Table of Content

25 July 2022, Volume 50 Issue 7

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Contents



2022, 50(7):  0-0. 

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Architecture & Civil Engineering

Axial Compression Behavior of High-Strength Circular Steel Tube Confined High-Strength Steel Reinforced Concrete Short Columns



KANG Lan, CHEN Zonglin, LIN Yiwei

2022, 50(7):  1-12.  doi:10.12141/j.issn.1000-565X.210463

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This paper carried out axial compression tests on nine circular steel tube confined steel reinforced (CSTCSR) concrete short columns, one circular steel tube confined (CSTC) concrete short column and one circular steel tube column filled with steel-reinforced concrete. The main purpose of this research is to study the influences of yield strength of steel tube and shape steel, diameter-thickness ratio of steel tube, concrete strength, inner surface treatment method of high-strength steel tube and restraint mode on the failure mode, strain response, axial compression bearing capacity and ductility of CSTCSR concrete short column. The results show that the failure mode of high-strength circular steel tube confined high-strength steel reinforced (HCSTCHSR) concrete short column is overall shear failure, and there is no obvious local buckling on the surface of high-strength steel tube, and the development of oblique cracks of concrete is effectively restricted by the embedded high-strength shape steel. For CSTCSR concrete short column, the axial compression bearing capacity ratio and ductility coefficient of this column with high-strength steel tube and high-strength shape steel are increased from 1.37 to 1.49 and from 2.22 to 3.25, respectively, compared with those of CSTCSR concrete short column using ordinary-strength steel tube and ordinary-strength shape steel. It is concluded that the HCSTCHSR concrete short column has more excellent axial bearing capacity and ductility, and high-strength steel using in such column can be fully utilized. On the basis of “technical standard for steel tube confined concrete structures” (JGJ/T471—2019) and the results of parametric analysis in this study, a modified formula for axial bearing capacity of HCSTCHSR concrete short column was proposed by using the existing confined concrete’s constitutive model to provide scientific basis and data support for practical engineering application.

Multi-objective Optimization of Flat Skylights in the Elevated Railway Station



JIANG Tao, LU Zhou

2022, 50(7):  13-24.  doi:10.12141/j.issn.1000-565X.210631

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Elevated railway stations are usually large-span buildings and require skylights. Traditional skylight design methods have difficulties in solving the multi-objective problem of complex requirements in lighting and energy-saving. In order to realize the multi-objective optimization of the flat skylight of the high-speed railway station, based on the pre-design parameter settings of the flat skylight of the elevated high-speed railway station, this paper constructed a set of genetic algorithm-based multi-objective optimization methods using Rhino and Grasshopper platforms, building performance simulation tool called Ladybug, and multi-objective optimization tool called Octopus. Multi-objective optimization method for flat skylight goes through the steps of determining variables, determining optimization objectives, building models and programming, using Rhino and Grasshopper to build a simplified parametric model, importing the Ladybug tool for performance analysis, and using Octopus tool to carry out iterative multi-objective optimization according to the analysis results. The optimization process can automatically change and simulate the parameterized part of the model, and record and compare the results of each change and simulation. And finally, it finds out the parameters that best meet the set multiple objectives. Returning the parameters to the parametric model can yield the optimal model and the corresponding building performance simulation results. Furthermore, an empirical analysis was carried out by taking Guangzhou Baiyun Station as an example. According to the requirements of the main lighting standards at home and abroad, the study first set the daylighting factor and the daylighting uniformity up to the standard, the useful daylighting illuminance as significant as possible, the possibility of glare occurrence as small as possible, and the solar radiation as small as possible as the target system. Then it used the method for multi-objective optimization. The results show that compared with the original scheme, the final scheme meets the basic standard of daylighting factor and has better lighting uniformity, useful daylighting illuminance, glare occurrence possibility, and solar radiation under the lighting intensity conditions. The proposed method has a wide range of application scenarios and more flexibility and can provide references for related research.

