Small rotor clearances are today a vital prerequisite for an efficient screw compressor. The clearances are responsible for compressor leakages, small clearance will minimise them and thereby increase both, the volumetric and adiabatic efficiency. A continuous improvement in the rotor manufacturing equipment has been achieved during the recent years and tight production tolerances may now be ap...

The air compressor provides not only the required pressure air for the cooling equipment and refrigeration plant, but also the raw material required for the air separation plant. Utilizing the air compressor is extremely extensive in many significant departments such as the metallurgy, oil and chemical industry. The air compressor production process is a time-varying, delay and nonlinear comple...

Increasing demands for more efficient screw compressors require that compressor designs are tailored upon their duty, capacity and manufacturing capability. A suitable procedure for optimisation of the screw compressor shape, size, dimension and operating parameters is described here, which results in the most appropriate design for a given compressor application and fluid. It is based on a rac...

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...

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...

Iran’s vast common natural gas resources and the necessity to extract and export it as Liquefied Natural Gas (LNG) to distances more than 3000Km opens a lucrative field for researchers to optimize LNG cycles. In this article heat integration in cryogenic cycles by determining interacycle partition temperature and optimizing refrigeration features like Subcooler, Presaturator, aftercooler, reboi...

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-...