TITLE :
SINGLE SYSTEM WITH INTEGRATED COMPRESSOR AND PUMP
AND METHOD
BACKGROUND
TECHNICAL FIELD
Embodiments of the subject matter disclosed herein generally relate to
methods and systems and, more particularly, to mechanisms and techniques for
integrating a compressor part and a pump part in a single system for
compressing and pumping a given fluid.
DISCUSSION OF THE BACKGROUND
During the past years the increased reliance on petrochemical products
has generated not only a large increase in pollutant (e.g., CO2) emissions but
also a need to have more compressors, pumps and other machinery that are
used for processing oil and gas derivative products.
For example, in the field of Power Generation a large amount of CO2
emissions are produced. As the world is becoming more sensitive to the
polluting emissions and the governments are moving towards a system that
penalizes these emissions into the environment, it is more acute than ever to
develop technologies that reduce the amount of pollution, the so-called green
technologies. In a different field, Enhanced Oil Recovery (EOR, which refers
to techniques for increasing the amount of crude oil that can be extracted from
an oil field) the need for transporting CO2 and/or a CO2 mixture in a more
efficient and reliable way is also important for the industry and for the
environment. According to EOR, 002 and/or CO2 mixture from a storage
facility is provided to a drilling location, either onshore or offshore for being
pumped underground for removing the oil. As such, the transportation of CO2
and/or C02 mixture s important for this field. With regard to power generation,
the reduction of CO2 emissions is challenging as this fluid has a high molecular
weight and its critical point is at a very low pressure (74 bar) at ambient
temperature. In order to remove the C02 that is usually produced as a gas
by power generation, the C02 needs to be separated from the other
pollutants and/or substances that are present in the exhaust from the power
plant. This step is traditionally called capture. After capturing the 002, the
gas needs to be compressed to arrive at a predetermined pressure, cooled
down to change from gas phase to a dense phase, e.g., liquid phase, and then
transported in this denser phase to a storage location. As will be discussed
later, the dense phase depends on the type of fluid, the amount of impurities in
the fluid and other parameters. However, there is no unique parameter that
can quantitatively describe the dense phase for a fluid in general, unless an
accurate composition of the fluid is known. The same process may be used
for EOR, where the 002 and/or C02 mixture needs to be captured and then
compressed and transported to the desired location for reinjection.
Thus, conventionally, after the capturing phase, a compressor is used to bring
the initial C02 in the gas phase to a dense phase or a liquid phase.
Afterwards, the C02 is feed to a pump that transports the fluid in the dense
or liquid phase to a storage facility or to another desired location for
reinjection. It is noted that for both the pump and the compressor to
efficiently process the C02, certain pressures and temperatures of the 002
in the gas and dense/liquid phases have to be achieved as the efficiencies of
the compressor and pump are sensitive to them. Therefore, traditional
compressors and pumps need to be fine-tuned with respect to each other such
that the precise phase of 002 is transferred from the compressor to the pump.
However, as the compressor and pump are traditionally manufactured by
different providers, the matching of these two elements may be time intensive,
requiring a lot of coordination between the manufacturers. Further, the existent
systems that use standalone compressors and standalone pumps have a
large footprint, which may be expensive.
Accordingly, it would be desirable to provide systems and methods that avoid
the afore-described problems and drawbacks.
?
