Radiation with Smoluchowski Temperature and Maxwell Velocity Slip Boundary Conditions

The utilization of solar energy is essential to all living things since the beginning of time. In addition to being a constant source of energy, solar energy (SE) can also be used to generate heat and electricity. Recent technology enables to convert the solar energy into electricity by using thermal solar heat. Solar energy is perhaps the most easily accessible and plentiful source of sustainable energy. Copper-based nanofluid has been considered as a method to improve solar collector performance by absorbing incoming solar energy directly. The goal of this research is to explore theoretically the Agrawal axisymmetric flow induced by Cu-water nanofluid over a moving permeable disk caused by solar energy. Moreover, the impacts of Maxwell velocity and Smoluchowski temperature slip are incorporated to discuss the fine points of nanofluid flow and characteristics of heat transfer. The primary partial differential equations are transformed to similarity equations by employing similarity variables and then utilizing bvp4c to resolve the set of equations numerically. The current numerical approach can produce double solutions by providing suitable initial guesses. In addition, the results revealed that the impact of solar collector efficiency enhances significantly due to nanoparticle volume fraction. The suction parameter delays the boundary layer separation. Moreover, stability analysis is performed and is found that the upper solution is stable and physically trustworthy while the lower one is unstable.

Design of Earthship for Climate Conditions in Macedonia

The Earthship, as a sustainable nearly zero house, built of natural and recycled materials, represents one of the solutions for the numerous environmental issues. A specific location is chosen by the Lake Ohrid in Macedonia. The house is designed for a single family, with dimensions and materials selected according to recommendations in the literature. It is not connected to the public infrastructural network, reducing its dependence on public services and the use of fossil fuels. It is built of natural and recycled materials, having thermal solar heating and cooling, collection and storage of rain water, controlled wastewater treatment, power from sun or wind and food self-production. Static and dynamic analysis has been performed and stability in this highly seismic region is confirmed, followed by the analysis of the energy efficiency and bill of quantities. This design meets the passive house criteria and the planned investment is considerably lower in comparison to a passive house built of “standard” building materials. The potential benefits of this designed Earthship might have an impact in the future building construction and architecture in Macedonia, especially for suburbs. They might help raise people’s awareness of the benefits of sustainable architecture: reduction of the greenhouse gas emission, saving fresh water reserves by harvesting rainwater and reusing it as grey water, controlling the micro climate of the suburban areas by using energy efficient materials and choosing the right location for building.

Industrial Solar Drying System: Modeling and Design Optimization of Plate Slotted Fin-and-Tube Heat Exchanger

Drying is one of the most energy-intensive stages in clay bricks manufacturing where fuel or another conventional energy source is used to heat the air before blowing it on the wet bricks. In order to reduce the energy consumption and decrease the carbon footprint of construction materials, thermal solar heat represents a promising and suitable energy source for this industrial application. In this paper, the utilization of solar energy in clay bricks drying process through compact cross flow water-to-air heat exchanger is investigated. Considering the intermittent profile of solar radiations, modeling and experimental validation of a water-to-air heat exchanger thermo-flow characteristics estimation at variable hot fluid temperature is performed. An agreement of more than 97% between numerical results and experimental measurements is demonstrated. Additionally, in order to improve the industrial solar drying system efficiency, an optimization of the heat exchanger geometric parameters is carried out based on the performance evaluation criterion and the required drying temperature in clay bricks manufacturing. According to findings, the recommended configuration for a constant heat transfer volume of 0.05m3 is characterized by tube diameter, longitudinal and transverse pitches of 18 mm, fin spacing of 2.9 mm and fin thickness of 0.6 mm. This configuration is able to increase the heat exchanger performance evaluation criterion by around 53% compared to the baseline configuration. The annual thermal performance of the solar dryer is evaluated via dynamic simulation via the TRNSYS software and shows that the optimal configuration improves the drying temperature by more than 16%.

Synthesis of Pt/mesoporous SiC-15 and its catalytic performance for sulfuric acid decomposition

Sulfuric acid (SA) decomposition is one of the key reactions in the sulfur-iodine (SI) cycle to produce hydrogen. Catalysts for the SA decomposition should be active and stable in a wide temperature range of 550–850°C to absorb latent heat generated from a thermal solar heat or a very high temperature nuclear reactor. Here, mesoporous mSiC-15 is prepared using the SBA-15 template. TEM analysis shows that the morphology of the mSiC-15 has the replica structure of SBA-15. Pt/SBA-15 and Pt/mSiC-15 catalysts are prepared by impregnation and the catalytic activity is examined under the reaction condition of 650–850°C and a GHSV of 76,000mL/gcat/h. The Pt/mSiC-15 catalyst is relatively stable for 50h at 850°C, while the Pt/SBA-15 was severely deactivated. The Pt amounts on the Pt/SBA-15 and Pt/mSiC-15 catalysts decreased from 0.73 and 0.80wt% at initial reaction time to 0.39 and 0.68wt% after 12h reaction, respectively. The Pt loss during the SA reaction is main cause of deactivation, which is caused by the evaporation of Pt oxides under O2 environment produced during the SA decomposition. It is observed that the Pt particles are embedded in porous SiO2 (Pt/mSiO2), which is transformed from Pt/mSiC-15 during the SA decomposition for 6h. The Pt/mSiC-15 was relatively active and stable for the SA decomposition and the Pt loss was minimized by the structural change from Pt/mSiC-15 to Pt/mSiO2 after 6h.

Biodiesel Production by Thermal Solar Heating in a Low Cost Plant Using Waste Cooking Oil

Biodiesel Production by Thermal Solar Heating in a Low Cost Plant Using Waste Cooking Oil

Experimental investigation on the photovoltaic–thermal solar heat pump air-conditioning system on water-heating mode

An experimental study on operation performance of photovoltaic–thermal solar heat pump air-conditioning system was conducted in this paper. The experimental system of photovoltaic–thermal solar heat pump air-conditioning system was set up. The performance parameters such as the evaporation pressure, the condensation pressure and the coefficient of performance (COP) of heat pump air-conditioning system, the water temperature and receiving heat capacity in water heater, the photovoltaic (PV) module temperature and the photovoltaic efficiency were investigated. The experimental results show that the mean photovoltaic efficiency of photovoltaic–thermal (PV/T) solar heat pump air-conditioning system reaches 10.4%, and can improve 23.8% in comparison with that of the conventional photovoltaic module, the mean COP of heat pump air-conditioning system may attain 2.88 and the water temperature in water heater can increase to 42 °C. These results indicate that the photovoltaic–thermal solar heat pump air-conditioning system has better performances and can stably work.