8 research outputs found
Applying homotopy perturbation method to provide an analytical solution for Newtonian fluid flow on a porous flat plate
This research work is going to apply the homotopy perturbation method to solve the problem of flowing Newtonian fluid on a flat plate. For this purpose, initially, the problem, including the governing equations and boundary conditions, is defined, and after that, the considered assumptions to solve the defined problem are introduced. Next, the working principle of the homotopy perturbation method is described, and then, the way to obtain the analytical solution using the homotopy perturbation method is presented, and finally, the accuracy of the proposed analytical solution in comparison to the numerical approach is compared for validation. Both momentum and energy equations are solved. The maple software program is utilized for carrying out the mathematical calculations, while the validation is done using the profiles for stream function, velocity distribution, stress, and dimensionless temperature as the key indicators related to the solution. The conducted comparison shows that the analytical solution provided by the homotopy perturbation method is able to predict all the important performance criteria for the problem very well, and therefore, the homotopy perturbation method has a strong potential to be employed for providing the analytical solution for such problems.http://wileyonlinelibrary.com/journal/mma2022-02-05hj2021Mechanical and Aeronautical Engineerin
A Road Map to Detect the Foremost 3E Potential Areas for Installation of PV Façade Technology Using Multi-Criteria Decision Making
A procedure to prioritize the cities to utilize a building integrated photovoltaic thermal (BIPV/T) system is proposed in which the technique for order of preference by similarity to ideal solution (TOPSIS) is employed as a systematic decision-making method. Electricity generation and heat recovery in a year from the energy side, levelized cost of electricity (LCOE), and payback period (PBP) from the economic viewpoint, as well as the carbon dioxide savings from the environmental perspective, are taken into account as the decision criteria. They are the key economic, environmental, and energy (3E) performance indicators of the system. The novelty of the proposed research approach is two items. The first item is systematic and could be employed for each and every case. Moreover, another item is that selection is made based on energy, economic, and environmental (3E) criteria all together, as the important aspects of an energy system. Having introduced the procedure, it is utilized to rank five cities in Iran for the installation of BIPV/T technologies. The cities are Tehran, Tabriz, Yazd, Rasht, and Bandar Abbas, where each one is a populated city from one of the climatic conditions of the country. According to the results, a high priority is seen for two cities: the first city is Yazd with the highest ambient temperature and relative humidity among the alternatives, and the other city is Tehran, with the highest natural gas and electricity tariffs, as well as the greatest price for operating and maintenance. The values of heat recovery, electricity generation, carbon dioxide savings, PBP, and LCOE for Yazd are 42.3 MWh, 23.4 MWh, 16.8 tons, 5.48 years, and 9.45 cents per kWh. The corresponding values for Tehran are 35.6 MWh, 21.6 MWh, 15.0 tons, 2.79 years, and 8.71 cents per kWh, respectively
A Road Map to Detect the Foremost 3E Potential Areas for Installation of PV Façade Technology Using Multi-Criteria Decision Making
A procedure to prioritize the cities to utilize a building integrated photovoltaic thermal (BIPV/T) system is proposed in which the technique for order of preference by similarity to ideal solution (TOPSIS) is employed as a systematic decision-making method. Electricity generation and heat recovery in a year from the energy side, levelized cost of electricity (LCOE), and payback period (PBP) from the economic viewpoint, as well as the carbon dioxide savings from the environmental perspective, are taken into account as the decision criteria. They are the key economic, environmental, and energy (3E) performance indicators of the system. The novelty of the proposed research approach is two items. The first item is systematic and could be employed for each and every case. Moreover, another item is that selection is made based on energy, economic, and environmental (3E) criteria all together, as the important aspects of an energy system. Having introduced the procedure, it is utilized to rank five cities in Iran for the installation of BIPV/T technologies. The cities are Tehran, Tabriz, Yazd, Rasht, and Bandar Abbas, where each one is a populated city from one of the climatic conditions of the country. According to the results, a high priority is seen for two cities: the first city is Yazd with the highest ambient temperature and relative humidity among the alternatives, and the other city is Tehran, with the highest natural gas and electricity tariffs, as well as the greatest price for operating and maintenance. The values of heat recovery, electricity generation, carbon dioxide savings, PBP, and LCOE for Yazd are 42.3 MWh, 23.4 MWh, 16.8 tons, 5.48 years, and 9.45 cents per kWh. The corresponding values for Tehran are 35.6 MWh, 21.6 MWh, 15.0 tons, 2.79 years, and 8.71 cents per kWh, respectively
Acquiring an analytical solution and performing a comparative sensitivity analysis for flowing Maxwell upper-convected fluid on a horizontal surface
