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Load Forecasting of District Heating System Based on Improved Fb-Prophet Model

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SSRN 2022年

作者： Shakeel, Asim Chong, Daotong Wang, Jinshi State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shaanxi Xi'An710049 China

Accurate load forecasting of district heating networks (DHN) is an essential guide to guaranteeing effective energy production, distribution, and rational utilization. Artificial neural networks have been extensively applied to heating energy prediction in DHN. An improved FB-Prophet model with additional positional encoding layers has been developed to forecast the DHN heat consumption. The accuracy of univariate and multivariate FB-prophet models is evaluated;this paper also investigates how training data affects the accuracy and robustness of improved FB-prophet model. Results revealed that the accuracy of the improved FB-Prophet model increases as the amount of training data increases;it is also observed that there exists a turning point after which robustness starts to decrease. To explore the performance of the improved FB-Prophet model in heating load forecasting tasks, another seven machine learning models, namely FB-Prophet, DeepVAR, long-short term memory (LSTM), extreme gradient boosting (XGBoost), multilayer perceptron (MLP), recurrent neural network (RNN), and support vector regression (SVR) are used for comparison. The historical heating load, outside temperature, relative humidity, speed of wind, direction of wind, and weather type (sunny, overcast, rainy) of a DHN in Serbia are utilized as the key parameters to extensively investigate the effectiveness of the improved FB-Prophet model. The prediction outcomes of all the models were analyzed thoroughly. The results indicated that the improved FB-Prophet model can generate the most precise and consistent predictions and it showed better results for sparse and noisy data of DHN. The prediction curve is fitted to the trend of hourly DHN consumption change, which can play an effective guiding function in the distribution of heat. © 2022, The Authors. All rights reserved.

关键词： Forecasting

Experimental Study on Non-Isothermal Mixing Characteristics of Water in T-Junction

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Experimental Study on Non-Isothermal Mixing Characteristics ...

China Instrument and Control Society (ACCIS), Academic Conference of

作者： Shuhan Liu Wencang Guo Xianliang Lei Zhaojun Yuan Shuqi Meng Desheng Jin State Key Laboratory of Multiphase Flow Engineering Xi'an Jiaotong University Xian China China Nuclear Power Technology Research Institute Co. Ltd. Shen Zhen Guangdong China

ISBN: (数字)9798350350326

ISBN: (纸本)9798350350333

T-junction is an essential component in piping system of various thermal systems. When hot and cold fluid mixing in the T-junction, several compound mechanisms (like turbulent mixing, turbulent penetration, fluid stratification) make the mixing characteristics more complex. To clearly reveal such mixing mechanism with non-isothermal fluids, an experimental study was conducted with Ultrasound Doppler Velocimetry (UDV) and fast-response thermocouples bundle. The results show that the local velocity uncertainty of the UDV is within 10%, the uncertainty of the thermocouple bundle is 0.5°C, and the response time is 66.7 ms. After verification, the mixing characteristics between the main and branch pipe under different momentum ratios and temperature differences were discussed. It is shown that as the momentum ratio decreases, the location of the most intense radial temperature fluctuations and velocity fluctuations shifts towards the lower wall. At the same time, the peak flow rate in the cross-section increases by 35.7% and the main branch fluid mixing is more homogeneous. As the temperature difference increases, the thermal stratification is more pronounced and the velocity fluctuation peak moves towards the upper wall of the pipe.

关键词： Temperature measurement Temperature distribution Fluctuations Fluids Uncertainty Measurement uncertainty Thermocouples Distance measurement Velocity measurement Voltage control

Experimental Study on Slagging and Fouling Behaviors During Oxy-Fuel Combustion of Zhundong Coal Using a Drop Tube Furnace 9th

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Experimental Study on Slagging and Fouling Behaviors During ...

