scholarly journals Thermophysical properties of working fluids for binary geothermal cycles. Final report

1984 ◽  
Author(s):  
D.E. Diller ◽  
J.S. Gallagher ◽  
B. Kamgar-Parsi ◽  
G. Morrison ◽  
J.M.H. Levelt Sengers ◽  
...  
Keyword(s):  
Thermophysical Properties ◽  
Final Report ◽  
Working Fluids

scholarly journals Boiling Heat Transfer Evaluation in Nanoporous Surface Coatings

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3383
Author(s):  
Uzair Sajjad ◽  
Imtiyaz Hussain ◽  
Muhammad Imran ◽  
Muhammad Sultan ◽  
Chi-Chuan Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Deep Learning ◽  
Thermophysical Properties ◽  
Boiling Heat Transfer ◽  
Parameters Estimation ◽  
Learning Method ◽  
Working Fluids ◽  
Coated Surfaces ◽  
Nanoporous Surfaces

The present study develops a deep learning method for predicting the boiling heat transfer coefficient (HTC) of nanoporous coated surfaces. Nanoporous coated surfaces have been used extensively over the years to improve the performance of the boiling process. Despite the large amount of experimental data on pool boiling of coated nanoporous surfaces, precise mathematical-empirical approaches have not been developed to estimate the HTC. The proposed method is able to cope with the complex nature of the boiling of nanoporous surfaces with different working fluids with completely different thermophysical properties. The proposed deep learning method is applicable to a wide variety of substrates and coating materials manufactured by various manufacturing processes. The analysis of the correlation matrix confirms that the pore diameter, the thermal conductivity of the substrate, the heat flow, and the thermophysical properties of the working fluids are the most important independent variable parameters estimation under consideration. Several deep neural networks are designed and evaluated to find the optimized model with respect to its prediction accuracy using experimental data (1042 points). The best model could assess the HTC with an R2 = 0.998 and (mean absolute error) MAE% = 1.94.

scholarly journals Thermophysical properties of working fluids for binary geothermal cycles

1985 ◽  
Author(s):  
D E Diller ◽  
J S Gallagher ◽  
B Kamgar-Parsi ◽  
G Morrison ◽  
J C Rainwater ◽  
...  
Keyword(s):  
Thermophysical Properties ◽  
Working Fluids

Performance Analysis of Near-Critical and Subcritical Organic Rankine Cycle

2013 ◽  
Vol 448-453 ◽  
pp. 3270-3276
Author(s):  
Yu Ping Wang ◽  
Yi Wu Weng ◽  
Ping Yang ◽  
Lei Tang
Keyword(s):  
Performance Analysis ◽  
Thermophysical Properties ◽  
Thermodynamic Model ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Vapor Generation ◽  
Working Fluids ◽  
The Difference ◽  
Better Than

In this paper, three typical working fluids were selected for the near-critical ORC and subcritical ORC. The difference of performance between the near-critical ORC and subcritical ORC was analyzed by establishing the thermodynamic model. The reason for difference was analyzed in terms of the thermophysical properties. The results indicate that the performance of the near-critical ORC is better than the subcritical ORC. The net absorbed heat, net power and efficiency of the near-critical ORC vary slowly with the vapor generation temperature, which means that the near-critical ORC has good off-design performance. The dry working fluid R236fa is best adapted for the near-critical ORC among the three working fluids. The singular performance of the near-critical ORC depends on the properties of latent heat and type of working fluid in near-critical region.

