THERMODYNAMIC ANALYSIS OF SUGAR PRODUCTION SYSTEMS

In this work, we have considered a non-canonical scalar field dark energy model in the framework of flat FRW background. It has also been assumed that the dark matter sector interacts with the non-canonical dark energy sector through some interaction term. Using the solutions for this interacting non-canonical scalar field dark energy model, we have investigated the validity of generalized second law (GSL) of thermodynamics in various scenarios using first law and area law of thermodynamics. For this purpose, we have assumed two types of horizons viz apparent horizon and event horizon for the universe and using first law of thermodynamics, we have examined the validity of GSL on both apparent and event horizons. Next, we have considered two types of entropy-corrections on apparent and event horizons. Using the modified area law, we have examined the validity of GSL of thermodynamics on apparent and event horizons under some restrictions of model parameters.

The science of thermodynamics is built primarily on two fundamentally natural laws, known as the first and second laws. The first law of thermodynamics is simply an expression of the conservation of energy principle. It asserts that energy is a thermodynamic property, and that during an interaction, energy can change from one form to another but the total amount of energy remains constant. The second law of thermodynamics asserts that energy has quality as well as quantity, and actual processes occur in the direction of decreasing quality of energy. The attempts to quantify the quality or “work potential” of energy in light of the second law of thermodynamics has resulted in the definition of the property named exergy. In this chapter, basic relations for the first and second laws of thermodynamics are provided for closed systems and control volumes. The concepts of entropy and exergy derived from the second law are thoroughly discussed.KeywordsEntropy ChangeEntropy GenerationHeat EngineExergy AnalysisExergy EfficiencyThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

There are two primary laws including the first and second laws of thermodynamics that should be used to assess a process. Generally, only the first law of thermodynamics is investigated in numerical solutions, so it is possible to exist some numerical results that do not satisfy the second law of thermodynamics because of numerical errors. To achieve reliable numerical outcomes, it is better to apply two indexes of HEAT BALANCE ERROR and VIRTUAL ENTROPY GENERATION, which come from the second law of thermodynamics. In other words, an approach to develop computational fluid dynamics investigations is to take second law of thermodynamics into consideration. In this study, two different models including counterflow double‐pipe heat exchanger and single‐pipe with constant wall temperature are simulated in various cases with different efficiencies and temperature ratios. It is found that 46 cases of total 523 double‐pipe models and 24 cases of total 402 simulations of single‐pipe models had unacceptable results regarding to two mentioned criteria. The results revealed that it is less likely to gain unreliable results in smaller efficiency and lower inlet temperature for double‐pipe heat exchanger and single‐pipe respectively.

Bioenergy, sustainability, and the second law

A scale-invariant model of statistical mechanics and modified forms of the first and the second laws of thermodynamics

Second law analysis of multieffect and multistage flash desalination plants

The performance of turbochargers is heavily influenced by heat transfer. Conventional investigations are commonly performed under adiabatic assumptions and are based on the first law of thermodynamics, which is insufficient for perceiving the aerothermodynamic performance of turbochargers. This study aims to experimentally investigate the non-adiabatic performance of an automotive turbocharger turbine through energy and exergy analysis, considering heat transfer impacts. It is achieved based on experimental measurements and by implementing a novel innovative power-based approach to extract the amount of heat transfer. The turbocharger is measured on a hot gas test bench in both diabatic and adiabatic conditions. Consequently, by carrying out energy and exergy balances, the amount of lost available work due to heat transfer and internal irreversibilities within the turbine is quantified. The study allows researchers to achieve a deep understanding of the impacts of heat transfer on the aerothermodynamic performance of turbochargers, considering both the first and second laws of thermodynamics.

The result of this study shows the performance of Ihovbor Gas Power Plant in Benin, Edo State Nigeria using first and second law of thermodynamics. Analysing the efficiency of the plant using first law of thermodynamics showed that with increase in inlet air temperature, the energy conversion efficiency of the plant reduces. The exergy efficiency of the plant also confirmed that increase in inlet air temperature results in decrease of the exergetic efficiency of the plant. Analysis of each of the components showed the greatest destruction of exergy was in the combustion chamber while the least is the Gas turbine section. Using numerical method in analyzing the gas turbine plant when retrofitting with an evaporative inlet air cooler showed better performance in energy conversion as power generation increased with an average of 1% per 1oC degree fall in temperature, the work ratio and thermal efficiency of the plant also increased. The analysis of the modified plant using second law of thermodynamics showed an increase in magnitude of both the exergy destroyed and the efficiency of the plant. Analysis showed that integrating evaporative cooler as component of the inlet air cooler increases the efficiency of the Air compressor by over 0.8% thus increasing the plant’s exergetic efficiency.

This paper presents energy and exergy analyses of solar drying of coconuts in a hemispherical solar tunnel drier. Coconuts were dried from an initial moisture content of about 55% (w.b.) to 7% (w.b.) in the solar tunnel drier in 60 hrs whereas the open sun drying process takes 153 hrs for reducing the moisture content to the same level. The drying experiments were conducted at a mass flow rate of 7.25 kg/s with an average air velocity of 0.1 m/s. Using the first law of thermodynamics, energy analysis was carried out to estimate the amount of energy received by the solar tunnel drier and the ratios of energy utilization. However, exergy analysis was accomplished to determine the exergy loss and exergy efficiency by applying the second law of thermodynamics. Energy utilization, energy utilization ratio, exergy inflow and exergy loss in the drier were studied and these values are found to be increased with increasing solar radiation. The exergy inflow and exergy loss in the drier varied between 0.194 kJ/s–8.18 kJ/s and 0.085 kJ/s–5.377 kJ/s respectively. The exergy efficiency of the drier varied between 23.6%–53%.

