Huashan Li¹, Xiaoshuang Zhao^1,2, Sihao Huang^1,2, Lingbao Wang¹, Jiongcong Chen^1,*

Energy Engineering, Vol.120, No.8, pp. 1817-1835, 2023, DOI:10.32604/ee.2023.027668 - 05 June 2023

Abstract Process heating constitutes a significant share of final energy consumption in the industrial sector around the world. In this paper, a high-temperature heat pump (HTHP) using flash tank vapor injection technology (FTVI) is proposed to develop low-temperature geothermal source for industrial process heating with temperature above 100°C. With heat sink output temperatures between 120°C and 150°C, the thermo-economic performance of the FTVI HTHP system using R1234ze(Z) as refrigerant is analyzed and also compared to the single-stage vapor compression (SSVC) system by employing the developed mathematical model. The coefficient of performance (COP), exergy efficiency (η_exe), net present… More >

Yuqin Wang^1,2,3,*, Luxiang Zhou³, Mengle Han¹, Lixiang Shen¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.9, pp. 2215-2228, 2023, DOI:10.32604/fdmp.2023.027188 - 16 May 2023

Abstract The main structural parameters of the IR100-80-100A type chemical centrifugal pump have been optimized by means of an orthogonal test approach. The centrifugal pump has been modeled using the CFturbo software, and 16 sets of orthogonal-test schemes have been defined on the basis of 4 parameters, namely, the blade number, blade outlet angle, impeller outlet diameter, and impeller outlet width. Such analysis has been used to determine the influence of each index parameter on the pump working efficiency and identify a set of optimal combinations of such parameters. The internal flow field in the centrifugal More > Graphic Abstract

Le Anh Duc^a , Pham Van Kien^b,*, Nguyen Thanh Tan^b, Doan Thanh Son^b, Nhanh Van Nguyen^c, Ngoc Xuan Nguyen^d

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-6, 2023, DOI:10.5098/hmt.20.25

Abstract This study focused on the heat and mass transfer in radio (RF) assisted heat pump (HP) drying of carrots. The experimental drying of carrot by RF assisted HP drying method was conducted to evaluate the effect of RF power on drying efficiency including drying rate and heating rate. The input drying parameters were drying air temperature of 45oC, drying air velocity of 2.5 m/s and RF power of 0, 0.5 and 1.5 kW, in which, RF power of 0 was corresponding to HP drying method. The experimental drying results showed that in RF assisted HP… More >

Feng-Lin Zhou^a , Kai-Yuan Zhang ^a, Liang Cheng^b,† , Hai-Bing Cai^c, Yu-Liang Zhang^b, Min-Feng Lv^d

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-10, 2023, DOI:10.5098/hmt.20.22

Abstract In order to grasp the reverse startup characteristics of a small radial vane pump in the case of misoperation, a circulation piping system that includes the pump is established. Numerical simulation of the full three-dimensional unsteady incompressible viscous flow is performed based on the slip-grid technique and user-defined functions (UDF). According to the results, the static pressure fluctuation is small at the inlet of the centrifugal pump during the reverse startup, which differs significantly from the forward startup. Compared to the impeller rotational speed, the time required for the shaft power, head and flow curves… 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 >

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 More >

Siwei Han^1,*, Xianglong Li², Wei Zhao¹, Linyu Wang¹, Anqi Liang², Shuang Zeng²

Energy Engineering, Vol.120, No.6, pp. 1421-1444, 2023, DOI:10.32604/ee.2023.027094 - 03 April 2023

Abstract Photovoltaics, energy storage, direct current and flexibility (PEDF) are important pillars of achievement on the path to manufacturing nearly zero energy buildings (NZEBs). HVAC systems, which are an important part of public buildings, play a key role in adapting to PDEF systems. This research studied the basic principles and operational control strategies of a DC inverter heat pump using a DC distribution network with the aim of contributing to the development and application of small DC distribution systems. Along with the characteristics of a DC distribution network and different operating conditions, a DC inverter heat… More >

Qunbiao Wu¹, Zhen Wang^1,*, Haifeng Fang¹, Junji Chen¹, Xinfeng Wan²

Computer Systems Science and Engineering, Vol.46, No.1, pp. 961-979, 2023, DOI:10.32604/csse.2023.036239 - 20 January 2023

Abstract For surface defects in electronic water pump shells, the manual detection efficiency is low, prone to misdetection and leak detection, and encounters problems, such as uncertainty. To improve the speed and accuracy of surface defect detection, a lightweight detection method based on an improved YOLOv5s method is proposed to replace the traditional manual detection methods. In this method, the MobileNetV3 module replaces the backbone network of YOLOv5s, depth-separable convolution is introduced, the parameters and calculations are reduced, and CIoU_Loss is used as the loss function of the boundary box regression to improve its detection accuracy.… More >

Wenbin Luo^1,*, Lingfeng Tang¹, Yuting Yan², Yifang Shi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.4, pp. 869-899, 2023, DOI:10.32604/fdmp.2022.022280 - 02 November 2022

Abstract The aim of the study is to determine the optimal structural parameters for a plastic centrifugal pump inducer within the framework of an orthogonal experimental method. For this purpose, a numerical study of the related flow field is performed using CFX. The shaft power and the head of the pump are taken as the evaluation indicators. Accordingly, the examined variables are the thickness (S), the blade cascade degree (t), the blade rim angle (β1), the blade hub angle (β2) and the hub length (L). The impact of each structural parameter on each evaluation index is More >

Surendrababu Kuppusamy^1,*, Prabhahar Muthuswamy², Muthurajan Kumarasamy³, Sendilvelan Subramanian⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.4, pp. 1003-1014, 2023, DOI:10.32604/fdmp.2022.022262 - 02 November 2022

Abstract Biodiesel fuel is a potential alternative energy source for diesel engines due to its physiochemical characteristics relatively similar to those of traditional diesel fuel. In this study, the performance, emission, and combustion features of a mono cylinder DI diesel engine are assessed using 20% Pumpkin seed methyl ester (PSOME20) and considering varying injection pressures (200, 220, 240, and 260 bar). The considered Pumpkin seed oil is converted into pumpkin biodiesel by transesterification and then used as fuel. The findings demonstrate that the Brake Thermal Efficiency (BTE) of PSOME20 can be raised by 1.68%, and the More > Graphic Abstract