Design of an Innovative Eddy Current Replaceable Coupling Beam and Its Numerical Analysis



GONG Nan, LI Peizhen, HE Xuming

2022, 50(7):  25-34.  doi:10.12141/j.issn.1000-565X.210665

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This paper carried out a detailed study on the damping characteristics of the eddy current coupling beam damper, which can start to dissipate energy under small deformation of the replaceable coupling beam. Based on the analysis of magnetic circuit theory, the study proposed the optimal arrangement of permanent magnet pole in eddy current damper. In other words, the permanent magnet poles parallel to the direction of conductor motion were arranged alternately, and the permanent magnet poles perpendicular to the direction of conductor motion were arranged in the same direction. In view of this, two kinds of eddy current dampers were designed, one of which is the plate eddy current damper with the conductor plate moving straight in the magnetic field and the other is the rotary eddy current damper with the gear-rack mechanism to amplify the rotation speed of the conductor plate in the magnetic field. Two kinds of eddy current dampers were used in the replaceable coupling beam, and the finite element simulation of the new eddy current coupling beam damper installed on the replaceable coupling beam was carried out, which revealed the nonlinear mechanical behavior of eddy current damping. It shows that the damping coefficient and stiffness coefficient are strongly related to the frequency. The higher the loading frequency, the lower the energy consumption efficiency and the higher the dynamic stiffness of the structure. So, the eddy current damper is more suitable for low frequency working conditions, and at this time, the damping coefficient of the eddy current damper is large, the energy consumption efficiency is high, and the stiffness coefficient is small, which basically does not change the natural vibration characteristics of the structure. Therefore, it is of great value in real-world application.

Creep Behavior of Reinforced and Unreinforced Recycled Lump/Aggregate Concrete



WU Bo, CHEN Zhaonan, WANG Hui

2022, 50(7):  35-42.  doi:10.12141/j.issn.1000-565X.220046

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Compressive creep tests on thirty-seven recycled lump/aggregate concrete (RLAC) specimens were carried out to reveal the creep behavior of RLAC by taking the replacement ratio of demolished concrete lumps (DCLs), replacement ratio of recycled coarse aggregates (RCAs), replacement ratio of recycled sand rooted from alluvial-proluvial (A-P) soil, stress level and reinforcement ratio as parameters. The results show that the specific creep of reinforced/unreinforced RLAC is greater than that of reinforced/unreinforced recycled aggregate concrete (RAC). The increase rate of RLAC is 10.1% when unreinforced and the increase rate is 13.4% and 11.5% when the reinforcement ratio is 1.16% and 1.57%, respectively As the replacement ratio of RCAs in new concrete increased from 30% to 50%, the specific creep of reinforced/unreinforced RLAC increased by 7.4% and 11.4% respectively; when the fine aggregate (i.e., river sand) of new concrete is completely replaced by the recycled sand from A-P soil, the creep behavior of reinforced/unreinforced RLAC shows almost no change, but both of the shrinkage deformation decreased. As the reinforcement ratio increases from 1.16% to 1.57%, the specific creep of RLAC and RAC decrease by 5.0% and 6.6%, respectively. Reinforcement reduces the shrinkage deformation of RAC and RLAC, and the reduction grows with the increase of reinforcement ratio. As the replacement ratio of RCAs in new concrete increased from 30% to 50%, the elastic modulus of RLAC have little change and it is also almost free from the impact of replacing the fine aggregate (i.e., river sand) of new concrete with the recycled sand from A-P soil; and when the stress level is less than 0.4, the specific creep of RLAC is nearly deemed as irrelevant to the stress level.

High-Accuracy and Non-iteration Methods for Control Tension of Parallel-Strand Stay Cables



YU Xianbin, WANG Ronghui, CHEN Shanting, et al

2022, 50(7):  43-55.  doi:10.12141/j.issn.1000-565X.210730

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In order to obtain the high-accuracy solution for control tension of each strand of stay-cables during construction, this paper studied the nonlinear relationships among the parameters describing the static state of cables and proposed a high-accuracy and non-iteration solving method for control tension of each steel strand. Based on the exact solution of the catenary of the cable shape, the high-precision and approximate solution of the stress-free length of the cable was solved by the Taylor expansion method. Based on the two basic principles of forward assembly analysis and equivalent tensioning method, the equivalent static state of steel strands during the construction process was obtained by recursive calculation when different steel strands were tensioned. The high-precision solution for the control tension of each steel strand was solved by approximating the unstressed cable length, the equivalent cross-sectional area and the projected length of the diagonal cable.Taking the stay-cables of the main bridge of the Honghe Bridge (a composite girder cable-stayed bridge with a main span of 500 meters) in Zhuhai city, the Jitimen Bridge (a prestressed concrete cable-stayed bridge with a main span of 210 meters) in Zhuhai city and cables mentioned in two literatures as examples, the error between the approximate solution of the method in this study and the exact solution of the catenary of iterative solution was calculated. The results show that the calculated error of the stress-free cable length between the method proposed in this paper and the catenary solution is less than 0.002%, and the tension error of each strand is less than 2%, which fully meet the accuracy requirements of construction. The method presented in this paper has the advantages of high precision and low calculation cost, so it has a high value of popularization and application.

