Total Cost Rate Research Articles

Multi-criteria optimization of a combined power and freshwater system using modified NSGA-II and AHP-entropy-topsis

This paper proposed an innovative hybrid system to generate electricity and fresh water with higher energy efficiency. A subsystem is employed by integrating DCMD and heat pump to recover waste heat of PEMFC to produce fresh water. The thermodynamic and exergoeconomic models are established to evaluate the system comprehensive performance. Compared with the PEMFC alone, the results demonstrated that the proposed hybrid system achieves a 42.07 % increase in energy efficiency and provides 177.86 kg/h of fresh water. The components with high exergy destruction are PEMFC, Relief value, Inverter, Separator 2 and DCMD with the exergy destruction rate of PEMFC stack accounting for 54.55 %. The parametric analysis results indicate that the variation of the membrane filament number, feed and permeate flow rates all have evident impacts on the thermodynamic and economic performances of the hybrid system. The multi-objective optimization is conducted by adopting NSGA-II and three decision-making methods. The optimal solution obtained by AHP-entropy-TOPSIS approach for the net power out, exergy efficiency, WPC, and total exergy cost rate are 96059W, 0.5293, 0.2995 $/m3, and 14.27 $/h, respectively. In addition, the obtained results shown that the simulation times of NSGA-II are significantly reduced from 89.30 to 11.20 h by introducing BP-ANN to improve the simulation efficiency.

Optimal 4E evaluation of an innovative solar-wind cogeneration system for sustainable power and fresh water production based on integration of microbial desalination cell, humidification- dehumidification, and reverse osmosis desalination

Reliable freshwater production is vital for tackling two of the most critical challenges the world is facing today: climate change and sustainable development. Present work presents an innovative cogeneration system based on solar and wind energies for sustainable production of freshwater, power, and wastewater treatment. For freshwater production and wastewater treatment in this system, the integration of a microbial desalination cell with a humidification-dehumidification and reverse osmosis desalinations has been used. The mentioned systems provide their heat demand from solar energy, and when solar radiation is unable to provide this heat, a hydrogen internal combustion engine drive produces the required heat for the freshwater plant. Excess heat from the hydrogen internal combustion engine is fed into the organic Rankine cycle for more power generation in the whole system to reduce system waste heat and increase efficiency. PEM electrolyzer has been used to supply the hydrogen needed by the internal combustion engine, and this system uses wind turbines to supply the power demand. To evaluate the performance of the whole system, energy, exergy, exergeoeconomic, and exergoenvironmental (4E) analyses have been carried out. Finally, to improve the performance parameters of the system, multi-objective optimization using the Salp swarm algorithm has been used. Investigation of the results show that the proposed system can produce 720 kW of electricity and 5.36 m3/h of freshwater. The energy efficiency of the system is 22.09 %, and its overall cost rate and overall environmental impact rate are 540.33 $/hr and 17.37 Pt/h, respectively. Among the qualitative results obtained in this research, it is possible to mention the high exergy destruction, cost destruction, and environmental impact destruction of the internal combustion engine compared to other equipment used in the proposed system, and this point shows the need to improve this equipment, similar to previous researches. The five-objective optimization results of the proposed system showed that the performance parameters of the system, such as polygeneration energy efficiency, total cost rate, and total environmental impact rate, can be improved by 6.2 %, 1.44 %, and 0.52 %, respectively. The payback period of the proposed system in the optimal state is 6.95 years.

Analysis and Optimization of a Biomass Heated Two-Stage Desiccant Cooling System Used for Greenhouse Cultivation in Hot and Humid Climates

Abstract This paper presents a multi-objective optimization of a biomass heating-based two-stage desiccant-supported greenhouse cooling system used for Orchids cultivation in hot and humid weather conditions. The simulation model has been developed considering thermodynamics, economic, and environmental aspects. The thermal coefficient of performance (COPth) of the system and greenhouse temperature have been predicted for the five most impactful months (March, May, August, September, and December) corresponding to the respective seasons of spring, summer, monsoon, autumn, and winter of a calendar year. The system maintains the peak average greenhouse temperature at a maximum of 26 °C during the prominent sunshine period (12 h) in May while ensuring a minimum of 18 °C during nighttime. In terms of system components, the residue boiler stands out as the significant contributor to exergy destruction (45%), followed by regeneration heater 1 (22%), desiccant wheel 1 (7%), and the heat recovery water heater (6%) during the critical operational month of August. Multi-objective optimization has also been conducted using the optimization toolbox provided in matlab-R2017a to determine the optimal performance and operating conditions of the two-stage desiccant cooling system. The optimal conditions display the corresponding total cost rate, considering capital and maintenance costs, operating costs, CO2 penalty costs, and exergetic efficiency.

