1. A procedure for controlling the useful life of the gas turbines of a plant by means of a production plant (10) comprising a series of production trains (15) and an auxiliary gas generator group (40), each production train of said series of trains (15) being in turn equipped with a series of gas turbine groups (20), each of which in turn includes a gas generator, characterized in that it comprises the following phases:
a) creating a succession (20\u2032, 20\u2033, 20\u2032\u2033 . . . ) of gas generator groups of gas turbines (20) to be subjected to maintenance;
b) substituting the first gas generator group of gas turbines (20\u2032) of said succession (20\u2032, 20\u2033, 20\u2032\u2033 . . . ) with said auxiliary gas generator group (40), to keep the production plant (10) functioning almost continuously;
c) controlling the first substituted gas generator group of gas turbines (20\u2032), by subjecting it to ordinary maintenance operations;
d) substituting the second gas generator group of gas turbines (20\u2033) of said succession (20\u2032, 20\u2033, 20\u2032\u2033 . . . ) with said first controlled gas generator group of gas turbines (20\u2032);
e) controlling the second substituted gas generator group of gas turbines (20\u2033), by subjecting it to ordinary maintenance operations;
f) repeating said phases b), c) d) and e) for all the gas generator groups of gas turbines (20) of said succession (20\u2032, 20\u2033, 20\u2032\u2033 . . . ) until all the gas generator groups of the gas turbines (20) of said plant (10) have been subjected to control and maintenance.
2. The procedure for controlling the useful life of the gas turbines of a plant according to claim 1, characterized in that during the substitution phases of the gas generator groups of gas turbines of said succession, only the group of gas turbines (20) to be substituted is stopped.
3. The procedure for controlling the useful life of the gas turbines of a plant according to claim 1 or 2, characterized in that during the substitution operations of said gas generator groups of gas turbines (20), the group to be substituted is only stopped for the minimum time necessary for effecting the substitution.
4. The procedure for controlling the useful life of the gas turbines of a plant according to any of the previous claims, characterized in that at the end of phase c), the first controlled gas generator group of gas turbines (20\u2032) substitutes the second gas generator group of gas turbines (20\u2033).
5. The procedure for controlling the useful life of the gas turbines of a plant according to any of the previous claims, characterized in that said production plant (10) comprises four production trains (15).
6. The procedure for controlling the useful life of the gas turbines of a plant according to any of the previous claims, characterized in that each production train of said series of trains (15) comprises two groups of gas turbines (20) for liquefying gas, by compressioncooling.
7. The procedure for controlling the useful life of the gas turbines of a plant according to any of the previous claims, characterized in that each gas generator group comprises at least a number of gas generators equal to the number of gas turbines present in the group of gas turbines.
8. The procedure for controlling the useful life of the gas turbines of a plant according to claim 7, characterized in that said gas turbine (20) is a \u201cheavy duty\u201d gas turbine.
9. The procedure for controlling the useful life of the gas turbines of a plant according to claim 1, characterized in that said gas generator comprises a power turbine (34) and a discharge outlet 36.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A transmission control method wherein a controller performs the steps comprising:
applying a reference a stroke pressure to an oncoming element while executing a downshift;
decreasing stroke pressure for a second downshift if a delta between a maximum and minimum rate of change of transmission output speed is greater than a reference delta during the downshift;
when said delta is less than the reference delta, using a magnitude of turbine speed flair to adjust stroke pressure for the second downshift.
2. The method of claim 1 further comprising:
after applying the reference stroke pressure, increasing pressure in the oncoming element greater than the reference stroke pressure;
determining the stroke pressure adjustment from data produced while pressure in the oncoming element is greater than the reference stroke pressure.
3. The method of claim 1 further comprising:
increasing the turbine speed toward a synchronous speed for a target gear.
4. The method of claim 1 wherein the stroke pressure adjustment varies with a magnitude of a difference between the flare and a reference flare.
5. The method of claim 1 wherein the delta is determined from data produced during the downshift before the turbine speed reaches a synchronous speed for the target gear.
6. The method of claim 1 wherein the decrease in stroke pressure for the second downshift varies with a magnitude of a difference between the delta and the reference delta.
7. The method of claim 1 wherein a change in stroke pressure for the second downshift may be zero.
8. A transmission control method wherein a controller performs the steps comprising:
applying a reference stroke pressure to an oncoming control element while executing a downshift to a target gear;
determining a delta between a maximum and a minimum rate of change of a speed of an output of the transmission;
when the delta is greater than a reference delta, determining a stroke pressure adjustment in response to the delta;
executing a second downshift while applying to the oncoming element an adapted stroke pressure that is a sum of the second stroke pressure adjustment and the reference stroke pressure.
9. The method of claim 8 wherein the delta is determined from data produced during the downshift before the turbine speed reaches a synchronous speed for the target gear.
10. The method of claim 8 wherein the stroke pressure adjustment varies with a magnitude of the delta.
11. The method of claim 8 wherein the stroke pressure adjustment may be zero.
12. The method of claim 8 further comprising:
determining a second stroke pressure adjustment in response to a turbine speed flare during the downshift;
when the delta is less than a reference delta, executing a second downshift while applying to the oncoming element an adapted stroke pressure that is a sum of the second stroke pressure adjustment and the reference stroke pressure.
13. The method of claim 12 further comprising:
after applying the reference stroke pressure, increasing pressure in the oncoming element greater than the reference stroke pressure;
determining the second stroke pressure adjustment from data produced while pressure in the oncoming element is greater than the reference stroke pressure.
14. The method of claim 12 further comprising:
increasing the turbine speed toward a synchronous speed for the target gear.
15. The method of claim 12 wherein the second stroke pressure adjustment varies with a magnitude of the flare.
16. A system for controlling a transmission downshift comprising:
a turbine;
an oncoming control element;
an output;
a controller configured to apply a reference stroke pressure to the oncoming control element while executing a downshift to a target gear, to decrease stroke pressure for a second downshift if a delta between a maximum and minimum rate of change of transmission output speed is greater than a reference delta during the downshift, and if said delta is less than the reference delta, to use a magnitude of turbine speed flair to adjust stroke pressure for the second downshift.
17. The system of claim 16 wherein the controller is further configured to determine a maximum delta between a maximum and a minimum rate of change of a speed of the output; to determine a stroke pressure adjustment in response to the delta, if the delta is greater than a reference delta; and to execute the second downshift while applying to the oncoming element an adapted stroke pressure that is a sum of the second stroke pressure adjustment and the reference stroke pressure.