Traffic & Transportation Engineering

Methods of Determining the Range of Non-motorized Travel Influence Area Under the Concept of “Metro Transit Micro-center”



CHEN Tingzhao, CHEN Yanyan, WANG Zili, et al

2022, 50(7):  56-65.  doi:10.12141/j.issn.1000-565X.210651

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In response to the concept of land-use integration and creating micro-center around metro station in Beijing, this study extracted 23 quantitative indicators from public passenger flow, road network design, population density and land diversity to quantitatively analyze the built environment and travel characteristics of the non-motorized influence area based on multi-source big data. The connection characteristics of shared bicycles were taken into particular consideration. In order to compensate for the shortcomings of determining the influence range of metro stations by the traveler’s walking time, a classification model incorporating principal component analysis and K-means clustering was proposed to define the non-motorized influence area. Taking Beijing as an example, the study divided the metro stations into 4 clusters: inefficient connection-weak connectivity-residence oriented, efficient connection-high connectivity-balanced, efficient connection-weak connectivity-mixed, and efficient connection-high connectivity-work oriented. In order to verify the rationality of the clustering, the spatial auto-correlation was used to judge the spatial dependence of indicators. The results show that the spatial distributions of clusters 1, 3 and 4 do not differ significantly from the random model, while cluster 2 efficient connection-high connectivity-balanced stations has auto-correlation characteristics in space. Finally, based on the clustering results, the non-motorized influence areas of the metro stations were delineated as 2 000, 1 600, 1 600, and 1 700 m, respectively. The clarification of the non-motorized influence range of different metro station types can help urban planners determine the scope of micro-center construction and also lay the foundation for transport-oriented development of urban in the future.

Cooperative Lane Change Decision-Making Model of Bottleneck Emergency Section in Weaving Area Based on Social Force



QIN Yaqin, QIAN Zhengfu, XIE Jiming, et al

2022, 50(7):  66-75.  doi:10.12141/j.issn.1000-565X.210787

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To describe the lane-changing decision mechanism of vehicles in the bottleneck section of weaving area and provide a lane-changing decision model in the emergency environment, this paper constructed a collaborative lane-changing decision model of vehicles facing bottleneck section based on the micro-trajectory information of vehicles and the human traffic flow model of social force. This model can provide a lane-changing decision method for the sudden bottleneck environment of intelligent network connection. Firstly, based on the characteristics of lane-changing decision of vehicles in the sudden bottleneck section, the vehicle equivalent mass model was constructed to improve the social force model by considering the types of vehicles and drivers. On this basis, the factors driving vehicle lane-changing were described as automatic driving force, repulsive force among vehicles and repulsive force of obstacles, and the collaborative lane-changing decision model was constructed. Then, 832 microscopic trajectory data of lane change decisions were selected and divided into calibration set and verification set. The model was calibrated using genetic algorithm with acceleration as index and Manhattan distance as objective function. The validity of the calibration method was verified based on simulated data and measured data. Finally, this model was compared with the active lane changing decision model in lane changing direction identification, lane changing intention intensity and model prediction error. The results show that the success rate of lane change direction recognition of the proposed model is 92.6%, the output lane change intention intensity is basically consistent with the measured data, and the predicted RMSPE value decreases by 0.825 on average and RE value decreases by 1.379 on average, which are significantly better than those of the active lane change decision model. The research results can provide a theoretical basis for the identification of vehicle lane change intention in the bottleneck section of intelligent network environment and traffic management and control under emergencies.

