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Maoqiong Gong - One of the best experts on this subject based on the ideXlab platform.
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measurements of pρtx and Specific Heat Capacity cv for r290 r1243zf binary mixtures at temperatures from 292 to 350 k and pressures up to 11 mpa
International Journal of Refrigeration-revue Internationale Du Froid, 2020Co-Authors: Owe Sheng, Qua Zhong, Xueqiang Dong, Yanxing Zhao, Jingzhou Wang, Maoqiong Gong, Ju SheAbstract:Abstract In this paper, isochoric pρTx and Specific Heat Capacity (cv) for (R290 + R1243zf) binary mixtures were measured using an adiabatic batch calorimeter with intermittent Heating. A total of 57 pρTx data points over temperatures from (292 to 350) K and 82 isochoric Specific Heat Capacity data points over temperatures from (299 to 350) K were obtained for liquid with mole fractions of R290 at (0.788, 0.606, 0.435 and 0.170). The standard uncertainties were estimated to be 12 mK for temperature, 5 kPa for pressure, 0.30% for density and 0.96% for isochoric Specific Heat Capacity. The experimental density and Heat Capacity data agree well with the Helmholtz equation of state (EOS) developed by Bell and Lemmon (2016), and the average absolute relative deviation (AARD) are 0.27% and 1.01%, respectively. Comparisons of the present cv data with values calculated by the generalized equation developed by Zhong et al. (2019a) was carried out as well, and the results show good agreements with deviations varying from −3.00% to 3.16% and the average absolute relative deviation (AARD) of 0.91%.
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the isochoric Specific Heat Capacity for r1234ze e at temperatures from 237 to 349 k and pressures up to 9 2 mpa
The Journal of Chemical Thermodynamics, 2020Co-Authors: Le Wang, Qua Zhong, Xueqiang Dong, Yanxing Zhao, Owe Sheng, Jie Song, Maoqiong GongAbstract:Abstract In this work, the isochoric Specific Heat Capacity (cv) of trans-1,3,3,3-tetrafluoropropene (R1234ze(E)) in the compressed liquid states were measured using an adiabatic batch calorimeter. The temperatures ranged from (237 to 349) K and pressures up to 9.2 MPa. Measurements were obtained for a total of 112 state conditions on 22 pseudo-isochores. The standard uncertainties of temperatures, pressures and isochoric Specific Heat capacities were estimated to be 12 mK, 5 kPa and 0.98%, respectively. The experimental cv values for R1234ze(E) are compared with three equations, including two Helmholtz equations of state (EOSs) and a generalized equation based on corresponding state principle. The data in this work show good agreement, and the average absolute relative deviations are 1.37%, 1.27% and 1.59% for the above three equations, respectively.
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thermodynamic properties of r1234yf r290 isochoric pρtx and Specific Heat Capacity cv measurements and an equation of state
The Journal of Chemical Thermodynamics, 2019Co-Authors: Qua Zhong, Xueqiang Dong, Yanxing Zhao, Jingzhou Wang, Haiyang Zhang, Hao Guo, Ju She, Maoqiong GongAbstract:Abstract In this paper, isochoric pρTx and Specific Heat Capacity cv for (R1234yf + R290) binary mixtures were measured using an adiabatic batch calorimeter with intermittent Heating. A total of 42 pρTx data points over temperatures from (254.28 to 348.30) K and 89 isochoric Specific Heat Capacity data points over temperatures from (255.48 to 347.55) K were obtained for liquid (R1234yf + R290) with mole fractions of R1234yf at (0.825, 0.607, 0.521 and 0.285). The standard uncertainties were estimated to be 10 mK for temperature, 5 kPa for pressure, 0.3% for density and 1.0% for isochoric Specific Heat Capacity. The experimental pρTx data were correlated by an empirical Tait equation with average absolute relative deviation of 0.19%. A Helmholtz energy equation of state based on the multi-fluid approximations model was developed for (R1234yf + R290) using the present and available experimental data. Eleven mixture rules are employed and the optimal Helmholtz energy equation of state calculates the density, VLE and isochoric Specific Heat Capacity properties with sufficient accuracy. The compressed liquid density and isochoric Specific Heat Capacity data in this work are well represented with average absolute relative deviation of 0.21% and 0.66%, respectively.
