The increasing growth of helium consumption in industries and the limited resources of this element are the challenges that industries will face in the future. One way to reduce the energy ...consumption in producing crude helium is to integrate it with low-temperature cycles. Also, using solar energy as a source of energy production in areas that receive adequate solar energy is an important strategy for energy supply in terms of environmental compatibility and sustainable development. In this paper, a novel integrated structure for producing liquid methanol, liquefied natural gas, and crude helium gas using the process of separating helium from natural gas, methanol synthesis process, organic Rankine cycle, and solar dish collectors is developed and analyzed. This hybrid system produces 3590 kmol h
−1
liquid methanol, 3590 kmol h
−1
liquefied natural gas, and 18.91 kmol h
−1
crude helium. The feed gas extracted from the process of separating helium from natural gas is fed to the steam-natural gas reforming unit, which produces syngas with an amount of 16,015 kmol h
−1
. To supply the input heat to the reforming, solar dish collectors with the climatic conditions of Tehran in Iran are used. The produced syngas along with carbon dioxide is fed into the methanol synthesis unit. The energy and exergy efficiencies of the developed integrated structure are 88.48% and 93.79%, respectively. The exergy analysis of the integrated structure shows that the maximum exergy destruction corresponds to the heat exchangers (56.23%) and reactors (13.83%). The sensitivity analysis illustrates that with an increase in the outlet flow temperature of the methanol reactor from 100 to 200 °C, the energy and exergy efficiencies are increased by 9.939% and 9.257%, respectively. Besides, by increasing the amount of carbon dioxide feeding to the methanol production process from 100 to 1200 kmol h
−1
, the net power consumed and its thermal efficiency are increased by 8.489% and 2.855%, respectively.
With the changes that have taken place in energy-related technologies, the United States has been less affected by the geopolitical risks associated with the supply of fossil fuel energy resources, ...especially crude oil. When the price of oil is low, the geopolitical situation of U.S. energy contrasts with that of other oil-producing countries, which are facing financial pressure due to low oil prices and a high domestic energy demand. Many other countries have been supplying crude oil compared to half a century ago, reducing the strategic importance of major oil exporters, such as key OPEC members in the Persian Gulf. The shale oil revolution in the United States and the transition of energy in countries around the world to more sustainable energy sources, especially renewable energy, have reduced the importance of security in the Arab states of the Persian Gulf for U.S. politicians, which will be intensified in the future. Especially from the middle of the Carter administration period, U.S. politicians saw the security of the Arab states of the Persian Gulf as a prerequisite for securing energy supplies for the U.S. economy, but that has changed. Despite the disruption of Russia’s fossil fuel energy supply, as one of the main energy suppliers, due to sanctions from February 2022, the global energy carriers’ prices are relatively under control. Energy transition is one of the main contributors to lowering the impact of fossil fuel energy supply disruptions on the global economy.
Plate heat exchangers are widely used in various industries. This study considers using a novel design of fractal shape fins with a new structure on the performance of multi-stream plate-fin heat ...exchangers for the first time, which has not been studied by researchers before. The numerical study is done with a 3D finite volume method. The effect of using Oil/MWCNT nanofluid and using various configurations of fractal fins with different attack angles ranging from 30 degrees to 100 degrees with the range of Reynolds number of 10,000–40,000, have been studied in the current research. These changing parameters have a significant impact on the flow field and heat transfer in the heat exchanger. The results of this study show that increasing the angle of attack of fractal fins creates more flow deflection and higher fluid mixing. The rise of the Reynolds number creates stronger vortexes as the flow passes over the fins, thereby it can augment the fluid mixing in the areas which are close to the finned. As the Reynolds number rises, the growth of the thermal boundary layer diminished. It can also be seen that as the fluid impacts the fractal fins at higher angles of attack, the temperature distribution becomes more uniform in the heat exchanger. Increasing the Reynolds number from 10,000 to 40,000 increases the heat transfers up to 63 %. At the constant Reynolds numbers, increasing the fraction of solid nanoparticle volume up to 4 % in the cooling fluid augment the heat transfer rate by 48 % compared to the base fluid. Increasing the fluid velocity results the amplification of longitudinal vortex formation. Therefore, the pressure loss is higher at the increased Reynolds numbers. At the lower Reynolds numbers, the pumping power has a weaker dependency on the nanofluids concentration. Increasing the angle of attack of fractal fins increases the pumping power by 50 % compared with the angle of attack of 30 degrees. Increasing the fractal fin angle of attack compared with 30 degrees increases friction by 45–85 %. Changes in the Colburn factor show that considering all parameters that increase heat transfer, the Colburn factor increases by 23–42 % compared with the base scenario with Re = 10,000 and angle of attack = 30 degrees.
