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Investigation of exergy efficiency of organic Rankine cycle

IOP Conference Series: Earth and Environmental Science 2019年第1期354卷

作者： G L Liu J L Xu S Cao Beijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy Utilization North China Electric Power University Beijing 102206 Beijing China School of Energy and Power Engineering Zhengzhou University of Light Industry Zhengzhou 450002 Henan Province China

Organic Rankine cycle (ORC) which recovers waste heat in the temperature range of 80°C-140°C was investigated. Exergy efficiencies of various components and ORC system were paid great attention. The working fluids of R245fa and R600a are used. It is found that, for saturated ORCs, the expander inlet temperature has the optimum value, so the system exergy efficiency is maximum. With the increase of heat source temperature, the optimal inlet temperature of the expander is also increased. And also for saturated ORCs, the exergy efficiencies of evaporator and expander are highest efficiency, when evaporator exergy efficiency is increased with increase of heat source temperatures, the expander exergy efficiency is unchanged. The condenser decreased exergy efficiencies by increasing the heat source temperatures.

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Study on measurement of 3D movement for particles based on defocused image

Study on measurement of 3D movement for particles based on d...

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The 14th Asian Symposium on Visualization

作者： Minhua Jia Wu Zhou Xiaoshu Cai Institute of Particle and Two-phase Flow Measurement Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power EngineeringUniversity of Shanghai for Science & Technology

Based on the principle of depth from defocus,a three-dimensional positioning method based on two images with different degrees of blur was proposed for moving *** theoretical analysis,simulation work and experimental study of the 3 D movement measurement for micrometer-sized particles are carried out,respectively.A system was established for measuring experiments of three-dimensional particle movement,using single lens and dual *** distance between the lens and one of the cameras was adjusted by increasing the spacers of different *** the same object distance,two images with different degree of blur were *** image was transformed into gradient image by the adaptive edge detection algorithm based on gradient *** on the theory of moment invariants,the bright area of the image edge compared to the whole image is calculated,and the ratio of the two defocus radius α is *** to the formula of the object distance u,the depth position of the particle can be realized without *** order to verify the feasibility of the system,the simulation studies were conducted based on the calibrated parameters of the system,and images of the standard dots of 45μm to 2000μm were captured and processed for *** results show that during simulation,the error is less than 2% in 15 times depth of field of the imaging system,and the error in experiments is less than 8% in 12 times of depth of *** the results show that the size of particles has little effect on the accuracy of the method.

关键词： 3D movement defocused image moment-invariants degree of blur

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A depth estimation algorithm of plenoptic camera for the measurement of particles

A depth estimation algorithm of plenoptic camera for the mea...

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IEEE International Workshop on Imaging Systems and Techniques (IST)

作者： Yuanchi Ma Wu Zhou Tianlei Qian Xiaoshu Cai Institute of Particle and Two-phase Flow Measurement / Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering University of Shanghai for Science and Technology shanghai China

Plenoptic camera has been widely studied in many areas such as circuit analysis, microbiological detection and remote sensing. But the application of plenoptic camera was rarely get attention in three-dimensional measuring for particles and fluid. The applicability and accuracy of existing algorithm for depth estimation and three-dimensional measuring is acceptable [8]. However, the traditional algorithm for depth estimation is not suitable for measuring of particles and fluid in the result of some differences between particles and other kinds of objects in three-dimensional measuring with plenoptic cameras especially in the case of low density of particles system. This paper presents an improved depth estimation algorithm of plenoptic camera for the measurement of particles. This improved algorithm can effectively restrain miscalculation of depth by pretreatment and searching for the area of maximum gradient. The improvement of accuracy and precision of this depth estimation algorithm compared with the traditional algorithm was proved by a series of experiments.

