Thermo-economic Assessment Research Articles

Corrigendum to “A multi-energy production system utilizing an absorption refrigeration cycle, and a PEM electrolyzer powered by geothermal energy: Thermoeconomic assessment and optimization” [Renew. Energy, (229), August 2024, 120744]

Corrigendum to “A multi-energy production system utilizing an absorption refrigeration cycle, and a PEM electrolyzer powered by geothermal energy: Thermoeconomic assessment and optimization” [Renew. Energy, (229), August 2024, 120744]

Optimization of a Biomass-Based Power and Fresh Water-Generation System by Machine Learning Using Thermoeconomic Assessment

Biomass is a viable and accessible source of energy that can help address the problem of energy shortages in rural and remote areas. Another important issue for societies today is the lack of clean water, especially in places with high populations and low rainfall. To address both of these concerns, a sustainable biomass-fueled power cycle integrated with a double-stage reverse osmosis water-desalination unit has been designed. The double-stage reverse osmosis system is provided by the 20% of generated power from the bottoming cycles and this allocation can be altered based on the needs for freshwater or power. This system is assessed from energy, exergy, thermoeconomic, and environmental perspectives, and two distinct multi-objective optimization scenarios are applied featuring various objective functions. The considered parameters for this assessment are gas turbine inlet temperature, compressor’s pressure ratio, and cold end temperature differences in heat exchangers 2 and 3. In the first optimization scenario, considering the pollution index, the total unit cost of exergy products, and exergy efficiency as objective functions, the optimal values are, respectively, identified as 0.7644 kg/kWh, 32.7 USD/GJ, and 44%. Conversely, in the second optimization scenario, featuring the emission index, total unit cost of exergy products, and output net power as objective functions, the optimal values are 0.7684 kg/kWh, 27.82 USD/GJ, and 2615.9 kW.

A novel geothermal system combined with fuel cell and hydrogen generation to store clean sustainable energy storage

This paper presents a thermo-economic assessment of a novel geothermal integrated system enhanced by a fuel cell. The proposed system leverages the advantages of geothermal energy resources, featuring a sustainable and environmentally friendly solution for power generation and district heating applications. Integrating a fuel cell and thermoelectric within the geothermal system aims to improve overall system performance and energy efficiency by converting waste heat into electricity. A detailed mathematical model of the integrated system is developed, incorporating various performance parameters, component efficiencies, and thermo-economic considerations. The model is applied to simulate the system's performance under different operating conditions and parameters. Additionally, sensitivity analyses are conducted to evaluate the effects of key design variables on the system's performance, cost, and environmental impacts. The results indicate that the newly developed system generates 95594 kW of electricity with a total exergy destruction rate of 4616 kW. The electricity cost rate also obtained 0.309 $/kWh. The energy efficiency of the introduced system is 24.08 % and the exergy efficiency is 26.7 %. Comparison with the basic system represents that energy efficiency shows a 15.71 % improvement.

Comparative study of an innovative coldly integrated pumped thermal electricity storage system: Thermo-economic assessment and multi-objective optimization

Energy storage is an important means of solving the instability of renewable energy sources. As a novel energy-storage technology, thermally integrated pumped thermal electricity storage systems have gained considerable attention owing to their capacity to enhance the power-to-power efficiency of pumped thermal electricity storage systems by integrating low-grade heat sources. However, previous studies have predominantly focused on the integration of low-grade heat sources during the charging phase. In this paper, a novel coldly integrated pumped thermal electricity storage system that integrates liquefied natural gas on the discharge side is proposed. Seawater and R1233zd(E) were utilised as the system’s heat source and working fluid, respectively. The performance of the proposed system was compared with that of a previous thermally integrated pumped thermal electricity storage system that used geothermal energy as the heat source on the charge side. System models were constructed in MATLAB, and thermodynamic and economic comparative analyses were conducted. The Genetic Algorithm was adopted for the multi-objective optimisation of the two systems. The results indicate that, within given temperature ranges for thermal and cold storage temperatures, the proposed system exhibits a higher power-to-power efficiency and has a lower levelised cost of storage compared to the existing system. The optimal power-to-power efficiency and levelised cost of storage solutions obtained via multi-objective optimisation were 1.45, 0.297 $·kWh−1 and 0.807, 0.411 $·kWh−1 for the coldly integrated and thermally integrated pumped thermal electricity storage systems, respectively. The proposed system outperformed the thermally integrated pumped thermal electricity storage system under comparison in terms of thermodynamic and economic performance. The findings of this study shed light on the design and performance of coldly integrated pumped thermal electricity storage systems.

