U.S. patent application number 14/163785 was filed with the patent office on 2015-07-30 for pump system with flow control.
This patent application is currently assigned to Caterpillar Inc.. The applicant listed for this patent is Caterpillar Inc.. Invention is credited to Alex P. Brinkman, Trevor N. Iund, Benjamin Minteer, Don M. Wilbur, JR..
Application Number | 20150211529 14/163785 |
Document ID | / |
Family ID | 53678615 |
Filed Date | 2015-07-30 |
United States Patent
Application |
20150211529 |
Kind Code |
A1 |
Minteer; Benjamin ; et
al. |
July 30, 2015 |
Pump System with Flow Control
Abstract
A pump system is provided including a power source, a pump and a
transmission. First and second sensors are configured to
respectively provide information indicative of at least one actual
first operating condition relating to the pump and to information
indicative at least one operating condition relating to the
transmission. A controller is configured to adjust the power source
or the transmission based on an output flow rate of the pump. The
controller is configured to perform a first comparison of the first
operating condition and a predetermined first operating condition
and a second comparison of the second operating condition to a
predetermined second operating condition and based on the first and
second comparisons determine if the controller should continue to
adjust the power source or the transmission based on the output
flow rate of the pump.
Inventors: |
Minteer; Benjamin; (Hanna
City, IL) ; Brinkman; Alex P.; (Mt. Zion, IL)
; Wilbur, JR.; Don M.; (Manito, IL) ; Iund; Trevor
N.; (Peoria, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Caterpillar Inc. |
Peoria |
IL |
US |
|
|
Assignee: |
Caterpillar Inc.
Peoria
IL
|
Family ID: |
53678615 |
Appl. No.: |
14/163785 |
Filed: |
January 24, 2014 |
Current U.S.
Class: |
417/15 |
Current CPC
Class: |
F04D 7/04 20130101; F04D
15/0066 20130101 |
International
Class: |
F04D 15/00 20060101
F04D015/00; F04D 7/00 20060101 F04D007/00 |
Claims
1. A pump system, comprising: a power source; a pump; a
transmission configured to operatively connect an output rotation
of the power source to an input rotation of the pump; a first
sensor configured to provide information indicative of at least one
actual first operating condition relating to the pump; a second
sensor configured to provide information indicative at least one
operating condition relating to the transmission; and a controller
in communication with the first sensor and the second sensor, the
controller being configured to adjust the power source or the
transmission based on an output flow rate of the pump, the
controller being configured to perform a first comparison of the
first operating condition and a predetermined first operating
condition and a second comparison of the second operating condition
to a predetermined second operating condition and based on the
first and second comparisons determine if the controller should
continue to adjust the power source or the transmission based on
the output flow rate of the pump.
2. The pump system according to claim 1 wherein the first operating
condition comprises a pump flow rate.
3. The pump system according to claim 1 wherein the first operating
condition comprises a pump discharge pressure.
4. The pump system according to claim 1 wherein the second
operating condition is a transmission output speed.
5. The pump system according to claim 1 wherein the second
operating condition is a transmission input speed.
6. The pump system according to claim 1 wherein the transmission
includes a torque converter fluidly connecting an output of the
engine to an input of a gear box, the gear box being mechanically
connected to an input of the pump and having a plurality of gear
combinations.
7. The pump system according to claim 6 wherein the wherein the
second operating condition is a torque converter output speed.
8. A method of controlling a pump system having a power source, a
pump and a transmission configured to operatively connect an output
rotation of the power source to an input rotation of the pump, the
method comprising: selectively adjusting the power source or the
transmission based on an output flow of the pump; sensing a first
parameter indicative of at least one first operating condition
relating to the pump; sensing a second parameter indicative of at
least one second operating condition relating to the transmission;
performing a first comparison of the first actual operating
condition and a predetermined first operating condition; performing
a second comparison of the second actual operating condition and a
predetermined second operating condition; and determining based on
the first and second comparisons if the power source or the
transmission should continue to be adjusted based on the output
flow of the pump.
9. The method according to claim 9 wherein the first operating
condition comprises a pump flow rate.
10. The method according to claim 9 wherein the first operating
condition comprises a pump discharge pressure.
