Diagnostics for Reciprocating Compressors in Refineries
速
PROGNOST -NT for Refining
Intelligence on Duty The path to successful products and services is always by way of intensive dialogue with potential buyers and customers. Only by exchanging experience on a continuous basis is it possible to gain the necessary knowledge of operator requirements which fuels the development to useful products. PROGNOST Systems defines “Intelligence on Duty� using this philosophy: through the continuous integration of new requirements and practical experiences, state of the art technology is always available to users. This permanentdevelopment process leads to products and services providing exceptional benefits to our customers. The consistent adoption of this philosophy ensures that PROGNOST products and services will continue to meet the ever increasing expectations of our customers in the future.
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Typical PROGNOST速-NT Sensor Positions Example: 4-throw process compressor
1 Trigger switch 4 Acceleration vibration sensors at crosshead 4 Vertical rod position sensors 8 indicated pressure probes for p-V diagrams DCS values e.g. temperatures (bearing, valves), line pressures 4 Acceleration vibration sensors at cylinders
Typical PROGNOST速-NT Sensor Signals p-V diagram: the coloured areas show the suction loss (bottom) and discharge loss (top). This diagram also shows the polytropic exponents (expansion/ compression) which help to automatically detect 1500 p si a
leakages of sealing components such as valves, packings, piston sealing rings in early stages. Further, this measurement shows any problems with active valve control systems.
T DC
BD
1400
2
1300
1
1200 1100
compression
expansion
1000 900 800
1
2 700 600 0 ,0
0 ,5
1 ,0
1 ,5
2 ,0
2 ,5 3 ,0 3 ,5 P i sto n vo l u m e [g a l ]
4 ,0
4 ,5
5 ,0
5 ,5
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Condition Monitoring System Early Failure Detection (Correlation of machine functions to crank angle) 128 m/s²
TDC
BDC
TDC
TDC = discharge valve closes
105
90
75
45° after TDC = suction valve opens
60
45
30
15
BDC = suction valve closes 0
45° -15
-30
-45
240° after TDC = discharge valve opens -60
-75
-90
-105 -120
0
20
40
Machine LM9 C1-5 LM9 C1-5 LM9 C1-5
60
80
100
Measuring Point V 2nd ST Cyl 1 P 2nd ST HE 1 P 2nd ST CE 1
120
140
160
Data name Vibration signal Pressure signal Pressure signal
180 200 ° CA TA G-Name
220
240
260
Value -1000 - 1000 0 - 17,3 0 - 17,3
280
300
320
340
360
Unit m/s² bar a bar a
Online 03.12.2007 10:21:04, , 299,9 1/min
PROGNOST Systems GmbH
Segmentation of on-line vibration signal with 1st and 2nd warning threshold 36 segments, each 10° crank angle, automatic monitor functions such as valve action and mechanical
integrity of piston drive to detect developing failures at early stages. V Cyl. 2F, Absolute maximum via 36 Seg. .. 10 degrees
m/s² 60
55
50
45
40
35
30
25
20
15
10
5 0
1
2
0
3
4 30
Machine 60-C1 002 2nd St Online 01.04.
4
5
6
7 60
8
9
10 90
Measuring Point V Cyl. 2F
11
12
13
120
14
15
16
150
Data name Absolute maximum
17
18
19
20
21
22
180 210 ° CA TAG-Name 60VT 10339
2008 13:00:01, 60-C-1002 2nd Stage - Absolute maximum via 36 Seg. .. , 200,2 1/min
23
24
25
240
26
27
28
270
29
30
31
300
32
33
34
330
35
36 360
Value Unit 0 - 2000 m/s² PROGNOST Systems GmbH
Pressure, piston rod load and rod reversal duration monitoring continuous monitoring of the rod reversal duration is an essential way to prevent failures of small end bearing based on underlubrication due to inadequate rod load reveral span of time.
