Interpretative structural model(ISM) can transform a multivariate problem into several sub-variable problems to analyze a complex industrial structure in a more efficient way by building a multi-level hierarchical str...Interpretative structural model(ISM) can transform a multivariate problem into several sub-variable problems to analyze a complex industrial structure in a more efficient way by building a multi-level hierarchical structure model. To build an ISM of a production system, the partial correlation coefficient method is proposed to obtain the adjacency matrix, which can be transformed to ISM. According to estimation of correlation coefficient, the result can give actual variable correlations and eliminate effects of intermediate variables. Furthermore, this paper proposes an effective approach using ISM to analyze the main factors and basic mechanisms that affect the energy consumption in an ethylene production system. The case study shows that the proposed energy consumption analysis method is valid and efficient in improvement of energy efficiency in ethylene production.展开更多
The electric energy consumed in every ton of acceptable product, namely energy consumption per ton (ECT), is an important overall index for the production process of a fused magnesium furnace. The furnace is the equip...The electric energy consumed in every ton of acceptable product, namely energy consumption per ton (ECT), is an important overall index for the production process of a fused magnesium furnace. The furnace is the equipment for producing the fused magnesia. The ECT value depends on the current in the smelting process. The optimal operation for a fused magnesium furnace is supposed to have the ECT as low as possible, where the key is to predict ECT accurately. By introducing an unknown high-order non linear term, this paper builds a dynamic ECT model for differe nt production batches based on the static ECT model for one batch. The average current is taken as the input of the dynamic ECT model, which is composed of the unknown high-order nonlinear term and a nonlinear model with unknown parameters. The order of the nonlinear term is determined by the distance correlatio n and the nonlinear term is estimated by the stochastic con figuration n etwork, while the parameters of the non linear model is ide ntified by the least square method. The estimation of the nonli near term alter nates with the parameter identification. This paper proposes a prediction method for ECT, which is composed of the order identification of the non linear term, the alternating identification of the model and the ECT prediction model. The simulation experiments are conducted by the on-site data, and the results verify the effectiveness of the proposed prediction method.展开更多
Switchable multi-layer ethylene tetra-fluoro-ethylene(ETFE)cushion controls the natural light and heat flux passing through the cushion with varying outdoor conditions by dynamically modifying its properties.In this p...Switchable multi-layer ethylene tetra-fluoro-ethylene(ETFE)cushion controls the natural light and heat flux passing through the cushion with varying outdoor conditions by dynamically modifying its properties.In this paper,the switchable ETFE cushions with ink printing of different optical and thermal properties were adopted as the window in a typical office model,and the indoor daylight and energy consumption were simulated by using Grasshopper software.Experimental model was built to validate the numerical model.Five locations representing five climate zones in China were selected to analyze the feasibility of the switchable ETFE cushion in different climates.The hourly indoor daylight and heat gain in a single day revealed the effects of the dynamic mechanism of ETFE cushion in improving indoor natural light and thermal environment.In addition,the annual daylight performance at the working area(1.5 m from the window)was simulated.ETFE cushion with printing of the lowest transmittance(ETFE1)was the optimal option for most cities and window-to-wall ratios,with the percentage of annual useful daylight hours up to 78.6%,except for the cases where the window-to-wall ratio(WWR)was 0.35 in Harbin,Beijing,and Hefei.The distribution of useful daylight hours revealed that ETFE cushions with low,medium,and high printing transmittance were suitable for offices where people work in the front,medium,and back region of the room,respectively.Energy consumption calculation revealed that ETFE1 showed advantages over other windows in most cities except for cities highly dominated by heating.ETFE1 delivered up to 33%of energy saving over a year in Kunming compared with the conventional double glazing but was not superior in cities with high heating and low cooling demands,such as Harbin.展开更多
基金Supported by the National Natural Science Foundation of China(61374166,6153303)the Doctoral Fund of Ministry of Education of China(20120010110010)the Fundamental Research Funds for the Central Universities(YS1404,JD1413,ZY1502)
文摘Interpretative structural model(ISM) can transform a multivariate problem into several sub-variable problems to analyze a complex industrial structure in a more efficient way by building a multi-level hierarchical structure model. To build an ISM of a production system, the partial correlation coefficient method is proposed to obtain the adjacency matrix, which can be transformed to ISM. According to estimation of correlation coefficient, the result can give actual variable correlations and eliminate effects of intermediate variables. Furthermore, this paper proposes an effective approach using ISM to analyze the main factors and basic mechanisms that affect the energy consumption in an ethylene production system. The case study shows that the proposed energy consumption analysis method is valid and efficient in improvement of energy efficiency in ethylene production.
基金National Natural Science Foundation of China (Nos. 61525302, 61590922, 61503066, 61533007)in part by the Project of Industry and Information Technology Ministry (No. 20171122-6)in part by the Projects of Shenyang (No. Y17-0-004).
文摘The electric energy consumed in every ton of acceptable product, namely energy consumption per ton (ECT), is an important overall index for the production process of a fused magnesium furnace. The furnace is the equipment for producing the fused magnesia. The ECT value depends on the current in the smelting process. The optimal operation for a fused magnesium furnace is supposed to have the ECT as low as possible, where the key is to predict ECT accurately. By introducing an unknown high-order non linear term, this paper builds a dynamic ECT model for differe nt production batches based on the static ECT model for one batch. The average current is taken as the input of the dynamic ECT model, which is composed of the unknown high-order nonlinear term and a nonlinear model with unknown parameters. The order of the nonlinear term is determined by the distance correlatio n and the nonlinear term is estimated by the stochastic con figuration n etwork, while the parameters of the non linear model is ide ntified by the least square method. The estimation of the nonli near term alter nates with the parameter identification. This paper proposes a prediction method for ECT, which is composed of the order identification of the non linear term, the alternating identification of the model and the ECT prediction model. The simulation experiments are conducted by the on-site data, and the results verify the effectiveness of the proposed prediction method.
基金supported by grants from the Key Research and Development Program of Anhui Province(No.S202004a07020029)National Natural Science Foundation of China(No.51908174)Anhui Provincial Natural Science Foundation(No.1908085QE206).
文摘Switchable multi-layer ethylene tetra-fluoro-ethylene(ETFE)cushion controls the natural light and heat flux passing through the cushion with varying outdoor conditions by dynamically modifying its properties.In this paper,the switchable ETFE cushions with ink printing of different optical and thermal properties were adopted as the window in a typical office model,and the indoor daylight and energy consumption were simulated by using Grasshopper software.Experimental model was built to validate the numerical model.Five locations representing five climate zones in China were selected to analyze the feasibility of the switchable ETFE cushion in different climates.The hourly indoor daylight and heat gain in a single day revealed the effects of the dynamic mechanism of ETFE cushion in improving indoor natural light and thermal environment.In addition,the annual daylight performance at the working area(1.5 m from the window)was simulated.ETFE cushion with printing of the lowest transmittance(ETFE1)was the optimal option for most cities and window-to-wall ratios,with the percentage of annual useful daylight hours up to 78.6%,except for the cases where the window-to-wall ratio(WWR)was 0.35 in Harbin,Beijing,and Hefei.The distribution of useful daylight hours revealed that ETFE cushions with low,medium,and high printing transmittance were suitable for offices where people work in the front,medium,and back region of the room,respectively.Energy consumption calculation revealed that ETFE1 showed advantages over other windows in most cities except for cities highly dominated by heating.ETFE1 delivered up to 33%of energy saving over a year in Kunming compared with the conventional double glazing but was not superior in cities with high heating and low cooling demands,such as Harbin.