11. The method according to claim 9 wherein the second operating
condition is a transmission output speed.
12. The method according to claim 9 wherein the second operating
condition is a transmission input speed.
13. The method according to claim 9 wherein the transmission
includes a torque converter fluidly and a gear box and wherein the
second operating condition is a torque converter output speed.
14. A pump system, comprising: an engine; a slurry pump; a
transmission configured to operatively connect an output rotation
of the power source to an input rotation of the pump, the
transmission including a torque converter fluidly connecting an
output of the engine to an input of a gear box, the gear box being
mechanically connected to an input of the slurry pump and having a
plurality of gear combinations; a first sensor configured to
provide information indicative of at least one first actual
operating condition relating to the slurry pump; a second sensor
configured to provide information indicative of at least one actual
operating condition relating to the transmission; and a controller
in communication with the first sensor and the second sensor, the
controller being configured to adjust the engine or the
transmission based on an output flow rate of the slurry pump, the
controller being configured to perform a first comparison of the
first operating condition and a predetermined first operating
condition and a second comparison of the second operating condition
to a predetermined second operating condition and based on the
first and second comparisons determine if the controller should
continue to adjust the engine or the transmission based on the
output flow rate of the slurry pump.
15. The pump system according to claim 1 wherein the first
operating condition comprises a pump flow rate.
16. The pump system according to claim 1 wherein the first
operating condition comprises a pump discharge pressure.
17. The pump system according to claim 1 wherein the second
operating condition is a transmission output speed.
18. The pump system according to claim 1 wherein the second
operating condition is a transmission output speed.
19. The pump system according to claim 1 wherein the second
operating condition is a transmission input speed.
20. The pump system according to claim 6 wherein the wherein the
second operating condition is a torque converter output speed.
Description
TECHNICAL FIELD
[0001] This patent disclosure relates generally to pump systems
and, more particularly, to pump systems with flow control.
BACKGROUND
[0002] A slurry pump is a type of pump that increases the pressure
of a liquid/solid particulate mixture. Slurry pumps are widely used
to transport raw minerals and ore (e.g., coal, sand, oil, etc.),
waste material (e.g., sewage), and refined products. One
application for such slurry pumps is oil or gas well cementing
systems. Part of the process of preparing an oil or natural gas
well for further drilling, production or abandonment involves
pumping cement into place in a wellbore. Well cementing systems
typically use a power source (e.g., an engine or electric motor)
connected through a transmission to a fixed displacement pump. The
transmission provides a direct mechanical connection from the power
source to the pump. In these configurations, the power source is
typically operated at a constant speed to provide a single flow
rate of cement from the pump for each available gear ratio.
[0003] One problem with a conventional slurry pump system involves
flow rate consistency. In particular, as a load on the pump changes
due to changing conditions at an associated well or mine (e.g., due
to a density change or plugged hose), the flow rate of slurry from
the pump will likewise fluctuate. Typically, the operator manually
adjusts the engine governor and transmission control settings to
achieve and maintain the desired pump flow and pressure. Given the
variability associated with well cement and the well cementing
process, it is very difficult for the operator to manually control
cement flow and pressure throughout the entire cementing
process.
[0004] An attempt to address fluctuations in pump flow rate is
described in U.S. Pat. No. 6,033,187 that issued to Addie on Mar.
7, 2000 ("the '187 patent"). Specifically, the '187 patent
discloses a way to determine an instantaneous pressure produced by
a slurry pump. Using this pressure, along with an overall total
pipeline resistance, an optimal operating speed of the pump may
then be determined. This speed may then be controlled, for example
by changing the output ratio of the gear box (if available), to
improve stability of the pumping system.
[0005] Although the system of the '187 patent may be adequate for
some applications, it may also suffer from drawbacks. In
particular, it may be difficult and time consuming (or not even
possible) to change the output ratio of the gear box. In addition,
this change may only provide step-wise adjustment in pump speed,
which may lack fine control necessary for some operations. Further,
the gear box required to provide the desired ratio(s) may be large,
heavy, and expensive.
