창호 에너지소비효율등급제에 따른 공동주택의 열성능 평가

임희원,김동윤,이수만,안정혁,윤종호,신우철 대한설비공학회 2018 설비공학 논문집 Vol.30 No.4

The Korean fenestration energy consumption efficiency rating system only considers thermal performance of the heat transfer coefficient (U-value) and airtightness excluding optical characteristics of the solar heat gain coefficient (SHGC). This study analyzed annual heating and cooling energy requirements on the middle floor of apartment by optical and thermal performance of windows to evaluate the suitability of the rating system. One hundred and twenty-eight windows were analyzed using THERM and WINDOW 7.4, and energy simulation for a reference model of an apartment house facing south was performed using TRNSYS 17. The results showed that window performance was the main factor in the heating and cooling load. The heating load of the reference model was 539 kWh to 2,022 kW, and the cooling load was 376 kWh to 1,443 kWh. The coefficient of determination (R2) of the heating and cooling loads driven from the SHGC were 0.7437 and 0.9869, which are more compatible than those from the U-value, 0.0558 and 0.4781. Therefore, it is not reasonable to evaluate the energy performance of windows using only the U-value, and the Korean fenestration energy consumption efficiency rating system requires a new evaluation standard, including SHGC.

Energy Efficiency of Fluidized Bed Drying for Wood Particles

Yonggun Park,Yoon Seong Chang,Jun Ho Park,Sang Yun Yang,Hyunwoo Chung,Soo Kyeong Jang,In Gyu Choi,Hwanmyeong Yeo 한국목재공학회 2016 목재공학 Vol.44 No.6

This study evaluates the economic feasibility of industrializing fluidized bed dryer for wood particles. The theoretically required heat energy and energy efficiency were evaluated using a pilot scale fluidized bed dryer. When Mongolian Oak wood particles with 50% initial moisture content were dried in the fluidized bed dryer with air of 70℃ air circulating at 1.1-1.3 m/s for 30 minutes, the total theoretically required heat energy was 2,177 kJ. Of this, 1,763 kJ (approximately 81.0%) was used to heat the air flowing in from outside the dryer and 386 kJ (approximately 17.7%) was used to heat and remove water from the wood particles. Actual energy consumed was 7,560 kJ, giving energy efficiency of 28.8%. Thus, to industrialize a drying method such as fluidized bed drying, where the dryer volume is significantly larger than the volume of wood particles, it is necessary to minimize energy loss and maximize energy efficiency by designing the dryer size considering the amount of wood particles and choosing a suitable air circulation rate.

심각한 열스트레스에 의한 육성기 거세한우의 사료 소화율 변화 탐색 및 유지를 위한 에너지 요구량 설정 연구

조유경,최성호,한옥규,박정현,최창원 경상대학교 농업생명과학연구원 2016 농업생명과학연구 Vol.50 No.5

우리는 심각한 열스트레스 및 서로 다른 사료 에너지 급여가 사료 소화율 변화에 미치는 영향과 심각 한 열스트레스 조건에서 유지를 위한 에너지 요구량을 설정하기 위해 한우 육성기 거세우 4두(평균체중 200±11.7kg)를 이용하였다. 사료 처리는 서로 다른 에너지 공급을 위해 4 시험구(TDN 기준, 쾌적한 상태 하에서 한국사양표준 한우 육성우 에너지 요구량의 100%(대조구), 심각한 열스트레스 하에서 에너 지 100%(E100), 115%(E115), 130%(E130)로 나누어 4×4 라틴 방각법으로 수행하였다. 온도 및 습도에 노출한 열스트레스 조건을 위해 대조구는 쾌적한 온습도지수(THI)=71.5, 나머지 3개 처리구는 THI=81.4로 심각한 스트레스 수준으로 설정하였다. 심각한 열스트레스는 진정 건물소화율을 유의적으 로(p<0.05) 감소시켰으며(대조구 81.5 vs E100 79.1, E115 77.0 및 E130 76.0%), 사료에너지 공급 수 준의 증가는 건물소화율의 감소를 가져오는 것으로 나타났다. 심각한 열스트레스 및 서로 다른 사료 에 너지 급여 수준은 혈중 생리대사물질 함량 및 체온 변화에 유의적인 영향을 미치진 않았다(p>0.05). 본 연구를 통해 심각한 열스트레스 하에서 육성기 한우거세우의 유지를 위한 에너지 요구량은 Y=0.235X+115.03과 같은 산정식으로 계산될 수 있으며, 이러한 결과는 육성기 한우거세우에게 열스트 레스 하에서 체중변화없는 유지 에너지 요구량을 만족시키기 위해서는 현재 한국사양표준 대비, 사료 에너지 15.03%를 더 공급해야 할 것으로 판단된다. Four growing Hanwoo cattle weighing 200±11.7kg were used within 4×4 Latin square design to establish nutrient requirements for Hanwoo growing steers under severe heat stress. The steers were fed four different energy level diets; 100%(control), 100%(E100), 115%(E115) and 130%(E130) of energy levels of growing Hanwoo steers based on total digestible nutrient level suggested by the Korea Feeding Standard for Hanwoo using timothy hay and commercial concentrate. The steers in the control were housed with no stress, whereas the steers in the other groups were under severe heat stress. The severe heat stress significantly decreased(p<0.05) true digestibility of dry matter(i.e. control 81.5% vs E100 79.1, E115 77.0 and E130 76.0, respectively). The severe heat stress and different energy intake levels did not affect blood physiological metabolites and body temperature of the growing steers. Based on changes in average daily gain by different energy intake level, the equation(Y=0.235X+115.03) of energy requirement of growing Hanwoo steers without changes in body weight was calculated, indicating that, compared with the present energy intake suggested by Korean feeding standard, 15.03% of dietary energy for maintenance of growing Hanwoo steers under severe heat stress should be increased.

