Development of Energy Efficiency Design Map based on acoustic resonance frequency of suction muffler in compressor
Nederland | Applied Energy
2015-01-23 | 바로가기
Cited by 10
■ View full text
Received 23 January 2015, Revised 26 March 2015, Accepted 12 April 2015, Available online 22 April 2015.
Seungjae Oha, Semyung Wanga, Sungman Chob
a School of Mechatronics, Gwangju Institute of Science and Technology (GIST)
b Home Appliance Laboratory, LG Electronics Inc.
The acoustic source in fluid machinery is described as nonlinear. However, acoustic wave propagation in the muffler is represented by a linear system. Therefore, the acoustic source is modeled in the time domain, and the acoustic propagation is expressed in the frequency domain. The method of analyzing the acoustic in different domains is known as hybrid coupling. In this paper, a developed non-iterative hybrid coupling method was suggested, where the parameter identification using the rational fractional polynomial method is performed with the measured input impedance of the muffler described in the frequency domain. In this case, the relationship of the polynomial order of the denominator and numerator was determined from the analogy of a mechanical system. The approximated input impedance model is transformed to the state space model, which is described in the time domain. Finally, this model is coupled to a nonlinear acoustic source to analyze in the time domain. The proposed method can be used in more diverse condition than the other method. Simultaneously, a transient response can be obtained. The proposed method was experimentally verified using the suction part of a linear compressor, which is representative of fluid machinery.
Energy has recently been an active area of research due to the energy shortage and factors influencing consumers’ purchasing decisions. In this study, a method for improving the overall energy efficiency of a compressor by using acoustic pressure was developed for the first time and this effect was named as ASEE.
Herein, an analysis method considering the acoustic pressure in the suction muffler of a compressor was first discussed. In particular, a hybrid coupling method between the nonlinear acoustic source and the linear acoustic propagation system was introduced. Then, four basic models designed for the compressor analysis were described.
Based on the hybrid coupling analysis method, the EEDM was proposed as a guide for suction muffler design. When an EEDM is generated, normalization of the magnitude of the input impedance and multiplication by a scale factor are required. The variations of EEDM was observed according to the scale factor. Through this, the magnitude of input impedance was determined.
A sensitivity analysis with respect to the acoustic pressure was performed, and the EEDM was physically explained using the results of this sensitivity analysis.
Finally, in this study, a framework for improving the ASEE was suggested.
Many studies have attempted to increase the volumetric efficiency of fluid machinery instead of increasing their energy efficiency. However, as shown in this study, the highest volumetric efficiency does not necessarily imply the highest EER. In our study, the highest volumetric efficiency of a suction muffler model was evaluated at the lowest EER. Therefore, direction of design for acoustic supercharging is different from the direction of design for ASEE. To improve the overall energy performance of a compressor, designing based on ASEE is a suitable approach.
The results of this study will be useful for those who study engines in automobile and compressor.
* 관련 자료