SUMMARY
[0006] In one aspect, the disclosure describes a pump system
including a power source, a pump and a transmission configured to
operatively connect an output rotation of the power source to an
input rotation of the pump. A first sensor is configured to provide
information indicative of at least one actual first operating
condition relating to the pump. A second sensor is configured to
provide information indicative at least one operating condition
relating to the transmission. A controller is in communication with
the first sensor and the second sensor. The controller is
configured to the power source or the transmission based on an
output flow rate of the pump. The controller is configured to
perform a first comparison of the first operating condition and a
predetermined first operating condition and a second comparison of
the second operating condition to a predetermined second operating
condition and based on the first and second comparison determine if
the controller should continue to adjust the power source or the
transmission based on the output flow rate of the pump.
[0007] In another aspect, the disclosure describes a method of
controlling a pump system having a power source, a pump and a
transmission configured to operatively connect an output rotation
of the power source to an input rotation of the pump. The method
includes the step of selectively adjusting the power source or the
transmission based on an output flow of the pump. A first parameter
indicative of at least one first operating condition relating to
the pump is sensed. A second parameter indicative of at least one
second operating condition relating to the transmission is sensed.
A first comparison of the first actual operating condition and a
predetermined first operating condition is performed. A second
comparison of the second actual operating condition and a
predetermined second operating condition is performed. It is
determined based on the first and second comparisons if the power
source or transmission should continue to be adjusted based on the
output flow of the pump.
[0008] In yet another aspect, the disclosure describes a pump
system including an engine, a slurry pump, and a transmission
configured to operatively connect an output rotation of the power
source to an input rotation of the pump. The transmission includes
a torque converter fluidly connecting an output of the engine to an
input of a gear box. The gear box is mechanically connected to an
input of the slurry pump and has a plurality of gear combinations.
A first sensor is configured to provide information indicative of
at least one first actual operating condition relating to the
slurry pump. A second sensor is configured to provide information
indicative of at least one actual operating condition relating to
the transmission. A controller is in communication with the first
sensor and the second sensor. The controller is configured to
adjust the engine or the transmission based on an output flow rate
of the slurry pump. The controller is configured to perform a first
comparison of the first operating condition and a predetermined
first operating condition and a second comparison of the second
operating condition to a predetermined second operating condition.
Based on the first and second comparisons, the controller
determines if the controller should continue to adjust the engine
or the transmission based on the output flow rate of the slurry
pump.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic side view of an exemplary pump system
according to the present disclosure.
[0010] FIG. 2 is a schematic diagram of a pump system operatively
connected to a well according to the present disclosure.
[0011] FIG. 3 is a flow chart illustrating one method of performing
a flow control test according to the present disclosure.
DETAILED DESCRIPTION
[0012] This disclosure generally relates to a pump system and
associated method that provides a flow control test. With
particular reference to FIG. 1, an exemplary pump system 10 is
shown. The pump system 10 may include, among other things, a power
source, such as an engine 12 operatively connected to a pump 14 by
way of a transmission 15, including in this case a torque converter
16 and a gear box 18. The engine 12 may be configured to generate a
rotational power output. The torque converter 16 may be configured
to transfer at least a portion of the power output to the gear box
18. The gear box 18 may convert the rotation received from the
torque converter 16 to a rotation having a different speed and
torque, and deliver the converted rotation as an input to drive the
pump 14. FIG. 2 is a schematic diagram showing the pump system 10,
including the engine 12, transmission 15 and pump 14, operatively
connected to a well 19 for pumping a fluid or slurry, such as
cement, into the well 19. While aspects of the present disclosure
may be described in connection with a well cementing operation, the
present disclosure is not limited to that particular application.
Rather, the present disclosure can be applied to any application in
which a fluid is pumped and is particularly applicable to slurry
pumping operations.
[0013] The engine 12 may produce a rotational output having both
speed and torque components, and may embody an internal combustion
engine. For example, the engine 12 may be a diesel engine, a
gasoline engine, a gaseous fuel-powered engine, or any other engine
apparent to one skilled in the art. The engine 12 may contain an
engine block having a plurality of cylinders (not shown),
reciprocating pistons disposed within the cylinders (not shown),
and a crankshaft operatively connected to the pistons (not shown).
The internal combustion engine may use a combustion cycle to
convert potential energy (usually in chemical form) within the
cylinders to a rotational output of the crankshaft, which may in
turn rotate an input of the transmission 15, in this instance the
torque converter 16.