SUMMARY
According to one exemplary embodiment, there is a system for compressing
a fluid in a gas phase and for pumping the fluid in a dense phase. The
system includes a compressor part having at least one impeller configured to
compress the fluid in the gas phase; a compressor part inlet connected to the
compressor part and configured to receive the fluid in the gas phase and to
provide the fluid to the at least one impeller; a compressor part outlet
configured to provide the fluid in the gas phase at a density equal to or
larger than a predetermined density; a temperature changing device
connected to the compressor part outlet and configured to change the
fluid to the dense phase; a pump part having at least one impeller configured
to pump the fluid in the dense phase; a pump part inlet configured to
receive the fluid in the dense phase from the compressor part outlet; a pump
part outlet configured to output the fluid in the dense phase from the
system; a single bull gear configured to rotate around an axial axis
with a predetermined speed; plural pinions contacting the single bull gear and
configured to rotate with predetermined speeds, different from each other,
each pinion being configured to activate a corresponding compressor part
impeller, and a pump shaft extending from the pump part and configured to
engage the single bull gear to rotate the at least one impeller of the pump
part. The at least one impeller of the compressor part has a different speed
than the at least one impeller of the pump part, and the dense phase is
defined by having a density larger than the predetermined density.
According to another exemplary embodiment, there is a method for
compressing a fluid in a gas phase and for pumping the fluid in a dense
phase with a system including a compressor part and a pump part, the
compressor part having at least one compressor part impeller and the pump
part having at least one pump part impeller. The method includes
receiving at a compressor part inlet of the compressor part the fluid in the
gas phase; compressing the fluid in the gas phase in one or more stages of
the compressor part such that the fluid emerges at a compressor part
outlet of the compressor part as a fluid in the gas phase at a density equal
to or larger than a predetermined density; transforming a phase of the fluid
to the dense phase by cooling the fluid after exiting the compressor part;
receiving the fluid in the dense phase at a pump part inlet of the pump
part; pumping the fluid in the dense phase through one or more stages of the
pump part such that the fluid emerges at a pump part outlet of the pump part
having a higher pressure than at the pump part inlet; and rotating a single
bull gear in order to activate all of the at least one or more compressor
stages and the at least one or more pump stages. The dense phase is
defined by the fluid having a density larger than the predetermined
density.
According to still another exemplary embodiment, there is a computer
readable medium including computer executable instructions, wherein the
instructions, when executed, implement a method for compressing a fluid in
a gas phase and for pumping the fluid in a dense phase with a system
including a compressor part and a pump part, the compressor part having
at least one compressor part impeller and the pump part having at least
one pump part impeller. The method includes the steps recited in the
previous paragraph.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of
the specification, illustrate one or more embodiments and, together
with the description, explain these embodiments. In the drawings:
Figure 1 is a general view of a system having an integrated compressor and
pump
according to an exemplary embodiment;
Figure 2 is a schematic diagram of a system having an integrated
compressor and
pump according to an exemplary embodiment;
Figure 3 illustrates a phase diagram of a fluid that is compressed by the
compressor and pumped by the pump at certain temperatures and pressures
according to an exemplary embodiment;
Figure 4 is a schematic diagram of a pump part connected to a bull gear
that activates a compressor part according to an exemplary embodiment;
Figure 5 is a side view of a system having the integrated compressor and
pump according to an exemplary embodiment;
Figure 6 is a schematic diagram of a pump part of the system according to
an exemplary embodiment;
Figure 7 is a schematic diagram of a system having an integrated compressor
and pump and a control system; and
Figure 8 is a flow chart illustrating a method for compressing and transporting
a fluid according to an exemplary embodiment.
DETAILED DESCRIPTION
The following description of the exemplary embodiments refers to the
accompanying drawings. The same reference numbers in different drawings
identify the same or similar elements. The following detailed description does
not limit the invention. Instead, the scope of the invention is defined by the
appended claims. The following embodiments are discussed, for simplicity,
with regard to the terminology and structure of a compressor and pump used
for C02. However, the embodiments to be discussed next are not limited to this
fluid, but may be applied to other fluids.
Reference throughout the specification to "one embodiment" or "an
embodiment" means that a particular feature, structure, or characteristic
described in connection with an embodiment is included in at least one
embodiment of the subject matter disclosed. Thus, the appearance of the
phrases "in one embodiment" or "in an embodiment" in various places
throughout the specification is not necessarily referring to the same
embodiment. Further, the particular features, structures or characteristics
may be combined in any suitable manner in one or more
embodiments.
