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From fishing boats and container ships, to military vessels and oil drilling platforms, in climates ranging from the excessive heat of the tropics to the bitter cold of the polar regions, those vehicles and facilities need cooling of heating. That is why hydronic systems have an important role in marine projects too.
They not only might be used to provide comfort to prestigious ocean cruise ships, but might also be used to preserve goods through temperature control, or might be used in process applications to cool down equipment used on oil rigs or offshore wind energy platforms.
All those activities require the use of chillers, which usually must operate using sea water and must stand harsh environmental conditions.
So, chillers need to be designed for this, so they can perform and last, meeting project requirements.
But what are the aspects that need to be considered when choosing a chiller for a marine application?
Operating envelope
Chillers designed for marine applications are usually required to operate using sea water at the condenser, and that, based on geographical areas where the chiller will have to operate, or based on season, implies the ability of the chiller to work with different sea water temperatures, even though they are usually designed to operate at condenser water temperatures of 32 °C.
In fact, the possibility that chillers could be required to operate at even higher temperatures should be considered.
That could be the case of a cruise ship docking in a port where sea water temperature is higher than 32°C up to about 35°C, for instance. The cruise ship will still need cooling, then the hydronic system will have to still be able to meet the cooling needs of the vessel.
Daikin has been providing products for the marine business for years now, constantly meeting the needs of an ever-changing sector, which has been requiring a steady technological evolution in terms of solutions developed and offered to the market.
To do that, Daikin not only can count on a several decades long experience withing the sector but can also take advantage of a dedicated structure supporting Daikin’s effort towards this sector.
That is how Daikin has been able to meet the most challenging requests in terms from the most important companies in the naval, or the oil and gas sectors.
Energy efficiency
Energy efficiency is a key aspect in marine projects as it is in other applications, and operative costs count as in any other project, especially now that the cost of energy has skyrocketed.
So, it is clearly preferable disposing of chillers that are highly efficient. But overall efficiency of chillers, in most of the marine contexts, depend on the ability of the chiller to operate efficiently at part load.
Part-load efficiency refers to the ability of a system to handle energy use at part load and should be taken into consideration when specifying a chiller, so that it can deliver the exact load requirement with the minimum power input.
Part load efficiency is more and more important for chillers as hydronic systems spend most of their operating hours at conditions different than design conditions. In fact, looking at a typical cooling load profiles in marine applications, we might notice that chillers often operate at part load conditions, because the cooling demand might change based on variables such as season, sea water temperature variation, occupancy, or workload of machinery.
So, chillers will operate most of the time off-design, but they will need to perform efficiently and reliably anyway.
That can be addressed using inverter technology or Variable Frequency Drive – an electronic power component that, by varying the frequency of the motor power supply, modulates the compressor rotational speed and in such a way controls the compressor capacity.
Daikin offer inverter technology across the entire product portfolio, being able to combine it with different compressor technologies and refrigerants.
The most relevant solutions for marine application are certainly the combinations of inverter technology with screw compressors and centrifugal compressors – both in-house designed and manufactured – and refrigerants ranging form R-134A to R-1234ze, as well as R-513A.
The high flexibility in terms of configurability of Daikin’s solutions for the marine sector, allow to design chiller units that can perfectly meet projects requirements, always providing high energy efficiency in all the contexts the units will have to operate.
Free Cooling
Another feature that might be important to increase energy efficiency in marine projects, is free cooling.
With Free cooling we refer to the ability of a chiller to use low external water temperatures to assist in chilling water, which then, can be used for comfort or process cooling, notably increasing the hydronic system’s energy efficiency.
But how does free cooling work?
Essentially, when outdoor temperatures are favorable, chillers can turn off compressors and take advantage of the low outdoor temperature to chill water.
For marine applications, this is a very relevant feature when condenser sea water temperature goes below about 6°C, allowing compressors to stop, and use the low external water temperature to chill or assist in chilling water.
Daikin offers this feature within the single compressor single stage centrifugal chiller range DWSC-C.
Compactness
In marine projects, making the most of the space available, is usually needed, as tight mechanical rooms or small HVAC plants are often involved. That happens mainly for the structural constraints, but it also happens – in the case of cruise ships, for instance – because the more is the allocated space to guest rooms, restaurants, and all those services, the better is the customer experience, and the more profitable will be the business.
That is are just an example among the reasons why marine projects usually require compact chiller solutions.
Daikin is very aware of that and has always worked to provide solutions that could integrate both contained size and performance, not just making chillers as compact as possible, but also offering the possibility to install units’ components such as the electrical panel, away from the unit, having it working remotely. The panel can even be installed in a different room than the one accommodating the chiller, simply using longer cables to connect the control panel to the chiller, offering a perfect solution for those applications requiring optimization of space.
Reliability
Hydronic system’s reliability in marine projects is fundamentals, as not only chillers are used to ensure continuity of operations on oil rigs and offshore platforms, but are also used to ensure comfort on vessels and make customer experience memorable on cruise ships.
As hydronic systems breakdowns could have a negative impact on business and brand, with the costs associated with activities shutdown or loss of reputation.
Daikin can ensure the high reliability of their products thanks to the quality procedures and the tests extensively performed during the entire cycle of manufacturing.
And finally, as a guarantee of the correct functioning of the chiller chosen, Daikin allows customers to test the machines before shipping to the project site. This is a possibility for customers, who can visit the factory and see with their eyes their chillers being tested at design conditions recreated in dedicated climatic chambers. This not only allows customers to verify that the unit chosen is working correctly, but also that it can meet cooling, efficiency, and noise emission targets.
Would you be interested in visiting the Daikin factories where the mentioned technologies are designed and manufactured? Then, get in touch here