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Measurement of thermal deviation of flue-gas in crossover pass of single tangential boiler

APPLIED THERMAL engineering 2021年 188卷 116647-116647页

作者： Ping, Li Xie, Jianwen Yang, Bin Wen, Wubin Wang, Ying Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China Shenhua Guohua Beijing Elect Power Res Inst Co Lt Beijing 100025 Peoples R China Jiangsu Guohua Chenjiagang Power Generat Co Ltd Yancheng 224631 Jiangsu Peoples R China

Aiming at the problem of thermal deviation in crossover pass of single tangential boiler, an on-line measurement method of radiation parameters of high temperature coal particles based on radiation spectroscopy was proposed. A measurement system consisting of an optical fiber spectrometer system and a water-cooled structure probe was developed, which was used to measure the radiation parameters of high temperature coal particles in crossover pass of the boiler. The radiation spectra at 500-1000 nm band on the gas flow side of the final reheaters inlet section of a 660 MW ultra-supercritical boiler were measured by the system. According to Planck's law, the distribution of coal particles temperature, emissivity and other parameters along the section was obtained by fitting parameter method. The results show that the burnout delay of pulverized coal particles caused by the airstage combustion system and the radiant heat transfer deviation caused by the non-uniform concentration of coal particles are the main causes of the thermal deviation of the final reheaters. Under the condition of increasing yaw angle of SOFA nozzles, the ability of SOFA to alleviate the residual swirling flow is significant, and the temperature distribution of coal particles in the crossover pass is more uniform. However, due to the phenomenon of single-side particles accumulation still exists, the deviation of particles radiation intensity remains large, which cannot effectively reduce the steam temperature deviation in reheaters. Through differentially adjusting the angles of SOFA nozzles in vertical direction and horizontal direction, the phenomenon of single-side coal particles accumulation can be improved, the non-uniform radiation heat transfer of heat exchangers on both sides can be balanced, and the steam temperature deviation in final reheaters can be reduced.

关键词： Single tangential boiler Thermal deviation On-line measurement Radiation spectroscopy Coal particles

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Investigation on reverse cycle defrosting strategy of an outdoor heat exchanger in air conditioning heat pump system for electric vehicles

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CASE STUDIES IN THERMAL engineering 2021年 27卷

作者： Li, Kang Xia, Dingyu Bao, Jiaqian Luo, Shuxian Zhang, Hua Liu, Ni Su, Lin Sheng, Lei Univ Shanghai Sci & Technol Sch Energy & Power Engn 516 Jungong Rd Shanghai 200093 Peoples R China Univ Shanghai Sci & Technol Key Lab Multiphase Flow & Heat Transfer Shanghai Shanghai 200093 Peoples R China Univ Shanghai Sci & Technol Sch Mech Engn Shanghai 200093 Peoples R China

Outdoor heat exchanger in air conditioning heat pump (ACHP) system would frost quickly under a low-temperature but high-humidity surroundings. System performance and efficiency would significantly decrease without a rapid and appropriate defrosting strategy. In this work, a quick response reverse cycle defrosting strategy for an ACHP system in electric vehicles is presented, and its effectiveness is validated experimentally. Frosting experiments were conducted to capture the typical heat transfer parameters and frosting behaviors, and then the frost coverage ratio was obtained with threshold division method. An uneven frosting process were observed on the surface of the microchannel outdoor heat exchanger due to uneven dryness distribution. Then a certain frost coverage ratio was obtained as the reverse start criteria, and a series of defrosting experiment were conducted in validation of the reserve defrosting strategy. Results show that the frost coverage ratio of 0.56, or 2 degrees C deterioration of indoor outlet air temperature can be chosen as the reverse start criterion value with the current reverse cycle defrosting strategy for vehicular ACHP system. Frost can be almost removed completely within 40s with the proposed reverse defrosting strategy under the condition of ambient temperature 0-5 degrees C and relative humidity 80-85%.