9th International Symposium on Coal Combustion, ISCC 2019

作者： Zhao, Lei Wang, Chang’an Hu, Yueyi Sun, Ruijin Tang, Guantao Guo, Jin Jiang, Zhiming Du, Yongbo Che, Defu State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China Guangdong Institute of Special Equipment Inspection and Research Foshan528251 China Shunde Institute of Inspection Guangdong Institute of Special Equipment Inspection and Research Foshan528251 China

ISBN: (纸本)9789811616563

Zhundong coal featuring high content of alkali metals induces severe slagging and fouling problems during its utilization in utility boilers. Oxy-fuel combustion technology can achieve a large amount of CO2 capture and reduce the NOx emission. Unfortunately, in-depth investigation has been seldom carried out on the process of ash deposition and slagging of high-alkali coal during oxy-fuel combustion. In the present study, the oxy-fuel combustion of high-alkali coals were experimentally studied using a non-cooled sampling probe in a drop tube furnace. The fouling and slagging mechanisms were investigated in various atmospheres, temperatures and different O2 concentrations. In addition, the slag samples were characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) coupled with Energy Dispersive X-ray Spectrometer (EDS). Experimental results indicated that under air and oxy-fuel conditions with the same O2 content, the types of elements and minerals were almost the same. With the temperature increased, the adhesion between the slag samples was strengthened and the pore structure slag was increased. The degree of slag melting and sintering was aggravated at the temperature of 1200 °C and the slag structure was complicated. As the oxygen concentration was increased, some of the spherical particles had completely melted on the surface of the massive ash, resulting in an uneven surface. The present work can provide new insights into the slagging and ash deposition of Zhundong high-alkali coal during oxy-fuel combustion. © 2022, Tsinghua University Press.

关键词： Coal

An Experimental Study on Ash Deposition Problem of Low-Low Temperature Flue Gas System 9th

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An Experimental Study on Ash Deposition Problem of Low-Low T...

9th International Symposium on Coal Combustion, ISCC 2019

作者： Yan, Yu Jiang, Jiahao Guo, Jin Li, Yuesheng Deng, Lei Che, Defu State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China Guangdong Institue of Special Equipment Inspection and Research Foshan528251 China Guangdong Institue of Special Equipment Inspection and Research Shunde Institue of Inspection Foshan528300 China

ISBN: (纸本)9789811616563

In order to achieve the ultra-clean emission standards, many power plants in China have completed the installation of low-low temperature flue gas system. However, during the operation of this system, many problems have emerged, such as the ash deposition problem in the heat exchanger and dry ESP (electrostatic precipitator). In this paper, the fixed adsorption system and entrained flow experimental system were built to study the ash deposition characteristics in low-low temperature flue gas system under different temperatures and particle sizes. The repose angle was measured to evaluate the flowability and adhesion capacity of ash particles. The results show that as the increase of adsorption time, the particle size increased gradually, and the agglomeration effect is attenuated after the particles have reached adsorption saturation. The time at which the ash particles began to agglomerate with each other was defined as the agglomeration threshold. As the adsorption temperature decreased, the particle size growth rate increased. The smaller the size of ash particles, the more significant the agglomeration effect. Large particles were easy to adsorb small particles, but the agglomeration effect between large particles was weak. In addition, in the initial stage of particle agglomeration, it was mainly included the adhesion between smaller particles and the adhesion of smaller particles on the surface of large particles. The followability of the ash particles was greatly reduced after the adsorption and agglomeration process. The repose angle of the ash particles increased as the temperature of the flue gas decreased. The smaller the particle size, the larger the repose angle changes, and the more pronounced the repose angle is influenced by the adsorption temperature. The flue gas temperature cannot be blindly dropped in pursuit of high sulfur oxide removal efficiency and dust removal efficiency. © 2022, Tsinghua University Press.

