The Environmental Group Limited

Gas Cleaning System

Year 2021
20% concentration of SO₂

Prominent energy supplier in the Australian Energy Market

Year 2021

Location: Australia 

THE Project

Client is a prominent energy supplier in the Australian Energy Market, with 8 gas turbine power plants, 1 coal fired power plant, 1 hydro power plant and 2 solar farms, with plans to retire its only coal fired power plant in 2 years it will be reliant on Gas turbines and battery storage to provide rapid response with renewables are not available.

The client experienced premature failure of their silencers, occurring after just 900 starts despite only being in operation for 5 years. The original equipment manufacturer (OEM) lacked an upgraded design and proposed continuing with the existing one, which had a design life of under 10 years. Given the power station’s higher-than-expected start frequency, there was a need for a silencer tailored for peaking applications. Additionally, stringent far-field noise regulations were imposed on the power plants, necessitating a solution that would enable uninterrupted 24/7 operation without surpassing noise limits and causing disturbance to nearby residents.

The challenge

The perforated sheets, serving as structural bracing for the silencer splitters (baffles), were welded to the frame. However, due to thermal cycling, these welds were prone to cracking, leading to the escape of acoustic insulation and a decrease in the silencer’s effectiveness. Moreover, there was a safety concern regarding the perforated sheets breaking off and being expelled from the stack. Additionally, the dimensions and weight of the splitters caused the splitter frame to deform due to the heat from the exhaust.

Key outcome

  • Quantifiable outcomes and achievements.
  • Successful creation of silencers that have an operational life for 15years with a minimum of 3000 starts.
  • Metrics, statistics, or improvements observed.
  • Project was delivered on time and on budget.
  • The desired noise levels of less that 43dB at 400m from the turbine exhaust levels were achieved.

THE solution

Baltec designed the new silencer using Finite Element analysis to determine stresses and buckling loads, thermal stress analysis to determine how the silencer behaves when exposed to the exhaust gas at 650oC. 3D modelling allowed us to test and ensure that the new silencer would fit on the existing support structure that was retained. We fabricated the complete silencer and lower transition, overseas and transported the 300 Tonne structure in segments to the site where the client erected the equipment.  To reduce installation time, it was decided that the assembly of the silencer will be done on a support stand from ground level and the whole structure weighing 300 Tonnes would be lifted in two lifts, so the silencer shell was designed to safely pick up the entire structure.

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