Energy Reduction Effect Research Articles

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

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.

Changes in Sand Budget for Littoral Cell after Coastal Improvement Project

Kim, I.H.; Kim, J.H.; Nam, J.M.; Chang, S.Y.; Cho, W.C.; Do, K.D.; Kim, Y.J.; Song, D.S., and Lee, H.S., 2020. Changes in sand budget for littoral cell after coastal improvement project. In: Malvarez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 242–246. Coconut Creek (Florida), ISSN 0749-0208.The Munam2 harbor was constructed in 1989 and the direction of Munam river mouth was changed from the Gyoam beach to the Backdo beach in order to prevent sediment deposit within the harbor inside. In order to reduce erosion damage at the Gyoam beach, the CIP started in March 2014, and three submerged breakwaters were constructed in September 2016, as well as the beach nourishment. Therefore, the characteristics of shoreline change and bathymetric change were analyzed due to wave transmission after the implementation of submerged breakwaters in littoral drift cell. The beach monitoring was performed twice annually from 2014 to 2018, that the surveying items were shoreline change, beach profile and bathymetric change, including two times wave field observation during the monitoring period. As a result, the wave transmission rate between the W-2 and W-3 shows that the function of submerged breakwater is working effectively only when a significant wave, height over 1.3 m, occurs. However, it was analyzed that there was no wave energy reduction effect as a submerged breakwater when the significant wave height is below 0.3 m. After the submerged breakwaters were constructed to solve the erosion problem, the stable coastal line was formed on the Gyoam beach.

Performance Evaluation of the Louver-type Double-skin Facade System using PCM Film for Cooling Energy Reduction

Purpose: There are problems with the construction method for liquid-type phase change materials (PCMs), and with the load generated in the melting process. The PCM film is thus used as a solution for enhancing stability and workability, reducing indoor cooling energy and PCM film installability. In this study, film applicability is considered; we propose a louver-type double skin system using PCM film, evaluate its performance in comparison with existing liquid-type PCMs, and confirm the installability of PCM film and the cooling energy reduction effect. Method: A total of four types of experimental bodies were manufactured for comparative analysis of thermal performance and temperature change. The experimental period was 4 days a week, the actual data measurement was performed every 12 h during the night and daytime, the results were compared and analyzed graphically, and the possibility of installing a louver-type double-hull system using PCM film was verified. The cooling energy reduction effect was also confirmed. Result: Although the liquid-type PCM had the best performance, its practical use in building materials was evaluated based on workability and stability. On the other hand, the performance of the PCM film was 11.66% lower than that of the liquid PCM, which was determined to be high. There will be need for further work on deriving the melting temperature using an appropriate PCM film, and controlling the sensible and latent heat effects to satisfy both the cooling and the heating effects.

Dietary Interventions for Night Shift Workers: A Literature Review.

(1) Background: Night shift workers have greater risks of developing cardiometabolic diseases compared to day workers due to poor sleep quality and dietary habits, exacerbated by circadian misalignment. Assessing effects of dietary interventions on health outcomes among this group will highlight gaps for future research. (2) Methods: A search of studies was conducted on PubMed, Cochrane Library, Embase, Embase Classic, Ovid Emcare, and Google Scholar, from earliest to June 2019. The population–intervention–comparator–outcomes–study design format determined inclusion criteria. (3) Results: 756 articles were retrieved; five met inclusion and exclusion criteria. Six-hundred-and-seventy night shift workers were from healthcare, industrial, and public safety industries. Dietary interventions included two longer-term nutrition programs and three shorter-term adjustments of meal composition, type, and timing. Outcome measures were varied but included weight and cardiometabolic health measures. Nutrition programs found no weight improvement at both six and 12 months; low-density lipoprotein (LDL)-cholesterol levels decreased at six months. Triglycerides peaked after meals at 7:30 pm; glucose and insulin area under the curve peaked after meals at 11:30 pm. (4) Conclusions: Weight loss was not achieved in the studies reviewed but LDL-cholesterol improved. Future studies should investigate the effects of energy reduction and altering meal timing on cardiometabolic risk factors of night shift workers in randomised controlled trials, while assessing hunger, sleepiness, and performance.

