Performance monitoring of pump-valve system
A pumping energy savings estimator is provided which, based on valve opening data collected for a control valve of a pump-valve system operating in an industrial process, determines an actual maximum (Δp org , ˜50% open) of valve operating region of the control valve of the pump-valve system. User can select a new maximum (Δp new , ˜70% open) of valve operating region for the control valve. Then the estimator, based on the determined actual maximum of valve operating region and the selected new maximum of valve operating region, energy saving potential (Δp save ) in the pump-valve system. The potential energy savings may be put into practice by replacing the original pump with a new smaller pump, or more preferably, replacing or processing the impeller of the original pump, such that the control valve will operate with the selected new optimal maximum opening of valve operating region.
1. A method for diagnosing a pump-valve system, comprising:
operating a control valve operating in a pump-valve system, the pump-valve system comprising a process pipeline, a pump arranged to produce a pumping pressure to provide a material flow in the pipeline, and the control valve located in the pipeline downwards from the pump to control the material flow in the pipeline;
controlling the control valve by a digital valve positioner with a first installed operating region of the valve having a first installed maximum;
collecting, by the digital valve positioner, valve opening data values of the control valve during the operation, a differential pressure across the control valve being inversely proportional to opening of the control valve in accordance to an inherent valve flow coefficient characteristic curve stored in a memory of the digital valve positioner;
providing, by the digital valve positioner, a valve opening distribution of the collected valve opening data values among a plurality of subranges of a valve operating region of the control valve;
determining, by the digital valve positioner, based on the valve opening distribution of the collected valve opening data without using flow rate or pressure measurement in the determination, an actual maximum opening of valve operating region of the control valve of the pump-valve system, the actual maximum opening being inversely proportional to a first differential pressure across the control valve and thereby to a first pumping power of the pump;
sending the valve opening distribution and the actual maximum opening of the valve operation region over a communication bus;
receiving the valve opening distribution and the actual maximum opening of the valve operation region by a valve-pump system performance estimator apparatus having a data processing unit and a graphical user interface;
displaying, by the valve-pump system performance estimator apparatus, the valve opening distribution and the actual maximum opening of the valve operation region to a user via the graphical user interface;
setting, by the valve-pump system performance estimator apparatus, a new maximum opening of valve operating region for the control valve, the new maximum opening being inversely proportional to a second differential pressure across the control valve and thereby a second pumping power of the pump;
calculating, by the valve-pump system performance estimator apparatus, based on the actual maximum opening of valve operating region and the new maximum opening of valve operating region, an estimate value which approximates a ratio of the second differential pressure to the first differential pressure across the control valve and thereby a ratio of the second pumping power to the first pumping power so that the estimate value estimates a relative reduction in the pumping power and an available energy saving potential in the pump-valve system, if the new maximum opening was configured for the control valve, without needing flow rate or pressure measurement in the estimation; and
displaying, by the valve-pump system performance estimator apparatus, the estimate value to the user via the graphical user interface.
2. A system, comprising
a process control system;
a process controlled by the process control system;
a plurality of pump-valve systems installed in the process, each pump-valve system comprising:
a process pipeline;
a pump arranged to produce a pumping pressure to provide a material flow in the pipeline; and
a control valve assembly located in the pipeline downwards from the pump to control the material flow in the pipeline, wherein the control valve assembly comprises:
a control valve;
a valve actuator; and
a digital valve positioner configured to:
control a valve opening of the control valve with the valve actuator;
collect valve opening data values during an operation of the pump-valve system over a period of time, a differential pressure across the control valve being inversely proportional to opening of the control valve in accordance to an inherent valve flow coefficient characteristic curve stored in a memory of the digital valve positioner;
provide a valve opening distribution of the collected valve opening data values among a plurality of subranges of a valve operating range and send the a valve opening distribution over a process field bus; and
determine an actual maximum opening of the control valve as a valve opening data value below which the valve opening distribution contains a predetermined portion of the collected valve opening data values, the actual maximum opening being inversely proportional to a first differential pressure across the control valve and thereby to a first pumping power of the pump, and to optionally send the actual maximum opening over a process field bus; and
a valve-pump system performance estimator apparatus having a data processing unit and a graphical user interface, the valve-pump system performance estimator apparatus being configured to:
receive the valve opening distribution;
receive or determine the actual maximum opening of the valve operation region;
display the valve opening distribution and the actual maximum opening of the valve operation region to a user via the graphical user interface;
set a new maximum opening of valve operating region for the control valve, the new maximum opening being inversely proportional to a second differential pressure across the control valve and thereby a second pumping power of the pump;
calculate, based on the actual maximum opening of valve operating region and the new maximum opening of valve operating region, an estimate value which approximates a ratio of the second differential pressure to the first differential pressure across the control valve and thereby a ratio of the second pumping power to the first pumping power so that the estimate value estimates a relative reduction in the pumping power and an available energy saving potential in the pump-valve system, if the new maximum opening was configured for the control valve, without needing flow rate or pressure measurement in the estimation; and
display the estimate value to the user via the graphical user interface.