The Effects of Working Fluid on the Heat Transport Capacity of a Microheat Pipe

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
D. Sugumar ◽  
Kek-Kiong Tio
Keyword(s):  
Surface Tension ◽  
Heat Transport ◽  
Cross Section ◽  
Thermophysical Properties ◽  
Dynamic Viscosity ◽  
Working Fluid ◽  
Transport Capacity ◽  
Working Fluids ◽  
Triangular Cross Section ◽  
Operating Temperatures

The effects of the thermophysical properties of the working fluid on the performance of a microheat pipe of triangular cross section are investigated. For this purpose, five different working fluids are selected: water, hepthane, ammonia, methanol, and ethanol. For operating temperatures ranging from 20°Cto100°C, it is found that the behavior of the heat transport capacity is dominated by a property of the working fluid, which is equal to the ratio of the surface tension and dynamic viscosity σ∕μl. This property has the same dimension as velocity and can be interpreted as a measure of the working fluid’s rate of circulation, which can be provided by capillarity after overcoming the effect of viscosity. Of the five working fluids selected, ammonia is preferable for operating temperatures below 50°C since it yields the highest heat transport capacity; however, water is the preferred working fluid for temperatures above 50°C.

scholarly journals Carbon-Based Nanofluids and Their Advances towards Heat Transfer Applications—A Review

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1628
Author(s):  
Naser Ali ◽  
Ammar M. Bahman ◽  
Nawaf F. Aljuwayhel ◽  
Shikha A. Ebrahim ◽  
Sayantan Mukherjee ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermophysical Properties ◽  
Nuclear Reactor ◽  
Dispersion Stability ◽  
Future Research ◽  
Thermal Systems ◽  
Working Fluids ◽  
Measuring Techniques ◽  
Set Up ◽  
Carbon Based

Nanofluids have opened the doors towards the enhancement of many of today’s existing thermal applications performance. This is because these advanced working fluids exhibit exceptional thermophysical properties, and thus making them excellent candidates for replacing conventional working fluids. On the other hand, nanomaterials of carbon-base were proven throughout the literature to have the highest thermal conductivity among all other types of nanoscaled materials. Therefore, when these materials are homogeneously dispersed in a base fluid, the resulting suspension will theoretically attain orders of magnitude higher effective thermal conductivity than its counterpart. Despite this fact, there are still some challenges that are associated with these types of fluids. The main obstacle is the dispersion stability of the nanomaterials, which can lead the attractive properties of the nanofluid to degrade with time, up to the point where they lose their effectiveness. For such reason, this work has been devoted towards providing a systematic review on nanofluids of carbon-base, precisely; carbon nanotubes, graphene, and nanodiamonds, and their employment in thermal systems commonly used in the energy sectors. Firstly, this work reviews the synthesis approaches of the carbon-based feedstock. Then, it explains the different nanofluids fabrication methods. The dispersion stability is also discussed in terms of measuring techniques, enhancement methods, and its effect on the suspension thermophysical properties. The study summarizes the development in the correlations used to predict the thermophysical properties of the dispersion. Furthermore, it assesses the influence of these advanced working fluids on parabolic trough solar collectors, nuclear reactor systems, and air conditioning and refrigeration systems. Lastly, the current gap in scientific knowledge is provided to set up future research directions.

scholarly journals Assessment on Performance advancement utilizing nanofluid as additional fluid in a Refrigeration System

2021 ◽  
Vol 9 (8) ◽  
pp. 1205-1210
Keyword(s):  
Performance Improvement ◽  
Thermophysical Properties ◽  
Refrigeration System ◽  
Working Fluids ◽  
Refrigeration Equipment ◽  
Overall Performance ◽  
Hybrid Nanofluids ◽  
Refrigeration Machine

The performance of the refrigeration machine needs to be increased, which usually may be carried out by changing the unit or the properties of primary and additional working fluids. Currently, nanofluids or hybrid nanofluids possess obtained curiosity in various engineering areas scheduled to it has the superb thermophysical properties, which will be quickly applied in refrigeration equipment by various functions for overall performance improvement. This paper assesses and then summarizes the latest research carried out on the consumption of nanofluids in the refrigeration machine as the supplementary liquid is mentioned. At last, the difficulties and possibilities for upcoming study are determined, which will be beneficial for the beginners and then concerns in this discipline.

Sign in / Sign up

Export Citation Format

Share Document