关键词： Particle size

A Gpu-Accelerated Multi-Resolution Lsmps Method for multiphase flows Simulation with Gas-Liquid Phase Transition

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SSRN 2024年

作者： Cao, Sheng Ren, Qianyong Wang, Wenpeng Zhang, Bin Shan, Jianqiang School of Nuclear Science and Technology Xi’an Jiaotong University Shaanxi Xi’an710049 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shaanxi Xi’an710049 China

The meshless Lagrangian method (particle method) demonstrates significant advantages in simulating multiphase flows with highly dynamic phase interfaces and has been widely applied in research areas such as ocean engineering, nuclear engineering, and aerospace engineering. The least squares moving particle semi-implicit (LSMPS) method theoretically attains high-order accuracy, significantly enhancing the precision and stability of simulations. However, compared to traditional Eulerian methods, its numerical discretization is more complex and computationally intensive, which limits its applicability in large-scale simulations. To mitigate these challenges, a multi-resolution particle model is implemented to reduce computational costs, and algorithmic improvements and optimizations enable GPU-based parallel processing, significantly boosting computational efficiency. Building on this foundation, a high-precision surface particle detection algorithm and a stable gas-liquid phase transition model are developed. The phase transition model integrates the volume change resulting from phase transition as a source term in the pressure Poisson equation. Benchmark tests of single bubble rising in liquid, Rayleigh-Taylor instability, and two-dimensional horizontal film boiling were conducted to validate the accuracy and efficiency of the GPU- accelerated multi-resolution LSMPS method for simulating multiphase flows, thereby promoting the application of the LSMPS method in both scientific research and practical engineering. © 2024, The Authors. All rights reserved.

关键词： Poisson equation

Preparation, improvement, and application of metal–organic framework-based sensing materials for gas leakage and emission: A review

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Nano Materials Science 2025年

作者： Liu, Manyi Wang, Liang Ren, Shan Bai, Bofeng Chai, Shouning He, Chi Zheng, Chunli Yin, Xitao Li, Fengguang College of Materials Science and Engineering Chongqing University Chongqing400044 China State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'an710049 China School of Physics and Optoelectronic Engineering Ludong University Yantai264000 China School of Materials Science and Engineering Hubei University of Automotive Technology Shiyan442002 China

Industrial gas leaks and flue gas emissions pose significant threats to the safety of industrial operations and the atmospheric ecological environment. Traditional gas sensing materials often struggle to meet the challenges posed by complex industrial environments. Recently, metal-organic framework (MOF)-based gas sensing materials have garnered significant attention in industrial gas detection due to their high sensitivity, selectivity, and tunable properties. The exponential increase in related publications highlights the growing research interest in this field. This paper presents a comprehensive review of the advantages of various types of metal-organic frameworks and their derivatives for detecting industrial gas leaks and flue gas emissions, alongside an introduction of representative MOF synthesis methods. Furthermore, the primary sensing mechanisms of MOF-based gas sensing materials and strategies for enhancing the sensing performance are summarized. The current state of MOF-based gas sensing materials in industrial gas detection is also discussed. Finally, the potential limitations, existing challenges, and future directions of MOF-based industrial gas sensing materials are systematically analyzed, with suggestions for addressing these challenges to advance industrial gas detection technologies. © 2025 Chongqing University

关键词： Application Improvement Industrial gas detection MOF-Based sensing materials Preparation

Novel Fast Predesign Methodology of Centrifugal Compressor Used for Pemfcs Based on 1d Loss Mechanism and Interpretable Machine Learning Models

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SSRN 2024年

作者： Chen, Zhikai Sun, Jieshuai Chen, Ziying Spence, Stephen Peng, Xueyuan Feng, Jianmei School of Energy and Power Engineering Xi'an Jiaotong University Xi'An710049 China School of Mechanical Manufacturing and Biomedical Engineering Trinity College Dublin Dublin 2 Ireland State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xi'An710049 China

