Due to the deterioration of serious energy dilemma,energy-conservation and emission–reduction have been the strategic target in the past decades,thus people have identified the vital importance of higher energy effic...Due to the deterioration of serious energy dilemma,energy-conservation and emission–reduction have been the strategic target in the past decades,thus people have identified the vital importance of higher energy efficiency and the influence of lower carbon development.Since work exchange network is a significant part of energy recovery system,its optima design will have dramatically significant effect on energy consumption reduction in chemical process system.With an extension of the developed transshipment model in isothermal process,a novel step-wise methodology for synthesis of direct work exchange network(WEN)in adiabatic process involving heat integration is first proposed in this paper,where a nonlinear programming(NLP)model is formulated by regarding the minimum utility consumption as objective function and optimizing the initial WEN in accordance with the presented matching rules to get the optimized WEN configuration at first.Furthermore,we focus on the work exchange network synthesis with heat integration to attain the minimal total annual cost(TAC)with the introduction of heat-exchange equipment that is achieved by the following strategies in sequence:introducing heat-exchange equipment directly,adjusting the work quantity of the adjacent utility compressors or expanders,and approximating upper/lower pressure limits consequently to obtain considerable cost savings of expanders or compressors and work utility.Finally,a case taken from the literature is studied to illustrate the feasibility and effectiveness of the proposed method.展开更多
Soils are key natural resources for the Earth's system;however,human impacts,especially,soil erosion are considered serious threats.Therefore,identifying and assessing effective factors to understand erosion hot s...Soils are key natural resources for the Earth's system;however,human impacts,especially,soil erosion are considered serious threats.Therefore,identifying and assessing effective factors to understand erosion hot spots at different scales is critical to developing effective land management plans and ensuring the sustainability of the territory.This study was conducted to determine and prepare an erosion risk map,but to prioritize the survey at different scales,such as sub-basin and watershed ones.To achieve this goal,geographic information system(GIS)and remote sensing data(RS)were used combining the analysis network process method(ANP)and ICONA model(Institute for the Conservation of Nature).As study case,we selected the degraded areas of the Gorganrood watershed located in the north of Iran.The study area was obtained for very low,low,medium,high,and very high-risk classi-fications of 14.0,21.4,17.9,31.3,and 15.4%,respectively.Results from the ICONA model also indicated that 12.8,28.8,22.1,27.9,8.5,and 0.03%belong to very low,low,medium,high,very high,and without risk of erosion,respectively.According to the validation results,it was found that the accuracy of ANP and ICONA models are 0.83 and 0.80,respectively,which indicates the suitability of the models for preparing the erosion map of the region is appropriate and useful for designing land management plans.We conclude that both models can be used to develop the erosion map potential and to prioritize sub-basins if a complete database of geomorphological characteriscs and human activities are accurate previously defined.展开更多
基金Supported by the National Natural Science Foundation of China(21576036,21406026)
文摘Due to the deterioration of serious energy dilemma,energy-conservation and emission–reduction have been the strategic target in the past decades,thus people have identified the vital importance of higher energy efficiency and the influence of lower carbon development.Since work exchange network is a significant part of energy recovery system,its optima design will have dramatically significant effect on energy consumption reduction in chemical process system.With an extension of the developed transshipment model in isothermal process,a novel step-wise methodology for synthesis of direct work exchange network(WEN)in adiabatic process involving heat integration is first proposed in this paper,where a nonlinear programming(NLP)model is formulated by regarding the minimum utility consumption as objective function and optimizing the initial WEN in accordance with the presented matching rules to get the optimized WEN configuration at first.Furthermore,we focus on the work exchange network synthesis with heat integration to attain the minimal total annual cost(TAC)with the introduction of heat-exchange equipment that is achieved by the following strategies in sequence:introducing heat-exchange equipment directly,adjusting the work quantity of the adjacent utility compressors or expanders,and approximating upper/lower pressure limits consequently to obtain considerable cost savings of expanders or compressors and work utility.Finally,a case taken from the literature is studied to illustrate the feasibility and effectiveness of the proposed method.
文摘Soils are key natural resources for the Earth's system;however,human impacts,especially,soil erosion are considered serious threats.Therefore,identifying and assessing effective factors to understand erosion hot spots at different scales is critical to developing effective land management plans and ensuring the sustainability of the territory.This study was conducted to determine and prepare an erosion risk map,but to prioritize the survey at different scales,such as sub-basin and watershed ones.To achieve this goal,geographic information system(GIS)and remote sensing data(RS)were used combining the analysis network process method(ANP)and ICONA model(Institute for the Conservation of Nature).As study case,we selected the degraded areas of the Gorganrood watershed located in the north of Iran.The study area was obtained for very low,low,medium,high,and very high-risk classi-fications of 14.0,21.4,17.9,31.3,and 15.4%,respectively.Results from the ICONA model also indicated that 12.8,28.8,22.1,27.9,8.5,and 0.03%belong to very low,low,medium,high,very high,and without risk of erosion,respectively.According to the validation results,it was found that the accuracy of ANP and ICONA models are 0.83 and 0.80,respectively,which indicates the suitability of the models for preparing the erosion map of the region is appropriate and useful for designing land management plans.We conclude that both models can be used to develop the erosion map potential and to prioritize sub-basins if a complete database of geomorphological characteriscs and human activities are accurate previously defined.
