Online System Case Studies

Dylan Abel

Windrock, Inc.

Overview

• Background Information

• Windrock Online Monitoring System

• Case Studies: Ring Leakage

Cylinder Winking

Discharge leak

Background Information

• Southeast Oil Refinery

• Compressors: 4 Throw Dresser Rand

3 Throw Dresser Rand

• Gas: Hydrogen

• Speed: 327 RPM

• 4 Throw Windrock On-Guard Monitoring Equipment: HP-Guard, V-Guard, and P-Guard

• 3 Throw Platinum Online Monitoring System

Windrock On-Guard System

• HP-Guard Monitoring:

1. Head End Pressure

2. Crank End Pressure

• V-Guard Monitoring:

1. Crosshead Vibration

2. Frame Vibration

• P-Guard Monitoring:

1. Rod Drop

2. Rod Run Out

Windrock On-Guard System

HP-Guard Specifications

• HE and CE pressures

• TDC input

• Comm and Modbus outputs

• Relay protection

V-Guard Specifications

• 8 accel channels

• TDC input and output

• RS-485 Comm and Modbus outputs

• Relay protection

• 24V Aux power

P-Guard Specifications

• 12 input channels

• TDC input

• RS-485 Comm and Modbus outputs

• Relay protection

(Rod Drop and Rod Run Out)

Case Study: Ring Leakage

• Customer did not think that ring leakage was showing up in the Windrock data

HP-Guard Data: Dec. 1, 2014 (Before)

HP-Guard Data: Jan. 19, 2015 (Leakage)

HP-Guard Data: Jan. 22, 2015 (Repaired)

V-Guard Data: Crank Angle

Before Repair

After Repair

V-Guard Data: Trend (Leakage Effects)

Before

V-Guard Data: Trend (Leakage Effects)

Leakage

V-Guard Data: Trend (Leakage Effects)

Down For Repair

V-Guard Data: Trend (Leakage Effects)

Repaired

Windrock MD Report Data: Jan. 19, 2015

Windrock MD Report Data: Jan. 19, 2015

Windrock MD Report Data: Jan. 22, 2015

Windrock MD Report Data: Jan. 22, 2015

Overall Analysis

• Ring leakage could be detected before the compressor crashed in both the PV curves and vibration

• First, the PV curves had crossovers and rounded toes, which could eventually be seen in the vibration traces

• Ring leakage could have been caused by contaminated gas, excessive lube rates, ring groove issues, etc.

• Cylinder 3 had its rings replaced, but still has suction leaks

Case Study: Cylinder Winking Problem

• Cylinders were coming loose at the distance piece and yoke connection

• “Winking” is a term used by Dresser Rand

Accelerometer Install Photos

Yoke and Distance Piece

Theory

𝐶𝑦𝑙𝑖𝑛𝑑𝑒𝑟 𝑊𝑖𝑛𝑘𝑖𝑛𝑔 𝑅𝑎𝑡𝑖𝑜 = 1 −𝐷𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑃𝑖𝑒𝑐𝑒 𝐼𝑃𝑆

𝑌𝑜𝑘𝑒 𝐼𝑃𝑆

• If the cylinder winking ratio is greater than 0.35, then the cylinder is loosening

• The 0.35 warning value was calculated by the companies engineer

Windrock MD Setup

Trend Data

Overall Analysis

• This company is using the calculated points to monitor their problem and help them find a solution

• Many companies do not use the full capabilities of Windrock MD

• Windrock MD can have calculated trend points, such as the cylinder winking ratio

Platinum Online System• Platinum Monitoring

1. Head End Pressure

2. Crank End Pressure

3. Crosshead Vibration

4. Frame Vibration

5. Rod Drop

6. Rod Run Out

Platinum Online System

Theory

𝐹𝑙𝑜𝑤 𝐵𝑎𝑙𝑎𝑛𝑐𝑒 =𝐶𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑒𝑑 𝑆𝑢𝑐𝑡𝑖𝑜𝑛 𝐹𝑙𝑜𝑤 𝑅𝑎𝑡𝑒

𝐶𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑒𝑑 𝐷𝑖𝑠𝑐ℎ𝑎𝑟𝑔𝑒 𝐹𝑙𝑜𝑤 𝑅𝑎𝑡𝑒

• Flow balance > 1 indicates gas is leaking out of the cylinder into a low pressure area, which points to a suction leak

• Flow balance < 1 indicates gas is leaking into the cylinder from a high pressure area, which points to a discharge leak

Platinum Pressure Data

Platinum Trend data

Overall Analysis

• The pressure curves and trend data both indicate that the crank end has a discharge leak

• The discharge leak means that gas is leaking into the cylinder from a high pressure area

Conclusion

• Use all available data to support conclusions when analyzing a problem

• Case Study 1: Ring Leakage

PV with theoretical, crank-angle vibration, and vibration trends

• Case Study 2: Cylinder Winking

Calculated parameters can help in identify a problem

• Case Study 3: Discharge Leak

Flow balance trending is helpful with valve leaks