关键词： Cameras Particle measurements Atmospheric measurements Estimation Lenses Calibration Area measurement

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Simultaneous measurement of film thickness, temperature, and mass fraction of urea-water-solutions by multi-wavelength laser absorption spectroscopy

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REVIEW OF SCIENTIFIC INSTRUMENTS 2017年第5期88卷 053102页

作者： Yang, Huinan Shi, Jianwei Su, Mingxu Wu, Wei Cai, Xiaoshu 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

Quantitative analysis for thickness, temperature, and mass fraction of liquid film is extremely crucial to the relevant industrial processes, but these parameters cannot be determined simultaneously by conventional measurement techniques. In the present work, a novel measurement method based on laser absorption spectroscopy was developed to measure the film temperature, thickness, and mass fraction of urea-water-solutions simultaneously by combining three wavelengths, 1420 nm, 1488 nm, and 1531 nm. Moreover, measurement accuracy of this method was validated by a calibration tool which provided liquid film with known film thickness, temperature, and mass fraction, respectively. It revealed that the deviation between the measured and known parameters with the developed method was 0.86%, 4.58%, and 3.85%, respectively. Published by AIP Publishing.

关键词： Urea

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Model for seawater fouling and effects of temperature,flow velocity and surface free energy on seawater fouling

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Chinese Journal of Chemical engineering 2016年第5期24卷 658-664页

作者： Dazhang Yang Jianhua Liu Xiaoxue E Linlin Jiang School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Key Laboratory of Multi-phase Flow and Heat Transfer Shanghai 200093China

A kinetic model was proposed to predict the seawater fouling process in the seawater heat *** new model adopted an expression combining depositional and removal behaviors for seawater fouling based on the Kern–Seaton *** present model parameters include the integrated kinetic rate of deposition(k d)and the integrated kinetic rate of removal(k r),which have clear physical signi ficance.A seawater-fouling monitoring device was established to validate the *** experimental data were well fitted to the model,and the parameters were obtained in different *** and EDX analyses were performed after the experiments,and the results show that the main components of seawater fouling are magnesium hydroxide and aluminum *** effects of surface temperature,flow velocity and surface free energy were assessed by the model and the experimental *** results indicate that the seawater fouling becomes aggravated as the surface temperature increased in a certain range,and the seawater fouling resistance reduced as the flow velocity of seawater ***,the effect of the surface free energy of metals was analyzed,showing that the lower surface free energy mitigates the seawater fouling accumulation.

关键词： Fouling Seawater Model Surface temperature flow velocity Surface free energy

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Pressurized oxy-fuel combustion performance of pulverized coal for CO₂ capture

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APPLIED THERMAL engineering 2016年 99卷 411-418页

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

Pulverized coal combustion in pressurized oxy-fuel (or O-2/CO2) atmosphere is widely accepted as a clean technique for energy conversion with respect to the NOx emission reduction and CO2 capture. The combustion performance of two pulverized coals, including the ignition and burnout, char structure transformation, and ash formation, was investigated, and the effects of system pressure, oxygen concentration, and coal type were explored. Results showed that system pressure had positive effects on the combustion performance of DT coal and SH coal within a range. The best pressure in this work was 1 MPa. The increase of oxygen concentration was more effective for the ignition temperature reduction at elevated pressure. Increasing the pressure affected the release of carbon functional groups on char surface, especially the aromatic and aliphatic carbon, which was least at 1 MPa, indicating the lowest graphitization degree and ignition temperature. A pressurized condition also promoted fragmentation of coal during the devolatilization, and thus enlarged the available surface area for char reaction with O-2, leading to an earlier ignition. The SEM morphologies of ash generated at different pressures identified the enhanced formation of finer ash under pressurized conditions. Results are feasible for optimizing the pressurized oxy-fuel combustion in the future. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Pressurized oxy-fuel combustion Pulverized coal Combustion performance Char structure Carbon functional groups Ash

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Characterization of soot based on variable laser-induced spectroscopy

Characterization of soot based on variable laser-induced spe...

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Digital Holography and Three-Dimensional Imaging, DH 2016

作者： Chen, Jun Zhang, Yanfeng Yan, Huinan Su, Mingxu School of Energy and Power Engineering Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering China

The soot raise great environmental and health problems. Conventional methods don ' t have such low measurement limits. So in this paper soot's component and size information will be studied in theory and exper... 详细信息

ISBN: (纸本)9781943580156

关键词： Soot

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New method for harvesting energy from fluid flow based on undulatory motion

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INTERNATIONAL JOURNAL OF GREEN ENERGY 2017年第6期14卷 540-547页

作者： Huang, Diangui Zhang, Jihua Sun, Xiaojing Univ Shanghai Sci & Technol Sch Energy & Power Engn 516 Jungong Rd Shanghai 200093 Peoples R China Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai Peoples R China