The use of solar trackers can help increase the production and time period of electricity generation in photovoltaic power plants. Different types of trackers in terms of rotation mechanisms and sun ...tracking systems have been used in these types of power plants in recent years. In this article, a comparison has made between the electricity produced of fixed and tracking structures in a number of power plants which are located in different cities of Iran but in similar geographical locations. Following this, software modeling is used to evaluate various sun tracking scenarios in the design of sample power plants. Finally, a techno-economic analysis has been made to evaluate the decision-making regarding the construction of such power plants in Iran using this technology. Using east-west detectors has had a positive effect on increasing the production of power plants, especially in summer. Due to the higher initial costs of using this technology in the power plants, as well as the higher maintenance costs, the economization of the power plants’ business plan is extremely dependent on other economic conditions governing the project. Using trackers alone cannot lead to a better situation in a project’s lifetime. From the national point of view, if domestic companies can produce east-west single-axis tracking technology at an acceptable cost and provide related services in the long term, it would be beneficial for the power grid. One of the attractive proposals for the power plants under construction will be the use of this technology, because of additional electricity production in peak hours in summer. Annual experimental data from different tracking/fixed PV power plant have been used for the first time in this techno-economic investigations, they are validated with the simulation process, and the results have been predicted for a wide range of tracking scenarios. Techno-economic analyses of this type of power plant are an essential need for policy makers and investors in Iran’s energy market.
Thermodynamic and thermoeconomic optimization of a vertical ground source heat pump system has been studied. A model based on the energy and exergy analysis is presented here. An economic model of ...the system is developed according to the
Total Revenue Requirement (
TRR) method. The objective functions based on the thermodynamic and thermoeconomic analysis are developed. The proposed vertical ground source heat pump system including eight decision variables is considered for optimization. An artificial intelligence technique known as evolutionary algorithm (EA) has been utilized as an optimization method. This approach has been applied to minimize either the total levelized cost of the system product or the exergy destruction of the system. Three levels of optimization including thermodynamic single objective, thermoeconomic single objective and multi-objective optimizations are performed. In Multi-objective optimization, both thermodynamic and thermoeconomic objectives are considered, simultaneously. In the case of multi-objective optimization, an example of decision-making process for selection of the final solution from available optimal points on Pareto frontier is presented. The results obtained using the various optimization approaches are compared and discussed. Further, the sensitivity of optimized systems to the interest rate, to the annual number of operating hours and to the electricity cost are studied in detail.
The solvent regeneration in the post-combustion carbon capture process usually relies on steam from the power plant steam cycle. This heat duty is one of the challenges of energy consumption in PCC ...(Post-combustion Carbon Capture). However, this practice results in a significant energy penalty, leading to a substantial reduction in the capacity of the Power Plant, estimated to be between 19.5-40%. This paper investigate the techno-economic feasibility of a solar-assisted regeneration process for the PCC industrial scale with diglycolamine solvent. The study aims to assess the impact of system configuration modifications, such as LVC (Lean Vapor Compression), SPCC (Solar Post-combustion Carbon Capture), and combinations of trough or compound solar collectors with LVC, on energy efficiency and overall plant performance. With 3E analysis for SPCC configuration results show that this configuration. However, reducing energy consumption and energy penalty factor, exhibits a decrease in exergy and exergoeconomic efficiency compared to the other configurations in terms of exergy and exergoeconomic aspects. However, the LVC+SCSS (Solar Combined Separator-Stripper) configuration demonstrates the best performance across the 3E aspects, resulting in a reduction energy penalty to 12.2% and improvements of 38% and 4.2% in exergy and exergoeconomic factors, respectively.
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•Aspen HYSYS v11, empowered by Python, simulates various PCC configurations.•Solar thermal powering PCC yields higher carbon emission reduction.•Compound parabolic collectors outperform parabolic troughs in 3E analysis.•Solar integration boosts plant exergy efficiency by 38%.•Applying LVC+SCSS results in a 9% energy penalty and a 4.2% exergoeconomic factor.
