Ordinal Optimization Theory Based Planning for Clustered Wind Farms Considering the Capacity Credit

Wang, Yi,Zhang, Ning,Kang, Chongqing,Xu, Qianyao,Li, Hui,Xiao, Jinyu,Wang, Zhidong,Shi, Rui,Wang, Shuai The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.5

Wind power planning aims to locate and size wind farms optimally. Traditionally, wind power planners tend to choose the wind farms with the richest wind resources to maximize the energy benefit. However, the capacity benefit of wind power should also be considered in large-scale clustered wind farm planning because the correlation among the wind farms exerts an obvious influence on the capacity benefit brought about by the combined wind power. This paper proposes a planning model considering both the energy and the capacity benefit of the wind farms. The capacity benefit is evaluated by the wind power capacity credit. The Ordinal Optimization (OO) Theory, capable of handling problems with non-analytical forms, is applied to address the model. To verify the feasibility and advantages of the model, the proposed model is compared with a widely used genetic algorithm (GA) via a modified IEEE RTS-79 system and the real world case of Ningxia, China. The results show that the diversity of the wind farm enhances the capacity credit of wind power.

Green catalyst derived from zero‑valent iron onto porous biochar for removal of Rhodamine B from aqueous solution in a Fenton‑like process

Chongqing Wang,Pau Loke Show,Xiuxiu Zhang,Yijun Cao,Yasser Vasseghian 한국탄소학회 2023 Carbon Letters Vol.33 No.7

Organic wastewater causes serious environmental pollution, and catalytic oxidation is promising technique for wastewater treatment. Developing green and effective catalysts is currently challenging. In this work, green synthesis of nano zerovalent iron loaded onto porous biochar derived from popcorn is conducted, and catalytic oxidation of Rhodamine B (RhB) is evaluated in the presence of H2O2. Effect of process factors is examined on catalytic performance for RhB removal. The mechanism of RhB removal is discussed by characterizations (Fourier transform infrared spectra and Raman) and UV–vis spectra. RhB removal is improved with high catalyst dosage, low initial RhB concentration, and high reaction temperature, while it is slightly influenced by carbonization temperature of biochar, H2O2 dosage and pH value. Under conditions of BC-250 1.0 g/L, H2O2 0.01 mol/L, pH 6.1, and temperature 30 °C, the removal rate of RhB is 92.27% at 50 min. Pseudo first-order kinetics is used to fitting experimental data, and the activation energy for RhB removal in BC-250/H2O2 system is 39 kJ/mol. RhB removal in BC-250/H2O2 system can be attributed to adsorption effect and catalytic oxidation with the dominant role of hydroxyl radical. This work gives insights into catalytic oxidation of organic wastewater using green catalyst.

Ordinal Optimization Theory Based Planning for Clustered Wind Farms Considering the Capacity Credit

Yi Wang,Ning Zhang,Chongqing Kang,Qianyao Xu,Hui Li,Jinyu Xiao,Zhidong Wang,Rui Shi,Shuai Wang 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.5

Wind power planning aims to locate and size wind farms optimally. Traditionally, wind power planners tend to choose the wind farms with the richest wind resources to maximize the energy benefit. However, the capacity benefit of wind power should also be considered in large-scale clustered wind farm planning because the correlation among the wind farms exerts an obvious influence on the capacity benefit brought about by the combined wind power. This paper proposes a planning model considering both the energy and the capacity benefit of the wind farms. The capacity benefit is evaluated by the wind power capacity credit. The Ordinal Optimization (OO) Theory, capable of handling problems with non-analytical forms, is applied to address the model. To verify the feasibility and advantages of the model, the proposed model is compared with a widely used genetic algorithm (GA) via a modified IEEE RTS-79 system and the real world case of Ningxia, China. The results show that the diversity of the wind farm enhances the capacity credit of wind power.

Contact modeling and stiffness of a rough surface under mixed lubrication condition

Ling Li,Litai Sun,Jingjing Wang,Benshuai He,Chongqing Fan,Lixia Li,Miaoxia Xie 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.2

A method of using a quadratic function of rotary asperities to be equivalent to asperity is established based on a measurement experiment on rough surface topography. A micro-contact model of a rough surface that includes elastic, elastic-plastic, and pure plastic deformation states is re-derived using the theory of contact mechanics and the method of probability statistics. A rough surface contact stiffness model under mixed lubrication is proposed in accordance with the rough surface contact stiffness, which consists of solid surface and lubrication medium contact stiffness. The influence of the lubrication medium, solid material, and asperity size parameters on contact stiffness is analyzed. Results show that elastic modulus, acoustic impedance, and the size parameters of the asperities of the solid part are the main factors that affect the contact stiffness of the solid part. The acoustic impedance of the lubricating medium mainly affects the contact stiffness of the lubrication part. The contact stiffness of the rough surface under mixed lubrication is a superposition of the solid and lubrication parts, and it is greater than that without the lubrication medium. The model established in this study fully considers the deformation state in practical engineering, which includes asperities and the lubrication state of rough surfaces. It provides a reference for the performance prediction of mechanical surfaces.