According to an exemplary embodiment, there is a single system that includes
a compressor part and a pump part. The single system is configured to
take as input a fluid in a gas phase, transform it to a fluid in a dense phase
(or liquid phase) and transport the fluid in the dense phase to a desired
location. The dense phase may be defined by a density, pressure and
temperature of the fluid. The density, which is predetermined for each fluid,
depends, among other things, on the composition of the fluid. It is noted that
the fluid in the dense phase may be a gas but so dense that behaves like a
liquid when pumped. For this reason, it is desired to supply the fluid in the
dense phase or the liquid phase to the pump part. The system may have a single
bull gear that drives both the compressor part and the pump part. Such a
system may have a smaller footprint than a traditional system that includes
a standalone compressor and a standalone pump as both the compressor
stages and the pump stages are formed around the bull gear. The system
may also use less power than the standalone compressor and the
standalone pump. The system may use one or more cooling devices provided,
for example, between the compressor part and the pump part for cooling the
fluid in the gas phase from the compressor to achieve the dense phase prior
to the same being supplied to the pump part. Other cooling devices may be
optionally installed between the various stages of the compressor part and/or
pump part. According to an exemplary embodiment illustrated in Figure 1, an
integrated system 10 includes a compressor part 12 and a pump part 14.
The compressor part 12 is housed in a casing 16. Inside the casing 16 there
is a gear box 18 that includes, among other things, a single bull gear 20 and
one or more pinions 22. In one application, the gear box 18 may be provided
outside casing 16. Each pinion 22 may be attached to a corresponding shaft
24 that is connected to a
corresponding compressor impeller. A shaft 23 is connected with one end to
the bull gear 20, either directly or via one or more pinions 25 or other
equivalent mechanisms and the other end of the shaft 23 enters the
pump part 14 for activating the one or more stages present in the pump
part. A gear 26 may be provided between the bull gear 20 and one or more
of the pinions 22. According to an exemplary embodiment, the stages of the
compressor part are distributed around the bull gear 20 like spikes around a
hub of a wheel while the stages of the pump part 14 are distributed in line,
along the shaft 23 as shown later, which is different from an inline
arrangement, in which the stages of the compressor and pump are all
distributed along a common shaft. Another difference between the
arrangement shown in Figure 1 and an inline arrangement is that the stages of
the system 10 may have their own rotational speed while the stages in the
inline arrangement all have a single rotational speed.
The compressor part 12 may include multiple stages, e.g., multiple impellers
that drive the desired fluid. In one application, the compressor part 12 is a
centrifugal compressor and the number of compressor impellers and
correspondingly compressor stages may be one or more. According to an
exemplary embodiment, the compressor impellers are selected to
accelerate the flowing fluid due to a centrifugal force, so that the
compressor part 12 acts as a centrifugal compressor. For example, the
embodiment shown in Figure 1 shows six stages 30-1 to 30-6, each having a
corresponding compressor impeller. Each stage has an inlet and an outlet.
The compressor part 12 has an overall compressor part inlet 32 and an
overall compressor part outlet 36. The compressor part inlet 32 s configured
to receive the fluid in the gas phase and the compressor part overall outlet
36 is configured to provide the fluid in the gas phase at an increased pressure
and/or density. For example, the input pressure may be I bar while the output
pressure may be between 10 to 1000 bar. In one application, the output
pressure may be between 10 and 120 bar. The output density may be between
100 and 500 kg/m3 for 002 having a relative low impurity content, between 0 and
5%. The pump part 14 may also include one or multiple stages, e.g., multiple
impellers that drive the fluid in the dense or liquid phase. Each stage may have
an inlet and an outlet. The pump part 14 has an overall pump part inlet and a
pump part outlet (shown later). The pump part inlet may be configured to
be connected to the overall compressor part outlet 36 to receive the fluid in
the dense phase from the compressor part. The pump part outlet may be
configured to discharge the fluid in the dense phase at a desired pressure for
transportation, for example, to a storage location. For the 002 having the
impurity noted above, a density between 400 and 800 kg/m3 is the
predetermined density that characterizes the dense phase. In other words, for
this particular purity of 002, if the density of the fluid is around or larger than
400 to 800 kg/m3 and the temperature and pressure of the fluid are above
the critical values, then the fluid is considered to be in the dense phase. As
already noted above, this value is correct for a particular purity of 002 and
thus, this value changes with the nature of the fluid and its purity.