关键词： Vehicular air conditioning heat pump system Outdoor heat exchanger Reverse cycle defrosting Threshold division method Frost coverage ratio

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Investigation of transient coupled conduction and radiation heat transfer in the linearly anisotropic scattering cylindrical medium by spectral collocation method

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INTERNATIONAL JOURNAL OF THERMAL SCIENCES 2022年第PartA期172卷 107308-107308页

作者： Sun, Yasong Li, Xinyu Zhao, Jiazi Hu, Yang Jing, Xin Ma, Jing Zhou, Ruirui Northwestern Polytech Univ Basic Res Ctr Sch Power & Energy Xian 710064 Peoples R China Northwestern Polytech Univ Ctr Computat Phys & Energy Sci Yangtze River Delta Res Inst NPU Taicang 215400 Jiangsu Peoples R China Changan Univ Sch Automobile Key Lab Shaanxi Prov Dev & Applicat New Transport Xian 710064 Peoples R China Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China

In this paper, a spectral collocation method (SCM) is developed to solve transient conduction and radiation heat transfer problems in infinitely long annular cylinders with participating medium. The participating medium is an absorbing, emitting and linearly anisotropic scattering medium. To avoid the complex calculation of ray tracing, the radiative transfer equation and the transient heat conduction equation are expressed in eulerian coordinates. In the solving process, for the radiative transfer equation, both spatial and angular domains are discretized by the SCM;for the transient heat conduction equation, the spatial domain is discretized by the SCM, and the time domain is discretized by the fully implicit Euler scheme. The spatial derivative term, angular derivative term and scattering source integral term are approximated by the high order spectral collocation scheme. Compared with available data in references, the SCM can achieve very good accuracy even using few nodes. Thus, the SCM is a very effective method to achieve high order accuracy for transient coupled conduction and radiation heat transfer in an anisotropic scattering cylindrical medium. Moreover, the effects of conduction-radiation parameter, optical thickness, and wall emissivity on the transient temperature distribution and energy flow rate have also been comprehensively investigated.

关键词： Transient conduction-radiation Spectral collocation method Cylindrical enclosure Anisotropic scattering

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Revealing bulk reaction kinetics of battery-like electrode for pseudocapacitor with ultra-high rate performance

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CHEMICAL engineering JOURNAL 2022年第Part2期450卷

作者： Yin, Baoyi Hao, Liang Wei, Tao Wang, Chen Zhu, Bao Li, Xiaogan Yang, Qiguo Dalian Univ Technol Sch Microelect Dalian 116024 Peoples R China Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China Univ Jinan Sch Mat Sci & Engn 336 Nanxinzhuang West Rd Jinan 250022 Shandong Peoples R China Fudan Univ Sch Microelect State Key Lab ASIC & Syst Shanghai 200433 Peoples R China Natl Integrated Circuit Innovat Ctr Shanghai 201203 Peoples R China

Battery-like electrode materials have a high theoretical capacity but suffer from low electrical conductivity and poor structural stability, which are expected to be solved by revealing bulk reaction kinetics of crystal structure to improve the electrochemical performance. Herein, we grow NiCo-LDH single-crystal nanowires along the [003] crystal plane on the surface of amorphous SiO2 hollow spheres. This heterostructured architecture provides a synergistic effect among different components and enlarges the interlayer spacing of the grown NiCo-LDH single-crystal, offering more reactive sites and improving electrical conductivity. The prepared NiCo-LDH@SiO2/C electrode demonstrates ultra-high rate capability with 78.1 % capacitance retention even after a 40-fold increase in the current density. The asymmetric supercapacitors with NiCo-LDH@SiO2/C cathode and active carbon anode could deliver a maximum energy density of 47.6 Wh/g at 1383 W/kg. This work presents a new method to guide the design of NiCo-LDH electrode materials and opens up a new opportunity to develop high-performance battery-type electrode materials for pseudocapacitors.