A comprehensive 6E analysis of a novel multigeneration system powered by solar-biomass energies

This study presents a novel multigeneration system comprising five different cycles driven by a combination of solar and biomass energy resources. This system includes a modified gas turbine cycle, a trans-critical CO2 cycle (TCO2), a steam Rankine cycle, a biomass-fueled boiler, and a solar collector. The gas turbines exhibit limited thermal efficiency, primarily due to substantial heat losses. Consequently, the TCO2 cycle and the steam Rankine cycle are integrated into the system to improve performance. An innovative aspect of this study is the utilization of a unique configuration of transcritical CO2 and steam Rankine cycles, combined with biomass and solar energies, aimed at maximizing energy recovery and minimizing waste. Furthermore, a proton membrane electrolyzer (PEME) is integrated into the system for hydrogen production, along with a proton membrane fuel cell (PEMFC) to increase electricity generation. In this comprehensive analysis, in addition to energy and exergy analyses, exergoeconomic, exergoenvironmental, emergoeconomic, and emergoenvironmental analyses are conducted. The results indicate that the proposed system achieves notable energy and exergy efficiencies of 20.2 % and 15.2 %, respectively. The total investment cost rate for the system equipment is 0.007554 $/s and the system's environmental impact is 0.0008611 pt/s. The results of the emergy analysis reveal that the emergoeconomic values of the streams are lower than the corresponding environmental values, primarily due to the higher environmental impact throughout the components' life cycle compared to their economic value.

Towards building clean hydrogen supply chain network in Iran for future domestic demand and exports. Part II: 4E analyses of prioritized scenarios

In continuation of the previous part, this paper comprehensively focuses on energy, exergy, exergo-economic, and environmental (4E) analyses of two prioritized clean hydrogen (H2) supply chains pathways. The first scenario relies on domestic demand, involves blue H2 production and storage using steam methane reforming coupled with carbon capture and storage through H2 conversion to hydrogen carriers in liquid form (ammonia and methanol) aligned with the existing infrastructure. The second scenario involves green H2 production from photovoltaic panels as the power source follows by storing H2 in liquid form which is more suitable to export. The findings indicate that the blue H2 system outperforms the green H2 system in terms of energy and exergy, boasting 41.38% and 22.15% compared to 12.16% and 12.75%, respectively. However, when examining economic parameters, the blue H2 system shows a total cost rate of 1976 US$/h, a net profit of $747.2 million (mn) at the end of its lifetime, and a payback period of approximately nine years. Conversely, the green H2 system demonstrates economic indicators of a 125.2 $/h as a total cost rate, $1.26 billion (bn) net profit, and an 8.17 year payback period. Moreover, the production cost rates for blue and green H2 are 1.32 $/kg and 2.55 $/kg, respectively; while the CO2 emissions rate in the blue H2 system is 10.71 kg/s. The green H2 system prevents 19.84 kg/s of CO2 emissions resulted a significant environmental cost reduction of 2.28 $/kg H2. This analysis facilitates a thorough comparison of these two clean H2 production and storage systems, offering insights for policymakers across performance, economic, and environmental dimensions.

