Luciana FONSECA, Carlos Eduardo Lima OLİVEİRA, Marco Aurélio CREMASCO
Terpene compounds in the lower layer of the atmosphere can contribute to environmental problems through the formation of particulate material known as secondary organic aerosol (SOA). A clear understanding of the formation and composition of these particles hinges on reliable thermodynamic data. Quick estimation of these physical properties is highly desired. While experimental methods require significant resources and time, the prediction of pure-component properties through group contributions is easily applicable and straightforward. The present study compares the experimental enthalpies of vaporization at 298.15 K for bicyclic terpenes and related substances derived from the gas chromatography technique with estimated values provided by three group contribution methods. A new group contribution model specifically designed for terpene compounds is introduced. Furthermore, this study reveals previously unreported values in the literature for the enthalpy of vaporization at 298.15 K and the normal boiling temperature of Thymol methyl ether, Fenchyl alcohol, and Bicyclo [4.1.0] heptane-7-carboxylic acid.
{"title":"Thermodynamic Properties of Selected Bicyclic Terpenes and Related Substances by Gas Chromatography and Group Contributions","authors":"Luciana FONSECA, Carlos Eduardo Lima OLİVEİRA, Marco Aurélio CREMASCO","doi":"10.5541/ijot.1243089","DOIUrl":"https://doi.org/10.5541/ijot.1243089","url":null,"abstract":"Terpene compounds in the lower layer of the atmosphere can contribute to environmental problems through the formation of particulate material known as secondary organic aerosol (SOA). A clear understanding of the formation and composition of these particles hinges on reliable thermodynamic data. Quick estimation of these physical properties is highly desired. While experimental methods require significant resources and time, the prediction of pure-component properties through group contributions is easily applicable and straightforward. The present study compares the experimental enthalpies of vaporization at 298.15 K for bicyclic terpenes and related substances derived from the gas chromatography technique with estimated values provided by three group contribution methods. A new group contribution model specifically designed for terpene compounds is introduced. Furthermore, this study reveals previously unreported values in the literature for the enthalpy of vaporization at 298.15 K and the normal boiling temperature of Thymol methyl ether, Fenchyl alcohol, and Bicyclo [4.1.0] heptane-7-carboxylic acid.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135307992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High pressure is becoming an interesting area of research for originating vital properties in crystalline solids. In the present study, the pressure equation of the state of TiN was investigated by employing various equations of state (EoS) presented in the literature, such as Dodson EoS, Barden EOS, Birch-Murnaghan (B-M) EoS. The EoSs were processed to find the high-pressure effects on the characterizations of TiN such as volume compression ratio, bulk modulus B, Grüneisen parameter, and phonon frequency spectrum. It was shown that a gigantic pressure results in a significant reduction in the volume of the TiN material, and the volume compression ratio reduction, is almost the same for the existing equations of state and the comparative literature results up to a pressure of 80 GPa. The maximum pressure difference is observed to be 4.85 GPa. over the entire pressure of 120GPa. Increasing the bulk modulus with high pressure was expected by the present EoSs, and up to the pressure of about 60 GPa, all curves of bulk modulus are matched with each other. Eventually, a fair comparison has been made between the present results and the first principle approximation along with the generalized gradient approximation method in which a perfect agreement was observed. Finally, the feasibility of TiN EoS as a standard pressure calibration was demonstrated.