The problem of flowing a Maxwell upper-convected fluid on a horizontal surface is considered here in two conditions. One is the condition in which the plate is made of a porous material, and another one when it is not. For each case, the analytical solution is found using a technique called homotopy perturbation method (HPM). The codes developed in Maple software program are employed for this purpose, and the profiles for velocity and temperature are obtained. The provided analytical solution for each condition is validated using the numerical simulation of the boundary value problem (BVP), and then, a comprehensive sensitivity analysis is carried out. According to the results, for each case, an excellent agreement between the numerical simulation and analytical solution is seen. Moreover, it is found that the skin friction coefficient has a downward trend for both conditions when Deborah goes up. Furthermore, increasing the porosity coefficient is accompanied by decrease in both drag force and hydraulic boundary layer. In addition, for the investigated conditions, having a higher porosity factor leads to an enhancement in the heat transfer, whereas a decrease in Deborah has the same effect.https://www.sciencedirect.com/journal/thermal-science-and-engineering-progress2022-02-27hj2021Mechanical and Aeronautical Engineerin
Using Building Integrated Photovoltaic Thermal (BIPV/T) Systems to Achieve Net Zero Goal: Current Trends and Future Perspectives
The rising world population and increasing shift toward reducing greenhouse gas (GHG) emissions have highlighted the importance of cleaner and more-efficient technologies such as solar energy harvesting systems. Among these, building integrated photovoltaic (BIPV) and building integrated photovoltaic thermal (BIPV/T) systems are considered to be superior in supplying electrical and thermal demands while also enhancing the attractiveness of the buildings to which they are attached. This chapter introduces this technology and explains its role in achieving both net zero energy buildings (NZEBs) and net zero emission (NZE) targets. First, the BIPV/T concept is introduced, and then the processes of simulating BIPV/T system performance in both free and forced convection conditions are explained. Next, net zero targets are defined, and a number of studies that have tried to help meet net zero goals using BIPV and BIPV/T systems are reviewed. The chapter ends with concluding remarks and suggestions for future work.KeywordsEnergy efficiencyNet zero emissionNet zero energy buildingDesignMulti-objective optimizationBuilding facadeEnvironmental protectionPerformance modelin
Using machine learning in photovoltaics to create smarter and cleaner energy generation systems: a comprehensive review
Photovoltaic (PV) technologies are expected to play an increasingly important role in future energy production. In parallel, machine learning has gained prominence because of a combination of factors such as advances in computational hardware, data collection and storage, and data-driven algorithms. Against this backdrop, we provide a comprehensive review of machine learning techniques applied to PV systems. First, conventional methods for modeling PV systems are introduced from both electrical and thermal perspectives. Then, the application of machine learning to the analysis of PV systems is discussed. We focus on reviewing the use of machine learning algorithms to predict performance and detect faults, and on discussing how machine learning can help humanity to achieve a cleaner environment in the worldwide drive towards carbon neutrality. This review also discusses the challenges to and future directions of using machine learning to analyze PV systems. A key conclusion is that the use of machine learning to analyze PV systems is still in its infancy, with many small-scale PV technologies, such as building integrated photovoltaic thermal systems (BIPV/T), not yet benefiting fully in terms of system efficiency and economic viability. The wider application of machine learning to PV systems could therefore forge a shorter path towards sustainable energy production
Techno-economic evaluation of a hybrid photovoltaic system with hot/cold water storage for poly-generation in a residential building
There is a growing effort towards the application of solar technologies to meet electrical and thermal demand.
However, substantial energy is used in buildings around the world for electricity and thermal comfort. Here we evaluate a novel hybrid solar-powered system for reducing the load on the direct expansion and heat pump unit of a combined heating and air conditioning system while generating electricity. The system combines rooftop photovoltaic (PV) and building-integrated photovoltaic thermal (BIPV/T) systems for electricity generation, while any excess electricity is used to drive a hot and cold water storage system. A residential building in Tehran is used as a case study, and the results are computed via MATLAB, TRNSYS, and Carrier HAP software. The system is shown to outperform both rooftop PV and BIPV/T systems alone, generating at least 50% more electricity
while reducing the heating and cooling loads on the machinery by at least 60%. The system also enjoys a payback time of 2.87 years. The impact of thermal comfort setpoints, in addition to inflation and discount rates, are also evaluated via a sensitivity analysis involving several key performance metrics, namely the hot and cold water storage volumes, the size of the desiccant wheel, and the payback time. The cooling load is found to have the greatest influence on the cold water storage volume and the desiccant size, with 80.1% and 41.2% variations for baseline variations of ±20%. With a 57.7% increase, the heating load is found to have the biggest influence
on the hot water storage volume. With a 27.1% variation, inflation has the strongest effect on the payback time