https://hfe.irost.ir/ Hydrogen, Fuel Cell & Energy Storage en daily 1 Sat, 03 Jan 2026 00:00:00 +0330 Sat, 03 Jan 2026 00:00:00 +0330 https://hfe.irost.ir/article_1542.html Energy storage systems have been considered in the last few years to improve the performance of energy grids. In a typical power system, an instantaneous balance between generated and consumed power must be maintained, without storing energy. As a result, the power generation must follow the load curve, and due to the variability of electrical demand, the operation of the energy grid may not be economically efficient. Balancing total generated power with total demand, while accounting for losses, requires optimal performance of the electric power system. Consequently, one of the critical components in any energy network is its ability to regulate load frequency effectively. This study investigates the effect of an energy storage system on enhancing load frequency regulation performance in an interconnected energy network comprising two-area steam and hydropower plants. Initially, the energy grid model, incorporating a superconducting magnetic energy storage (SMES) unit, is expressed in state space using first-order differential equations. Subsequently, the effect of the energy storage system on the power network is explored through system mode analysis. Results from time-domain simulations conducted in MATLAB demonstrate the effectiveness of the system mode investigation and its responsiveness to load fluctuations, confirming the reliability of the approach. https://hfe.irost.ir/article_1546.html The performance of polymer electrolyte membrane (PEM) fuel cells is heavily influenced by the design of the gas flow field, especially on the cathode side. An effective flow field configuration ensures optimal reactant gas distribution, uniform current density, efficient water and heat management, and improved overall fuel cell efficiency. A novel honeycomb flow field design featuring hexagonal pins, as opposed to traditional channel-based designs, demonstrates potential for enhancing fuel cell performance. The dimensions of the pins and the channels housing them are crucial design factors in this novel approach. This study presents a three-dimensional model that numerically solves the equations of continuity, momentum, energy, charge conservation, and electrochemical kinetics across different regions of the fuel cell using a single-domain methodology. The investigation focuses on how variations in the dimensions of the channels and pins within the honeycomb flow field influence the overall performance of the fuel cell. Key design objectives include achieving uniform distribution of reactant gases and current density, enhancing voltage and power density, and minimizing pressure drop. The findings reveal that in a fuel cell equipped with a honeycomb flow field, the velocity within the pin region is significantly higher, leading to improved oxygen transport to the catalyst layer. The strategic arrangement and dimensions of the pins contribute to a more uniform distribution of oxygen and power density. While this innovative flow field design increases cell voltage and power density, it also results in a higher pressure drop compared to conventional parallel-channel configurations. https://hfe.irost.ir/article_1613.html A radiator is a crucial component of an engine's cooling system. It circulates a mixture of water and antifreeze, releasing heat as it draws in cooler air before the fluid returns to the engine. One common issue concerning radiators is their mounting location, which can vary across different automobile models.In automobiles and trucks, the radiator is typically mounted at the front, making it highly susceptible to damage in front-end collisions. Such damage often leads to coolant leakage, which can result in further impairment of the vehicle's engine and cooling system. This report aims to introduce a new system, utilizing a shell-and-tube heat exchanger, as an alternative to the conventional radiator while fulfilling its cooling function. The proposed approach addresses the limitations of traditional radiators and offers improvements in both thermal capacity and safety. This study presents a low-error simulation of the OM457-946 diesel engine, manufactured by IDEM Tabriz Company, incorporating both a test report and an accurate performance curve. The heat load values are 65.31 kW at no-load and 900 rpm, and 120.95 kW at full engine load and 2000 rpm. The engine's power output and thermal efficiency were analyzed at various speeds, revealing that replacing the shell-and-tube heat exchanger with an automotive radiator increases the cooling system's volume and resistance. This modification results in a 2% increase in engine power and a 7% improvement in thermal efficiency. https://hfe.irost.ir/article_1654.html In modern power systems, load