melaka refineary vib proposal

INSTITUTE OF NOISE & VIBRATION DIRECT TEL: 603-26154925

To: PETRONAS PENAPISAN MELAKA SDN. BHD. (PPMSB)

From: Professor M. Salman Leong

Fax: Pages: 6

Phone: Date: 3 December 2007

Attention: M Noor Lihin/ Salim Sumormo

PETRONAS PENAPISAN MELAKA SDN. BHD. (PPMSB) COMPRESSOR VIBRATION INVESTIGATIONS AND FINITE ELEMENT ANALYSIS SERVICES

We refer to our recent site visit with your staff at the Refinery, and the meeting of 30 November 2007 at our office. We are pleased to forward herewith a Technical & Fee Proposal for the above services.

We trust that the above are to your requirements, and shall be pleased to clarify any enquires you may have.

Regards.

DR. M. SALMAN LEONGProfessor and Director of Institute

Proposal for Petronas Refinery Compressors Vibration Investigations 1

UNIVERSITI TEKNOLOGI MALAYSIA

JALAN SEMARAK54100 KUALA LUMPUR

TEL : 603-26154931/26154924TELEFAKS : 603-26932854

PETRONAS MELAKA REFINERYCOMPRESSOR VIBRATION INVESTIGATIONS AND FINITE ELEMENT ANALYSIS SERVICES

INTRODUCTION

This is a proposal submitted by the INSTITUTE OF NOISE & VIBRATION, UNIVERSITI TEKNOLOGI MALAYSIA in response to a Request for Proposal a VIBRATION INVESTIGATION AND ANALYSIS for foundation vibrations of reciprocating compressors at Petronas Melaka Refinery.

It is our understanding that the structural foundation of the reciprocating compressors had suffered repeated failure (cracks) attributable to excessive vibrations. It is however need to be established if the foundation failure was a result of excessive vibrations from the compressor and piping system, or the excessive vibration induced by material failure in the foundation (cause and effect).

The objective of this VIBRATION INVESTIGATION AND ANALYSIS is to determine the nature and root cause of the problem. This work shall include animated visualization of the dynamic motion (Operational Deflection Shape) of the compressor train, piping and foundation at pertinent forcing frequencies such that the likely cause of the excessive dynamic motion could be identified. System and structural resonances shall also be investigated.

SCOPE OF WORKS

The Scope of Work for the VIBRATION INVESTIGATION AND ANALYSIS shall include but is not limited to the following:

VIBRATION MEASUREMENTS AND ANALYSIS

1 Undertake visual inspections on the entire compressor train installation with particular reference to the machine, piping, structural skid and foundation. The visual inspection shall be carried out with references to structural drawings and general assembly and layout drawings (to be provided by the Client prior to the inspections) where available.

2 Undertake measurements on the entire compressor train installation, piping at appropriate locations, supporting structural skid and foundation under controlled test conditions. Vibration measurements shall be undertaken using multi-channel analyzer with multiple accelerometers in three axes simultaneously.


3 Vibration measurements test conditions shall different flows and/or operating speeds. Additional measurements shall include transient measurements during a run up and coast down where feasible.

The vibration measurements shall include FFT vibration spectrum, phase angles (referenced to a suitable force input location) at a series of controlled operating speeds where appropriate.

4 If an equipment shutdown can be arranged, undertake an impact excitation test(s) of the entire compressor installation and connected pipes/ structures (with the unit not operating) such that resonant frequencies of the installation, pipes and supporting structure can be identified. Measurements shall be undertaken using multi-channel analyzer with multiple accelerometers such that mode shapes can be obtained from the impact tests.

The above requires a temporary shutdown of the unit (and nearby rotating equipment if possible) for this dynamic testing.

5 Undertake an Operational Deflection Shape (ODS) study using the measured data to examine the deflection shapes of the compressor train, piping and supporting structure / foundation under operating conditions.

The purpose of this study is to enable visualisation of the dynamic motion of the entire machine installation, structure and pipes such that critical areas of forced response could be identified. This study shall be undertaken using post- vibration analysis software (MEScope or equivalent).

This Operational Deflection Shape analysis shall provide animated visualization of the dynamic motion of the compressor train, pipes and supporting structure. This shall provide a visual insight to the nature of the motion and correspondingly likely source(s) of the vibration problem.

6 Consolidate findings of the above measurements and analysis with respect to structural vibration responses correlations with forcing excitations, phase relationships and Operational Deflection Shapes/Modal Analysis.

