碩士 / 國立高雄海洋科技大學 / 輪機工程研究所 / 99 / The purse seiner is one of the fishing vessels with lots of capital and technology in fishery industries. In west Pacific Ocean, there are 205 American Purse Seiner vessels, of which 88 vessels belong to Taiwan ship-owners (34 vessels are registered in Taiwan others are convenience flag ships). It almost occupies approximately 43 percents. The annual catching of these 34 Taiwan vessels is about two hundred thousand tons, and this is the largest amount in Taiwan deep-sea fishery. The most influential effect of the fish price depends on its fresh condition which can be well tackled by refrigerating the captured fish in best freezing condition. Thus, the design of the freezing system is of paramount importance.
A 1100-ton Purse Seiner vessel of the latest design was to achieve cooling approximately 220 tons of fresh cargo (skip jack) from 2°C to -17°C within 24 hours with the aid of brine. After that, the skip jacks are moved to the dry hold and are maintained at about -40°C. The designed cargo capacity were about 1485 cubic meters, and the Purse Seiner vessel can accommodate 935.55tons (ρ=0.63 T/m3 ) at full catching and transits cargo to another vessel one time per month.
This article investigates the latest condenser in a refrigerating system of Purse Seiner vessels. Nowadays, the condenser uses pure titanium tubes to replace the traditional steel tubes. Though the titanium condenser has the heat transfer area much smaller than that of the steel-tube condenser, the two condensers possess almost equivalent heat transfer performance. In addition, the former has larger margin in condensing because of its greater overall heat transfer coefficient. Moreover, it is reported that the service life of titanium tube is about 20-30 years.
Key words : purse seiner, brine, pre-cooling, full catching, transit cargo
| Identifer | oai:union.ndltd.org:TW/099NKIM8484006 |
| Date | January 2011 |
| Creators | Lee,Cheng-Chung, 李正忠 |
| Contributors | Yeh,Rong-Hua, 葉榮華 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 91 |
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