Influence of the Combination Equilibrium of Horizontal and Crest Vertical Curves on Highway Safety



WANG Xiaofei, LI Siyu, CHEN Mi, et al

2022, 50(7):  76-84.  doi:10.12141/j.issn.1000-565X.210658

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To throughly analyze the quantitative relationship between the equilibrium of horizontal and vertical alignment combination and road safety, aiming at the “horizontal curve(HC)+crest vertical curve(CVC)” (referred to as HC-CVC) alignment combination, this study collected the road alignment (a total of 477 km), the traffic data and accident data from 2011 to 2018 of four interstate roads in Washington, D.C. as training data and test data. According to the characteristics of horizontal and vertical alignment combination, the paper suggested to consider the dislocation value, the horizontal curve radius, the vertical curve radius, the length of horizontal curve and the length of vertical curve as variables to characterize the equilibrium of horizontal and vertical alignment combination. Three machine learning models, namely, Decision Trees, Random Forests and Extremely Randomized Trees, were applied for model training to analyze the influence of HC-CVC combination on the accident rate per 100 000 000 vehicle kilometers. The prediction and fitting accuracy of Random Forests is the highest among all models. What’s more, sensitivity analysis and numerical analysis based on Random Forests model show that: when the horizontal curve radius is greater than 2.8 km or the vertical curve radius is greater than 58 km, the increase of horizontal and vertical curve radius has little impact on the road safety. At the same time, this paper also studied the correlation between variables and accident and suggested the value range of the variables when the horizontal curve radius is small. The research conclusions can provide reference for the subsequent quantitative optimization design and safety improvement of horizontal and vertical alignment combination.

Study on Crashworthiness of Hybrid Gradient Negative Poisson’s Ratio Structure Under Multi-conditions



MA Fangwu, WANG Qiang, MA Wenting, et al

2022, 50(7):  85-97.  doi:10.12141/j.issn.1000-565X.210696

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In order to meet the requirements of actual vehicles collision and improve the crashworthiness of vehicle energy absorbing components, this paper proposed a hybrid gradient negative Poisson’s ratio structure based on the bionic principle, and established a finite element model. At the same time, the test sample was made for axial compression test to verify the accuracy of the finite element model. Using LS-DYNA, the mixed gradient structures with nine different arrangement modes were simulated under different impact angles and impact speeds. The comparison results of comprehensive crashworthiness indexes show that the optimal arrangement mode under multiple working conditions is the combination of transverse negative gradient and longitudinal positive gradient. Compared with the uniform gradient structure, its comprehensive energy absorption is increased by 19.2%, energy absorption stability is improved by 30.6%, and the improvement is obvious. Through the comparative analysis of the deformation modes of hybrid gradient structures with different arrangement modes, it finds that a single transverse gradient can improve the energy absorption stability of the structure, while a single longitudinal gradient can improve the comprehensive energy absorption performance of the structure. Because of the reasonable material distribution, the optimal hybrid gradient structure takes into account the comprehensive energy absorption and energy absorption stability and explains the reason of the excellent comprehensive performance of the optimal arrangement from the internal mechanism, which is conducive to the engineering of the mixed gradient negative Poisson’s ratio structure.

Mortar Void Identification Based on the Improved LMD with Dynamic Moving Step



XIN Xin, REN Zunsong

2022, 50(7):  98-107.  doi:10.12141/j.issn.1000-565X.210673

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As an important component of the ballastless slab track, cement asphalt mortar is prone to void damage under the combined action of high-frequency train loads and temperature loads. The mortar void can be located quickly and accurately according to the change characteristics of wheelset accelerations. The vertical wheelset acceleration was decomposed into a series of product functions via local mean decomposition improved by adaptive dynamic moving step. Based on the change of kurtosis, the first product function that can best reflect the mortar void characteristics was selected, and its instantaneous energy and standardized instantaneous energy were calculated to enhance the mortar void feature. By analyzing whether there are outliers in the envelope functions of instantaneous energy and standardized instantaneous energy, whether the mortar is damaged can be determined. The results show that when the mortar void length is no more than 0.30 m, there is no outlier in envelop function of instantaneous energy at the mortar void position, resulting in “missing judgment”; and the envelop function of standard instantaneous energy has outliers both at the void and non-void position, resulting in “misjudgment”. When the mortar void length is no less than 0.65 m, the envelope functions of instantaneous energy and standardized instantaneous energy only have outliers at the mortar void position, which can be directly used to locate the mortar void position. Identifying mortar void through responses of vehicle structures can effectively alleviate the pressure of track damage detection and improve vehicle operation efficiency.