The pump part shown in Figure 1 has the shaft 23 extending inside housing 16
of the compressor part 12 such that the bull gear 20 activates the shaft 23.
Thus, the rotation of the bull gear 20 (by a shaft 21) determines not only the
rotation of the compressor stages' pinions but also the rotation of the pump
shaft 23 and thus, the rotation of the pump part impellers. In one application,
another mechanism may be used instead of the bull gear for activating the
compressor's stages and the pump's stages. It is noted that while the bull gear
20 may rotate with a given speed, each compressor impeller may rotate with a
different speed depending on the size of the corresponding pinion. However, the
pump impellers are distributed inline, e.g., the pump part impellers have a same
speed. In other words, by using a single bull gear, the various stages of the
compressor part and the pump part may be designed such that the single
system receives as input a fluid in a gas phase and output the fluid in a
dense phase or liquid phase.
According to an exemplary embodiment, connections among the
various compressor part and pump part inlets and outlets are shown
in Figure 2.
Compressor part 12 includes six stages in this embodiment. However,
as discussed above, this number is exemplary and the compressor part may
include more or less stages as necessary for each application. The overall
inlet 32 and the overall outlet 36 of the compressor part 12 have been
shown in Figure 1.
Figure 2 shows the inlets and outlets between the different stages of
the compressor part 12. For example, after the fluid in the gas phase enters
overall inlet 32, the 1 St stage discharges the fluid, still in the gas phase, at
outlet 34-1. It is noted that outlet 34-1 is the outlet of the ISt stage while overall
outlet 36 is the outlet of the last stage and the overall outlet of the compressor
part 12. The fluid in the gas phase, having an increased pressure and
temperature at outlet 34-1, may be provided to a temperature cooling device
40-1 for reducing a temperature of the fluid in the gas phase. The number
of cooling devices used between different stages of the compressor part
may vary from application to application. The cooling device may be a cooler
(a cooler is a device that circulates water or other media at a desired
temperature around a liquid to remove heat from the liquid), a chiller (a
chiller is a machine that removes heat from a liquid via a vapor-compression or
absorption refrigeration cycle) or an expander (a device that is capable of
expanding a gas producing mechanical torque, also called a Joule-Thomson
valve).
Figure 3 illustrates the process of Figure 2 on a pressure-enthalpy or Ph
diagram. Also included in the Ph diagram are lines of constant temperature.
The lines of constant temperature are identified by corresponding
temperatures. For example, Figure 3 shows that the temperature is around
25 °C and the pressure is around 1 bar at inlet 32 and the temperature has risen
to around 120 °C and the pressure to around 5 bar at the outlet 34-1 of the first
stage. The numbers shown in Figure 3 are for explanatory purposes and are
not intended to limit the applicability of the discussed embodiments. For
simplicity, the reference numbers used for the inlets and outlets in Figure 2 are
also used in Figure 3 to show their corresponding temperatures and pressures.
Still with regard to Figure 3, the cooling device 40-1 may reduce the
temperature of the fluid after the first stage from about 120 °C to about 25
°C prior to entering the inlet 32-2 of the second stage. A separator device
42-1 may be connected between the outlet 34-1 of the first stage and the inlet
32-2 of the second stage to remove water (or other liquids) from the
compressed C02 fluid. The number of separator devices may vary from
one between each two adjacent stages to zero depending on the application.