A novel pathway for achieving efficient integration of SOFC/SOEC and addressing photovoltaic duck curve challenge

This study presents a novel method that directly integrates SOFC oxy-fuel combustion and SOEC co-electrolysis to tackle the challenges of high-energy consumption of SOFC/SOEC integration and photovoltaic duck curve. To explore the viability of this method, a biomass-solar complementary scenario is pioneered and its performance is assessed from thermodynamic and economic standpoints. The results show that the studied scenario achieves CHP and exergy efficiencies of 50.67% and 43.68% with the corresponding total product cost rate (Ċtot) of 45.44 $/h and the levelized cost of products (cp) of 14.61 $/GJ under the design conditions. The system annually produces 17485 tons of freshwater and 1432 tons of oxygen. Exergy analysis identifies the afterburner (AB-II) and supercritical CO2 recompression power cycle (SCRPC) as the primary contributors to exergy destruction with 381.74 kW and 343.62 kW, which alone account for over half of the total irreversibility. Increasing the isentropic efficiency of gas turbine (ηGT) and SOFC operating pressure (Pop) improves the overall thermodynamic performance, but enhancing SOFC current density and gasification temperature has adverse effects. Across varying Pop andηGT, there exist optimal Ċtot (44.83 $/h) and cp (14.47 $/GJ), which are obtained at ηGT of 80% and Pop of 600 kPa, as well as at ηGT of 87.14% and Pop of 800 kPa, respectively. This research can provide a reference for the development of cyclic energy storage technologies and the low-carbon transition in the energy fields.

District heating based on exhaust gas produced from end-of-life tires in Erzincan: Thermoeconomic analysis and optimization

This paper presents the thermoeconomic analysis and optimization of the Erzincan Waste Tire Recycling and Power Plant (EWTRPP) in Turkey and its waste heat-based district heating (DH) system. A thermoeconomical method, namely the specific exergy costing (SPECO), is applied to allocate cost flows through subcomponents of an actual existing plant. Besides, the obtained thermoeconomic results are improved by using an optimization method, namely non-dominant sorting genetic algorithm (NSGA-II), considering the temperature of the exhaust gas discharged to the atmosphere (T25), the thermal conductivity value of the insulation material (ki) and pipe roughness value (s). The energy and exergy efficiencies of the existing plant are found to be 27.37% and 35.57%, respectively, considering the data of the actual plant. Moreover, the energy and exergy efficiencies of the waste heat-based DH system are found to be 43.08% and 55.99%, respectively. The total cost rate of the overall system is deduced 13.98 $/hby means of SPECO method. According to the results of the NSGA-II optimization method, the exergy efficiency and total cost rate of the overall system are evaluated as 6.93% and −2.51 $/h, respectively. Furthermore, it is also proposed that 1304 dwellings can be heated owing to the DH system utilizing the existing exhaust gas.

The burden of end-stage renal disease in Khartoum, Sudan: cost of illness study

Background and purpose The incidence of end-stage renal disease (ESRD) in Sudan is increasing, affecting the economic status of patients, caregivers and society. This study aimed to measure ESRD’s costs, including direct and morbidity indirect expenditures, and to investigate any associated factors and financial consequences. Materials and methods This cross-sectional study used a standardized questionnaire to collect data from 150 ESRD patients who had been receiving dialysis for at least one year before the time of data collection at 13 specialized renal centres in Khartoum state. Data about sociodemographic, clinical, and economic factors were gathered, and their relationship to the cost of ESRD was examined using both bivariate (Man Whitney test, Kruskal Wallis test and Spearman correlation) and multivariate analytical procedures (multivariate linear regression). Results This study reported a median direct per capita ESRD cost of 38 600 SDG ($1 723.2 PPP) annually with an interquartile range of 69 319.3 SDG ($3 094.6 PPP). The median morbidity indirect cost was estimated to be 0.0 ± 3 352 SDG ($ 0.0 ± 149.6 PPP) per annum. In 28.8% of cases, the patients were their family’s primary income earner and over 85% were covered by medical insurance. Our study found that none of the study variables were significantly associated with the total cost of ESRD. Conclusion and limitations Our findings point out considerable direct out-of-pocket expenses and productivity losses for patients and their households. However, these results should be carefully applied for comparison between the different countries due to differences in the cost of medical interventions and insurance coverage. Further longitudinal studies and studies on health finance and insurance policies are recommended.

