Papers by Keyword: Reciprocating Compressor

Abstract: In this paper, by designing a new type of mechanism, the time-varying cylinder load ofthe reciprocating compressor is simulated. The time-varying cylinder pressure load includes fourprocesses of expansion, suction, compression and exhaust, where the pressure of the expansionprocess is gradually reduced until it is equal to the suction pressure, and the pressures of the suctionand exhaust processes are almost constant. The pressure of the compression process is graduallyincreased until it is equal to the exhaust pressure value. Through the motion simulation of themechanism, four processes of time-varying cylinder pressure load can be realized. This newmechanism will provide new ideas for the time-varying load involved in the simulation of thereciprocating compressor fault test bench.

Abstract: In condition monitoring (CM) signal analysis the inherent problem of key characteristics being masked by noise can be addressed by analysis of the signal envelope. Envelope analysis of vibration signals is effective in extracting useful information for diagnosing different faults. However, the number of envelope features is generally too large to be effectively incorporated in system models. In this paper a novel method of extracting the pertinent information from such signals based on multivariate statistical techniques is developed whichsubstantialy reduces the number of input parameters required for data classification models. This was achieved by clustering possible model variables into a number of homogeneous groups to assertain levels of interdependency. Representatives from each of the groups were selected for their power to discriminate between the categorical classes. The techniques established were applied to a reciprocating compressorrig wherein the target was identifying machine states with respect to operational health through comparison of signal outputs for healthy and faulty systems. The technique allowed near perfect fault classification.In addition methods for identifying seperable classes are investigated through profiling techniques, illustrated using Andrew’s Fourier curves.

Abstract: High frequency vibration signal, cylinder-inside pressure and ultrasonic wave are monitored under working condition of a reciprocating compressor. High frequency vibration signal and ultrasonic wave are processed using high frequency band-pass filtering, and then enveloped. The pressure signal is filtered with a low-pass digital filter. The fault causes of the machine can be determined by the enveloped waveform of vibration signal and ultrasonic wave, as well as the pressure curve comprehensively. We can confirm the truth that this fault diagnosis method is accurate and reliable for reciprocating compressors through a number of the results of fault diagnosis.

Abstract: Research was made in order to design a good reciprocating oilless air compressor. Grease lubrication bearings are used in connecting rod larger heads, smaller heads and main shaft necks, its structures are designed, so the oilless lubrications are achieved over there. Self-lubricating materials are used to make piston pings and guiding pings, the lap-joint structure is used in piston pings, so the problems of oilless lubrication and seal between piston component and cylinders can be solved. The structure of unloading slots for guiding pings, smaller radius-length ratios and lower pressure ratios can make piston pings and guiding pings run long time. Series products of oilless air compressors which are made as above have gone into mass production.

Abstract: This paper presents a feature extraction method based on LMD and MSE for reciprocating compressor according to the strong nonstationarity, nonlinearity and features coupling characteristics of vibration signal. The vibration signal was decomposed into a set of PFs, and then multiscale entropy of the first several PFs were calculated as feature vectors with different scale factors. Based on the maximum of average Euclidean distances, the feature vectors which have the best divisibility were selected. The feature vectors of reciprocating compressor at different bearing clearance states were extracted using this method, and superiority of this method is verified by comparing with the results of sample entropy.

Abstract: In order to determine the vibration characteristics of the reciprocating compressor on the offshore platform, the vibration signal from the reciprocating compressor on the offshore platform was investigated by applying the harmonic wavelet packet transform. The energy variation of vibration signal under the different frequencies was discussed. It was shown that the vibration energy of the reciprocating compressor in the horizontal and vertical directions is mainly concentrated in the low frequency of 25Hz and 50Hz, and the vibration energy of other frequency is small and smooth. In the axial direction, the vibration energy of the reciprocating compressor extends to the medium-high frequency, and the large energy appears in the 225 Hz. Therefore, the harmonic wavelet packet transform can be used to research the vibration characteristics of the reciprocating compressor on the offshore platform.

Abstract: Crankshaft is one of the important parts of reciprocating compressor. It takes a large reciprocating compressor crankshaft as the research object. First it establishes the three-dimensional solid model of the crankshaft by the software Pro/E. Then it contacts the Pro/E and ANSYS Workbench by the interface to establish the finite element model of the crankshaft. After taking the modal analysis and calculations of the crankshaft in the ANSYS Workbench module, it obtains the foundation for the design of the crankshaft structure.

Abstract: This paper describes a design optimization to achieve optimal performance of a two novel single-phase short-stroke tubular linear permanent magnet motors (TLPMMs) with rectangular and trapezoidal permanent magnets (PMs) structures. The motors equipped with a quasi-Halbach magnetized moving-magnet armature and slotted stator with a single-slot carrying a single coil. The motors have been developed for reciprocating compressor applications such as household refrigerators. It is observed that the TLPMM efficiency can be optimized with respect to the leading design parameters (dimensional ratios). Furthermore, the influence of mover back iron is investigated and the loss of the motor is computed. Finite element analysis (FEA) is employed for the optimization, and the optimal values of the ratio of the axial length of the radially magnetized magnets to the pole pitch as well as the ratio of the PMs outer radius-to-stator outer radius (split ratio), are identified.

Abstract: For shorten the product design cycle and saved the cost, the 2.5L reciprocating compressor crankshaft is parametric designed by Pro/E. stress analysis about crankshaft during a revolution was done to check each dangerous cross-section based on dynamics, materials mechanics. The result shows that the feature parametric designs obviously shorten the design cycle and saved the design cost of different specifications crankshafts for reciprocating compressor.

Abstract: Mechanical model of crankshaft and connecting rod mechanism of reciprocating compressor was built. Then the order of stress was obtained every ten degrees while crankshaft turning. The larger stress of crankshaft initial turnings was utilized to calculate the whole model and the unreliable region and destructive working condition then was determined. The situation was simulated with ANALYS and the static characteristics, i.e. stress and strain, of the crankshaft was also obtained. The simulated results testify the analysis and the results of the paper have great value for reference when designing crankshafts.