Study On The Optimal Design Of Scroll Profiles Based On Multiobjective Genetic Algorithms

As the main work and energy consuming device of small and medium sized air-conditioning units, scroll compressors have much inapproachable advantages over any other kinds of compressors, such as low level of vibration and noise, light weight, high efficiency, high reliability, low energy consuming. It seems very important to people on a condition that the energy is lacking day by day, and people require the higher life quality more and more. The efficiency is constricted by many factors, the most essential one of which is the shape of the scroll profile. For that the profile of the scroll affects the leakage and the efficiency. Many researchers usually simplify it as a single optimization problem using traditional methods for lack of the concise and effective mode. After deep researching on the form of scroll compressors, a study on multiobjective optimization using nondominated sorting genetic algorithm is developed. The research work is given as follows. Aiming at the difficulty of traditional form and the lack of the concise and effective mode, the geometry characteristic, the theory of conjugacy and the form of scrolls are analyzed. A general describing mode of scrolls based on Whewell equation is presented on the design of profiles.The paper compares traditional algorithms with genetic algorithms on multiobjective optimization design. The theory of multioptimization is systematized. The advantages of multiobjective optimization algorithm are developed. Then, a multiobjective genetic algorithm —nondominated sorting genetic algorithm, which can obtain the Pareto optimal sets quickly, is discussed.A multiobjective profile optimization of scrolls is first presented, and a calculating model of multiobjective profile optimization is established, which fits the multiobjective optimization of the scroll integrated form. After that, nondominated sorting genetic algorithm is applied in the multiobjective scroll profile optimization successfully. At the same time, the optimal design project with multiperformance is obtained.The multiobjective optimization procedure of the scroll integrated form based on Whewell equation is integrated by means of Visual C++. The result shows that the optimal scroll with many advantages can meet the demand of multiperformance in practice.Using software I-deas, the paper founds a three-dimensional simulation model of a sample. The simulation procedure is given. The result of the simulation verifies the validity of the method and the technique line, which is applied in research. And some geometric parameters of scrolls are developed.