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This article aims to examine a novel combined power and refrigeration system, using renewable and waste heat sources suitable for low-temperature applications. The present system is an integrated Kalina cycle and ejector refrigeration system to generate power and refrigeration simultaneously. To improve the vapour generation, the separator vapour fraction is used as a decision variable. Relative irreversibility and efficiency defect as two important parameters considered in this system for an investigation to identify the weaker components. The combined system generates power and refrigeration with two different mediums by the incorporation of the heat exchanger at the turbine exhaust. The novel system's energy and conventional exergy evaluation are carried out through Python Software. The optimum values of decision variables: turbine concentration, separator vapour fraction, entrainment ratio, expander ratio, split ratio and turbine concentration are identified using Python software from an opted range of variables. The maximum value of net power output, first law efficiency for power generation system, combined system, second law efficiency for power generation system, combined system, refrigeration effect and coefficient of performance are obtained as 113 kW, 8.85%, 11.83%, 93.44%, 81.29%, 38.07% and 0.118, respectively, at higher separator vapour fraction. Among the components considered in the combined power generation system, the condenser and LTRGN account for the higher exergy destruction rate of 30.41% and 25.53%. The coefficient of performance is maximized at a higher value of the refrigeration effect. The turbine pressure at the inlet is increased with increments in turbine work on choosing the higher value of the expander ratio. The higher exergetic value components are not emphasized to focus on improvement. [ABSTRACT FROM AUTHOR]

The lack of freshwater in many countries pushes authorities to utilize desalination units. Solid Oxide Fuel Cells (SOFC) have shown promising results to provide the power to establish a multi-generation system using hydrogen as a renewable source. In this article, to better improve the efficiency of the suggested integrated system, the waste heat of the SOFC is recovered through the application of a Kalina power cycle and Humidification-dehumidification (HDH) desalination unit. Liquefied Natural Gas (LNG) cold stream also utilizes the waste heat of the Kalina cycle (KC) to provide cooling and power simultaneously. As all the considered cycles of Kalina, LNG cold stream, and SOFC can produce power and as this amount of electricity would be higher than the grid's demand, a further Reverse Osmosis (RO) desalination unit is utilized to increase the output amount of freshwater in the proposed system. The main focus of this study is to perform the thermodynamic analysis of this tri-generation system, which can generate power, cooling, and freshwater. Results indicate that the exergy and energy efficiencies of the current suggested system when the current density of the SOFC is 550 (A/ m 2), is around 55% and 60%, respectively. • Suggesting a novel system to produce freshwater, electricity, and cooling. • Thermodynamic analysis of the proposed novel tri-generation system. • Having energy and exergy efficiencies of 60% and 55%, respectively. • Parametric study considering the changes in the SOFC's current density. [ABSTRACT FROM AUTHOR]

This article introduces a novel multiple-cycle generation system for efficient heat recovery at high and low temperatures. The system is modeled and optimized using the M2EP analysis method (mass, energy, exergy, and performance) and the particle swarm optimization algorithm. The multigeneration system produces electricity, cold, domestic hot water, and biogas by utilizing Kalina cycles, diffusion–absorption refrigeration machines, and high-performance heat exchangers by harnessing waste heat from cement kiln exhaust gases. The Kalina cycle is employed for electricity generation, wherein the H2O+NH3 mixture, heated by hot water, circulates through heat exchangers. Downstream of the Kalina cycle, the refrigeration machine generates cold by evaporating the strong solution of the H2O+NH3 mixture. Hydrogen circulates in the diffusion–absorption refrigerator (DAR) circuit, facilitating the exchange between the evaporator and the absorber. The domestic hot water and biogas production systems operate at lower temperatures (around 45 °C). The simulation results for the Kalina cycle indicate an electrical energy production of 2565.03 kW, with a release of usable energy (residual gases) estimated at 7368.20 kW and a thermal efficiency of 22.15%. Exergy destruction is highest at heat exchanger 1, accounting for 26% of the total. A coefficient of performance of 0.268 and an evaporator temperature of 10.57 °C were obtained for the DAR cycle. The absorber contributes the most to energy exchanges, comprising 37% of the entire circuit. Summarizing the potential for valorizing waste heat from cement kilns, this article lays the foundation for future research. [ABSTRACT FROM AUTHOR]

The Kalina cycle is well-known for its innovative energy conversion optimization, utilizing various working fluids such as butane, freon, isobutane, and pentane to evaluate efficiency and performance. This research explores the interaction of fluids in the Kalina cycle to enhance heat recovery by utilizing heat from road infrastructure. Our research focuses on analyzing thermodynamic intricacies and fluid dynamics to provide insights for improving sustainable energy technologies and enhancing heat utilization in various industrial applications. The performance of working fluids in the Kalina cycle has a notable impact on power generation or consumption, which can differ depending on the equipment configurations. One interesting observation is that certain cycles showed a net energy gain at the turbine, particularly the ammonia cycle running at 75 % working fluid, which generated a total net power of −1030.6048 kW. Two freon cycles were compared in terms of net power output: the pure freon cycle produced −125.493 kW, whereas the freon cycle with 90 % freon generated −375.1616 kW. Finally, the pentane cycle with a 50 % efficiency yielded a net power output of −137.6613 kW. This study offers a thorough understanding of how working fluids perform in the Kalina cycle, which can help improve energy conversion processes and promote sustainable energy solutions.

This study proposes a novel methodology for optimizing the Kalina Cycle System-34, providing new insights into the existing literature on the cycle. The research highlights the cycle's key variables and identifies the most critical parameters that require improvement while proposing a practical and effective optimization method. The effects of parameters on thermal and exergy efficiency were quantified using Taguchi and ANOVA methods. The study focuses on critical parameters such as evaporator outlet temperature, turbine inlet pressure, ammonia concentration, turbine efficiency, and pump efficiency. The optimal values of these parameters were determined within specified ranges. Furthermore, the study employed the L25 orthogonal array to create case scenarios that reduced the computational cost of the Kalina cycle. The best-case scenario was not included in the 25 cases in the orthogonal array, which significantly reduced computational costs. The results showed that the system's thermal efficiency increased to 16.2 %, and exergy efficiency increased to 27.8 %, with the case conditions for the best case being an evaporator outlet temperature of 120 °C, ammonia concentration of 0.9, turbine inlet pressure of 40 bar, turbine efficiency of 0.9, and pump efficiency of 0.8.

ABSTRACTDemand for electricity and cooling is increasing due to population growth, which in turn increases pollution. Renewable energy sources are gaining popularity due to their lower levels of pollution. Resource utilisation efficiency is an important factor in maximising the efficiency of low-temperature heat sources. In this study, a vapour absorption cooling cycle and a Kalina power cycle were merged. At the economiser, heat is recovered from the heat exchanger and divided into two basic solution streams. The high-pressure flow passes through the boiler evaporator to produce wet steam, while another stream is throttled to an intermediate pressure. The thermal efficiency of the cycle improves with increasing separator temperature, separator pressure, concentration, and heat recovery temperature, but there is an optimal separator temperature for resource utilisation capacity. Increasing separator pressure and heat recovery temperatures improves resource utilisation efficiency. The proposed cycle has a better temperature match in the heating process. The resource utilisation efficiency of the present cycle is 31.13%, which is 90.63% higher than the reference study.

