Sally M. Smith^*, Brenton S. Taft^† , Jacob Moulton

Frontiers in Heat and Mass Transfer, Vol.5, pp. 1-9, 2014, DOI:10.5098/hmt.5.6

Abstract This study investigates the wettability of fluid-solid interactions of interest for oscillating heat pipe (OHP) applications. Measurements were taken using two techniques: the sessile drop method and capillary rise at a vertical plate. Tested surface materials include copper, aluminum, and Teflon PFA. The working fluids tested were water, acetone, R-134a, and HFO-1234yf. A novel low-pressure experimental setup was developed for refrigerant testing. Results show that the refrigerants have significantly lower hysteresis than the water and acetone-based systems, which is thought to lead to better heat transfer in OHP design. More >

Rongge Xiao^a,*, Yanwei Zhang^a , Xu Gao^b , Hongping Yu^c , Wangying Wei^a

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-8, 2020, DOI:10.5098/hmt.15.22

Abstract In order to improve DMR (double mixed refrigerant) liquefaction process and reduce operation cost of natural gas liquefaction plant, a four-stage DMR process optimization simulation calculation model was established through Aspen Hysys v8.4 and the purpose of the optimization model is achieved by using the segmented compression process in this paper. The minimum energy consumption and the highest exergy efficiency were used as the objective functions. By using the optimizer in HYSYS, the process parameters and ingredient proportion of the mixed refrigerant in the fourstage DMR process was optimized, and the best process parameters and ingredient proportion of the mixed… More >

Ammar Hassan Soheel, Omar Mahmood Jumaah, Ahmed Mustaffa Saleem^*

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-7, 2021, DOI:10.5098/hmt.17.21

Abstract This paper presents a simulation and investigation of the heat transfer coefficient, pressure drop, and thermal conductivity of two - phase flow. The simulation was performed of mixtures (Al₂O₃ nanoparticles with R134a refrigerant). The size of nanoparticles (Al₂O₃) which is used in this study is 30 nm and volume concentrations are 0.015 and 0.03. The two – phase flowing through a horizontal circular microchannel of (diameter 100 µm, and length 20 mm) under constant heat flux (3000 W/m²) and constant wall temperature (330 K), also in this study used the inlet temperature at -20 oC and mass flow rates are… More >

Vijay W. Bhatkar^a,*, Anirban Sur^b,*, Anindita Roy^b

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-7, 2022, DOI:10.5098/hmt.19.15

Abstract Versatile vapor compression refrigeration system is designed, developed and fabricated such that desired condensing and evaporating temperatures can be obtained by providing different electronic controls for superheating, subcooling, fan speed, air heaters and water heatersto use alternative refrigerants to R134a such as R1234ze, R152a, R600a, R290 and R290/R600a (50/50%) with conventional and minichannel condenser. All the refrigerant are tested for condensing temperature ranging from 40 °C to 55 °C while evaporating temperature changes from -10 °C to 15 °C for both condensers. The total exergy loss for main system components such as compressor, condenser, expansion valve and evaporator are calculated.… More >

Aparna Kottapallia , Ramakrishna Konijeti^b,*

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-11, 2022, DOI:10.5098/hmt.19.11

Abstract Scroll technology is widely used in refrigerators as compressors. This research paper presents the performance of a scroll-type expander derived from a scroll compressor. The research is carried out at low pressures. The effect of mechanical load on performance has been evaluated using compressed air as a working fluid. Two stages of the evaluation process are carried out in this research. In the first stage, the scroll expander model is numerically simulated using the CFD approach to predict the factors influencing the scroll expander performance. In the later stage, an experiment is carried out on a scroll-type expander prototype developed… More >

Rachedi Khadraoui¹, Latra Boumaraf^1,*, Philippe Haberschill²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.5, pp. 1115-1128, 2023, DOI:10.32604/fdmp.2022.022674