This chapter examines scientific ideas that led to the theory of deep time, with particular emphasis on the work of William Thomson, later Lord Kelvin. Kelvin used the laws of physics to reject Charles Lyell's theory of uniformitarianism to explain an eternal, unchanging Earth. The first law of thermodynamics holds that in any process, energy in the form of heat and work is conserved. The second law can be stated simply as: heat flows spontaneously from hotter to colder places, never the opposite. In describing geologic time as infinite and the Earth as unchanging, Lyell claimed that the Earth is a perpetual-motion machine, one that can not only win the energy battle but go on doing so forever. But the first and second laws of thermodynamics prove that such a machine is impossible. According to Kelvin, Lyell's theory “violates the principles of natural philosophy.” This chapter considers Kelvin's argument about the age of the Earth and how he pushed geology toward the twentieth century.

<div class="htmlview paragraph">The design of any complex system, especially eco-technical is very challenging due to the variety of processes, system composition, relation between different components and presence of the human. Process and technology selections affect the flow rate, composition, and phase of all resulting components. Therefore, evaluating alternative processes and/or technologies used often requires one to compare the relative environmental merits of distinctly different residual streams.</div> <div class="htmlview paragraph">Traditional thermodynamic analysis based on the first law of thermodynamics describes the conservation of energy. In this type of analysis all forms of energy are considered to be equivalent. The loss of quality of energy is not taken into account. It shows the energy flow to be continuous and energy balance is always closed. There can never be an energy loss, only energy transfer to the environment in which case it is useless.</div> <div class="htmlview paragraph">An exergy analysis, based on the first and second law of thermodynamics, shows the thermodynamic imperfection of a process and the system, including all quality losses of materials and energy. For quantifying the irreversibilities and determining system imperfections an exergy analysis has to be performed.</div> <div class="htmlview paragraph">The intent of this paper is to provide a better explanation of exergy method and show examples of it's application.</div>

Coal to SNG: Technical progress, modeling and system optimization through exergy analysis

Exergy is an effective metric to evaluate the performance of energy systems. Exergy analysis has been extensively used to study and understand loss mechanisms of Internal Combustion Engines (ICEs). However knowledge from exergy analysis has not been used for control of ICEs. This paper presents the first application of exergy-based control to ICEs. In this paper, an exergy model is developed for an advanced ICE with low temperature combustion mode that has higher efficiency compared to conventional diesel and spark ignition engines. The exergy model is based on quantification of the Second Law of Thermodynamic (SLT) and irreversibilities which are not identified in commonly used First Law of Thermodynamics (FLT) analysis. An optimal control method is developed based on minimizing irreversibilities and exergy losses. The new controller finds the optimum combustion phasing at every given engine load to minimize exergy destruction/loss. Application of the new developed control algorithm is demonstrated for a Combined Heat and Power (CHP) case study. The results show that by using the exergy-based optimal control strategy, the engine output power and exhaust exergies are maximized.

Experimental study on heat and exergy balance of a dual-fuel combined injection engine with hydrogen and gasoline

Based solely on the First Law of Thermodynamics, which addresses energy efficiency, heat pumps are considered to be a major asset for achieving the decarbonization goals of the Paris Agreement. Yet, this approach alone overestimates the potential for decarbonization and conceals certain root causes of carbon dioxide emissions arising from exergy destruction. This paper redefines the decarbonization potential of heat pumps holistically by applying the First and Second Laws of thermodynamics together. This research shows that power-to-heat energy conversion systems are responsible for exergy destruction, leading to additional carbon dioxide emissions, as the destroyed exergy must be offset by other means, possibly by burning fossil fuels. An exergy-based model was developed and used for different scenarios. Results were compared with boilers in heating mode fueled by fossil fuels or biogas, and with adsorption machines in cooling mode. Thermal energy storage systems and their optimal operational regimes for minimum environmental footprint have also been considered and modeled in accordance with the Second Law of Thermodynamics. A correction factor for the coefficient of performance of heat pumps has been developed to account for exergy destruction and emission avoidance associated with typical heat pump operation under electrical and ambient thermal inputs. Results show that today’s coefficient of performance must be higher to meet the emissions-mitigation and total electrification targets to mitigate global warming. The Second Law of thermodynamics shows that the case study about the comfort cooling system of a nature center building with ground source heat pumps and photovoltaic panels is responsible for emissions by 0.81 kg CO2 emissions/kWen-h, rather than saving 1.62 kg CO2/kWen-h by a no-heat pump case, comprising solar photovoltaic panels, adsorption cooling, and desiccant wheel. This case study also shows that the carbon dioxide emission responsibility resulting from exergy destruction during the power-to-heat process is as important as the direct emissions from electric power use. This paper concludes that the exergy destruction-related carbon footprint should not be neglected across all design and application phases to foster better awareness and establish exergy-rational strategy planning towards the Paris Agreement goals.