7 Review conceptual structural modification options and/or other vibration reduction measures using results of the Operational Deflection Shape study.

8 Report and Documentations of the above site measurements, post site data reduction and vibration analysis, and recommendations for remedial measures.


FINITE ELEMENT ANALYSIS

9 Review structural and piping drawings for the RC structure, and all attached piping for information to build up a computational Finite Element Model. The FEA model shall consist of 3 dimensional solid elements where appropriate to represent the compressor block, piping, structural skid and foundation.

10 Assign material and constraints input for the FEA model, including compressor interfacing with concrete plinth.

11 Undertake normal modes analysis to determine natural frequencies and mode shapes for the compressor train, piping and structural skid/foundation system. Results shall be checked against measured data of natural frequencies and mode shapes identified in the vibration measurement for the compressor train. The FEA model shall be fine tuned, and if necessary with adjustments to material properties and constraints such that computational results are fairly similar to actual measured results. Results shall include animation of the natural modes to be compared against existing measured modes.

12 Based on measured acceleration levels in the compressor, determine likely force and moment reactions acting on the compressor train and foundation. With these forcing estimates, undertake a forced harmonic response analysis of the FEA model (whose normal modes had been validated). The vibration response as predicted from this FEA analysis shall be checked against actual measured vibration levels on the structure at all locations of interest. If necessary, refinements to the forcing functions shall be undertaken to further fine tune the FEA model and forcing functions to represent existing conditions.

13 From the FEA model whose dynamic motion is validated, obtain stress profiles for the entire structure and foundation in particular. Stress generated from combined static and dynamic loadings shall be reviewed and assessed against likely failure modes and acceptable threshold levels. Acceptance limits shall be based on Petronas Technical Specifications, where applicable, and/or Euro Codes.

14 Based on the above model, further FEA analysis shall be undertaken with particular emphasis to stress concentration points/stress risers and if necessary cracks located at strategic locations at hold down bolts locations to validate likely failure modes and locations.

15 Undertake repeat FEA analysis for cases involving forcing input that’s detuned from existing natural frequencies and/or with structural modifications and foundation redesign where appropriate. The FEA model shall also be used to consider any structural modifications to the piping systems and/or structural skid and foundation.

16 Report and Documentations of the above analysis.


DELIVERABLES

Deliverables of the VIBRATION INVESTIGATION AND ANALYSIS shall be a formal REPORT documenting the vibration measurements, vibration deflection shapes, and analysis. Recommendations and solutions for vibration induced failure mitigation shall also be included as appropriate.

INFORMATION AND DOCUMENTS REQUIRED FOR STUDY

The following documents and information shall be required:

- Equipment layout drawings for the equipment installation including all connected pipes;

- Structural drawings showing the supporting structures, skids, and platforms for the compressors installation;

- Information relating to operating speeds and process loading conditions.-

MANPOWER

Personnel proposed for this VIBRATION INVESTIGATION AND ANALYSIS are as follows:

SPECIALISTS Ir Dr M. Salman Leong(Professor/Principal Consultant)

ENGINEERS Tan Chek Zin GuaiYeu Kae.

The Principal Consultant shall be Professor Ir Dr M. Salman Leong from the Institute of Noise & Vibration, Universiti Teknologi Malaysia. He has more than 25 years experience in Mechanical and Structural Vibrations. His experience includes vibration analysis, modelling, predictions, measurements and assessment. His experience includes petrochemical plants, offshore platforms, power generation plants, and heavy industrial facilities. Assistance on site for vibration measurements and off site data reduction shall be provided by the Engineers.

The Institute and Professor Salman Leong in particular had similar experiences in troubleshooting and resolution of foundation and bearing pedestal failures of turbo-machines. Similar work for structural vibrations and Finite Element Analysis were also recently undertaken on a Petronas facility with Petronas Global Solutions.


PROFESSIONAL FEES

Professional fees are charge on a lump sum basis based on estimated man hours required for this Project:

Professional Services

i Vibration Measurements and AnalysisScope of Work Items 1 to 8 RM 45,000.00

ii Finite Element AnalysisScope of Work Items 9 to 16 RM 35,000.00

Total Fees RM 80,000.00

iii ReimbursementsOut of pocket expenses for travelling and accommodation. RM 1,500.00

Any extension of work to the above consultancy brief shall be to prior mutual agreement, and charge at RM400.00 per man hour for a SPECIALIST and RM 180.00 per man hour for an ENGINEER.


melaka refineary vib proposal

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