To assess the electricity cogeneration potential in the Minas Gerais cement industry with thermodynamic cycles is the main purpose of this study. The potential was estimated based on Minas Gerais cement sector data. The Kalina cycle, the organic Rankine cycle, and the conventional Rankine cycle were technically and economically assessed. The technical evaluation considered the thermodynamic modeling with optimization including the mass, energy, entropy, and exergy balances and the heat transfer calculations for heat exchangers. The economic evaluation considered the economic modeling including the calculation of electric power generated specific cost, the total investment, cash flow, and payback. The result shows that the greatest irreversibilities are concentrated in the turbines and evaporators. The Kalina cycle confirmed more generated power and exergetic efficiency, but in terms of thermal efficiency, the values were very similar between the cycles. The three cycles can cover more than 35% of the energy demand, which means a considerable reduction in cement manufacturing costs. All cycles reveal a payback value lower than 3 years, a considerable value of cash flow, and high competitiveness in the current tariff scenario. The electricity cogeneration potential in the Minas Gerais cement industry is near 100MW, and it is in the south-central region of Minas Gerais, where there is a greater population and energy demand concentration. This potential could save emissions of around 282,913 tCO2/year. [ABSTRACT FROM AUTHOR]

The primary focus of this review article is to examine the power cycles employed for generating electricity from steam-dominated resources. It discusses the phenomenon of Transcritical CO2 (T-CO2) power cycles and the Rankine Cycle, which have been extensively studied by numerous academics. The article also briefly explores fuel-cell-based power plants using binary cycles, geothermal power plants, and solar-assisted power plants. The article presents information on power generation, thermal efficiency, energy efficiency, and exergy efficiency of these plants. The investigation reveals that geothermal power plants have thermal efficiencies ranging from 6.5% to 16.63% and exergy efficiencies ranging from 7.95% to 82%, producing power in the range of 199.1 kW to 19,448 kW. Solar power plants produce power ranging from 550.9 kW to 4500 kW, with energy efficiency between 21.93% and 57% and exergy efficiency between 50.5% and 64.92%. Fuel cell power plants using NH3+H2O as the working fluid generate power from 1015 kW to 20125 kW, with thermal efficiency between 25.4% and 70.3% and exergy efficiency between 12.1% and 36%. The article highlights the use of the Kalina cycle in these scenarios. [ABSTRACT FROM AUTHOR]

There has been an increasing interest in solar-driven combined energy supply systems for low-temperate applications, particularly those based on the Organic Rankine Cycle (ORC), Kalina Cycle (KC), or Trilateral Cycle (TLC). However, systems based on these thermodynamic cycles usually employ large area collectors that stand alone or are placed on the roof, without considering integration with the building facade. This research presents a solution to large-scale photothermal utilization integrated with facades for co-generated systems. The current study is the first to conduct performance and economic assessment for four novel solar cooling and power (SCP) co-generated systems driven by evacuated tube solar collectors (ETCs) or semi-transparent photovoltaic (STPV) integrated into the building facades. The suggested systems were simulated using TRNSYS to forecast their performance metrics when used in four Chinese cities with various climate zones. As indicators, a solar fraction (SF) and unit energy cost (UEC) were used to evaluate the technical and financial aspects of each system. The STPV-vapor compression cycle (VCC) system had the highest SF (100%, except Haikou), as well as the lowest UEC (0.211$/kWh on average) among the four cities, according to the results. Among the three solar-thermal co-generation systems, ETC-ORC-VCC had the best performance (SF,37.9%; UEC,0.597$/kWh on average). [ABSTRACT FROM AUTHOR]

Combination of different power cycle scenarios is of prime importance in achieving maximum energy utilization from solar‐driven multigeneration systems. To fulfill such objective, the present article proposes a novel energy distribution system, leveraging a combination of direct‐fed organic Rankine cycle (ORC) and a bottom‐cycled arrangement of Kalina cycle system (KCS) and double‐effect absorption refrigeration cycle (DEARC) within a parabolic trough solar collector powered trigeneration system. The study explores three different ORC configurations: simple ORC; ORC equipped with internal heat exchanger (ORC‐IHE) and regenerative ORC (RORC). It is shown that although higher efficiencies are achievable from a larger portion of PTSC energy absorbed by the ORC, the ORC energy absorption is limited by ORC evaporator temperature differences, and there is unused energy that can be recovered by the KCS, based on the proposed energy system. The results indicate that the addition of bottoming KCS leads to a considerable increase in the exergy efficiency of ORC, ORC‐IHE and RORC‐based systems by 11.7%, 30.7% and 32.6%, respectively. The impact of different ORC configurations, key ORC parameters and various organic working fluids on the energetic/exergetic efficiencies is also examined to find the optimal configuration. In terms of overall energetic/exergetic efficiencies, the highest performance belongs to ORC (78.4%/30.4%) while the lowest energetic and exergetic efficiencies belong to ORC‐IHE and RORC, respectively (56.3% and 25.65%). On the basis of a comparative study with the available literature, these values are higher than what is already reported for similar solar‐driven multigeneration systems. Appropriate thermal match and lower exergy destruction in the KCS, and bottoming cycle arrangement of the DEARC are the main reasons for such enhanced performance. This research not only contributes valuable insights into efficient solar‐driven systems but also sets a new benchmark for performance metrics in the existing literature. [ABSTRACT FROM AUTHOR]

This paper proposes a novel solar-based polygeneration system for simultaneous power generation, desalination, hydrogen-production, and refrigeration. The system integrates parabolic trough solar collectors, multi-effect distillation, polymer electrolyte membrane electrolyzer, Kalina cycle, organic Rankine cycle, Brayton cycle, and ejector cooling. Solar energy and waste heat from the Brayton cycle provide energy input. Power generation is achieved via the Brayton, Kalina, and organic Rankine cycles. The multi-effect distillation unit produces freshwater while the electrolyzer generates hydrogen. The ejector system supplies cooling. A comprehensive steady-state energy and exergy analysis evaluates the thermodynamic performance. The system attains 32.269 MW net power output and ejector COP of 0.3193. The overall energy and exergy efficiencies are 38.45% and 35.64%, respectively. The combustion chamber exhibits maximum exergy destruction. Exergoeconomic analysis determines associated costs and investment feasibility. Integrating multiple technologies into a system with solar input enhances efficiency, sustainability, and environmental benefits. • Presents novel solar multi-generation system integrating power, hydrogen, water and cooling generation • Validated methodology analyzes thermodynamic performance providing insights on efficiencies • Exergy destruction analysis identifies optimization opportunities in integrated solar systems • Showcases potential of intricate integration of solar, desalination, hydrogen and power for sustainable energy • Modular and scalable system design enables flexibility for different applications and demands [ABSTRACT FROM AUTHOR]

In this study, it is proposed to generate electrical energy by recovering the waste heat of an annealing furnace (AF) in an iron and steel plant using combined cycles such as steam Rankine cycle (SRC), organic Rankine cycle (ORC), Kalina cycle (KC) and transcritical CO2 cycle (t-CO2). Instead of releasing the waste heat into the atmosphere, the waste heat recovery system (WHRS) discharges the waste heat into the plant's low-temperature oxygen line for the first time, achieving a lower temperature and pressure in the condenser than conventional systems. The waste heat of the flue gas (FG) with a temperature of 1093.15 K from the reheat furnace was evaluated using four different cycles. To maximize power generation, the SRC input temperature of the proposed system was studied parametrically. The cycles were analyzed based on thermal efficiency and net output power. The difference in SRC inlet temperature is 221.6 K for maximum power output. The proposed system currently has a thermal efficiency and total power output of 0.19 and 596.6 kW, respectively. As an environmental impact, an emission reduction potential of 23.16 tons/day was achieved. In addition, the minimum power generation cost of the proposed system is $0.1972 per kWh. [ABSTRACT FROM AUTHOR]