{"title":"High-Pressure Calibration TiN Equation of State","authors":"Sırwan KAREEM, Mohammad UONİS, Raed ALSAQA","doi":"10.5541/ijot.1168781","DOIUrl":"https://doi.org/10.5541/ijot.1168781","url":null,"abstract":"High pressure is becoming an interesting area of research for originating vital properties in crystalline solids. In the present study, the pressure equation of the state of TiN was investigated by employing various equations of state (EoS) presented in the literature, such as Dodson EoS, Barden EOS, Birch-Murnaghan (B-M) EoS. The EoSs were processed to find the high-pressure effects on the characterizations of TiN such as volume compression ratio, bulk modulus B, Grüneisen parameter, and phonon frequency spectrum. It was shown that a gigantic pressure results in a significant reduction in the volume of the TiN material, and the volume compression ratio reduction, is almost the same for the existing equations of state and the comparative literature results up to a pressure of 80 GPa. The maximum pressure difference is observed to be 4.85 GPa. over the entire pressure of 120GPa. Increasing the bulk modulus with high pressure was expected by the present EoSs, and up to the pressure of about 60 GPa, all curves of bulk modulus are matched with each other. Eventually, a fair comparison has been made between the present results and the first principle approximation along with the generalized gradient approximation method in which a perfect agreement was observed. Finally, the feasibility of TiN EoS as a standard pressure calibration was demonstrated.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135786426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Derivatives of quinoline are widely utilized in both industries and in healthcare. To understand the quinolines' quality and stability in usage, it is crucial to study their phase transition chemical thermodynamic characteristics. In this work, the phase transition thermodynamic characters of 2-methylquinoline (quinaldine), 2-chloroquinoline, and 2-phenylquinoline were investigated. Moreover, the sublimation/vaporization enthalpy of the compounds were determined the solution calorimetry-additivity scheme approach at 298.15 K. The solution calorimetry was applied to measure solution enthalpies of the compounds in benzene solvent at 298.15 K. While, the solvation enthalpy of the compounds were calculated additivity scheme approach. In addition, the transpiration method applied to estimate vapor pressure to temperature dependency to 2-Chloroquinoline. In consequence, the vapor pressure values with respect to temperature variation was determined to 2-Chloroquinoline compound for the first time. As a result, the phase transition chemical thermodynamic properties; enthalpy, entropy, and Gibbs energy for 2-methylquinoline, 2-chloroquinoline and 2-phenylquinoline were determined from crystalline/liquid to gas phase. Furthermore, in this work the thermochemical characteristics values of the studied compounds exhibited higher accuracy to those in literature data. Finally, the phase transition thermodynamically studied on 2-position of the quinoline compound, where it substituted to methyl, chloro and phenyl groups.
{"title":"Phase Transition Thermodynamic Properties Of 2-Methylquinoline, 2-Chloroquinoline And 2-Phenylquinoline","authors":"Rawand ABDULLAH, Boris SOLOMONOV","doi":"10.5541/ijot.1250292","DOIUrl":"https://doi.org/10.5541/ijot.1250292","url":null,"abstract":"Derivatives of quinoline are widely utilized in both industries and in healthcare. To understand the quinolines' quality and stability in usage, it is crucial to study their phase transition chemical thermodynamic characteristics. In this work, the phase transition thermodynamic characters of 2-methylquinoline (quinaldine), 2-chloroquinoline, and 2-phenylquinoline were investigated. Moreover, the sublimation/vaporization enthalpy of the compounds were determined the solution calorimetry-additivity scheme approach at 298.15 K. The solution calorimetry was applied to measure solution enthalpies of the compounds in benzene solvent at 298.15 K. While, the solvation enthalpy of the compounds were calculated additivity scheme approach. In addition, the transpiration method applied to estimate vapor pressure to temperature dependency to 2-Chloroquinoline. In consequence, the vapor pressure values with respect to temperature variation was determined to 2-Chloroquinoline compound for the first time. As a result, the phase transition chemical thermodynamic properties; enthalpy, entropy, and Gibbs energy for 2-methylquinoline, 2-chloroquinoline and 2-phenylquinoline were determined from crystalline/liquid to gas phase. Furthermore, in this work the thermochemical characteristics values of the studied compounds exhibited higher accuracy to those in literature data. Finally, the phase transition thermodynamically studied on 2-position of the quinoline compound, where it substituted to methyl, chloro and phenyl groups.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135981094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Experimental analysis was conducted to investigate the turbulent heat transfer behaviors within a tubular heat exchanger, incorporating a novel baffle plate design. The new design includes a perforated circular baffle plate with a rectangular flow deflector that can be adjusted to different inclination angles. The baffle plate is strategically positioned at the entrance of the heat exchanger, resulting in a swirling flow downstream. To assess the impact of the baffle plate design, three baffle plates were placed longitudinally along the flow, with varying pitch ratios (l/D). The effects of pitch ratio (ranging from 0.6 to 1.2), deflector inclination angle (ranging between 30⁰ to 50⁰), and Reynolds numbers (ranging between 16000 to 29000) were examined. The outcomes highlighted the substantial impact of pitch ratio and inclination angle on the thermal enhancement factor. In particular, compared to single segmental baffle plates working under similar operating conditions. The result indicates that an inclination angle of 30° and a pitch ratio of 1 exhibited an average 41.49% augmentation in thermal-fluidic performance compared with an exchanger with a segmental baffle plate.
