kW Of Electric Power Research Articles

Thermodynamic analysis and multi-objective optimization of an ORC-based solar-natural gas driven trigeneration system for a residential area

Regarding the growing demands for energy, depletion of fossil fuel resources, and the adverse environmental consequences associated with their utilization, especially global warming, it is imperative to increase the share of renewable resources within energy systems. During the summer season, the residential sector in Khuzestan province, Iran, experiences a significant surge in energy consumption. This elevated demand is mostly attributed to the region's severe temperatures, requiring the extensive use of cooling equipment. As a result, taking into account the high potential for solar energy in the nation, this research first uses TRNSYS software to calculate the cooling and heating loads of a residential area in the province of Khuzestan. Next, a solar-natural gas Combined Cooling, Heating and Power (CCHP) system is designed and modeled using Engineering Equation Solver (EES) software, with the goal of supplying the cooling load. Then, using the particle swarm optimization technique, the system's multi-objective optimization was completed. The results showed that a fuel consumption rate of 0.04274 kg/s is required in steady state conditions to supply a cooling load of 1446.2 kW for the region with 1000 m2 of solar collecting area. A total of 465.7 kW of electric power and 3336 kW of heating are produced. The system's energy and exergy efficiencies were determined to be 186.6 % and 27.81 %, respectively. Eventually, the findings of this study demonstrated that the proposed configuration has the potential to provide multiple positive outcomes with a high level of efficiency, and improve the share of renewable energy.

Performance evaluation of a novel fuel cell and wind-powered multigeneration system

The introduction of promising energy sources to satisfy human desires is extremely crucial. The present work studies the performance of an original solid oxide fuel cell-wind-based polygeneration system for producing hydrogen, sodium hypochlorite, potable water, heating, cooling, and electrical power. In the methodological concept, energy, exergy, economic, and exergoenvironmental assessments are carried out to evaluate the system performance concerning different parameters. The technical outcomes depict that the system can produce 363 kW of electrical power, 162 kW of cooling, and 46.5 kW of heating at the design operating settings while the energy and exergy efficiencies are 55.5% and 38.1%, respectively. Moreover, over a year of operation, the system can provide 19.9 × 10 4 m3 gaseous hydrogen, 50.9 ×‎ 103 m3 potable water, and 5.31 tonnes of sodium hypochlorite to increase the gained benefits from this efficient and cost-effective system. To evaluate the prevalence of the designed system, the economic outcomes demonstrate that the payback period is 1.5 years while the internal rate of return is 0.70. Moreover, the system presents relatively proper environmental benefits based on the obtained outcomes from the exergoenvironmental study; the exergoenvironmental factor, exergy stability factor, and sustainability index are 0.50, 0.56, and 1.6, respectively.

Characteristic Investigation of a Novel Aircraft SOFC/GT Hybrid System under Varying Operational Parameters

In this study, the implementation of a solid oxide fuel cell–gas turbine hybrid engine for primary propulsion and electric power generation in aircraft is investigated. The following three parameters, which are crucial in attaining optimal performance at any point in the flight profile, were identified: the oxygen-to-carbon ratio of the catalytic partial oxidation reformer, the fuel utilization factor of the fuel cell, and the airflow split ratio at the outlet of the high-pressure compressor. The study assesses the impact of varying these parameters within specified ranges on the performance of the hybrid system. At the design point, the system yielded a total power output of 1.96 MW, with 102.5 kW of electric power coming from the fuel cell and 7.9 kN (1.86 MW) of thrust power coming from the gas turbine. The results indicate that varying the oxygen-to-carbon ratio affected the fuel cell’s fuel utilization and resulted in a slight decrease in gas turbine thrust. The fuel utilization factor primarily affected the power output of the fuel cell stack, with a minor impact on thrust. Notably, varying the airflow split ratio showed the most significant influence on the overall system performance. This analysis provides insights into the system’s sensitivities and contributes to the development of more sustainable aircraft energy systems.