A holistic approach to the management of water, energy, food, and the environment is required to both meet the socioeconomic demands of the future as well as sustainable development of these limited ...resources. The Urmia Lake Basin has faced environmental, social, and economic challenges in recent years, and this situation is likely to worsen under the impacts of climate change. For this study, an adaptability analysis of this region is proposed for the 2040 horizon year. Two models, the water evaluation and planning (WEAP (Stockholm Environmental Institute, Stockholm, Sweden)) and the low emissions analysis platform (LEAP (Stockholm Environmental Institute, Boston, MA, USA)), are integrated to simulate changes in water, energy, food, and the environment over these 20 years. Two climate scenarios and nine policy scenarios are combined to assess sustainable development using a multi-criteria decision analysis (MCDA) approach. Results show that, through pursuing challenging goals in agricultural, potable water, energy, and industrial sectors, sustainable development will be achieved. In this scenario, the Lake Urmia water level will reach its ecological water level in 2040. However, social, technical, and political challenges are considered obstacles to implementing the goals of this scenario. In addition, industry growth and industry structure adjustment have the most impact on sustainable development achievement.
•A model for predicting the greenhouse heating demand is developed and validated.•The potential of greenhouse technology is assessed across different climate zones.•A fuzzy decision-making approach ...is applied to evaluate the energy-saving strategies.•The application of night curtain is ranked first in all climate zones except the coastal dry.•Solar energy storage rock bed is the most sensitive strategy to the climate conditions.
One of the most critical barriers for using a greenhouse is the energy consumption for heating generation, which explains the vital role of energy efficiency. In this study, a model for calculating the heating requirement in greenhouses has been modified and validated by fitting the experimental data. Next, the heating energy requirement and the impact of implementing energy-saving strategies have been investigated through a probabilistic approach for ten climate zones. For this purpose, the heating energy requirement for a conventional greenhouse has been calculated by gathering the climatic data of 225 points. Using the interpolation method and the probability density of actual results, the probability density function (PDF) has been concluded. In each climate zone, the impact of implementing six common strategies for reducing energy consumption have been investigated. In terms of energy-saving effectiveness, the night curtain has the highest average value (ranged from 18% to 28%), and the solar energy storage rock bed has the highest sensitivity (ranged from 12% to 32%). The integrated fuzzy AHP-TOPSIS method is used to rank the energy-saving strategies based on technical, economic, social, and energy criteria. It is concluded that the night curtain is the best energy-saving strategy in most climate zones.
In this study, an integrated hybrid polygeneration system based on solar and biogas energy is developed for simultaneous heat and power generation and hydrogen production. A heat recovery system is ...employed, which can recover the waste heat from the flue gas for effective utilisation in the steam network. The devised system, comprising solar, biogas, chemical, steam, and power islands, is investigated and comparatively evaluated through energy and exergy approaches. Additionally, an optimisation study is carried out to find the optimal exergy efficiency. The findings suggest that integrating the steam island and hybrid system improved the overall system performance significantly. The optimisation results demonstrate the value of 58.06% for exergy efficiency, while energy efficiency is also increased from 60.55% to 65.94%.
•Integration of small MED unit with gas engine power cycle is studied in this paper.•Modeling, simulation, parametric study and sensitivity analysis were performed.•A thermodynamic model for heat ...recovery and power generation of the gas engine has been presented.•Annualized Cost of System (ACS) has been employed for economic assessment.•Economic feasibilty dependence of integrated system on natural gas and water prices has been investigated.
Due to thermal nature of multi-effect desalination (MED), its integration with a suitable power cycle is highly desirable for waste heat recovery. One of the proper power cycle for proposed integration is internal combustion engine (ICE). The exhaust gas heat of ICE is used to produce motive steam for the required heat for the first effect of MED system. Also, the water jacket heat is utilized in a heat exchanger to pre-heat the seawater. This paper studies a thermodynamic model for a tri-generation system composed of ICE integrated with MED. The ICE thermodynamic model has been used in place of different empirical efficiency relations to estimate performance – load curves reasonably. The entire system performance has been coded in MATLAB, and the results of proposed thermodynamic model for the engine have been verified by manufacturer catalogue. By increasing the engine load from 40% to 100%, the water production of MED unit will increase from 4.38 cubic meters per day to 26.78 cubic meters per day and the tri-generation efficiency from 31% to 56%. Economic analyses of the MED unit integrated with ICE was performed based on Annualized Cost of System method. This integration makes the system more economical. It has been determined that in higher market prices for fresh water (more than 7 US$ per cubic meter), the increase in effects number is more significant to the period of return decrement.
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