Considering biogas upgrading to feed energy systems and its significant impact on the biogas energy density, a novel polygeneration system utilizing biogas from landfill waste is designed, simulated, and studied in this paper. The primary innovation is to design a biogas upgrading technology for a novel multigeneration system using a thermal matching approach. This system is capable of simultaneously generating power, providing heating, producing fresh water, and extracting liquid carbon dioxide in an environmentally sustainable manner, thus resulting in reduced environmental impacts. For this purpose, a cryogenic separation system based on liquefied natural gas cold utilization is employed for biogas upgrading and biomethane separation. The proposed process also consists of a Kalina cycle, an organic Rankine cycle, a multi-effect desalination technology, and a heating provider unit. This system is simulated within the Aspen HYSYS software and is undergone a comprehensive analysis from the viewpoints of energy, exergy, environmental, and economic. The results indicate that the proposed structure achieves energy and exergy efficiencies of 80.91% and 43.76%, respectively. Environmental assessment reveals that the emission intensity is 90.43% lower in polygeneration mode compared to power generation mode, and the system's net emission is equal to 23,041.51 kg/h. The economic evaluation demonstrates that the total unit cost of products is minimized in polygeneration operation (1.84 $/GJ), while it is highest in power generation condition (7.564 $/GJ). The investigations show that when a system is modified from a single generation to polygeneration, all thermodynamic, economic, and environmental indicators face an improvement. [Display omitted] • Design of a new trigeneration system using biogas upgrading and LNG regasification. • Sustainable scheme for producing power, heating, fresh water, and liquid carbon dioxide. • Aspen HYSYS is used for simulation and thermo-enviro-economic analysis is done. • Energy and exergy efficiencies of the whole system equal 80.91% and 43.76%. • Net emission and total unit cost of products equal 23,041.51 kg/h and 1.84 $/GJ. [ABSTRACT FROM AUTHOR]

In this paper, various thermal energy systems are studied to recover waste heat from gas turbines with different configurations. The exergy analysis and environmental examination are applied to achieve better insight into the suggested systems. Also, multi-objective optimization is employed to find the optimal condition of the introduced plants. In this work, various systems such as gas turbine (GT), organic Rankine cycle (ORC), and Kalina cycle (KC) with Proton Exchange Membrane (PEM) electrolyzer are combined to achieve a new system design. In this study, Engineering Equation Solver (V11.755) and Matlab (R2023a) software are used to simulate and optimize the proposed system. The comparison of systems shows that the combustion chamber with 3622 kW has the most considerable exergy destruction in the IGT/ORC-KC plant. The comparative investigation shows that IGT/ORC-KC has the highest output at 5659 kW, while the smallest exergy destruction is associated with the IGT system with 1779 kW. The multi-objective optimization considering three objective functions, namely, exergy efficiency, product cost, and environmental effects of exergy destruction, is conducted. Three-objective optimization on the IGT/ORC-KC unit shows that in the optimum point selected by the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) approach, the exergy efficiency, cost of product, and environmental effect of exergy destruction rate are 29.5%, 0.31 USD/kWh, and 13.22 mPt/s. [ABSTRACT FROM AUTHOR]

The current works aim is performance improvement of different integrated energy systems towards net-zero energy which is driven by a set of Internal Combustion Engine (ICE) through adding some components like fuel cell and thermoelectric generator (TEG) in new arrangements introduced and analyzed. The novelty of the present work is the proposal of the new arrangement of energy conversion systems. In this study the basic cycle (cycle 1) is including an ICE, Kalina cycle, Humidification and Dehumidification (HDH) unit, in cycle 2, the HDH is eliminated while a fuel cell is added to the system and in the cycle 3, in addition to fuel cell and having HDH unit in the system, a thermoelectric generator (TEG) has been used instead of condenser to recover more wasted thermal energy. The performance of all proposed systems is analyzed from energy, exergy, and exergo-economic aspects. It is demonstrated that from an energetic viewpoint, cycle 3 has the better performance with an energy efficiency, and net output power of 37% and 391.7 kW, respectively. That is while from an exergetic viewpoint cycle 2 with exergy destruction of 257.1 kW has superior exergetic performance. The results of current work can provide a precise basis for designing an efficient energy system with a higher thermal performance. • Performance of different integrated energy systems towards net-zero energy. • Cycle components are ICE, HDH unit, Fuel cell, Thermoelectric generator. • From energetic viewpoint, cycle 3 has the better performance. • From exergetic viewpoint, cycle 2 has superior exergetic performance. [ABSTRACT FROM AUTHOR]

Recently, research and development on progressive and efficient hydrogen production methods has been paid lots of attention due to carbon-free feature of hydrogen. Application of nanoparticles to enhance an integrated solar-based hydrogen production unit is suggested and investigated in this work. The integrated plant consists of parabolic trough collectors coupled with a Kalina cycle for electricity generation to be consumed in a polymer electrolyte membrane electrolyzer for hydrogen production. The system performance is apprised for nanofluid as the heat transfer media for solar collectors and is compared with the pure basefluid case. Thermal model for parabolic trough collectors as well as thermodynamic models for Kalina cycle and electrolyzer are developed and validated. Also, thermo physical properties of nanofluid is assessed based on volume fraction of the nanoparticles. Parametric analyses are implemented for system performance assessment in which influence of design variables related to solar collectors, nanoparticels as well as the Kalina cycle are appraised. The effect on the hydrogen rate and solar-to-hydrogen exergy efficiency of design variables are comprehensively examined and discussed. According to the obtained results, the η e x , S T H is found to be 9.19% for the case with basefluid (without nanoparticles), whereas it can be improved to 9.63% with employment of 5% volume fraction of CuO nanoparticles. Such an efficiency improvement is due to the increment of hydrogen production from 0.669 kg/h to 0.702 kg/h using CuO-based nanofluid. • Effect of nanoparticles are evaluated in a PTC unit applied for hydrogen production. • Kalina cycle and PEM electrolyzer is used for electricity and hydrogen production. • Thermal and exergetic evaluations are carried out for performance investigation. • The CuO is found as the best nanoparticle among the three considered types. • Performance enhancement of around 5% is found with nanoparticle incorporation. [ABSTRACT FROM AUTHOR]

This work discusses the novel application of proton exchange membrane fuel cells (PEMFC) in the transport sector as well as portable applications. This kind of fuel cell produces a considerable quantity of heat while in operation. This quantity of heat is about 45–60% of entire energy composition of the hydrogen that is introduced into the cell. A correctly built cooling system must be used to efficiently eliminate produced heat from the stack to extend the stack's life and preserve its efficiency throughout its entire lifespan. Using appropriate thermal management techniques coupled with exploiting possibilities for fuel cell heat recovery may significantly improve size, cost, etc., while also reducing its total energy consumption. It is possible to collect and utilise the heat produced by PEMFC in other applications. A thorough analysis of heat recovery possibilities in this type of fuel cells is presented in this investigation. Similarly, the study further touched on the need for experimental studies into waste heat recovery from proton exchange membrane fuel cells as most of the recent work being championed are modelling based and does not really present a real life scenario of the system investigated. The need for investigations into the environmental performance of the waste heat recovery unit coupled to the proton exchange fuel cell system is also another important research direction that must be considered in future studies. Finally most of the studies on waste heat recovery from fuel cells have largely employed the use of organic Rankine cycle but other types of thermodynamic cycles like Kalina cycle is however recommended for further investigations due to their range of operation hence making them suitable for low and high temperature proton exchange membrane fuel cells. • Role of PEMFC in the transport sector as well as portable applications was discussed. • PEM Fuel cell in Combine Heat and Power Applications was illustrated. • Waste heat recovery in FCs was summarised. [ABSTRACT FROM AUTHOR]

