December 2, 2024 in News
Walker Fire Protection Wins “Champion in Diversity Aw...
Walker Fire Protection is delighted to be recognised by the National Fire Industry Association (NIFA) as the “Champion in Diversity Award” winner ...
540 Wickham Street Fortitude Valley QLD
The Australian commercial building market is on a clear path towards electrification.
So, when it came time for an iconic property in Brisbane to decommission its gas-fired cogeneration plant, the technical expertise of the A.G. Coombs Group was called on to deliver a project close to home.
Role of A.G. Coombs
- Cromwell Property Group engaged the expertise of A.G. Coombs Advisory to assess the environmental impact of their 1900kVa gas-fired cogeneration plant on the building’ environmental ratings.
- A.G. Coombs Advisory were then engaged to draft replacement specifications for the cogeneration plantand provide technical support during the tender process.
- A.G. Coombs were awarded the project under a traditional Design and Construct (D&C) contract. A.G. Coombs Advisory continued to provide technical assistance to the client throughout the project.
Objectives
The project aimed to help reduce the buildings carbon emissions in 3 ways:
- Decommissioning the gas fired cogeneration plant. The owner was able to purchase green power from renewable sources.
- Selecting a more efficient electric chiller to replace the absorption chiller providing low and mid load cooling which is required for about 80% of normal operation.
- A chiller using a hydrofluoroolefin (HFO) refrigerant was selected, with a Global Warming Potential (GWP) of one, HFO is equivalent to carbon dioxide (CO2), unlike similar chillers with refrigerants having a GWP over 1400.
Approach & Methodology
- The investigation considered the plant’s maintenance and life cycle, the building’s standby power demands, the fluctuating energy costs, and a decarbonised electricity grid, especially the upcoming changes to NABERS Energy rating emissions factors.
- A.G. Coombs Advisory found that replacing the cogeneration set with a magnetic bearing, water-cooled electric chiller, and a standby diesel generator for essential services could improve the HQ North tower’s NABERS Energy rating to a market-leading 6 stars. Using HFO (R1233zd) refrigerant further reduced the site’s Scope 1 emissions.
- A waste minimisation strategy ensured many plant components were reused: The gas-powered generator in outback Australia; urea in another trigen plant; lithium bromide in an overseas absorption chiller; and various spare parts to extend other plants’ lives. The absorption chiller, redundant cable, pipework, and flues were also recycled.
Image: Ross Pottinger
Challenges
- The works presented a major logistics challenge to minimise disruption to the building and tenants, and safely remove the heavy plant.
Outcomes
- Careful planning limited service shutdowns, with a temporary generator providing essential standby power until the new diesel generator and systems were complete. A pre-commissioned controls and mechanical electrical board replaced the existing one, addressing arc flash safety by allowing Main Switchroom control from outside, eliminating the risk of switching near 3200Amp circuit breakers.
- The plant’s replacement reduced operational costs and optimised plant room space, benefiting the onsite facility management team. Using a diesel generator for standby power simplified plant operation and maintenance while increasing system reliability.
- The new electric chiller plant will contribute significantly to Cromwell Property Group’s net zero emissions goals, while reducing complexity and providing significant savings in plant maintenance.