Thermo-economic assessments on building heating by a sewage source heat pump coupled with heat storage system

To enhance the economic feasibility of building heating systems, phase change heat storage materials are often utilized to utilize renewable energy and address system peak loads. This article presents an innovative method of integrating a sewage source heat pump with a heat storage device. Upon an industrial building in Xilinhot as a case study, numerical models for the heat accumulator coupled with the energy consumption of buildings are established, taking into account dynamic hourly loads and meteorological conditions. Through a comprehensive analysis, the thermophysical properties of the heat accumulator as well as the economic implications of the multi-energy complementary heating system are investigated. Results demonstrate that the complete melting time for a 95 % filling rate is significantly reduced, 87.11 % shorter than that of pure phase change material, achieving the highest heat storage efficiency. Furthermore, the phase change storage device with a 75 % filling rate had the shortest investment payback period, requiring only 6 years. These findings have significant implications for guiding green renovation projects in building heating systems.

Solar-Powered Combined Cooling, Heating, and Power Energy System with Phase-Change Material and Water Electrolysis: Thermo-Economic Assessment and Optimization

Solar-Powered Combined Cooling, Heating, and Power Energy System with Phase-Change Material and Water Electrolysis: Thermo-Economic Assessment and Optimization

Investigation of low-GWP working fluids as substitutes for R245fa in organic Rankine cycle application

This study presents a thermo-economic assessment of three low-global-warming-potential (GWP) substitutes, R1233zd(E), R1234ze(Z) and R1234ze(E), for R245fa used in organic Rankine cycle (ORC) systems, considering two models with different heat sources. The exhaust heat from a diesel generator is served as heat source of Model I, while the waste heat of exhaust and jacket cooling water are used as heat source of Model II. It is noted that the working pressure of R1234ze(E) is much higher than that of R1233zd(E), R1234ze(Z) and R245fa in a fixed evaporation-temperature range. Furthermore, the system using R1234ze(E) has the minimum net power output for Model I, while it turns into the maximum net power output for Model II. In addition, both R1234ze(Z) and R1233zd(E) can be used as good alternative working fluids for R245fa because R1234ze(Z), R1233zd(E) and R245fa have close working pressures, maximum net power outputs, and minimum levelized energy costs. Compared to Model I, LECmin of R1233ed(E) and R1234ze(Z) are reduced by 10.8 % and 9.9 % and PBmin of R1233ed(E) and R1234ze(Z) are reduced by 11.5 % and 10.1 %, respectively, in Model II. However, R1233zd(E) has the highest minimum payback period for both Model I and Model II among the four working fluids investigated.

Thermoeconomic assessment of the air-cooled tropical data center through energy-saving strategies

Rapid developments in the electronic information industry drive the increased energy usage and carbon emission of data center buildings, prompting the focus on the energy efficiency and environmental sustainability. Expanded operation envelopes of tropical data centers is assessed to analyze the potential for the building energy savings and carbon emission reduction through collaborative analysis of operation modes (OMs), supply air temperature (SAT), and outdoor air temperature (OAT). The OMs of compression vary with the setpoints of SAT, in which the average exergy efficiency of compressors at alternate operation mode is 6.8 % and 8.0 % lower than that of double and single compression operations. As SAT rises from 20 °C to 32 °C, the system exergoeconomic factor increases from 5.4 % to 8.0 %, and the average carbon cost decreases by 36.5 %. Additionally, with just an 8.5 % increase in exergy cost (i.e., Case 8) at OAT rising from 30 to 34 °C, the high SAT and low refrigerant charges provide considerable exergy cost advantages versus resisting the OAT fluctuations. Dynamic operation strategies are also proposed and compared to cope with the impacts of tropical environments. Compared to the 26 °C SAT baseline, the average energy savings are 9.1–14.7 %, indicating the ability to fully utilize outdoor and indoor conditions.

