Over the course of industrial manufacturing,additional heat within the extract systems is usually released into the atmosphere and its intrinsic energy is wasted.This paper investigated a cold abatement smoke extract ...Over the course of industrial manufacturing,additional heat within the extract systems is usually released into the atmosphere and its intrinsic energy is wasted.This paper investigated a cold abatement smoke extract system for a fire testing wall furnace to determine the viability in recovering heat from the hot smoke.Three scenarios were investigated:1)the extract system was closed and only 300°C smoke was present;2)the system took in ambient air around the furnace and heat recovery occurred at 80°C in smoky air;3)the smoke had been removed from the air and the temperature was 60°C.It was found that there was a significant build-up of soot on Scenarios 1&2 with a build-up rate of 0.25𝜇m/s which totalled 2.7 mm of soot after a three-hour test.The soot had a low heat transfer rate and therefore acted as an insulator on the heat exchanger which reduced the efficiency significantly of it over time.Due to this loss in efficiency,it was more viable to recover heat in Scenario 3 at 60°C in clean air than it was to recover heat at 300°C or 80°C in smoky air.The results show that having clean air was more important than a higher temperature when it came from recovering heat from a cold abatement system for a fire testing furnace.This paper contributes to reveal the possibilities of harnessing the“waste heat”for use in other applications in the vicinity of the manufacturing processes,such as heating water within a central heating plant,domestic hot water or electricity generation,or re-cycled within the industrial plant itself.展开更多
SWAT(Soil and Water Assessment Tool)and APEX(Agricultural Policy/Environmental eXtender)are respectively large and small watershed simulation models derived from EPIC(Environmental Policy Integrated Climate),a field-s...SWAT(Soil and Water Assessment Tool)and APEX(Agricultural Policy/Environmental eXtender)are respectively large and small watershed simulation models derived from EPIC(Environmental Policy Integrated Climate),a field-scale agroecology simulation model.All three models are coded in Fortran and have evolved over several decades.They are widely used to analyze anthropogenic influences on soil and water quality and quantity.Much of the original Fortran code has been retained even though Fortran has been through several cycles of development.Fortran now provides functionality originally restricted to languages like C,designed to communicate directly with the operating system and hardware.One can now use an object-oriented style of programming in Fortran,including inheritance,run-time polymorphism and overloading.In order to enhance their utility in research and policy-making,the models are undergoing a major revision to use some of the new Fortran features.With these new programming paradigms the developers of SWAT,APEX,and EPIC are working to make communication between the two models seamless.This paper describes the ongoing revision of these models that will make them easier to use,maintain,modify and document.It is intended that they will converge as they continue to evolution,while maintaining their distinctive features,capabilities and identities.展开更多
Nonpoint source pollution from agriculture is the main source of nitrogen and phosphorus in the stream systems of the Corn Belt region in the Midwestern US.The eastern part of this region is comprised of the Ohio-Tenn...Nonpoint source pollution from agriculture is the main source of nitrogen and phosphorus in the stream systems of the Corn Belt region in the Midwestern US.The eastern part of this region is comprised of the Ohio-Tennessee River Basin(OTRB),which is considered a key contributing area for water pollution and the Northern Gulf of Mexico hypoxic zone.A point of crucial importance in this basin is therefore how intensive corn-based cropping systems for food and fuel production can be sustainable and coexist with a healthy water environment,not only under existing climate but also under climate change conditions in the future.To address this issue,a OTRB integrated modeling system has been built with a greatly refined 12-digit subbasin structure based on the Soil and Water Assessment Tool(SWAT)water quality model,which is capable of estimating landscape and in-stream water and pollutant yields in response to a wide array of alternative cropping and/or management strategies and climatic conditions.The effects of three agricultural management scenarios on crop production and pollutant loads exported from the crop land of the OTRB to streams and rivers were evaluated:(1)expansion of continuous corn across the entire basin,(2)adoption of no-till on all corn and soybean fields in the region,(3)implementation of a winter cover crop within the baseline rotations.The effects of each management scenario were evaluated both for current climate and projected mid-century(2046-2065)climates from seven global circulation models(GCMs).In both present and future climates each management scenario resulted in reduced erosion and nutrient loadings to surface water bodies compared to the baseline agricultural management,with cover crops causing the highest water pollution reduction.Corn and soybean yields in the region were negligibly influenced from the agricultural management scenarios.On the other hand,both water quality and crop yield numbers under climate change deviated considerably for all seven GCMs compared to the baseline climate.Future climates from all GCMs led to decreased corn and soybean yields by up to 20%on a mean annual basis,while water quality alterations were either positive or negative depending on the GCM.The study highlights the loss of productivity in the eastern Corn Belt under climate change,the need to consider a range of GCMs when assessing impacts of climate change,and the value of SWAT as a tool to analyze the effects of climate change on parameters of interest at the basin scale.展开更多
文摘Over the course of industrial manufacturing,additional heat within the extract systems is usually released into the atmosphere and its intrinsic energy is wasted.This paper investigated a cold abatement smoke extract system for a fire testing wall furnace to determine the viability in recovering heat from the hot smoke.Three scenarios were investigated:1)the extract system was closed and only 300°C smoke was present;2)the system took in ambient air around the furnace and heat recovery occurred at 80°C in smoky air;3)the smoke had been removed from the air and the temperature was 60°C.It was found that there was a significant build-up of soot on Scenarios 1&2 with a build-up rate of 0.25𝜇m/s which totalled 2.7 mm of soot after a three-hour test.The soot had a low heat transfer rate and therefore acted as an insulator on the heat exchanger which reduced the efficiency significantly of it over time.Due to this loss in efficiency,it was more viable to recover heat in Scenario 3 at 60°C in clean air than it was to recover heat at 300°C or 80°C in smoky air.The results show that having clean air was more important than a higher temperature when it came from recovering heat from a cold abatement system for a fire testing furnace.This paper contributes to reveal the possibilities of harnessing the“waste heat”for use in other applications in the vicinity of the manufacturing processes,such as heating water within a central heating plant,domestic hot water or electricity generation,or re-cycled within the industrial plant itself.