Thermo-Economic Analysis of Solar-Powered Trigeneration System With Integrated Ejector-Absorption Recompression and Modified Organic Rankine Cycle

Abstract In this study, the organic Rankine cycle (ORC) and hybrid absorption recompression cycle have been modified by the addition of turbine bleeding with regeneration and ejector, making it a unique solar-powered trigeneration system. With this modification, the useful electric power increases by 65 kW due to increased mass flowrate and overall efficiency nearly by 0.7%, and this difference grows as direct normal irradiation (DNI) rises. After identifying these improvements, a parametric study was conducted to determine the optimum value of these operating variables, such as direct normal irradiation, condenser pressure, turbine inlet temperature, and pressure ratio based on the desired outputs and efficiencies of the proposed modified systems. The results indicate that the proposed system is capable of simultaneously generating 315.3 kW of electric power, 1588 kW of heating output, and 501.6 kW of cooling at energy and exergy efficiencies of 80.8% and 25.36%, respectively. Further, in terms of energy one could conclude that only 19.2% of total available energy is getting wasted, but in reality, around 75% of the work potential of the input exergy is getting wasted. The maximum exergy is lost at the solar collector and destructed at heat recovery vapor generator (HRVG), hence requiring careful design to improve their performance. Lastly, an economic analysis of the proposed system has also been conducted, and the payback period is found to be 2.33 years, which ensures its economic viability.

A low-carbon multigeneration system based on a solar collector unit, a bio waste gasification process and a water harvesting unit

Abstract In this study, we introduce and examine a novel multigeneration cycle powered by low-carbon bio-waste and integrated with a solar thermal component. This system is designed to convert sewage sludge into a variety of useful products. The cycle utilizes anaerobic digestion and gasification to produce biogas and syngas. Additionally, it incorporates processes for generating water and hydrogen energy, utilizing the atmospheric water harvesting unit and water/gas shift reaction, sequentially. The system employs a Rankine cycle, a Brayton cycle and two organic Rankine cycles (ORCs) for electricity generation. A significant portion of the heat and electricity in this proposed project is sourced from a waste heat recovery system. This innovative project not only presents a new structure and configuration for product generation but also addresses energy, water and environmental challenges concurrently. The energy system’s performance has been thoroughly assessed in terms of thermodynamics, environmental impact and economic feasibility. The proposed plant is capable of producing an estimated 17 920 kW of electric power, 3207.6 kg/h of hydrogen energy and 5.14 × 10−3 L/s of freshwater. Under these design conditions, the energy and exergy efficiencies of the system were determined to be 35.76% and 40.49%, respectively. Additionally, the exergy sustainability factor, the levelized total emitted carbon dioxide and the unit cost of total products were characterized to be 52.28%, 0.2145 kg per kWh and 0.05219 $ per kWh, respectively.

Optimal design of a solar-driven Kalina system for combined power and desalination purposes

This research study presents a thermodynamic simulation and exergy analysis of a solar-powered Kalina cycle that is integrated with a reverse osmosis desalination (RO) module and a thermoelectric generator (TEG) system. A parabolic through solar collector (PTSC) provides the required heat to drive designed plant. The thermodynamic simulation and exergy examination of the proposed system are carried out using the Engineering Equation Solver (EES). A parametric study of the presented plant to show the primary parameters impacts on the system operation is conducted. The system in this study generates 212.7 kW of electrical power and 44.46 m3/h. The total energy efficiency of the plant is 24.3 %. The inlet thermal energy from PTSC is 876.5 kW. In addition, the thermoelectric module generates 7.26 kW electrical power. Carried out analyses show that the recuperator has the most significant exergy destruction rate among all system components, with 303.2 kW. The unit responsible for the second major exergy destruction value associated with the RO unit, which accounts for 74.22 kW. To examine the influence of influences of parameters like direct normal irradiance (DNI), turbine inlet pressure, and mass flow rate of the Kalina cycle the system case study is presented. It can be observed that increasing DNI parameter from 750 W/m2 to 1000 W/m2 leads in a net output power increment from 279.1 kW to 372.1 kW and increasing fresh-water production from 41.64 m3/h to 48.09 m3/h. Moreover, the calculation shows that increasing DNI has a positive impact on the TEG unit output power too. Enhancing the inlet turbine pressure increases both net output power and fresh-water production by reverse osmosis unit while this increment diminishes the thermoelectric unit electrical output. It can be observed that increasing turbine inlet pressure from 110 kPa to 200 kPa, increases net output power and fresh-water production by about 6.08 % and 3.5 %, respectively.