A multi-energy production system utilizing an absorption refrigeration cycle, and a PEM electrolyzer powered by geothermal energy: Thermoeconomic assessment and optimization

This study aims to optimize a multi-energy production system that utilizes sustainable geothermal energy as its primary power source. The system comprises several subsystems, including a geothermal well, an organic rankine cycle (ORC) unit, an absorption chiller, and a proton exchange membrane (PEM) electrolyzer. The study examined the impact of variations in seven key parameters, including turbine inlet temperature, evaporator pinch point temperature, pump inlet temperature, evaporator inlet temperature, evaporator inlet mass flow rate, turbine efficiency, and pump efficiency, on the overall system performance. The Response Surface Methodology (RSM) was employed to find the optimum point of the system. To facilitate the practical implementation of the system, the research team assessed its viability in 10 different Iranian cities, all known for their substantial geothermal energy potential. Among the cities, Zahedan emerged as the most suitable location for deploying the system, given its robust energy production potential. The results showed that January, with a production of 626.4 MW h of electricity, and November, with a production of 622.8 MWh of electricity, are the best months for the system to operate in Zahedan city. The environmental aspect of the system also yielded noteworthy results. By setting up the proposed system in Zahedan city, it is possible to prevent the emission of 1472.411 tons of carbon dioxide by producing 7217.7 MWh of electricity throughout the year at a cost of 35337.86 $. Additionally, the proposed system can help expand 7 ha of green space, providing the electricity needed by 2349 people throughout the year.

Proposal of a geothermal-driven multigeneration system for power, cooling, and fresh water: Thermoeconomic assessment and optimization

The depletion of fossil fuel reserves and environmental challenges have prompted the exploration of alternative energy sources. Geothermal energy, extractable from within the Earth's crust, emerges as a reliable renewable option throughout the mentioned shift. In this regard, the presented study introduces a geothermal-powered multigeneration system designed to generate power, manage cooling loads, and produce fresh water. This comprehensive system incorporates an organic flash cycle, a half-effect absorption refrigeration unit, a Kalina cycle, and a humidification-dehumidification desalination unit. Evaluating the system's thermoeconomic performance involves considering input parameters and simplifying assumptions to determine the performance profitability of the presented system. Furthermore, a parametric examination is conducted which is followed by the employment of an optimization analysis across three diverse scenarios to identify the most favorable operating conditions. The results of the presented research reveal that the suggested system can deliver power, cooling capacity, and freshwater production at rates of 342.3 kW, 301.7 kW, and 0.233 kg/s, respectively. Additionally, the system demonstrates an exergy efficiency of 31.52 % and achieves a payback period of 5.85 years.

Thermo-economic assessment of a salt hydrate thermochemical energy storage-based Rankine Carnot battery system

Carnot batteries are critical technologies for increasing the penetration of renewable energy sources because they enable suitable energy storage for long-term periods. The achievement of high efficiencies is an important point that determines the sustainability of the Carnot batteries. In this direction, a novel Rankine Carnot battery with heat upgrading capability based on salt hydrate thermochemical energy storage is proposed herein. The steady thermodynamic and economic models for the basic Carnot battery and recuperators introduced Carnot battery, both with a storage capacity of 10 MW/5h, have been established. The thermo-economic performance of the Carnot battery systems and the effects of several key parameters are quantitatively assessed. Results manifest that the Carnot battery with recuperators behaves better in comprehensive performance thanks to the heat recovery by recuperators. The power-to-power efficiency, exergy efficiency, and levelized cost of storage for the basic Carnot battery and recuperators introduced Carnot battery systems are 48.48 %, 38.48 %, 0.2502 $/kWh and 64.1 %, 48.94 %, 0.1922 $/kWh, respectively. The maximum exergy destruction occurs in the heat exchanger for the Carnot battery systems and the throttle's exergy destruction is diminished by 70 % in the recuperators introduced Carnot battery. The compressor and turbine account for the largest cost ratios, i.e., 26.5 % and 24.8 % in the basic Carnot battery and 28.2 % and 27.2 % in the recuperators introduced Carnot battery; while the cost proportion of throttle in both systems is nearly ignorable (0.3 %). Elevating heat source temperature and the reactant's hydration temperature and descending ambient temperature contribute to the improvement of power-to-power efficiency and levelized cost of storage. The isentropic efficiencies of compressor and turbine, especially the latter, have a great impact on the thermo-economic performances. As the daily charging time expands to 7 h, the levelized cost of storage of the recuperators introduced Carnot battery reduces to 0.1434 $/kWh. Replacing the reactive salt of potassium carbonate sesquihydrate (K2CO3·1.5H2O) with magnesium sulfate tetrahydrate (MgSO4·4H2O) brings a lower levelized cost of storage of 0.18 $/kWh. The findings of this study demonstrate great potential for the exploitation of this thermochemical energy storage-based Carnot battery for large-scale electricity storage.