{"title":"Experimental Investigations on Single-Phase Heat Transfer Enhancement in an Air-To-Water Heat Exchanger with Rectangular Perforated Flow Deflector Baffle Plate","authors":"Atıqur RAHMAN","doi":"10.5541/ijot.1285385","DOIUrl":"https://doi.org/10.5541/ijot.1285385","url":null,"abstract":"Experimental analysis was conducted to investigate the turbulent heat transfer behaviors within a tubular heat exchanger, incorporating a novel baffle plate design. The new design includes a perforated circular baffle plate with a rectangular flow deflector that can be adjusted to different inclination angles. The baffle plate is strategically positioned at the entrance of the heat exchanger, resulting in a swirling flow downstream. To assess the impact of the baffle plate design, three baffle plates were placed longitudinally along the flow, with varying pitch ratios (l/D). The effects of pitch ratio (ranging from 0.6 to 1.2), deflector inclination angle (ranging between 30⁰ to 50⁰), and Reynolds numbers (ranging between 16000 to 29000) were examined. The outcomes highlighted the substantial impact of pitch ratio and inclination angle on the thermal enhancement factor. In particular, compared to single segmental baffle plates working under similar operating conditions. The result indicates that an inclination angle of 30° and a pitch ratio of 1 exhibited an average 41.49% augmentation in thermal-fluidic performance compared with an exchanger with a segmental baffle plate.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135936484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R-1243zf is a new refrigerant that could replace R-134a. Its thermodynamic properties represented in the equation of state (EOS) play an essential role in analyzing and designing thermal systems. The EOS exists without including caloric property data due to unavailable data during the development time. New EOS was developed explicitly in Helmholtz free energy and optimized to represent the experimental data accurately and maintain thermodynamic consistency. The optimization process undergoes using a genetic algorithm and weighted-least squares regression. The experimental data used in the optimization have a range of 233–430 K and 0.106–34.6 MPa and were validated from the extrapolation and consistency to confirm the reliability. The average absolute deviation from the data is 0.48% for the ideal gas isobaric specific heat, 1.7% for the isochoric specific heat, 0.33% for the speed of sound, 0.22% for the liquid density in single-phase, 0.49% for the vapor density in single-phase, 0.96% for the vapor pressure, 2.2% for the saturated liquid density, and 3.2% for the saturated vapor density. The EOS has a reasonable extrapolation behavior from the triple point up to 700 K and 100 MPa.
{"title":"New Thermodynamic Equation of State for Refrigerant HFO-1243zf","authors":"I Made ASTİNA, Hilmy Ilham ALFİSAHRİ","doi":"10.5541/ijot.1248571","DOIUrl":"https://doi.org/10.5541/ijot.1248571","url":null,"abstract":"R-1243zf is a new refrigerant that could replace R-134a. Its thermodynamic properties represented in the equation of state (EOS) play an essential role in analyzing and designing thermal systems. The EOS exists without including caloric property data due to unavailable data during the development time. New EOS was developed explicitly in Helmholtz free energy and optimized to represent the experimental data accurately and maintain thermodynamic consistency. The optimization process undergoes using a genetic algorithm and weighted-least squares regression. The experimental data used in the optimization have a range of 233–430 K and 0.106–34.6 MPa and were validated from the extrapolation and consistency to confirm the reliability. The average absolute deviation from the data is 0.48% for the ideal gas isobaric specific heat, 1.7% for the isochoric specific heat, 0.33% for the speed of sound, 0.22% for the liquid density in single-phase, 0.49% for the vapor density in single-phase, 0.96% for the vapor pressure, 2.2% for the saturated liquid density, and 3.2% for the saturated vapor density. The EOS has a reasonable extrapolation behavior from the triple point up to 700 K and 100 MPa.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135981202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the southern part of Libya, there are a number of power plants and other large industrial developments using their power systems, such as petroleum fields. Gas turbines are frequently employed due to water scarcity in the region, such as the Asrir field power plant. However, fuel transportation is one of the main difficulties regarding cost and safety. The annual cost of fuel operation and transportation is admitted to be very high; therefore, this work aims to utilize solar energy potential to reduce fuel consumption. In this context, a power plant that is currently in operation in Libya, which is located close to the Sahara Desert in the southwestern region, was selected as a case study. The region was chosen because it offers extraordinary conditions for the establishment of concentrated power plants. Simulations studies were carried out at full load considering the nature of the solar flux that varies with the meteorological conditions and the thermodynamic calculations were made based on algebraic equations describing the power cycle and the solar field. In addition, the feasibility of fulfilling the power cycle's energy required using the CSPs system was also analyzed. The annual behavior of the solar field was determined using hourly data within the system advisor model (SAM) software. In order to examine the possibility of fuel reduction, the cost of fuel was linked with an exergy analysis from an economic perspective. The findings revelated that the plant efficiency could be increased and the fuel mass rate ratio could be reduced by preheating the air temperature entering the combustion chamber. The air/fuel ratio at the combustor was found 43, the design heat energy required to deliver to the combustion chamber is 414.4MW, and the energetic thermal efficiency of the power cycle is 32.6%. The thermal power design of the solar field is 532MW when average direct irradiation is equal to 1000kWh/m².