The second stage expels the fluid still in the gas phase at outlet 34-2, and
after passing through an optional second temperature cooling device 40-
2, the gas arrives at the inlet 32-3 of the third stage. The fluid in the gas
phase continues to pass from stage to stage, e.g., through elements 34-3, 32-
4, 34-4, 32-5, 34-5, and 32-6 until the fluid in the gas phase exits the overall
outlet 36 at a high pressure. Figure 3 shows that the temperatures and
pressures of the fluid in the gas phase are maintained close to but outside of
the dome 50. According to an exemplary embodiment, the compressor part
12 may be designed to process a fluid in the gas phase by preventing the
fluid from entering the dome 50, as this may result in loss of compressor
performance or even damage thereto.
A critical point 52 of the fluid, in this case C02, is shown on top of the dome 50
and its exemplary reference pressure and temperature values are listed in
Figure 3. A critical point is a point at which boundaries between phases of the
fluid ceases to exist. Points having pressures and temperatures higher than the
critical point form a supercritical phase. According to an exemplary
embodiment, the dense phase is the supercritical phase. However, as
discussed later, the dense phase may include points that form a subset of
the points of the supercritical phase. The fluid in the gas phase leaving the
compressor part 12 and having the highest pressure (in the compressor) is
achieved at point 36 in Figure 3 and this fluid is then provided to an inlet 60-
1 of the pump part 14. It is noted that the pump part is designed to work
with a fluid in the dense or liquid phase and not in the gas phase and thus, the
fluid in the gas phase from the compressor part 12 has to be further processed
to reach the dense or liquid phase.
The process of transforming the fluid from the gas phase to the dense phase
is a function of the speed of each compressor stage, the temperature and
pressure of the fluid at each stage and of the coordination of the
temperatures and pressures of the fluid relative to the dome 50. Figure 3
shows how a temperature after each compressor stage may be adjusted
(lowered) for the next compressor stage to increase the efficiency of the
compressor while reducing the amount of compressor work needed
and also how the temperature of the fluid in the gas phase at the overall
outlet of the compressor part 12 is cooled to an appropriate temperature to
change its phase for the inlet of the pump part 14. According to an exemplary
embodiment, the phase transition from the gas phase to the dense phase
takes place along leg 54, e.g., at cooling device 40-6, between the
compressor part 12 and the pump part 14. In one application, a temperature
of the fluid is changed such that an enthalpy of the fluid that is provided to the
pump part is smaller than the enthalpy at the critical point 52, as shown in
Figure 3 . Figure 3 shows a constant-density line 55 corresponding to a
predetermined density for the C02 fluid. As discussed above, the
compressed fluid in the gas phase needs to cross curve 55 for entering the
dense phase. As an example, for a purity of C02 equal to or larger than 95%,
the predetermined density curve 55 is characterized by a constant density in the
range of 400 to 800 kg/m3. The predetermined density may change
depending on the application, the characteristics of the pump, the
type of fluid, the impurity of the fluid, the environment, etc. According
to an exemplary embodiment, the dense phase includes only those points
present in the supercritical phase that have the density larger than the
predetermined density.
Figure 2 shows that the temperature cooling device 40-6 may be inserted
between the last stage of the compressor part 12 and the first stage of the
pump part 14 to control a temperature of the fluid while changing from the
gas phase to the dense phase. This feature allows the operator of the
pump part to fine tune that temperature as the pump inlet pressure depends
on the fluid inlet temperature for a given pressure and also the pump inlet
pressure determines the required power to drive the pump. While the pressure
of the fluid to be provided to the pump part is controlled by the compressor
part 12, the temperature of the fluid to be provided to the pump part is
controlled by the cooling device 40-6.
