scholarly journals Energy and CO2 Reduction of Aluminum Powder Molds for Producing Free-Form Concrete Panels

2020 ◽  
Vol 12 (22) ◽  
pp. 9613
Author(s):  
Donghoon Lee ◽  
Sunkuk Kim
Keyword(s):  
Co2 Emissions ◽  
Aluminum Powder ◽  
Energy Use ◽  
Phase Change Materials ◽  
Co2 Reduction ◽  
Free Form ◽  
Cnc Machine ◽  
Repeated Heating ◽  
Concrete Panels ◽  
Reduction Effect

Free-form design may enhance the architectural value of buildings in terms of aesthetic and symbolic effects. However, it is difficult to reuse the mold of free-form concrete segments, so they are manufactured for single use. Manufacturing these molds is a time-consuming process that requires a lot of manpower. To solve these problems, there have been numerous studies on the use of phase change materials (PCMs) to make the molds. PCM molds represent a new technique of producing free-form panels using a computerized numeric control (CNC) machine that employs low-cost material to produce free-form concrete panels. However, PCM molds require a substantial amount of time and energy during fabrication because repeated heating and cooling cycles are required during panel production, and this process increases the CO2 emissions. Thus, the purposes of this study were to develop composite molds using aluminum powder to improve PCM mold performance and to conduct experiments to quantify the reduction of energy use and CO2 emissions. As a result of cooling experiments, it was found that the aluminum powder mold had an energy reduction effect of 14.3% against the PCM mold that had been produced only with paraffin wax, and CO2 reduction effect of more than 50% against the conventional mold.

scholarly journals Development of Sustainable Production Technology of Free-Form Concrete Panels Using a Multi-Point Press CNC Machine

2021 ◽  
Vol 13 (4) ◽  
pp. 1990
Author(s):  
Sunkuk Kim ◽  
Seunghyun Son ◽  
Donghoon Lee
Keyword(s):  
Production Technology ◽  
Technological Development ◽  
Free Form ◽  
Cnc Machine ◽  
Silicon Plate ◽  
Shape Accuracy ◽  
Concrete Panels ◽  
Short Period ◽  
The Mean ◽  
Concrete Materials

Maintaining shape accuracy in the production of concrete panels of free-form buildings is time-consuming and costly. In addition, disposable molds used for free-form panels are not sustainable. Such problems can be solved by developing a suitable computerized numeric control (CNC) machine that can produce an accurately shaped reusable form for free-form concrete materials in a short period of time. This project develops a production technology of quality free-form concrete panels using a CNC machine and verifies the shape quality through an experiment. We designed a multi-point press CNC machine and verified its quality. The CNC machine implements a smooth free-form shape by changing the shape of the silicon plate by movement of the rods. The silicone plate for the CNC machine generates a slight error due to the elastic cover and mechanical clearance. The mean error rate was within 3%, based on the thickness of the panels, at the 95% confidence level. Verification of these errors will provide meaningful information to a similar type of machine development. In addition, the project results will be helpful in technological development for the production of free-form concrete panels of uniform quality, whose shape accuracy is not influenced by the skills and competence of the workers producing the panels.

scholarly journals AN EXPERIMENTAL STUDY FOR QUALITY ASSURANCE OF FREE-FORM CONCRETE PANELS PRODUCED BY CNC MACHINE

2018 ◽  
Vol 24 (2) ◽  
pp. 145-154 ◽  
Author(s):  
Jeeyoung LIM ◽  
Do Yeong KIM ◽  
Sunkuk KIM
Keyword(s):  
Experimental Study ◽  
Quality Assurance ◽  
Labor Cost ◽  
Free Form ◽  
Shape Error ◽  
Cnc Machine ◽  
Concrete Panels ◽  
Short Time ◽  
Change Material

Various studies have been conducted to construct free-form buildings, but it still takes a lot of labor, cost, and time to assure the accuracy of designed shapes. In particular, molds for the production of free-form concrete panels (FCPs) are putting enormous burdens on productivity and cost. To produce FCPs economically, a computerized numeric control (CNC) machine that produces phase change material (PCM) molds for persistent use was developed in this study. The technology using CNC machine can produce precisely free-form molds and panels in a short time compared to the manual method. However, in order to commercialize this technology, it is necessary to verify the shape error of the FCPs. Therefore, the purpose of this paper is an experimental study for securing FCP quality produced by a CNC machine. The results of this study will be used to mass-produce uniform quality of FCPs without depending on the skill and workmanship of the labo.

scholarly journals Greenhouse Gas Reduction Effect of Solar Energy Systems Applicable to High-rise Apartment Housing Structures in South Korea

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2568 ◽  
Author(s):  
Chang-Hyun Park ◽  
Yu-Jin Ko ◽  
Jong-Hyun Kim ◽  
Hiki Hong
Keyword(s):  
South Korea ◽  
Greenhouse Gas ◽  
Energy Use ◽  
Azimuthal Angle ◽  
Vertical Wall ◽  
Co2 Reduction ◽  
High Rise ◽  
Greenhouse Gas Reduction ◽  
Net Zero ◽  
Reduction Effect

