Title of Invention

METHOD FOR OPTIMIZING THE OPERATION OF A PLURALITY OF COMPRESSOR ASSEMBLIES OF A NATURAL - GAS COMPRESSION STATION

Abstract A method for optimizing the operation of a plurality of compressor assemblies of a natural-gas compression station, in which, after the start of a second or a further compressor assembly, the rotational speeds of the running compressor assemblies are run in a fixed rotational speed ratio with respect to characteristic- map data filed for each compressor assembly, thereafter this fixed rotational speed ratio is varied by means of an equal-percentage throughflow quantity adjustment via the rotational speed, until surge prevention valves of the natural- gas compression station are closed, thereafter the operating points of the compressor assemblies in their characteristic maps are lead as far as possible toward the maximum efficiency line, thereafter, in a continuous operating mode of the natural-gas compression station, set optimum rotational-speed values are determined by means of a reciprocal trimming or mutually coordinated variation of the set rotational speed values of the compressor assemblies, with the fuel consumption of the natural-gas compression station being kept under observation, and, on the basis of set optimum rotational speed values thus determined, the stored fixed rotational speed ratio is adjusted and stored.
Full Text Description
Method for optimizing the operation of a plurality of
compressor assemblies of a natural-gas compression
station
The invention relates to a method for optimizing the
operation of a plurality of compressor assemblies of a
natural-gas compression station.
Natural-gas compression stations of this kind are
controlled or regulated by means of what may be
referred to as station automatics, the task of which is
to implement as actual values the desired values,
predetermined "by" a central dispatching unit, for
specific characteristic values of the natural-gas
compression station. The station throughflow, which is
the throughflow quantity through the natural-gas
compression station, the suction pressure on the inlet
side of the natural-gas compression station, the final
pressure on the outlet side of the natural-gas
compression station or the final temperature on the
outlet side of the natural-gas compression station may
function as desired values of this kind.
The compressor assemblies of such natural-gas
compression stations often differ from one another both
in the very differently designed drive machines and in
different rotors, by means of which the gas transport
through the natural-gas compression station is carried
out.
The subject on which the invention is based is to make
available a method for optimizing the operation of a
plurality of compressor assemblies of a natural-gas
compression station, by means of which method the
interaction of a plurality of compressor assemblies of
the natural-gas compression station is automated in an
optimum way by a regulation of the characteristic maps
of the compressor assemblies, the characteristic maps
of the compressor assemblies being capable of having
considerable differences from one another.
This object is achieved, according to the invention, in
that, after the start of a second or a further
compressor assembly of the natural-gas compression
station, the rotational speeds of the running
compressor assemblies are run in a fixed rotational
speed ratio with respect to characteristic-map data
filed for each compressor assembly, thereafter this
fixed rotational speed ratio is varied by means of an
equal-percentage throughflow quantity adjustment via
the rotational speed, until surge prevention Valves of
the natural-gas compression station are closed,
thereafter the operating points of the compressor
assemblies in their characteristic maps are lead as far
as possible toward the maximum efficiency line,
thereafter, in. a continuous operating mode of the
natural-gas compression station, optimum rotational-
speed desired values are determined by a reciprocal
trimming or mutually coordinated variation of the
rotational-speed desired values of the compressor
assemblies, the fuel consumption of the natural-gas
compression station being kept under observation, and,
on the basis of optimum rotational-speed desired values
thus determined, the stored fixed rotational speed
ratio is adjusted and stored.
By the rotational-speed desired values of the various
compressor assemblies being trimmed, an optimum
position of the individual operating points in the
various characteristic maps of the compressor
assemblies and therefore a minimum use of fuel for the
compressor output demanded by the natural-gas
compression station are achieved. By virtue of the
minimization of fuel consumption achieved in this way,
the emission of the exhaust-gas quantity and therefore
the emission of NOx and CO2 are reduced.
The above-outlined sequence control for the purpose of
minimizing the fuel consumption of the natural-gas
compression station can advantageously be implemented
on the basis of the automation program installed for
operating the natural-gas compression station, so that
there is no need for a separate optimization program or
any other program module. In the method according to
the invention, optimization, taking into account the
minimization of the fuel consumption of the natural-gas
compression station, is carried out
by means of mutually coordinated characteristic-curve
displacements of the individual compressor assemblies.
In an advantageous embodiment of the method according
to the invention, the rotational-speed desired values
for the individual compressor assemblies are
transmitted by a station controller of the natural-gas
compression station to individual rotational-speed
controllers of the individual compressor assemblies,
the controlled variable used for the station controller
being that controlled variable of a plurality of
controlled variables which has the lowest positive
control deviation.
The station throughflow or throughflow quantity, the
suction pressure, the final pressure or the final
temperature of the natural-gas compression station may
function as controlled variables.
The trimming or the mutually coordinated variation of
the rotational-speed desired values of the individual
compressor assemblies of the natural-gas compression
station, taking into account the minimization of the
fuel consumption of the entire natural-gas compression
station, can advantageously be carried out by means of
an optimization computer arranged between the station
controller and the individual rotational-speed
controllers of the individual compressor assemblies.
The invention is explained in more detail below with
reference to an embodiment,
Fig. 1 showing compressor characteristic maps of
compressor assemblies, and
Fig. 2 showing an operating and observation surface
of a PC monitor used for controlling a
compressor station.
A natural-gas compression station has a multiplicity of
individual compressor assemblies which have at least
partially different
drive machines and different rotors, this being
