• Energy Research
• Restricted close
• other engineering and technologies close
• PL close
• AT close

The Municipal Solid Waste Management (MSWM) sector has developed considerably during the past century, paving the way for maximum resource (materials and energy) recovery and minimising environmental impacts such as global warming associated with it. The current study is assessing the historical development of MSWM in the municipality of Aalborg, Denmark throughout the period of 1970 to 2010, and its implications regarding Global Warming Potential (GWP(100)), using the Life Cycle Assessment (LCA) approach. Historical data regarding MSW composition, and different treatment technologies such as incineration, recycling and composting has been used in order to perform the analysis. The LCA results show a continuous improvement in environmental performance of MSWM from 1970 to 2010 mainly due to the changes in treatment options, improved efficiency of various treatment technologies and increasing focus on recycling, resulting in a shift from net emission of 618 kg CO(2)-eq.tonne(-1) to net saving of 670 kg CO(2)-eq.tonne(-1) of MSWM.

The Municipal Solid Waste Management (MSWM) sector has developed considerably during the past century, paving the way for maximum resource (materials and energy) recovery and minimising environmental impacts such as global warming associated with it. The current study is assessing the historical development of MSWM in the municipality of Aalborg, Denmark throughout the period of 1970 to 2010, and its implications regarding Global Warming Potential (GWP(100)), using the Life Cycle Assessment (LCA) approach. Historical data regarding MSW composition, and different treatment technologies such as incineration, recycling and composting has been used in order to perform the analysis. The LCA results show a continuous improvement in environmental performance of MSWM from 1970 to 2010 mainly due to the changes in treatment options, improved efficiency of various treatment technologies and increasing focus on recycling, resulting in a shift from net emission of 618 kg CO(2)-eq.tonne(-1) to net saving of 670 kg CO(2)-eq.tonne(-1) of MSWM.

Localization of hotspots and critical aging segments of transmission lines is important for operation and asset management of power transmission systems. Conductors can lose their tensile strength due to the adverse effects of conductor aging caused by annealing. Although the loss of conductor strength is gradual, it accumulates over time and increases the probability of outages and blackouts. Therefore, it is important to keep track of conductor temperatures over time and in space, in order to identify segments of power transmission network that may require more close attention, repairs, or reinforcements. This paper describes and illustrates a new methodology for localization of hotspots and identification of critical aging segments of power transmission lines. The methodology uses load information and weather conditions derived from historical weather reanalysis to derive a time series of spatially resolved map of conductor temperatures. The temperature map is then used to estimate loss of conductor tensile strength for each span of the transmission line. The process is illustrated for a sample transmission line, using assumed load current and historical weather information spanning a period of five years. The simulation results show that the proposed approach provides information vital for transmission network operating procedures and transmission asset management.

Localization of hotspots and critical aging segments of transmission lines is important for operation and asset management of power transmission systems. Conductors can lose their tensile strength due to the adverse effects of conductor aging caused by annealing. Although the loss of conductor strength is gradual, it accumulates over time and increases the probability of outages and blackouts. Therefore, it is important to keep track of conductor temperatures over time and in space, in order to identify segments of power transmission network that may require more close attention, repairs, or reinforcements. This paper describes and illustrates a new methodology for localization of hotspots and identification of critical aging segments of power transmission lines. The methodology uses load information and weather conditions derived from historical weather reanalysis to derive a time series of spatially resolved map of conductor temperatures. The temperature map is then used to estimate loss of conductor tensile strength for each span of the transmission line. The process is illustrated for a sample transmission line, using assumed load current and historical weather information spanning a period of five years. The simulation results show that the proposed approach provides information vital for transmission network operating procedures and transmission asset management.

In terms of energy efficiency and the quality of the indoor and outdoor environment, heritage buildings are facing sustainability challenges. This study assessed the feasibility of using renewable energy sources based on air-to-water heat pumps with regard to preserving the historic values of the buildings and their ability to coexist with current energy efficiency and decarbonization requirements, and to prevent their neglect and degradation. A new approach is the use of Building Information Modelling to accurately determine energy demand and select a heating system based on renewable energy sources in such an unusual case as a heritage building. The analysis covers a selection of feasible scenario of the modernization of the over 300 years old building. A particular focus of the study is to compare the use different heat pumps systems. One is a reversible gas absorption air-to-water heat pump and the other is an electricity-powered compressor air-to-water heat pump. The building is currently supplied with a fixed-temperature boiler up to 550 kW with an open combustion chamber fed with coal. It was proven that the proposed retrofit scenario reduces final energy demand by 72.9%, while improving thermal comfort, cutting annual emissions by 121.1 Mg CO2 and 1.0 Mg PM10.

In terms of energy efficiency and the quality of the indoor and outdoor environment, heritage buildings are facing sustainability challenges. This study assessed the feasibility of using renewable energy sources based on air-to-water heat pumps with regard to preserving the historic values of the buildings and their ability to coexist with current energy efficiency and decarbonization requirements, and to prevent their neglect and degradation. A new approach is the use of Building Information Modelling to accurately determine energy demand and select a heating system based on renewable energy sources in such an unusual case as a heritage building. The analysis covers a selection of feasible scenario of the modernization of the over 300 years old building. A particular focus of the study is to compare the use different heat pumps systems. One is a reversible gas absorption air-to-water heat pump and the other is an electricity-powered compressor air-to-water heat pump. The building is currently supplied with a fixed-temperature boiler up to 550 kW with an open combustion chamber fed with coal. It was proven that the proposed retrofit scenario reduces final energy demand by 72.9%, while improving thermal comfort, cutting annual emissions by 121.1 Mg CO2 and 1.0 Mg PM10.

In this work, the effect of initial temperature on the explosion pressure, Pex, of various liquid fuels (isooctane, toluene and methanol) and their blends (isooctane-toluene and methanol-toluene, with three different fuel-fuel ratios) was investigated by performing experiments in a 20-l sphere at different concentrations of vaporized fuel in air. The initial temperature was varied from 333 K to 413 K. Results show that, as the fuel-air equivalence ratio, Φ, is increased, a transition occurs from a “thermodynamics-driven” explosion regime to a “radiant heat losses-driven” explosion regime. The maximum pressure, Pmax, is found in the former regime (Φ 3), Pex increases with increasing initial temperature. This trend has been addressed to the decrease in emissivity (and, thus, radiant heat losses) with the increase in temperature brak

In this work, the effect of initial temperature on the explosion pressure, Pex, of various liquid fuels (isooctane, toluene and methanol) and their blends (isooctane-toluene and methanol-toluene, with three different fuel-fuel ratios) was investigated by performing experiments in a 20-l sphere at different concentrations of vaporized fuel in air. The initial temperature was varied from 333 K to 413 K. Results show that, as the fuel-air equivalence ratio, Φ, is increased, a transition occurs from a “thermodynamics-driven” explosion regime to a “radiant heat losses-driven” explosion regime. The maximum pressure, Pmax, is found in the former regime (Φ 3), Pex increases with increasing initial temperature. This trend has been addressed to the decrease in emissivity (and, thus, radiant heat losses) with the increase in temperature brak