Energy recovery and hydrogen production are essential in the current energy horizon of the globe. Applying the waste thermal energy and producing clean fuels in the power-generating cycles by keeping a sustainable view are the main goals of the current study. A combined Brayton-Kalina cycle accompanied by a PEM hydrogen production unit is studied using thermodynamic, exergetic, and economic evaluations. An external source is applied to supply the required heat for the closed Brayton cycle and the waste thermal energy is fed into the Kalina cycle. The Brayton cycle destructs more exergy than the Kalina cycle, respectively by the sharing value of 58% and 40%. The Brayton cycle shows the highest investment cost rate and the Kalina sets in the next rank. The PEM unit needs about 1% share of the total investment cost rate. A multi-objective optimization using NSGA-II algorithm is conducted to find the best operating conditions, considering the energy and exergy efficiency as well as investment cost rate function, as the objectives. The optimization makes an increase of 6% and 3% respectively in the total energy and exergy efficiency compared to the base working conditions, while it raises the investment cost rate by about 15%. • A combined Brayton-Kalina cycle with power and hydrogen output was considered. • By 30K rise in inlet condenser coolant temperature, the Kalina power decreased 50%. • A higher PEM's electrical current made a decrement in its exergy efficiency by 5%. • The Brayton cycle required the highest investment cost rate. • The optimization enhanced the total energy and exergy efficiency. [ABSTRACT FROM AUTHOR]

The current research is conducted with the aim of investigating a multi-generation energy system (MGS) for electricity, hydrogen, heating, cooling and hot water production using SRC, Kalina cycle and proton exchange membrane (PEM) electrolysis as the main subsystems. The thermodynamic analysis namely energy, exergy, and exergo-economic examination carried out. Analysis for each component is done after thermodynamic modeling. The exergy investigation showed that regenerator 2, vapor generator and condenser had the highest exergy destruction rate, respectively. A comparison was made between the current work and the basic system, and according to the results obtained, the system's ability to produce electricity, cooling, heating and hydrogen are calculated as 782 kW, 173.2 kW, 2265 kW and 0.01613 mol/day, respectively. Also, the energy and exergy efficiency of the proposed system increased by 3.13% and 5.37%, respectively. The optimization based on PSO method was carried out. The results of PSO optimization represented that in the case exergy destruction and exergy efficiency will be the optimization target these two outputs can reach the value of 2208 kW and 9.84%, while optimization based on exergy efficiency and production cost rate will lead to 9.86% and 166.6 $/h. • Simulation a CSP based system to design a poly-generation energy system. • Using PEM electrolyzer to generate hydrogen as an energy storage media. • The exergy efficiency of introduced system is 3.13% higher than basic system. • The output power of new plant is 1.54 MW higher than basic cycle. [ABSTRACT FROM AUTHOR]

In this research, two thermodynamic cycles based on gas turbine (GT) have been thermodynamically modeled and compared. The basic cycle is a Brayton cycle with thermoelectric and a supercritical carbon dioxide cycle. In the proposed system, a supercritical carbon dioxide cycle with photovoltaic thermal (PVT) unit and a Kalina cycle have been added to the existing system to recover more dissipated heat from GT unit. Thermodynamic modeling of the mentioned cycles has been done with Engineering Equation Solver software. For each component of the systems, mass, energy and exergy balance has been carried out. Also, appropriate relationships are defined for evaluating systems. The results of energy analysis of the systems show that the proposed plant produces net power 33585 kW and the fuel flow in the combustion chamber is 1.67 kg/s. Also, the employed electrolyzer produces 16.90 kg/day of hydrogen. Also, the analysis of the second law showed that although the proposed system produces 18320 kW power more than the base cycle, it has more exergy destruction rate by about 1912 kW. The proposed system has energy and exergy efficiency by about 1.34% and 1.93% more than the basic system. The results of the exegy analysis also make it clear that the combustion chamber and PVT unit have the lowest exergy efficiencies. The parametric analysis indicated that the compressor pressure ratio and gas turbine inlet temperature have important influence on the overall performance of the system, while the effects of the working pressure of both supercritical carbon dioxide cycles are insignificant. • Design a new integrated system with hydrogen as green energy carrier. • Integrated solar PVT and thermoelectric to enhance the performance. • Comprehensive parametric analysis was conducted. • PVT shows the lowest exergy efficiency among all compartments. [ABSTRACT FROM AUTHOR]

It is crucial to evaluate the impact of key parameters of multi-generation systems on their performance characteristics in order to develop efficient systems. The present study conducts parametric analysis of a PTSC-driven trigeneration system with a novel energy distribution based on direct-fed ORC and bottom-cycled arrangement of double-effect absorption refrigeration cycle and Kalina cycle system. Three different ORC structures (simple, regenerative, and ORC integrated with intermediate heat exchanger - IHE) are proposed. Effect of key ORC parameters namely ORC evaporator pinch point temperature and pump inlet temperature is examined on the thermodynamic performance of systems. Decrease of pinch point temperature enhances overall efficiencies and heating power in all three configurations, and increases (decreases) the net electrical power for ORC and regenerative ORC (RORC) based systems. This also enhances the cooling power of the RORC based system, though it has no impact on the cooling power of the ORC and ORC-IHE based systems. Reduction of the ORC pump inlet temperature increases overall exergy efficiency in all hybrid systems and overall energy efficiency in the ORC and ORC-IHE based systems, whereas it slightly decreases for the RORC based system. Based on a comparative study, performance of the proposed systems is found to be higher than related solar-driven multi-generation systems in the literature. [ABSTRACT FROM AUTHOR]

Geothermal energy is a promising solution to provide multiple outputs at different temperatures and under different conditions. In this current work, a geothermally powered multigeneration cycle is planned, suggested and studied including a Kalina cycle, an organic Rankine cycle, a thermoelectric generators, a double effect absorption refrigeration system, a dryer, a domestic water heater, a multi-effect desalination processes, a greenhouse, and hydrogen production and storage units. The main objective of this study is to generate power, cooling, heating, hot water, drying, greenhouse heating, hydrogen, oxygen, and freshwater in an environmentally harmless approach. An elaborated thermodynamic analysis of the developed research is calculated by energy and exergy efficiency methods. Furthermore, the parametric modeling is employed to calculate the effect of significant variables on the examined study and subsystems' efficiency. Looking the analysis's findings reveal that the evaluated model's net power generation rate is approximately 298 k W. Additionally, the cooling and heating rates of this integrated combined plant are 1169 k W and 1783 k W , respectively. Moreover, the examined plant produces 0.000392 k g / s of hydrogen and 2.77 k g / s of freshwater. Finally, the examined cycle energy and exergy performance is computed as 0.4248 and 0.3826, respectively. • A new design geothermal energy based combined plant is proposed. • Investigating the integration of the different subsystems. • To examine the fresh water and green hydrogen generation with geothermal energy. • To conduct comprehensive thermodynamic performance analysis. • The overall energy and exergy efficiencies are 0.4248 and 0.3826, respectively. [ABSTRACT FROM AUTHOR]

