Hybrid 히트펌프의 성능 및 중요인자에 관한 연구

박성룡(SeongRyong Park),백영진(YoungJin Baik),장기창(KiChang Chang),나호상(Hosang Rha),Huaizhang Tian 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.11

The utilization of unused energy is important because it can afford to offer a chance to increase energy efficiency of a heat pump system. Especially the waste energy recovery by heat pump can be easily utilized in industrial field for processing water supply system. In this article, the efficient way to make a high temperature water by using the waste water as heat source. This article concerns such a cycle that its system making up has the features: a two-stage compression, a two stage expansion and two desorbers, each of which being located after an expansion valve. By comparisons of the performance with those of common two-stage compression and single expansion CAHP systems for four heating cases, the simulation studies showed that the new system has superior performance, under the working conditions of lower compressor outlet temperature and lower maximum system pressure, which is very important for the components of the system to be operated safely. And the performance can be improved further by optimum displacements of the compressors chosen. The simulations also demonstrated how changes of the sink temperature glide, maximum pressure and the performance of the system were adjusted by the circulation rate and the ammonia concentration for a given heat.

텍스트마이닝 분석을 통한 공간의 의미 표출에 관한 연구 - 교량 자살 빅데이터를 중심으로 -

박변갑 ( Park Byeongap ),박성룡 ( Park Seongryong ) 한국공간디자인학회 2021 한국공간디자인학회논문집 Vol.16 No.8

(연구배경 및 목적) 본 연구의 목적은 공간 인식 과정에서 표출된 언어를 통해 공간에서 일어난 사건과 언어의 관계 맺음을 살펴보는 것이다. 연구자는 이를 위한 실증연구 대상으로 ‘교량’이라는 공공공간에서 일어나는 자살사건에 주목했다. 한국의 높은 자살률은 오래된 사회 문제 중 하나이다. 그간의 자살 관련 연구는 개인의 사적 공간이나 심리적 요인에 관한 것에 집중되어 있고, 공공공간을 대상으로 한 자살 연구는 미비하다. 본 연구에서는 자살사건이 빈번하게 발생하는 교량을 대상으로, 이에 대해 언급된 온라인 상의 텍스트 데이터를 수집하고 텍스트마이닝 분석을 실시하였다. 이와 같이 한 까닭은 공간에서 일어나는 사건이 어떻게 인식되고 있는지를 살펴봄으로써, 향후 공공장소 자살에 대처하는 공공디자인의 방향성을 제시하고자 함이다. (연구방법) 문헌조사를 통해 전통적 공간의 개념과 공간을 규정하는 속성으로서의 사건 개념을 고찰한다. 이어 사건과 언어의 관계를 살핀다. 공공장소에서의 자살 현황을 소개한다. 실증분석을 위해 포털플랫폼 네이버와 다음의 블로그, 뉴스, 카페, 지식인의 비정형데이터를 수집하고 정제하여 텍스트마이닝 실시한다. 빅데이터 분석프로그램 텍스톰(Textom)과 유씨넷(Ucinet)을 활용하여 키워드 빈도분석, TF-IDF, 네트워크분석, 군집분석을 실시하고 시각화한다. (결과) 빈도 분석 결과 상위 100개의 키워드를 추출하였다. 빈도 분석에서는 교량, 자살, 설치, 안전 등 자살 예방 관련 키워드가 빈출 단어로 나타났다, TF-IDF분석 결과에서는 한강교량, 투신자살, 극단 등의 키워드가 순위 상승하여 사건 자체에 대한 인식이 비중 있게 다루어진 것이 확인되었다. 또한 설치에 관련된 키워드는 빈도 분석과 TF-IDF 분석 모두에서 높은 빈도수를 보여 공간에 무엇인가를 ‘설치’하는 사건이 발생했을 때 주요하게 언급된다는 사실이 확인되었다. 군집분석에서 나타난 8개의 그룹은 물리적, 인적, 시점적 요인으로 분류 가능했으나 인식적 요인은 부족한 것으로 나타났다. (결론) 공공장소에서의 자살 사건은 한가지 원인이나 방법으로 이해하거나 해결할 수 없는 복잡성을 가진다. 본 연구 결과 교량에서의 자살에 관한 우리 사회 일반에서 다루어지는 인식은 자살 예방 구조물의 설치, 상담전화 운영, 구조 활동 등에 집중되어 있으며 인식 변화를 위한 문화적 시도는 미비한 것으로 확인되었다. 따라서 향후 공간의 인식 전환을 위해 경험되어져야 할 사건은 단편적 시설물 설치나 구조활동에서 더욱 확장되어야 하며, 특정한 공공공간이 가진 부정적 이미지나 인식을 개선 시키기 위해 문화적 차원에서 공간디자인이 이루어져야 할 필요성이 있다. (Background & Purpose) This study aimed to investigate the relationship between events in public spaces and perceptions of space through big data analysis. As the subject of empirical research for this purpose, the author focused on suicide cases occurring in a public space, termed a “bridge.” The high suicide rate in Korea is one of the oldest social problems. Suicide-related research so far has been focused on individuals' private spaces or psychological factors, and suicide research targeting public spaces is insufficient. In this study, text data on the Han River, a location where suicides frequently occur, were collected, and text mining analysis was conducted. The reason for doing so is to suggest the direction of public design to cope with suicide in public places in the future by examining how events taking place in space are recognized. (Method) Through literature research, the concepts of traditional space and event as attributes that define space were considered. The relationship between events and language was explored, and the current status of suicide in public places was introduced. For empirical analysis, text mining was conducted by collecting and refining unstructured data from Naver and Daum blogs, news, cafes, and intellectuals. Keyword frequency analysis, TF-IDF, network analysis, and cluster analysis were all performed and visualized using the big data analysis programs Textom and Ucinet. (Results) Keywords related to suicide prevention (e.g., bridge, suicide, installation, safety) appeared frequently. As a result of the TF-IDF analysis, keywords such as Han River Bridge, jumping suicide, and extremes rose in ranking. In other words, the perception of the event itself was treated with great importance. Installation-related keywords showed a high frequency in both the frequency analysis and TF-IDF analysis, confirming that they were mainly mentioned when an incident of installing something in a space occurred. The eight groups shown in the cluster analysis could be classified into physical, human, and temporal factors; however, the cognitive factors were insufficient. (Conclusions) Suicide in public places is complex and cannot be understood or resolved using a single cause or method. Awareness of suicide on bridges was concentrated on the installation of suicide prevention structures, operation of a helpline, and rescue activities, and cultural attempts to change perceptions were found to be insignificant. To change the perception of space in the future, events occurring in space should be further expanded in facility installation or rescue activities, and spatial design should be carried out at a cultural level to improve the negative image or the public space perception.

