• Title/Summary/Keyword: Machine heating

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공동주택 기계실 난방설비 운전 개선 연구 (A Study on Improved Operation of Apartment Heating System in a Machine Room)

  • 서정아;신영기;김용기;이태원
    • 설비공학논문집
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    • 제29권1호
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    • pp.38-42
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    • 2017
  • This study proposes an idea for energy saving in apartment machine rooms. A conventional district heating system is equipped with constant-flow pumps and bypass valves to regulate pump differential pressure. Each family unit is equipped with a constant-flow on/off valve. This leads to excessive hot water circulation and a high return temperature. To reduce energy loss, this study assumes that each family unit is renovated with a heating valve which regulates the return temperature at $35^{\circ}C$. The hot water supply pump is also replaced with a pump with an inverter to vary flow rate. Expected energy savings is then estimated from field test data. According to the results, pump electricity consumption was reduced by 6,100 kWh for a family unit building over about half a year. The supply temperature can also be lowered by $5^{\circ}C$, which can contribute to a production of electricity of 10.3 kWh/ton of hot water.

전기발열시트 표면가열 양생공법의 현장적용 연구 (An Experimental Study on the Application in-situ of Curing Method by Planar Surface Heater for Cold Weather Concreting)

  • 김형래;조호규;김찬수;지남용
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2003년도 학술.기술논문발표회
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    • pp.19-22
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    • 2003
  • The purpose of this study is to analyze the curing effect of planar surface heater for concreting in cold weather. Some experiments were conducted to evaluate the temperature history of concrete structures cured with heating sheets. Results are as follows ; (1) The temperature of concrete showed continuously rising trend with the heating by planar surface heater under the cold environmental condition of 3~-12$^{\circ}C$. And after about 24 hours the maximum temperature of concrete was reached at 25~3$0^{\circ}C$. (2) The temperature of slab concrete heated by planar surface heater of 130W/$m^2$ was at least $25^{\circ}C$ higher than that of an exterior air, and the curing performance was much more effective than heating by hot wind machine. (3) Through the curing by planar surface heater for 48 hours, the concrete maturity of about 1.5 times to heating by hot wind machine was acquired.

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Flexible Flat Cable 생산성 향상을 위한 가압용 히팅롤러의 온도제어개선 (Temperature Control Improvement of Pressure Heating Roller for Flexible Flat Cable Production)

  • 김재학;이호중;전경진
    • 한국정밀공학회지
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    • 제22권7호
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    • pp.155-163
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    • 2005
  • Pressure heating rollers with temperature control were mounted to a flat cable laminating machine (FCLM). Pressure heating rollers should be heated up to the setting temperature $(175^{\circ}C)$ and kept on to producing good quality flexible flat cables (FFC). Existing Pressure heating rollers took more than 70minutes to the setting temperature and did not keep on the setting temperature in production. Temperature controller, electric power controller, material and diameter of rollers and heat capacities were changed to improve the temperature control of the pressure heat rollers for better production of the FFC. Thus, the reaching time to the setting temperature (RT), temperature stability time (TST) and temperature hunting (TH) were measured and compared with the existing pressure rollers case. The RT of A roller was shortened by 50minutes, and B roller was shortened by 15minutes. The TST of A roller was shortened by 13minutes, and B roller was shortened by 15minutes. The THs of both A and B rollers were settled up to ${\pm}5^{\circ}C$. Finally, the productivity of the FCLM and the quality of the FFC were increased.

고온가열을 받은 고강도 콘크리트의 역학적 특성에 관한 실험적 연구 (An Experimental Study on the Mechanical Properties of High Strength of High Strength Concrete Subject to High Temperature Heating)

  • 이태규;신승봉;김영선;이승훈;김규용;김무한
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2007년도 춘계학술논문 발표대회
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    • pp.9-12
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    • 2007
  • Recently, research and development related to high strength concrete for the high rise and large scale reinforced concrete building has been actively promoted in worldwide by national and private research project. But, it is reported that violent explosive explosion would be happened when it was exposed in fire. In the existed study, a explosion in a reinforced concrete structure looses the organism by the different contraction and expansion of hardened cement paste and aggregate, and causes crack by thermal stress. In case of the Europe, Japan and America, they have studied the explosion for a long time. However it would hardly study the explosion in domestic, So it is needed base on mechanical properties of fire deterioration in high strength concrete. Therefore, this study is intend as an mechanical properties of specimen to high heating by heating and load test machine and $700^{\circ}C$. As a result, it is willing to propose fundamental data for quick and accurate diagnosis of deteriorated concrete structure by fire damage with experiment according to the design high strength concrete.