dynamics are always dynamic and constantly changing. To maintain the balance between generation and consumption demand during load fluctuations, power systems must operate intelligently and flexibly. Given the lack of sufficient conventional energy sources, it is essential to combine conventional energy sources with renewable energy sources to balance production-consumption. The integration of renewable power production units with intermittent character will cause the uncertainty of active power generation and the mismatch among the generated energy and the required load causes oscillations in the voltage and frequency of the network. Using the load frequency controller (LFC) to adjust the frequency and the automatic voltage regulator (AVR) to control voltage -- through the coordinated management of active and reactive power -- is crucial for enhancing power-system stability, especially in the face of sudden changes in energy demand. In this study, the combined LFC-AVR model is considered for a single-area energy grid, which includes a thermal unit and a hydro plant. Synchronous generators with LFC and AVR are important in providing high-quality and uninterrupted electrical power to the network. The primary purpose of investigation and analysis is to show the influence of coupling AVR and LFC loop simultaneously to regulate voltage and frequency. To improve the system response, an integral controller is used in the LFC loop and a proportional-integral (PI) regulator is employed in the AVR loop. The analysis and simulation results show the reduction of frequency and voltage oscillation due to disturbance in the power system. https://hfe.irost.ir/article_1581.html In this study, a SEPIC converter featuring a novel lossless snubber circuit is proposed for fuel cell applications. In the proposed topology, the main switch turns on under Zero-Current Switching (ZCS) conditions and turns off under Zero-Voltage Switching (ZVS), while all diodes experience Zero-Current turn-off, thereby eliminating reverse recovery issues. Moreover, the energy stored in the snubber circuit is transferred to the output, ensuring that the snubber does not introduce significant power loss to the system. The proposed snubber not only enables soft-switching operation but also enhances the voltage gain of the converter through the use of a three-winding transformer. Additionally, the absence of an auxiliary switch simplifies the control circuitry considerably. The converter has been implemented with a rated power of 200 W, and experimental results confirm the accuracy of both the PSPICE simulations and the theoretical analysis. Low input current ripple, high efficiency of 96.5%, and a switching frequency of 100 kHz make this converter highly suitable for fuel cell energy systems. https://hfe.irost.ir/article_1617.html The research presents a new power generation system which combines geothermal power with solar capabilities, providing a sustainable and efficient energy production solution. The system relies on an evacuated tube collector (ETC) to heat geothermal fluid before it is used in various subsystems. Raising the temperature is crucial for enhancing the operational efficiency of various subsystems within the system. The multigeneration setup consists of five coordinated units, including an ORC electricity generator that produces power while also supplying energy for two subsystems: double-effect absorption cooling and domestic thermal heating to meet energy demand. The integrated system operates PEM electrolyzers alongside hydrogen production and operates reverse osmosis units to generate freshwater through desalination process. The study results indicate that increasing the solar energy received by the collector significantly enhances the overall system performance. As solar energy increases, both the power output and the collector outlet temperature improve. The system’s performance efficiency directly depends on outlet collector temperature, which affects both hydrogen and freshwater production rates. Raising the solar radiation intensity makes the ETC produce more energy and exergy, leading to enhanced overall system operation. Among the tested working fluids, R600 exhibits the best performance, producing 55.16 kg/day of hydrogen and delivering 1.451 kg/s of freshwater -- outperforming other fluids in both categories. https://hfe.irost.ir/article_1487.html In this paper, a power, refrigeration, and hydrogen production cycle using geothermal energy in a binary flash cycle has been conducted from a thermodynamic perspective. The cycle involves a basic condensation refrigeration cycle combined with a binary flash cycle and PEM electrolyzer, with geothermal energy as the driving force. A thorough thermodynamic simulation was carried out using EES software, and a parametric study of the proposed cycle was performed to demonstrate its operability