Biogas fuel has gained recognition as a highly suitable alternative to fossil fuels, attributed to its renewable nature and remarkable energy density. Biogas fuel utilization facilitates the integration of combined energy systems equipped with multi-generational structures, rendering them suitable for long-term planning and management. Hence, this study presents a unique approach to using biogas for multigeneration, exhibiting enhanced thermodynamic efficiencies and negative carbon dioxide emissions. To achieve the stated objective, an innovative system is devised that involves the utilization of a biogas separation unit in integration with several other components, including a LNG cold energy utilization unit, an ammonia Rankine cycle, a desalination unit, a Kalina cycle, a solid oxide electrolyzer cell, a biomethane combined cycle, and a methanol synthesis unit. The newly devised configuration is simulated through the Aspen HYSYS software and assessed from energy, exergy, environmental, and economic considerations. Based on the research findings, the suggested methodology exhibits energy and exergy efficiencies of 91% and 83%, correspondingly. Furthermore, the evaluation of the entire unit cost of the product and the levelized energy cost reveals values of 4.81 $/GJ and 0.033 $/kWh, respectively. The carbon dioxide emission intensity of the newly implemented process is calculated to be − 0.1041 kg/kWh. The economic aspects reveal a favorable net present value of 1470.6 M$ and a payback period of 5.29 years. [Display omitted] • Use of Aspen HYSYS for simulating a novel polygeneration process based on biogas. • Proposed structure uses biogas separation unit and LNG cold energy utilization unit. • Producing power, cooling, heat, fresh water, liquid CO 2 , biomethane, and methanol. • Exergy efficiency and total unit cost of product equal 83% and 81.4 $/GJ. • The net carbon dioxide emission intensity for the new process is − 0.1041 kg/kWh. [ABSTRACT FROM AUTHOR]

Natural gas power plants play a pivotal role in power generation; nevertheless, their waste heat contributes to diminished thermodynamic efficiencies and the release of carbon dioxide emissions. One primary approach involves implementing effective heat recovery strategies to generate various products. The present study suggests a novel approach to heat recovery in different stages utilizing series and parallel arrangements within an environmentally friendly design to enhance controllability while expanding the range of products. The present study includes a steam methane reforming process, a Kalina cycle, a multi-effect desalination unit, a methanol synthesis unit, two organic Rankine cycles, and two ammonia Rankine cycles. The primary objective of this system is to efficiently and concurrently produce electricity, hot water, chilled water, fresh water, and methanol. The findings reveal that the newly devised process exhibits energy and exergy efficiencies of 47.55% and 50.58%, respectively, while the total unit cost of products amounts to 7.69 $/GJ. From an environmental perspective, the results indicate that the proposed structure exhibits a total net emission of 87.1 × 103 kg/h and a CO 2 footprint of 0.22 kg CO2 /kWh. Ultimately, the economic assessment elucidates that the fixed investment cost, total investment cost, total annual cost, and net present value are equivalent to 373.0 M$, 496.1 M$, 207.5 M$, and 598.6 M$, respectively. • Proposal of a new polygeneration system coupled with steam methane reforming process. • Producing electricity, methanol, freshwater, heat, and coolant using cascade heat integration. • Numerical simulation using Aspen HYSYS software and a comprehensive 4E study. • Energy and exergy efficiencies and products' unit cost are 47.55%, 50.58%, and 7.69 $/GJ. • Total net emissions and CO 2 footprint are found at 87094.99 kg/hand 0.22 kg CO2 /kWh. [ABSTRACT FROM AUTHOR]

In order to boost the cycles' thermal efficiency, their power generations and reduce industrial equipment costs the growing need to develop and improve the performance of power generation cycles has provided the basis for research. Currently, there are quite a few investigations aiming to consider Kalina cycles as a power generation system using low-grade heat sources. In this research, firstly KCS-11 (Kalina Cycle System11) as well as Ekalina cycle (enhanced KCS-11 with ejector) has been studied. The SEKalina cycle, which is a modification of Ekalina cycle, is introduced, examined, and simulated by EES software. In the structure of the EKalina, the throttle valve and absorber are removed and the ejector is used instead. The use of the ejector reduces pressure at the turbine's outlet and augments the difference between the enthalpy of two turbine ends, leading to enhancement of the thermal proficiency and net power output. Including an ejector and benefited from a split configuration, SEKalina cycle proposes a potential for efficiency improvement. Examining the results of the cycles, it is found that by employing the SEKalina cycle, compare to the two previously introduced cycles (EKalina and KCS-11), the thermal efficiency and net power output rise significantly. Moreover, as a result, the net power output in SEKalina cycle is 2% higher than that of EKalina cycle. [ABSTRACT FROM AUTHOR]

This research presents a novel, eco-efficient hybrid system designed for the simultaneous production of power, oxygen, and methanol. It utilizes energy from coke plants and incorporates state-of-the-art waste heat recovery processes (WHRPs). The system effectively merges electricity and methanol production with WHRPs, improving both environmental sustainability and economic feasibility in industrial energy transformation. It consists of a fuel reforming and combustion unit, a waste heat recovery unit, a unit for hydrogen gas production through water electrolysis, and a methanol synthesis module. This configuration enables the production of 12.72 MW of electricity, 0.51 kg/s of oxygen, and 0.53 kg/s of methanol, achieving an energy productivity of 46.8 % and an exergy efficiency of 85.13 %. The economic analysis indicates competitive costs of $0.099 per kWh for electricity and $0.56 per kg for methanol. The system surpasses current technologies in thermodynamic efficiency, operational and product costs, and reduced CO2 emissions, demonstrating its potential as a sustainable and economically sound solution for industrial energy challenges. It supports global sustainability initiatives and fits within the circular economy concept.

This paper presents a novel multigeneration system that utilizes ammonia as the primary fuel for marine vessel applications. The system integrates and thermodynamically investigates various components, including solid oxide fuel cells (SOFC), gas turbines (GT), proton exchange membrane fuel cells (PEMFC), organic Rankine cycle (ORC), steam Rankine cycle (SRC), Kalina cycle (KC), and waste heat boiler (WHB). The primary objective of the integration strategy is to recover waste heat from the SOFC and harness the power generated by the PEMFC, resulting in improved thermal efficiency, reduced vessel startup time, and enhanced environmental sustainability. Mathematical models have been developed to facilitate the examination of the system’s thermodynamic performance. Comprehensive thermodynamic modeling employing energy and exergy analysis methods is employed to evaluate the effectiveness of both the proposed system and its subsystem. Moreover, the exergy destruction of all system components and integrated subsystems is quantified to provide a comprehensive understanding of their impact. The projected system exhibits an energy efficiency of 60.69% and an exergy efficiency of 57.50%. The waste heat recovery combined systems generate 1634.46 kW, accounting for 30.07% of the total power output of the integrated SOFC system. The performance of the system was analyzed through parametric studies, where different values of current density, distribution ratio (β) (from 0.1–0.4), and δ parameter (from 0–0.5) were examined. The findings revealed that increasing the current density led to a decrease in energy and exergy efficiency, despite an overall rise in the power output of the cogeneration system. Moreover, the waste heat boiler is capable of providing 1081 kg/h of superheated steam at 162 °C and 405 kPa to fulfill the heating requirements of marine lubricating oil, devices, and accommodation for seafarers on board the ship.

