Article
Thermodynamics
Jingyu Hao, Shuangshuang Meng, Zhihao He, Lin Zeng, Tianbiao He, Ning Mao
Summary: This paper investigates the effects of oil content, spray density, and spray temperature on the flow patterns and heat flux of a spray-type sewage heat exchanger in an oily sewage source heat pump system. The study reveals the need for higher spray density to maintain heat transfer in oily sewage compared to pure water, and proposes new heat transfer correlations that provide more accurate predictions.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Thermodynamics
Shuangshuang Meng, Zhihao He, Tianbiao He, Ning Mao
Summary: Recently, spray heat exchangers have gained significance in the recovery of heat energy from oily wastewater in sewage source heat pumps. Previous studies have emphasized the importance of tube bundle arrangement in falling film flow and heat transfer. This paper investigates the influence of oily content on bundle arrangement and analyzes the flow pattern and heat transfer effect using a numerical simulation. The results show significant differences in falling film flow and heat transfer coefficient between triangle and inline tube bundle arrangements, with the triangle arrangement showing higher heat transfer performance.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Zhu Zhang, Hao Lu
Summary: Researching the characteristics of fluid mechanism for heat transmission in falling film heat exchangers is crucial for oily wastewater treatment. In this study, numerical models were used to analyze the impact of factors such as liquid film flow rate and oil content on flow properties and heat transfer coefficient distribution. The results showed that increasing liquid film flow significantly affects velocity, the complex disturbance process of liquid film and the force change around tube structure plays a major role in how oil concentration affects heat transmission, inlet height has the greatest impact on local heat transfer coefficient at around 40 degrees, and hydrophobicity caused by increased contact angle deteriorates overall heat transmission.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2023)
Article
Green & Sustainable Science & Technology
Zhangxiang Wu, Shijun You, Tingting Jiang, Huan Zhang, Yaran Wang, Yan Jiang, Li Sha, Shen Wei
Summary: A novel air-source gas-fired absorption heat pump has been proposed for district heating, which is more efficient compared to traditional gas fired boilers. Through numerical analysis and experimental validation, the system was proven to be feasible and efficient for heating in cold regions under different operating conditions.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Energy & Fuels
Min-Hwi Kim, Deuk-Won Kim, Gwangwoo Han, Jaehyeok Heo, Dong-Won Lee
Summary: This study experimentally investigated the use of ground source heat pump (GSHP) and sewage water source heat pump (SWSHP) facilities in district cooling and heating networks, and derived a heat pump performance prediction model. It was found that fouling affects the cooling performance of SWSHP, and preventing fouling can lead to similar COP as GSHP.
Article
Thermodynamics
Chuang-Yao Zhao, Zhuo-Liang Yao, Di Qi, Wen-Tao Ji, An-Gui Li, Wen-Quan Tao
Summary: Falling film heat transfer is widely used in refrigeration and desalination systems. Numerical simulations show that bundle effect universally exists in falling film tube bundles and is influenced by liquid flow rate, distributor height, tube pitch, and tube bundle arrangement.
APPLIED THERMAL ENGINEERING
(2022)
Article
Mechanics
Yali Guo, Minle Bao, Luyuan Gong, Shengqiang Shen, Kun Zhang
Summary: In this study, numerical simulations were conducted to investigate the film thickness and heat transfer characteristics of a falling film evaporator over a horizontal round tube. The results showed that the film thickness had an asymmetric circumferential distribution, and the heat transfer coefficient reached its maximum value at the impact point. Increasing the spray density, saturation temperature, and longitudinal inter-tube spacing led to an increase in the film thickness and heat transfer coefficient.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Article
Thermodynamics
Na Qin, He Tian
Summary: A specially designed sewage source heat pump system was developed and tested, including a spiral-flow sewage filter and automatic backwashing plate sewage heat exchanger. The heat transfer coefficient model of the plate heat exchanger was validated, the impact of sewage flow velocity on the exchanger was analyzed, COP value was calculated, and energy conservation performance of the system was evaluated.
HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Zhihua Wan, Yanzhong Li, Sophie Wang
Summary: In this study, 2-D elliptical tube models based on the VOF method were established to investigate the effects of various parameters on falling film thickness and heat transfer coefficients. A mathematical algorithm combining RSM and MOGA was used to explore parameter sensitivity and optimization results. The results showed that Reynolds number, inlet temperature, and tube ellipticity positively impact heat transfer, while tube perimeter and seawater salinity have negative effects.
APPLIED THERMAL ENGINEERING
(2021)
Article
Green & Sustainable Science & Technology
Andrey Nikitin, Mahdi Deymi-Dashtebayaz, Sergei Muraveinikov, Veronika Nikitina, Reza Nazeri, Mehdi Farahnak
Summary: This paper compares the performance of air source and ground source cascade heat pumps using refrigerants with low global warming potential and zero ozone depletion potential in the top 10 coldest cities of Russia. The study investigates the effects of variations in temperature of the evaporator and cascade heat exchanger on the optimal operational conditions, through energy, exergy, economic, and environmental analysis using Pareto front curve. Findings indicate that Saint Petersburg is the best city for air source heat pump system, while ground source heat pump system is recommended for Khabarovsk city.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Thermodynamics
Qiang Wang, Xiaoming Zhang, Xinqi Geng, Xu Chen, Meize Xing
Summary: In this study, a sewage water source heat pump system was built for heat recovery from waste using a new type of sewage heat exchanger. The results showed that the heat transfer ability of the heat exchanger decreased slowly over time, and the system was able to produce hot water at a stable temperature. Energy analysis revealed that the continuous operation of the system could save significant amounts of energy.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Yunkai Yue, Junling Yang, Xiaoqiong Li, Yanchang Song, Yu Zhang, Zhentao Zhang
Summary: The study conducted a series of experiments on falling film flow and heat transfer characteristics outside the vertical tube, resulting in two new correlations that can provide reference for design of heaters in Mechanical vapor recompression systems.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Xueshuo Chen, Jiang Sheng, Tao Lu, Jie Wang, Kun Zhang, Xue Chen
Summary: Three-dimensional heat transfer during falling film evaporation was investigated numerically in this study. The results show that droplet flow, column flow, and sheet flow have different effects on the heat transfer coefficient. Dryout patches appear at lower spray densities and reduce the heat transfer until parts of the patches are rewet. The heat transfer coefficient for column flows is minimal at certain angles, while it varies only a small amount with the circumferential angle for sheet flows.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Yi Fan, Jing Li, Xudong Zhao, Steve Myers, Yuanda Cheng, Min Yu, Yousef Golizadeh Akhlaghi, Xiaoli Ma, Sen Yu
Summary: This study presents a proof-of-concept of a novel ventilation heat recovery vapor injection air source heat pump. The prototype demonstrates enhanced performance by significantly improving efficiency and reducing electricity consumption, with a fast and efficient defrosting process using exhaust air.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Energy & Fuels
Furqan Tahir, Sami G. Al-Ghamdi
Summary: Multi-effect desalination systems offer improved heat transfer and lower energy consumption, with the potential for increased water production and distillation efficiency through the use of new technologies.
Article
Thermodynamics
Ning Mao, Mengjie Song, Yingjie Xu
Summary: The study found that in sleeping state, human body heat balance is mainly affected by convective heat transfer and latent heat loss, with supply air temperature, flowrate, and humidity having different effects on heat loss.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Review
Energy & Fuels
Jibao Zhang, Shujun Chen, Ning Mao, Tianbiao He
Summary: The shortage of freshwater due to population growth and production improvement has led to an increasing need for novel technologies like hydrate-based desalination. This paper comprehensively analyzes literature on hydrate-based desalination, focusing on the impact of different hydrate formers on thermodynamics and dynamics. It also discusses hydrate crystal structure, molecular dynamic simulation, and energy consumption in the process. Ultimately, hydrated based desalination shows potential for sustainable fresh water production.