Simultaneous economic and exergetic optimization of a municipal solid waste incineration plant for sustainable power generation

Simultaneous economic and exergetic optimization of a Municipal Solid Waste (MSW) incineration power generation plant is performed in this research for reaching the higher power production, lower payback period and higher exergy efficiency with more stringent environmental protection. To reach these goals, modeling and optimizing of MSW incineration plant were performed by the ASPEN Plus and MATLAB software respectively. The first method named exergo-economic, used a single objective function (the sum of exergy destruction cost rate and total equipment cost rate). The second method used multi-objective optimization with two objective functions (the total equipment cost rate and exergy efficiency). Results of applying the exergo-economic optimizing for a local MSW plant with feeding rate of 30 ton/hr provided a system which increased the power generation for about 0.65% and decreased the payback period for 0.2 year in comparison with that for a single economic optimization method.Results showed that for generating the same power output from MSW plant (10139.5 kW), 44,116,660 m3/year natural gas fuel with 7,824,371 $/year fuel cost was required.Finally, the flue gas cleaning and carbon dioxide removal systems were also modeled for the optimum designed MSW incineration plant.

Comprehensive analysis and optimization of a low-carbon multi-generation system driven by municipal solid waste and solar thermal energy integrated with a microbial fuel cell

Abstract In this article, a novel multi-generation plant is addressed and assessed from the energy, exergy, exergoenvironmental and exergoeconomic points of view. The multi-generation plant is composed of two main units: one unit for energy production and another unit for carbon capture and methanol synthesis. Biomass fuel, solar energy and seawater are the main nutrients in the plant. Steam, Brayton, organic Rankine and Kalina cycles have been employed to generate electricity. A linear Fresnel collector-driven solar farm is considered as an auxiliary heat source. In addition, an integrated desalination unit based on a multi-effect desalination unit, a microbial fuel cell and a reverse osmosis unit has been installed in the multi-generation plant. The proposed structure for the offered multi-generation plant is designed under a new configuration and layout that had not been reported in the publications. From the outcomes, the multi-generation plant can produce 69.6 MW of net electricity, 0.53 kg/s of methanol, 0.81 kg/s of oxygen gas, 73.8 kg/s of fresh water and ~0.015 kg/s of hydrogen gas. Under such performance, the offered multi-generation plant can be 51.72 and 27.5% efficient from the points of view of energy and exergy, respectively. Further, the total cost rate and environmental impact of the plant are ~3378 US$/h and 294.1 mPts/s, respectively. A comparative analysis is developed to exhibit the superiority of the planned multi-generation plant. A five-objective optimization is also developed to achieve the optimum design data and outcomes of the plant.

A comprehensive analysis and multi-objective optimization of a sustainable production system based on renewable energies

The adoption and promotion of clean and sustainable energy sources bring about significant benefits to the environment, economy, and society, both in the present and for future generations. This study introduces a pioneering solar-wind biomass multi-generation system, aimed at facilitating the sustainable production of electricity, fresh water, hydrogen, and heating. This system provides a comprehensive evaluation of the influence of environmental conditions and design factors on system efficiency, taking into account the crucial aspects of energy, exergy, economy, and environment (4E). Additionally, a meticulous sensitivity analysis is conducted to identify and prioritize key decision variables that exert the most significant impact on the overall system. Ultimately, the multi-objective optimization is conducted by taking into account various priorities in four distinct scenarios. This approach enables the simultaneous or individual optimization of the system's useful objective functions in relation to the total cost rate. Subsequently, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method is employed to determine the ideal point that best fulfills the optimization criteria. By employing TOPSIS, this study aims to provide a robust and systematic decision-making framework for scenario selection in various domains. By evaluating the optimal points across various scenarios, the first scenario yields the most favorable outcomes in terms of the system's useful outputs. These include an exergy efficiency of 19.63 %, hydrogen production of 11.07 kg/h, fresh water production of 34.16 kg/s, and a total cost rate amounting to 213.80 $/h. Additionally, a considerable decrease of 22.65 % in the total cost rate is noted at the optimal point.