关键词： Battery-like electrode Enhanced conductivity Controllable interlayer space Ultra-high rate

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A side-scattering imaging method for the in-line monitoring of particulate matter emissions from cooking fumes

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MEASUREMENT SCIENCE AND TECHNOLOGY 2021年第3期32卷

作者： Zhou, Wu Mei, Cong Qin, Jinwei Cai, Xiaoshu Wang, Tianyi He, Wanqing Shi, Aijun Univ Shanghai Sci & Technol Sch Energy & Power Engn Jungong Rd 516 Shanghai 200093 Peoples R China Shanghai Key Lab Multiphase Flow & Heat Transfer Jungong Rd 516 Shanghai 200093 Peoples R China Beijing Municipal Res Inst Environm Protect Beijing 100037 Peoples R China

To monitor the concentration of particulate matter (PM) from cooking fumes, an in-line measurement method was proposed based on the Lorenz-Mie scattering theory, and a measurement system was developed based on the side-scattering imaging technique with a laser beam for illumination. Polystyrene particles in water suspensions with a known particle size and concentration were utilized for validation. The experimentally obtained gray level of the image of the particle cloud along the laser beam agrees well with that predicted by theoretical model in the same configuration. The artificial fish swarm algorithm was adopted for inversion, and the results of particle size measurements show a standard deviation lower than 5% of the mean measured value at concentrations of 0.5-50 mg center dot m(-3). Using the retrieved particle size distribution, the PM concentrations can be measured with the calculated scattering coefficient k(2) and the measurement system dependent coefficients I(0)k(1). The calibration experiments with polystyrene particle suspensions show a very good linear relationship of the image gray value on the particle concentration. This method makes it possible to monitor the PM concentrations using a non-contact and non-suction approach.

关键词： side-scattering imaging cooking fumes particulate matter emission size concentration

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Experimental study on aerodynamic performance of deformable blade for vertical axis wind turbine

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ENERGY 2019年 181卷 187-201页

作者： Wang, Ying Tong, Hui Sima, Hao Wang, Jiayue Sun, Jinjing Huang, Diangui Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai 200093 Peoples R China Univ Shanghai Sci & Technol Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China

In this paper, a new type of blade model driven by single input for vertical axis wind turbine was developed, and it could achieve synchronous active deformation for both of blade leading edge and trailing edge. Firstly, by taking the concept of ribs and by taking NACA0012 airfoil as an example, the mechanical structure and skin with adhesion mechanism of pre-tightening force was adopted based on the continuous deflection and deformation mode of the blade leading and trailing edges with constant thickness. In this way, the adaptive blade could achieve reciprocating smooth deformation with different cambers. Secondly, the experimental platform for measurement of wind tunnel force and flow visualization was built up, where the smoke wire instrument, seven-hole probe, two-component balance were applied for measuring of quasi steady force and flow visualization under different deformation quantities. Finally, the aerodynamic performance of adaptive blade under different deformation factors was revealed. It is found that within an appropriate range of deformation factor, the blade aerodynamic performance can be improved by deforming. When exceeding the critical camber, the friction resistance becomes a dominant factor effecting blade aerodynamic performance. In all, the experimental results in this paper could provide reference for subsequent unsteady experiments. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： Adaptive blade Aerodynamic performance Experiment Flexible rib

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Promotional effect of tungsten modification on magnetic iron oxide catalyst for selective catalytic reduction of NO with NH3

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JOURNAL OF THE ENERGY INSTITUTE 2020年第5期93卷 1809-1818页

作者： Li, Cheng-xu Xiong, Zhi-bo Du, Yan-ping Ning, Xing Li, Zhen-zhuang He, Jun-fei Qu, Xiao-ke Lu, Wei Wu, Shui-mu Tan, Lu-zhi Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai 200093 Peoples R China Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China Shanghai Jiao Tong Univ China UK Low Carbon Coll Shanghai 200240 Peoples R China SPIC Powder Plant Operat Technol Beijing Co Ltd Beijing 102209 Peoples R China Ludong Univ Sch Food Engn Yantai 264000 Peoples R China

