Abstract:
The fisheries sector in Sri Lanka has been expanding during past decade with growing local demand and export of fish. In order to cope with the demand, the size of fishing boat used for multi-day, deep-sea fishing has now increased up to 60 ft. There are more than 1700 such boats working around Sri Lanka and building of such boats progress continuously. Most of these designs are based on the extension of small multi-day boats but no attention is paid to the technical feasibility of increasing boat capacity by scaling up the dimension to make the boat bigger. Although there are important factors and views to be discussed with regard to altering a design, such factors are beyond the scope of this research.
In view of the operation of these boats at least 2-3 weeks are needed to complete one voyage of fishing. However, the concept of fish preservation still remains conventional by using the ice cold fish hold that was used for small multi day boats. This method offish preservation would have been economical for small boats that carry about 2-5 tonne of fish but as the boat size increases, preservation by ice may have following disadvantages.
a. Full capacity offish hold cannot be used for storing fish
b. High fuel consumption at departure condition to carry considerable amount of
ice. c. Impossible to maintain an acceptable temperature inside the fish-hold.
d. Duration of fishing and amount of the catch is limited depending on available
ice.
e. Operating cost of the vessel increases and the quality of fish becomes poor due
to the all above factors.
Although there are refrigeration systems available in the foreign market, the cost and compatibility of such systems to local requirement are questionable. A system that satisfies required refrigeration capacity for a 40 ft boat costs about 1.5 million rupees.
Intention of this research is to investigate the economical feasibility of designing and construction of suitable refrigeration system to overcome the above problem.