Feasibility Study on Variable-Speed Air Conditioner under Hot Climate based on Real-Scale Experiment and Energy Simulation

It is well known that inverter-driven variable-speed compressor (or inverter) air conditioners are more efficient than constant-speed compressor air conditioners. Therefore, most countries have employed part-load assessment test standards such as ISO 16358, EN 14825 and ASHRAE 116 in addition to the conventional ISO 5151 full-load test standard to appropriately evaluate the part-load efficiencies of variable-speed air conditioners. However, many countries in the Middle East and South America still use the ISO 5151 standard owing to policy or high- temperature environmental considerations. In this study, we experimentally verify the energy saving effect of the inverter air conditioner with respect to the constant-speed air conditioner under the Korean climate with distinct temperature changes of four seasons and under the hot climate of Saudi Arabia throughout the year. ISO 5151 defines test conditions for a single temperature, whereas ISO 16358, EN 14825 and ASHRAE 116 simulate seasonal efficiencies using interpolation of several climate test results. Herein, we directly employ the environmental changes during a day or season in a qualified test room with specific dimension. Using extensive regional and seasonal climate data for Saudi Arabia and South Korea, the changes in temperature conditions are applied directly to the outdoor side and appropriate building cooling load conditions are applied to the indoor side of the air-enthalpy-type test room. The energy savings of the inverter air conditioner were analyzed experimentally according to the spatial and temporal temperature changes. The energy reduction effects of the inverter air conditioner largely depended on the temperature and cooling load changes for a day or season. Furthermore, a feasibility study based on an energy simulation showed that the variable-speed air conditioner could be economical even in hot climates.

Impact of urban characteristics on cooling energy consumption before and after construction of an urban park: The case of Gyeongui line forest in Seoul

A change in the thermal environment of an urban area affects health, living conditions, and energy consumption. In urban planning, urban parks are one of the methods for improving the thermal environment and saving cooling energy. Urban park construction can mitigate temperature, but it also causes urban development by increasing local attractiveness. To achieve efficient energy saving through parks in urban planning, the purpose of this study is to investigate the relationship between building energy consumption and urban characteristics both before and after the construction of an urban park. This study targeted Seoul's Gyeongui line forest, which was recently converted into a linear park on the former railway as an urban regeneration project. We analyzed the relationship between energy consumption and urban characteristics using a regression model, focusing on the changes before and after the construction. In this study, urban characteristics include environment, building physical characteristics, and economic variables. The results show that the construction of the urban park reduced not only temperature but also building energy consumption. The energy reduction effect of the park was limited to a marginal distance. Meanwhile, the urban park construction caused land prices to rise and prompted new development, and this changed the urban characteristics of the area and affected energy consumption. Despite changes in urban characteristics, urban park planning is an effective methods of reducing the energy consumption involved in cooling urban areas. We recommend comprehensive consideration of the urban factors when making park policy to reduce urban temperature and energy consumption.

An experimental study on applying organic PCMs to gypsum-cement board for improving thermal performance of buildings in different climates

The main objective of this study was to develop a heat storage gypsum-cement board (G/C board) by using vacuum impregnation method and evaluate its physical and thermal properties. In particular, this paper analyzed the chemical property, heat capacity, thermal resistance, thermal conductivity, and heat transfer performance of the heat storage G/C board based on results of Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), TCi, and dynamic heat transfer analyses. Especially, dynamic heat transfer analysis was focused in this study to determine time-lag effect and thermal efficiency property of the developed heat storage G/C board with PCMs. As a result, it was confirmed that PCM containing heat storage G/C boards had time lag effect. Such heat storage G/C board could be used to reduce energy consumption of buildings. In the analysis of building energy consumption through energy simulation, the energy reduction effect is larger when the G/C board with n-octadecane was applied, because n-octadecane has more suitable phase change temperature. Especially, when n-octadecane was applied, it is effective to reduce the cooling load during cooling season.