This article introduces a novel multiple-cycle generation system for efficient heat recovery at high and low temperatures. The system is modeled and optimized using the M2EP analysis method (mass, energy, exergy, and performance) and the particle swarm optimization algorithm. The multigeneration system produces electricity, cold, domestic hot water, and biogas by utilizing Kalina cycles, diffusion–absorption refrigeration machines, and high-performance heat exchangers by harnessing waste heat from cement kiln exhaust gases. The Kalina cycle is employed for electricity generation, wherein the H2O+NH3 mixture, heated by hot water, circulates through heat exchangers. Downstream of the Kalina cycle, the refrigeration machine generates cold by evaporating the strong solution of the H2O+NH3 mixture. Hydrogen circulates in the diffusion–absorption refrigerator (DAR) circuit, facilitating the exchange between the evaporator and the absorber. The domestic hot water and biogas production systems operate at lower temperatures (around 45 °C). The simulation results for the Kalina cycle indicate an electrical energy production of 2565.03 kW, with a release of usable energy (residual gases) estimated at 7368.20 kW and a thermal efficiency of 22.15%. Exergy destruction is highest at heat exchanger 1, accounting for 26% of the total. A coefficient of performance of 0.268 and an evaporator temperature of 10.57 °C were obtained for the DAR cycle. The absorber contributes the most to energy exchanges, comprising 37% of the entire circuit. Summarizing the potential for valorizing waste heat from cement kilns, this article lays the foundation for future research.

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.

This paper presents an innovative trigeneration system designed for efficient power, cooling, and hydrogen production. It combines a supercritical carbon dioxide (sCO2) power cycle with a Kalina cycle (KC) and an ammonia-water-based absorption refrigeration cycle (ARC), all integrated with a PEM electrolyzer (PEME) unit. The system optimally utilizes waste heat from the sCO2 power cycle to enhance power generation through the KC and provide cooling via the ARC. Additionally, it leverages the PEME system and KC-generated power for eco-friendly hydrogen production. Mathematical models, thermodynamic, and exergoeconomic analyses were performed, including parametric studies, optimization, and comparative analyses. The results indicate that the reactor experiences the highest exergy destruction rate, while components in the bottoming cycles exhibit lower exergy destruction. From an exergoeconomic perspective, the reactor and sCO2 turbine are ranked as the first and second most significant components. Under the optimal conditions, the system achieved a 9.76 % increase in exergy efficiency and a 6.63 % reduction in total product unit cost. The system also provides substantial net power output, cooling capacity, and hydrogen production rates of 261.74 MW, 123.95 MW, and 176.328 kg/h, respectively. These findings highlight the system's significant thermodynamic and economic advantages, making it a promising choice for diverse user needs.

• Integrating organic Rankine and Kalina cycles with compressed refrigeration cycle. • Examining the systems from thermodynamic, economic and environmental standpoints. • Reducing power consumption of compressed refrigeration cycle by 14.01 MWh/year. • Reducing CO 2 emissions by 3.96 ton/year. The compressed refrigeration cycle (CRC) is one of the popular cooling production cycles, which has important advantages. However, it has high power consumption and significant waste heat. Due to the arising costs of power consumption, the generated heat is very valuable. Moreover, this heat is good enough to be utilized as the heat source of the Organic Rankine cycle (ORC) and Kalina cycle (KC) which are capable of using low-temperature heat sources. In the present work, to improve this integration, the effects of configuration changes for integrating CRC with ORC equipped with a regenerator (system 1), ORC equipped with turbine bleeding (system 2), KC equipped with a regenerator (system 3), and KC equipped with a flash vessel and turbine (system 4) are presented. The proposed systems are examined and compared from energy, exergy, economics, environmental, and exergoenvironmental perspectives. If System 2 is used, the coefficient of performance is improved 2.05 %, i.e. 14.01 MWh/year and 3.96 ton/year reduction in the power consumption and the CO 2 emissions compared to CRC. On the other hand, exergy efficiency and exergoenvironmental impact factor are improved by 16.07 % and 2.46 %, respectively. Meanwhile, the payback period of system 2 is obtained as 2.6 years. To find the best system, a scoring method is performed and it is concluded that system 2 achieves a higher score even if the priorities change. [ABSTRACT FROM AUTHOR]

Various thermodynamic power cycles can be utilized to convert the low-to-medium temperature heat (available from many sources and has huge potential) to electricity and a detailed comparison between all of them is essential to identify the suitable one. Hence, to fulfill this research gap, six thermodynamic power cycles (Organic Rankine cycle with dry fluid, Organic Rankine cycle with wet fluid, Transcritical CO 2 Rankine cycle, Kalina cycle, Organic flash cycle and Trilateral flash cycle) have been compared for various heat source and sink temperatures. Objective functions are power generation, efficiency, irreversibility, cost, profit, environmental benefit, techno-economic parameters, etc. Study shows that the trilateral flash cycle is best for medium heat source temperature and the CO 2 cycle is best for low heat source temperature. The trilateral flash cycle shows an 11.5% higher exergy efficiency and 16.16% increment in annual profit at 160 °C heat source temperature as compared to the organic Rankine cycle with dry fluid. A decrease in condenser temperature is more advantageous than an increase. The study reveals that the CO 2 Rankine cycle would be advantageous for low-grade heat sources while the trilateral flash cycle for medium-grade heat sources in terms of performance, cost, design, operation and environmental benefits. [ABSTRACT FROM AUTHOR]

Gas turbine power cycles are among the most important power plants, operating in higher temperatures. Their principal defect is huge waste heat, leading to lower exergetic performances in addition to higher carbon dioxide (CO 2) emissions. In this regard, the current paper focuses on a new solution to solve these defects appropriately. For this purpose, a new thermal integration model is designed for a multigeneration purpose, which is able to decrease the CO 2 emission intensity below zero (a negative emission solution). The designed model comprises a steam power cycle, a Kalina power cycle, a dual organic Rankine cycle, a water desalination unit plus, and a methanol production unit plus. Thus, the products include electricity, heating, fresh water, and methanol. This system is simulated in the Aspen HYSYS software and is studied from the energy, exergy, economic, and environmental standpoints. According to the results obtained from the thermodynamic analysis, it is demonstrated that the total energy and exergy efficiencies are 49.38% and 66.5%, respectively. Furthermore, the net CO 2 emission intensity of the process is negative and equals − 1.036 kg CO2 /kg MeOH. Eventually, according to the economic evaluation, the methanol production cost equals 0.136 $/kg, which is 90.87% lower than the renewable methanol production method. [ABSTRACT FROM AUTHOR]

A novel power generation system suitable to recover waste heat from a renewable source at medium temperature level is investigated in the present work. In a regenerative system, saturated vapour is supplied to one of the heat exchangers by a secondary solar collector, which raises the temperature of the boiler as a whole. The main advantage of this method is the reduction in irreversibility in the mixing chamber M3, which encourages a higher flow rate to the turbine. Preheating the circulating solution and completely evaporating the basic stream are used to achieve this. The performance of the system is investigated in energy aspects along with detailed exergy analysis. Environmental impact as a result of the working conditions is essential to propose the optimum decision variables. Exergy analysis in both conventional and advanced methods proposes the system components which need improvements in themselves and associated with other components more properly. Exergoenvironmental analysis using the Life cycle assessment method is examined in the system under the hot sink conditions. Exergy analysis reveals that the component with a high source will yield more losses resulting in higher irreversibility. Hence, turbine and heat exchanger 4 (HE4) need investigation in improving the system's performance. Exergoenvironmental investigation suggests that the highest impact results same components identified by the advanced exergy analysis. Exergoenvironmental analysis on the proposed Kalina power generation system is carried out under hot sink conditions. The exergy destruction and destruction cost rate of 29.23 kW and 0.478 $ h-1 at turbine inlet conditions of 185 °C and 45 bar. The exergoenvironmental factor fb and the relative difference rb reveal that the components with high environmental impact have to be minimized. Turbine and HE4 are the components resulting in higher total exergy and devise related impact on the environment. [ABSTRACT FROM AUTHOR]