A novel tungsten-doped magnetic iron oxide catalyst was fabricated for selective catalytic reduction of NOx with NH3 (NH3-SCR), which was supported by carbon-included magnetic materials of Fe2O3-H synthesized by the solution combustion followed by the oxidization of hydrogen peroxide. As a consequence, the thermal stability of gamma-Fe2O3 crystallites located in the magnetic support is significantly enhanced. Meanwhile, the irreversible transformation of Fe2O3 crystallites from gamma-phase to alpha-phase during the annealing process at high temperatures (i.e. 400 degrees C) is restrained to a large extent. In addition, the magnetic W/Fe2O3 catalyst presents a superb porous structure with higher BET surface area and pore volume due to the anti-sintering effect of tungsten doping on the magnetic Fe2O3. In this regard, the surface acidity as well as the molar ratio of the surface-adsorbed oxygen is substantially augmented, leading to a remarkable improvement of the redox ability of the active bulk species in the catalyst. It is worth mentioning that the promotions in thermal stability and redox ability is affected by the doping amount of tungsten in the catalyst, the molar ratio of glucose/urea/iron, and the ignition temperature for synthesizing the magnetic iron oxide support. The experiments revealed that with a doping amount of 7.5 wt%, a molar ratio of glucose/urea/iron of 5:20:8, and an ignition temperature of 400 degrees C, the NH3-SCR activity of the novel catalyst could be optimized. (C) 2020 Energy Institute. Published by Elsevier Ltd. All rights reserved.

关键词： Tungsten doped iron-oxide catalyst NH3-SCR Thermal stability Redox ability Activity optimization

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heat transfer enhancement of plate heat exchangers with symmetrically distributed capsules to generate counter-rotating vortices

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INTERNATIONAL JOURNAL OF heat AND MASS transfer 2020年第0期151卷 119455-000页

作者： Jiang, Chen Bai, Bofeng Wang, Haibo Shi, Jiqing Tang, Xiaoying Zhou, Wenxue Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian 710049 Peoples R China Shanghai Lanbin Petrochem Equipment CO LTD Shanghai 201518 Peoples R China Machinery Ind Shanghai Lanya Petrochem Equipment Shanghai 201518 Peoples R China Shanghai Inst Equipments Inspect & Tech Res Shanghai 200062 Peoples R China Lanzhou Res Ctr Heat Transfer & Energy Conservat Lanzhou 730050 Peoples R China

Capsule-type plate heat exchanger takes advantages of low flow resistance and high overall performance. To obtain greater energy efficiency, a new type named symmetrical capsule plate heat exchanger (SCPHE) is constructed based on the idea of counter-rotating vortices. For SCPHEs, the adjacent capsules distribute symmetrically at the same-side of the plate, and the capsules keep an angle of 45 degrees with the main flow direction. The heat transfer enhancement and the influences of capsule geometries were studied numerically. Counter-rotating vortices generating in the channels promote the swirl flow and disturb the boundary layer. Both fluid impinging and the vortices dominate the heat transfer enhancement, which become much stronger under smaller capsule, resulting in higher heat transfer coefficient. The correlations of Nu and f considering the effects of the capsule geometries are developed. SCPHEs show higher energy efficiency than capsule-type plate heat exchangers and chevron-type plate heat exchangers in the view of PEC and EEL. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Plate heat exchanger Symmetrical capsule Counter-rotating vortices Fluid impingement Energy efficiency

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Fluoride-Salt-Cooled High-Temperature Reactor: An Integrated Nuclear-Based Energy Production and Conversion System

SSRN

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SSRN 2023年

作者： Zhang, Dalin Li, Xinyu Jiang, Dianqiang Zhou, Xingguang Lv, Xindi Yun, Shichang Wu, Wenqiang He, Xuanang Li, Haoyang Min, Xin Chen, Kailong Tian, Wenxi Qiu, Suizheng Su, Guanghui Zhao, Quanbin Fu, Yao Tang, Chuntao Zhuo, Wenbin Li, Jinggang Zuo, Jiaxu State Key Laboratory of Multiphase Flow in Power Engineering Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology School of Nuclear Science and Technology Xi’an Jiaotong University Xi’an710049 China Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai201800 China Shanghai Nuclear Engineering Research & Design Institute Co. Ltd. Shanghai200233 China CNNC Key Laboratory on Nuclear Reactor Thermal Hydraulics Technology Nuclear Power Institute of China Chengdu610213 China China Nuclear Power Technology Research Institute Guangdong Shenzhen518000 China Nuclear and Radiation Safety Center Ministry of Ecology and Environment Beijing100082 China