Commutation Failure Detection Based on Temporal Feature of AC Maximum Current on the Valve-Side



LI Xiaohua, YIN Shanshan, LI Jiewen, et al

2022, 50(7):  108-117.  doi:10.12141/j.issn.1000-565X.210810

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Commutation failure (CF) is common for the operation of HVDC transmission system, and it reflects the vulnerability of converter. The existing methods for judging CF are subject to influence of fault factors and control adjustments, resulting in the insufficient sensitivity of the methods. Accurate and reliable detection of CF is extremely important to control and protection. Therefore, the paper proposed a detection scheme for CF based on temporal feature of AC maximum current on the valve-side starting from detecting the valve conduction interval. Firstly, the characteristics of AC maximum current was constructed based on the ratio between the unilaterally polarity current of AC current on the converter terminal and the half of the maximum value of the three-phase AC current. Secondly, to reduce the impact of operating conditions, taking the current intersection of two commutating valves currents as the demarcation point, the virtual conducting state of the valve was constructed by using half of the amplitude of the characteristic quantity of AC maximum current, and the accumulated width was calculated by integrating it in a period to determine whether the virtual conducting state of the valve is abnormal.Then, the interlocking relationship between the lengthened and shortened virtual conduction width was used to determine the commutation failure during the commutation process. According to the analysis of power disturbance, fault transiency and the sampling step, the threshold for commutation failure was derived. The recommended threshold value is 1.3 millisecond. Finally, based on the PSCAD / EMTDC electromagnetic transient simulation and wave recorded data, the results show that the proposed detection method is reliable to detect commutation failure. Compared with the detection method based on differential current, the proposed method for detecting commutation failure is less affected by factors, such as operating conditions of AC and DC system, fault moment, and fault severity under different fault conditions. This proposed method can locate the valve of commutation failure and provides more margin for the adjustment of the control system.

Experiment Study of Capturing CO₂ from Pyrolysis Gases by Zr-Mg Modified Sorbents



TANG Yuting, CHEN Xiaobin, MA Xiaoqian

2022, 50(7):  118-125.  doi:10.12141/j.issn.1000-565X.210470

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With the development of economy and accelerated urbanization, the increasing production of municipal solid wastes brings great impact on people’s daily life and health. How to recycle, reduce and harmlessly treat solid wastes has become an urgent problem. The pyrolysis of municipal solid wastes is an effective way to solve the current “garbage siege” and resource shortage, but the high content of CO₂ in the pyrolysis gas will affect its subsequent combustion and utilization. Calcium-based sorbents are considered as one of the most promising CO₂ capture materials due to their wide source, low cost and high adsorption capacity. However, the adsorption performance of conventional calcium-based sorbents decays rapidly as the number of cycles increases. To address this problem, this study prepared modified calcium-based sorbents doped with metal Zr and Mg by co-precipitation method. The effects of doping ratios of Zr and Mg, carbonation temperature and calcination temperature on the modified calcium-based sorbents were obtained by fixed bed reactor. The experimental results show that the doping ratios of metal Mg and Zr should not be too high or too low, and the optimal doping ratio (the molar ratios of Ca, Mg and Zr) is 10∶1∶0.5. Because too low doping ratio will retard the sintering of the sorbent, while too high doping ratio will lead to the reduction of CaO content and active reaction sites on the surface of the sorbent. The sorbent with the doping ratio of 10∶1∶0.5 has the best adsorption performance when adsorbed at 700 °C and calcined at 900 °C, respectively, with an average carbonation conversion of 76.3% after ten cycles.When applying on product gas, the capture ratio of CO₂ reaches 83.8% with 10∶1∶0.5 doping ratio under 700 °C carbonation temperature.

Analysis of Operation Characteristics of Pulsating Heat Pipe Under the Condition of Non-uniform Heat Flux