Three heat recovery cycles are studied to recover the waste heat from the exhaust gas outlet of a glass-melting furnace. To determine the viability and potential dangers based on techno-economic aspects, three fundamental recovery cycles for the exhaust gas from UK glass melting furnaces are examined. The parametric thermodynamic and techno-economic study reveals the effects of the key parameters: The condenser temperature of the ORC cycle, the pressure ratio of the s C O 2 cycle, and the flash pressure of the Kalina cycle. Three thermodynamic parameters (Power production, energy, and exergy efficiency), as well as five techno-economic parameters (LCOE, NPV, PP, IRR, and MOIC), have been studied with varying key factors. The results showed that ORC is the best possible option for low-temperature waste exhaust gases as it is not as expensive as other ones, while super-critical C O 2 has the highest power production to produce power from high-temperature waste heat sources. Even though ORC's payback period is 10% longer than s C O 2 's, Comparing the IRR, NPV, and MOIC of the ORC cycle to those of the s C O 2 cycle, the differences are just 8.3%, 5.3%, and 8.2% lower. [ABSTRACT FROM AUTHOR]

In recent years, there has been a growing emphasis on sustainable energy provision for sport facilities, aiming to reduce carbon emissions, promote energy efficiency, and create a more sustainable sporting environment. The present investigation concurs with introducing a novel trigeneration system intended to generate power and provide heating and cooling load for sports facilities. The present system is offered to sustain the general energy requirement of an intended sport compound independently throughout the year. The single-flash Geothermal (SFG) system is included as a measure for attaining the required energy to initialize the system. After producing power and providing heat load, the remaining exergy associated with the SFG system is harvested and utilized to drive the double-effect absorption chiller (DEAC), Kalina cycle (KC), and the Organic Rankine cycle (ORC). A further study based on the first law of thermodynamics revealed that the SFG system, KC, and ORC allot thermal efficiency by 5.724 %, 9.31 %, and10.26 %, respectively. Furthermore, the second-law investigation determined that the SFG system, KC, and ORC allocate exergetic efficiency by 18.08 %, 34.89 %, and 48.64 %, respectively. From an extended numerical perspective, the SFG system was deemed to result in a total output value of 66.55 kW worth of power and 615.8 kW worth of heating load. The DEAC performed with an 88.8 kW worth of cooling load provision and 1.199 as the coefficient of performance (COP). The KC and the ORC delivered 26.14 kW and 14.61 kW as in total outlet power, respectively. Integrally, the generalized system was found capable of producing 107.3 kW worth of net power output. The sum unit cost of the products (SUCP) was evaluated for the overall system, which equals 45.55$/GJ. A multi-objective Genetic algorithm optimization is carried out, aiming to achieve the optimal points and conditions of the system using the Pareto frontier method, where point C was chosen according to the TOPSIS criteria, deriving 46.0$/GJ and 40.09 % associated with SUCP and exergetic efficiency, respectively. Eventually, the exergoenvironmental parameters are derived and analyzed to study the environmental impacts. [ABSTRACT FROM AUTHOR]

Optimal thermo-economic integration of renewable energy sources with multi-generation energy systems is a prime research topic today. The present study proposes a multi-criteria evaluation method of such integration, based on combined heating and power (CHP), and combined cooling and power (CCP) scenarios, for three different solar intensities. Three novel solar-driven tri-generation systems are selected. They include different organic Rankine cycle (ORC) architectures and a Kalina cycle system (KCS) and a double-effect absorption refrigeration cycle as bottoming cycles. Evaluation of the tri-generation systems, both with and without the KCS system, indicates a performance improvement of up to 23% in various thermoeconomic characteristics when the KCS system is present. Selection of the suitable tri-generation system for each condition and optimization of the working fluid are carried out based on a multi-attribute decision-making method. P-xylene is found as the optimal organic working fluid for ORC and ORC (ORC integrated with internal heat exchanger) based systems, and benzene for the regenerative ORC-based system in both CHP and CCP scenarios. Multi-criteria analysis shows that ORC-based system outperforms other systems with net outranking flow of 0.44 (0.39) for CHP (CCP) application. The optimal configuration gives 95.6 M$ and 1.99 years for net present value and dynamic payback period, and 83.03% and 34.55% for energy and exergy efficiencies, respectively. [ABSTRACT FROM AUTHOR]

The energy and costs required to reliquefy the boil‐off gas (BOG) produced in liquefied natural gas (LNG) tanks are enormous. At the same time, LNG releases large amounts of cold energy during the regasification process. To recover both the BOG and the LNG cold energy for power generation, herein, a novel system consisting of a supercritical carbon dioxide recompression Brayton cycle, an ammonia–water mixture Kalina cycle, a BOG combustion turbine cycle, and a natural gas turbine cycle is presented. The genetic algorithm with multiple elite saving is used to optimize the system thermoeconomic performance, and the maximum energy efficiency, exergy efficiency, and net present value of 65.49%, 33.88%, and 7.374 × 107 $ are obtained respectively. The nondominated sorting genetic algorithm II is implemented to achieve the multiobjective optimization, and the comprehensive performance analysis is carried out on this basis. The results show that heat exchangers and turbines account for the highest exergy destruction and total cost proportion with the value of 76.5% and 81.1% respectively. The heat transfer curves between LNG and working fluids are well matched, and the cooling capacity for ammonia liquefaction is the largest, accounting for 66.66%, which also generates 581.2 kW of power generation. The results also indicate that the LNG cold energy cascade utilization system combined with BOG combustion has excellent thermodynamic performance and can obtain ideal economic benefits. [ABSTRACT FROM AUTHOR]

In this study, renewable energy sources including a high-temperature solar parabolic trough collector and geothermal water integrated with a modified Kalina cycle, a combined ORC-EJR cycle, an electrolyzer, an RO desalination unit, and a domestic water heater. SiO2 and TiO2 nanoparticles dissolved in Therminol VP1 are applied as the working fluid of the solar collector. A comparative analysis of introduced working fluids is performed from energy, exergy as well as cost analysis point of view to evaluate their efficiencies. Solar irradiation, ambient temperature, and collector inlet temperature were the parameters investigated to discover their effects on energy and exergy efficiency, solar collector outlet temperature, hydrogen production rate, and freshwater production rate. The highest generated outlet temperature of the solar collector outlet was 693.8 K obtained by Therminol VP1/SiO2 nanofluid. The maximum energy and exergy efficiencies of the proposed system were 36.69 % and 17.76 %, respectively. Moreover, it is found that by increasing the solar collector inlet temperature, the hydrogen production rate decreases while the water production rate increases.

In this proposed study, hydrogen and power generation by low-temperature geothermal energy supported Kalina cycle is thermodynamically investigated with an energy and exergy efficiencies approaches. This combined plant includes a Kalina cycle and a PEM electrolysis for power and hydrogen generation. The key purpose of this paper is to generate power and hydrogen in an environmentally benign way. Furthermore, environmental impact analysis is discussed to investigate the carbon dioxide emission that will be released if the power and amount of hydrogen obtained are produced with natural gas. As coming to the examination results, the energy and exergy performance of the overall plant 7.94% and 37.64%, respectively. Also, the net power and hydrogen production rates are computed as 100.5 kW and 0.0001191 kgs-1.

