The Enlightenment of Updated Development of the USC Coal Fired Units

2017 ◽  
Author(s):  
Ji Wenhao ◽  
Li Daolin ◽  
Hu Xingsheng ◽  
Wan Peng
Keyword(s):  
Flue Gas ◽  
Technical Specification ◽  
Low Grade ◽  
Power Demand ◽  
Production Structure ◽  
Harmful Emission ◽  
The Enlightenment ◽  
Operation Results ◽  
Low Grade Heat ◽  
Further Development

An comparison of technical specification and updated operation results between two USC coal fired boilers namely RDK-8, Germany and WGQ-3, China has been considered under the global scenario related to the variation of industrial production structure, power demand cut down, more stringent carbon dioxide depression and larger quantity of renewable units engaged into the grid, in this respect a discussion and analysis have been carried out subjected to low grade heat recovering and harmful emission prevention from boiler flue gas and introduction carbon harmful emission prevention from boiler flue gas and their multiple benefits on energy saving and environmental protection, moreover the experience and gains in the field of flue gas heat recovering and mitigating pollution, including the proprietary technique (WGGH) by SPERI are briefly stated, thereby a conclusion of enlightenment for further development of these units is mentioned.

scholarly journals Hybrid Membrane Distillation and Wet Scrubber for Simultaneous Recovery of Heat and Water from Flue Gas

Entropy ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 178 ◽  
Author(s):  
Mohd Hizami Mohd Yusoff ◽  
Ein K. Nyunt ◽  
Muhammad Roil Bilad ◽  
Nasrul Arahman ◽  
Sri Mulyati ◽  
...  
Keyword(s):  
Water Vapor ◽  
Flow Rate ◽  
Flue Gas ◽  
Membrane Distillation ◽  
Heat Fluxes ◽  
Low Grade ◽  
Gas Temperature ◽  
Wet Scrubber ◽  
Low Grade Heat ◽  
Water Scrubber

Flue gas contains high amount of low-grade heat and water vapor that are attractive for recovery. This study assesses performance of a hybrid of water scrubber and membrane distillation (MD) to recover both heat and water from a simulated flue gas. The former help to condense the water vapor to form a hot liquid flow which later used as the feed for the MD unit. The system simultaneously recovers water and heat through the MD permeate. Results show that the system performance is dictated by the MD performance since most heat and water can be recovered by the scrubber unit. The scrubber achieved nearly complete water and heat recovery because the flue gas flows were supersaturated with steam condensed in the water scrubber unit. The recovered water and heat in the scrubber contains in the hot liquid used as the feed for the MD unit. The MD performance is affected by both the temperature and the flow rate of the flue gas. The MD fluxes increases at higher flue gas temperatures and higher flow rates because of higher enthalpy of the flue gas inputs. The maximum obtained water and heat fluxes of 12 kg m−2 h−1 and 2505 kJm−2 h−1 respectively, obtained at flue gas temperature of 99 °C and at flow rate of 5.56 L min−1. The MD flux was also found stable over the testing period at this optimum condition. Further study on assessing a more realistic flue gas composition is required to capture complexity of the process, particularly to address the impacts of particulates and acid gases.

scholarly journals Low grade heat recovery system for woodfuel cogeneration plant using water vapour regeneration

2018 ◽  
Vol 22 (6 Part A) ◽  
pp. 2667-2677 ◽  
Author(s):  
Vytautas Dagilis ◽  
Liutauras Vaitkus ◽  
Algimantas Balcius ◽  
Juozas Gudzinskas ◽  
Valdas Lukosevicius
Keyword(s):  
Flue Gas ◽  
Heat Recovery ◽  
Economic Valuation ◽  
Electric Energy ◽  
Low Grade ◽  
Cogeneration Plant ◽  
Recovery System ◽  
Heat Recovery System ◽  
Heat Regeneration ◽  
Low Grade Heat

