| With the increasing number and power of fishing vessels in China,the annual total fuel consumption of our fishing boats are already in the forefront of the world.According to the data of the fishery statistical yearbook,the annual total fuel consumption of our fishing boats is about 7.9 million tons,of which trawlers are the mainstay of fuel consumption of fishing boats.Since the main energy consumption of fishing vessels lies in the main engine,the state has introduced a series of policies to limit the number and power of fishing vessels.The purpose is also to prevent overfishing and avoid excessive energy consumption,but the effect is not obvious,which brings new challenges to the industry.This subject is based on the diesel engine type spectrum review and identification project for fishing vessels.For energy saving,emission reduction,the prevention of large scale and small scale,we studies the fishing boat,the main engine and the propeller.It provides the best matching scheme for the 24 m trawler.The actual fishing boat fuel consumption is compared and the ship simulation data is analyzed to verify the rationality of the matching scheme.This paper firstly analyzes the theoretical analysis of the matching of ship propellers and the way to use the software and the knowledge of the matching theory of the propellers to match the ship's oars.Through the analysis of the spectrum data of the diesel engine of the fishing boat,the basic data of the national diesel engine for fishing boats are mastered and can also be used to prepare for the selection of the following main engines.And then we can match the research of the 24-meter trawler in Weihai City through the NAPA software and obtain the fuel consumption of the ship at the design speed,and after that we will compare and analyze the experimental result with the simulation data.The main research contents of this paper are as follows:(1)Mainly explain the background and significance of the research,the status quo of research at home and abroad,etc.According to the rapid performance prediction and analysis of ships using NavCad software abroad,we will adopt advanced digital calculation methods(such as CFD,Computational Fluid Dynamics,Computational Fluid Dynamics).The fluid dynamics estimation is gradually increasing,which provides a software reference for the simulation analysis later in this paper.(2)Analysis of ship propeller characteristics,and analysis of the fishing boat's resistance characteristics,main engine characteristics and propeller propulsion characteristics.Through the analysis of fishing boat resistance,the effective power of the fishing boat is obtained,and the corresponding propeller and main engine are matched according to the effective power curve.(3)The analysis of matching characteristics of machine propellers mainly expounding the balance relationship of fishing boat propellers,the interaction relationship between ship propellers and matching methods,and constructs corresponding models to analyze the performance of fishing boat propeller matching curves.(4)We select and calculate the 24 m trawler model,and through calculating the hydrostatic force by NAPA software,we also obtain the effective power of the trawler,matching the corresponding B-type propeller: D=1.7m,P/ D = 0.623,the number of leaves of the propeller is n = 4,and the disk factor is 0.58.For the common working conditions of the ship and the required speed,the diesel engine of WP13C500-18 model of Weichai Power Co.,Ltd.WP13 series was selected as the main engine in the type data,and the fuel characteristics test was carried out on the model,and the result is consistent with the curve characteristics of WP13C500 and the host fuel consumption rate of the fishing boat at the design speed under the matching scheme is analyzed.(5)Based on the existing 24-meter trawler hull line drawing,the 3D model was built with the MAXSURF software developed by Planning Design Systems of Australia,and then the commercial CFD software STARCCM+(Ver 12.02)was used to analyze the fuel consumption of the ship at various speeds.characteristic.The specific simulation process: Calculate the total ship's resistance under the three-dimensional model scale of the fishing vessel by CFD method,and then obtain the total ship's total resistance and effective power by means of the two-factor conversion method of the model resistance to the real resistance conversion;the ship propulsion factor is calculated by the empirical formula.The B-series propeller and Ka series propeller open water experimental data were obtained by CFD,and then the fuel consumption characteristics of the two series of propellers were calculated by interpolation method by means of the existing main engine fuel consumption test data.Through the analysis of the above content,the following conclusions are obtained:(1)To compare these methods,we calculate the effective power of the hull by NAPA software,NAVCAD software and Starccm+ software,and then draw the effective power curve.we finally find that the data of the effective power calculated by NAPA software is closer to the effective power of the hull.(2)We study the resistance calculation of 24 m trawler in Weihai City through NAPA and design a set of optimal matching scheme: The main parameters of selecting B-type propeller are as follows: D=1.7m,P/D=0.623,the blade of the propeller The number is n=4 and the disk factor is 0.58.Host selection: Weichai WP13C500-18 diesel engine,choosing the gearbox with a reduction ratio of 4.3.When the speed of the fishing boat is 10 kn,the main engine oil consumption rate is 195.6g/kWh,compared with the actual fuel consumption of 230g/kWh.To verify the rationality and economy of the matching scheme.(3)By comparing and analyzing the fuel consumption of the 24-meter trawler B-type paddle and the catheter paddle,it is concluded that the B-type paddle is more fuel-efficient and economical under the same situation of the host.(4)Simulation analysis of the fuel characteristics of the trawler,it is concluded that the rated power of the host matched by the 24 m trawler does not exceed 365 KW,which can provide a theoretical basis for the verification of the large-scale small-scale phenomenon.(5)The research on the matching of fishing boat propellers has important practical significance for expediting the development of “efficiency,environmental protection,energy saving and economy” of fishery. |
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