Thermoeconomic Analysis of a Compact Active Coolant System for Lithium-Ion Battery Pack

The present work aims to perform a thermoeconomic assessment of a battery pack integrating a novel compact coolant system through which Al2O3, TiO2, CuO, and Cu nanofluids flow at different Reynolds numbers and concentrations. The inlets in the north and west and the outlets in the south and east directions are found to be the best configuration since the least number of batteries exhibits higher temperatures. A nanofluid-based cooling system offers an improvement of 15 K in battery core temperature when compared to the pack without any coolant system at 200 s; however, a reduction of 0.3 K is noticed when compared to water. CuO nanoparticles perform better at a low concentration of 2%, whereas Cu particles have an advantage over other nanoparticles at a concentration greater than 2%. An economic analysis of the nanofluid has also been performed, eradicating the idea of using Cu–water nanofluid in the coolant system owing to its significantly high cost. Though the cost of the CuO and Al2O3 nanofluid is 13 times lower than Cu, using pure water as the coolant is recommended since there is a marginal reduction of 0.1–0.3 K in the battery pack temperature when water is replaced by nanofluid.

Thermo-economic assessment of a combined cooling and heating system with energy storage device

Large cold chain and food processing enterprises simultaneously require both high-temperature hot water and low-temperature quick freezing capabilities. To achieve an efficient and cost-saving solution of cooling and heating supply with waste heat recovery in the food processing, a novel combined cooling and heating supply system with energy storage (CCHES) is proposed. In this novel system, a cascade heat pump cycle is used to product the hot water with 100 °C for thermal food processesand a cascade absorption-compression refrigeration cycle is used to recover the waste heat from hot wastewater during the food processing and provide the cooling capacity with −30 to −50 °C for deep freezing. A hot water tank is added in this novel system for energy storage. A thermo-economic model is developed to analyze the thermodynamic performances and economic advantages of this novel system and an optimization is conducted by discussing parameters effects including the generator temperature and two kinds of evaporation temperatures. The results show that the optimal middle temperature is 10 °C, which cannot be impacted by two evaporation temperatures. Additionally, the corresponding optimal SENE, COPACS and ECOP are 1.35, 1.78 and 0.284. The CCHES recovers waste-heat capacity accounting for 96.1 % of provided heating capacity. The total cost of CCHES within 25 operation years is 8.33 × 106$, inducing savings of 3.2 × 105$ compared to the total cost of a system without energy storage device.

Thermo-economic assessment and multi-objective optimization of organic Rankine cycle driven by solar energy and waste heat

An organic Rankine cycle (ORC) power generation system driven by integrated solar energy and waste heat is proposed based on the concept of multi-energy complementarity. Three types of solar collectors, two different heat source integration schemes and nine different candidate organic fluids are studied and compared. The effects of main operating parameters on thermo-economic performance are analyzed. A multi-objective optimization framework with a competitive mechanism based multi-objective particle swarm optimizer (CMOPSO) as the core is constructed and the system is optimized. The results of the multi-objective optimization guide the design of the multi-heat source ORC and the selection of the working fluid. When the temperature difference between two heat sources is greater than 50 °C, the heat exchangers are recommended to be connected in series for better overall performance. Besides, the series scheme favors the working fluid with a higher critical temperature, whereas the working fluid with a lower critical temperature is appropriate for the parallel scheme.