Further, Figure 2 schematically shows that the stages of the compressor part
may
be paired, e.g., 1st stage paired with the 2"d stage to have a single shaft 24-1
that is rotated by a corresponding pinion that is in contact with the bull
gear 20. Furthermore, Figure 2 shows that the bull gear 20 may transfer
rotational motion to all the pinions of the compressor part 12 and to all stages
of the pump part 14. In addition, Figure 2 shows that one drive 59 drives the
bull gear 20 and the drive 59 may be placed outside the casing that houses
the compressor part. Figure 2 also shows that the pump part 14 is driven by
the same bull gear 20. According to an exemplary embodiment, the
connections among the stages of the compressor part and the pump part to the
bull gear 20 are illustrated in Figure 4, which is a schematic view of system
10. Figure 4 shows the compressor part 12 having six stages 30- 1 to 30-6,
each connected to the bull gear 20 and the pump part 14 having a single shaft
23 connected to the bull gear 20. Figure 5 illustrates piping connections
among the compressor pump stages and the pump part from a side opposite to
the driver 59. The reference numbers from Figure 1 are used n Figures 4
and 5 for the same elements, and thus, a description of these elements is not
repeated herein. Driver 59 may be an electric motor, a gas turbine, a turbo
machinery, etc. According to an exemplary embodiment, only one driver is
used to drive both the compressor part and the pump part. In another
exemplary embodiment, the driver may be provided outside a casing that
accommodates the compressor part and the pump part or inside that casing.
The pump part 14 may be implemented, according to an exemplary
embodiment shown in Figure 6, to have ten stages. More or less stages may
be implemented depending on the application. The first stage has an inlet
60-1 that receives the fluid in the dense phase and an outlet (not labeled) that
discharges the fluid to the second stage. The inlet of the second stage
receives the fluid from the first stage and the second stage discharges the fluid
to the next stage until the fluid arrives at the overall outlet 36 of the tenth
stage, which is also the overall outlet of the pump part 14. It is noted that
according to an exemplary embodiment, the pump part impellers are
connected to the same shaft 23 and thus, they rotate with a same speed.
The speed of the pump part impellers relative to the speed of the bull gear 20
is determined by the size of a connecting pinion 25. According to other
exemplary embodiments, the pump has at least eight stages. In addition,
the pump part may include other devices, e.g., cooling devices for
reducing a temperature of the fluid in the dense phase. The pump part is
housed in a pump casing 64. The pump casing 64 may be attached
(bolted) to or may be made integrally with the compressor casing 16. The
gear box 18 may be placed in the compressor casing 16. in the pump casing
64, between the two casings, or in both casings.
By having the compressor part and the pump part integrated in the same
system and/or the same skid and also having a single bull gear that drives
the various stages of the compressor and the pump, one or more
embodiments may have the advantage that the system operator does
not need to custom order the compressor and pump to match the output
of the compressor to the input of the pump for having a smooth transition
of the fluid in the gas phase from the compressor to the fluid in the dense
or liquid phase at the pump. In other words, by having a single manufacturer
of both the compressor part and the pump part that match the performance
of the compressor and the pump so as to efficiently handle a specific fluid,
for example, 002, the operator of the system is relieved of the problem of
correctly matching a compressor manufactured by a first provider to a pump
manufactured by a second provider for a specific fluid.
Other advantages of one or more embodiments are related to the reduced
power used by the integrated compressor and pump parts, the simplicity of
the driving mechanism, the reduction in components (e.g., one drive instead
of two drives), the improved synchronization of the compressor part with the
pump part as both parts are driven by the same gear, the reduced footprint of
the integrated system, and the reduced maintenance time and cost as both
parts are serviced by the same manufacturer.
According to an exemplary embodiment, the temperature control of the
fluid at different stages in the compressor part and/or the pump part may be
achieved by a processor incorporated in a control device. As shown for
example in Figure 7, the control unit 70 includes at least a processor 72 and
the control unit is connected to various sensors 74 provided in the system 10.
