Patent ID: 8152475
Filing Date: 2012-04-10
Classification: F04B

Abstract:
1. A method for controlling the operation of a compressor, in which the compressor is switched off by a control unit to avoid thermal damage if a compressor temperature value (Ts(Tc)) calculated by said unit exceeds an upper threshold value (T max ), or remains switched on or is switched on if there is a compression requirement and if a lower threshold value (T min ) is not reached, comprising the steps of: storing a mathematical-physical model in memory of the control unit wherein the mathematical-physical model characterizes cooling and heating properties of the compressor; and calculating a temperature value (Ts(Tc)) of the compressor indirectly and cyclically by means of the mathematical-physical model by determining physical-technical influencing variables (U), which influence the estimated temperature (Ts(Tc)) in a changing manner, determining, with the aid of the influencing variables (U), at least one relative temperature (Tc adding or subtracting, for this purpose, the currently applicable influencing variables (U) from the cyclically prior value of the relative temperature (Tc determining a currently applicable estimated temperature (Ts(Tc)), taking into account the heating and cooling behavior of the compressor, from this currently applicable relative temperature (Tc using this cyclically calculated temperature (Ts(Tc)) for carrying out a limit value comparison with a lower temperature threshold value (T wherein the influencing variables (U) are entered in a heating function (B(U)), which describes the heating behavior of a specific compressor.