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Thermodynamic analysis of general heat engine cycle with finite heat capacity rates for power maximization

CASE STUDIES IN THERMAL ENGINEERING 2022年 35卷

作者： Kim, Soyeon Baik, Young-Jin Kim, Minsung Chung Ang Univ Dept Intelligent Energy & Ind 84 Heukseok Ro Seoul 06974 South Korea Korea Inst Energy Res Thermal Energy Convers Syst Lab 152 Gajeong Ro Dajeon 34129 South Korea Chung Ang Univ Sch Energy Syst Engn 84 Heukseok Ro Seoul 06974 South Korea

In this study, the ideal cycles with finite heat capacity rates is investigated theoretically to maximize power generation using a sequential Carnot cycle model. Although the Carnot efficiency is important, it is limited to evaluating only in terms of heat source/sink temperatures. For the actual heat engine, maximization of power generation is more important than cycle thermal efficiency when utilizing low-grade heat sources such as a waste heat. In this study, power generation optimization is numerically simulated under the fixed conditions of heat source temperatures, heat source flow rate and heat sink temperature. Effect by two design variables, compressor exit temperature and evaporator size ratio, were evaluated during cycle optimization. The optimization was performed using the pattern search algorithm (PSA) under a given thermal capacitance rate ratios and size of heat exchanger (UA) conditions. As a result, designing compressor exit temperature for maximizing the heat received from heat sources does not always maximize the power, but the higher the UA makes the optimum temperature lower, and the power output higher. These idealistic approaches can be useful in designing of cycle where the power maximization is crucial.

关键词： Power maximization Sequential carnot cycle Waste heat recovery pattern search algorithm Trilateral cycle

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Flame detection by heat from the infrared spectrum: Optimization and sensitivity analysis

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FIRE SAFETY JOURNAL 2022年第0期133卷 1页

作者： Bordbar, Hadi Alinejad, Farid Conley, Kevin Ala Nissila, Tapio Hostikka, Simo Aalto Univ Sch Engn Espoo Finland Aalto Univ Sch Chem Engn Dept Chem & Mat Sci Espoo Finland Aalto Univ QTF Ctr Excellence Dept Appl Phys POB 11000 FI-00076 Espoo Finland Loughborough Univ Interdisciplinary Ctr Math Modeling Loughborough LE11 3TU Leics England Loughborough Univ Dept Math Sci Loughborough LE11 3TU Leics England

Accurate detection of unwanted fires at their early stage is crucial for efficient mitigation and loss prevention. Moreover, the detection strategy must avoid false alarms and the associated disruptions in workplaces. Thermal radiation-based flame detection is the fastest detection method and is commonly used in critical industrial spaces, such as air hangars and petroleum manufacturing and storage. The main challenge is distinguishing the radiation of flames from other sources, e.g., hot objects or the Sun. The principles of radiation-based flame detection have been known for a long time, but open data and worked-out feasibility studies are rare. This work takes advantage of the recent advances in experimental and numerical methods of characterizing the infrared spectra. Combining high-resolution spectra from flames and blackbody emitters with virtual low-pass filters allows us to simulate the response of a hypothetical sensor. To maximize the difference between flame and blackbody responses, we use a pattern search algorithm to find optimal filtering wavelengths for two different detection strategies based on three or four optical low-pass filters. The optimal wavelengths are reported along with the sensitivity of the detection signal to the filter non-ideality. Our results give guidelines for design of efficient and highly selective flame-radiation-based fire detection sensors.

关键词： Flame detection Spectral radiation Optical filter Flame emission spectra Optimization pattern search algorithm

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Reduced nonlinear unknown inputs observer using mean value theorem and patternsearch algorithm

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AUTOMATICA 2020年 112卷

作者： Ben Messaoud, Ramzi Ctr Rech & Technol Energie Lab Nanomat & Syst Energies Renouvelables BP 95 Hammam Lif 2050 Tunisia

This paper is devoted to reduced order of unknown inputs observer design. A new structure is proposed, and it includes the dynamics of the estimation error and the uncertain parameters beta integrated into the mean value theorem. The pattern search algorithm will be used for the determination of beta parameters and the observer design. The stability study relies on the use of the quadratic Lyapunov functions. The observer gain is systematically determined by using an analytical method. A second method will be proposed for the gain determination, and it is based on the LMI technical and the polytopic transformation. The case of outputs affected by the disturbances is also studied. Finally, a numerical example is provided to illustrate the performance of the proposed approach. (C) 2019 Elsevier Ltd. All rights reserved.