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adiabatic calorimeter for isochoric Specific Heat Capacity measurements and experimental data of compressed liquid r1234yf
The Journal of Chemical Thermodynamics, 2018Co-Authors: Qua Zhong, Xueqiang Dong, Yanxing Zhao, Jingzhou Wang, Haiyang Zhang, Hao Guo, Ju She, Maoqiong GongAbstract:Abstract In this paper, an adiabatic calorimeter has been developed to measure the isochoric Specific Heat Capacity of compressed liquid. A spherical bomb with platinum resistance thermometer inserted was used to hold the measured liquid and two adiabatic shields were arranged to reduce the Heat loss of thermal radiation. The isochoric Specific Heat Capacity of liquid propane was measured over temperatures from (236 to 340) K and pressures up to 14 MPa. Satisfactory agreement with published Heat Capacity data is found and the reliability of the experimental setup is verified. Moreover, the experimental isochoric Specific Heat Capacity data of liquid R1234yf were obtained in the temperatures from (240 to 341) K and pressures up to 13 MPa. The standard uncertainties were estimated to be 10 mK for temperature, 5 kPa for pressure and 1.0% for isochoric Specific Heat Capacity. The data of R1234yf are represented by two Helmholtz equations of state with average absolute relative deviations of 2.0% and 1.3%, respectively. Comparisons are made between the Helmholtz equations of state and the cubic equations of state for the calculation of the Specific Heat Capacity property. The Helmholtz equations of state give a better description than the cubic equations of state, and the Peng–Robinson equation of state performs slightly better than the Patel–Teja and Soave–Redlich–Kwong equations of state.
Shigeru Koyama - One of the best experts on this subject based on the ideXlab platform.
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isochoric Specific Heat Capacity of trans 1 3 3 3 tetrafluoropropene hfo 1234ze e and the hfo 1234ze e co2 mixture in the liquid phase
Journal of Chemical & Engineering Data, 2011Co-Authors: Kenichi Yamaya, Atsushi Matsuguchi, Noboru Kagawa, Shigeru KoyamaAbstract:The isochoric Specific Heat Capacity (cV) of trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)) and mole fraction x = 0.489 HFO-1234ze(E) + (1 − x) = 0.511 CO2 in the liquid phase were measured with a twin-cell type adiabatic calorimeter. The sample purity of HFO-1234ze(E) and CO2 was certified to have a minimum purity of 0.9996 mole fraction and 0.99999 mole fraction respectively by gas chromatographic analysis. The measurements were obtained for temperatures ranging from (270 to 425) K and at pressures up to 30 MPa. Temperatures were measured with a platinum resistance thermometer on the bottom of each cell and were reported based on the International Temperature Scale of 1990 (ITS-90). Sample pressures were measured with a quartz crystal transducer. Densities were calculated from the volume of the calorimeter cell and the sample mass. The expanded uncertainty (with a coverage factor k = 2) of temperature measurements is 13 mK and 8 kPa for pressure measurements. The expanded relative uncertainty of densi...
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Specific Heat Capacity of a single component adsorbent adsorbate system
Applied Physics Letters, 2007Co-Authors: Anuthosh Chakraborty, Idyut Bara Saha, Shigeru KoyamaAbstract:A thermodynamic framework for calculating the Specific Heat Capacity (Cp) of a single component adsorbent+adsorbate system has been derived and developed using the classical thermodynamics, and these are essential for the design of adsorption processes. The derived formulation of the Cp is compared with the experimentally measured Cp of adsorbent+adsorbate systems. The purpose of this letter is to fill up the information gap with respect to the state of adsorbed phase to dispel the confusion as to what is the actual state of the adsorbed phase.
Yukihiro Higashi - One of the best experts on this subject based on the ideXlab platform.
