Method for operating a rotational-speed-variable refrigerant compressor

Abstract

The invention relates to a method for operating a rotational-speed-variable refrigerant compressor (2) for cooling a cooling volume (4) of a refrigeration system (1), which refrigeration system does not have its own control unit, wherein the refrigeration system (1) comprises at least one thermostat (3) for directly or indirectly monitoring a temperature state of the cooling volume (4) and wherein the rotational-speed behavior of the refrigerant compressor (2) during a cooling cycle is controlled by means of a specification rotational-speed control stored in an electronic control device (6) of the refrigerant compressor (2). According to the invention, in order to enable adjustment of the rotational-speed behavior in reaction to a preceding special operating state and to enable energy-optimized cooling of the cooling volume (4) that is as fast as possible, at least one comparison parameter is stored in the electronic control device (6) of the refrigerant compressor (2) and exceedance or undershooting of the comparison parameter by a current measured parameter value is monitored, a special cooling cycle different from the specification rotational-speed control is triggered if the current measured parameter value exceeds or undershoots the comparison parameter, possibly, a current cooling cycle controlled by means of the specification rotational-speed control is interrupted by the special cooling cycle.

What is claimed is: 
     
         1 . A method for operation of a rotary speed-variable refrigerant compressor for cooling a cooled volume of a refrigeration system, wherein it comprises a thermostat for direct or indirect monitoring of a temperature state of the cooled volume and where the refrigerant compressor is operated cyclically, and a cooling cycle (C K ) of the refrigerant compressor begins when the refrigerant compressor is set into an ON state by a switching signal triggered by a thermostat, and the cooling cycle (C K ) ends when the refrigerant compressor is set to an OFF state by an additional signal triggered by the thermostat,
 where an operating cycle (C) comprises, besides the cooling cycle (C K ), a rest cycle (C R ) following the cooling cycle (C K ),   and where the rotary speed behavior of the refrigerator compressor is controlled during a cooling cycle (C K ) by means of a preset rotary speed control stored in an electronic control device of the refrigerant compressor, wherein
 at least one comparison parameter (P V ) is stored in the electronic control device of the refrigerant compressor and an exceeding or falling short of the comparison parameter (P V ) by a currently measured parameter value (P a ) is monitored, 
 a special cooling cycle (C D ) that is different from the preset rotary speed control is initiated if the current measured parameter value (P a ) exceeds or falls short of the comparison parameter (P V ), 
 optionally, a current cooling cycle (C K ) that is controlled by the preset rotary speed control is interrupted by the special cooling cycle (C D ). 
   
     
     
         2 . The method as in  claim 1 , wherein the at least one monitored comparison parameter (P V ) or one of the monitored comparison parameters (P V ) is a load (L) of the refrigerant compressor in a starting phase of a cooling cycle (C K ). 
     
     
         3 . The method as in  claim 2 , wherein the load (L) is monitored as the average load (L m ), averaged over the duration of the starting phase. 
     
     
         4 . The method as in  claim 1 , wherein the at least one monitored comparison parameter (P V ) or one of the monitored comparison parameters (P V ) is a duration of the rest cycle (C R ). 
     
     
         5 . The method as in  claim 1 , wherein
 an additional temperature (T w ) that is independent of the temperature of the cooled volume is measured,   the currently measured parameter value (P a ) or one of the currently measured parameter values (P a ) is the additional temperature (T w ),   the at least one monitored comparison parameter (P V ) or one of the monitored comparison parameters (P V ) is a comparison temperature (T V ).   
     
     
         6 . The method as in  claim 1 , wherein
 the electronic control device of the refrigerant compressor monitors to see if a power supply of the electronic control device has been interrupted,   and the special cooling cycle (C D ) is initiated if both an exceeding or falling short of the comparison parameter (P V ) by the currently measured parameter value (P a ) and a preceding interruption of the power supply are detected.   
     
     
         7 . The method as in  claim 1 , wherein the at least one measured current parameter value (P a ) is stored in the electronic control device of the refrigerant compressor over at least two operating cycles (C) as stored parameter value (P S ). 
     
     
         8 . The method as in  claim 7 , wherein an extreme value (P E ) of the stored parameter values (P S ) is selected in the electronic control device of the refrigerant compressor and the comparison parameter (P V ) is determined in dependence on the extreme value (P E ). 
     
     
         9 . The method as in  claim 7 , wherein an average value (P M ) of the stored parameter values (P S ) is calculated in the electronic control device of the refrigerant compressor and the comparison parameter (P V ) is determined in dependence on the average value (P M ). 
     
     
         10 . The method as in  claim 8 , wherein the comparison parameter (P V ) is determined by multiplying the extreme value (P E ) or the average value (P M ) by a deviation factor, wherein the deviation factor is at least 1.25. 
     
     
         11 . The method as in  claim 1 , wherein a starting rotary speed (v s ) of the refrigerant compressor is established for the cooling cycle (C K ) following the special cooling cycle (C C ) [sic; C D ] on the basis of a value stored in the electronic control device. 
     
     
         12 . The method as in  claim 1 , wherein the refrigerant compressor is operated during the special cooling cycle (C D ) so that a higher average cooling capacity is sent to the cooled volume than in the case of a comparable cooling cycle controlled in accordance with the preset rotary speed control (C K ). 
     
     
         13 . The method as in  claim 1 , wherein the refrigerant compressor is operated during the special cooling cycle (C D ) so that a defined rotary speed (v c ) is not exceeded before the end of the special cooling cycle (C D ), wherein the defined rotary speed (v c ) is at least 75%, of a maximum rotary speed of the refrigerant compressor. 
     