[0014] The torque converter 16 may be used to transmit power from
the crankshaft of the engine 12 to the gear box 18. In one
embodiment, the torque converter 16 may be a hydro-mechanical
device that allows the crankshaft of the engine 12 to rotate
somewhat independently of an input shaft of the gear box 18. In
this embodiment, the torque converter 16 includes an impeller (not
shown) fixedly connected to the crankshaft of the engine 12, and a
turbine (not shown) fixedly connected to the input shaft of the
gear box 18. The impeller may be fluidly coupled with the turbine,
such that as the impeller rotates, a pressurized flow of fluid may
be generated and directed through the turbine, driving the turbine
to also rotate. At low fluid flow rates and pressures (or when the
pump 14 is heavily and/or suddenly loaded), the impeller may rotate
at a higher speed relative to the turbine. However, as the pressure
and the flow rate of the fluid conducted between the impeller and
the turbine increases (or when the pump 14 is lightly loaded), the
rotational speed of the turbine may approach the rotational speed
of the impeller. This may allow the engine 12 to rotate at a
different speed and torque than the gear box 18, depending on
operating conditions, with the difference in speed and torque being
accounted for by shearing losses (i.e., heat) within the fluid.
[0015] Alternatively, the torque converter 16 could be another type
of fluidic or non-fluidic coupling, if desired. For example, the
torque converter 16 could include friction plates coupled to the
crankshaft and gear box shaft. The friction plates could be
configured to slidingly and rotationally engage each other, and
thereby transfer a percentage of the power generated by the engine
12 to the gear box 18. Other configurations of the torque converter
16 may also be possible.
[0016] In some embodiments, the torque converter 16 may also
include a lockup clutch (generically represented by a box 20 in
FIG. 1) disposed in parallel with the impeller and turbine (or
friction plates, if so equipped). The lockup clutch 20 may be
configured to selectively and mechanically lock the crankshaft
directly to the gear box input shaft, such that both shafts rotate
at the same speed. The lockup clutch 20, if included, may be
activated manually or automatically, as will be described
below.
[0017] The gear box 18 may include numerous components that
interact to transmit power received from the engine 12 (via torque
converter 16) to the pump 14. In particular, the gear box 18 may
embody a mechanical transmission having one or more forward gear
ratios. In some embodiments, the gear box 18 may also include a
neutral position and/or one or more reverse gear ratios. In
embodiments where more than one gear ratio is included, the gear
box 18 may additionally include one or more clutches (not shown)
for selectively engaging predetermined combinations of gears (not
shown) that produce a desired gear ratio.
[0018] The gear box 18, if equipped with multiple gear
combinations, may be an automatic-type transmission wherein
shifting between gear ratios is based on a power source speed, a
maximum operator selected gear ratio, a load from the pump 14,
and/or a fluid pressure within gear box 18. Alternatively, the gear
box 18 may be a manual transmission, wherein the operator manually
engages the desired gear combinations. Regardless of the type of
transmission 15, the output of the gear box 18 may be connected to
rotatably drive an input shaft of the pump 14.
[0019] In one embodiment, each ratio of the gear box 18 may be
about 7:1 or less. In particular, the gear box 18 may be configured
to produce an output speed that is about the same as or up to seven
times less than an input speed received by the gear box 18. This
reduction may typically be too small to accommodate slurry pumping
applications with high accuracy. That is, transmissions typically
used in slurry pumping applications may require speed reductions of
7:1 or greater. However, when used in conjunction with the torque
converter 16 in its unlocked state (i.e., during a torque converter
drive mode), slippage between the impeller and the turbine (or
between the friction plates) combines with the ratio reduction of
the gear box 18 to produce sufficiently high speed reductions
(i.e., reductions greater than about 7:1).
[0020] The pump 14 may be a positive displacement plunger type pump
capable of generating an output flow rate of about 10-20 gallons
per minute. The pump 14 may be configured to transport a
fluid/particle mixture (e.g., oil sands, sewage, petroleum,
petrochemicals, cement, etc.). The mixture may enter the pump and
be accelerated by the plungers (not shown), causing the mixture to
flow outward through the housing. In this configuration, the
plungers may be directly driven by the output shaft of the gear box
18 at a speed that is about seven or more times slower than the
output speed of the power source 12. It is contemplated that the
pump 14 may be a different type of pump, if desired, such as a lobe
pump, centrifugal pump or a peristaltic hose pump. The pump 14 may
produce an output flow rate dependent on conditions of the
fluid/particle mixture (e.g., density, viscosity, etc.), size of
the plungers and housing, and the input rotation (i.e., speed and
torque) provided by the gear box 18.