Two-step continuous synthesis of tetraethylthiuram disulfide in microstructured reactors

Xingjun Yao,Lixiong Zhang,Changfeng Zeng,Chongqing Wang 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.3

Microstructured Reactor, N, N-diethyldithiocarbamic Acid, Tetraethylthiuram Disulfide, Vulcanization Accelerator,Strongly Exothermal

Modeling and Performance Analysis of MAC Protocol for WBAN with Finite Buffer

( Minglei Shu ),( Dongfeng Yuan ),( Changfang Chen ),( Yinglong Wang ),( Chongqing Zhang ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.11

The IEEE 802.15.6 standard is introduced to satisfy all the requirements for monitoring systems operating in, on, or around the human body. In this paper, analytical models are developed for evaluating the performance of the IEEE 802.15.6 CSMA/CA-based medium access control protocol for wireless body area networks (WBAN) under unsaturation condition. We employ a three-dimensional Markov chain to model the backoff procedure, and an M/G/1/K queuing system to describe the packet queues in the buffer. The throughput and delay performances of WBAN operating in the beacon mode are analyzed in heterogeneous network comprised of different user priorities. Simulation results are included to demonstrate the accuracy of the proposed analytical model.

High-performance ZIF-302 mixed-matrix membranes for efficient CO2 capture

Junfeng Qian,Eryue Song,Haiqian Lian,Jinlong Jiang,Chongqing Wang,Yichang Pan 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.4

High-performance mixed matrix membranes (MMMs) were developed to assist in controlling global warmingby capturing carbon dioxide (CO2) from moist flue gas. However, the separation performance of MMMs has alwaysbeen limited by gas permeability and long-term operating stability under humid conditions. ZIF-302 is a novel chabazite(CHA) topology structure with hydrophobic ligand. Herein, uniform ZIF-302 nanocrystals were doped into theP84 polymer matrix to synthesize different content of defect-free ZIF-302/P84 MMMs for CO2/N2 separation. A significantcombination of gas permeability and separation factors was found in MMMs with a ZIF-302 packing load of 30wt%. The gas permeability of CO2 and the separation factor of CO2/N2 were significantly increased to 5.2 Barrers and46, respectively, which breaks the trade-off between permeability and selectivity of the polymer membrane. In addition,the long-term operation stability showed that the separation performance of ZIF-302/P84 MMMs for CO2/N2 was maintainedmore than 30 h at 3 bar and 60 oC. The main characteristics of the MMMs prepared in this paper include the combinationof favorable structural stability under humid conditions and unaffected CO2/N2 gas separation performance.

Iron-loaded carbon derived from separated microplastics for heterogeneous Fenton degradation of tetracycline hydrochloride

Liu Hongwen,Li Xingyang,Li Guosheng,Yasser Vasseghian,Wang Chongqing 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.12

Microplastics are gaining growing research interest due to their significant potential threats to ecosystems and public health. Physical techniques have been proposed as a promising strategy for removing microplastics from the environment. This work innovatively proposes a process of microplastic removal by froth flotation and subsequent carbonization for synthesis of heterogeneous Fenton catalyst. The feasibility of separating different microplastics from water was verified by froth flotation, and iron-loaded carbon derived from separated microplastics was fabricated as catalyst. Carbon material was obtained by carbonization of microplastics, and iron loading was conducted to improve catalytic ability. The catalyst of iron-loaded iron was characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The degradation of tetracycline hydrochloride in the heterogeneous Fenton system was evaluated by single factor experiment and kinetic analysis. The catalytic performance was mainly influenced by H2O2 concentration, solution pH, and co-existing ions. Under the conditions of catalyst 20 mg/L, H2O2 concentration 0.99 mmol/L, initial tetracycline hydrochloride concentration 20 mg/L, pH 4.0, and temperature 25 °C, the removal rate of tetracycline hydrochloride within 15 min reached 81.6%, and the rate constant was 0.138min−1. The catalytic mechanism dominated by hydroxyl radical was verified for the degradation of tetracycline hydrochloride. This work offers insights into the management of microplastics and sustainable treatment of antibiotic wastewater.