Application of Thermal Labyrinth System to Reduce Heating and Cooling Energy Consumption

To reduce the energy consumption in buildings, modern buildings are increasingly becoming airtight. In these structures, the outdoor air is supplied inside through mechanical ventilation systems, which are essential for ensuring comfortable indoor air quality. However, these systems consume a considerable amount of energy in buildings. One potential solution is using a thermal labyrinth system, which is buried underneath the building. It can pre-cool or pre-heat the outdoor air through heat transfer with the surrounding soil. In this research, a number of case studies were conducted to optimize the thermal labyrinth design. The optimized thermal labyrinth system was derived using computational fluid dynamics (CFD) simulation. In addition, operation algorithms were developed for the efficient operation of the thermal labyrinth system in buildings. The results indicated that there were five operation modes, and the thermal labyrinth could be operated for seven months of the year. The energy reduction effects of the thermal labyrinth system were analyzed and were assessed by the transient system simulation (TRNSYS) tool. A 12% reduction in the annual heating and cooling energy was achieved by applying the thermal labyrinth system.

Energy utilisation of broiler chickens in response to guanidinoacetic acid supplementation in diets with various energy contents

This experiment was conducted to investigate the effects of guanidinoacetic acid (GAA) on productive performance, intestinal morphometric features, blood parameters and energy utilisation in broiler chickens. A total of 390 male broiler chicks (Ross 308) were assigned to six dietary treatments based on a factorial arrangement (2×3) across 1-15 and 15-35-d periods. Experimental treatments consisted of two basal diets with standard (STD; starter: 12·56 MJ/kg and grower: 12·97 MJ/kg) and reduction (LME; starter: 11·93 MJ/kg and grower: 12·33 MJ/kg) of apparent metabolisable energy (AME) requirement of broiler chickens each supplemented with 0, 0·6 and 1·2 g/kg GAA. Supplemental 1·2 g/kg GAA decreased the negative effects of feed energy reduction on weight gain across starter, growing and the entire production phases (P<0·05). Energy retention as fat and total energy retention were increased when birds received LME diets supplemented with 1·2 g/kg GAA (P<0·05). Net energy for production (NEp) and total heat production increased in birds fed LME diets containing 1·2 g/kg GAA (P<0·05). A significant correlation was observed between dietary NEp and weight gain of broilers (r 0·493; P=0·0055), whereas this relationship was not seen with AME. Jejunal villus height and crypt depth were lower in birds fed LME diets (P<0·05). Serum concentration of creatinine increased in broilers fed LME diets either supplemented with 1·2 g/kg GAA or without GAA supplementation (P<0·05). Supplemental GAA improved performance of chickens fed LME diet possibly through enhanced dietary NEp. The NEp could be preferred over the AME to assess response of broiler chickens to dietary GAA supplementation.

Verification of Energy Reduction Effect through Control Optimization of Supply Air Temperature in VRF-OAP System

This paper developed an algorithm that controls the supply air temperature in the variable refrigerant flow (VRF), outdoor air processing unit (OAP) system, according to indoor and outdoor temperature and humidity, and verified the effects after applying the algorithm to real buildings. The VRF-OAP system refers to a heating, ventilation, and air conditioning (HVAC) system to complement a ventilation function, which is not provided in the VRF system. It is a system that supplies air indoors by heat treatment of outdoor air through the OAP, as a number of indoor units and OAPs are connected to the outdoor unit in the VRF system simultaneously. This paper conducted experiments with regard to changes in efficiency and the cooling capabilities of each unit and system according to supply air temperature in the OAP using a multicalorimeter. Based on these results, an algorithm that controlled the temperature of the supply air in the OAP was developed considering indoor and outdoor temperatures and humidity. The algorithm was applied in the test building to verify the effects of energy reduction and the effects on indoor temperature and humidity. Loads were changed by adjusting the number of conditioned rooms to verify the effect of the algorithm according to various load conditions. In the field test results, the energy reduction effect was approximately 15–17% at a 100% load, and 4–20% at a 75% load. However, no significant effects were shown at a 50% load. The indoor temperature and humidity reached a comfortable level.