[0021] A controller 26 may be associated with pumping system 10,
and configured to regulate the output flow rate of the pump 14. In
particular, controller 26 may be configured to receive an
indication of, and/or calculate an actual output flow rate of the
pump 14, receive from the operator an indication of a desired
output flow rate of the pump 14, and responsively adjust operation
of the engine 12 or the transmission 15 to reduce an error between
the actual and desired output flow rates. The controller 26 may be
configured to adjust the speed of the engine 12 by adjusting
fueling of the engine 12. With respect to the transmission 15, the
controller 26 may be configured to adjust the gear of the
transmission 15 and/or the state of the lock-up clutch 20 to reduce
the error between the actual and desired output flow rates.
[0022] The operator of pumping system 10 may be able to input
instructions via one or more interface devices located at a control
panel that also houses the controller 26. These instructions may
include, among other things, a desired output flow rate of the pump
14, a desired gear ratio of the gear box 18, and/or a status of the
lockup clutch 20 (e.g., engaged or disengaged). Signals indicative
of these instructions may be directed to the controller 26 for
further processing.
[0023] The controller 26 may further be configured to monitor
various operational parameters of the pump system 10. More
specifically, the controller 26 may be configured to perform a test
on the condition of the pump system 10 by receiving information
about one or more actual operational parameters of the pump system
10 and comparing that information to predefined operational
parameters. The controller 26 may further be configured to
determine from the results of that comparison whether the pump
system 10 should continue operating based on flow control.
[0024] The actual operational parameters of the pump system 10 that
may be used by the controller 26 in performing the test may include
information relating to the load on the pump 14 and the conditions
in the application in which the pump system 10 is operating, e.g.
the well 19 conditions for a well cementing application. The
operational parameters relating to the load on the pump 14 and the
well 19 condition may include, in one embodiment, the actual flow
rate of the pump 14, the system pressure and operating parameters
of the transmission 15. In one example, information regarding the
actual flow rate of the pump 14 may be communicated to the
controller 26 by a sensor 28 associated with the input shaft of the
pump 14. In this example, the sensor 28 is a speed sensor and
signals generated by the sensor 28 may be used by the controller
26, such as through information provided in the controller 26 on
the configuration of the pump 14, to calculate or otherwise
determine the actual flow rate of the pump 14. It is contemplated,
however, that the sensor 28 could otherwise be configured to
directly sense the actual flow rate and/or sense other or
additional flow rate parameters (e.g., pressure) that subsequently
may be used by the controller 26 to calculate the actual output
flow rate, if desired.
[0025] Information regarding the system pressure may be provided by
a sensor 30, for example, a pressure sensor, arranged and
configured to determining the pressure in the system at a point
downstream of the discharge of the pump 14. In one embodiment, the
pressure sensor 30 may be arranged directly at the pump 14.
Alternatively, the pressure sensor 30 may be arranged somewhere in
the discharge line connecting the pump 14 to the particular
application load, such as the well 19. If desired, the sensor 30
could otherwise be arranged and configured to sense other or
additional system parameters that subsequently may be used by the
controller 26 to calculate the actual system pressure.
[0026] The information regarding the operating parameters of the
transmission 15 that are communicated to the controller 26 may
include information about the input and output speeds of the torque
converter 16. In the schematic drawing of FIG. 2, information
relating to the input speed of the torque converter 16 is provided
by a sensor 32 (e.g., a speed sensor) arranged and configured to
determine the output speed of the engine 12. While this sensor 32
is shown schematically at the engine 12 in FIG. 2 it should be
understood that the sensor 32 could be arranged in other locations
including at the torque converter 16. The information regarding the
output speed of the torque converter 16 may be provided a sensor 34
arranged and configured to determine the output speed of the torque
converter 16. In FIG. 2, this sensor 34 is shown schematically
arranged at the transmission 15. However, it will be appreciated
that the sensor 34 may be arranged in other locations. For example,
the sensor 34 could be located at the output of the gear box 18
(such as when a torque converter is not provided) or at the input
of the pump 14. In particular, information regarding the output
speed of the torque converter 16 may be calculated by the
controller based on information from the sensor 28 arranged at the
input shaft of the pump 14.