Optimization and thermo-economic assessment of hemispherical solar distillers with a flat and concave basin: Experimental approaches

One of the challenging issues facing the world today is a lack of clean drinking water. The straightforward and efficient solution to this problem is the use of solar stills, which is one of the solar desalination methods that use renewable energy. The design selection of the solar stills is one of the strategies for distillate optimization, which aims to increase the productivity of solar distillates. To achieve this idea, this study deals with a comparative performance analysis of two solar stills with the same hemispherical cover, one contains a flat basin and the second contains a concave basin. Two hemispherical solar distillers, one of which has a flat basin (HSD-FB) and the other has a concave basin (HSD-CB) were designed and tested in El Oued, Algeria, under the same climatic conditions to get the better design of basin solar distillers. The results showed that the concave basin represents the best design that achieved the highest performance of hemispherical solar distillers. The daily productivity of the hemispherical solar distiller with a concave basin (HSD-CB) reached 5.50 kg/m3 with an improvement of 23.59% compared to HSD-FB. Also, with the utilization of the concave basin (HSD-FB), the daily thermal efficiency increased from 37.69% to 46.43% with an improvement of 23.19% compared to HSD-FB.

Comparative thermoeconomic assessment of renewable-driven hybrid-cooled sustainable greenhouses for subtropical regions

The rapid population growth in subtropical regions and heavy reliance on food imports have led to many countries facing food insecurity. In subtropical regions, the combination of high ambient temperatures, intense solar radiation, lack of fertile soil, and limited freshwater resources create an inadequate environment for agriculture production. Without sustainable and innovative solutions, cultivation in subtropical regions will become energy-intensive, expensive, and susceptible, if not entirely unattainable. Therefore, this research work delves into assessing the thermoeconomic performance of 10 renewable-driven hybrid-cooled greenhouse integrated systems based on different solar power generation technologies, cooling cycles, and desalination systems. Four greenhouse configurations are simulated: Closed greenhouse, shaded greenhouse, buried greenhouse, and buried and shaded greenhouse. Firstly, passive cooling techniques' potential to reduce active-cooled greenhouse cooling demand and water usage was investigated, taking into account the need to provide crops with adequate environmental temperature, solar irradiation, and ventilation. Secondly, a detailed thermodynamic analysis was conducted to obtain the overall energy and exergy efficiencies of the investigated greenhouse integrated systems. Thirdly, a comparison of solar panels area requirement for the greenhouse integrated systems was performed. Finally, a comprehensive life cycle cost analysis of the examined integrated systems for the hybrid-cooled greenhouses was done to compare their economic performance. The results showed that the adopted passive cooling methods reduced yearly cooling load by 34.2–58.1%, evapotranspiration during maximum cooling load day by 17.4–34.1%, solar panels area by 8.5–32.1%, and integrated systems' life cycle cost by 5.6–28.6%. Greenhouse integrated systems powered by photovoltaic panels obtained the lowest life cycle cost, while greenhouse integrated system-4 driven by concentrating photovoltaic thermal panels was found superior in terms of panels area.

Thermo-economic assessment and optimization of an innovative tri-generation system using supercritical CO2 power system and LNG cold energy recovery

