Centrifugal compressors, pressure regulating systems and pipe control units are the vital equipments for compression and transport units, for different services in the field of oil and natural gas. These are a major noise source especially when used close to inhabited areas where the European Community regulations on environment protection apply. As a compressor uses mechanical power (gas turbine, steam turbine or electrical motor) to compress gas, it is inevitable that a small part of the mechanical energy transforms into acoustical energy during the compression process. The acoustical energy travels downstream and upstream through the compressor system and manifests itself into noise and vibration, both in system and in the vicinity of this. Typically, the internal acoustical energy finds its way to the ambient through the path of less resistance. In a compressor system, the inlet and discharge pipe are more susceptible to noise transmissions that the compressor case because the process pipes connected to the compressor have thinner walls, concentring the propagation of noise and vibrations. This wall thickness disparity makes the inlet and discharge pipes more vulnerable to the internal acoustical excitation. The noise and vibration are directly attributed to the internal aero acoustic source. For centrifugal compressors, the dominant part of the acoustic source is caused by the pressure pulsations that are inherently produced during the compressor operation. As the internal aero acoustic source propagates waves through the compressor flow path and the process pipes, it couples to the structure and causes the structure to vibrate and to radiate noise. Pressure pulsations are the dominant source of piping vibration and noise emission. In accordance to the above mentioned, the main vibration and noise source in a gas compression unit is the centrifugal compressor. There are also secondary vibration and noise sources. These are: the flow measurement elements (diaphragms), inlet-outlet and flow regulation elements, bends and section variations for the inlet and outlet pipes.

The project intends to identify noise and vibration sources and to produce silencers with a specific geometry that should act on the vibrations, as well as on the noise. The in-line silencers we want to install in the discharge and inlet pipes are very complex, as we intend to obtain a significant reduction of over 15 dB(A). Till now the only method used was isolation by covering the structure; this did not reduce the internal acoustical energy, which led to structure damages. The solution within this project intends to reduce internal acoustical energy and disrupt vibrations by using Helmholtz resonators and low frequency pressure pulsations reduction units.

Besides, a new active monitoring system, based on new software, will be made within the project, to allow remote visualization, showing real time values for the noise and vibration parameters of compression units.

General objective

The objective of this project proposal is noise and vibration reduction from technologic units within the natural gas compressors and regulation-measurement, as well as creating a new software to remote monitor the working parameters as well as the noise and vibration parameters. In order to reach these objectives, the project proposal aims to design and create an INTEGRATED SYSTEM made of in-line silencers in the discharge and inlet pipes, to improve the acoustical performances of the regulation and measurement units within the compression units, as well implement a new active monitoring software, cheaper and accessible. The complexity of solving environment issues within natural gas compression units and the purpose of reaching a 15 dB(A) reduction implies development of knowledge in the field.

The results of the research activity will be: an innovative product, the INTEGRATED SYSTEM for noise and vibration reduction and the active monitoring software, articles published based on the experiments prior and after starting the noise reductors, young graduates who may continue their studies (masters and PhD) starting from this research theme, as well as conferences organized by the consortium for a good dissemination of the results.

Consortium

CO - www.comoti.ro - INCDT COMOTI BUCHAREST

P1 - www.upb.ro - POLITEHNICA UNIVERSITY BUCHAREST (UPB)

P2 - www.upg-ploiesti.ro  - UNIVERSITY OF OIL AND GAS, Ploiesti (UPGP)

P3 - www.sintactic.ro  - SinTactic Group S.R.L.  (SG) - Removed from consortium according to AAd nr. 2/2010

P4 - www.transgaz.ro - NATIONAL SOCIETY OF NATURAL GAS TRANSPORT “TRANSGAZ” S.A. -Medias (SNTGN)

The activities and responsabilities of each partner

Stage I. Hypothesis and theories on acoustical pollution caused by technological units, inlet-outlet and flow regulation elements, bends and natural gas compressors on high population density areas. Innovative methods to reduce noise and vibrations - CMT, UPB, UPGP, SG, SNTGN
Stage II. Laboratory and in-situ experimental research aiming to establish new efficient solution to reduce noise which will be practically applied.Responsible: CMT; Partners involved:   CMT, UPGP, UPB
Stage III. Elaborating the noise reduction solution documentation. Experimenting in laboratory the noise reduction solution. Designing the EEISG-COMOTI centrifugal compressor noise reduction solution. Monitoring system designing and software development. Responsible: CMT; Partners involved:   CMT, UPB
Stage IV. Improved EEISG-COMOTI centrifugal compressor execution. Realizing the monitoring system. Put in service and demonstrating the utility and functionality of the entire system. Large scale results dissemination. Responsible: CMT; Partners involved: CMT, UPB, UPGP, SNTGN;