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measurements of the isobaric Specific Heat capacities for trans 1 3 3 3 tetrafluoropropene hfo 1234ze e in the liquid phase
Journal of Chemical & Engineering Data, 2010Co-Authors: Katsuyuki Tanaka, Gen Takahashi, Yukihiro HigashiAbstract:The isobaric Specific Heat Capacity of trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)) in the liquid phase was measured using a metal-bellows calorimeter. Twenty-six data points were obtained in the temperature range from (310 to 370) K and pressure range from (2 to 5) MPa. The relative experimental uncertainty of the isobaric Specific Heat Capacity was estimated to be 5 %. On the basis of the present data, the correlation of the isobaric Specific Heat Capacity in the liquid phase was formulated as functions of temperature and pressure. The Heat capacities of saturated liquid were derived from this correlation by substituting the vapor pressure.
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measurements of the isobaric Specific Heat Capacity and density for hfo 1234yf in the liquid state
Journal of Chemical & Engineering Data, 2010Co-Authors: Katsuyuki Tanaka, Yukihiro Higashi, Ryo AkasakaAbstract:The isobaric Specific Heat Capacity and density of the HFO-1234yf (2,3,3,3-tetrafluoropropene, CH2═CFCF3) in the liquid state have been measured in the temperature range from (310 to 360) K at pressures up to 5 MPa. The uncertainties in temperature, pressure, isobaric Specific Heat Capacity, and density measurements were estimated to be less than 5 mK, 3 kPa, 5 %, and 0.2 %, respectively. A sample with purity of 99.99 mol % or greater was used for the measurement. Experimental values for the isobaric Specific Heat Capacity were correlated as a function of pressure along isotherms, and those for density were correlated as functions of pressure and temperature. In addition, the saturated liquid isobaric Specific Heat Capacity and density were obtained from extrapolation of these correlations to the vapor pressure.
Tawfik A Saleh - One of the best experts on this subject based on the ideXlab platform.
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predicting the Specific Heat Capacity of alumina ethylene glycol nanofluids using support vector regression model optimized with bayesian algorithm
Solar Energy, 2019Co-Authors: Ibrahim Olanrewaju Alade, Mohd Amiruddin Abd Rahma, Tawfik A SalehAbstract:Abstract Nanofluids are now considered the most essential constituent of solar thermal collector due to their superior thermal performance over conventional fluids. An accurate determination of the thermal efficiency of the solar collector depends on the value of the Specific Heat Capacity of the nanofluid. So far, limited attention has been devoted towards accurate modelling of Specific Heat Capacity of nanofluids C P nf despite their relevance in many solar energy-related applications. Surprisingly, there are only two main analytic models for estimating the C P nf in the literature. In most of the reports, these models have shown considerable inconsistencies for predicting the values of C P nf . Moreover, the modelling performance of these models necessitates the need to develop accurate models for the prediction of C P nf . Herein, a Bayesian support vector regression (BSVR) model is proposed to estimate the Specific Heat Capacity of Al2O3/ethylene glycol nanofluid. The model proposed was trained on eighty-four (84) experimental datasets and its predictive accuracy was validated on seventeen (17) new test set. The BSVR model exhibits high accuracy as measured by the values of Pearson's correlation coefficient and the absolute average relative deviation (AARD) of 99.95% and 0.1888, respectively. Remarkably, the accuracy obtained from the proposed BSVR model is an order of magnitude better than existing theoretical models. The proposed technique and model will be useful towards a more reliable and accurate computation of the efficiency of solar collectors.
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modeling and prediction of the Specific Heat Capacity of al2 o3 water nanofluids using hybrid genetic algorithm support vector regression model
Nano-Structures and Nano-Objects, 2019Co-Authors: Ibrahim Olanrewaju Alade, Mohd Amiruddin Abd Rahma, Tawfik A SalehAbstract:Abstract In this study, the Specific Heat Capacity of Alumina (Al2O3)/water nanofluid has been accurately evaluated using genetic algorithm/support vector regression (GA/SVR) model at volume fractions of 3.7–9.3%. The proposed (genetic algorithm/support vector regression) GA/SVR model was formulated using volume fractions and Specific Heat capacities of the alumina nanoparticles. The developed GA/SVR model is very accurate as determined from 99.998% correlation coefficient with experimentally obtained data and also has a root mean square error of 0.0014. Furthermore, the obtained results from the GA/SVR were compared with existing analytic models. Remarkably, the proposed model achieved an order of magnitude improvement over the model based on thermal equilibrium (Model II) and a two order of magnitude improvement over the model based on simple mixing rule for ideal gases (model I). Given the improvement in the accuracy, the proposed model would be useful for rapid and highly accurate estimation of the Specific Heat Capacity of alumina/water nanofluids.
