The cubic-plus-association equation of state for hydrofluorocarbons, hydrofluoroolefins, and their binary mixtures

Yang, Fufang; Chu, Qingfu; Liu, Qiang; Duan, Yuan-Yuan; Yang, Zhen

doi:10.1016/j.ces.2019.115182

Cited by 18 publications

(19 citation statements)

References 121 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is shown that the percentage of C v r from the dipolar term and the ratio of C v r / C p r decrease with the increasing temperature. That means the dipole–dipole contribution to C p r probably becomes less important at higher temperatures, which may be due to the destruction of the orientational order of the molecules and the domination of molecular motion when temperature increases. In addition, according to the expressions of SRK and dipolar terms, we can know that the SRK contribution to C v r is related to T –1/2 , while the dipolar contribution is roughly related to T –2 .…”

Section: Results and Discussionmentioning

confidence: 99%

Quantification of Dipolar Contribution and Modeling of Green Polar Fluids with the Polar Cubic-Plus-Association Equation of State

Zhu

Liu

et al. 2021

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

Water, alcohols, ketones, esters, and ionic liquids are usually ranked as green solvents. There is still no consensus how to model these substances in the best manner due to their strong polarities. In this work, with a newly developed polar Cubic-Plus-Association equation of state (PCPA EoS), the influence of the dipole–dipole interaction on thermophysical properties is investigated for associating fluids (water and alcohols), polar nonassociating fluids (hydrogen sulfide, ketones, and esters), and ionic liquids. Special attention is paid to the heat capacity, which is difficult to model as a so-called second-order derivative property. The correlation capabilities of PCPA and CPA are first compared for vapor pressure, liquid density, and heat capacity for a primary evaluation of the dipole–dipole interaction. Then the contributions to residual heat capacity are estimated and compared for the individual terms of PCPA reflecting different molecular interactions. It is found that the contributions from the dipole–dipole interaction are negligible for associating compounds, while they are very important for both polar nonassociating fluids and ionic liquids as accurate heat capacities can be correlated only after they are counted in the model.

show abstract

Section: Results and Discussionmentioning

confidence: 99%

Quantification of Dipolar Contribution and Modeling of Green Polar Fluids with the Polar Cubic-Plus-Association Equation of State

Zhu

Liu

et al. 2021

ACS Sustainable Chem. Eng.

View full text Add to dashboard Cite

show abstract

“…These equations added more flexible temperature dependence to the attractive parameter a . There are now a very large number of cubic equations of state; they continue to be developed and used, including a recent application to HFCs and HFOs . A review of the cubic EOS is provided by Lopez-Echeverry et al…”

Section: Evolving Property Models and The Refprop Databasementioning

confidence: 99%

“…There are now a very large number of cubic equations of state; they continue to be developed and used, including a recent application to HFCs and HFOs. 91 A review of the cubic EOS is provided by Lopez-Echeverry et al 92 The refrigeration industry, however, often used the Martin-Hou 93 equation of state, which retains the van der Waals repulsive term but introduces a more complex attractive term:…”

Section: Evolving Property Models and Thementioning

confidence: 99%

(R)Evolution of Refrigerants

2020

View full text Add to dashboard Cite

As we enter the "fourth generation" of refrigerants, we consider the evolution of refrigerant molecules, the everchanging constraints and regulations that have driven the need to consider new molecules, and the advancements in the tools and property models used to identify new molecules and design equipment using them. These separate aspects are intimately intertwined and have been in more-or-less continuous development since the earliest days of mechanical refrigeration, even if sometimes out-of-sight of the mainstream refrigeration industry. We highlight three separate, comprehensive searches for new refrigerantsin the 1920s, the 1980s, and the 2010sthat sometimes identified new molecules, but more often, validated alternatives already under consideration. A recurrent theme is that there is little that is truly new. Most of the "new" refrigerants, from R-12 in the 1930s to R-1234yf in the early 2000s, were reported in the chemical literature decades before they were considered as refrigerants. The search for new refrigerants continued through the 1990s even as the hydrofluorocarbons (HFCs) were becoming the dominant refrigerants in commercial use. This included a return to several long-known natural refrigerants. Finally, we review the evolution of the NIST REFPROP database for the calculation of refrigerant properties.

show abstract

“…1 and 2, respectively. The organic working fluid coming out of the heater (2-3) after undergoing high-pressure throttle valve (3-4) enters into the vapor separator to achieve gas-liquid separation (4)(5)8). Dry saturated vapor is discharged from the top of the separator into the turbine and expands (5)(6).…”

Section: Ihe-ofc Systemmentioning

confidence: 99%

“…The large-scale consumption of fossil fuel has led to the destruction and pollution of the global ecological environment [1,2,3]. To reduce pollution and the consumption of fossil fuel, the utilization and development of clean energy have become particularly important [4]. Geothermal water is obtained from the depths of the earth.…”

Section: Introductionmentioning

confidence: 99%

Thermal performance analysis of organic flash cycle using R600A/R601A mixtures with internal heat exchanger

Huang

Zhang

et al. 2021

Therm sci

View full text Add to dashboard Cite

In this study, the thermal performance of an internal heat exchanger-organic flash cycle system driven by geothermal water was investigated.R600a/R601a mixtures were selected as the working fluid. The effects of the mole fraction of mixtures on the heat absorption capacity of the heater, the temperature rise of cold working fluid in the internal heat exchanger, net power output, thermal efficiency, and electricity generation costs were analyzed. The net power outputs, electricity generation costs, and thermal efficiency of the internal heat exchanger-organic flash cycle and simple organic flash cycle systems were compared. Results showed that the system using theR600a/R601a mixtures (0.7/0.3mole fraction) has the largest net power output, which increased the net power output by 3.68% and 42.23% over the R601a and R600a systems, respectively. WhentheR600a mole fraction was 0.4, the electricity generation costs reduction of the internal heat exchanger-organic flash cycle system was the largest (1.77% compared with the simple organic flash cycle system).The internal heat exchanger can increase the thermal efficiency of organic flash cycle, but the net power output does not necessarily increase.

show abstract

The cubic-plus-association equation of state for hydrofluorocarbons, hydrofluoroolefins, and their binary mixtures

Cited by 18 publications

References 121 publications

Quantification of Dipolar Contribution and Modeling of Green Polar Fluids with the Polar Cubic-Plus-Association Equation of State

Quantification of Dipolar Contribution and Modeling of Green Polar Fluids with the Polar Cubic-Plus-Association Equation of State

(R)Evolution of Refrigerants

Thermal performance analysis of organic flash cycle using R600A/R601A mixtures with internal heat exchanger

Contact Info

Product

Resources

About