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Feasibility and improvement of fault detection and diagnosis based on factory-installed sensors for chillers

APPLIED THERMAL engineering 2020年 164卷 114506-000页

作者： Fan, Yuqiang Cui, Xiaoyu Han, Hua Lu, Hailong Univ Shanghai Sci & Technol Sch Energy & Power Engn 516 Jungong Rd Shanghai 200093 Peoples R China Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China CQ Midea Gen Refrigerat Equipment CO LTD 15 Qiangwei Rd Chongqing 401336 Peoples R China

As noted in this investigation, there are only eight sensors commonly installed in factory chillers. However, the fault detection and diagnosis (FDD) models of chillers are now mostly based on laboratory data. In the laboratory, the unit is equipped with more sensors than commercial machines are. The FDD results obtained by this method does not match the data from the factory chillers and cannot be applied in practice. Based on the ASHRAE RP-1043 data, this paper extracts information from three of the factory-installed (FI) sensors, along with information from all eight of the FI sensors, in order to establish the support vector machine (SVM)-3 and SVM-8 diagnostic models based on grid search and cross validation parameter optimization for the seven typical faults. These models are compared to the SVM-64 model, which is based on the 64 parameters from the ASHRAE data. The overall accuracy of SVM-8 model is 97.68%, which meets the needs of field operation diagnosis. In addition, based on the eight factory-installed sensors, if the pressure of oil feed and temperature of oil feed sensors are added together to diagnose the fault, the normal detection rate and the diagnostic performance for condenser fouling and excess oil faults improve, and the overall fault diagnosis is more effective.

关键词： Chiller Factory-installed sensors Support vector machine (SVM) Fault detection and diagnosis (FDD) Model

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Study on TMD Control on Stability Improvement of Barge-Supported Floating Offshore Wind Turbine Based on the Multi-Island Genetic Algorithm

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China Ocean engineering 2019年第3期33卷 309-321页

作者： DING Qin-wei LI Chun CHENG Shan-shan HAO Wen-xing HUANG Zhi-qian YU Wan School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai 200093 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai 200093 China School of Engineering University of Plymouth Devon PL4 8AA UK

A floating offshore wind turbine (FOWT) has a great potential in producing renewable energy as offshore wind resource is rich in deep sea area (water deeper than 60 m) where fixed foundations are cost-effective or deployable. However, compared with a fixed-bottom installation, FOWT has to suffer more extreme loads due to its extra degrees of freedom. Therefore, the stability of an FOWT is a key challenge in exploiting offshore deep-water wind. Focusing on the stability of barge-type FOWT, this paper is to investigate the effect of passive structural control by equipping a tuned mass damper (TMD) on the nacelle. The turbulent wind with sharp fluctuations is established both in velocity and inflow direction based on standard Kaimal turbulence spectrum as suggested in the standard IEC61400-2. The irregular wave is generated according to the Pierson-Moskowitz spectrum. The dynamic structural characteristics of FOWT are calculated based on the fully coupled aero-hydro-servo-elastic solver FAST. Evidence has shown that the proposed method of the nacelle-based TMD is effective in controlling stability of an FOWT, as the sway and roll motions of barge and the side-side displacement of tower top decreased significantly. With the increase of mass, the side-side displacement of tower-top and the amplitude of roll motion of barge reveal a trend of increasing first and then decreasing. The stiffness and damping have little effect. Furthermore, the multi-island genetic optimization algorithm (MIGA) is employed to find globally optimum structural parameters (mass, stiffness and damping) of the TMD. The optimum structure parameters of TMD are achieved when the mass is 21393 kg, damping is 13635 N/(m/s) and stiffness is 6828 N/m. By adopting the optimized TMD, stability of roll motion of barge and side-side displacement of tower-top increase up to 53% and 50% respectively when compared with the normal TMD. The simulation results verify the validity and reliability of the proposed TM

关键词： FOWT barge TMD MIGA wind wave stability

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Boiling of Water Droplet in Glass-Oil-Water multiphase System

SSRN

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SSRN 2022年

作者： He, Xiaotian Cheng, Yiwei Xu, Jinliang Yu, Xiongjiang Xie, Jian Ma, Xiaojing Ren, Yong Beijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy Utilization North China Electric Power University Beijing102206 China Key Laboratory of Power Station Energy Transfer Conversion and System of Ministry of Education North China Electric Power University Beijing102206 China Research Group for Fluids and Thermal Engineering University of Nottingham Ningbo China Ningbo315100 China