关键词： pattern search algorithm Nonlinear reduced observer Nonlinear system Mean value theorem State estimation

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Frequency and pattern reconfigurable rectangular patch antenna using single PIN diode

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AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS 2020年 125卷 153370-153370页

作者： Palsokar, Anuradha A. Lahudkar, S. L. Rajarshi Shahu Coll Engn Pune Maharashtra India Imperial Coll Engn & Res Pune Maharashtra India

The paper presents the design of a frequency and pattern reconfigurable rectangular patch antenna using a single PIN diode switch. The use of single PIN diode reduces the complexity of the biasing network required for the diode. The proposed antenna can work in two different modes and resonates at 2.47 GHz, 3.8 GHz, and 5.36 GHz with the capability to change the radiation pattern. In this design biasing lines required for biasing of the diode are placed away from the radiating structure and the pattern search algorithm is used for the optimization of antenna feed for achieving impedance matching. These are the two improvisations made in the presented design as compared to the existing designs in literature. (C) 2020 Elsevier GmbH. All rights reserved.

关键词： Frequency reconfigurable antenna Rectangular patch antenna pattern reconfigurable antenna pattern search algorithm PIN diode

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Novel computing paradigms for parameter estimation in power signal models

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NEURAL COMPUTING & APPLICATIONS 2020年第10期32卷 6253-6282页

作者： Mehmood, Ammara Chaudhary, Naveed Ishtiaq Zameer, Aneela Raja, Muhammad Asif Zahoor Pakistan Inst Engn & Appl Sci Dept Elect Engn Islamabad Pakistan Int Islamic Univ Dept Elect Engn Islamabad Pakistan Pakistan Inst Engn & Appl Sci Dept Comp & Informat Sci Islamabad Pakistan COMSATS Inst Informat Technol Dept Elect Engn Attock Pakistan

The strength of evolutionary computational heuristic paradigms is exploited for parameter estimation of power signal modeling problems by incorporating differential evolution (DE), genetic algorithms (GAs) and pattern search (PS) methodologies. The objective function of power signal harmonics is constructed by utilizing the power of approximation theory in mean squared error sense. The stiff optimization task of signal harmonics is performed with heuristic solvers DE, GAs and PS that provide efficacy, fast convergence rate and avoid getting trapped in local minima. Statistics reveal that DE outperforms its counterparts in terms of accuracy, robustness and complexity measures.

关键词： Power signals Parameter estimation Differential evolution Genetic algorithm pattern search algorithm Evolutionary computing

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Determination of particle size distribution by light extinction method using improved pattern search algorithm with Tikhonov smoothing functional

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JOURNAL OF MODERN OPTICS 2012年第21期59卷 1829-1840页

作者： Wang, Li Sun, Xiaogang Xing, Jian Harbin Inst Technol Dept Automat Measurement & Control Engn Harbin 150001 Peoples R China Harbin Engn Univ Coll Sci Harbin 150001 Peoples R China

An inversion technique which combines the pattern search algorithm with the Tikhonov smoothing functional for retrieval of particle size distribution (PSD) by light extinction method is proposed. In the unparameterized shape-independent model, we first transform the PSD inversion problem into an optimization problem, with the Tikhonov smoothing functional employed to model the objective function. The optimization problem is then solved by the pattern search algorithm. To ensure good convergence rate and accuracy of the whole retrieval, a competitive strategy for determining the initial point of the pattern search algorithm is also designed. The accuracy and limitations of the proposed technique are tested by the inversion results of synthetic and real standard polystyrene particles immersed in water. In addition, the issues about the objective function and computation time are further discussed. Both simulation and experimental results show that the technique can be successfully applied to retrieve the PSD with high reliability and stability in the presence of random noise. Compared with the PhillipsTwomey method and genetic algorithm, the proposed technique has certain advantages in terms of reaching a more accurate and steady optimal solution with less computational effort, thus making this technique more suitable for quick and accurate measurement of PSD.

关键词： light extinction method particle size distribution retrieval pattern search algorithm inversion method

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Dynamic pressure based mid-course guidance scheme for hypersonic boost-glide vehicle

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART G-JOURNAL OF AEROSPACE ENGINEERING 2019年第9期233卷 3211-3222页

作者： Kumar, G. Naresh Sarkar, A. K. Talole, S. E. Def Res & Dev Lab Hyderabad India Def Inst Adv Technol Dept Aerosp Engn Pune 411025 Maharashtra India

In this study, a guidance scheme for an aerodynamically controlled hypersonic boost-glide class of flight vehicle is proposed. In this work, optimum glide dynamic pressure corresponding to maximum L/D throughout the flight is calculated and a mid-course guidance law formulation to track the dynamic pressure while suppressing phugoid oscillations is proposed for real-time flight trajectory shaping. Efficacy of the proposed guidance scheme has been demonstrated through simulation studies. Robustness analysis on the proposed guidance algorithm is carried out using Monte Carlo technique. Lastly, a pattern search algorithm-based offline generated maximum L/D optimal trajectory existing in literature, which meets minimum dynamic pressure, maximum airframe skin temperature, as well as other in-flight and terminal constraints is used as reference trajectory to evaluate the performance of the proposed guidance scheme.