수평형 지중열교환기의 열전달 성능에 관한 연구

정민호(Chung, Minho),박성룡(Park, Seongryong),나호상(Ra, Hosang),백영진(Baik, Youngjin),윤형기(Yoon, Hyungkee),장기창(Chang, Kichang) 한국신재생에너지학회 2005 한국신재생에너지학회 학술대회논문집 Vol.2005 No.06

Ground source heat pump systems are used for heating, ventilating and air-conditioning systems in commercial buildings, schools, and factories because of low operating and maintenance costs. These systems use the earth as a heat source in heating mode and a heat sink in cooling mode. Ground heat exchangers are classified by a horizontal type and vertical type according to the installation method. A horizontal type means that a heat exchanger is laid in the trench bored in 1.2 to 1.8 m depth. The solar heat and the rainwater are affected by the performance of heat exchanger and causes mutual influence among heat exchangers. In this study, to evaluate the performance of straight type, slinky type, and spiral type of horizontal ground heat exchangers designed on 1 RT scale, test sections are buried on the earth and experimental apparatus is installed. Therefore the performance of these is estimated.

암모니아 수용액의 온라인 농도 측정법의 오차분석

김대환(Daehwan Kim),서동환(Donghwan Seo),정시영(Siyoung Jeong),박성룡(Seongryong Park),김민성(Minsung Kim) 대한설비공학회 2011 대한설비공학회 학술발표대회논문집 Vol.2011 No.7

The information on the solution concentration in absorption heat pump systems is important to evaluate and control the system performance. For ammonia/water heat pump systems, extraction of the solution to measure the concentration is complicated and inconvenient. Moreover, it can be inaccurate because some ammonia is evaporated during the extraction process. In this study, an on-line concentration measurement method for ammonia/water solution was developed. The saturation vapor pressure of a binary mixture solution is a function of temperature, concentration and quality of it. If the quality is zero, the vapor pressure is determined by two independent properties, the temperature and the concentration. Experiments for ammonia aqueous solution have been carried out for a concentration range of 25-45%. The circulation rate and the power of heating/cooling have been varied to analyze the error of the measurement. The result of the on-line method was compared with that of the extraction method which determines the concentration by measuring the density and the temperature of the extracted solution. Both methods showed quite good agreement (within 0.6%) regardless the concentration, circulation rate, and the heating/cooling power. The effect of measurement errors in quality, temperature, and vapor pressure was analyzed.

제주지역 해수열이용 지역냉난방 시스템 보급 모델 분석

장기창(Kichang Chang),김기봉(Kibong Kim),윤형기(Hyungkee Yoon),나호상(Hosang Ra),박성룡(Seongryong Park),김삼열(Samuel Kim) 한국신재생에너지학회 2015 한국신재생에너지학회 학술대회논문집 Vol.2015 No.6