This paper demonstrates a typical process to investigate the vibro-acoustic behavior of R410A rotary compressors. The compressor shell is usually the main noise radiator in a rotary compressor. However, the accumulator shell can be a significant noise source as well, although its size is relatively small. Sound performance of a rotary compressor is affected not only by the dynamic characteristi...

A dynamic model of a centrifugal compressor capable of system simulation in the virtual test bed (VTB) computational environment is presented. The model is based on first principles, i.e. the dynamic performance including the losses is determined from the compressor geometry and not from the experimentally determined characteristic performance curves. In this study, the compressor losses, such ...

We determine the asymptotically optimal compressor function for a multidimen-sional compander when the source is memoryless. Under certain technical assumptions on the compressor function, it is shown that the best k-dimensional compressor function consists of the best scalar compressor functions for each component of the source vector. The mean-squared error of optimal multidimensional compand...

One of the most important methods of transporting natural gas in Iran and other parts of the world is the utilization of a network of pipelines. Compression station and turbo compressor units play an important role in gas supply through pipelines. One of the primary concerns in these units is the reduction of fuel consumption. By cooling of exhaust gas from the source station, the pressure drop...

This paper presents how we improved the efficiency in rotary compressor. At first, we made effort to estimate the power losses in the compressor, to analyze the operating conditions of the bearing and to calculate the performance of the compressor. Next, the temperature in housing and pressure in cylinder were measured in real compressors in order to obtain the data on the internal conditions o...

The present paper is a numerical and experimental comparative study of hermetic and semi-hermetic reciprocating compressors working with carbon dioxide as fluid refrigerant against the conventional R134a hermetic compressors. When cooling conditions for one-stage compressor type (i.e., evaporation temperatures between 7.2oC and –10oC) have been considered, the numerical and experimental results...

Compressors are a primary cause for numerous HV AC noise and vibration problems. Typically, vibration energy is transmitted from the compressor to the chassis through piping and isolation mounts. The design of these attachments is thus of paramount importance in determining the dynamic performance of a HV AC unit. Below certain frequencies, compressor vibration can be well described as a rigid-...

This paper proposes a robust design scheme for the control of surge phenomenon appearing in a centrifugal compressor. It is known the surge instability in compressor might lead to reduce the operating efficiency and even damage the machinery while both of unstable compressor characteristics and compressor load torque are hard to exactly measure in the practical application. Based on the assumpt...

The presence of liquid refrigerant in the compressor cylinder during operation, or liquid slugging, is one of the most common causes of failure in reciprocating compressors. We propose to detect this fault by analyzing the electrical current flowing into the compressor and identifying the change in the load on the motor caused by the presence of liquid in the compressor cylinder. Two different ...

Designing multipliers that are of high-speed, low power, and regular in layout are of substantial research interest. Speed of the multiplier can be increased by reducing the generated partial products. Many attempts have been made to reduce the number of partial products generated in a multiplication process one of them is Wallace tree multiplier. Wallace Tree CSA structures have been used to s...