文摘SWAT(Soil and Water Assessment Tool)and APEX(Agricultural Policy/Environmental eXtender)are respectively large and small watershed simulation models derived from EPIC(Environmental Policy Integrated Climate),a field-scale agroecology simulation model.All three models are coded in Fortran and have evolved over several decades.They are widely used to analyze anthropogenic influences on soil and water quality and quantity.Much of the original Fortran code has been retained even though Fortran has been through several cycles of development.Fortran now provides functionality originally restricted to languages like C,designed to communicate directly with the operating system and hardware.One can now use an object-oriented style of programming in Fortran,including inheritance,run-time polymorphism and overloading.In order to enhance their utility in research and policy-making,the models are undergoing a major revision to use some of the new Fortran features.With these new programming paradigms the developers of SWAT,APEX,and EPIC are working to make communication between the two models seamless.This paper describes the ongoing revision of these models that will make them easier to use,maintain,modify and document.It is intended that they will converge as they continue to evolution,while maintaining their distinctive features,capabilities and identities.
基金This research was partially funded by the National Science Foundation,Award No.DEB1010259,Understanding Land Use Decisions&Watershed Scale Interactions:Water Quality in the Mississippi River Basin&Hypoxic Conditions in the Gulf of Mexicoby the U.S.Department of Agriculture,National Institute of Food and Agriculture,Award No.20116800230190,Climate Change,Mitigation,and Adaptation In Corn-Based Cropping Systems.
文摘Nonpoint source pollution from agriculture is the main source of nitrogen and phosphorus in the stream systems of the Corn Belt region in the Midwestern US.The eastern part of this region is comprised of the Ohio-Tennessee River Basin(OTRB),which is considered a key contributing area for water pollution and the Northern Gulf of Mexico hypoxic zone.A point of crucial importance in this basin is therefore how intensive corn-based cropping systems for food and fuel production can be sustainable and coexist with a healthy water environment,not only under existing climate but also under climate change conditions in the future.To address this issue,a OTRB integrated modeling system has been built with a greatly refined 12-digit subbasin structure based on the Soil and Water Assessment Tool(SWAT)water quality model,which is capable of estimating landscape and in-stream water and pollutant yields in response to a wide array of alternative cropping and/or management strategies and climatic conditions.The effects of three agricultural management scenarios on crop production and pollutant loads exported from the crop land of the OTRB to streams and rivers were evaluated:(1)expansion of continuous corn across the entire basin,(2)adoption of no-till on all corn and soybean fields in the region,(3)implementation of a winter cover crop within the baseline rotations.The effects of each management scenario were evaluated both for current climate and projected mid-century(2046-2065)climates from seven global circulation models(GCMs).In both present and future climates each management scenario resulted in reduced erosion and nutrient loadings to surface water bodies compared to the baseline agricultural management,with cover crops causing the highest water pollution reduction.Corn and soybean yields in the region were negligibly influenced from the agricultural management scenarios.On the other hand,both water quality and crop yield numbers under climate change deviated considerably for all seven GCMs compared to the baseline climate.Future climates from all GCMs led to decreased corn and soybean yields by up to 20%on a mean annual basis,while water quality alterations were either positive or negative depending on the GCM.The study highlights the loss of productivity in the eastern Corn Belt under climate change,the need to consider a range of GCMs when assessing impacts of climate change,and the value of SWAT as a tool to analyze the effects of climate change on parameters of interest at the basin scale.