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농업용 난방기의 사용 연식에 따른 이산화탄소 배출농도 비교 (Comparison of Carbon Dioxide Emission Concentration according to the Age of Agricultural Heating Machine)

  • 김나은;김대현;김연중;김현태
    • 생물환경조절학회지
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    • 제32권3호
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    • pp.190-196
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    • 2023
  • 본 연구는 등유를 사용하는 농업용 난방기에서 배출되는 가스를 포집하고, 농업용 난방기의 사용 연식에 따른 이산화탄소의 배출농도를 파악하고자 수행되었다. 선형 회귀분석의 결과로 농업용 난방기의 연식에 따른 이산화탄소의 배출량은 R2 = 0.84로 y = 26.99x+721.98의 식을 따른다고 나타났다. 농업용 난방기의 사용 연식에 따라 세 그룹으로 분류하여 분산분석을 수행하였다. 분산분석을 수행한 결과, 분석을 위해 설정한 유의확률0.05보다 작은 2.1961×10-13으로 나타났으며 이는 적어도 한 그룹에서 차이가 나타난다는 것을 의미한다. 본 연구에서는 농업용 난방기의 기본적인 배출농도의 차이를 분석하고자 기기의 제작사와 상관없이 농업용 난방기의 기기 연식만을 고려하여 배출가스 데이터를 수집하였다. 기기의 연소 방식에는 제작사에 따라 연소 방식에 차이가 미미하게 있었을 것으로 판단되며 데이터 변수의 개수가 늘어난다면, SVR(support vector regression) 기반의 선형회귀 분석 등을 실시하여 농업용 난방기의 이산화탄소 데이터가 온실가스발생량 파악에 더욱 활용도가 높아질 것으로 판단된다. 추후 연구에서는 더욱 세분화된 데이터의 수집 방식을 따라 더욱 높은 정확도를 가진 결과값을 도출할 수 있다고 판단된다. 이처럼 우리나라의 농업 분야에서 용도별 온실가스 발생량을 조사하기 위하여 고정형 농기계인 농업용 난방기의 이산화탄소 발생량을 정확히 파악하여 온실가스 배출량 조사에 활용할 수 있을 것으로 판단된다.

윤활제 함침 나일론과 금속의 접합특성 (Joint Characteristics of Lubricant-Impregnated Nylon and Metals)

  • 장윤상;강석춘;호광일
    • 한국기계가공학회지
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    • 제2권3호
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    • pp.84-89
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    • 2003
  • The joint method and characteristics of lubricant Impregnated MC nylon and metal are analyzed. Considering the productivity and economics, two materials are Joined with the process of turning, knurling, and induction heating. The Joint strength is determined by adhesion of the melted nylon, the size of knurl, and the interference from the difference of the diameters. The parameters affecting induction heating process are analyzed. The adhesion strength of the melted nylon is measured. Finally the joint strength is analyzed in the environments of low, room, and high temperature. The nylon/metal Joined material is expected to be widely used as the sliding machine elements with good friction and shear strength.

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비재하 가열시험 및 Stub 시험체를 활용한 CFT기둥의 역학적 특성평가에 관한 실험적 연구 (An Experimental Study on the Evaluation of Mechanical Properties of CFT Column by Unstressed Test and Stub Specimen)

  • 이대희;이태규;이의배;김영선;김규용;김무한
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2008년도 춘계 학술논문 발표대회
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    • pp.209-213
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    • 2008
  • Recently, it increases in use of CFT(Concrete filled steel tube, below CFT) because material and method are required to be diversification and High-Performance according to increase the super-high structure. But, CFT column lose bearing capacity under fire because steel tube is exposed to outside. As a result, structure is collapsed and then it cause much damage. In case of the Europe, Japan and America, they have studied the fire-resistance performance of CFT under fire for a long time. However, it would have hardly studied it in domestic because it is much difficulty about experiment machine and cost. So it is needed base on fire-resist performance of CFT under fire. Therefore, this study dynamic specificity of stub column which made tester of stub column based on facts of strength and mixing fiber evaluated used heating and load testing machine. As a result, it is willing to propose fundamental data for quick and accurate diagnosis of deteriorated concrete structure by fire damage with experiment according to the design high strength concrete.