{"title":"The Potential of Using the Incorporation of Concentrated Solar Power and Gas Turbines in the South of Libya","authors":"Sami Ehti̇wesh, Asya Gabbasa, Ismael Ehti̇wesh","doi":"10.5541/ijot.1293271","DOIUrl":"https://doi.org/10.5541/ijot.1293271","url":null,"abstract":"In the southern part of Libya, there are a number of power plants and other large industrial developments using their power systems, such as petroleum fields. Gas turbines are frequently employed due to water scarcity in the region, such as the Asrir field power plant. However, fuel transportation is one of the main difficulties regarding cost and safety. The annual cost of fuel operation and transportation is admitted to be very high; therefore, this work aims to utilize solar energy potential to reduce fuel consumption. In this context, a power plant that is currently in operation in Libya, which is located close to the Sahara Desert in the southwestern region, was selected as a case study. The region was chosen because it offers extraordinary conditions for the establishment of concentrated power plants. Simulations studies were carried out at full load considering the nature of the solar flux that varies with the meteorological conditions and the thermodynamic calculations were made based on algebraic equations describing the power cycle and the solar field. In addition, the feasibility of fulfilling the power cycle's energy required using the CSPs system was also analyzed. The annual behavior of the solar field was determined using hourly data within the system advisor model (SAM) software. In order to examine the possibility of fuel reduction, the cost of fuel was linked with an exergy analysis from an economic perspective. The findings revelated that the plant efficiency could be increased and the fuel mass rate ratio could be reduced by preheating the air temperature entering the combustion chamber. The air/fuel ratio at the combustor was found 43, the design heat energy required to deliver to the combustion chamber is 414.4MW, and the energetic thermal efficiency of the power cycle is 32.6%. The thermal power design of the solar field is 532MW when average direct irradiation is equal to 1000kWh/m².","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48695496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, new cycle is developed to generate simultaneously electrical and cooling power by placing a turbine between the generator and ejector in the conventional ejector-assisted absorption cooling cycle. The aim of developed cycle is to increase the exergy efficiency of cycle by adding an electrical power generation made it more environmentally friendly and reduce its dependents of fossil energy sources. The first, second laws of thermodynamic, mass and energy balance is applied for each cycle component and the constant mixing pressure ejector model is used to develop a numerical model of proposed cycle. The results depict that the augmentation of generation temperature is positively affected the work produced in the turbine contrary for cycle coefficient of performance, for every working conditions there are a certain value of generation temperature which its exergy performance of cycle achieves the maximum, the augmentation of output pressure of turbine is positively affected the cycle coefficient of performance contrary of the work produced in the turbine and the cycle exergy efficiency and the augmentation of condensation temperature is positively affected the cycle exergy efficiency and the work produced in the turbine contrary for cycle coefficient of performance and the augmentation of evaporation temperature is positively affected the cycle coefficient of performance and the cycle exergy efficiency contrary for the work produced in the turbine The results also show that the improvement of exergy efficiency of proposed cycle is 29.41% and 46% compared with the absorption cooling cycle with double and triple effect under the same operating conditions.