Exergoeconomic assessment of a high-efficiency compressed air energy storage system

Energy storage systems have a critical part in enabling greater use of intermittent energy resources. For a sustainable energy supply mix, compressed air energy storage systems offer several advantages through the integration of practical and flexible types of equipment in the overall energy system. The primary advantage of these systems is the management of the duration of the peak load of multiple generation sources in ‘islanded operation’ without connection to the electricity network. Here, research introduces and analyzes a novel multigeneration system for electrical power, cooling, heating, potable water, sodium hypochlorite, and hydrogen production to improve the industrial aspects of the system for more profitability and efficiency with lower environmental impacts. The system involves three main sub-systems: CAES, combined cooling, heat & power, and a desalination unit. To assess the performance of the system, technical, economic, exergoeconomic, and exergoenvironmental studies are conducted. The results regarding the energy and exergy studies reveal that the system presents great potential for reliable operation during peak demand hours. The round-trip efficiency is 74.5 % producing 1721 kW of electrical power with concurrent cooling and heating loads at 272.9 and 334.6 kW, respectively. Economically, the levelized costs of heating/cooling, clean desalinated water, and electricity are 26.4 US$/GJ, 2 US$/lit, and 4.5 cents/kWh, respectively. Finally, the outcomes of the exergoenvironmental study display that the sustainability index for the system is 1.7.

Introducing AI applications in engineering education (PBL): An implementation of power generation at minimum wind velocity and turbine faults classification using AI

AbstractThis article explores the integration of artificial intelligence (AI) applications into project‐based learning (PBL) education as a means to enhance students' education. Specifically, the implementation of AI in the context of power generation is addressed, focusing on achieving power generation at minimum wind velocity and classifying turbine faults using AI techniques. The researchers have proposed a novel generating unit which is going to generate 1 KW of electric power at a specific flow rate of air and the generated power will be stored in the battery bank through the charge controller and then the load is driven from the battery through an inverter. Iron or core losses (Hysteresis, Eddy Current losses) can be acknowledged as one of the major reasons for the inefficiency of conventional generators, therefore anovel coreless model generator was proposed which also improved efficiency and reduces drag. Wind Turbine prototype was fabricated and deployed for the testing and validation of the proposed novel design. The design produced outstanding power ratings and electrical generation characteristics compared with other existing strategies at minimal air flow. Results proved that the proposed coreless axial flux generator has the capability to produce a better power rating compared with the existing wind turbine generators. Proposed Axial flux achieved 10.73 watt power at wind velocity at around 80 rpm. At a wind velocity of 10 m/s and around 800 rpm 313–330 kwh was produced by the proposed generator while the conventional generator produced around 300 kwh. The proposed generator design performed 35% better in terms of production efficiency under load and no load conditions. Moreover, faults in turbines are very common due to the various temperatures, therefore the faults have been classified using state‐of‐the‐art AI‐based classifiers. A comparison of space vector modulation (SVM) and Naive Bayes classifiers was performed in the study to classify wind turbine faults. It was found that both classifiers performed well in achieving high accuracy. SVM achieved a slightly higher accuracy of 0.9861 compared with Naive Bayes, which achieved an accuracy of 0.967. Based on the results, it can be inferred that SVM may be a more suitable classifier for wind turbine fault classification. The case study results demonstrated the potential of AI applications in PBL education, offering students a multidisciplinary learning experience that enhances their technical knowledge, problem‐solving skills, and teamwork abilities.

Pra Rancangan Pabrik Epiklorohidrin dari Diklorohidrin dan Natrium Hidroksida dengan Kapasitas 50.000 Ton/Tahun

