Papers by Keyword: Compressor

Abstract: To execute stall active control technology effectively and make clear of stall inception induced by modal disturbance, this paper carries out the correlative research on modal disturbance and rotating stall on the two-stage low-speed axial compressor. The results indicate that the stall inception of the compressor is modal style and the modal oscillation propagates at 38% rotor speed while the stall cell propagation speed is 42% rotor speed. The phase angles of modal oscillation and rotating stall along the axial direction are different, but their trajectories are both similar to the blade passage shape. The stall mechanisms of modal-type and spike-type inceptions are different. It doesnt appear that leading-edge tip clearance flow spillage blow the blade tip while the modal-type stall formation.

Abstract: Detailed flowfield measurements are made in the end-wall region of a four-stage low-speed large-scare axial compressor test rig. Two ten-hole survey boundary layer probes, one four-hole pneumatic probe, and six dynamic pressure probes each bedded with a high-frequence response Kulite sensor, are designed and manufactured to aid the test. Boundary layer region and mainflow region can be clearly distinguished from the boundary layer measurement results. A few parameters, including boundary layer thickness, displace thickness, momentum loss thickness, energy loss thickness and blockage coefficient are calculated based on the measurements. Results from turbulent boundary layer empirical formula of plate are in good agreement with the mesurements, indicating a way of boundary layer effect estimation. The evolution trajectory of TCV is identified evidently by dynamic pressure measurements. The maximum aerodynamic load point on the blade moves from the trailing to the leading edge as flowrate decreases, which leads to the forward movement of the tip clearance vortex inception point.

Abstract: Recycle hydrogen compressor group is the core equipment of heavy coker gas oil hydrotreater unit of refinery. This compressor adopts tandem structure with intermediate labyrinth seal as its dry gas seal type. The compressor dry gas seal has officially been put into operation for six months, it damaged twice and caused the device to unplanned shutdown, seriously affected the long term operation of the device. During research and analysis on the seal of the unit, a series of problems were found, such as gas anti-channeling, sealing gas with oil etc. After transformation on the sealed gas supply system, the compressor achieved the purpose of long term stable running.

Abstract: The energy saving method in tire factory has got more and more attention. In view of the characteristics that the using air capacity is vast and not steady-going in tire factory, the paper analyses and discusses the enactment of the running parameters and the choice of the running mode about the air compressing system, and sets forth the resolving project to raise the running efficiency and achieve the purpose of energy saving.

Abstract: Though the test of a certain domestic car which cause the car body vibration and cab noise under the idle with turning on and off air conditioning system. The result of the test is analyzed by sound pressure and vibration spectrum, which analysis spectrum-frequency characteristics, affecting factors and noise sources of noise.Finding out the main noise and vibration of interior noise caused by air conditioning and refrigeration system; the car dash panel and body wall is the main transmission route of cab vibration;the people feel uncomfortable when opening the air conditioning under idle, because beat frequency is caused by the compressor and engine. It provides a certain reference for the reduction of noise and vibration of car's air conditioning and refrigeration system.

Abstract: According to the international standard ISO 9614-1:1993 " Determination of sound power levels of noise sources by the sound intensity method - Part1: Measurement at discrete points, the sound intensity test was conducted on the acoustic enclosure for the refrigeration compressor with the PULSE software. The sound insulation performance of the acoustic enclosure was analyzed by comparing the compressors noise with and without the enclosure. The result shows that the noise of the compressor with the acoustic enclosure is less than 60dB (A), and the high-frequency noise can be greatly reduced, which meets the design requirements of noise control. Therefore, it is easy to conclude that the sound insulation of the acoustic enclosure reaches the design standards and the acoustic enclosure design is feasible. The paper provides a valuable reference for the further study on the designing and optimizing of the acoustic enclosure.

Abstract: In this paper, in order to reduce the external radiation of food refrigeration compressors noise, the main noise frequency analysis based on the theoretical calculation and practical experiment is carried out and the acoustic enclosure design is conducted. Conventional sound-absorbing material adopts rock wool and glass wool which have poor environmental protection. In the design process the environmental friendly melamine cotton is chosen as the sound-absorbing material that has not ever been massively adopted. Whats more, with a consideration of ventilation and heat dissipation, acoustic enclosure interior is designed with muffler air duct and the low-speed and low-noise fan. Therefore, both the normal operation of the compressor and the sound insulation of the acoustic enclosure are ensured in this way. Then with the sound level meter the noise A-weighted SPLs of the compressor with and without the enclosure are measured and are compared with each other. The results show that after covering the acoustic enclosure the compressors noise is less than 60 dB, which meets the design requirements of noise control. Therefore, it is easy to conclude that the sound insulation of the acoustic enclosure reaches the design standards and the acoustic enclosure design is feasible.

Abstract: The semi-hermetic reciprocating compressor is the dominant noise source of food refrigeration unit. Excessive noise and vibration have a negative impact on both people's health and work efficiency；moreover, it causes fatigue damage to machinery thus reducing its working life. In this paper, numerical simulation of noise radiation from semi-hermetic reciprocating food refrigeration was carried out by successful combination of Pro/E, Hypermesh, Nastran and Virtual Lab Acoustics software. The simulation results show that the low-frequency noise radiation near the end of the piston-cylinder is directional and stronger than that of the other side, which offers a valuable reference for noise reduction. In addition, the sound pressure dB curve of any field point can be obtained through the numerical simulation, and it clearly shows that sound pressure values away from the piston end are significantly lower than those at the piston side; and noise radiation energy of compressor concentrates at 500Hz and 1000Hz. This paper provides an effective research method for the semi-hermetic reciprocating compressor’s noise reduction

Abstract: To study the similarity scaling of structure for compressor disc, based on the basic rules of similarity scaling, physical speed of five linear scale factors (LSF) is determined, and the ratio of between centrifugal force and LSF is established, then the centrifugal force of single rotor blade and single rim flange with different LSF is obtained. Using the method of finite element numerical simulation, strength of four assessment projects including circumferential stress of disc heart, circumferential stress of cylindrical surface, radial stress of cylindrical surface and circumferential stress of meridian plane is analyzed. The results show that the maximum relative error among four assessment projects is only 2.60%, and stress level of disc corresponding to the different LSF is very close to each other. Then a conclusion can be got that the stress level of disc is little difference with itself geometry size, and the structure of disc can be designed pro rata scaling.

Abstract: In the background of new economical age, the necessity and inevitability of application of knowing-separating–application method and knowledge-to-production and production-to -platform and package-platform-mode (PPM) is introduced. The relative concepts of PPM are set definition. The characteristics and considerations of PPM are studied. For designing of application system complexity and re-usable knowledge module rarely, the application of PPM on research & development of compressor monitoring and diagnosis and maintenance management system-CMDMMS is probed. The PPM is a reliable idea for designing of complex application system.