Yun Hao^* , Shaohua Lv, Song Wu

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-8, 2022, DOI:10.5098/hmt.18.3

Abstract Traditional methods of enhancing the thermal efficiency of heating furnaces in continuously producing oilfields, such as replacing existing units with more efficient units or renovating old furnaces, are highly inconvenient. This paper studied on the characteristics of nanofluids, a novel heat transfer medium with excellent heat transfer characteristics to enhance the thermal efficiency of heating furnaces. The stable nanofluids (Al₂O₃-H₂O, SiO₂- H₂O, and TiO₂-H₂O) were prepared by a two-step method and various chemical and physical treatments were carried out. Thermal conductivities of the nanofluids were measured using the transient hot-wire method. Based on the analysis, the most appropriate nanofluid (TiO₂-H₂O)… More >

Amnart Boonloi^a, Withada Jedsadaratanachai^b,*

Frontiers in Heat and Mass Transfer, Vol.18, pp. 1-13, 2022, DOI:10.5098/hmt.18.2

Abstract This study numerically investigates pressure loss, heat transfer and thermal efficiency in round tube heat exchangers attached with various types of Vrings. A typical type A V-ring is compared with two types of modified V-rings (type B and C). The impacts of blockage ratios, b/D = 0.05, 0.10, 0.15 and 0.20 for all V-ring types in the turbulent region are discussed (Re = 3000 – 20,000). Flow directions in the round pipe attached with the V-rings are varied. The V-apex setting downstream is referred to as “V-Downstream, while the V-apex setting upstream is referred to as “V-Upstream”. The flow and… More >

Rajen Kumar Nayak^a,* , Ravi Shankar Prasad^a,† , Ujjwal Kumar Nayak^a, Amit Kumar Gupta^b

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-12, 2022, DOI:10.5098/hmt.19.22

Abstract The present experimental work has been carried out for a solar air heater under cross flow condition having inline hole jet plate between bottom plate and absorber plate with longitudinal fins underside the absorber surface. The performance of this inline hole jet plate solar air heater is compared with the performance of jet plate solar air heaters without longitudinal fins under cross and non-cross flow conditions for similar geometrical and operational parameters. Results are presented for mass flow rates of air, ṁ₁ = 0.020 - 0.070 kg/sec, ṁ₂ = 0.018 - 0.041 kg/sec, flow Reynolds number, Re_ja2 = 2000 -… 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 >

Erdiwansyah Erdiwansyah^a,e,f, Mahidin Mahidin^b,*, Husni Husin^b, Nasaruddin Nasaruddin^c, Asri Gani^b, Muhammad Faisal, Muhtadin Muhtadin^d, Muhammad Zaki^b, Rizalman Mamat^e

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-9, 2023, DOI:10.5098/hmt.20.29

Abstract The conversion of solid biomass waste into energy continues to be developed at this time to reduce dependence on fossil energy. Energy conversion can be carried out using several technologies commercialized by several industries, including the fluidized-bed combustor (FBC). This FBC technology has also been developed in several ways, such as the modification or unique modelling. In particular, the perforated plate modelling applied in this study is to provide excess air supply so that complete combustion can be achieved. In addition, modifying the perforated plate increases efficiency and radiation and reduces heat loss in the FBC combustion chamber. This research… More >

Yangyang Tian^a , Zhuo Chen^b,* , Qi Zhuang^c

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-11, 2023, DOI:10.5098/hmt.20.26

Abstract The cyclone separator has remarkable amplification effect, which is an important factor affecting its separation efficiency and pressure drop. The numerical simulation of Stairmand cyclone separators with cylinder diameters of 200, 280, 400, 480 and 600mm after geometric similarity amplification was carried out by ANSYS software. RSM model was used for gas phase and DPM model was used for particle phase. The results show that after the cyclone size is enlarged geometrically, the tangential velocity tends to increase with the increase of the cyclone barrel diameter at the same inlet gas velocity, which leads to the increase of turbulence energy… 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 >

Mohammed Basheri, Mahmoud Ragab^*

Computer Systems Science and Engineering, Vol.46, No.3, pp. 3783-3798, 2023, DOI:10.32604/csse.2023.037130

Abstract The Internet of Things (IoT) is one of the emergent technologies with advanced developments in several applications like creating smart environments, enabling Industry 4.0, etc. As IoT devices operate via an inbuilt and limited power supply, the effective utilization of available energy plays a vital role in designing the IoT environment. At the same time, the communication of IoT devices in wireless mediums poses security as a challenging issue. Recently, intrusion detection systems (IDS) have paved the way to detect the presence of intrusions in the IoT environment. With this motivation, this article introduces a novel Quantum Cat Swarm Optimization… More >

Sheng Xiao^1,*, Yong Chen², Jing He³, Xi Yang⁴

Computer Systems Science and Engineering, Vol.46, No.3, pp. 3527-3540, 2023, DOI:10.32604/csse.2023.027081

Abstract Read-write dependency is an important factor restricting software efficiency. Timing Speculative (TS) is a processing architecture aiming to improve energy efficiency of microprocessors. Timing error rate, influenced by the read-write dependency, bottlenecks the voltage down-scaling and so the energy efficiency of TS processors. We proposed a method called Read-Write Dependency Aware Register Allocation. It is based on the Read-Write Dependency aware Interference Graph (RWDIG) conception. Registers are reallocated to loosen the read-write dependencies, so resulting in a reduction of timing errors. The traditional no operation (Nop) padding method is also redesigned to increase the distance value to above 2. We… More >