The rapid development of the chemical, automotive and electronic industries has made the demand for epichlorohydrin increase every year. Currently there is no epichlorohydrin factory in Indonesia so that the industry's need for epichlorohydrin is met from imports. Therefore, the establishment of an epichlorohydrin factory has quite positive prospects for reducing these imports. The preparation of epichlorohydrin begins by reacting dichlorohydrin with sodium hydroxide with a mole ratio of 5 : 1 in 2 stirred tank flow reactors (RATB) at a reactor temperature of 80 ℃ and a pressure of 1 atm. This reaction takes place with an optimum conversion of 95.4% and is exothermic so water cooling is used to maintain the operating temperature. The utilities needed consist of 200183.1275 kg/hour of water, 74 m3/hour of compressed air, 2170.3770 kW of electric power supplied from PLN with a backup generator. The required fixed capital is Rp. 396 billion and working capital of Rp. 420 billion. Production costs (manufacturing costs) are Rp. 2 trillion, and general expenses are Rp. 616 billion. Profit before tax is IDR 100 billion and after tax is IDR 65 billion. This factory is classified as low risk with a Return Of Investment (ROI) before tax of 25.28% and 16.43% after tax. Pay Out Time (POT) before tax is 2.83 years and after tax is 3.78 years). Net Present Value (NPV) IDR 47 billion. Break Event Point (BEP) 40.69 % and Shut Down Point (SDP) 33.13 %.

Comparative Thermodynamic Optimization of Organic Rankine Cycle Configurations for Geothermal Power Generation from an Abandoned Oil Well

This study was aimed at quantifying the net electrical power producible from an abandoned oil well in Nigeria using different organic Rankine cycle (ORC) configurations and working fluids. The geological features of a typical Nigerian oil well were employed in the study and a borehole heat exchanger was used for simulating the thermodynamic parameters of the heat source. Specifically, a subcritical ORC without a recuperator (SBC), a subcritical ORC with a recuperator (SBC-R), a supercritical ORC without a recuperator (SPC), and a supercritical ORC with a recuperator (SPC-R) were analyzed, using R115, R236fa, and R1234yf as working fluids. Results showed that between 272 kW and 875 kW of electrical power could be produced from the abandoned oil well using the most basic ORC configuration (SBC). Furthermore, it was obtained that the introduction of a recuperator would increase the ORC net power by about 13% for R236fa, 33% for R1234yf, and 107% for R115. Similarly, a switch from a subcritical ORC to a supercritical ORC configuration would increase net power for all the working fluids. Specifically, an increase in net power was estimated at 3.6% for R236fa, 46% for R1234yf, and 152% for R115 regarding a switch from the SBC to the SPC. Moreover, decreasing the condensation pressure of the ORC plants was observed to improve net power in all cases.

Development and assessment of a thermochemical cycle and SOFC-based hydrogen energy system as a potential energy solution for the peak demand in a sustainable community

In this study, an integrated energy system is presented in which hydrogen is produced via the thermochemical cycle. The presented system would provide a potential solution for storing excess electric power in terms of hydrogen generation for a sustainable community. Principles of exergy and energy are utilized to analyze the presented system in terms of exergy and energy efficiencies. The simulation result shows that with the help of the developed system, 0.36 kg/h of hydrogen can be generated, which is utilized via SOFCs to produce and electrify the houses. Additionally, 1000 kW of electric power with 3.6 kW of heating can be supplied via the developed system. With the use of thermochemical cycle considered in the present study, one can produce hydrogen with an energy efficiency of 79.6% and exergy efficiency of 62.9%. Furthermore, to see the impact of different factors on the operation of the developed system, a parametric study is also conducted by changing factors like solar irradiation, the inlet temperature of the molten salt, and the outlet temperature of the solar collector.

Electric Load Modeling for Managing Electric Energy Consumption Through the PDCA Cycle in the Library Building of Andalas University

The need for electrical energy in the public building sector is quite dominant, reaching 33-40% of the total energy consumption of all sectors. To control electrical energy in buildings effectively, an Energy Management System (EMS) is needed. EMS stage consists of Plan-Do-Check-Act (PDCA). The study conducted in this research is on how to use the PDCA cycle method to model the consumption of electrical energy in campus buildings in a sustainable manner. Modeling of energy-efficient electrical loads is formed in several ways: modeling by replacing T8 fluorescent lamps and CFLs with LED, modeling by replacing non-inverter AC with inverter AC, modeling by the number of library visitors, modeling by improving the power factor, and finally, modeling with a combination of the four previous models. Modeling using LEDs results in savings of 1,464 kWh per month; inverter AC modeling saves 1742 kWh per month; modeling by adjusting the number of visitors saves 857 kWh per month; and modeling by improving the power factor saves 56 kWh per month. This electrical load modeling can save up to 8 kW of power outside of the library's operating hours. Meanwhile, during operational hours, the modeling library can save up to 30 kW of electric power