Based on the analysis of energy structure and the development trends of advanced nuclear energy technology, combining the complementary advantages of nuclear energy and other energy sources in China, the Fluoride-salt-cooled High-temperature Reactor(FuSTAR) system has been proposed. FuSTAR system is designed to address production capacity issues in areas with energy shortages or resource concentration and can be combined with high-temperature process heat to achieve high-value-added processes such as hydrogen production. In this paper, the design and optimization processes of FuSTAR are described from three aspects: the neutronic and thermal-hydraulic system, the thermal transport system, and the power cycle system. Tri-structural isotropic fuel combined with helical cruciform elements has been studied in detail on the neutron physics and thermal-hydraulic properties, and the flow and heat transfer experiment is carried out for the first time. The multilayer nonlinear programming method has been applied to the design of thermal transport systems and the passive residual heat removal system and proved to be fast and efficient. Then the optimal parameters and configuration of the thermoelectric conversion system are obtained directly by using the superstructure optimization method, which saves computing resources greatly. Based on the above design and parameters, the inherent safety of FuSTAR is demonstrated through deterministic safety analysis. In addition, the iodine-sulfur cycle technology is also designed and analyzed, and the characteristics of tritium production in FuSTAR are calculated. The research provides important guidance for the detailed design and operation of FuSTAR. Moreover, this study highlights the significant potential of integrating nuclear energy with other energy sources in an optimized energy-production system. Based on the current research findings, prospects for future research directions are also suggested. © 2023, The Authors. All rights r

关键词： High temperature reactors

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Numerical Investigation of flow Dynamics and Cooling Performance in Combined Porosity Structures at the Leading Edge of a Hypersonic Vehicle

SSRN

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SSRN 2024年

作者： Chen, Weijie Tu, Shantung Chu, Tiange Su, Huijuan Wang, Ke Wang, Yongqing School of Mechanics and Safety Engineering Zhengzhou University Zhengzhou450001 China School of Mechanical and Power Engineering Zhengzhou University Zhengzhou450001 China Key Laboratory of Process Heat Transfer and Energy Saving of Henan Province Zhengzhou University Zhengzhou450002 China East China University of Science & Technology Shanghai200237 China Faculty of Arts Science & Technology University of Northampton Northampton United Kingdom

Transpiration cooling presents significant promise for enhancing thermal protection technology (TPT) in hypersonic vehicles. However, leading edge structures with single-homogeneous porosity (LE-SHP) frequently encounter excessive flow resistance at the stagnation point, resulting in non-uniform temperature distribution in localized regions, which adversely influences the TPT effectiveness. In response, a gradient-homogeneous combined porosity structure (LE-GHP) based on local thermal equilibrium (LTE) model was introduced in this paper. The cooling mechanism of LE-GHP at Mach 7 was analyzed using a step-by-step numerical simulation method. The effects of coolant injection rate and combined porosity distribution on coolant flow and cooling performance were investigated. Furthermore, the impact of discontinuous transpiration surfaces (GHP-DT) with varying lengths (‌δ) on downstream cooling performance was evaluated. The results indicate that flow resistance at the stagnation point is reduced by LE-GHP, forming a more uniform cooling gas film that significantly mitigates the thermal impact of high-enthalpy freestream on the transpiration surface. Compared to the LE-SHP, superior cooling performance with lower endothermic power under different coolant injection rate conditions are demonstrated by LE-GHP, improving the temperature distribution uniformity of the transpiration surface by 30.56-70.79% and increasing the average cooling efficiency of the hot surface by 11.48-13.01%. Additionally, when the gradient porosity region ranges from 0° to 60° (θ=60°), the endothermic power of transpiration surface is reduced by up to 64.88%, with a corresponding increase in the thermal protection effect on the hot surface by up to 28.17%. In comparison to θ=60°, GHP-DT (θ=60°, ‌δ=1 mm) not only ensures the reliability of thermal protection material, but also improves the temperature distribution uniformity of hot surface by 18.36%. This research provides valuable insights into the

关键词： Hypersonic vehicles

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