3. The system as claimed in claim 2 , wherein the valve-pump system performance estimator apparatus is configured to set a new maximum opening of valve operating region for the control valve based on a user input via the graphical user interface.
4. A pump-valve system, comprising:
a process pipeline;
a pump arranged to produce a pumping pressure to provide a material flow in the pipeline; and
a control valve assembly located in the pipeline downwards from the pump to control the material flow in the pipeline, the control valve assembly further comprising:
a control valve;
a valve actuator; and
a digital valve positioner configured to:
control a valve opening of the control valve with the valve actuator;
collect valve opening data values during an operation of the pump-valve system over a period of time, a differential pressure across the control valve being inversely proportional to opening of the control valve in accordance to an inherent valve flow coefficient characteristic curve stored in a memory of the digital valve positioner; and
provide a valve opening distribution of the collected valve opening data values among a plurality of subranges of a valve operating range and send the a valve opening distribution over a process field bus.
5. A method for diagnosing a pump-valve system, comprising:
operating a control valve operating in a pump-valve system, the pump-valve system comprising a process pipeline, a pump arranged to produce a pumping pressure to provide a material flow in the pipeline, and the control valve located in the pipeline downwards from the pump to control the material flow in the pipeline;
transmitting, by a controller in a process control system, a control signal to the control valve over a communication bus, the control signal controlling a valve opening of the control valve within a first installed operating region of the control valve having a first installed maximum;
collecting, by a valve-pump system performance estimator apparatus having a data processing unit and a graphical user interface, indirectly based on the control signal, valve opening data values of the control valve during the operation, a differential pressure across the control valve being inversely proportional to opening of the control valve in accordance to an inherent valve flow coefficient characteristic curve;
determining, by the valve-pump system performance estimator apparatus, based on the collected valve opening data without using flow rate or pressure measurement in the determination, an actual maximum opening of valve operating region of the control valve of the pump-valve system, the actual maximum opening being inversely proportional to a first differential pressure across the control valve and thereby to a first pumping power of the pump;
setting, by the valve-pump system performance estimator apparatus, a new maximum opening of valve operating region for the control valve, the new maximum opening being inversely proportional to a second differential pressure across the control valve and thereby a second pumping power of the pump;
calculating, by the valve-pump system performance estimator apparatus, based on the actual maximum opening of valve operating region and the new maximum opening of valve operating region, an estimate value which approximates a ratio of the second differential pressure to the first differential pressure across the control valve and thereby a ratio of the second pumping power to the first pumping power so that the estimate value estimates a relative reduction in the pumping power and an available energy saving potential in the pump-valve system, if the new maximum opening was configured for the control valve, without needing flow rate or pressure measurement in the estimation; and
displaying, by the valve-pump system performance estimator apparatus, the estimate value to a user via the graphical user interface.
6. The method as claimed in claim 5 , wherein the step of setting comprises displaying, by the valve-pump system performance estimator apparatus, the actual maximum opening of valve operating region to the user via the graphical user interface.
7. The method as claimed in claim 5 , wherein the step of setting comprises setting, by the valve-pump system performance estimator apparatus, the new maximum opening of valve operating region for the control valve based on a user input via the graphical user interface.