In nature, fish have gained wonderful swimming ability over the thousands of years of evolution. As the fish swims, its body, namely, it's dorsal or tail fin undulates and then alternating waves are sent down the body towards the tip of the tail. These waves generate a jet in the wake and hence a forward force, namely thrust. Scientific studies have already shown that undulatory swimming is a highly effective means of continuous locomotion and has been successfully adopted in many kinds of robotic fishes currently being developed. However, our latest research found that if wave velocity that defines the undulatory motion of the body or the 'fin' is less than a specific value, the fishlike body with undulatory motion also has the capability to harvest kinetic energy from flowing fluid. This finding proposes a new energy-harvesting concept which could offer a new and promising solution to support the long-distance voyage of a biomimetic robotic fish.

关键词： Dimensionless wave velocity energy harvest energy utilization efficiency fishlike body motion maximum amplitude

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An LP-DOAS instrument with a laser driven light source for open-path measurement of atmospheric NO2 in shanghai

An LP-DOAS instrument with a laser driven light source for o...

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Progress in Electromagnetic Research Symposium (PIERS)

作者： Mingzhi Li Jun Chen Mingxu Su Huinan Yang Arun Ramachandran Ravi Varma Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering University of Shanghai for Science and Technology Shanghai China Department of Physics National Institute of Technology Calicut Calicut Kerala India

shanghai is currently faced with the complex atmospheric pollution problem such as ozone (O 3 ) and PM2.5. O 3 is responsible for oxidization of atmospheric constituents that in turn produces secondary pollutants. Reducing atmospheric oxidation is the underpinning strategy for the prevention and control of pollution in this city. According to the observation data from the online automatic monitoring station of shanghai, the city's O 3 concentration has been rising steadily. In 2013, there are 100 days with ozone as the main pollutants, accounted for 31.9%. By Leighton relationship (K 6 [O 3 ][NO]=K 4 [NO 2 ] = 1), concentration of O 3 is closely related to that of NO 2 . So, continuous monitoring of atmospheric NO 2 has important significance. An instrument was developed for measuring atmospheric NO 2 concentration using a powerful light source in conjunction with the long-path differential optical absorption spectroscopy (LP-DOAS) technique. This system installed at the central section of shanghai used a laser driven light source (LDLS) and a sensitive TE cooled spectrometer. The LDLS showed better stability, high optical efficiency when compared to traditional arc lamp and light emitting diodes. The light sent into the atmosphere was returned by a retro reflecting mirror placed 1.3km away, and the light returned was sent to a high sensitive TE cooled spectrometer. The spectral range of measurement was 415-455nm and the spectra collected were averaged over 10 min, prior to analyzing for NO 2 concentration. Continuous observations were carried out for two weeks and the NO 2 concentration retrieved ranged from (20-600) ug/m3 with an estimated detection limit of 6.77 ug/m3. The measurement results indicate that it is feasible to use this instrument for detecting the NO 2 with high spatial and temporal sensitivity.

关键词： Absorption Atmospheric measurements Light sources Pollution measurement Optical sensors Wavelength measurement Instruments

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Experimental study of composition and influence factors on fouling of stainless steel and copper in seawater

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ANNALS OF NUCLEAR ENERGY 2016年 94卷 767-772页

作者： Yang, Dazhang Liu, Jianhua E, Xiaoxue Jiang, Linlin Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai Peoples R China Key Lab Multiphase Flow & Heat Transfer Shanghai Shanghai Peoples R China

Metals and alloys are easily fouled in marine environment. It is a big problem for heat exchangers using cooling seawater in power plants or ships. In the paper, a seawater-fouling dynamic test device was built to investigate the composition and influence factors on fouling of stainless steel and copper in the cooling seawater system. Moreover, the static trials were performed to study the fouling and corrosion of stainless steel and copper in marine environment. The experimental results show that the seawater fouling of stainless steel is crystallization fouling, and the main elements of fouling are magnesium and aluminum. In addition, the results show that the seawater fouling of copper is corrosion fouling. In the dynamic experiments, the effects of heat flux and Reynolds number on stainless steel fouling were studied. The results show that higher heat flux and higher Reynolds number of seawater lead to the accumulation of seawater fouling. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Fouling Seawater Composition Influence factor Stainless steel Copper

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