Investigation on combining multi-effect distillation and double-effect absorption refrigeration cycle to recover exhaust heat of SOFC-GT system

This study introduces the double-effect absorption refrigeration cycle (D-ARC) and multi-effect distillation with thermal vapor compression unit (MED-TVC) technologies to recover exhaust heat from the SOFC-GT system. This scheme can efficiently utilize waste heat at various temperature levels while enabling large-capacity cooling and freshwater production. The supercritical CO2 Brayton cycle is employed to facilitate the reliable operation of D-ARC and MED-TVC within their preferred temperature zones while enhancing the power output of the entire system. The techno-economic-environmental evaluation, comparative analysis and sensitivity analysis are performed to explore the feasibility of its engineering implementation. The proposed system obtains thermal, exergic and electrical efficiencies of 78.56 %, 65.41 % and 65.77 % with the total cost rate being 18.53 $/h and freshwater production 829.30 ton/year under design conditions, respectively. Exergy analysis indicates that SOFC and afterburner exhibit the highest irreversibility with values of 21.60 kW and 26.02 kW among all the components. Comparative analysis reveals that the system has exceptional thermal efficiency while exhibiting competitive advantages in electrical and exergic efficiencies compared to similar systems. Sensitivity analysis demonstrates that the electrical efficiency and net power output stabilize at their respective maximum values within the SOFC inlet temperature range of 514.3℃-528.6℃. Moreover, it is a promising option by increasing SOFC operating pressure and GT isentropic efficiency to enhance system efficiency and reduce CO2 emission. This work contributes to the development and waste heat recovery of the SOFC-GT system and other prime power units with similar exhaust gas temperature levels.

Energy, exergy, and exergoeconomic analyses of an air source transcritical CO2 heat pump for simultaneous domestic hot water and space heating

The transcritical CO2 heat pump system experiences significant throttling losses in space heating operation due to the higher temperature of returning water. This paper presents an energy, exergy, and exergoeconomic analyses of an air source transcritical CO2 heat pump integrating a tri-partite gas cooler, which is an effective method to match CO2 temperature glide with water for simultaneous domestic hot water and space heating (DHW+SH) production. A pinch point-based numerical model is developed to find the optimal discharge pressure. This validated model is then utilized to investigate the impacts of water inlet temperature and ambient temperature. Two configurations are examined: one with only DHW supply and the other with DHW+SH supply. The results indicate that combining SH with DHW enhances COP by 7.5% with a 7.9% reduction in discharge pressure at 10 °C ambient temperature and 10 °C water inlet temperature. At a water temperature of 10 °C, exergy efficiency improves by 4%. The compressor accounts for 54%–60% of the total exergy loss. The DHW+SH system exhibits an average exergy destruction reduction of 7.6%. With each 5 °C rise in ambient temperature, the DHW+SH system’s total exergy destruction cost rate decreases on average 7.7% compared to the DHW system. Furthermore, the combined exergy destruction cost rate of GC2 and GC3 in DHW+SH is significantly lower (by 48.2%) than only GC3 in DHW. The exergoeconomic factors of the compressor, gas cooler 2, and gas cooler 3 emphasize the need to decrease their costs to enhance cost-effectiveness.

B-FEF-blockchain based framework to exchange files

Blockchain-based systems have proven to be efficient and capable of resolving the majority of security issues relating to exchange transactions in the system. As a result, it became necessary to move away from the problems of the existence of third parties in the system with an important level of trust; a decentralized method of transferring digital files was created. In this paper we present B-FEF-Blockchain Based Framework to Exchange Files. This solution uses IPFS and the Ethereum blockchain. The suggested method offers irreversible and irreversible records of the transmission and reception of documents. In the work system, it is available to all participants who have successfully registered and depending on the smart contract offered by Ethereum blockchain to start sending and receiving documents according to available applications or needs. In the end, the results of the B-FEF model showed that a single transaction costs about 0.387020062 Ether, that is, it showed a positive side in terms of the total cost rate. Also, in comparison with the methods previously presented in five of the previous researches and based on assessments based on eight basic criteria, the analyses supported our claim that the proposed model fulfills all these criteria. As for the basic trio of confidentiality, integrity and availability analysis, the proposed model proved to meet these fundamentals.