Debjyoti Anerjee - One of the best experts on this subject based on the ideXlab platform.
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a soft computing approach for estimating the Specific Heat Capacity of molten salt based nanofluids
Journal of Molecular Liquids, 2019Co-Authors: Muhammed A Hassa, Debjyoti AnerjeeAbstract:Abstract Despite the promising potential of nanofluids as Heat transfer and energy storage media, determination of their thermal behavior and properties need significant experimentation. Considering the relatively high costs of such fluids and the time-consuming procedures for synthesizing them and measuring their characteristics, machine learning techniques can be powerful tools for simulating their behaviors in the unstudied combinations of operating conditions. In this study, a machine learning model has been developed for the first time in the literature - to simulate and predict the Specific Heat Capacity of a molten nitrate salt mixture seeded with silica, alumina and titania nanoparticles. A multilayer perceptron neural network (ANN) was selected among 1920 ANNs with different architectural features. With a prediction R2 value of 0.9998, the suggested model was found to provide much superior predictions (and validated against experimental data) as compared to the classic analytical models. The model developed in this study can, therefore, be used for estimating the values of Specific Heat Capacity for nanofluid samples - based on the temperature and mass fraction of the nanoparticles, as well as the average (or nominal size) of the nanoparticles. The soft-computing technique itself was evaluated under extreme training conditions and it was found that the algorithm can adapt to new data sets with maximum MAPE of 2% and can enable excellent quality of predictions (R2 > 0.95) when trained with
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effect of solvent on Specific Heat Capacity enhancement of binary molten salt based carbon nanotube nanomaterials for thermal energy storage
International Journal of Thermal Sciences, 2015Co-Authors: Debjyoti AnerjeeAbstract:Abstract The Specific Heat Capacity of a binary molten salt-based carbon nanotube nanomaterial was experimentally measured in both solid and liquid phases. The effect of the solvent on the Specific Heat Capacity was examined for a wide range of chemical compositions for a binary carbonate salt mixture. The binary salt mixture consisted of lithium carbonate and potassium carbonate. Multi-walled carbon nanotubes were dispersed in the solvent to synthesize the nanomaterials. A surfactant, gum arabic, at 1% mass concentration with respect to the solvent was added to disperse the carbon nanotubes homogeneously in the salt mixture. The results indicated that the Specific Heat Capacity of the carbonate salt mixtures was significantly enhanced by adding the carbon nanotubes in the solid and liquid phases. Moreover, the enhanced Specific Heat Capacity was affected by the chemical composition of the salt mixtures. Furthermore, molecular dynamics simulations were used to examine the effects of different chemical compositions of the binary salt mixtures with nanotubes on the Specific Heat capacities of the nanomaterials.
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effect of formation of long range secondary dendritic nanostructures in molten salt nanofluids on the values of Specific Heat Capacity
International Journal of Heat and Mass Transfer, 2015Co-Authors: Hani Tiznobaik, Debjyoti Anerjee, Donghyu ShiAbstract:Abstract Several studies in recent literature have demonstrated the enhancement of Specific Heat Capacity (Cp) of molten-salts on doping with minute concentration of nanoparticles, especially when the synthesis conditions enabled the formation of stable colloidal suspensions (which are also known as “molten-salt nanofluids”). In this study we present additional evidence in support of theory proposed earlier in the literature that stable colloidal suspensions of nanoparticles in a molten-salt medium induces the preferential surface adsorption of the constitutive chemical species in the salt mixture which in turn leads to the nucleation of solid phase of the molten salt (with perhaps a different chemical composition than in the bulk phase) on the nanoparticle surface. The surface adsorbed salt species leads to the nucleation and growth of a semi-solid layer of dendritic shaped phase (dendritic shaped secondary “long range” nanostructures). Incidentally, such nanostructures were not observed in electron microscopy images for samples of pure molten-salt mixtures subjected to control experiments (i.e., without nanoparticles). Hence, this study conclusively demonstrates that the existence of these nanostructures is primarily responsible for the enhancement of Specific Heat Capacity. In this study, three different types of nanoparticles are dispersed in the same molten-salt mixture (“base fluid”) and the experimentally measured values of Specific Heat Capacity enhancements obtained in this study are correlated to the formation of dendritic nanostructures that are observed in the images obtained from the electron microscopy of the molten-salt nanomaterial samples.
