Hussein Al-Gburi^*, Akeel Abbas Mohammed, Audai Hussein Al-Abbas

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-7, 2023, DOI:10.5098/hmt.20.17

Abstract Transferring thermal energy efficiently necessitates utilizing a heat exchanger capable of producing the full thermal power of the energy supply at lowest possible cost and time. Therefore, in the present investigation, the impact of corrugated helical coil concentric tube-in-tube heat exchanger on the thermal performance is investigated experimentally. As a continuous in our issue of heat exchanger, the corrugated helical tube-in-tube is carried out and compared with smooth helical tube-in-tube for free convection heat transfer. The set-up of the experimental apparatus are designed and utilized to be appropriate for the cooling and heating systems of working fluid. The impacts of… More >

O. M. Oyewola^a,b,* , M. O. Petinrin^a , and H. O. Sanusi^a

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-8, 2023, DOI:10.5098/hmt.20.16

Abstract The flow and heat transfer behaviour of channels with dimples and protrusions of spherical and piriform shapes was numerically explored by solving the Navier-Stokes and energy equations with a CFD software, the ANSYS Fluent 19.3, in the range of Reynolds numbers from 8,500 to 59,000. The values of the Nusselt number and friction factors were estimated and the non-dimensional Performance Evaluation Criterion (PEC) was determined to measure the thermal-hydraulic performance. The results reveal that the piriform protruded channel demonstrated a higher thermal performance with Nusselt number values of 36%, 15%, 23%, and 9% than the smooth, spherical dimpled, piriform dimpled,… More >

Wenhua Liu^a,b, Mo Yang^c,a,*, Yuwen Zhang^b , Guiliang Liu^a , Liang Ling^a , Xuchen Ying^a,*

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-7, 2023, DOI:10.5098/hmt.20.15

Abstract In this study, numerical investigations are performed on a partially premixed flame of methane and air in two- and three-dimensional models. Nonlinear method is adopted to illustrate the asymmetric phenomenon that affects the flame stability under various co-flow velocities. According to the results, the mathematical relationship between the flame flickering frequency Stanton number and the dimensionless velocity Froude number has been summarized as St=0.7Fr^-0.46. The bifurcation phenomena under different Reynold numbers are found to have significant influence on the system stability. Two critical bifurcation points, which is when Re=300 and Re=1200, are determined as the onset of breaking the flame… More >

Linfang Fang, Fuyong Su^* , Zhen Kang, Haojun Zhu

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-9, 2023, DOI:10.5098/hmt.20.14

Abstract Taking the ladle used by a factory as an example, a three-dimensional finite element model of the ladle was established, and the temperature distribution law of the lining during the ladle transportation was studied using the finite element analysis software ANSYS, which verified the good thermal insulation performance of the nano thermal insulation layer, and analyzed and compared the temperature and distribution law of the refractory lining under the two working conditions of the heavy ladle and the empty ladle. The results show that due to the change of the boundary conditions in the empty ladle state, the temperature change… More >

Qi Zhuang^a,* , Dong Liu^b, Bo Liu^c, Mei Liu^a

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-6, 2023, DOI:10.5098/hmt.20.13

Abstract In the actual operation of wet gas pipeline, liquid accumulation is easy to form in the low-lying and uphill sections of the pipeline, which leads to a series of problems such as reduced pipeline transportation efficiency, increased pipeline pressure drop, hydrate formation, slug flow and intensified corrosion in the pipeline. Accurate calculation of liquid holdup is of great significance to the research of flow pattern identification, pipeline corrosion evaluation and prediction, and gas pipeline transportation efficiency calculation. Based on the experimental data of liquid holdup in horizontal pipeline, a commonly used BP neural network (BPNN) model is established in this… More >

Tieming Wang^a , Fuyong Su^b,*

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-4, 2023, DOI:10.5098/hmt.20.12

Abstract This paper analyzes the power generation technology of coke dry quenching (CDQ) waste heat boiler, and compares the exergy efficiency of medium temperature medium pressure boiler and high temperature high pressure boiler. The scheme of high temperature ultrahigh pressure primary intermediate reheat boiler to further improve the power generation efficiency of CDQ waste heat is put forward, and the exergy efficiency is analyzed. The bottleneck problem of further improving power generation efficiency by CDQ waste heat power generation and the exergy efficiency limit under the current process conditions are obtained. More >

Yu-Liang Zhang^a,* , Dong-Yang Wu^b, Hai-Bing Cai^c, Can-Fei Wang^c, Fei-Wu^c, Shao-Han Zheng^d

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-5, 2023, DOI:10.5098/hmt.20.11

Abstract In this paper, based on the Mixture model, the numerical computations of the internal flow field in a sewage pump are carried out. Through numerical simulation, the turbulence flow characteristics in the sewage pump are obtained. Results show that when the particle diameter is 0.10 mm, the solid-phase concentration on the volute surface is high, and the wear is more severe. When the particle diameters are 0.15 mm and 0.20 mm, the solid-phase concentration on the volute surface is significantly higher, especially when the over-current cross-section enlarges constantly. More >

L.H. Tong^a , Y.L. Zhang^b,†, T.H. Yu^a, B.Y. Luo^c, J.F. Li^b

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-8, 2023, DOI:10.5098/hmt.20.10

Abstract In order to explore the thermal characteristics of a small nozzle flowmeter in the solid domain when transporting medium with different temperatures, the steady and transient thermal characteristics of each component of the nozzle flowmeter are calculated based on the finite element method. Results showed that the numerical calculation method could effectively reveal the internal thermal characteristics. When transporting high temperature medium, there was an obvious temperature stratification near the inner wall; when the inner wall temperature rose from 50 °C to 700 °C, the heat flow field at the inlet and outlet of the flowmeter increased significantly with the… More >

Mirmanto Mirmanto^a,*, Syahrul Syahrul^a, Agung Tri Wijayanta^b

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-5, 2023, DOI:10.5098/hmt.20.9

Abstract A study to examine the effect of evaporator diameters on the performances of a custom air-water generator had been conducted in naturally room air temperatures. Performances in this study consisted of fresh water production, coefficient of performance, and total heat transfer from the air. The freshwater was attained from the dew that dropped from the evaporator walls. It was from water vapour in the air that condensed due to the low temperature of the evaporator walls. The evaporator which had dimensions of 285 mm x 12.7 mm x 480 mm was placed in an open box (top and bottom). It… More >

M. El-Bayoumi^a,†, A. M. Abouel-Fotouh^a, Amal El Berry^a

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-6, 2023, DOI:10.5098/hmt.20.8

Abstract Ram pumps employ renewable energy in the form of water head to pump water, but they have performance issues that require difficult on-site testing and tuning, hence limiting their application. The current research developed a low-cost lab-scale testing system for small ram pumps’ performance evaluation, tuning and leak testing. The developed system is made from available, low-cost, sensors and components. It conserves test water by setting the supply head through continuous circulation of water. The system was tested on a low-cost small sized ram pump, specially built using plumbing components. Test results demonstrated the capacity of the developed testing system. More >