Starting method for a piston compressor and piston compressor

Abstract

In an effective method for starting a piston compressor which is easy to implement, and a piston compressor suitable for carrying out the method, there is provision, in a resetting phase, for driving a piston of the piston compressor in the direction of a compression point of the piston position by the application of a resetting drive moment. The resetting drive moment being maintained until the piston has reached a starting position by overstepping a steady-state point as a result of displacement of fluid out of the compression space, formed between the piston and a corresponding pressure cylinder, through at least one leakage point. In a subsequent acceleration phase, the piston is then accelerated out of the starting position into an operational direction of rotation with a starting drive moment.

1 . A method for starting a piston compressor, which comprises the steps of: 
 during a resetting phase, driving a piston of the piston compressor in a direction of a compression point of a piston position by applying a resetting drive moment;    maintaining the resetting drive moment until the piston reaches a starting position by overstepping a steady-state point as a result of displacement of fluid out of a compression space, formed between the piston and a corresponding pressure cylinder, through at least one leakage point; and    during an acceleration phase, accelerating the piston out of the starting position into an operational direction of rotation with a starting drive moment.    
   
   
       2 . The method according to  claim 1 , which further comprises directing the resetting drive moment opposite to the operational direction of rotation.  
   
   
       3 . The method according to  claim 1 , which further comprises selecting the starting position in an angular range of the piston position of +/−30° with respect to the compression point.  
   
   
       4 . The method according to  claim 1 , which further comprises exciting a stator field of a motor driving the piston compressor at a predetermined angular speed of between 1 and 10 revolutions per minute for a predetermined time span of between 3 and 30 seconds for generating the resetting drive moment.  
   
   
       5 . The method according to  claim 1 , which further comprises setting said starting drive moment to correspond to a predetermined maximum drive moment.  
   
   
       6 . A piston compressor, comprising: 
 a pressure cylinder;    a drive shaft;    a motor driving said drive shaft;    a piston being moved in said pressure cylinder by said drive shaft being driven by said motor; and    a control unit for activating said motor, said control unit being configured to: 
 in a resetting phase, predetermine a resetting drive moment, by which said piston being driven in a direction of a compression point of a piston position;  
 maintain the resetting drive moment until said piston reaches a starting position by overstepping a steady-state point as a result of displacement of fluid out of a compression space, formed between said piston and said pressure cylinder, through a leakage point; and  
 in an acceleration phase, predetermine a starting drive moment, by which said piston is accelerated out of the starting position into an operational direction of rotation.