In this study, it is proposed to generate electrical energy by recovering the waste heat of an annealing furnace (AF) in an iron and steel plant using combined cycles such as steam Rankine cycle (SRC), organic Rankine cycle (ORC), Kalina cycle (KC) and transcritical CO2 cycle (t-CO2). Instead of releasing the waste heat into the atmosphere, the waste heat recovery system (WHRS) discharges the waste heat into the plant’s low-temperature oxygen line for the first time, achieving a lower temperature and pressure in the condenser than conventional systems. The waste heat of the flue gas (FG) with a temperature of 1093.15 K from the reheat furnace was evaluated using four different cycles. To maximize power generation, the SRC input temperature of the proposed system was studied parametrically. The cycles were analyzed based on thermal efficiency and net output power. The difference in SRC inlet temperature is 221.6 K for maximum power output. The proposed system currently has a thermal efficiency and total power output of 0.19 and 596.6 kW, respectively. As an environmental impact, an emission reduction potential of 23.16 tons/day was achieved. In addition, the minimum power generation cost of the proposed system is $0.1972 per kWh.

This study is motivated to propose, evaluate, and optimize a solar-based multigeneration system relying on consecutive heat integration. Here, a heliostat field is configured to collect solar power and supply high-temperature air toward a nitrogen-based Brayton cycle. Afterward, the output hot air is subjected to a Kalina cycle suitable for medium-temperature heat resumption. A double-effect absorption refrigeration cycle boosted by a Liquid-based natural gas cold energy recovery unit for power generation and natural gas regasification are the other subsystems. The principal purpose is to protect the energy level of the fluid evacuating the solar field and to minimize the irreversibility of the scheme since solar-based systems lead to major irreversibility. The designed process is apprised from a 3E perspective, including exergy, energy, and exergoeconomic analyses. In addition, a comprehensive sensitivity study is done based on the influence of effective factors on the exergy and energy efficiencies and unit cost of products. Eventually, a multi-objective optimization is performed to set the most suitable condition of decision parameters and reach the optimal unit cost of products and exergy performance (objective functions). To do optimization, a genetic algorithm is applied, and two decision-making approaches, i.e., LINMAP and TOPSIS, are regarded. The optimal objectives are gauged to be 24.76% and 15.90 $/GJ by TOPSIS and 24.47% and 15.73 $/GJ by LINMAP, respectively. [Display omitted] • Proposal of a novel poly-generation process using solar energy for urban usage. • Use of nitrogen-based Brayton cycle and Kalina cascade integrated with a heliostat field. • Energy, exergy, and economic analyses and coherent sensitivity study. • Use of a genetic algorithm + TOPSIS + LINMAP for multigeneration. • The optimum exergy efficiency and sum unit cost of products are 24.47% and 15.73 $/GJ. [ABSTRACT FROM AUTHOR]

The present investigation analyzes in deep a multi-generation system producing power, heating, and domestic consumable water. The system is based on renewable energy sources with approaches utilizing subterranean geothermal reservoir, allocating a considerable potential for means of generation. The system is comprised of a single-flash geothermal system, a dual-turbine Kalina cycle, an Organic Rankine Cycle with an internal heat exchanger and an open feed open heater, a supercritical CO 2 , and a reverse osmosis cycle. The analyzes carried out include energy, exergy, entransy, and exergoeconomic evaluation. Considering the base mode, the values are derived as 46.08%, 56.04%, 333.1MWK, and 16.89$/GJ for energy efficiency, exergy efficiency, entransy loss, and the sum unit cost of products. The coupling of the cycles demonstrated a novel configuration aimed at generating power, heating, and freshwater as a multi-generation system with substantial output potential. The outputs are total power output, heating load, and freshwater as 130.068 MW, 30.79 MW, and 44.97 kg/s, respectively. The remainder of the study includes four multi-objective optimization scenarios aimed at identifying the optimum conditions associated with energy efficiency, exergy efficiency, entransy loss, and the sum unit cost of products. The present investigation uses the Engineering Equation Solver to simulate the conditions of the concept. [ABSTRACT FROM AUTHOR]

• The condensation of NH 3 /H 2 O with mass concentrations of 80%−96% is measured. • High concentration NH 3 /H 2 O shows the same flow pattern characteristics as pure NH 3. • The heat transfer coefficients decrease with lower mass concentrations. • The sensitivity of frictional pressure drop indicates separated flow. • The investigated parameters are mass concentration, vapor quality, mass flux, etc. High concentration NH 3 /H 2 O is suitable for Kalina cycles used for the recovery of low grade heat. Plate heat exchangers (PHEs) are compact and reduce the charge of working fluid. This paper investigates the condensation of NH 3 /H 2 O with NH 3 mass concentrations of 80%-96%. The vapor and liquid concentrations are close to equilibrium state, which are different from normal absorbers. The apparent heat transfer coefficients (HTCs) and frictional pressure drop are presented, covering the mass fluxes of 32–86 kgm−2s−1, the averaged vapor qualities of 0.08–0.65 and the saturated pressure of 610 to 780 kPa. Larger mass fluxes noticeably increase the apparent HTCs and frictional pressure drop. At the mass concentrations of 96%, 91% and 88%, higher vapor qualities increase the apparent HTCs for large mass fluxes. The apparent HTCs decrease slightly with vapor qualities for 80% mass concentration. The experimental results are compared with those of pure NH 3. The flow patterns of high concentration NH 3 /H 2 O are considered as full film flow and partial film flow, which are the same as for NH 3. The mass transfer resistance deteriorates the heat transfer especially for partial film flow, which happens at small liquid mass fluxes. The mass transfer resistance has negligible influences on frictional pressure drop. [ABSTRACT FROM AUTHOR]

In this paper, a novel poly-generation system with high thermodynamic performance and low carbon dioxide (CO 2) emission is presented and analyzed from the 4E (energy, exergy, economic, and environmental) perspective. The newly designed structure consists a gas turbine cycle, transcritical CO 2 cycles, a Kalina power cycle, a water desalination unit, a methanol production unit, and a chiller. Toward this goal, the flue gas leaving the gas turbine cycle is processed and utilized. Thermodynamic analysis demonstrates that the total energy and exergy efficiencies are attainable at 58.75% and 69.46%, respectively. In addition, the total exergy destruction rate equals 183105 kW in which the gas turbine cycle is the major source of irreversibility with a share of 51%. In addition, exergy analysis indicates that the combustor of the gas turbine cycle has the highest exergy destruction ratio (44.54%) among all equipment. Regarding the environmental aspect, the total CO 2 emission and its emission intensity for the proposed process are 18678.42 kg CO2 /h and 0.75 kg CO2 /kg MeOH , respectively. Its indirect emission is responsible for 48.8% of the total emission as well. Attributable to the thermo-environmental results, the proposed process has a suitable performance compared to similar technologies. The economic analysis demonstrated that its total annual cost equals 60800563 $ and production costs of methanol, freshwater, heating, cooling, and power are 0.3 $/kg MeOH , 0.43 $/kg freshwater , 0.16 $/kg LPS , 0.022 $/kg chilled water , and 0.069 $/kWh, respectively. • A noel waste management for a gas turbine cycle aimed at multiple productions. • Use of combined power plants, desalination, chiller, and methanol production unit. • Use of Aspen Hysys for simulation and performing a comprehensive 4E analysis. • Energy and exergy efficiencies are attainable at 58.75% and 69.46%. • Total CO 2 emission intensity and methanol cost are 0.75 kg CO 2 kg MeOH and 0.3 $ / kg MeOH . [ABSTRACT FROM AUTHOR]