Wireless sensor networks are widely used for monitoring in remote areas. They mainly consist of wireless sensor nodes, which are usually powered by batteries with limited capacity, but are expected to last for long pe...Wireless sensor networks are widely used for monitoring in remote areas. They mainly consist of wireless sensor nodes, which are usually powered by batteries with limited capacity, but are expected to last for long periods of time. To overcome these limitations and achieve perpetual autonomy, an energy harvesting technique using a thermoelectric generator (TEG) coupled with storage on supercapacitors is proposed. The originality of the work lies in the presentation of a maintenance-free, robust, and tested solution, well adapted to a harsh industrial context with a permanent temperature gradient. The harvesting part, which is attached to the hot spot in a few seconds using magnets, can withstand temperatures of 200°C. The storage unit, which contains the electronics and supercapacitors, operates at temperatures of up to 80°C. More specifically, this article describes the final design of a 3.3 V 60 mA battery-free power supply. An analysis of the thermal potential and the electrical power that can be recovered is presented, followed by the design of the main electronic stages: energy recovery using a BQ25504, storage on supercapacitors and finally shaping the output voltage with a boost (TPS610995) followed by an LDO (TPS71533).展开更多
Three generation systems, namely, steam Rankine cycle （SRC）, organic Rankine cycle （ORC）, and steam-organic combined Rankine cycle （S-ORC）, were simulated using the Engineering Equation Solver fEES） to efficien...Three generation systems, namely, steam Rankine cycle （SRC）, organic Rankine cycle （ORC）, and steam-organic combined Rankine cycle （S-ORC）, were simulated using the Engineering Equation Solver fEES） to efficiently utilize flue gas emissions from 200 to 450 ℃ in iron and steel plants. Based on the simulation results for thermal efficiency, exergy efficiency, and power generation, the performances of the three power generation systems were compared and analyzed. To further utilize waste heat from the turbine exhaust steam of the ORC system, cas- cade （）RC （CORC） was designed for heat sources above 300 ℃. Based on a comprehensive performance comparison, the application of the ORC using R141b is preferable for 200 to 300 ℃ flue gas. For 300 to 450 ℃ flue gas, CORC is an alternative technology to improve the efficiency and quality of waste heat utilization. For flue gas above 450 ℃, S-ORC can achieve higher efficiency and power generation than conventional SRC, with a relatively small negative pressure and high dryness of the turbine outlet steam. Hence, S-ORC can be considered as a substitute for SRC.展开更多
When it comes to water and energy, it is hard to obtain one without the other. Water is required to produce energy and energy is necessary in water production and management. As demands for water are escalating due to...When it comes to water and energy, it is hard to obtain one without the other. Water is required to produce energy and energy is necessary in water production and management. As demands for water are escalating due to rapid population growth and urbanization, understanding and quantification of the interdependency between water and energy, along with analyzing nexus interactions, trade-offs and risks are a pre-requisite for effective and integrated planning and management of these two key sectors. This paper performs an assessment of the water-energy nexus in the municipal sector of the Eastern Province of Saudi Arabia, where the electric energy footprint in the water value chain (groundwater, desalination and wastewater treatment) and the water footprint in electric energy generation (thermal power plants) are quantified using data for the year 2013. The results confirmed the high and strong dependency on energy for the municipal water cycle in the Eastern Province and revealed that energy generation dependency on freshwater resources is also major and evident, especially at farther distances from the coastal areas. Thermal desalination is by far the most energy intensive stage among the entire Eastern Province water cycle. In 2013, it was estimated 13% of the Eastern Province energy generation capacity goes for desalination, that’s a 5% of the Kingdom capacity. Substantial energy input for desalination in the Eastern Province is attributed to the production and conveyance of water to the Capital Riyadh (48.9 kWh/m3 and 4.2 kWh/m3 respectively). As for groundwater pumping, it was estimated that 206.2 GWH was used for pumping 268 MCM in 2013 (0.764 kWh/m3). Energy requirement for primary, secondary and tertiary wastewater treatment was found to be the least (2 - 108 GWH) and was equivalent to an average of 0.4 kWh/m3. The water footprint in electricity generation was estimated to be about 739,308 m3 in 2013 (0.125 m3/kWh), a relatively higher value compared to the norm of gas combustion turbine cooling water re展开更多