关键词： Dynamic pressure hypersonic boost-glide vehicle mid-course guidance Monte Carlo pattern search algorithm skin temperature stability

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Optimized Semi-implicit Methods for Modeling Cardiac Propagation

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APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY JOURNAL 2019年第10期34卷 1616-1619页

作者： Khan, Riasat Ng, Kwong T. North South Univ Dept Elect & Comp Engn Dhaka Bangladesh New Mexico State Univ Dept Elect & Comp Engn Las Cruces NM 88003 USA

Computer simulation of cardiac electrophysiology is now considered a powerful tool for exploring the causes of cardiac arrhythmias Cardiac electric propagation has been studied using the monodomain model to describe wave propagation of action potential in the heart. The governing nonlinear reaction-diffusion partial differential equation is solved with the semi-implicit (implicit-explicit) method that does not have the stability limit of the explicit time-stepping scheme. Both first order and second order semi-implicit techniques for temporal discretization are considered in this paper. Second order finite difference technique is used to discretize the spatial derivatives. An explicit finite difference scheme with 512X512 nodes and 0.1 us time step is used as the benchmark for error calculation. APPSPACK, a parallel pattern search optimization software, is used to obtain the optimal semi-implicit parameters that give the lowest root-meansquare error. Results are presented for the semi-implicit techniques with or without the operator split or protective zone method. They demonstrate that the optimized second order semi-implicit method gives the best overall performance.

关键词： Derivative-free optimization method monodomain model operator split method pattern search algorithm semi-implicit scheme

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Thermodynamic analysis and performance optimization of transcritical power cycles using CO₂-based binary zeotropic mixtures as working fluids for geothermal power plants

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APPLIED THERMAL ENGINEERING 2017年 115卷 292-304页

作者： Wu, Chuang Wang, Shun-sen Jiang, Xihang Li, Jun Xi An Jiao Tong Univ Inst Turbomachinery State Key Lab Multiphase Flow Power Engn Shaanxi Engn Lab Turbomachinery & Power Equipment 28 Xianning West Rd Xian 710049 PR Peoples R China

Transcritical power cycles (TPCs) using CO2-based binary zeotropic mixtures for the conversion of low-grade geothermal water at 100-150 degrees C into power are presented and analyzed when cooling water temperature (T-cw) is 10-30 degrees C in this paper. 6 refrigerants are selected as the additives into CO2 according to 2 criteria. Performances of TPCs with 6 selected CO2-based mixtures are optimized by pattern search algorithm (PSA). Thermodynamic and economic analyses are conducted. The results reveal that R161/CO2 is the best fluid for a TPC in terms of both thermal performance and economic performance while R290/CO2 might be an unsuitable working fluid in TPC due to its lower thermal performance. When T-cw, = 10-20 degrees C, a TPC using R161/CO2 at X-R161 = 0.7 can increase net power output by 14.43-50.46% and decrease cost per net power by 27.96-48.72% compared with a TPC using CO2. The selected CO2-based mixtures can reduce CPP of a TPC compared with CO2 although more heat transfer area is required. Meanwhile, the CO2-based mixtures can decrease the high operating pressure, and enlarge the condensing temperature range compared with CO2. In addition, the CO2-based mixtures except R161/CO2 and R152a/CO2 are not recommended for a TPC when T-cw is low. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Transcritical power cycle Geothermal water CO2-based binary zeotropic mixtures Economic analysis pattern search algorithm

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Optimal setting of directional over-current relays in distribution networks considering transient stability

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INTERNATIONAL TRANSACTIONS ON ELECTRICAL ENERGY SYSTEMS 2016年第1期26卷 122-133页

作者： Mosavi, S. Mohammad Ali Kejani, Tohid Akbari Javadi, Hamid Shahid Beheshti Univ AC Fac Elect Engn Tehran Iran PSEEZ Asaluyeh Iran Islamic Azad Univ Islamshahr Branch Dept Elect Engn Islamshahr Iran Shahid Beheshti Univ AC Islamshahr Branch Fac Elect Engn Tehran Iran

Because of the nonlinear characteristic of directional over-current relays (DOCR), optimal setting and coordination of DOCRs are a complicated task in an interconnected distributed network. These relays are usually coordinated without considering constraints of power system transient stability. In this paper, we present a novel methodology for relay coordination considering transient stability as a constraint in optimization problem of over-current relays setting. The relays are set and coordinated based on the obtained results. For this purpose, an appropriate objective function is proposed, and then a two-phase procedure is used in order to consider relays constraints. pattern search (PS) algorithm is employed to solve the problem under MATLAB software. Results of the proposed approach on a typical distributed network are shown and discussed. These results signify the effectiveness of the presented method. Copyright (c) 2015 John Wiley & Sons, Ltd.

关键词： directional over-current relay optimal relay setting pattern search algorithm relay coordination transient stability

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