FRONTIERS IN ENERGY
(2022)
Review
Thermodynamics
Muhammad Abdul Qyyum, Amjad Khan, Sajid Ali, Muhammad Shahzad Khurram, Ning Mao, Ahmad Naquash, Adnan Aslam Noon, Tianbiao He, Moonyong Lee
Summary: This paper presents a state-of-the-art review on organic Rankine cycle (ORC) technology, examining the working fluids, thermal resources, cooling utilities, and commercial status. The study finds that mixed working fluids achieve higher thermodynamic efficiency, but their application is limited by difficulties in determining the optimal composition and components. Low-temperature ORC systems utilizing waste heat and geothermal energy are prevalent, while biomass and solar energy are underutilized as heat resources for ORC. The United States and Europe are leading in commercial applications of ORC for converting low-grade waste heat into useful power. The main challenges for ORC are selecting suitable working fluids and expanders, as well as reducing the specific cost of small-scale ORC systems to compete with renewable energy. Future research directions include investigating the overall performance, stability, and safety of ORC systems, developing a general methodology for selecting working fluids, and conducting techno-economic optimization studies to reduce costs. This study provides an overview of the recent progress in ORC technology and highlights the scientific problems that need to be addressed to harness low-grade heat for power generation in the future.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Energy & Fuels
Kinza Qadeer, Ashfaq Ahmad, Ahmad Naquash, Muhammad Abdul Qyyum, Khaliq Majeed, Zhongming Zhou, Tianbiao He, Abdul-Sattar Nizami, Moonyong Lee
Summary: This study utilized a cutting-edge neural network algorithm to optimize the SMR SNG liquefaction process, achieving energy savings of 16% to 2.4% by adjusting the MITA values. Economically, there were significant savings observed in the total capital investment and total annual cost, demonstrating the potential of cost-effective liquefaction technologies for clean and affordable energy production.
Article
Thermodynamics
Long Zhang, Mengjie Song, Ning Mao, Jiankai Dong
Summary: A novel frosting model was developed based on the frosting distribution characteristics of a tube-finned heat exchanger, and its temporal and spatial frost growth characteristics were numerically investigated. The results showed that the frost growth on the edge of windward fins had a significant impact on the entire frost growth of the heat exchanger.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Mechanics
Menglong Lu, Mengjie Song, Xiaoling Pang, Chaobin Dang, Long Zhang
Summary: A theoretical model for droplet freezing was developed and validated through experiments, showing good agreement. Gravity has a significant impact on freezing times, influenced by cold plate temperature, contact angle, and droplet volume. The study contributes to the optimization of refrigeration and defrosting technologies.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Review
Thermodynamics
Hongyu Lv, Huigang Ma, Ning Mao, Tianbiao He
Summary: This paper provides a comprehensive review of the boiling heat transfer characteristics of environmentally friendly refrigerants with low ODP and GWP, highlighting their importance in evaporator design and refrigeration cycle configuration. It also analyzes the effects of various factors on heat transfer coefficient and pressure drop, and offers insights into the mechanisms of heat transfer. Prospects and challenges for future research are identified, along with the recent progress made in this field.
INTERNATIONAL JOURNAL OF REFRIGERATION
(2022)
Article
Green & Sustainable Science & Technology
Hai Wang, Mengjie Song, Haoteng Li
Summary: This study aimed to optimize the fixed-focus solar concentrating system (FLSCS) and linear cavity receiver by studying the effects of receiver parameters on optical performance. The results showed that the sun declination angle had a weak effect on the optical efficiency loss, and the X-max mainly depended on the energy flux distribution. The changing trend of sigma(non) was consistent with that of the X-max.
Article
Thermodynamics
Mao Ning, Yu Hao, Zhuang Jiaojiao, Song Mengjie
Summary: This study investigated the influences of different supply air parameters on a personalized air conditioning system, and conducted numerical simulations. The results indicated that placing the supply air outlet at lower levels could improve the air change efficiency, but a higher supply air flow rate may cause draft risk.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Multidisciplinary Sciences
Libor Pekar, Mengjie Song, Subhransu Padhee, Petr Dostalek, Frantisek Zezulka
Summary: The focus of this contribution is to analyze the pole loci of a simple delayed model and apply it to parameter identification in a more complex heating-cooling process. The obtained results can provide accurate estimation of model parameters using dominant-pole-loci assignment and numerical optimization techniques.
