Dissertation > Excellent graduate degree dissertation topics show

Noise and Vibration’s Optimization of Rotary Compressor

Author: DingHongLiang
Tutor: MengGuang；ZhouYi
School: Shanghai Jiaotong University
Course: Mechanical Engineering
Keywords: Rolling piston compressor Noise and Vibration Natural frequency FEM
CLC: TB652
Type: Master's thesis
Year: 2008
Downloads: 112
Quote: 0
Read: Download Dissertation

Abstract

This paper describes the optimization process of the air-conditioning compressor noise and vibration. Noise and vibration is the focus of attention problems, excessive noise can affect the quality of sleep, excessive vibration will make the pipe easily vibration bifida. The 3HP following home air conditioning compressor for the rolling piston compressor. In this paper, a single-rotor the optimized rolling piston inverter compressor noise vibration. The compressor applies to 22-26 models air conditioning, miniaturization structure and frequency REPM. So with high efficiency and low cost advantages. But smaller structure so that the inertial mass is also smaller, relatively poor for vibration suppression; therefore its noise and vibration optimization requires a new approach. The baseband noise and vibration measurements in accordance with the conditions of the four air-conditioned Japanese APF (annual performance factor) test and found the problem: cold and warm room freeze conditions a 5 octave Peak (300-400Hz) conservatory freeze conditions of 1200Hz peak cut generally higher vibration acceleration reason Noise focus on 1000Hz frequency because of the low frequency noise is difficult to eliminate sound-proofing material. Analysis found, the motor the monomer noise test, variable the pressure speed test, test of positioning components inherent frequency calculation and measurement, noise vibration testing found abnormal noise and vibration for the following reasons: warm and cold room freeze conditions baseband octave source of noise in the electromagnetic noise of the motor and close to the natural frequency with the pump, thereby causing more noise peak; conservatory fixed grid the 1200Hz Noise is caused because the motor, and the 2,3-order mode of the accumulator state close , so as to stimulate greater noise. The tangential vibration acceleration higher peak, considered to be the cause of instability of the state of the rotary compression. Therefore, according to the characteristics of the frequency single rotor compressor to re-optimize the design of the rotor - crankshaft rotation system. First, by improving motor rotor - the crankshaft rotation frequency of the system thereby reducing the heating and room given the grid conditions baseband 5 octave noise, by raising the natural frequency of the accumulator thereby reducing the conservatory fixed grid conditions 1200Hz Noise. Through the establishment of the rotor - crankshaft system, a finite element model of the bearing system and discrete design, the unit shape function (infinite dimensional problem into a finite dimensional), take advantage of the knowledge of rotor dynamics, find the element mass matrix, gyroscopic matrix is ??obtained and stiffness matrix, using the principle of virtual work of the external forces into the equivalent nodal force vector, the final kinetic expression. Obtained the film element stiffness matrix and the film unit to create a finite element model of the bearing oil film fluid Reynolds equation variational form of variational inequality is equivalent to a very small value problem-shaped function unit divided by rectangular elements, force vector, the overall equation. Finally, the rotor-bearing system coupled design, rotary compressor rotor - bearing system dynamic coupling problem is a strongly nonlinear fluid-structure interaction problems. This article involves solved in three domains: the rotor, the bearing body, bearing oil film. Because the the crankshaft rotor and the bearing body similar to the form of the equation, so the overall numerical method coupling; alternate methods of solving coupled film equation. Simultaneous rotor model, bearing model equations can be obtained following overall equation, then alternately solving and bearing oil film model equations. By the above method and programmed, you can calculate the orbit, crankshaft deflection and bearing crankshaft deformation, so that you can optimize the state of rotation, so as to achieve the effect of reducing the noise and vibration. Take such improvements, the aircraft noise and vibration acceleration to reduce a certain level, making the product performance to meet user demand.

Related Dissertations

CLC: > Industrial Technology > General industrial technology > Refrigeration Engineering > Refrigeration machinery and equipment > Compressor
© 2012 www.DissertationTopic.Net Mobile