1. The key to stable operation of the chiller: strictly control the quality of circulating water
Many users, to save costs, directly use seawater, groundwater, or simply treated water as circulating water, thinking that as long as it can circulate, it's fine. In reality, the evaporator of a chiller alternates between hot and cold for long periods, which requires very strict water quality.
To ensure stable long-term operation of the chiller, the circulating water must be pure, free of impurities, salts, and corrosive substances. This is the basic condition for proper equipment operation and the key to extending the evaporator's lifespan.
Non-pure water sources generally carry corrosion risks, with seawater being the most harmful. The high salt content and chloride ions in seawater are extremely corrosive, and even after basic filtration or desalination, the remaining substances can continue to erode the metal evaporator.
Seawater corrosion is slow and continuous; early on, it only causes slight scaling and reduced heat transfer, which is hard to notice. Once obvious damage occurs, it's usually irreversible, like wall perforation or refrigerant leaks, and typically parts have to be replaced.
2. Suitable Scenarios and Limitations of Copper Evaporators
Standard chillers usually come with copper evaporators, which have fast heat conduction, high heat exchange efficiency, and great cost performance. They are ideal for standard conditions like purified water and clean tap water and can meet the long-term usage needs of most ordinary industrial scenarios.
However, copper isn't very corrosion-resistant and is very sensitive to salt, chloride ions, and acidic or alkaline impurities. In highly corrosive water environments like seawater or brackish water, it's prone to pitting, oxidation, and pipe blockages, which can ultimately damage components. The recent issue with our Saudi customer is a typical case of mismatched operating conditions.
So, copper evaporators are only suitable for clean, normal water. They're not recommended for high-corrosion scenarios like coastal areas or seawater circulation. Don't take chances trying to use them there, or it could lead to equipment and production losses.
3. Best solution for highly corrosive water conditions: upgrade to titanium evaporators
For special conditions like coastal areas, seawater circulation, and chemical-corrosive water quality, the most reliable and mature way to solve corrosion problems from the source is to upgrade the evaporator material. Compared to copper, titanium has extremely strong corrosion resistance, oxidation resistance, and scale resistance, effectively protecting against erosion from seawater chloride ions and acidic or alkaline media. Upgrading from a copper evaporator to a titanium one can perfectly handle all kinds of corrosive water and completely prevent corrosion failures and equipment downtime. Although titanium equipment has a higher initial cost, it can significantly reduce hidden costs like maintenance, parts replacement, and production stoppages, while offering a longer lifespan and clear long-term value.