Design a novel solar based system integrated with humidification-dehumidification unit and re-compression sCO2 cycle for sustainable development

This paper discusses thermodynamic modeling of a power generation cycle, cooling, and freshwater with the employment of solar energy. The introduced system has different subsystems; solar dish collector, a re-compression sCO2 Brayton cycle integrated with a combined Rankine power-ejector refrigeration system and humidification and dehumidification desalination unit driven with a solar dish system. The considered system is analyzed in the context of thermodynamics index and criteria such as irreversibility, freshwater production, energy and exergy efficiencies, and environmental metric. The performance-affecting primary variables are determined through a parametric evaluation of the suggested system. According to the results, the system is capable of producing 83.3 kW of electrical power at the design point and 3.1 kW of cooling as well as 41.54 kg/h of freshwater. A more accurate analysis of exergy destruction shows that solar dish and heat exchanger-4 have the most significant rate of exergy destruction. In addition, parameters such as solar radiation intensity, compressor pressure ratio, and entrainment ratio are parametrically analyzed. The results indicated that increasing entrainment ratio from 0.3 to 0.6, will increase the refrigeration capacity from 2.33 kW to 4.66 kW and the operation of Turbine 2 from 15.96 kW to 18.63 kW. Also, enhancing the solar radiation intensity from 650 W/m2 to 950 W/m2 has different influences the system outputs so that increasing the solar intensity will reduce the performance of the cooling cycle and increase the freshwater produced.

An energy-efficient vacuum system as an alternative to the inefficient use of compressed air for the yarn suction gun

The yarn suction gun (YSG) is used to draw the running yarn in the initial phase and when changing the bobbin in a continuous yarn production and is usually operated with compressed air. With a typical overall efficiency of compressed air generation, treatment and delivery, the electrical power requirement increases to over 75 kW just to operate a single YSG. Such high electrical power consumption must be addressed. One of the most effective ways to reduce the cost of compressed air generation and treatment is to replace the existing technology with one that is less energy intensive. Based on centrifugal blowers used in vacuum cleaners, a prototype was built and connected to various mixing chambers. Simulations and measurements were performed to evaluate the tension force acting on the yarn. Research on the use of vacuum for yarn suction is presented. It is estimated that after optimizing the suction by using vacuum, only 20 kW of electrical power will be required for one YSG, halving the cost of the current approach using compressed air generation. HYPOTHESIS 1: To significantly improve the efficiency of yarn suction gun (YSG), the existing technology must be significantly modified or reinvented. HYPOTHESIS 2: The application of convergent-divergent nozzles enables supersonic airflow velocities in rough vacuum. HYPOTHESIS 3: A modified YSG can be operated with a rough vacuum instead of compressed air to achieve significantly higher overall efficiency and reduce power input and carbon footprint.

Modeling and Design Optimization of an Electric Environmental Control System for Commercial Passenger Aircraft

The aircraft environmental control system (ECS) is the second-highest fuel consumer system, behind the propulsion system. To reduce fuel consumption, one research direction intends to replace conventional aircraft with more electric aircraft. Thus, new electric architectures have to be designed for each system, such as for the ECS. In this paper, an electric ECS is modeled and then sized and optimized for different sizing scenarios with the aim of minimizing fuel consumption at the aircraft level. For the system and for each component, such as air inlets and heat exchangers, parametric models are developed to allow the prediction of relevant characteristics. These models, developed in order to be adapted to aircraft design issues, are of different types, such as scaling laws and surrogate models. They are then assembled to build a preliminary sizing procedure for the ECS by using a multidisciplinary design analysis and optimization (MDAO) formulation. Results show that the ECS design is highly dependent on the sizing scenario considered. An approach to size the ECS globally with respect to all the sizing scenarios leads to an ECS that accounts for around 200 N of drag, 190 kW of electric power, and 1500 kg of mass for the CeRAS aircraft.