[0027] Information regarding the load on the pump 14 may be
calculated by the controller 26 based on the information monitored
regarding the transmission operating parameters including the input
speed (e.g., the power source output speed) and output speed of the
torque converter 16. In particular, when the lockup clutch 20 is
disengaged, the controller 26 may use the information relating to
the input speed of the torque converter 16 from sensor 32 (measured
as engine speed) and the information about the output speed of the
torque converter 16 from sensor 34 to calculate the torque
converter 16 output torque using lookup tables or maps relating to
the torque converter provided in the controller. The operating
parameters of the pump system 10 relating to load on the pump 14
also may be provided or calculated by the controller 26 in other
ways. For example, a torque meter may be provided that is arranged
and configured to provide information regarding the output torque
of the transmission 15, such as at the output of the torque
converter 16 or at the output of the gear box 18.
[0028] The operational parameters of the pump system 10 relating to
the application in which the pump system 10 is being used, for
example the well 19, may include information other than the system
flow rate and pressure. For example, the operational parameters may
include information relating to the fluid or slurry being pumped.
This information could include information relating to the density
of the fluid or slurry being pumped. As will be appreciated, other
"well" related information also could be monitored and used by the
controller 26 in performing the testing used to determine whether
to discontinue the flow control. Other operational parameters of
the pump system 10 that may be monitored and compared with
predetermined values during the testing may include vibration
information (gathered, for example, by accelerometers) and
temperature information (gathered, for example, by thermocouples)
from the engine 12, transmission 15 or pump 14.
[0029] The controller 26 may embody a single processor or multiple
processors that include a means for controlling an operation of
pumping system 10. Numerous commercially available processors may
perform the functions of controller 26. The controller 26 may
include or be associated with a memory for storing data such as,
for example, an operating condition, design limits, performance
characteristics or specifications of pumping system 10, operational
instructions, and corresponding fueling parameters. This data may
be stored within the memory of controller 26 in the form of one or
more lookup tables, as desired. Alternatively or additionally, the
controller 26 may perform various calculations using data produced
by the various sensors and stored in maps. Various other known
circuits may be associated with the controller 26, including power
supply circuitry, signal-conditioning circuitry, solenoid driver
circuitry, communication circuitry, and other appropriate
circuitry. Moreover, as shown in FIG. 2, the controller 26 may be
capable of communicating with other components of pumping system 10
such as the engine 12, the transmission 15, the pump 14 and the
sensors 28, 30, 32, 34 via either wired or wireless transmission
and, as such, controller 26 may be connected to or alternatively
disposed in a location remote from power source 12 and/or pump
14.
[0030] Referring to FIG. 3 of the drawings, a schematic flow
diagram is provided that includes various steps that may be
implemented by the controller 26 to provide a test to determine if
flow control of the pump system 10 should continue. The test may be
automatically directed by the controller 26 periodically or in a
continuous cycle while the pump system is operating using flow
control. In steps 36, 38 and 40, information is collected relating
to one or more operational parameters of the pump system 10
including, for example, the actual pump load, the system flow rate
and the transmission 15 operating parameters. This information can
be collected by the various sensors provided in the pump system 10
including, for example, sensors 28, 30, 32, 34. Information
relating to the operating parameters of the pump system 10 other
than or in addition to that shown in FIG. 3 also may be collected
such as other information relating to the load on the pump 14, the
engine 12 operating condition, the transmission 15 operating
condition, the pump 14 operating condition, and the application
conditions (e.g., the well 19).
[0031] The information relating to the operational parameters of
the pump system 10 that is collected in steps 36, 38 and 40 is
processed as necessary in step 42. The resultant processed
information from step 42 is then used in step 44 to compare the
actual operational parameters with predetermined operating
parameters. In FIG. 3, the controller 26 compares the actual pump
load, flow rate and the transmission operating parameters to
predetermined values for the pump load, flow rate and transmission
operating parameters. The predetermined operating parameters, like
the predetermined operating condition, may be set by specific
guidelines, specifications or regulations that are unique to the
user of the pumping system, the particular application or a
governmental body.