Estudio comparativo de un ciclo transcrítico de dióxido de carbono alimentado por un único ciclo geotérmico flash en los modos de funcionamiento con/sin economizador

Renewable energy, particularly geothermal energy, is on the rise globally. It has been demonstrated that recovering heat lost during geothermal cycles is essential due to the inefficiency of these cycles. This paper pproposes a combined power generation cycle using EES software to model a single-flash geothermal cycle, and a trans-critical carbon dioxide cycle. The study compares the system's performance during its "Without Economizer" and "With Economizer" operational stages. The impact of the economizer on the system's output metrics, including the net power output, energy efficiency, and exergy efficiency, was examined. The results show that the "With Economizer" system's net power output increased from 451.3 kW to 454 kW. The energy efficiency difference between the two systems is based on the first law of thermodynamics, where the value ofthe "Without Economizer" system is 6.036%, and the "With Economizer" system is 6.075%. The system without an economizer had an exergy efficiency value of 26.26%, whereas the system with an economizer reached 26.43%, based on the second law of thermodynamics. Installing the economizer increased the total economic cost rate of the system from 0.225M$/Year to 0.2294M$/Year, which increased the product cost rate from 15.82$/GJ to 16.02$/GJ.

Comprehensive analysis of energy, exergy, economic, and environmental aspects in implementing the Kalina cycle for waste heat recovery from a gas turbine cycle coupled with a steam generator

This study introduces a transformative approach by integrating the Kalina Cycle System (KCS) within a cogeneration of heat and power (CHP) framework alongside a gas turbine (GT) cycle and a single-pressure heat recovery steam generator (HRSG). Through development of thermodynamic and thermo-economic models, a comprehensive assessment of the system's performance is conducted, emphasizing energy, exergy, and exergoeconomic considerations. The outcomes reveal a remarkable enhancement in both 1st and 2nd law efficiencies for the GT-HRSG/KCS-11 system compared to its conventional counterpart. Witnessing an ascent from 53.60 % to 54.31 % in efficiency and an increase from 50.59 % to 51.27 % in 2nd law efficiency underscores the profound impact of the proposed system. Furthermore, a parametric study scrutinizes the influence of diverse design parameters on critical objective functions, encompassing second law efficiencies and the total system cost rate. Findings spotlight the combustion chamber, heat recovery steam generator, and gas turbine as focal points of exergy destruction, revealing crucial insights for system optimization. The combustion chamber, heat recovery steam generator, and gas turbine emerge as pivotal contributors to the total cost rate, highlighting key areas for economic consideration. According to the results, the share of the environmental cost rates in the system cost rate is insignificant.

A comprehensive and comparative study of an innovative constant-pressure compressed air energy storage (CP-CAES) system

Electricity and potable water are two vital resources for the world's population. A pioneering green energy storage system for power and potable water production has been introduced and investigated in this context. The innovative system integrates compressed air, pumped hydro, and thermal energy storage, along with multi-effect desalination. This combination enables the generation of power and potable water without exerting any adverse impact on the environment. This technology manages the start-up time of the desalination unit by using a low thermal energy storage unit and allows potable water to be generated throughout the day. By conducting a comprehensive analysis including energy, exergy, economic, and exergoeconomic, the performance of the system has been carefully examined and the effect of various parameters has also been considered. Finally, the advantages of the proposed system are compared to the conventional system. According to the study, round trip efficiency and total cost rate have been calculated as 62.18% and 618.6 USD/hr, respectively. Based on a case study conducted in the coastal areas of the state of California, the proposed system has the potential to generate 138 m3 of potable water and 88.11 MWh of electricity per day. This could lead to a total profit of 27.65 million dollars with a payback period of 3.82 years.