The paper analyses low grade heat recovery problem for modern woodfuel cogeneration plant. The woodfuel flue gas, behind the condensing economizer, still contains a considerable amount of heat, main part of which is the latent one. To recover this low grade heat, the heat pump technology can be used, which is related with additional consumption of energy (electric, mechanical or heat). Another technique that could be applied is a heat regeneration when flue gas heat, mostly latent, is transmitted to air blown towards burning chamber. Therefore, the analysed heat recovery system operates mainly like mass regenerator which contains only blowers that use some electric energy. The regenerator consists of two cyclically operating columns with packing material. Energetic analysis demonstrates that 13% of additional heat can be produced utilizing this low grade heat. The economic valuation shows that investment in a heat recovery system is quite effective; the payback time is about four years.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

scholarly journals Thermally regenerative electrochemical cycle for low-grade heat harnessing

2021 ◽  
Vol 2 (2) ◽  
pp. 021304
Author(s):  
Hang Zhang ◽  
Qing Wang
Keyword(s):  
Low Grade ◽  
Low Grade Heat

scholarly journals Low‐Grade Heat Harvesting: Efficient Low‐Grade Heat Harvesting Enabled by Tuning the Hydration Entropy in an Electrochemical System (Adv. Mater. 13/2021)

2021 ◽  
Vol 33 (13) ◽  
pp. 2170096
Author(s):  
Caitian Gao ◽  
Yezhou Liu ◽  
Bingbing Chen ◽  
Jeonghun Yun ◽  
Erxi Feng ◽  
...  
Keyword(s):  
Low Grade ◽  
Electrochemical System ◽  
Low Grade Heat

scholarly journals Enhanced Thermoelectric Performance of n-Type Bi2Se3 Nanosheets through Sn Doping

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1827
Author(s):  
Mengyao Li ◽  
Yu Zhang ◽  
Ting Zhang ◽  
Yong Zuo ◽  
Ke Xiao ◽  
...  
Keyword(s):  
Figure Of Merit ◽  
Cost Effective ◽  
Low Grade ◽  
Hot Press ◽  
Processing Technologies ◽  
Sn Doping ◽  
Practical Applications ◽  
Alternative Materials ◽  
The Cost ◽  
Low Grade Heat

The cost-effective conversion of low-grade heat into electricity using thermoelectric devices requires developing alternative materials and material processing technologies able to reduce the currently high device manufacturing costs. In this direction, thermoelectric materials that do not rely on rare or toxic elements such as tellurium or lead need to be produced using high-throughput technologies not involving high temperatures and long processes. Bi2Se3 is an obvious possible Te-free alternative to Bi2Te3 for ambient temperature thermoelectric applications, but its performance is still low for practical applications, and additional efforts toward finding proper dopants are required. Here, we report a scalable method to produce Bi2Se3 nanosheets at low synthesis temperatures. We studied the influence of different dopants on the thermoelectric properties of this material. Among the elements tested, we demonstrated that Sn doping resulted in the best performance. Sn incorporation resulted in a significant improvement to the Bi2Se3 Seebeck coefficient and a reduction in the thermal conductivity in the direction of the hot-press axis, resulting in an overall 60% improvement in the thermoelectric figure of merit of Bi2Se3.

scholarly journals Rolling membrane powered by low-temperature steam as a new approach to generate mechanical energy

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chongshan Yin ◽  
Qicheng Liu ◽  
Qing Liu
Keyword(s):  
Water Vapor ◽  
Low Temperature ◽  
Combustion Engine ◽  
Mechanical Energy ◽  
Heat Energy ◽  
Steam Engine ◽  
Low Grade ◽  
Human Society ◽  
New Approach ◽  
Low Grade Heat

Abstract How to convert heat energy into other forms of usable energy more efficiently is always crucial for our human society. In traditional heat engines, such as the steam engine and the internal combustion engine, high-grade heat energy can be easily converted into mechanical energy, while a large amount of low-grade heat energy is usually wasted owing to its disadvantage in the temperature level. In this work, for the first time, the generation of mechanical energy from both high- and low-temperature steam is implemented by a hydrophilic polymer membrane. When exposed to water vapor with a temperature ranging from 50 to 100 °C, the membrane repeats rolling from one side to another. In nature, this continuously rolling of membrane is powered by the steam, like a miniaturized “steam engine”. The differential concentration of water vapor (steam) on the two sides of the membrane generates the asymmetric swelling, the curve, and the rolling of the membrane. In particular, results suggest that this membrane based “steam engine” can be powered by the steam with a relatively very low temperature of 50 °C, which indicates a new approach to make use of both the high- and low-temperature heat energy.

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