attributable, for example, to the fact that compressor
assemblies are designed for covering basic-load
operation and compressor assemblies are designed for
covering peak-load operation.
In order to optimize the operation of a plurality of
compressor assemblies of a natural-gas compression
station, after the successful start of a further or
additional compressor assembly of the natural-gas
compression station, a station controller of the
natural-gas compression station will run the rotational
speeds of the now operative compressor assemblies of
the natural-gas compression station in a fixed
rotational speed ratio to the characteristic-map data
filed for each compressor assembly.
This fixed rotational-speed ratio is subsequently
varied by means of an equal-percentage throughflow
quantity adjustment via the rotational speed of the
individual compressor assemblies, until surge
prevention valves present in the natural-gas
compression station are closed. Due to the closing of
the surge prevention valves, a first fuel reduction
takes place during the operation of the natural-gas
compression station. What is achieved at the same time
by the closing of the surge prevention valves is that
the transport gas to be compressed or transported by
means of the natural-gas compression station is heated
to a lesser extent, with the result that, in turn, the
energy balance at the natural-gas compression station
has a more favorable configuration.
When all the surge prevention valves of a natural-gas
compression station are closed, the operating points of
the individual compressor assemblies in their
characteristic maps are lead toward their maximum
efficiency line, in so far as this is possible.
During the subsequent continuous operating mode of the
natural-gas compression station, optimum values for the
rotational-speed desired values of the individual
compressor assemblies are then searched for by means of
a reciprocal trimming or mutually coordinated variation
of the rotational-speed desired values of the
individual compressor assemblies and
the observation of the overall fuel consumption of the
natural-gas compression station. After these optimum
rotational-speed desired values are determined for the
individual compressor assemblies, the abovementioned
fixed rotational speed ratio with respect to the filed
characteristic-map data is adjusted according to the
optimum rotational-speed desired values determined and
is then stored.
The controlled variable having the lowest positive
control deviation functions as the controlled variable
for the station controller of the natural-gas
compression station. The rotational-speed desired value
for the individual compressor assemblies is made
available on the output side of the station controller.
The transfer of these rotational-speed desired values
made available on the output side of the station
controller to the individual compressor assemblies is
carried out by rotational-speed controllers which are
assigned to the individual control units of the
individual compressor assemblies.
In order to take into account the different design of
the individual compressor assemblies, the rotational-
speed desired values, before being transmitted to the
rotational-speed controllers of the individual
compressor assemblies, are trimmed by an optimization
computer connected between the station controller and
these individual rotational-speed controllers.
WE CLAlM:
1. A method for optimizing the operation of a plurality of compressor
assemblies of a natural-gas compression station, in which, after the start
of a second or a further compressor assembly, the rotational speeds of the
running compressor assemblies are run in a fixed rotational speed ratio
with respect to characteristic-map data filed for each compressor
assembly, thereafter this fixed rotational speed ratio is varied by means of
an equal-percentage throughflow quantity adjustment via the rotational
speed, until surge prevention valves of the natural-gas compression
station are closed, thereafter the operating points of the compressor
assemblies in their characteristic maps are lead as far as possible toward
the maximum efficiency line, thereafter, in a continuous operating mode of
the natural-gas compression station, set optimum rotational-speed values
are determined by means of a reciprocal trimming or mutually coordinated
variation of the set rotational speed values of the compressor assemblies,
with the fuel consumption of the natural-gas compression station being
kept under observation, and, on the basis of set optimum rotational speed
values thus determined, the stored fixed rotational speed ratio is adjusted
and stored.
2. The method as claimed in claim 1, the sequence control of which is
implemented on the basis of the automation program installed for
operating the natural-gas compression station.
3. The method as claimed in claim 1 or 2, wherein the rotational-speed
desired values for the compressor assemblies are transmitted by a station
controller to rotational-speed controllers of the compressor assemblies,
the controlled variable used for the station controller being that controlled
variable of a plurality of controlled variables which has the lowest positive
control deviation.
4. The method as claimed in one of claims 1 to 4, wherein the station
throughflow or the throughflow quantity, the suction pressure, the final
pressure or the final temperature of a natural-gas compression station
function as controlled variables.
5. The method as claimed in claim 3 or 4, wherein the trimming or the
mutually coordinated variation of the rotational-speed desired values of
the compressor assemblies of the natural-gas compression station is
carried out by means of an optimization computer arranged between the
station controller and the rotational-speed controllers of the compressor
assemblies.
A method for optimizing the operation of a plurality of compressor assemblies of
a natural-gas compression station, in which, after the start of a second or a
further compressor assembly, the rotational speeds of the running compressor
assemblies are run in a fixed rotational speed ratio with respect to characteristic-
map data filed for each compressor assembly, thereafter this fixed rotational
speed ratio is varied by means of an equal-percentage throughflow quantity
adjustment via the rotational speed, until surge prevention valves of the natural-
gas compression station are closed, thereafter the operating points of the
compressor assemblies in their characteristic maps are lead as far as possible
toward the maximum efficiency line, thereafter, in a continuous operating mode
of the natural-gas compression station, set optimum rotational-speed values are
determined by means of a reciprocal trimming or mutually coordinated variation
of the set rotational speed values of the compressor assemblies, with the fuel
consumption of the natural-gas compression station being kept under
observation, and, on the basis of set optimum rotational speed values thus
determined, the stored fixed rotational speed ratio is adjusted and stored.