SCIENTIFIC REPORTS
(2022)
Editorial Material
Energy & Fuels
Libor Pekar, Mengjie Song, Ning Mao, Hafiz Muhammad Ali, Wei Wu, Jie Cai
FRONTIERS IN ENERGY RESEARCH
(2022)
Article
Thermodynamics
Zuming Liu, Arijit Chakraborty, Tianbiao He, Iftekhar A. Karimi
Summary: The chemical industry relies heavily on fossil fuels, resulting in significant carbon emissions. Implementing combined heat and power (CHP) systems can effectively reduce both energy consumption and carbon emissions. This study presents a bi-objective optimization framework for CHP systems in chemical plants, considering steam turbine network design and renewable integration. The results demonstrate the trade-off between total annual cost and carbon emissions, showing the potential for emissions reduction through CHP systems.
APPLIED THERMAL ENGINEERING
(2023)
Review
Energy & Fuels
Hao Yu, Tongling Li, Xiaoxin Zeng, Tianbiao He, Ning Mao
Summary: This paper reviews, classifies, and summarizes the microchannel geometry characteristics of previous studies. It mainly focuses on the impact of microchannel geometry features and structural design on heat transfer and pressure drop, and discusses the future research direction of microchannel geometry design.
Article
Thermodynamics
Mahsa Taghavi, Swapnil Sharma, Vemuri Balakotaiah
Summary: This study investigates the natural convection effects in the insulation layers of spherical storage tanks and their impact on the tanks' performance. The permeability and Rayleigh number of the insulation material are considered as key factors. The results show that as the Rayleigh number increases, new convective cells emerge and cause the cold boundary to approach the external hot boundary. In the case of large temperature differences, multiple solutions may coexist.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyang Xu, Fangjun Hong, Chaoyang Zhang
Summary: This study introduces a self-induced jet impingement device for enhancing pool boiling performance in high power electronic cooling. Through visualization and parametric investigations, the effects of this device on pool boiling performance are studied, revealing the promotion of additional liquid supply and vapor exhausting. The flow rate of the liquid jet is found to positively impact boiling performance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Wenchao Ke, Yuan Liu, Fissha Biruke Teshome, Zhi Zeng
Summary: Underwater wet laser welding (UWLW) is a promising and labor-saving repair technique. A thermal multi-phase flow model was developed to study the heat transfer, fluid dynamics, and phase transitions during UWLW. The results show that UWLW creates a water keyhole, making the welding environment similar to in air laser welding.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Xingrong Lian, Lin Tian, Zengyao Li, Xinpeng Zhao
Summary: This study investigates the heat transfer mechanisms in natural fiber-derived porous structures and finds that thermal radiation has a significant impact on the thermal conductivity in low-density regions, while natural convection rarely occurs. Insulation materials derived from micron-sized natural fibers can achieve minimum thermal conductivity at specific densities. Strategies to lower the thermal conductivity include increasing porosity and incorporating nanoscale pores using nanosize fibers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Yasir A. Malik, Kilian Koebschall, Stephan Bansmer, Cameron Tropea, Jeanette Hussong, Philippe Villedieu
Summary: Ice crystal icing is a significant hazard in aviation, and accurate modeling of sticking efficiency is essential. In this study, icing wind tunnel experiments were conducted to quantify the volumetric liquid water fraction, sticking efficiency, and maximum thickness of ice layers. Two measurement techniques, calorimetry and capacitive measurements, were used to measure the liquid water content and distribution in the ice layers. The experiments showed that increasing wet bulb temperatures and substrate heat flux significantly increased sticking efficiency and maximum ice layer thickness.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinqi Hu, Tongtong Geng, Kun Wang, Yuanhong Fan, Chunhua Min, Hsien Chin Su
Summary: This study experimentally examined the heat dissipation of vibrating fans and demonstrated its inherent mechanism through numerical simulation. The results showed that the flow fields induced by the vibrating blades exhibited pulsating features and formed large-scale and small-scale vortical structures, significantly improving heat dissipation. The study also identified the impacts of different blade structures and developed a trapezoidal-folding blade, which effectively reduced the maximum temperature of the heat source and alleviated high-temperature failure crisis.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Dan-Dan Su, Xiao-Bin Li, Hong-Na Zhang, Feng-Chen Li