under various input parameters. The results show that TEG 2 and the compressor exhibit the highest exergy destruction rates based on the exergy destruction rate analysis. Moreover, increasing the temperature of the first flash tank results in higher power and hydrogen production rates. Furthermore, increasing the temperature of the second flash tank leads to decreased energy and exergy efficiencies, power, and hydrogen production rates. Also, an increase in the geothermal mass flow rate causes a decrease in the power and hydrogen production rates of the system. Finally, it is found that a higher temperature difference results in a decrease in the hydrogen production rate. https://hfe.irost.ir/article_1551.html Understanding and projecting lithium pricing fluctuations will become increasingly important as the world shifts toward cleaner energy sources and electric mobility. Accurate prediction of lithium prices using accessible and reliable methods is essential for sustainable lithium extraction practices. This study employs machine learning (ML) techniques to forecast the costs of future lithium production, with an emphasis on the relationship between the supply of lithium, the use of EVs, and the renewable energy. To find the most precise approach, five ML models are investigated: K-Nearest Neighbors (KNN), Support Vector Classifier (SVC), Linear Support Vector Regression (SVR), Linear Regression, and Multi-Layer Perceptron (MLP) Regression. KNN emerges as the top performer among them, exhibiting robust prediction capabilities, and it is used as the applied ML model in this work. Eight likely scenarios that could affect lithium prices in the upcoming years are examined. These scenarios include advances in lithium extraction technology, alterations to EV usage patterns, and rising demands for the production of renewable energy. Results reveal that the ML model forecasts a notable upward trend in lithium prices. After 2022 to 2029, as the production of EVs and renewable energies increases, lithium prices are projected to rise substantially from USD 20,973/ton to USD 37,745/ton. From 2029 to 2037, with growing demand for batteries, the price is predicted to rise from USD 37,745/ton to USD 40,747/ton. Despite potential short-term fluctuations due to external factors, the model indicates that the long-term trajectory remains upward in lithium prices by 2040. https://hfe.irost.ir/article_1583.html In recent years, the Solar Stirling Thermal Oscillator (SSTO) has emerged as one of the most effective systems for converting solar energy into mechanical and electrical energy, attracting significant interest from researchers. The main challenge in harnessing these oscillators is to ensure the establishment of stable oscillations in their nonlinear dynamics for consistent and reliable performance. The main contribution of this work is the introduction and application of bifurcation theory for the first time to analyze the nonlinear dynamic behavior of the SSTO and to precisely identify the critical points at which stable limit cycles emerge. In this study, by studying the effects of crucial parameters such as power piston mass, stiffness spring of the displacer piston, and the hot source temperature, the critical ranges related to the onset of stable oscillations in the SSTO have been determined. The outcomes demonstrate that bifurcation analysis provides a novel and powerful tool for assessing and optimizing the design of SSTOs, enabling reliable prediction and assurance of stable dynamic performance before practical implementation. This method offers an effective and new pathway for the reliable and cost-efficient design of SSTOs. https://hfe.irost.ir/article_1614.html A new geothermal multisource energy system is assessed in this research upon a comprehensive 4E framework of the Energy, Exergy, Economic, and Environmental aspects. The system integrates numerous technologies for energy conversion and use, which includes an Organic Rankine Cycle (ORC) coupled with a Thermoelectric Generator (TEG), a Single-Effect Absorption Chiller (SEAC), a Proton Exchange Membrane (PEM). A distinct benefit of the system is its use of a TEG instead of the usual condenser, allowing waste heat to be converted into extra electricity via the Seebeck effect, thus enhancing the efficiency of energy conversion without using extra power. The multigeneration system is designed to produce electricity, heating, cooling, hydrogen and freshwater which makes it perfect for regions endowed with geothermal resources and various energy demands. The simulation results demonstrating a comprehensive thermodynamic simulation indicate that the system has 66.42% energy efficiency and 77.12% exergy efficiency. Based upon exergoeconomic analysis, the capital and maintenance expenditure is mainly financed by the turbines and also the geothermal unit, with a scope