통합 검색 | Korea Science

지제환;정은수;정시영
- 대한기계학회:학술대회논문집
- /
- 대한기계학회 2001년도 춘계학술대회논문집D
- /
- pp.304-310
- /
- 2001
A numerical model which simulates the heat and mass transfer processes within a counter-current plate type generator for ammonia/water absorption refrigerators was developed. Ammonia/water solution flows downward under gravity and ammonia/water vapor generated by flow boiling flows upward. The flow pattern within the generator was assumed to be a bubbly flow, and the liquid and vapor phase were assumed to be saturated. It was shown that the boiling of ammonia occurred mainly in the upper part of the generator. The effects of the generator length, the wall temperature and the mass flow rate of ammonia/water solution into the generator on the generation of ammonia/water vapor were investigated.
PDF

박수완;하재홍;김기민
- 한국수자원학회:학술대회논문집
- /
- 한국수자원학회 2018년도 학술발표회
- /
- pp.276-276
- /
- 2018
In this paper the potential of the Principle Component Analysis(PCA) technique that can be used to detect leaks in water pipe network blocks was evaluated. For this purpose the PCA was conducted to evaluate the relevance of the calculated outliers of a PCA model utilizing the recorded pipe flows and the recorded pipe leak incidents of a case study water distribution system. The PCA technique was enhanced by applying the computational algorithms developed in this study. The algorithms were designed to extract a partial set of flow data from the original 24 hour flow data so that the variability of the flows in the determined partial data set are minimal. The relevance of the calculated outliers of a PCA model and the recorded pipe leak incidents was analyzed. The results showed that the effectiveness of detecting leaks may improve by applying the developed algorithm. However, the analysis suggested that further development on the algorithm is needed to enhance the applicability of the PCA in detecting leaks in real-world water pipe networks.
PDF