DX-180型玻璃钢扇贝拖网渔船优化改造与试验

针对日本引进的DX-180型玻璃钢扇贝拖网渔船在獐子岛海域捕捞过程中出现的高能耗、低产量等问题,通过对该渔船与獐子岛扇贝捕捞主力船型(辽长渔养15021钢质扇贝拖网渔船)的技术指标差异性分析得出,该渔船配备的捕捞网具与作业模式无法满足中国海域扇贝捕捞需求。因此,该文提出优化捕捞网具与作业模式,并通过在獐子岛虾夷扇贝(Patinopecten yessoensis)底播海域的海上对比试验论证其改造的合理性。试验分2阶段进行,第1阶段通过增大网具扫海面积并对作业参数进行优化与论证,确定在沙砾底、泥沙底和泥底的最佳拖网航速与曳纲长度;第2阶段进行海上生产对比试验,并以单位捕捞油耗、单位捕捞效率和单位捕捞成本为经济评价指标。试验结果表明,优化后的DX-180型扇贝拖网渔船的捕捞量与耗油量均得到有效改善。与预替代的辽长渔养15021钢质扇贝拖网渔船相比,虽单位捕捞油耗与钢质拖网渔船基本持平,但在单位捕捞效率和单位捕捞成本方面均优于钢质拖网渔船,其中单位捕捞效率提高了37.5%,单位捕捞成本降低了26.0%,符合扇贝低碳化产业发展需求,对中国推广玻璃钢扇贝拖网渔船从技术与经济性方面提供参考。

Optimization remould and experiment on DX-180 fiber reinforced plastic trawler for scallop

Abstract: In order to demonstrate whether the operation mode and equipment of the DX-180 FRP scallop trawler imported from Japan are suitable for the scallop fishing demand in China, preliminary tests and comparison were conducted in Zhang Zidao island. The results showed that DX-180 scallop trawler''s oil-fish rate is significantly higher than that in Europe and in Zhang Zidao of China. Therefore, it is necessary to optimize the operation mode and equipment of the DX-180 FRP scallop trawler to meet the sustainable development of scallop industry needs.There were two phases for optimizing operation mode and catching equipment of the DX-180 FRP scallop trawler. The first phase was carried out to determine the optimum technological parameters of operation mode in three different bottom sediments (coarse sand, smooth sand and smooth mud), based on increasing fishing dredge''s sweeping area, and analyzing the critical influencing factors (trawl speed and steel warp length) on fuel consumption per tonnage scallops by orthogonal experiment. The second phase was to conduct comparative test of sea production, based on the first research results and actual production situation. The tests lasted for 12 d and 8 h per day in three bottom sediments, with each bottom sediment caught 4 d. By the end of each test day, calculate the amount of fishing, number of fishing and fuel consumption.Results of the first phase experiment showed that the optimum trawl speed and steel warp length are 2.1 m/s and 235 m, 2.1 m/s and 230 m, 2.3 m/s and 230 m respectively for coarse sand, smooth sand and smooth mud. The order of influence factor on unit fuel consumption is trawl speed> steel warp length. The results of the compared tests at the second stage showed that the amount of fishing, number of fishing and fuel consumption of the optimized DX-180 scallop trawler were all improved. Compared with original, the average daily catching of the optimized DX-180 scallop trawler increased by 226%, 238% and 243%, respectively, and the fuel consumption decreased 19.2%, 18.0% and 12.4% in the three different bottom sediments respectively. Compared with Liao Chang Yu Yang 15021 steel scallop trawl, the number of fishing with the optimized DX-180 scallop trawler increased 4 times per day in three different bottom sediments, and the average daily catching increased about 64.8%, 63.6% and 86.0% respectively. At the same time fuel consumption increased by 63.2%, 63.5% and 76.8% respectively. The economy analysis showed that the three economic evaluation indexes (unit fuel consumption, unit fishing efficiency and unit fishing cost) of the optimized DX-180 scallop trawler were better than those of the main ship which will be renewed and reconstructed (Liao Chang Yu Yang 15021 scallop trawler). Compared with original one, the unit fuel consumption of optimized trawler under the three kinds of sediments decreased by 290%, 299% and 285%, respectively. Compared with the existing steel scallop trawl (15021 scallop trawler), the fuel consumption per unit of coarse sand and smooth sand reduced by 1.31% and 0.22%, respectively, but there was no significant difference (P>0.05), and the fuel consumption per unit of catch in the smooth mud was reduced by 5.21%, and there was significant difference (P<0.05). From the perspective of unit fishing efficiency, it is found that unit fishing efficiency of the 15021 scallop trawler is 0.16 km2/kW, while DX-180 scallop trawler''s unit fishing efficiency is 0.22 km2/kW, which increased by 37.5%. At the same time, the unit cost of DX-180 FRP scallop trawler is 26.0% lower than that of 15021 scallop trawler. Therefore optimized DX-180 scallop trawl can replace the existing steel scallop trawlers, and meet development needs of green enterprises.