Boiling of a volatile droplet in a non-volatile liquid becomes complex due to various interface interactions in a solid-liquid-liquid system. Available studies reported explosive boiling and attributed the phenomenon to heterogeneous nucleation due to solid-liquid contact. Here, we investigate boiling of ~2 mm diameter water droplet in a silicon oil pool with glass container. Two transition temperatures are observed, with one as the transition from evaporation to boiling (122.5 o C), and the other as the transition from bubble growth in oil side to that in both oil and water side (160.0 o C). Correspondingly, four boiling modes of evaporation (E), boiling in water (BIW: bubble nucleation at glass-water interface and growth inside drop), boiling in oil (BIO: nucleation at oil-water interface and growth in oil), and boiling in oil and water (BIOW: nucleation at oil-water interface and growth in oil and water), are identified. For the first time, boiling bifurcation is found for drop boiling in a three-phase system. For oil temperature T b in the range of (122.5~160.0) o C, boiling mode switches in between BIW and BIO. On the contrary, for T b beyond of 160.0 o C, either BIW or BIOW occurs. This bifurcation is explained by the fact that a droplet prefers to choose smaller activation energy between that for bubble nucleation at solid-water interface and that for bubble nucleation at oil-water interface. Interfacial instabilities are analyzed to explain why BIOW boils more violently than BIW. Our work presents a comprehensive understanding of droplet boiling in the three-phase system. © 2022, The Authors. All rights reserved.

关键词： Bifurcation (mathematics)

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Nanosized caltrops enable selective capture and directional maneuvering of water droplets

COMMUNICATIONS MATERIALS

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COMMUNICATIONS MATERIALS 2024年第1期5卷 1-11页

作者： Cai, Haoting Tong, Wei Wei, Lichuan Song, Mengjie Zhao, Yugang Li, Kang Zhang, Hua Yang, Chun Cheng, Ping Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai Key Lab Multiphase Flow & Heat Transfer P Shanghai 200093 Peoples R China Shenzhen Envicool Technol Co Ltd Shenzhen 518129 Peoples R China Beijing Inst Technol Sch Mech Engn Dept Energy & Power Engn Beijing 10008L Peoples R China China Aerodynam Res & Dev Ctr Key Lab Icing & Anti Deicing Mianyang 621000 Sichuan Peoples R China Nanyang Technol Univ Sch Mech & Aerosp Engn Nanyang 639798 Singapore Shanghai Jiao Tong Univ Sch Mech Engn MOE Key Lab Power Machinery & Engn Shanghai 200240 Peoples R China

Surface design by tailoring topographical features and interface function groups to modulate dynamic or kinetic behaviors of liquid droplets, has been an increasing hotspot due to its broad spectrum of applications in biochemical diagnosis, microfabrication, and energy conversion systems. Here we report an engineered surface decorated by packed nanosized caltrops resulting from two perfectly articulated oxidation processes, where self-assembled nanoislands generated in the 1st plasma oxidation serve as protective masks in the 2nd chemical oxidation. As caltrops per design can effectively block lateral motion, the present surface can anchor contact lines of advancing water films when being hydrophilic and selectively capture impinging droplets when being hydrophobic. Furthermore, biphilic patterns can be readily obtained by integrating nanocaltrops with other surface asperities, engendering directional droplet maneuvering and designated droplet arraying. This work provides guidelines in designing nanostructures that achieve on-demand manipulation of droplets and flow patterns for multifunctional applications.

关键词： Oxidation

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An experimental investigation of composite phase change materials of ternary nitrate and expanded graphite for medium-temperature thermal energy storage

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SOLAR ENERGY 2020年 195卷 573-580页

作者： Lu, Wei Liu, Guizhi Xiong, Zhibo Wu, Zhigen Zhang, Guanhua 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 Tongji Univ State Key Lab Pollut Control & Resource Reuse Shanghai 200092 Peoples R China Shanghai Inst Pollut Control & Ecol Secur Shanghai 200092 Peoples R China

Utilization of KNO3-LiNO3-Ca(NO3)(2)/expanded graphite (EG) as composite phase change materials (PCMs) for medium-temperature thermal energy storage was investigated in this paper. The thermo-physical properties of KNO3-LiNO3-Ca(NO3)(2) with different proportions were investigated. EG was employed as an additive to enhance thermal conductivity of PCMs as it has high thermal conductivity and excellent thermo-chemical stability. Thermo-physical parameters such as phase transition temperature, latent heat of fusion, thermal conductivity and decomposition temperature were measured experimentally. The results showed that the phase transition temperature of this ternary nitrate (60.2 wt% KNO3-29.9 wt% LiNO3-9.9 wt% Ca(NO3)(2)) is lower than that of Solar Salt and Hitec Salt. The composites with more EG have higher thermal conductivity. However, the addition of EG reduces their decomposition temperature. Furthermore, the corrosion experiments with six types of metal samples embedded in liquid ternary nitrate at 480 degrees C for 1500 h were delivered to investigate their chemical stability. Moreover, the PCMs have good long-term high temperature stability during the process. The results of this work confirmed the great potentials of KNO3-LiNO3-Ca(NO3)(2)/EG as composite PCMs that can be applied for industrial waste heat energy recovery applications, the solar power generation system and medium-temperature thermal energy storage.