文摘Wireless sensor networks are widely used for monitoring in remote areas. They mainly consist of wireless sensor nodes, which are usually powered by batteries with limited capacity, but are expected to last for long periods of time. To overcome these limitations and achieve perpetual autonomy, an energy harvesting technique using a thermoelectric generator (TEG) coupled with storage on supercapacitors is proposed. The originality of the work lies in the presentation of a maintenance-free, robust, and tested solution, well adapted to a harsh industrial context with a permanent temperature gradient. The harvesting part, which is attached to the hot spot in a few seconds using magnets, can withstand temperatures of 200°C. The storage unit, which contains the electronics and supercapacitors, operates at temperatures of up to 80°C. More specifically, this article describes the final design of a 3.3 V 60 mA battery-free power supply. An analysis of the thermal potential and the electrical power that can be recovered is presented, followed by the design of the main electronic stages: energy recovery using a BQ25504, storage on supercapacitors and finally shaping the output voltage with a boost (TPS610995) followed by an LDO (TPS71533).
基金Sponsored by Science and Technology Commission Foundation of Jiangsu Province of China(BA2010035)
文摘Three generation systems, namely, steam Rankine cycle （SRC）, organic Rankine cycle （ORC）, and steam-organic combined Rankine cycle （S-ORC）, were simulated using the Engineering Equation Solver fEES） to efficiently utilize flue gas emissions from 200 to 450 ℃ in iron and steel plants. Based on the simulation results for thermal efficiency, exergy efficiency, and power generation, the performances of the three power generation systems were compared and analyzed. To further utilize waste heat from the turbine exhaust steam of the ORC system, cas- cade （）RC （CORC） was designed for heat sources above 300 ℃. Based on a comprehensive performance comparison, the application of the ORC using R141b is preferable for 200 to 300 ℃ flue gas. For 300 to 450 ℃ flue gas, CORC is an alternative technology to improve the efficiency and quality of waste heat utilization. For flue gas above 450 ℃, S-ORC can achieve higher efficiency and power generation than conventional SRC, with a relatively small negative pressure and high dryness of the turbine outlet steam. Hence, S-ORC can be considered as a substitute for SRC.
文摘When it comes to water and energy, it is hard to obtain one without the other. Water is required to produce energy and energy is necessary in water production and management. As demands for water are escalating due to rapid population growth and urbanization, understanding and quantification of the interdependency between water and energy, along with analyzing nexus interactions, trade-offs and risks are a pre-requisite for effective and integrated planning and management of these two key sectors. This paper performs an assessment of the water-energy nexus in the municipal sector of the Eastern Province of Saudi Arabia, where the electric energy footprint in the water value chain (groundwater, desalination and wastewater treatment) and the water footprint in electric energy generation (thermal power plants) are quantified using data for the year 2013. The results confirmed the high and strong dependency on energy for the municipal water cycle in the Eastern Province and revealed that energy generation dependency on freshwater resources is also major and evident, especially at farther distances from the coastal areas. Thermal desalination is by far the most energy intensive stage among the entire Eastern Province water cycle. In 2013, it was estimated 13% of the Eastern Province energy generation capacity goes for desalination, that’s a 5% of the Kingdom capacity. Substantial energy input for desalination in the Eastern Province is attributed to the production and conveyance of water to the Capital Riyadh (48.9 kWh/m3 and 4.2 kWh/m3 respectively). As for groundwater pumping, it was estimated that 206.2 GWH was used for pumping 268 MCM in 2013 (0.764 kWh/m3). Energy requirement for primary, secondary and tertiary wastewater treatment was found to be the least (2 - 108 GWH) and was equivalent to an average of 0.4 kWh/m3. The water footprint in electricity generation was estimated to be about 739,308 m3 in 2013 (0.125 m3/kWh), a relatively higher value compared to the norm of gas combustion turbine cooling water re
