Final Report - 2013-227-DLD- Tactical Research Fund: Addressing the urgent need to identify viable refrigerant alternatives for use in the Northern Prawn Fishery
This study highlights significant challenges facing both the Northern Prawn Fishery (NPF) and Sydney Fish Market regarding future refrigeration options. With respect to the NPF, this study highlights significant persisting uncertainty regarding the only currently suitable alternative (HFC-507A), and emphasizes the need for unified action on this issue to minimise cost to individual operators. Options are presented for Sydney Fish Market, and risks identified.
Principal Investigator: Peter Brodribb
Keywords: Refrigerant, Northern Prawn Fishery, Sydney Fish Market, R22, ammonia/CO2.
Modern fishing fleets and the fish product supply chains are entirely dependent on effective and reliable refrigeration systems, from the point of catch to consumption.
The fishing vessels of the NPF (Northern Prawn Fishery) have one of the most demanding tasks for refrigeration equipment, operating in constrained spaces, under heavy load, in high ambient temperatures,requiring snap freezing of tonnes of sensitive product using equipment operating in a moving vessel, with heavy vibration and exposed to corrosive salt spray and water. Aside from the severe mechanical constraints and conditions, this demanding refrigeration task is only easily achieved using HCFC-22 (R22), a refrigerant that is on the verge of being completely phased out within a matter of years.
Further down the supply chain, the very large refrigeration system around which the SFM (Sydney Fish Market) is built, is also at the end of its design life and reliant on more than half a million dollars of the same refrigerant, HCFC-22. Aside from the logistics of replacing a working system of this size, in a facility that requires 7 days per week operation to maintain the stock in trade, the locality of the SFM, on the edge of the largest CBD in Australia, in the middle of an active tourism, retail and hospitality precinct, means that the use of certain refrigerants that have potential safety issues is unlikely to be acceptable, even though they may be the best technical solution to the requirements.
The proposed shift from the Department of Environment towards the use of low GWP refrigerant such as natural refrigerants has highlighted a need to urgently consider alternative options suitable to fishing operations in the NPF, and review practice and system design changes that may be required.
Additional factors including the significant distance between fishing grounds and ports, limited ability of vessel engineers to maintain complex refrigeration systems, and significant dangers associated with use of highly volatile refrigerant alternatives also necessitate use of safe, simple, reliable refrigeration systems, further limiting adaptive options able to be applied to NPF vessels.
There is an urgent need to review options able to be applied to NPF fishing systems and identify an uncomplicated, reliable, high capacity, compact and inexpensive solution.
1. Undertake detailed review of refrigerant alternatives to R22 that can be applied on NPF vessels. Evaluate associated advantages and disadvantages of each, including an estimate of the costs per vessel associated with implementation of alternatives.
2. Identify a simple, cost effective, reliable solution to the impending phasing out of R22 in Australia.
3. Extend key findings to target audiences - particularly NPF operators, government officials and political representatives.
4. Explore technology options for the large R22 system located at the SFM.
Northern Prawn Fishery Fleet
There is no easy ‘off-the-shelf’ solution for the NPF fleet. Refrigeration engineers and practitioners with specialist knowledge and experience in dealing with this tough and complex application must devise the next generation refrigeration system.
The only refrigerant that is entirely suitable for delivering the workload required for the exiting NPF vessels is HFC-507A, a refrigerant that will come under regulatory scrutiny within the next decade (or sooner), and face a similar fate as HCFC-22.
It is not recommended that any vessel owner proceed with paying to replace their system until the timing of a proposed removal of the carbon equivalent import levy change is confirmed.
The most efficient way to manage the transition for the fleet is for the industry body to invest in a vessel technical standard and demonstration system. New refrigeration systems can then be ordered with delivery and installation dates scheduled for post the removal of the levy, ensuring reasonable prices are paid for gas.
Sydney Fish Market
Site specific constraints may prohibit an advanced ammonia/CO2 cascade system, and the most appropriate system for the site would appear to be a HFC-134a/CO2 cascade system.
It is recommended that the Board consider conducting a detailed feasibility study into the design and development of an advanced HFC-134a/CO2 cascade system. Should the board choose to embark on additional engineering, the ammonia/CO2 system would eliminate any future scrutiny from government regulators on HFC refrigerant usage.
Given the size of the HCFC-22 charge required to operate the existing SFM plant, and the age of the equipment, the option of simply extending the life of the existing plant for long enough that an effective and affordable low GWP fourth generation refrigerant becomes available, comes with ever increasing risk of both component failure, and rapidly escalating HCFC-22 gas prices.
Please follow the link to the supplementary report Refridgeration from Catch to Market: A study of refridgeration technology options for the Northern Prawn Fishery fleet and the Sydney Fish Market