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나일론/금속 접합 마찰기계요소의 접합특성 (Joint Characteristics of the Nylon/Metal Sliding Machine Elements)

  • 장윤상
    • 한국정밀공학회지
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    • 제20권3호
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    • pp.125-132
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    • 2003
  • The joint method and characteristics of MC nylon and metal are analyzed. Considering the productivity and economics, two materials are joined with the process of turning, knurling, and induction heating. The joint strength is determined by adhesion of the melted nylon, the size of knurl, and the interference from the difference of the diameters. The adhesion strength of the melted nylon is measured. The effects of the knurl size and diameter difference are analyzed with the statistical methods. Finally the joint strength is analyzed in the environments of low, room, and high temperature. Based on this study, the nylon/metal material is expected to be widely used as the sliding machine elements with good lubrication and strength properties.

Reduced LS-SVM을 이용한 지역난방 동절기 공동주택 난방부하의 모델링 (Modeling of Winter Time Apartment Heating Load in District Heating System Using Reduced LS-SVM)

  • 박영칠
    • 설비공학논문집
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    • 제27권6호
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    • pp.283-292
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    • 2015
  • A model of apartment heating load in a district heating system could be useful in the management and utilization of energy resources, since it could predict energy usage and so could assist in the efficient use of energy resources. The heating load in a district heating system varies in a highly nonlinear manner and is subject to many different factors, such as heating area, number of people living in that complex, and ambient temperature. Thus there are few published papers with accurate models of heating load, especially in domestic literature. This work is concerned with the modeling of apartment heating load in a district heating system in winter, using the reduced least square support vector machine (LS-SVM), and with the purpose of using the model to predict heating energy usage in domestic city area. We collected 23,856 pieces of data on heating energy usage over a 12-week period in winter, from 12 heat exchangers in five apartments. Half of the collected data were used to construct the heating load model, and the other half were used to test the model's accuracy. The model was able to predict the heating energy usage pattern rather accurately. It could also estimate the usage of heating energy within of mean absolute percentage error. This implies that the model prediction accuracy needs to be improved further, but it still could be considered as an acceptable model if we consider the nonlinearity and uncertainty of apartment heating energy usage in a district heating system.

멜라민시트 적층 MDF 마루판재의 가열에 의한 치수변화 (Dimensional Change of Melamine Sheet Laminated MDF Flooring by Heating)

  • 민일홍;김의식;한규성
    • Journal of the Korean Wood Science and Technology
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    • 제24권4호
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    • pp.32-39
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    • 1996
  • The overall purpose of this study was to investigate the dimensional changes of melamine sheet laminated medium density fiberboard(MDF) floorings by sub-heating system(Ondol). This study was also conducted to improve the properties of melamine sheet laminated MDF floorings. The effects of density, resin content, manufacturing speed of MDF and types of melamine sheet on dimensional and weight changes of floorings were investigated. The results were as followings. 1. Dimensional and weight change of melamine sheet laminated MDF flooring by heating decreased with decreasing the density of MDF. 2. Dimensional and weight change of melamine sheet laminated MDF flooring by heating decreased with increasing the resin content of MDF. 3. Dimensional and weight change of melamine sheet laminated MDF flooring by heating decreased with decreasing the manufacturing speed of MDF. 4. Dimensional change of melamine sheet laminated MDF flooring in width direction by heating was doubled than that in machine direction. 5. Dimensional change and curling of high pressure melamine laminate(HPM) laminated MDF flooring by heating was less than those of low pressure melamine laminate(LPL) flooring. 6. Weight loss of melamine sheet laminated MDF flooring by heating has linear relationship with shrinkage.

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