The connection may be wireless, as shown in Figure 7, hard wired, or a
combination thereof. The sensors 74 may include temperature sensors,
pressure sensors, speed sensors for the bull gear, and other sensors that
are known to be used in the art for monitoring the compressor part and
the pump part. The control unit 70 may be programmed with software
instructions or may be implemented in hardware to monitor the pressures
and temperatures of the compressor and pump stages and to control the
cooling devices to cool the fluid to a desired temperature. According to an
exemplary embodiment, a look-up table or a graph as shown in Figure 3 may
be stored in a memory 76 that is linked to processor 72 such that the processor
72 may determine at what temperature to cool the fluid based on the location
of the fluid in the system 10, the speed of the bull gear, and/or the pressure of
the fluid. In addition, the processor 72 may control the system 10 such that
the fluid in the compressor part and in the pump part does not reach the
area under dome 50 indicated in Figure 3 . Also, the processor 72 may be
configured to change the phase of the fluid prior to entering the pump part.
According to an exemplary embodiment illustrated in Figure 8, there is a
method for compressing a fluid in a gas phase and for pumping the fluid in a
dense phase with a system including a compressor part and a pump part, the
compressor part having at least one compressor part impeller and the pump
part having at least one pump part impeller. The method includes a step
800 of receiving at a compressor part inlet of the compressor part the fluid in
the gas phase, a step 802 of pushing the fluid in the gas phase through
one or more stages of the compressor part such that the fluid emerges at
a compressor part outlet of the compressor part as a fluid in the gas phase at
an increased density, a step 804 of transforming a phase of the fluid to the
dense phase, a step 806 of receiving the fluid in the dense phase at a pump
part inlet of the pump part, a step 808 of driving the fluid in the dense phase
through one or more stages of the pump part such that the fluid emerges
at a pump part outlet of the pump part having a higher pressure than at the
pump part inlet, and a step 810 of rotating a single bull gear in order to
activate all of the at least one or more compressor stages and the at least one
or more pump stages. The dense phase is defined by the fluid having a
density larger than the increased density.
The disclosed exemplary embodiments provide a system and a method
for compressing a fluid in a gas phase and transporting the fluid in a dense
or liquid phase. It should be understood that this description is not intended
to limit the invention. On the contrary, the exemplary embodiments are
intended to cover alternatives, modifications and equivalents, which are
included in the spirit and scope of the invention as defined by the appended
claims. Further, in the detailed description of the exemplary embodiments,
numerous specific details are set forth in order to provide a comprehensive
understanding of the claimed invention. However, one skilled in the art
would understand that various embodiments may be practiced without such
specific details.
Although the features and elements of the present exemplary embodiments
are described in the embodiments in particular combinations, each feature or
element can be used alone without the other features and elements of the
embodiments or in various combinations with or without other features and
elements disclosed herein. This written description uses examples of the subject
matter disclosed to enable any person skilled in the art to practice the same,
including making and using any devices or systems and performing any
incorporated methods. The patentable scope of the subject matter is defined
by the claims, and may include other examples that occur to those skilled in the
art. Such other examples are intended to be within the scope of the claims.
CLAIMS:
1. A system configured to compress a fluid in a gas phase and to pump the fluid
in a dense phase, the system comprising:
a compressor part having at least one impeller configured to compress the fluid
in the gas phase;
a compressor part inlet connected to the compressor part and configured
to receive the fluid in the gas phase and to provide the fluid to the at least
one impeller;
a compressor part outlet configured to provide the fluid in the gas phase at
a density equal to or larger than a predetermined density;
a temperature changing device connected to the compressor part outlet
and configured to change the fluid to the dense phase;
a pump part having at least one impeller configured to pump the fluid in the
dense phase;
a pump part inlet configured to receive the fluid in the dense phase from
the compressor part outlet;
a pump part outlet configured to output the fluid in the dense phase from
the system;
a single bull gear configured to rotate around an axial axis with a
predetermined speed;
plural pinions contacting the single gear bull and configured to rotate
with predetermined speeds, different from each other, each pinion being
configured to activate a corresponding compressor part impeller; and
a pump shaft extending from the pump part and configured to engage the
single bull gear to rotate the at least one impeller of the pump part, wherein the
at least one impeller of the compressor part has a different speed than the at
least one impeller of the pump part, and
the dense phase is defined by the fluid having a density larger than
the predetermined density.
