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Review of technologies for snow melting systems
Kwesi Mensah,최종민 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.12
Precipitation is liquid or solid water falling from clouds to the Earth’s surface. Snow is a solid precipitation in the form of ice crystals. Due to many serious problems associated with snow accumulations during winter season, the removal of snow in winter seasons, is notonly a convenience, but can as well enhance safety and prevent property damage. Residential, commercial and industrial applications ofsnow melting have gained widespread acceptance. This paper reviews the researches on snow melting systems. The most researched andcurrently used snow melting systems are hydronic, electric and infrared systems. The review showed that hydronic snow melting systemsis the most used system currently. This was observed as a result of the availability of choice of energy source options. However, the hydronicsnow melting system has long payback period. One possible solution to compensate for this problem will be to combine snowmelting systems with HVAC systems. There have been many researches on snow melting systems for pavement and bridge applicationsexcept for roof. To help minimize the collapse of buildings as a result of heavy snowfall on roofs, roof snow melting needs more attention. The paper further reviews the concept of snow building loads by comparing standard codes like ISO 4355, ASCE 7-02 and SouthKorea’s code for calculating snow building loads. The snow building load calculated by ISO 4355 represented higher value than others. The paper also presented a review on factors such as snow density and snow water equivalents in details and describes their importancein the aspect of snow melting system design.
지열에너지와 재생열공급 모델 구축을 통한 탄소 중립 달성 전략
Kwesi Mensah,Selorm Kwaku Anka,Boafo Nicholas Lamptey,이광호(Kwang Ho Lee),최종민(Jong Min Choi) 한국신재생에너지학회 2021 한국신재생에너지학회 학술대회논문집 Vol.2021 No.7
지열원 히트펌프는 현존하는 최고효율의 냉난방시스템으로 연구개발 보급 및 확산의 중요성이 지속적으로 중요시되고 있다. 세계적으로 지구온난화 대응을 위하여 2050년 탄소중립 목표를 달성하기 위해 많은 노력을 경주하고 있다. 탄소중립을 위해 대한민국 정부는 에너지 공급 부문, 산업 부문, 수송 부문, 건물 부문, 폐기물 부문, 농축수산 부문과 흡수 부문에 대해 많은 노력을 경주하고 있다. 본 연구에서는 지열원 히트펌프 시스템을 통하여 건물 부문의 에너지 소비 저감을 통한 탄소 중립 기여도와 관련 정책 분석 및 수립에 관한 연구를 수행하였다. 이를 통해 지열원 히트펌프 시스템의 보급 확산을 통해 탄소 중립 목표 달성에 크게 기여할 수 있다는 결과를 도출하였으며, 에너지 공급 부문으로의 간접적인 효과도 매우 크다는 결과를 얻고 관련 정책을 제안하였다.
Study on the Thermal Stability of a Constant Temperature and Humidity Chamber
Kwesi Mensah,Samuel Boahen,Jong Min Choi 대한설비공학회 2018 대한설비공학회 학술발표대회논문집 Vol.2018 No.11
Modern climatic chambers for temperature and humidity simulations are operated over a wide range of environmental test conditions such as a temperature (-70 ℃ to 200 ℃) and a relative humidity (10% RH to 98%RH) for biological items and industrial products. The stability and fluctuation control of these thermal-environmental conditions are critical for the preservation of the test specimen and products. Even though climatic test chambers are found in many industries and companies, rare literature and data is found on the experimental investigation of the stability of these climatic test chambers. In this study, an experimental investigation on the possibility of minimizing fluctuations and ensuring stability, by the adoption of a variable speed compressor to the refrigerating unit of a 400-Liter temperature and humidity chamber is carried out. It is found that, adopting a variable speed compressor to the refrigeration unit has a significant potential to ensure stability of climatic chambers with an added advantage of energy savings for a given operating and surrounding conditions.
Peak and Annual Snow Load Pattern for Effective Snow Melting System Design in Republic of Korea
Kwesi Mensah,최종민 대한설비공학회 2015 International Journal of Air-Conditioning and Refr Vol.23 No.4
Snowstorm, slippery pedestrian walkways, ice and snow on pavement and roofs of structures continue to serve as a threat to life and infrastructure in many low temperature nations. Owing to these menaces coupled with an increase in the demand and cost of energy globally, engineers and planners are tasked to design effective and efficient green technologies to counterbalance these demands. Snow melting systems are gradually gaining widespread application in the areas of bridge, pavements and roofs of buildings. Snow melting loads are an integral part in the design of snow melting systems. This paper developed snow melting and roof snow building load for the Republic of Korea. Annual averages and frequency distribution methods were used in the analysis of a 10-year period weather data. Monthly total as well as peak snowfall rate values were used to generate annual and peak snow melting load values, respectively. It was observed that the annualaverage approach is more conservative for most climatic conditions than the frequency analysis method. Minimum flat roof snow building loads were presented to aid in the structural analysis of structures within the Republic of Korea. The developed database in this paper will provide the database for designing a snow melting system and for analyzing the building structural interpretation considering snow weight.
지중열교환기의 고밀도폴리에틸렌 배관 형상에 따른 열전달 성능 특성에 대한 수치해석적 연구
Kwesi Mensah,최종민(Jong Min Choi) 한국지열·수열에너지학회 2016 한국지열에너지학회논문집 Vol.12 No.4
A ground source heat pump (GSHP) system is recommended as a heating and cooling system to solve the pending energy problem in the field of air conditioning, because it has the highest efficiency. However, higher initial construction cost works as a barrier to the promotion and dissemination of GSHP system. In this study, numerical analysis on the characteristics of high density polyethylene (HDPE) pipe with spiral inside was executed. The heat transfer and flow characteristics of it were compared with those of a conventional smooth HDPE pipe. The heat transfer coefficient and pressure drop of the spiral HDPE pipe were higher than those of the smooth HDPE pipes at the same fluid flow rate. By decreasing the flow rate, the spiral HDPE pipe represented similar values of heat transfer coefficient and pressure drop to the smooth HDPE pipe. The lower flow rate of the spiral HDPE pipe comparing with it of the smooth HDPE pipe is estimated to reduce the length of the ground loop heat exchanger.