     
         14 . The method as in  claim 1 , wherein the refrigerant compressor is accelerated at the beginning of the special cooling cycle (C D ) to a predefined rotary speed (v c ), wherein the at least one defined rotary speed (v c ) is at least 70%, of a maximum rotary speed of the refrigerant compressor. 
     
     
         15 . An electronic control device for control of the cyclic operation of a rotary speed-variable refrigerant compressor,
 where the electronic control device is configured
 to switch the refrigerant compressor on due to a switching signal triggered by a thermostat for direct or indirect monitoring of a temperature state of a cooled volume of a refrigeration system in order to begin a cooling cycle (C K ) and to end a rest cycle (C R ), and 
 to switch the refrigerant compressor off again on the basis of an additional switching signal triggered by the thermostat in order to end the cooling cycle (C K ) and to begin a rest cycle (C R ), and 
 to control the rotary speed behavior of the refrigerant compressor during a cooling cycle (C K ) by means of a preset rotary speed control stored in the electronic control device, 
   wherein   at least one comparison parameter (P V ) is stored in the electronic control device and the electronic control device is configured
 to detect an exceeding or falling short of the comparison parameter (P V ) by a current measured parameter value (P a ), 
 to initiate a special cooling cycle (C D ) that is different from the preset rotary speed control if the current measured parameter value (P a ) exceeds or falls short of the comparison parameter (P V ), 
 optionally to interrupt a current cooling cycle ( ) [sic; (C K )] controlled by the preset rotary speed control in order to start the special cooling cycle ( ) [sic; (C D )]. 
   
     
     
         16 . The electronic control device as in  claim 15 , wherein the electronic control device is configured to measure a load of the refrigerant compressor as the current through the refrigerant compressor and that the stored comparison parameter (P v ) and the currently measured parameter value (P a ) are loads. 
     
     
         17 . The electronic control device as in  claim 15 , wherein the electronic control device is configured to determine a duration of the rest cycle (C R ) and that the stored comparison parameter (P v ) and the currently measured parameter value (P a ) are the duration of a rest cycle (C R ). 
     
     
         18 . The electronic control device as in  claim 15 , wherein the electronic control device is connected to a temperature measuring device for measurement of an additional temperature (T w ) that is independent of the temperature of the cooled volume,
 and that the stored comparison parameter (P v ) is a comparison temperature (T v ) and the currently measured parameter value (P a ) is the additional temperature (T w ).   
     
     
         19 . The electronic control device as in  claim 18 , wherein the temperature measuring device is a component of the electronic control device of the refrigerant compressor or that the temperature measuring device is disposed on a housing of the refrigerant compressor. 
     
     
         20 . The electronic control device as in  claim 15 , wherein the electronic control device is configured
 to detect an interruption of the power supply   and   to initiate a special cooling cycle (C D ) if both an exceeding or falling short of the comparison parameter (P V ) by the currently measured parameter value (P a ) and a preceding interruption of the power supply were detected.   
     
     
         21 . A module comprising
 a rotary speed-variable refrigerant compressor with an electric drive unit and a piston-cylinder unit that can be driven by the electric drive unit for compression of refrigerant;   an electronic control device as in  claim 15  for control of the cyclic operation of the rotary speed-variable refrigerant compressor.   
     
     
         22 . The method as in  claim 3 , wherein the duration of the starting phase is between 10 s and 90 s. 
     
     
         23 . The method as in  claim 22 , wherein the duration of the starting phase is between 40 s and 70 s. 
     
     
         24 . The method as in  claim 8 , wherein the comparison parameter (P V ) is determined in dependence on the extreme value (P E ), which corresponds to a maximum value of the extreme value (P E ). 
     
     
         25 . The method as in  claim 9 , wherein the comparison parameter (P V ) is determined in dependence on the average value (P M ), which corresponds to the average value (P M ). 
     
     
         26 . The method as in  claim 10 , wherein the deviation factor is at least 1.50. 
     
     
         27 . The method as in  claim 26 , wherein the deviation factor is 1.75. 
     
     
         28 . The method as in  claim 26 , wherein the deviation factor is 2.0. 
     
     
         29 . The method as in  claim 13 , wherein the defined rotary speed (v c ) is at least 85% of a maximum rotary speed of the refrigerant compressor. 
     
     
         30 . The method as in  claim 29 , wherein the defined rotary speed (v c ) is at least 90% of a maximum rotary speed of the refrigerant compressor. 
     
     
         31 . The method as in  claim 30 , wherein the defined rotary speed (v c ) is between 95% and 100% of a maximum rotary speed of the refrigerant compressor. 
     
     
         32 . The method as in  claim 14 , wherein the at least one defined rotary speed (v c ) is more than at least 80% of a maximum rotary speed of the refrigerant compressor. 
     
     
         33 . The method as in  claim 32 , wherein the at least one defined rotary speed (v c ) is at least 90% of a maximum rotary speed of the refrigerant compressor. 
     
     
         34 . The method as in  claim 33 , wherein the at least one defined rotary speed (v c ) is between 95% and 100% of a maximum rotary speed of the refrigerant compressor. 
     
     
         35 . A module comprising
 a rotary speed-variable refrigerant compressor with an electric drive unit and a piston-cylinder unit that can be driven by the electric drive unit for compression of refrigerant;   an electronic control device for control of the cyclic operation of the rotary speed-variable refrigerant compressor as in the method of  claim 1 .