Documents:

502-KOLNP-2004-FORM-27.pdf

502-kolnp-2004-granted-abstract.pdf

502-kolnp-2004-granted-claims.pdf

502-kolnp-2004-granted-correspondence.pdf

502-kolnp-2004-granted-description (complete).pdf

502-kolnp-2004-granted-drawings.pdf

502-kolnp-2004-granted-examination report.pdf

502-kolnp-2004-granted-form 1.pdf

502-kolnp-2004-granted-form 18.pdf

502-kolnp-2004-granted-form 2.pdf

502-kolnp-2004-granted-form 3.pdf

502-kolnp-2004-granted-form 5.pdf

502-kolnp-2004-granted-gpa.pdf

502-kolnp-2004-granted-reply to examination report.pdf

502-kolnp-2004-granted-specification.pdf


Patent Number 226705
Indian Patent Application Number 502/KOLNP/2004
PG Journal Number 52/2008
Publication Date 26-Dec-2008
Grant Date 24-Dec-2008
Date of Filing 16-Apr-2004
Name of Patentee SIEMENS AKTIENGESELLSCHAFT
Applicant Address WITTELSBACHERPLATZ 2, 80333 MUENCHEN
Inventors:
# Inventor's Name Inventor's Address
1 LAU DIETER LEIPZIGER STR. 13, 45472 MULHEIM
PCT International Classification Number F04D 27/02
PCT International Application Number PCT/DE2002/03855
PCT International Filing date 2002-10-11
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 101 51 032.2 2001-10-16 Germany