Crosshead guide vibration and dynamic piston rod load derived from indicated pressure for one crankshaft revolution. The diagram shows an example with a damaged piston/piston rod-connection. The 95000 lb
TDC
BDC
TDC
78000 67500 56000 45000 33500 22500 11000 0 -11000 -22500 -33500 -45000 -56000 -67500 -78000 -90000 0
20
40
60
80
100
120
140
160
180 ° CA
200
220
240
260
280
300
320
340
360
Peak-to-Peak analysis of the piston rod position (operational run out) Displacement signals providing piston rod position are divided into 8 segments of 45° crank angle each for every revolution to detect critical mechanical conditions of the piston rod. The illustration shows two piston rod position signals: 60 m il
TDC
purple = normal position (“good condition”) green = strong fluctuations close to BDC (bottom dead center) due to liquids inside the compression chamber
BDC
TDC
45 30 15 0 60
75
90
10 5
12 0
13 5
15 0
16 5
18 0
19 5
21 0
22 5
24 0
25 5
degree crank angle R D S tage 1, P eak-P eak over 8 S eg. .. 45 d egrees
m il 40 30 20 10 0
1 0
15
2 30
45
60
3 75
90
10 5
4 12 0
13 5
15 0
5 16 5
18 0
19 5
6 21 0
22 5
24 0
7 25 5
27 0
28 5
8 30 0
31 5
33 0
34 5
36 0
degree crank angle
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Monitoring based on operating condition
Automatic detection of the operating conditions and threshold adjustment
Adaptive condition monitoring based on operating condition e.g. due to changing suction/discharge pressures to avoid false alarms because of changing operating conditions. Vibration in „operating condition 1“ (2200 bar)
Vibration in „operating condition 2“ (2600 bar)
Data acquisition and storage
PROGNOST®-SILver DCS - Process data
PROGNOST®-NT
Add/write new data
Ring buffer
Period
Sample rate
Captured data
Storage and capacities
10 minutes, gapless, every revolution selfoverwriting
25.000 samples/sec
All online signals and DCS values
- 10 minutes - Automatically on hard disc: 5 x start, 8 x stop, 10 x alarm, 8 x alert 5 x user = 36 different ringbuffer - unlimited storage on external disc / drive
Snapshot d a i l y
Short term trend
1 / day 1 revolution (e.g. 12:00h) selfoverwriting
25.000 samples/sec
365 days selfoverwriting
1 average / minute
All online signals and DCS data and all analyses
hh 6
- Automatic on hard disc - Complete time period can be storaged on interal or external disc / drive
All analyses and DCS data
min Long term trend
- 1826 days
- 365 days - Automatic on hard disc - Complete time period can be storaged on interal or external disc / drive
System lifetime 1 average / hour
All analyses and DCS data
- System lifetime - Automatic on hard disc - Complete time period can be storaged on interal or external disc / drive
PROGNOST Systems at a glance The systems and services of PROGNOST Systems are based upon many years of technical experience and competence in the acquisition, automated evaluation, and interpretation of condition data for reciprocating machinery. Asset Performance Management systems from PROGNOST Systems are the world-leading technology for the safe, reliable and economical operation of reciprocating machinery. Design and production of our systems takes place in Rheine, Germany. PROGNOST Systems office locations in Europe and USA, along with our worldwide partners, guarantee responsive and reliable on-site support.
Our customers Continuous dialog with more than 100 enterprises from the oil, gas, chemical, and petro chemical industry on over 400 PROGNOST installations contribute to the ongoing optimization of our product and services offerings. Our customers reward this focused approach with high marks for satisfaction and longstanding brand loyalty.
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Birkenallee 177
1020 Bay Area Blvd. Suite 118
48432 Rheine
Houston, TX, 77058, USA
Germany
Phone: +1 - 281 - 480 - 93 00
Phone: +49 (0)59 71 - 8 08 19 0
Fax: +1 - 281 - 480 - 93 02
Fax: +49 (0)59 71 - 8 08 19 42
Toll Free: +1 - 800 - 848 - 6677
Email: info@prognost.com
Email: infousa@prognost.com
www.prognost.com
05/2009
PROGNOST Systems, Inc.
TI_Flyer NT for Refining A4_01_EN
PROGNOST Systems GmbH