The significant challenge of balancing accuracy, time, and cost has consistently compelled designers to develop more efficient and economical predesign methods. To tackle this issue, a novel predesign method amalgamating one-dimensional (1D) loss model with gradient boosting decision tree (GBDT) model has been proposed. A high-precision 1D loss model was developed and experimentally tested for rapid performance assessment. Furthermore, two machine learning models, named Extreme Gradient Boosting (XGBoost) and Light Gradient Boosting Machine (LightGBM), were trained, and compared to construct surrogate models. Hyperparameter optimization was executed utilizing a Bayesian algorithm to identify the optimal hyperparameter set. Additionally, the Sobol sensitivity analysis and Shapley Additive Explanations (SHAP) based interpretability were used to explore the paramount factors affecting the model's outputs and the interactions among the sensitive parameters. The findings underscore that the blade outlet angle, impeller outlet diameter, impeller outlet width, inlet shroud diameter, and blade inlet angle(shroud) are the most five important parameters influencing the model's indexes. Some beneficial design guidelines are distilled from their feature importance and interactions. and The implement of new design yields powerful evidence for the developed prior knowledge with an increase of 2.5830% in isentropic efficiency and a reduction of 1.5202% in power consumption. © 2024, The Authors. All rights reserved.

关键词： Sensitivity analysis

Effect of Chemical Composition on Adsorption and Agglomeration Characteristics of Ash Particles After Sulfuric Acid Adsorption 9th

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Effect of Chemical Composition on Adsorption and Agglomerati...

9th International Symposium on Coal Combustion, ISCC 2019

作者： Jiang, Jiahao Yan, Yu Guo, Jin Li, Yuesheng Deng, Lei Che, Defu State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China Guangdong Institue of Special Equipment Inspection and Research Foshan528251 China Guangdong Institue of Special Equipment Inspection and Research Shunde Institue of Inspection Foshan528300 China

ISBN: (纸本)9789811616563

The low-low temperature electrostatic precipitator has been applied to enhance the efficiency of power plants. In this paper, the influences of chemical constitutions on the adsorption properties of particulate matters with vitriolic acid and the agglomeration after adsorption are researched. Experiments are conducted on a one-dimensional adsorption system, which simulates the working environment of low-low-temperature electrostatic precipitator. The consequences display that the agglomeration between particulate matters in scanning electron microscopy are loose pellets agglomeration together, adhesion of loose pellets to massive particles, and massive particles agglomeration together. For Na and K, the amounts of elements added have little effect on the adsorption of the sulfuric acid by ash particles. For Mg, Fe, and Ca, when the oxide is used as an additive, the adsorption capacity of ash samples to the vitriolic acid was enhanced and the agglomeration phenomenon of the ash granules was more remarkable with increasing elements amounts. In addition, the change of Mg has great impact on vitriolic acid adsorption and granules agglomeration. © 2022, Tsinghua University Press.

关键词： Adsorption

Chromium Promoted the Efficient and Stable Catalytic Degradation of Propane Over Pt/Hzsm-5 Catalyst: Optimization and Reaction Mechanism

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SSRN 2025年

作者： Jian, Yanfei Xu, He Wang, Yao Wang, Jingjing Xia, Lianghui Liu, Yujie Yu, Yanke He, Chi State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Shaanxi Xi'An710049 China National Engineering Laboratory for VOCs Pollution Control Material and Technology University of Chinese Academy of Sciences Beijing101408 China Yunnan University China

Light alkanes are a class of ubiquitous volatile organic compounds (VOCs), which bring great environmental hazards and health risks. However, low-temperature degradation of light alkanes is still a great challenge. Herein, a series of Pt/HZSM-5 catalysts without/with additives of Cr were fabricated. Catalytic performance of the catalyst for C3H8 low temperature combustion was investigated. It was found that Cr element had a significant effect on the activity of Pt/HZSM-5. Pt/Cr1/HZSM-5 performed the best activity for C3H8, excellent high temperature stability and water resistance. Characterization results of catalysts indicated that the introduction of Cr element could fix Pt site to promote the dispersion of Pt on the support. Moreover, the interaction between Cr and Pt produced more active Pt species, surface active lattice oxygen and acidic sites, which could promote the activation of C-H bonds in C3H8. Theoretical calculations showed that the interface between Pt and Cr had stronger adsorption for O2 and C3H8, which could accelerate propane oxidation. In this study, the effect of transition metal elements on the promotion of noble metal catalysts in the low-temperature degradation of light alkanes was discussed in depth, and it provided a reference for the design of efficient noble metal molecular sieve catalysts. © 2025, The Authors. All rights reserved.

关键词： Molecular sieves