Exploring an innovative approach to hydrogen generation for fuel cell energy production by integrating a dual organic Rankine system with an absorption chiller powered by geothermal energy

This study delved into the thermodynamic optimization of a geothermal system integrated with a fuel cell unit for energy storage during peak consumption. An innovative system was devised to simultaneously produce cooling, electricity, hydrogen, and freshwater by combining an absorption chiller, reverse osmosis, PEM Electrolyzer, and two double Organic Rankine Cycles. To assess the impact of local weather conditions, case studies were conducted in the cities of Hong Kong (China), Bandar Abbas (Iran), Tepic (Mexico), and Melbourne (Australia). Computational modeling employed EES software, and optimization using Response Surface Methodology aimed to enhance system performance and minimize costs. The geothermal system was engineered to meet the electricity demands of residential households during peak consumption. The optimal results demonstrated that the proposed geothermal system, in its most efficient configuration, could achieve an exergy efficiency of 73.17 % and an energy efficiency of 25.25 % while operating at a cost rate of 74.36 $/h. An economic analysis revealed that among the system components, ORC1 unit and PEME incurred the highest costs. Additionally, the PEME, evaporator, and absorption chiller were identified as the main contributors to exergy destruction. The total exergy destruction rate of the proposed geothermal system is 1840.7 kWh and the total cost rate of the system is 51.73 $/h. Lastly, the assessment of the suggested geothermal system across the studied cities indicated that it performed most effectively in Melbourne, Australia. The results of the study of the production capacity in the four study cities showed that Melbourne has the highest production rate with a rate of 14,573 MWh, Tepic with a rate of 13,425 MWh, and Hong Kong with a rate of 13,174 MWh. The lowest annual rate with the amount of 12,784 MWh belongs to the city of Bandar Abbas. The environmental results showed that by producing 14,573 megawatts of electricity in the city of Melbourne, it is possible to expand 14 hectares of green space per year. Also, prevented the reduction of carbon dioxide emissions by 2972.8 tonsCO2/MWh at 71,349.4 $/tonsCO2. The analysis of the production power of the system showed that the electricity needs of 1533 people can be provided for one year by starting the geothermal system in Melbourne City.

Design, evaluation, and optimization of an integrated proton exchange membrane and double flash geothermal based organic Rankine cycle multi-generation system fed by a biomass-fueled gasifier

This study introduces an innovative approach by formulating and evaluating a synergistic biomass-geothermal structure, emphasizing optimized inter-component connections. The research stands out for its thorough analysis of parameter impacts on the system and variables, addressing an unexplored aspect in integrated energy systems. The multi-generation systems are the integration of a combined gasification gas turbine cycle, double flash geothermal cycle, and proton exchange membrane cycle for the generating power and hydrogen. The overall system and its subsystems are studied to explore how the performance of thermodynamics and the total cost rate are influenced by operating parameters. The best operational conditions for both subsystems and the overall system have been determined by analyzing the impact of operating parameters on the thermodynamic behavior and environmental impact through parametric studies. The findings indicate while Sabalan's current efficiency is 16.26 %, the system energy efficiency reached 24.89 % when coupled with other renewable source. To enhance the system's efficiency, a genetics algorithm was utilized to simultaneously optimize the total cost of exergy destruction and investment cost. The outcome of the multi-objective optimization revealed that the exergy efficiency of optimal point for the system is 29.8 % and a total investment cost is 6 (M$/year).

Multi-aspect evaluation of a novel double-flash geothermally-powered integrated multigeneration system for generating power, cooling, and liquefied Hydrogen

An integrated renewable geothermal-driven multigeneration system is demonstrated in the present evaluation, consisting of a double-flash geothermal unit, a modified dual-pressure organic Rankine cycle, a Proton exchange membrane electrolyzer, and a Claude Hydrogen liquefication subsystem. The proposed system is examined from various standpoints, and the performance of the system is quantified through the output parameters. Besides, a case study is performed to evaluate the operation of the system in a specified state. Moreover, a sensitivity analysis is conducted to follow the behavior of the system under different conditions. Furthermore, a multi-objective particle swarm optimization algorithm is employed to define the optimum solutions. The results of the study bring out a total generated cooling load of 2.27 MW, a net output power of 10.48 MW, and a liquefied Hydrogen rate of 37.83 kg/h. Also, exergetic efficiency and exergy destruction rate values of 55.89 % and 9.39 MW are obtained, respectively. The exergoeconomic and exergoenvironmental outputs are discussed through a total cost rate of 482.62 $/h, a payback period of 3.27 years, and a product exergy-related environmental impact rate of 9.84 Pts/h.