{"title":"Performance Investigation of Ejector Assisted Power Cooling Absorption Cycle","authors":"Billal Mebarki̇","doi":"10.5541/ijot.1247392","DOIUrl":"https://doi.org/10.5541/ijot.1247392","url":null,"abstract":"In this paper, new cycle is developed to generate simultaneously electrical and cooling power by placing a turbine between the generator and ejector in the conventional ejector-assisted absorption cooling cycle. The aim of developed cycle is to increase the exergy efficiency of cycle by adding an electrical power generation made it more environmentally friendly and reduce its dependents of fossil energy sources. The first, second laws of thermodynamic, mass and energy balance is applied for each cycle component and the constant mixing pressure ejector model is used to develop a numerical model of proposed cycle. The results depict that the augmentation of generation temperature is positively affected the work produced in the turbine contrary for cycle coefficient of performance, for every working conditions there are a certain value of generation temperature which its exergy performance of cycle achieves the maximum, the augmentation of output pressure of turbine is positively affected the cycle coefficient of performance contrary of the work produced in the turbine and the cycle exergy efficiency and the augmentation of condensation temperature is positively affected the cycle exergy efficiency and the work produced in the turbine contrary for cycle coefficient of performance and the augmentation of evaporation temperature is positively affected the cycle coefficient of performance and the cycle exergy efficiency contrary for the work produced in the turbine The results also show that the improvement of exergy efficiency of proposed cycle is 29.41% and 46% compared with the absorption cooling cycle with double and triple effect under the same operating conditions.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41340289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Knowing that from 2030 refrigerants used in refrigerating engineering should have a global warming potential (GWP) of less than 150. Searching for eco-friendly refrigerants with good performance and minimal environmental impact to substitute conventional working fluids such as R134a (GWP=1430) represents a great challenge for researchers. The present research aims to investigate and compare the performances of the eco-friendly refrigerant R13I1 (Zero GWP) used as a possible new working fluid in the ejector-expansion refrigeration cycle (EERC) with the commonly used R134a which has good performances but a high GWP. To reach this objective, a numerical program was developed using MATLAB software to evaluate the coefficient of performance (COP), the entrainment ratio (µ), the exergy destruction and the exergy efficiency for both refrigerants. Furthermore, the effect of the diffuser efficiency of the ejector on the COP and the compressor work was explored. Furthermore, the effect of the diffuser efficiency of the ejector on the COP, and the compressor work were explored. The simulation was realized for Tc selected between 30 and 55 °C and Te ranging between -10 and 10 °C. Results proved that the use of R13I1 as a working fluid in the EERC system exhibited a higher COP, µ, and exergy efficiency, as well as lower exergy destruction compared with R134a under the same operating temperatures. On another hand, the energetic analysis revealed that as Tc increases the COP and µ decrease. However, as Te varies from -10 and 10 °C, the COP and µ increase. Regarding exergy analysis, it should be noted that both exergy destruction and exergy efficiency are sensitively influenced by Tc more than Te. Overall, the study confirms that R13I1 could be a suitable substitute for the phase-out R134a in terms of performance and environmental protection.
{"title":"Performances Investigation of the Eco-friendly Refrigerant R13I1 used as Working Fluid in the Ejector-Expansion Refrigeration Cycle","authors":"Youcef Maalem, Youcef Tamene, H. Madani","doi":"10.5541/ijot.1263939","DOIUrl":"https://doi.org/10.5541/ijot.1263939","url":null,"abstract":"Knowing that from 2030 refrigerants used in refrigerating engineering should have a global warming potential (GWP) of less than 150. Searching for eco-friendly refrigerants with good performance and minimal environmental impact to substitute conventional working fluids such as R134a (GWP=1430) represents a great challenge for researchers. \u0000The present research aims to investigate and compare the performances of the eco-friendly refrigerant R13I1 (Zero GWP) used as a possible new working fluid in the ejector-expansion refrigeration cycle (EERC) with the commonly used R134a which has good performances but a high GWP. To reach this objective, a numerical program was developed using MATLAB software to evaluate the coefficient of performance (COP), the entrainment ratio (µ), the exergy destruction and the exergy efficiency for both refrigerants. Furthermore, the effect of the diffuser efficiency of the ejector on the COP and the compressor work was explored. Furthermore, the effect of the diffuser efficiency of the ejector on the COP, and the compressor work were explored. The simulation was realized for Tc selected between 30 and 55 °C and Te ranging between -10 and 10 °C. Results proved that the use of R13I1 as a working fluid in the EERC system exhibited a higher COP, µ, and exergy efficiency, as well as lower exergy destruction compared with R134a under the same operating temperatures. On another hand, the energetic analysis revealed that as Tc increases the COP and µ decrease. However, as Te varies from -10 and 10 °C, the COP and µ increase. Regarding exergy analysis, it should be noted that both exergy destruction and exergy efficiency are sensitively influenced by Tc more than Te. Overall, the study confirms that R13I1 could be a suitable substitute for the phase-out R134a in terms of performance and environmental protection.