ZHANG Dong, HOU Hongyi, LI Qingliang, et al

2022, 50(7):  126-135.  doi:10.12141/j.issn.1000-565X.210548

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To further explore the influence of different operating parameters on the heat transfer characteristics of pulsating heat pipe under the condition of non-uniform heat flux and broaden the application scenarios of pulsating heat pipe, this study constructed an experimental platform of pulsating heat pipe with non-uniform heat flux. The platform consists of pulsating heat pipe module, heating module, cooling water circulation module, data measurement and acquisition module, and filling and vacuum working medium module. In order to ensure the reliability of the experimental results, the stability test was carried out. Under the conditions of 50% and 70% liquid filling rate, the performance of heat transfer, evaporation temperature and internal pressure fluctuation characteristics were studied by using ethanol and HFE-7100 as the working mediums and varying the heating power from 40W to 140 W and the dimensionless heat difference from 0 to 0.56. The results show that the HFE-7100 has lower operating thermal resistance at low heating power under uniform heat flux. With the increase of heating power, the thermal resistances of the two kinds of working fluid gradually get close to each other at 50% and 70% filling rate. Alone with the raise of dimensionless heat difference, the operating thermal resistance of the pulsating heat pipe under non-uniform heat flux is lower or close to the uniform heat flux. And the evaporation temperature of the pulsating heat pipe with high liquid filling rate has better stability during start-up and operation. There exists a critical value of dimensionless heat difference (0.33) for pulsating heat pipe under 70% liquid filling rate of non-uniform heat flux. When the value exceeds 0.33, the vapor-liquid working fluid at different heat flux sides can break the equilibrium rapidly, thus improving the circulating flow state and reducing the operating thermal resistance. When the ethanol working medium is heated with a uniform heat flux density, there are a large number of long liquid plugs in the tube under the high liquid filling rate, which is prone to the phenomenon of working medium flow stagnation. When the non-uniform heat flux density is heated, due to the high heat flux density side in the heating section of the device, the moving direction of the working fluid in the pipe of different elbows is consistent, reducing the stagnation and reversal in the internal fluid flow process, so as to improve the heat transfer performance of the pulsating heat pipe device within a certain dimensionless range.

Influence of Vacuum Failure on Heat-Insulating Property of Cryogenic Vessels



CHEN Shuping, SHI Shunbao, ZHU Ming, et al

2022, 50(7):  136-143.  doi:10.12141/j.issn.1000-565X.210668

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Aiming at the vacuum failure of high-vacuum multilayer insulated cryogenic vessel, this paper established a mathematical model for calculating the heat transfer of the annular space with different vacuum failure degrees. A test platform on the vacuum failure insulation performance of cryogenic vessels was built up. The experiment used dry nitrogen as leaking gas to fill the annular space of a 120 L cryogenic vessel with 50% initial filling rate. The boil-off gas, pressure and temperature variations were analyzed when the vacuum degrees of annular space were 10^-3, 1, 10², and 10³ Pa. The results were verified by theoretical calculation. The result shows that the pressure rise rate, boil-off gas and the temperature of ullage in the inner vessels increase with the decrease of vacuum degree of annular space. When the vacuum degree is 10³ Pa, the heat flow density of the cryogenic vessel is 1.32, 12.96, and 122.21 times of that in 10², 1 and 10^-3 Pa, respectively. The maximum boil-off gas is 2.15, 9.69 and 13.77 times of that in 10², 1 and 10^-3 Pa, respectively. With the decrease of the annular space of vacuum degree, the potential safety hazards of cryogenic vessels are gradually aggravated.

Anomaly Detection of Complex Building Energy Consumption System Based on Machine Learning



ZHOU Xuan, WANG Xinyao, YAN Junwei, et al

2022, 50(7):  144-154.  doi:10.12141/j.issn.1000-565X.210422

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The research on the anomaly detection of the operation state of complex energy consumption system is of great significance to the safe, stable, efficient and energy-saving operation of buildings. However, due to the influence of many factors, such as the variety of external environmental factors of buildings, the uncertainty of insider behavior, the complexity of equipment operation data and so on, the detection of abnormal operation state often meets some difficulties in information feature extraction, abnormal operation state definition and so on. Based on the classification of operation parameters and by using the quantitative description of uncertainty by information entropy and the adaptability of unsupervised learning, this paper proposed a secondary clustering anomaly detection method for the operation state of complex energy consumption system based on information entropy and by integrating K-means and self-organizing mapping model. According to the actual monitoring data of the central air-conditioning system of a large office building in the hot summer and warm winter area, the external parameters were clustered for the first time through K-means, and the steps such as dividing the primary working conditions, calculating the information entropy of the operating parameters of the subsystem under each working condition, and determining the abnormal operating state by secondary clustering of self-organizing mapping model were used to realize the abnormal detection of the operating state of the complex energy consumption system of the building. The results show that the average intra class anomaly detection accuracy of the method proposed in this study is 97.45% under the operation condition of single machine and 96.70% under the operation condition of two machines. In addition, this study further discussed and analyzed the relationship between the number of classes and the relevant indicators of in class anomaly rate under different working conditions. It concludes that the in class anomaly detection rate of single and dual hosts increases with the decrease of the total number of operating states in their class. This study provides a new systematic idea and method for the abnormal operation state detection of complex energy consumption system under the background of building energy big data.