Qiuyang Cheng^1,2,3, Lijun You^3,*, Cheng Chang^1,2, Weiyang Xie^1,2, Haoran Hu^1,2, Xingchen Wang^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.7, pp. 1441-1462, 2024, DOI:10.32604/fdmp.2024.051200 - 23 July 2024

Abstract Horizontal well drilling and multi-stage hydraulic fracturing technologies are at the root of commercial shale gas development and exploitation. During these processes, typically, a large amount of working fluid enters the formation, resulting in widespread water-rock interaction. Deeply understanding such effects is required to optimize the production system. In this study, the mechanisms of water-rock interaction and the associated responses of shale fabric are systematically reviewed for working fluids such as neutral fluids, acid fluids, alkali fluids and oxidative fluids. It is shown that shale is generally rich in water-sensitive components such as clay minerals,… More >

Abdul Sattar Laghari¹, Mohammad Waqas Chandio¹, Laveet Kumar^2,*, Mamdouh El Haj Assad³

Energy Engineering, Vol.121, No.8, pp. 2023-2038, 2024, DOI:10.32604/ee.2024.051082 - 19 July 2024

Abstract The selection of working fluid significantly impacts the geothermal ORC’s Efficiency. Using a mixture as a working fluid is a strategy to improve the output of geothermal ORC. In the current study, modelling and thermodynamic analysis of ORC, using geothermal as a heat source, is carried out at fixed operating conditions. The model is simulated in the Engineering Equation Solver (EES). An environment-friendly mixture of fluids, i.e., R245fa/R600a, with a suitable mole fraction, is used as the operating fluid. The mixture provided the most convenient results compared to the pure working fluid under fixed operating More >

Da Li, Guodong Zhang, Ke Sun^*, Shuzhan Bai, Guoxiang Li^*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.6, pp. 1479-1493, 2023, DOI:10.32604/fdmp.2023.022634 - 30 January 2023

Abstract A dedicated heat exchanger model is introduced for the optimization of heavy-duty diesel engines. The model is a prerequisite for the execution of CFD simulations, which are used to improve waste heat recovery in these systems. Several optimization methods coupled with different types of working fluids are compared in terms of exergy efficiency and heat exchanger complicity. The three considered optimization methods all lead to significant improvements in the R245fa and R1233zd systems with a comparatively low evaporation temperature. The optimal R245fa system has the highest efficiency increase (77.49%). The cyclopentane system displays the highest More >

Antonio Mariani, Davide Laiso, Biagio Morrone^*, Andrea Unich

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.3, pp. 593-601, 2023, DOI:10.32604/fdmp.2022.022524 - 29 September 2022

Abstract Waste heat recovery is one of the possible solutions to improve the efficiency of internal combustion engines. Instead of wasting the exhaust stream of an energy conversion system into the environment, its residual energy content can be usefully recovered, for example in Organic Rankine Cycles (ORC). This technology has been largely consolidated in stationary power plants but not yet for mobile applications, such as road transport, due to the limitations in the layout and to the constraints on the size and weight of the ORC system. An ORC system installed on the exhaust line of… More > Graphic Abstract

E. Flilihi^a,† , E. H. Sebbar^a, D. Achemlal^a, T. EL Rhafiki^a, M. Sriti^b, E. Chaabelasri^c

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-6, 2022, DOI:10.5098/hmt.18.39

Abstract In this paper, we made a numerical simulation of convective heat transfer in a rectangular section pipe of a air flat plate solar collector using three forms of the absorber plate namely, simple shape, rectangular-shape, and half circle-shape. The flow is considered laminar and stationary, where the heat exchange between the absorber plate and the fluid takes place in useful area. The computer code in fluid dynamics, the fluent, is applied to integrate the governing equations on each control volume. A detailed description of the fluid flow and heat transfer in the rectangular channel was More >

Roshan Devidas Bhagat^a,* , Samir J. Deshmukhsup>b

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-11, 2022, DOI:10.5098/hmt.19.14

Abstract Numerical analysis of liquid vapor slug flow in a vertically placed U-shaped closed capillary tube is carried out with family of hydrocarbon fluid like Acetone, Ethanol, Methanol and Pentane. A 3D computational domain has been developed for vertically placed U-shaped capillary tube sealed at both end with three small turns in evaporator section, two small and one large turn in condenser section. The diameter of vertically placed U-shaped capillary tube is taken as 2mm. The volume of fluid (VOF) approach, suitable model of K-epsilon is used to predict the behavior of liquid vapor slug flow… More >

Nugroho Agung Pambudi^1,*, Santiko Wibowo¹, Ranto¹, Lip Huat Saw²

Energy Engineering, Vol.118, No.5, pp. 1565-1576, 2021, DOI:10.32604/EE.2021.016642 - 16 July 2021

Abstract Organic Rankine Cycle (ORC) is one of the solutions to utilize a low temperature geothermal fluid for power generation. The ORC system can be placed at the exit of the separator to extract energy from brine. Furthermore, one of the main components of the system and very important is the pump. Therefore, in this research, the pump rotation is examined to investigate the effect on power output and energy efficiency for low temperature geothermal fluid. The rotation is determined by using an inverter with the following frequencies: 7.5, 10, 12.5, 15 and 17.5 Hz, respectively.… More >

Panpan Zhao^1,*, Dongdong Wang², Dao Zhou¹, Huan Zhang¹, Yun Sun¹

Energy Engineering, Vol.117, No.4, pp. 209-224, 2020, DOI:10.32604/EE.2020.010567 - 31 July 2020

Abstract A R1234ze(E) based mixture was investigated as a promising environmental solution to enhance system performance of a transctitical organic Rankine cycle(TORC). The main purpose of this study is to research the thermodynamic properties of TORC system using R1234ze(E)/R134a mixtures with various mass fraction of R1234ze(E) when recovering engine exhaust heat. R1234ze(E) was selected due to its zero ozone depletion potential, relative lower global warming potential and it can remedy the thermodynamic properties of traditional working fluid R134a. Thermal analysis and optimization about expander inlet temperature and pressure of TORC, mass fraction of R134a in R134a/R1234ze(E)… More >

Ziad Saghir, Cayley Delisle, Christopher Welsford^*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.1, pp. 19-19, 2019, DOI:10.32604/icces.2019.05145

Abstract The enhancement of consumer and industrial electronics has led to an increase in both the power and compactness of the products available. However, with these increases follows a subsequent increase in the thermal losses experienced across, for example, a central processing unit (CPU). As well, the need to dissipate waste thermal energy is compounded by the increased compactness. As the chipsets become smaller, the threads contained therein also reduce in size and as such become more sensitive to temperature gradients which can cause deformation. Although this deformation is miniscule, its continuous repetition can ultimately result… More >

A. Maouassi^a,b,*, A. Baghidja^a,b, S. Douad^c , N. Zeraibi^c

Frontiers in Heat and Mass Transfer, Vol.10, pp. 1-7, 2018, DOI:10.5098/hmt.10.35

Abstract This paper illustrates how practical application of nanofluids as working fluid to enhance solar flat plate collector efficiency. A numerical investigation of laminar convective heat transfer flow throw a solar collector is conducted, by using CuO-water nanofluids. The effectiveness of these nanofluids is compared to conventional working fluid (water), wherein Reynolds number and nanoparticle volume concentration in the ranges of 25– 900 and 0–10 % respectively. The effects of Reynolds number and nanoparticles concentration on the skin-friction and heat transfer coefficients are presented and discussed later in this paper. Results show that the heat transfer More >