Control system and method for reciprocating compressors
View Patent ↗A control system for hermetic cooling compressor includes a reciprocating compressor ( 3 ) and an electronic control ( 2 ) for the reciprocating compressor ( 3 ). The electronic control ( 2 ) is configured for, after commanding the turning off of the reciprocating compressor ( 3 ), detecting whether the turn velocity ( 23 ) of the turning axle ( 10 ) is below a predefined velocity level, and then applying a braking torque ( 36 ) that causes deceleration of the turning axle ( 10 ) before completing the next turn of the turning axle ( 10 ), in case the turn velocity ( 23 ) detected is below the velocity level ( 34 ).
1. A cooling compressor control system comprising:
an electronic control ( 2 ); and
a reciprocating compressor ( 3 ) comprising a mechanical assembly ( 12 ) including a compression mechanism ( 8 ), said compression mechanism comprising a reciprocating piston ( 15 ) coupled to a turning axle ( 10 ), and said mechanical assembly ( 12 ) further comprising a motor ( 9 ) that rotates the turning axle ( 10 ) to reciprocate the piston ( 15 );
wherein
the electronic control ( 2 ) is configured to detect a rotation turn velocity ( 33 ) of the compression mechanism ( 8 ) during a stopping process of the reciprocating compressor ( 3 ) and to apply a braking torque ( 36 ) to the mechanical assembly ( 12 ) after detecting that the rotation turn velocity ( 33 ) is below a predefined velocity level ( 34 ); and
wherein the electronic control is adapted to determine whether the rotation turn velocity is below the predefined velocity level by detecting a period that the compression mechanism needs to carry out a movement and to compare the period with a maximum reference time, the maximum reference time being related with the period which the compression mechanism needs to carry out the movement at the predefined velocity level.
2. A system according to claim 1 , wherein the electronic control ( 2 ) is adapted to apply the braking torque ( 36 ) continuously until the mechanical assembly ( 12 ) stops.
3. A system according to claim 1 , wherein the predefined velocity level ( 34 ) is configured to guarantee that an inertia of the mechanical assembly ( 12 ) will be capable of carrying out a complete compression cycle.
4. A system according to claim 3 , wherein the application of the braking torque ( 36 ) is initiated at a next moment ( 35 ) after a compression cycle has been completed.
5. A system according to claim 4 , wherein the application of the braking torque ( 36 ) is finished at a moment when the new compression cycle begins.
6. A system according to claim 1 , wherein the braking torque ( 36 ) is configured for a deceleration of the rotation turn velocity ( 33 ).
7. A system according to claim 6 , wherein the rotation turn velocity ( 33 ) of the compression mechanism ( 8 ) has a zero value at a moment when a new compression cycle begins.
8. A system according to claim 1 , wherein the braking torque ( 36 ) has a direction opposite to that of the rotation turn velocity ( 33 ).
9. A control method for a hermetic cooling reciprocating compressor ( 2 ), comprising the steps of:
(a) detecting a rotation turn velocity ( 33 ) of a mechanical assembly ( 12 ) that comprises a compression mechanism ( 8 ) and a motor ( 9 ) during a stopping process of the reciprocating compressor ( 3 ), said compression mechanism comprising a reciprocating piston ( 15 ) coupled to a turning axle ( 10 ), said turning axle ( 10 ) driven by said motor ( 9 );
(b) comparing the rotation turn velocity ( 33 ) with a predefined velocity level ( 34 ); and
(c) applying a braking torque ( 36 ) for a deceleration of the mechanical assembly ( 12 ) after detecting that the rotation turn velocity ( 33 ) is below the predefined velocity level ( 34 );
wherein the step (a) detects a period which the compression mechanism ( 8 ) needs to carry out a movement and the step (b) compares the period with a maximum reference time related with the period which the compression mechanism ( 8 ) needs to carry out the movement at the predefined velocity level ( 34 ) to determine the rotation turn velocity ( 33 ).
10. A method according to claim 9 , wherein the predefined velocity level ( 34 ) guarantees that an inertia of the mechanical assembly ( 12 ) will be capable to carry out a complete compression cycle.
11. A method according to claim 10 , wherein the step (c) is initiated at a moment ( 35 ) following completion of a compression cycle.
12. A method according to claim 11 , wherein the step (c) is finished at a moment when the at least one compression cycle begins.
13. A method according to claim 9 , wherein the step (c) is configured to cause deceleration of the rotation turn velocity ( 33 ).
14. A method according to claim 13 , wherein the step (c) is configured so that the rotation turn velocity ( 33 ) of the compression mechanism ( 8 ) has a zero value at a moment when the new compression cycle begins.
15. A method according to claim 9 , wherein the step (c) is carried out by applying the braking torque ( 36 ) contrary to the rotation turn velocity ( 33 ).
16. A method according to claim 9 , wherein the step (c) is carried out by applying the braking torque ( 36 ) continuously until the mechanical assembly ( 12 ) stops.