2. The system of Claim 1, wherein the temperature changing device is one of
a cooling device, a chiller, or an expander and is provided between the
compressor part outlet and the pump part inlet, the fluid is C02, the
compressor part is configured to receive the C02 in the gas phase and to drive
out the C02 in the gas phase, and the pump part is configured to receive the
C02 in the dense phase and to drive out the C02 in the dense phase.
3. The system of Claim 1 or Claim 2, wherein the temperature changing
device is configured to reduce an enthalpy of the fluid in the gas phase to be
equal to or lower than an enthalpy of a critical point of the fluid.
4. The system of any preceding Claim, further comprising:
a single drive mechanism that drives the bull gear.
5 . The system of any preceding Claim, further comprising:
a compressor casing configured to house the compressor part and the bull
gear;
and
a pump casing configured to receive the pump part,
wherein the pump casing is attached to the compressor casing.
6 . The system of any preceding Claim, wherein the system is configured to
handle only one fluid with a predetermined efficiency and the system
cannot be reconfigured to handle another fluid with the same efficiency.
7 . The system of any preceding Claim, wherein the at least o e impeller of the
compressor part and the at least one impeller of the pump part comprise:
first to sixth compressor impellers configured such that the first and
second compressor impellers are driven at a same first speed, the third
and fourth compressor impellers are driven at a same second speed and the
fifth and sixth compressor impellers are driven at a same third speed, the
first, second and third speeds being different from each other and from the
speed of the bull gear; and first to ten pump impellers configured to be driven
at a same fourth speed by the pump shaft.
8. The system of any preceding Claim, further comprising:
N compressor impellers and M pump impellers;
piping connecting outputs and inputs of the N compressor impellers such that
the input fluid in the gas phase is driven serially through all N compressor
impellers; piping connecting an output of the Nth compressor impeller to
the M pump impellers such that the fluid in the gas phase from the Nth
compressor impeller is driven serially trough all M pump impellers after
undergoing a phase change; water removing devices provided between an
output of a compressor or a pump impeller and an input of a next compressor
or pump impeller; and at least one temperature changing device along the
piping configured to reduce a temperature of the fluid in the gas or
dense phase prior to entering a next compressor or pump impeller,
wherein N is larger than two and M is equal to or larger than one.
9 . The system of any preceding Claim, wherein there are six compressor
impellers and eight pump impellers and an input pressure at the compressor
part of a C02 in the gas phase is 1 bar and an output pressure at the pump
part of the C02 in the dense phase is between 10 and 1 0 bar.
10. A method for compressing a fluid in a gas phase and for pumping the fluid
in a dense phase with a system including a compressor part and a pump
part, the compressor part having at least one compressor part impeller and
the pump part having at least one pump part impeller, the method comprising:
receiving at a compressor part inlet of the compressor part the fluid in the
gas phase;
compressing the fluid in the gas phase in one or more stages of the
compressor part such that the fluid emerges at a compressor part outlet of the
compressor part as a fluid in the gas phase at a density equal to or larger
than a predetermined density;
transforming a phase of the fluid to the dense phase by cooling the fluid
after exiting the compressor part;
receiving the fluid in the dense phase at a pump part inlet of the pump part;
pumping the fluid in the dense phase through one or more stages of the pump
part such that the fluid emerges at a pump part outlet of the pump part having
a higher pressure than at the pump part inlet; and
rotating a single bull gear in order to activate all of the at least one or
more compressor stages and the at least one or more pump stages, wherein
the dense phase is defined by the fluid having a density larger than
the predetermined density.