关键词： Phase change materials Expanded graphite Thermo-physical property Thermal stability

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An adaptable direct simulation Monte Carlo method for simulating acoustic agglomeration of solid particles

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CHEMICAL engineering SCIENCE 2022年 249卷 117298-117298页

作者： Wu, Zhihao Fan, Fengxian Yan, Jinpei Chen, Houtao Hu, Xiaohong Su, Mingxu 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 MNR Key Lab Global Change & Marine Atmospher Chem Inst Oceanog 3 Xiamen 361005 Peoples R China Hunan Prov Key Lab Efficient & Clean Thermal Powe Changsha 410007 Peoples R China

An adaptable direct simulation Monte Carlo (DSMC) method that settles the challenge of coexistence of agglomeration and rebound as a consequence of inter-particle collisions was developed to simulate acoustic agglomeration of solid particles. The method was validated against experimental data under a range of operational conditions. Based on this, the evolution of particle size distribution, agglomeration efficiency and agglomeration behavior with time was numerically investigated. The effect of restitution coefficient on the performance of acoustic agglomeration was also examined. The results show that the occurrence of acoustic agglomeration yields a significant decrease in the number concentration of small particles and a small increase in the number concentration of large particles. Moreover, a worse performance of acoustic agglomeration at a higher restitution coefficient is observed. This study demonstrated the power of the proposed method in simulating the acoustic agglomeration and provided a fundamental approach for investigating the dispersed gas-solid two-phase flows. (c) 2021 Elsevier Ltd. All rights reserved.

关键词： Direct simulation Monte Carlo (DSMC) method Agglomeration Rebound Inter-particle collision Acoustic field Gas-solid two-phase flow

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Corrosion behavior of brass in SCW-SDBS-TiO₂ nanofluid

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JOURNAL OF ALLOYS AND COMPOUNDS 2021年第Part2期855卷 157483-157483页

作者： Wu, Kai Zhang, Yi Ge, Fang Huang, Xin Ge, Hong-Hua Zhao, Yu-Zeng Meng, Xin-Jing Dou, Bin-Lin Shanghai Univ Elect Power Shanghai Engn Res Ctr Energy Saving Heat Exchange Shanghai Key Lab Mat Protect & Adv Mat Elect Powe Shanghai 200090 Peoples R China Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China

A stable TiO2 nanofluid with absolute value of Zeta potential greater than 44 mV was prepared by using sodium dodecylbenzene sulfonate (SDBS) as a dispersing agent in this paper. Electrochemical methods and surface analysis were used to study the corrosion behavior of brass in simulated cooling water (SCW), simulated cooling water containing SDSB (SCW-SDBS), and TiO2 nanofluid (SCW-SDBS-TiO2 nanofluid). The results show that the total resistance R-sum of the brass electrode was smallest and increased slowly with time, and the corrosion current density was largest in SCW. The corrosion products on the brass surface were composed of the inner layer of Cu2O and the outer layer of Zn-5(CO3)(2)(OH)(6). In SCW-SDBS medium, the R-sum value of brass increased rapidly in the first 4 days and was significantly higher than that in SCW. A protective adsorption SDBS film was formed on the brass surface and minimized the corrosion rate of brass in SCW-SDBS medium. In SCW-SDBS-TiO2 nanofluid, the R-sum value of brass was higher than that in SCW, but significantly lower than that in SCW-SDBS medium. There was almost no SDBS adsorption film formed on the brass surface in SCW-SDBS-TiO2 nanofluid, which significantly reduced the corrosion inhibition performance of SDBS on brass. The competitive adsorption of negatively charged TiO2 nanoparticles and SDBS anions in the nanofluid on the brass surface might be the reason why the protective SDBS adsorption film was not easy to form on the brass surface in SCWSDBS-TiO2 nanofluid. (C) 2020 Elsevier B.V. All rights reserved.

关键词： TiO2 nanofluid TiO2 nanoparticles SDBS Brass Corrosion

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Effect of Struvite Addition on Relieving the Slagging Tendency during Zhundong Coal Combustion

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ENERGY & FUELS 2019年第12期33卷 12251-12259页

作者： Yu, Zhihao Jin, Jing Yang, Haoran Zhang, Ruipu Hang, Yixuan Univ Shanghai Sci & Technol Shanghai Key Lab Multiphase Flow & Heat Transfer Sch Energy & Power Engn Shanghai 200093 Peoples R China