The present study introduces a novel tri-generation system that is highly efficient and cost-effective, employing a supercritical CO2 (sCO2) Brayton cycle as the primary mover and harnessing the cooling potential from liquefied natural gas (LNG) as a heat sink. This innovative system simultaneously provides electricity, cooling, and hydrogen. By capitalizing on the substantial temperature difference between the high-temperature sCO2 power cycle and the low-temperature LNG cold source, an integrated combination of the Kalina cycle (KC) and organic Rankine cycle (ORC) is utilized. Additionally, the system incorporates a proton exchange membrane electrolyzer (PEME) and an absorption refrigeration cycle (ARC) to create a highly efficient trigeneration system. The system is rigorously evaluated through energy, exergy, and exergoeconomic analyses, which are critical for assessing performance. Additionally, this study conducts a parametric investigation to elucidate the impact of key parameters on system performance. Furthermore, optimization is performed using a genetic algorithm (GA), with the objective of maximizing energy and exergy efficiencies or minimizing the overall product cost. Results from the baseline scenario demonstrate impressive energy and exergy efficiencies of 54.38 % and 59.46 % respectively, along with a low total product unit cost of 11.642 ($/GJ), outperforming existing benchmarks in the literature. The system also provides substantial net power output, cooling capacity, and hydrogen production rates of 276.71 MW, 60.19 MW, and 176.25 kg/h, respectively. This combination of high performance and cost-effectiveness makes the proposed system a versatile choice, underscoring its significance in sustainable and environmentally friendly energy solutions.

Thermo-economic assessment of air conditioner utilizing direct evaporative cooling: A comprehensive analysis

As concerns regarding energy consumption and environmental impact continue to grow, the need for efficient and sustainable cooling technologies becomes increasingly significant. Among various alternatives, direct evaporative cooling (DEC) has emerged as a promising solution due to its energy-efficient operation and low environmental footprint. This paper aims to provide a comprehensive thermo-economic assessment of a 5.25 kW capacity split air conditioner (SAC) integrated with direct evaporative cooling, focusing on evaluating its performance, energy consumption, coefficient of performance(COP), and economic viability. A numerical model is developed to determine the reduction in the condenser inlet air temperature due to direct evaporative cooling. The ambient temperature (30–45 ⁰C), relative humidity (20–80 %), and evaporator temperature (3–12 ⁰C) are taken as the design variables. Box–Behnken design (BBD) technique of response surface methodology is applied for multi-objective optimization. The COP, total cost rate (TCR), and total exergy destruction (E˙D,t) are set as the objective functions. Cooling capacity, life period, operation time, interest rate, maintenance factor, and electricity cost are taken as constants. The thermoeconomic optimization evolved maximized COP enhancement of 68.94 %, and reduction in TCR and ED,t by 26.12 % and 57.23 %, respectively. The water consumption to energy saving ratio varies from 5.5 to 9.8 L/kWh for different months of the cooling season. The thermoeconomic performance and sustainability of DECSAC is observed to significantly improve compared to conventional SAC specifically in hot-dry climates. The simple payback of the proposed system ranges between 1.21 to 2.99 years depending upon the operating conditions.

Exergoenvironmental optimization and thermoeconomic assessment of an innovative multistage Brayton cycle with dual expansion and cooling for ultra-high temperature solar power

In the background of energy scarcity and environmental pollution, solar power towers confront challenges of low conversion efficiency, high electricity price, and severe relative environmental impact difference. For that, this study develops an innovative multistage Brayton cycle for ultra-high temperature solar power based on the basic Brayton cycle. Primarily, a series of tasks are performed sequentially, including the development and validation of mathematical models for each subsystem and innovative multistage Brayton cycle, the exploration of conversion potential, the analysis of operational parameters, and the comparison of structural advancement. After optimization, the thermoeconomic and exergoenvironmental performances of each subsystem and component under optimal operational condition are exhaustively discussed. Ultimately, the operational characteristics of the innovative multistage Brayton cycle are comprehensively assessed. The optimized exergy efficiency, electricity price, and exergoenvironmental factor are 25.92 %, 0.1089 $/kWh, and 74.71 %, respectively, representing an improvement of 4.95%–8.56 % in solar-to-electricity efficiency compared to similar research. This system efficiently converts solar energy under designed operational conditions, with excellent thermodynamic performance, economic benefit, and environmental friendliness, and meets the requirements of the carbon neutral policy as well as energy saving and emission reduction.

Thermo-Economic Assessment of Advanced Triple Cascade Refrigeration System Incorporating a Flash Tank and Suction Line Heat Exchanger

Thermo-Economic Assessment of Advanced Triple Cascade Refrigeration System Incorporating a Flash Tank and Suction Line Heat Exchanger