Summary: The boiling heat transfer of low-boiling-point working fluid is a common heat dissipation technology in electronic equipment cooling. This study analyzed the interfacial boiling behavior of R134a under different conditions and found that factors such as the initial thickness of the liquid film, solid-liquid interaction force, and initial temperature significantly affect the boiling mode and thermal resistance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Jinyi Wu, Dongke Sun, Wei Chen, Zhenhua Chai
Summary: A unified lattice Boltzmann-phase field scheme is proposed to simulate dendrite growth of binary alloys in the presence of melt convection. The effects of various factors on the growth are investigated numerically, and the model is validated through comparisons and examinations.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shaokun Ge, Ya Ni, Fubao Zhou, Wangzhaonan Shen, Jia Li, Fengqi Guo, Bobo Shi
Summary: This study investigated the temperature distribution of main cables in a suspension bridge during fire scenarios and proposed a prediction model for the maximum temperature of cables in different lane fires. The results showed that vehicle fires in the emergency lane posed a greater thermal threat to the cables.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shuang-Ying Wu, Shi-Yao Zhou, Lan Xiao, Jia Luo
Summary: This paper investigates the two-phase flow and heat transfer characteristics of low-velocity jet impacting on a cylindrical surface. The study reveals that the heat transfer regimes are non-phase transition and nucleate boiling with the increase of heat transfer rate. The effects of jet impact height and outlet velocity on local surface temperatures are pronounced at the non-phase transition stage. The growth rates of heat transfer rate and liquid loss rate increase significantly from the non-phase transition to nucleate boiling stage.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Emad Hasani Malekshah, Wlodzimierz Wlodzimierz, Miros law Majkut
Summary: Cavitation has significant practical importance and can be controlled by air injection. This study investigates the natural to ventilated cavitation process around a hydrofoil through numerical and experimental methods. The results show that the location and rate of air injection have a meaningful impact on the characteristics of cavitation.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Feriel Yahiat, Pascale Bouvier, Antoine Beauvillier, Serge Russeil, Christophe Andre, Daniel Bougeard
Summary: This study explores the enhancement of mixing performance in laminar flow equipment by investigating the generation of chaotic advection using wall deformations in annular geometries. The findings demonstrate that the combined geometry can achieve perfect mixing at various Reynolds numbers.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Hui He, Ning Lyu, Caihua Liang, Feng Wang, Xiaosong Zhang
Summary: This study investigates the condensation, frosting, and defrosting processes on superhydrophobic surfaces with millimeter-scale structures. The results reveal that the structures can influence the growth and removal of frost crystals, with the bottom grooves creating a frost-free zone and conical edges promoting higher frost crystal heights. Two effective methods for defrosting are observed: hand-lifting the groove and airfoil retraction contraction on protruding structures. This research provides valuable insights into frost formation and defrosting on millimeter-structured superhydrophobic surfaces, with potential applications in anti-frost engineering.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Thiwanka Arepolage, Christophe Verdy, Thibaut Sylvestre, Aymeric Leray, Sebastien Euphrasie
Summary: This study developed two thermal concentrators, one with a 2D design of uniform thickness and another with a 3D design, using the coordinate transformation technique and metamaterials. By structuring the thermal conductor, the desired local density-heat capacity product and anisotropic thermal conductivities were achieved. The homogenized thermal conductivities were obtained from finite element simulations and cylindrical symmetry consideration. A 3D concentrator was fabricated using 3D metal printing and characterized using a thermal camera. Compared to devices that solely consider anisotropic conductivities, the time evolution characteristics of the metadevice designed with coordinate transformation were closer to those of an ideal concentrator.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Liangyuan Cheng, Qingyang Wang, Jinliang Xu
Summary: In this study, we investigated the supercritical heat transfer of CO2 in a horizontal tube with a diameter of 10.0 mm, covering a wide range of pressures, mass fluxes, and heat fluxes. The study revealed a non-monotonic increase in wall temperatures along the flow direction and observed both positive and negative wall temperature differences between the bottom and top tube. The findings were explained by the thermal conduction in the solid wall interacting with the stratified-wavy flow in the tube.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