[0032] In step 46, the controller 26 may determine if the actual
pump system operating parameters are within defined limits of the
predetermined parameters from step 44. The criteria for determining
whether the pump system 10 passes the test can be based on whether
one or more of the actual operating parameters exceed or fail to
reach the predetermined operating parameters as determined in step
44. If it is determined that the operating parameters are within
the defined limits in step 46, the method may proceed back to step
44 and the test cycle is repeated with updated information on the
pump load, flow rate and/or transmission parameters. If it is
determined that the pumping system has failed the test in step 46,
the method may proceed to step 48 and the controller will exit the
flow control routine, i.e. discontinue flow control of the pump
system 10. Upon discontinuing flow control, the controller may be
configured to direct the pump system into a safe operating
mode.
INDUSTRIAL APPLICABILITY
[0033] The present disclosure is applicable to any type of pump
system used in an application to generate a flow of fluid. The
disclosed pumping system may be particularly applicable to slurry
pumping applications involving relatively dense fluid/particle
mixtures. As noted previously, one exemplary application for the
pump system 10 is a cementing application. In a cementing
application, a relatively dense cement slurry is directed into a
well bore by the pump 14 during drilling of the well. This slurry
displaces drilling fluids in the bore, and forms a casing for the
bore as the drilling progresses. In order for the integrity of the
casing to be maintained, the flow rate of the slurry into the well
bore must be tightly controlled relative to the drilling
process.
[0034] To initiate operation of the pump system 10 during the
cementing process, the operator may input, via the control panel, a
desired output flow rate of the pump 14, a desired ratio of the
gear box 18, and a desired state of the lockup clutch 20. While
pumping the cement slurry into the well bore, the actual output
flow rate of pump 14 may be monitored by way of the sensor 28.
Specifically, signals generated by the sensor 28 may be directed to
the controller 26 and, based on the values of these signals, the
controller 26 may calculate or otherwise determine the actual
output flow rate of pump 14. The controller 26 may then determine
an error as a function of the actual and desired output flow rates.
For example, controller 26 may determine a difference between these
flow rates.
[0035] If the supply of cement slurry is too fast, relative to
advancement of drilling within the well bore, the excess slurry may
interfere with the drilling. Similarly, if the supply of cement
slurry is too slow, the drilling may outpace casing formation.
Accordingly, the controller 26 may be configured to reference the
difference between the actual output flow rate and the desired
output flow rate with the lookup table stored in memory to
determine if a change in the speed of the engine 12, the
transmission gear and/or the state of the lockup clutch is required
to properly support the drilling operation. A new fuel setting of
the engine 12, transmission gear or lockup clutch state may then be
determined that produces the required change in speed, and the
controller 26 may issue a command to the engine 12 to operate at
the new fuel setting.
[0036] The test performed by the controller 26 to determine if the
flow control should continue can help protect the pump system 10
from damage by, for example, directing it into a safe operating
mode when the controller determines that one or more operational
parameters are not within predetermined limits. Circumstances in
which the flow control could be discontinued due to failure of the
test performed by the controller could include a clogged cement
line or a significant increase in the density of the cement being
pumped into the well.
[0037] It will be appreciated that the foregoing description
provides examples of the disclosed system and technique. However,
it is contemplated that other implementations of the disclosure may
differ in detail from the foregoing examples. All references to the
disclosure or examples thereof are intended to reference the
particular example being discussed at that point and are not
intended to imply any limitation as to the scope of the disclosure
more generally. All language of distinction and disparagement with
respect to certain features is intended to indicate a lack of
preference for those features, but not to exclude such from the
scope of the disclosure entirely unless otherwise indicated.
[0038] Recitation of ranges of values herein are merely intended to
serve as a shorthand method of referring individually to each
separate value falling within the range, unless otherwise indicated
herein, and each separate value is incorporated into the
specification as if it were individually recited herein. All
methods described herein can be performed in any suitable order
unless otherwise indicated herein or otherwise clearly contradicted
by context.
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