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enhanced Specific Heat Capacity of molten salt based carbon nanotubes nanomaterials
Journal of Heat Transfer-transactions of The Asme, 2015Co-Authors: Debjyoti AnerjeeAbstract:This study aims to investigate the Specific Heat Capacity of a carbonate salt eutectic-based multiwalled carbon nanomaterial (or high temperature nanofluids). The Specific Heat Capacity of the nanomaterials was measured both in solid and liquid phase using a differential scanning calorimetry (DSC). The effect of the carbon nanotube (CNT) concentrations on the Specific Heat Capacity was examined in this study. The carbonate molten salt eutectic with a high melting point around 490 °C, which consists of lithium carbonate of 62% and potassium carbonate of 38% by the molar ratio, was used as a base material. Multiwalled CNTs were dispersed in the carbonate salt eutectic. A surfactant, sodium dodecyl sulfate (SDS) was utilized to obtain homogeneous dispersion of CNT into the eutectic. Four different concentrations (0.1, 0.5, 1, and 5 wt.%) of CNT were employed to explore the Specific Heat Capacity enhancement of the nanomaterials as the concentrations of the nanotubes varies. In result, it was observed that the Specific Heat Capacity was enhanced by doping with the nanotubes in both solid and liquid phase. Additionally, the enhancements in the Specific Heat Capacity were increased with increase of the CNT concentration. In order to check the uniformity of dispersion of the nanotubes in the salt, scanning electron microscopy (SEM) images were obtained for pre-DSC and post-DSC samples. Finally, the Specific Heat Capacity results measured in present study were compared with the theoretical prediction.
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effect of dispersion homogeneity on Specific Heat Capacity enhancement of molten salt nanomaterials using carbon nanotubes
Journal of Solar Energy Engineering-transactions of The Asme, 2015Co-Authors: Debjyoti AnerjeeAbstract:The Specific Heat Capacity of a carbonate salt eutectic-based carbon nanotube nanomaterial was measured in present study. Differential scanning calorimeter (DSC) was used to measure the Specific Heat Capacity of the nanomaterials. The Specific Heat Capacity value in liquid phase was compared with that of a pure eutectic. A carbonate salt eutectic was used as a base material, which consists of lithium carbonate and potassium carbonate by 62:38 molar ratio. Multiwalled carbon nanotubes (CNT) at 1% mass concentration were dispersed in the molten salt eutectic. In order to find an appropriate surfactant for synthesizing molten salt nanomaterials, three surfactants, sodium dodecyl benzene sulfonate (SDBS), sodium dodecyl sulfate (SDS), and gum arabic (GA), at 1% mass concentration with respect to the salt eutectic were added. In preparation of dehydrated nanomaterials, water was evaporated by Heating vials on a hot plate. Three different temperature conditions (120, 140, and 160 °C) were employed to investigate the effect of dispersion homogeneity of the nanotubes in the base material on the Specific Heat Capacity of the nanomaterials. It is expected that the amount of agglomerated nanotubes decreases with increase of evaporation temperature (shorter elapsed time for evaporation). The results showed that the Specific Heat Capacity of the nanomaterials was enhanced up to 21% in liquid phase. Additionally, it was found that the Specific Heat Capacity enhancement of the nanomaterials, which contained SDS, was more sensitive to the evaporation time. Also, it can be decided that GA is the most appropriate to disperse CNT into the aqueous salt solution. Finally, CNT dispersion was confirmed with scanning electron microscope (SEM) images for pre-DSC and post-DSC samples. Furthermore, theoretical predictions of the Specific Heat Capacity were compared with the experimental results obtained in present study.