for improvement on the heat exchangers and condensers. In general, activity environment index of the system 0.03206 corresponds to negligible ecological disturbance, and its exergy sustainability coefficient is 0.0711, which points out the possibility of further enhancement of sustainability. This geothermal setup is poised excellently as an efficient, sustainable and multipurpose energy solution as per results. https://hfe.irost.ir/article_1615.html A new biomass system that produces electricity, provides heat, makes hydrogen and offers freshwater is described and analyzed in this paper. The proposed setup combines a gas turbine, a supercritical CO₂ cycle, a Kalina cycle, a PEM electrolyzer and a multi-effect desalination (MED) unit. The purpose of this method is to allow energy recovery and minimize its environmental effects on the entire system. To assess how the system operates, detailed thermodynamic and exergoeconomic evaluations were completed for several operating scenarios. The results indicate that high efficiencies have been achieved, with hydrogen and freshwater consistently produced and with almost no irreversible losses during production. The specific unit cost of product (SUCP) was determined to be 17.67 $/GJ, showing that operation costs are low when compared to others. Biomass Energy has shown that raising turbine inlet temperature and controlling biomass moisture content permits the system to work more efficiently and recoup more energy. All in all, it turns out that biomass used in integrated systems provides an effective and environmentally friendly way to supply electricity and heat to many applications when a lot of biomass is available. https://hfe.irost.ir/article_1623.html Due to the irregular availability of natural gas, coal has been proposed as an alternative source for the production of synthesis gas in steel plants. This study simulated of a coal gasification unit aimed at producing synthesis gas. The model was initially validated against available reference data, confirming its accuracy. Using Tabas coal as feedstock, and the gasification process was simulated using an entrained-flow gasifier in Aspen Plus software. Sensitivity analysis was conducted on the type of coal, as well as on the water-to-coal and oxygen-to-coal ratios, to identify key factors affecting the process. Key results show that approximately 29 tons per hour of Tabas coal is required to produce 174.6 m³/h of syngas, sufficient for 110 tons per hour of sponge iron production. Process water consumption is around 0.3 times the coal input, with a cooling and quenching water-to-coal ratio of approximately 1.7, much of which is reused. Significantly, additional water is not required for the water-gas shift reaction due to syngas quenching within the gasifier. The study confirmed that both the type of coal used and the ratios of water and oxygen to coal are critical, with high-quality Tabas coal demanding lower amounts of oxygen and water for syngas production compared to lower-grade coals. This research serves as a valuable guide for improving the efficiency and productivity of coal gasification units in the steel industry. Overall, the findings indicate that using coal for synthesis gas production has great potential in meeting energy demands and enhancing steel industry productivity. https://hfe.irost.ir/article_1645.html The current paper provides a thermodynamic, and thermoeconomic analysis of a new multigenerational energy system consisting of the solar thermal energy source and the wind source. This consists of a Brayton cycle driven by a solar tower, a Steam Rankine Cycle (SRC) with feedwater heater and makeup condensate pump, an Organic Rankine Cycle with ejector refrigeration (ORC-ERC), a thermoelectric generator (TEG), a proton exchange membrane (PEM) electrolyzer and a reverse osmosis (RO) desalination plant so that electricity, hydrogen, freshwater, heating, cooling and domestic hot water are produced simultaneously. It has overall annual power output of 38.37 MW, thermal efficiency of 25.22 percent and exergy efficiency of 50.7 percent. The saltwater has a desalting rate of 0.008 kg/s and hydrogen 19.37 kg/s. The greatest exergy losses can be found in the solar collector, compressors and the combustion chamber pointing out to the areas where improvements can be introduced. From Thermoeconomic point of view, gas turbine is deemed to be capital intensive and the solar collector and wind turbine are highly cost effective. Sensitivity studies show that raising the gas turbine inlet temperature and increment of the pressure ratio of the compressor will boost the performance considerably. All in all, the suggested pathway is not only a technically viable and financially beneficial model of clean, diversified energy production with affinities to locations that have plentiful resources of both solar and wind power.