Energy Reduction Effect of the South-to-North Water Diversion Project in China

The North China Plain, with a population of approximately 150 million, is facing severe water scarcity. The over-exploitation of groundwater in the region, with accumulation amounts reaching more than 150 billion m3, causes a series of hydrological and geological problems together with the consumption of a significant amount of energy. Here, we highlight the energy and greenhouse gas-related environmental co-benefits of the South-to-North Water Diversion Project (SNWDP). Moreover, we evaluate the energy-saving effect of SNWDP on groundwater exploitation based on the groundwater-exploitation reduction program implemented by the Chinese government. Our results show that the transferred water will replace about 2.97 billion m3 of exploited groundwater in the water reception area by 2020 and hence reduce energy consumption by 931 million kWh. Further, by 2030, 6.44 billion m3 of groundwater, which accounts for 27% of the current groundwater withdrawal, will save approximately 7% of Beijing’s current thermal power generation output.

生活スタイルの変化による住宅におけるエネルギー削減効果の研究 （第3報）生活スタイルを考慮した室内温熱環境評価

生活スタイルの変化による住宅におけるエネルギー削減効果の研究 （第3報）生活スタイルを考慮した室内温熱環境評価

生活スタイルの変化による住宅におけるエネルギー削減効果の研究 （第2報）省エネ手法導入による効果検証

生活スタイルの変化による住宅におけるエネルギー削減効果の研究 （第2報）省エネ手法導入による効果検証

Technological assessment of residential fuel cells using hydrogen supply systems for fuel cell vehicles

Widespread of the fuel cell vehicles (FCV) is one of the essential solutions to CO2 emission mitigation. However there were only 81 working hydrogen stations distributed in Japan in January 2017. Therefore, it has become increasingly necessary to establish the hydrogen stations. In this study, we focus on the unutilized hydrogen production capacity of a fuel processor system (FPS) incorporated in a residential fuel cell cogeneration system. We proposed a system which the FPS and fuel cell stacks are operated independently at their respective efficient load factors, and which can produce hydrogen for the FCV using the unutilized capabilities of the FPS. An optimum scheduling model for the operation of the FPS and the fuel cell stacks was developed to evaluate annual hydrogen production for the FCV for 24 households. As the results, it was found that all households have the capacity to produce at least 1,040 Nm3/year of hydrogen, which a FCV can run 8,000 km in a year. Furthermore, we evaluated the primary energy reduction potential were in relation to the different power and hot water demands. As the results, it was found that the primary energy reduction effect slightly increases with increasing hydrogen supply up to about 8,000 km worth of FCV hydrogen.

System effects of primary energy reduction connected with operation of the CHP plants

AbstractThe paper is devoted to explication of one of the advantages of heat and electricity cogeneration, rarely considered in technical literature. Usually attention is paid to the fact that heat losses of the heat distribution network are less severe in the case of cogeneration of heat in comparison with its separate production. But this conclusion is also true in other cases when the internal consumption of heat is significant. In this paper it has been proved in the case of two examples concerning trigeneration technology with an absorption chiller cooperating with a combined heat and power (CHP) plant and CHP plant integrated with amine post-combustion CO2processing unit. In both considered cases it might be said that thanks to cogeneration we have to do with less severe consequences of significant demand of heat for internal purposes.

Cooling energy reduction effect of parallel double-window system operation in residential buildings in South Korea

This paper aims to derive the operational modes of a parallel double-window system that reduces cooling energy consumption and satisfies indoor comfort through natural ventilation. The parallel double-window system examined in this paper is a window system that could control indoor draft distribution and adjust the size of the opening depending on indoor and outdoor conditions. The system can be used in five ways (all close, out-open + in close, out-open+in open (tilt), out-open+in open (turn) and all open). This work verified the energy savings and indoor comfort of the existing mode experimentally, which were originally derived based on simple calculations at the time when the parallel double-window system was developed. A new operation mode, Alt 1, was derived, which addressed problems of the existing mode. In addition, in this work, the operation mode Alt 2 was derived, which simplified Alt 1 so that the actual occupant can use the system easily. By measuring these three operation modes and comparing the results with those of energy plus simulations, the work derived the amount of cooling energy savings and the level of indoor comfort through the use of an appropriate operation mode during inter-seasonal periods. Compared to when the natural ventilation operation mode was not used, cooling energy consumption was reduced by 60% when the operation mode was in use. The cooling temperature set point could have a significant impact on cooling energy consumption.