8. A valve-pump system performance estimator apparatus, comprising:
a data processing unit; and
a graphical user interface,
wherein the valve-pump system performance estimator apparatus is configured to communicate with a process control system which controls a pump-valve system including a process pipeline, a pump arranged to produce a pumping pressure to provide a material flow in the pipeline, and a control valve located in the pipeline downwards from the pump to control the material flow in the pipeline, the process control system transmitting a control signal to the control valve over a communication bus, the control signal controlling a valve opening of the control valve within a first installed operating region of the control valve having a first installed maximum,
valve-pump system performance estimator apparatus is configured to collect, indirectly based on the control signal, valve opening data values of the control valve during the operation, a differential pressure across the control valve being inversely proportional to opening of the control valve in accordance to an inherent valve flow coefficient characteristic curve,
valve-pump system performance estimator apparatus is configured to determine, based on the collected valve opening data without using flow rate or pressure measurement in the determination, an actual maximum opening of valve operating region of the control valve of the pump-valve system, the actual maximum opening being inversely proportional to a first differential pressure across the control valve and thereby to a first pumping power of the pump,
wherein valve-pump system performance estimator apparatus is configured to set a new maximum opening of valve operating region for the control valve, the new maximum opening being inversely proportional to a second differential pressure across the control valve and thereby a second pumping power of the pump,
valve-pump system performance estimator apparatus is configured to calculate, based on the actual maximum opening of valve operating region and the new maximum opening of valve operating region, an estimate value which approximates a ratio of the second differential pressure to the first differential pressure across the control valve and thereby a ratio of the second pumping power to the first pumping power so that the estimate value estimates a relative reduction in the pumping power and an available energy saving potential in the pump-valve system, if the new maximum opening was configured for the control valve, without needing flow rate or pressure measurement in the estimation, and
valve-pump system performance estimator apparatus is configured to display, the estimate value to a user via the graphical user interface.
9. The valve-pump system performance estimator apparatus as claimed in claim 8 , wherein the valve-pump system performance estimator apparatus is configured to set the new maximum opening of valve operating region for the control valve based on a user input via the graphical user interface.
10. The valve-pump system performance estimator apparatus as claimed in claim 8 , wherein the valve-pump system performance estimator apparatus is configured to display the actual maximum opening of valve operating region to the user via the graphical user interface.
11. The method according to claim 1 , comprising the calculating of the estimate value is additionally based on a ratio of a static head to a total pumping pressure of the pump-valve system, and optionally additionally based on a ratio of dynamic piping pressure losses to the total pumping pressure.
12. The method according to claim 1 , wherein said calculating of the estimate value estimating the energy saving potential of the pump-valve system comprises determining the savings potential by the following equation or an approximation thereof
P
new
P
org
=
Δ
p
new
+
Δ
p
p
+
Δ
p
sh
Δ
p
org
+
Δ
p
p
+
Δ
p
sh
wherein
Δporg=original differential pressure across the control valve
Δpnew=new differential pressure across the control valve
Δpp=pressure loss due to a flow resistance of piping
Δpsh=static pressure head.
13. The method according to claim 1 , wherein said determining of the energy saving potential of the pump-valve system comprises determining the savings potential as
P
new
P
org
=
(
1
-
h
org
2
)
(
h
org
h
new
)
2
n
+
h
org
2
+
x
sh
1
+
x
sh
wherein
Pnew=new pumping power
Porg=original pumping power
n=2 represents an equal-percentage characteristic curve of the control valve
n=1 represents a linear characteristic curve of the control valve,
n=0.5 represents a quickly opening control valve
hnew=new maximum of valve operating region of the valve
horg=original maximum of valve operating region of the valve
xsh=a ratio of a static head to a total pumping pressure.
14. The method according to claim 1 , wherein said calculation of the estimate value that estimates a relative reduction in the pumping power and the available energy saving potential of the pump-valve system comprises calculating estimate value by the following equation or an approximation thereof
P
new
P
org
=
(
1
-
h
org
2
)
e
-
2
ln
(
1
/
ϕ
0
)
*
(
h
new
-
h
org
)
+
x
p
(
h
org
h
pl
)
2
+
x
sh
(
1
-
h
org
2
)
+
x
p
(
h
org
h
pl
)
2
+
x
sh
wherein
hnew=new maximum of valve operating region of the control valve
horg=original maximum of valve operating region of the control valve
hpl=a planning point opening
xsh=a ratio of a static head to a total pumping pressure
xp=a ratio of a piping pressure loss to a total pumping pressure
ϕ0=constant
Pnew=new pumping power
Porg=original pumping power.
15. The method according to claim 1 , wherein said calculation of the estimate value that estimates a relative reduction in the pumping power and the available energy saving potential of the pump-valve system comprises calculating the estimate value by the following equation or an approximation thereof
P
new
P
org
=
(
1
-
h
org
2
)
h
org
4
h
new
4
+
x
p
h
pl
2
+
x
sh
(
1
-
h
org
2
)
+
x
p
h
pl
2
+
x
sh
wherein
hnew=new maximum of valve operating region of the control valve
horg=original maximum of valve operating region of the control valve
hpl=a planning point opening
xsh=a ratio of a static head to a total pumping pressure
xp=a ratio of a piping pressure loss to a total pumping pressure
Pnew=new pumping power
Porg=original pumping power.