사무소 건물의 창호에너지소비효율등급제 적용성 평가

이수만(Soo Man Lee),김동윤(Dong Yun Kim),안정혁(Jung Hyuk An),이철성(Cheol Seng Lee),신우철(U Cheul Shin) 대한설비공학회 2019 설비공학 논문집 Vol.31 No.10

In this study, we analyzed the annual heating and cooling energy requirements of reference building with 97 certificated windows using TRNSYS 17, to review the applicability of the “Window Energy Consumption Efficiency Rating System” to the office building. The analyzed model was a medium-size office building with lightweight curtain walls and a window-to-wall ratio of 52%. The results are as follow : First, the annual total thermal load was 60,261 to 111,616 kWh and the ratio of heating load to cooling load was 1:9 showing that cooling was the main factor of the thermal load. Second, the total thermal load by SHGC showing an almost perfect linear relationship. The F-test significance probability in the regression model was 0.000 meaning statistical significance and the coefficient of determination was 0.9656 showing high correlation. In contrast, the F-test significance probability in the regression model by U-value was 0.00484 showing statistical significance but the coefficient of determination was 0.0805 showing low correlation. Third, the SHGC of window was the main factor of the total thermal load in the office building. It showed the limitation of subject in “Window Energy Consumption Efficiency Rating System” which was limited to insulation performance and airtight performance. Thus, in to evaluate the window sets in terms of energy saving, the “Window Energy Consumption Efficiency Rating System” with SHGC should be considered.

Estimation of the net energy requirement for maintenance in broilers

Wei Liu,Chang Hua Lin,Zheng Ke Wu,Guo Hua Liu,Hai Jie Yan,Hua Ming Yang,Hui Yi Cai 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.6

Objective: The net energy requirement for the maintenance (NEm) of broilers was determined using regression models by the indirect calorimetry method (ICM) or the comparative slaughter method (CSM). Methods: A 2×4 factorial arrangement of treatments including the evaluation method (ICM or CSM) and feed intake (25%, 50%, 75%, or 100% of ad libitum recommended) was employed in this experiment. In the ICM, 96 male Arbor Acres (AA) birds aged d 15 were used with 4 birds per replicate and 6 replicates in each treatment. In the CSM, 116 male AA birds aged d 15 were used. Among these 116 birds, 20 were selected as for initial data and 96 were assigned to 4 treatments with 6 replicate cages and 4 birds each. The linear regression between retained energy (RE) and metabolizable energy intake (MEI) or the logarithmic regression between heat production (HP) and MEI were used to calculate the metabolizable or net energy requirement for maintenance (MEm) or NEm, respectively. Results: The evaluation method did not detect any differences in the metabolizable energy (ME), net energy (NE), and NE:ME of diet, and in the MEI, HP, and RE of broilers. The MEI, HP, and RE of broilers decreased (p<0.01) as the feed intake decreased. No evaluation method× feed intake interaction was observed on these parameters. The MEm and NEm estimated from the linear relationship were 594 and 386 kJ/kg of body weight (BW)0.75/d in the ICM, and 618 and 404 kJ/kg of BW0.75/d in the CSM, respectively. The MEm and NEm estimated by logarithmic regression were 607 and 448 kJ/kg of BW0.75/d in the ICM, and were 619 and 462 kJ/kg of BW0.75/d in the CSM, respectively. Conclusion: The NEm values obtained in this study provide references for estimating the NE values of broiler diets.

커튼월(Curtain-wall)공법 공동주택의 최적 창호 성능 평가

김지현(Ji-Hyeon Kim),최현식(Hyun-Sik Choi),임희원(Hee-Won Lim),신우철(U-Cheul Shin) 한국태양에너지학회 2020 한국태양에너지학회 학술대회논문집 Vol.2020 No.10