生活スタイルの変化による住宅におけるエネルギー削減効果の研究 （第５報）室内温熱環境改善効果の検証

生活スタイルの変化による住宅におけるエネルギー削減効果の研究 （第５報）室内温熱環境改善効果の検証

生活スタイルの変化による住宅におけるエネルギー削減効果の研究 (第4報)エネルギー消費量削減効果の検証

生活スタイルの変化による住宅におけるエネルギー削減効果の研究 (第4報)エネルギー消費量削減効果の検証

옥상녹화에 따른 공동주택 에너지 저감효과 분석 연구

옥상녹화에 따른 공동주택 에너지 저감효과 분석 연구

신 흡수제(KoSol-5)를 적용한 0.1 MW급 Test Bed CO2포집 성능시험

한전 전력연구원에서 개발한 고효율 아민계 습식 <TEX>$CO_2$</TEX> 흡수제(KoSol-5)를 적용하여 0.1 MW급 Test Bed <TEX>$CO_2$</TEX> 포집 성능시험을 수행하였다. 500 MW급 석탄화력발전소에서 발생되는 연소 배가스를 적용하여 하루 2톤의 <TEX>$CO_2$</TEX>를 처리할 수 있는 연소 후 <TEX>$CO_2$</TEX> 포집기술의 성능을 확인하였으며 또한 국내에서는 유일하게 재생에너지 소비량을 실험적으로 측정함으로써 KoSol-5 흡수제의 성능에 대한 신뢰성 있는 데이터를 제시하고자 하였다. 그리고 주요 공정변수 운전 및 흡수탑 인터쿨링 효율 향상에 따른 에너지 저감 효과를 테스트하였다. 흡수탑에서의 <TEX>$CO_2$</TEX> 제거율은 국제에너지기구 산하 온실가스 프로그램(IEA-GHG)에서 제시하는 <TEX>$CO_2$</TEX> 포집기술 성능평가 기준치(<TEX>$CO_2$</TEX> 제거율: 90%)를 안정적으로 유지하였다. 또한 흡수제(KoSol-5)의 재생을 위한 스팀 사용량(재생에너지)은 <TEX>$2.95GJ/tonCO_2$</TEX>가 소비되는 것으로 산출되었는데 이는 기존 상용 흡수제(MEA, Monoethanol amine)의 평균 재생에너지 수준(약 <TEX>$4.0GJ/tonCO_2$</TEX>) 대비 약 26% 저감 된 수치이다. 본 연구를 통해 한전 전력연구원에서 개발한 KoSol-5 흡수제 및 <TEX>$CO_2$</TEX> 포집 공정의 우수한 <TEX>$CO_2$</TEX> 포집 성능을 확인할 수 있었고, 향후 본 연구에서 성능이 확인된 고효율 흡수제(KoSol-5)를 실증급 <TEX>$CO_2$</TEX> 포집플랜트에 적용할 경우 <TEX>$CO_2$</TEX> 포집비용을 크게 낮출 수 있을 것으로 기대된다. The absorption efficiency of amine <TEX>$CO_2$</TEX> absorbent (KoSol-5) developed by KEPCO research institute was evaluated using a 0.1 MW test bed. The performance of post-combustion technology to capture two tons of <TEX>$CO_2$</TEX> per day from a slipstream of the flue gas from a 500 MW coal-fired power station was first confirmed in Korea. Also the analysis of the absorbent regeneration energy was conducted to suggest the reliable data for the KoSol-5 absorbent performance. And we tested energy reduction effects by improving the absorption tower inter-cooling system. Overall results showed that the <TEX>$CO_2$</TEX> removal rate met the technical guideline (<TEX>$CO_2$</TEX> removal rate : 90%) suggested by IEA-GHG. Also the regeneration energy of the KoSol-5 showed about <TEX>$3.05GJ/tonCO_2$</TEX> which was about 25% reduction in the regeneration energy compared to that of using the commercial absorbent MEA (Monoethanolamine). Based on current experiments, the KoSol-5 absorbent showed high efficiency for <TEX>$CO_2$</TEX> capture. It is expected that the application of KoSol-5 to commercial scale <TEX>$CO_2$</TEX> capture plants could dramatically reduce <TEX>$CO_2$</TEX> capture costs.