Generating electricity from palm waste by gasification technique coupled with externally fired gas turbine: a case study

ABSTRACT Recently, renewable energy sources have become an encouraging solution to the availability and environmental problems arising from using fossil fuels for energy production. The article’s goal is to provide a reliable and doable path toward producing electricity from biomass by using palm waste (fronds, empty fruit bunches, and trunks). The system is simulated using Cycle-Tempo software. Waste was gasified at 800°C using a downdraft fixed-bed reactor to produce syngas. After that, a producer gas flow of around is sent to an externally fired gas turbine (EFGT), where it is promptly burned at atmospheric pressure to produce electricity. According to the simulation’s outcomes, palm fronds are the waste that worked best as a feedstock, and an estimated 390 kW of electric power could be generated by the externally fired gas turbine with a 19% electrical efficiency. The producer gas had a good molecular composition (H2 15.02%, CO 18.1%, CH4 1.25%, CO2 10.79%, H2O 8.17%, and N2 46.08%), a low heating value of up to (4.16 MJ/kg), a gasification efficiency of 77%, and a CHP efficiency of 61%. A comparison of the findings with previously published literature revealed that the proposed technology allows for the production of syngas with a satisfactory composition from palm fronds.

UiS Subsea-Freight Glider: A Large Buoyancy-Driven Autonomous Cargo Glider

Abstract This study presents the baseline design for the autonomous subsea vehicle capable of traveling at a lower speed of 1 m/s with an operating range of 400 km. Owing to UiS subsea-freight glider’s (USFG) exceedingly economical and unique propulsion system, it can transport various types of cargo over variable distances. The primary use-case scenario for the USFG is to serve as an autonomous transport vessel to carry CO2 from land-based facilities to subsea injection sites. This allows the USFG to serve as a substitute for weather-dependent cargo tankers and underwater pipelines. The length of the USFG is 50.25 m along with a beam of 5.50 m, which allows the vessel to carry 518 m3 of CO2 while serving the storage needs of the carbon capture and storage (CCS) ventures on the Norwegian continental shelf. The USFG is powered by battery cells, and it only consumes a little less than 8 kW of electrical power. Along with the mechanical design of the USFG, the control design is also presented in the final part of the paper. The maneuvering model of the USFG is presented along with two operational case studies. For this purpose, a linear quadratic regulator (LQR)- and proportional-integral-derivative (PID)-based control system is designed, and a detailed comparison study is also shown in terms of tuning and response characteristics for both controllers.

BINARY ELECTRICAL GENERATING INSTALLATION FOR UTILIZATION HEAT OF BOILER FLUE GASES

The work is devoted to the development of modern thermal schemes for the production of electrical energy while utilizing the heat of flue gases from boilers of power units. On the example of a typical district boiler house, the parameters and potential of heat discharged into the atmosphere with the flue gases of boilers are investigated, and it is determined that they are sufficient to generate electrical energy by implementing the so-called organic Rankine cycles. To utilize the heat of exhaust gases with a temperature of 280 °С at a flow rate of 10 kg/s, a three-loop power generating plant similar to those used in geothermal energy was studied. In the process of conducting research related to solving the problem, the thermal scheme was improved. A number of turbine working bodies that meet the necessary requirements are analyzed and the most suitable ones are recommended. Taking into account the characteristics of the heat source, in order to determine the rational configuration of the circuit, 50 calculations of thermal circuits of power plants on different working fluids were performed. The research results showed that the efficiency (electrical efficiency) and power of the turbine cycle are determined by the waste heat potential, the thermodynamic properties of the working fluid, the structural and parametric characteristics of the circuit. Among the studied indicators, the best indicators are: electrical efficiency of 20,6 %, a "useful" electrical power of 357 kW at a flue gas temperature of 131 °C was a three-circuit utilization plant with working bodies Water / R-245fa / R-245fa. The variant of the circuit with working fluids Water / R-600a / R-600a lost ~ 8 kW of electric power to the best variant, but was recognized as more promising, since R-600a (isopropane) Freon has consumer advantages over R-245fa. Computational studies of the binary thermal scheme of the power plant were also carried out, which showed that it is rational to use Water for the 1st circuit, R-600a for the 2nd circuit. This solution made it possible to obtain the calculated "useful" electric power of the energy complex ~ 290,8 kW (1st circuit ~ 129 kW, 2nd circuit ~ 161,8 kW). The loss of the binary scheme in terms of "useful" electric power to the promising version of the three-loop scheme is compensated by a significant simplification of the thermal scheme and, as a result, significantly lower capital costs. The specific mass of the proposed heat exchange equipment of the installation with a binary thermal scheme is ~ 150 kg/kW. Taking into account the properties of the working fluids, a preliminary study of the structures of the turbines of the 1st (Water) and 2nd (R-600a) circuits was carried out. For the 1st circuit, it is proposed to use a 6-stage axial turbine, for the 2nd – a single-stage radial. The geometric characteristics of the flow parts of turbines are determined by calculation. A preliminary simplified assessment of a simple payback period indicates good prospects for the implementation of the proposed energy-saving installation.