Abstract A theoretical investigation is presented about a double evaporator ejector refrigeration cycle (DEERC). Special attention is paid to take into account the influence of the sub-cooling and superheating effects induced by an internal heat exchanger (IHX). The ejector is introduced into the baseline cycle in order to mitigate the throttling process losses and increase the compressor suction pressure. Moreover, the IHX has the structure of a concentric counter-flow type heat exchanger and is intentionally used to ensure that the fluid at the compressor inlet is vapor. To assess accurately the influence of the IHX on the DEERC performance, a mathematical… More > Graphic Abstract

Yuchen Yang^1,2, Lin Ma^1,2,*, Jie Yu^1,2, Zewen Zhao^1,2, Pengfei You^1,2

Journal of Renewable Materials, Vol.11, No.3, pp. 1153-1179, 2023, DOI:10.32604/jrm.2022.022719

Abstract The use of nanorefrigerants in Organic Rankine Cycle (ORC) units is believed to affect the cycle environment performance, but backed with very few relevant studies. For this purpose, a life cycle assessment (LCA) has been performed for the ORC system using nanorefrigerant, the material and energy input, characteristic indicators and comprehensive index of environmental impact, total energy consumption and energy payback time (BPBT) of the whole life cycle of ORC system using Al₂O₃/R141b nanorefrigerant were calculated. Total environmental comprehensive indexes reveal that ECER-135 index decrease by 1.5% after adding 0.2% Al₂O₃ nanoparticles to R141b. Based on the contribution analysis and… More >

Xiao Wu^*, Zhaoting Wang, Longfei Dong, Yanping Xin, Tianshu Yu

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.1, pp. 25-36, 2023, DOI:10.32604/fdmp.2023.020953

Abstract The Mixed Refrigerant (MR) component is an important factor influencing the performances of natural gas liquefaction processes. However, there is a lack of systematic research about the utilization of propane pre-cooled (C3/MRC). In this paper, this mixed refrigerant cycle liquefaction process is simulated using the HYSYS software and the main influential parameters involved in the process are varied to analyze their influence on the liquefaction rate and power consumption. The results show that an effective way for lowering the power consumption of the compressor consists of reducing the flow through the compressor through optimization of the percentage of mixed refrigerant.… More >

Piyanut Saengsikhiao¹, Juntakan Taweekun^1,2,*, Kittinan Maliwan², Somchai Sae-ung², Thanansak Theppaya²

Energy Engineering, Vol.118, No.2, pp. 411-433, 2021, DOI:10.32604/EE.2021.012860

Abstract This paper presents the improvement of eco-friendly and power consumption saving refrigerants for refrigeration systems. The novel azeotropic refrigerant mixtures of HFCs and HCs can replace refrigeration systems, and using the R134, R32, R125, and R1270 refrigerants in several compositions found using the decision tree function of the RapidMiner software (which came first in the KDnuggets annual software poll). All refrigerant results are mixed of POE, which is A1 classification refrigerant, non-flammable, and innocuous refrigerant, and using REFPROP software and CYCLE_D-HX software are under the CAN/ANSI/AHRI540 standards. The boiling point of the new refrigerant mix R-No.595 is 4.58%, lower than… More >

Daoming Shen^1,*, Xia Zhang¹, Wei He¹, Jinhong Xia¹, Songtao Xue²

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1259-1272, 2020, DOI:10.32604/fdmp.2020.010951

Abstract Experiments about heat transfer in the presence of a two-phase flow due to the condensation of a R1234yf refrigerant have been performed considering a smooth tube and two micro-fin tubes. The following experimental conditions have been considered: Condensation temperatures of 40°C, 43°C and 45°C, mass fluxes of 500–900 kg/(m² ·s), vapor qualities at the inlet and outlet of the heat transfer tube in the ranges 0.8–0.9 and 0.2–0.3, respectively. These tests have shown that: (1) The heat transfer coefficient increases with decreasing the condensation temperature and on increasing the mass flux; (2) The heat transfer coeffi- cient inside the micro-fin… More >