In South Korea, we are aiming for net zero energy use apartment home structures. Since the apartment structure in South Korea is generally a high-rise of 10 or more floors, the types of renewable energy applicable are limited to photovoltaic (PV) panels, solar collectors installed on the wall, or a photovoltaic thermal (PVT) hybrid panel combining both. In this study, the effect of PV, ST (Solar Thermal), and PVT systems on greenhouse gas reduction was analyzed using TRNSYS18. All three systems showed maximum CO2 reductions at 35° facing south. PV, ST, and PVT showed CO2 reductions of 67.4, 114.6, and 144.7 kg_CO2/m2·year, respectively. Compared to those values, when installed on a wall (slope of 90°), CO2 reduction is about 35–40% less and about 20% less at a slope of 75°. ST and PVT installed on the vertical wall have a greater greenhouse gas reduction effect than the PV installed at the optimal slope of 35°. Since the CO2 reduction difference among SW, SE, and azimuthal S is within 10%, ST and PVT are recommended for installation on high-rise apartment structure walls or balconies with the azimuthal angle of ± 45° with respect to south.

scholarly journals CO2 Intensities and Primary Energy Factors in the Future European Electricity System

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2165
Author(s):  
Sam Hamels
Keyword(s):  
Co2 Emissions ◽  
Energy Use ◽  
Conversion Factor ◽  
Unit Commitment ◽  
Primary Energy ◽  
High Temporal Resolution ◽  
The European Union ◽  
Electricity System ◽  
Energy Factors ◽  
Electrical Loads

The European Union strives for sharp reductions in both CO2 emissions as well as primary energy use. Electricity consuming technologies are becoming increasingly important in this context, due to the ongoing electrification of transport and heating services. To correctly evaluate these technologies, conversion factors are needed—namely CO2 intensities and primary energy factors (PEFs). However, this evaluation is hindered by the unavailability of a high-quality database of conversion factor values. Ideally, such a database has a broad geographical scope, a high temporal resolution and considers cross-country exchanges of electricity as well as future evolutions in the electricity mix. In this paper, a state-of-the-art unit commitment economic dispatch model of the European electricity system is developed and a flow-tracing technique is innovatively applied to future scenarios (2025–2040)—to generate such a database and make it publicly available. Important dynamics are revealed, including an overall decrease in conversion factor values as well as considerable temporal variability at both the seasonal and hourly level. Furthermore, the importance of taking into account imports and carefully considering the calculation methodology for PEFs are both confirmed. Future estimates of the CO2 emissions and primary energy use associated with individual electrical loads can be meaningfully improved by taking into account these dynamics.

scholarly journals Future Power Train Solutions for Long-Haul Trucks

2021 ◽  
Vol 13 (4) ◽  
pp. 2225
Author(s):  
Ralf Peters ◽  
Janos Lucian Breuer ◽  
Maximilian Decker ◽  
Thomas Grube ◽  
Martin Robinius ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Co2 Emissions ◽  
Value Chain ◽  
Large Scale ◽  
New Technology ◽  
Co2 Reduction ◽  
Road Transport ◽  
Transport Sector ◽  
Long Distance ◽  
Production Of Hydrogen

Achieving the CO2 reduction targets for 2050 requires extensive measures being undertaken in all sectors. In contrast to energy generation, the transport sector has not yet been able to achieve a substantive reduction in CO2 emissions. Measures for the ever more pressing reduction in CO2 emissions from transportation include the increased use of electric vehicles powered by batteries or fuel cells. The use of fuel cells requires the production of hydrogen and the establishment of a corresponding hydrogen production system and associated infrastructure. Synthetic fuels made using carbon dioxide and sustainably-produced hydrogen can be used in the existing infrastructure and will reach the extant vehicle fleet in the medium term. All three options require a major expansion of the generation capacities for renewable electricity. Moreover, various options for road freight transport with light duty vehicles (LDVs) and heavy duty vehicles (HDVs) are analyzed and compared. In addition to efficiency throughout the entire value chain, well-to-wheel efficiency and also other aspects play an important role in this comparison. These include: (a) the possibility of large-scale energy storage in the sense of so-called ‘sector coupling’, which is offered only by hydrogen and synthetic energy sources; (b) the use of the existing fueling station infrastructure and the applicability of the new technology on the existing fleet; (c) fulfilling the power and range requirements of the long-distance road transport.

Economic optimization of microgrids based on peak shaving and CO2 reduction effect: A case study in Japan

2021 ◽  
pp. 128973
Author(s):  
Liting Zhang ◽  
Yongwen Yang ◽  
Qifen Li ◽  
Weijun Gao ◽  
Fanyue Qian ◽  
...  
Keyword(s):  
Co2 Reduction ◽  
Economic Optimization ◽  
Peak Shaving ◽  
Reduction Effect
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