Zhundong coal is a kind of high-quality power coal, but serious fouling and slagging may occur due to the rich content of alkali and alkali earth metals (AAEMs). Combustion experiments were carried out on an electrically heated tube furnace at different temperatures in air atmosphere. The raw coal and its mixtures with struvite additive (2-8 wt % of coal mass) were respectively burned in air atmosphere. Combustion-generated ashes were collected and analyzed by inductively coupled plasma optical emission spectroscopy, X-ray diffractometry, and scanning electron microscopy-energy dispersive spectroscopy. Results show that the mixed coal ash at high temperatures has a looser and more brittle structure than the raw coal ash and is more easily removed. With the introduction of struvite, whitlockite and chladniite appear, which improves the melting temperature of the mixed coal ash, while gehlenite (Ca2Al2SiO7) and akermanite (Ca2MgSiO7) disappear. The high content of calcium in Zhundong coal leads to the formation of a low-temperature eutectic with some minerals such as Al and Si at temperatures higher than 1000 degrees C. Ca separates out after these minerals melt, flows within the flue gas, and congeals on the heating surfaces, causing serious slagging. The fixation rate of Ca in the mixed coal ash blended with struvite increases obviously. The optimum addition of struvite is 4%.

关键词： Additives Coal Redox reactions Reaction products Minerals

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Research on aerodynamic performance of a novel dolphin head-shaped bionic airfoil

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ENERGY 2021年 214卷 118179-118179页

作者： Huang, Shengxian Hu, Yu Wang, Ying Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China Natl Key Lab Sci & Technol Aerodynam Design & Res Xian 710072 Peoples R China

Based on the special streamline profile of the Phocoenoides dalli head, this paper innovatively proposes to transform the NACA 0018 airfoil into a novel airfoil whose leading edge is similar to the streamline profile of the Phocoenoides dalli head, and makes corresponding minor adjustments to this new airfoil according to the dolphin's motion behavior, and eventually obtains three kinds of dolphin head-shaped new airfoils including the Original Dolphin Airfoil, the Smooth Transition Dolphin Airfoil and the Deflected Dolphin Airfoil. Due to different deflection angles, the Deflected Dolphin Airfoil is then subdivided into five different types. The aerodynamic performances of these three dolphin head-shaped new airfoils as well as the NACA 0018 airfoil are simulated by using the SST k-omega model at Re = 1.6 x 10(5). The results show that: Compared with the NACA 0018 airfoil, firstly, the aerodynamic performances of three kinds of dolphin head-shaped airfoils are quite different from each other because of the change of the curvature and the radius of the leading edge. Secondly, by comparing the lift and drag coefficients of the Deflected Dolphin Airfoils with five deflection angles, it is speculated that there is an optimal deflection angle for the Deflected Dolphin Airfoil under the conditions of this paper. Eventually, the deflection angle of 24 degrees is found to be the optimal value among these five different deflection angles. The results of this study can provide reference for improving the performance of blade design, such as the rotating mechanical blades, the aeronautical blades, etc. (C) 2020 Published by Elsevier Ltd.

关键词： engineering bionics Dolphin head-shaped airfoil Numerical simulation Aerodynamic performance Blade design method

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Three-dimensional electrochemical Bunsen reaction characteristics in the sulfur-iodine water splitting cycle for hydrogen production

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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 2019年第41期44卷 22841-22850页

作者： Ying, Zhi Zhang, Yao Zheng, Xiaoyuan Wang, Yabin Dou, Binlin Cui, Guomin Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China

Hydrogen production from the sulfur-iodine water splitting cycle integrated with solar or nuclear energy has been proposed as a promising technique. Bunsen reaction is one of the three main steps in the cycle and electrochemical method has been applied to this reac- tion. In present work, a three-dimensional numerical study of the electrochemical Bunsen reaction was conducted. A three-dimensional, steady state, laminar and isothermal mathematical model of electrolytic cell was developed and verified by experiments. The spatial maldistribution of species concentration was found between electrodes and proton exchange membrane (PEM). The electric power drives most H2SO4 and 12 to the anode and cathode surface, respectively, while the proton attraction contributes to HI enrichment on the surface of PEM. At the high inlet H2SO4 concentration of 50 wt%, the transformation of flow channel from single serpentine to single entry & double serpentine with the same inlet flow rate cannot solve the insufficient problem of SO2. But the increase of the overall inlet flow rate in the double entry & double serpentine flow channel make SO2 sufficient for anode reaction. Further decreasing the inlet H2SO4 concentration to 40 wt% and 30 wt% make the initial SO2 sufficient for overall reactions. The single serpentine channel gives the highest SO2 conversion rate, followed by the single entry & double serpentine and double entry & double serpentine flow channels. The single serpentine flow channel at the H2SO4 inlet concentration of 40 wt% is found optimal for achieving a high electrochemical Bunsen reaction performance. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

关键词： Hydrogen production Sulfur-iodine cycle Electrochemical bunsen reaction Electrolytic cell Three-dimensional

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