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42446928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The solid – liquid equilibria in n-tridecane is investigated by calculating phase diagrams and the thermodynamic quantities using the Landau phenomenological model. By expanding the free energy in terms of the order parameter of the solid phase, the phase line equations are fitted to the experimental data for the T – X and T – P phase diagrams from the literature. The temperature dependences of the thermodynamic quantities (order parameter ψ, susceptibility χ_ψ, free energy F, the heat capacity C, entropy S and the enthalpy H) are predicted for the n-tridecane from this model. Our results give that the slope dT⁄dP≅2 "K/MPa" for n-C13 to n-C17. ψ varies with T as ψ~(T-T_m )^(1⁄2) above T_m. It is linear for the 〖χ_ψ〗^(-1), S(T) and C(T), and quadratic for the F(T) and H(T) in n-tridecane. This indicates that the Landau model, describes the observed behaviour of the phase diagrams satisfactorily for the solid – liquid equilibria in n-tridecane. Predictions of the thermodynamic quantities can also be compared with the measurements and predictions of some other theoretical models. The pressure effect, in particular, on the solid – liquid equilibria in n-tridecane can also be investigated under the model studied here.
{"title":"Calculation of the Phase Diagrams (T – X and T – P) and the Thermodynamic Quantities for the Solid – Liquid Equilibria in n-tridecane","authors":"Özlem TARI İLGİN, H. Yurtseven","doi":"10.5541/ijot.1267822","DOIUrl":"https://doi.org/10.5541/ijot.1267822","url":null,"abstract":"The solid – liquid equilibria in n-tridecane is investigated by calculating phase diagrams and the thermodynamic quantities using the Landau phenomenological model. By expanding the free energy in terms of the order parameter of the solid phase, the phase line equations are fitted to the experimental data for the T – X and T – P phase diagrams from the literature. The temperature dependences of the thermodynamic quantities (order parameter ψ, susceptibility χ_ψ, free energy F, the heat capacity C, entropy S and the enthalpy H) are predicted for the n-tridecane from this model. Our results give that the slope dT⁄dP≅2 \"K/MPa\" for n-C13 to n-C17. ψ varies with T as ψ~(T-T_m )^(1⁄2) above T_m. It is linear for the 〖χ_ψ〗^(-1), S(T) and C(T), and quadratic for the F(T) and H(T) in n-tridecane. This indicates that the Landau model, describes the observed behaviour of the phase diagrams satisfactorily for the solid – liquid equilibria in n-tridecane. Predictions of the thermodynamic quantities can also be compared with the measurements and predictions of some other theoretical models. The pressure effect, in particular, on the solid – liquid equilibria in n-tridecane can also be investigated under the model studied here.","PeriodicalId":14438,"journal":{"name":"International Journal of Thermodynamics","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46318712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Serhat Yildirim, Sadık Ata, Huseyin Kurt, A. Kahraman
In this study, the solar Organic Rankine Cycle (ORC) system was analyzed to meet some of the electrical energy needed in large and medium-sized buildings and large enterprises such as hotels from solar energy. A simulation study was conducted for different districts in Türkiye that are rich in solar energy potential. These counties and the provinces they are affiliated with; Silifke-İçel, Alanya-Antalya, Bodrum-Muğla, Çeşme-İzmir. The power value transferred to the ORC was determined by considering the instantaneous radiation values and sunshine durations for the districts. The performance of solar ORC was determined by comparing fluids from three different organic fluid types. Organic fluids and types used in design; benzene-aromatic hydrocarbon, cyclohexane-alkane, octamethylcyclotetrasiloxane (D4)-siloxane. Considering the maximum electrical energy values obtained from Solar ORC in the summer months, it was seen that 205 MWh electricity generated was obtained for Silifke with benzene at a heat source temperature of 223 oC in July. Maximum solar parabolic trough collector (PTC) specific electric power value was determined as 59.52 W/m2 in Alanya district with benzene in June. When the four districts are evaluated together, it has been determined that benzene performs better than cyclohexane by 3.8% on average and 23% better than D4. When the annual electrical energy values are examined, the highest production was determined as 1625 MWh with benzene fluid in Alanya district.
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