In order to evaluate the energetic quality of a compressor (as with all energy machines) an efficiency is calculated. With piston compressors also a volumetric efficiency is being used, which is defined as the useable part of the piston displacement for gas delivery…
- Introduction to Thermodynamics
This section is meant for those readers, who have no basic knowledge of thermodynamics so far, but who would like to be able to follow the thermodynamic considerations in the following chapters. For further information on thermodynamics we recommend for example [2].
- Compressors
Compressors are machines, which increase the pressure of a gas through input of mechanical work… - Reciprocating compressors
Reciprocating compressors work according to the positive displacement principle… - Compressor station
Compressor stations consist of a compressor and different other components, which are… - Pumping duties
Compressors are chosen or developed according to their defined pumping duty…
- History and development
Pressure increase of air by applying mechanical work had already been done in early times. In the middle ages hand operated bellows were used in metal foundries… - Process and natural gas compressor
Process compressors used in the process industry (for example in the liquification, rectification and with chemical reaction of technical gases) have to fulfil demanding requirements in relation to performance and reliability… - Air and refrigeration compressors
Whilst stationary compressors for air are carried out in increasing numbers as screw compressors, air compressors for road vehicles are still being developed in the plunger type design…
- Drive mechanism
The driving gear of the compressor converts the rotating motion of the crank into the oscillating motion of the piston and also transmits work… - Cylinders
Cylinders comprise the working chambers, the compressor valves and the cylinder cooling. The design of the cylinder is adapted to the specific pumping duty…
- Interstage systems
For the interstage and final cooling in piston, compressors have to fulfill specific requirements… - Compressor valves
The gas flow in and out of the cylinder is controlled by self actuated, that is gas pressure controlled in- and outlet valves (suction and discharge valves)… - Piston rings and packings
The sealing of the piston against the non moving cylinder wall is done usually by piston rings touching the cylinder wall…
- Processes in the working chamber
An approximate calculation of the working cycle for a specific cylinder of your choice can be carried out with the program… - Flow through the stage
The quasi stationary changes in the conditions of state of the gas when flowing through a compressor stage can be represented in a T,s- diagram… - Efficiency of compressors
- Characteristic diagrams
Characteristic diagrams show volume flow and the required work input for variable working conditions… - Control operation and regulation
In order to achieve a certain required operating condition a control operation is carried out either on the installation, the compressor drive or on the compressor… - Monitoring and diagnosis
Important components of piston compressors are subject to wear which cannot be avoided and which could lead to a shutdown of the compressor with subsequent loss of production entailing high costs as a consequence… - Trends
Development is driven by the continuing growing possibilities of theoretical simulations of those physical processes in compressor intallations, which reduce their life expectancy and efficiency…
- Bibliography
[0] Küttner, K. H.: Kolbenmaschinen. B.G. Teubner, Stuttgart 2009
[1] Kleinert, H.-J.; Wächter, K.: Grundlagen der Kolbenmaschinen. Abschnitt 1 in: Taschenbuch Maschinenbau, Band 5, Kolbenmaschinen, Strömungsmaschinen, Berlin 1989, Verlag Technik.