Dynamic simulation and techno-economic assessment of hydrogen utilization in dual fuel (Hydrogen/biogas) micro gas turbine systems for a wastewater treatment plant

Due to the commitments of many governments, electrical power production from renewables hopefully continues to become widespread at a rapid rate to revolutionize energy infrastructures. Nevertheless, this green power seems to be wasted due to seasonal power swings, grid restrictions, and curtailment. The present research investigates the practicability of hydrogen injection into biogas from anaerobic digestion to generate electricity for a deployed wastewater treatment plant. A Polymer electrolyte membrane electrolyzer powered by Photovoltaic panels would produce hydrogen. An array of commercialized micro gas turbines has been suggested to create electrical power and thermal demand. Transient modeling was carried out using TRNSYS software to analyze the plant's performance from the thermodynamics and techno-economic perspectives. It is found that when biogas mass flow rate fluctuates, hydrogen could be effectively injected into biogas to fuel micro gas turbines. The results revealed that injecting hydrogen into biogas results in up to a 30% reduction in CO2 emissions, with two micro gas turbines producing more than 265 kW of electrical power at full load. LCOH and payback time would be 8.3 $/kg H2 and 6.5 years, respectively, for a hypothetical scenario in which electrolyzer size is anticipated to supply the maximum necessary hydrogen. Also the results indicate that electrical power and thermal energy of 70kWe-400kWe and 120kWth-500kWth could be reached annually, and the highest efficiency for the power generation, CHP, and the overall system becomes 37.5%, 83%, and 78%, respectively.

Dependence of electrical power output on collector size in Manzanares solar chimney power plant: an investigation for thermodynamic limits

Abstract Solar energy is at the forefront of renewable energy sources. Depending on the increasing energy need, the use of clean energy sources is inevitable in terms of human health and the environment. The application of solar chimney power plants (SCPPs) is one of the not very old and promising systems. SCPPs are systems that attract attention with their long life and simple working principles. SCPPs have three basic elements: collector, chimney and turbine, and optimizing these elements in terms of design and operational parameters plays a key role in the performance parameters of the system such as power output and efficiency. This study, which references the Manzanares pilot plant, aims at the collector dimensioning of the system to achieve the optimum power output and efficiency from the plant and to assess the upper thermodynamic limits of the Manzanares pilot plant. The most challenging aspect of SCPPs, in general, is their high cost, and large collector areas constitute a notable fraction of this cost. Therefore, for performance and cost optimization, collector dimensioning is of vital importance and reveals the innovative aspect of this study. For this purpose, a 3D 90° computational fluid dynamics model is created with ANSYS engineering software. RNG k-e turbulence model and discrete ordinates solar ray-tracing algorithm are applied to the model. In the study, solutions are taken in the dimensions of the pilot plant with an ambient temperature of 290 K and two different radiation intensities of 800 and 1000 W/m2. The collector radius (Rcoll) is increased up to 2 times the reference size and its effect on the system is evaluated. It is found that the plant, which produces an electrical power of 46.6 kW at 800 W/m2, will generate 138.3 kW of electrical power if the Rcoll is doubled. The optimum collector radius rate (Xcoll) is found to be in the range of 1.00–1.50. For the greater values of Xcoll than 1.50 (183 m), it is observed that the exponential increase in power output stops, and cost-related upper thermodynamic limits are achieved.