Solutions for Seawater-cooled Air Conditioning Systems

• Introduction
  • Microfouling / Biofilm
  • Macrofouling
• Benefits
• Case Studies

Seawater-cooled air conditioning system is normally adopted when the chiller plant is nearby harbour or seashore. Seawater-cooled system has relatively high efficiency due to the comparatively constant and low sewater temperature. It is further divided into direct and indirect configuration. Direct seawater cooled system has the highest efficiency but the maintenance to the condenser tube or the titanium condenser is costly.

To reduce the maintenance cost of direct seawater-cooled equipment, plate heat exchange made of stainless steel or titanium is used to prevent the condenser from corrosion caused by seawater. Athough the closed loop condenser circuit is then easier to maintain, the efficiency is compromised as the heat exchange is not 100% in efficiency. Moreover the cleaning of such plate heat exchange is labour, parts and time consuming.

Biofilm developed on the condenser creates a very large thermal barrier to the media for heat exchange. Tradtionally chlorinator is used to generate chlorine from seawater and kill the micro-organism and seashell. However the allowable concentration of chlorine discharged to the sea is governed by law to protect the environment and therefore the fouling problem is not eliminated.

In case of indirect seawater cooled system, the efficiency of plate heat exchanger is dropped dramatically when biofilm developed on the plate surface and macro-fouling block the passage of water flow. Therefore frequent cleaning is required to maintain a high differential temperature between the primary and secondary side.

Click here to see how we solve the biofilm problem.

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In a typical design, a strainer is usually put before a seawater-cooled condenser or plate heat exchanger so as to prevent the devices from blocking by macrofouling such as seashells. No matter how small the size of the screen of a strainer, the larvae of these animials can pass through it and adhere to surface of pipe or devices where they accommodate and grow.

When they are large enough to block the condenser tubes or plate heat exchanger, the condenser approach increases and cleaning of devices is required.

HydroFLOW P Range does not kill the seashell directly. Instead the habitat and food supply is broken by killing the micro-organism that seashell rely on. Click here to see how we kill micro-organism effectively.

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Benefits

HydroFLOW P Range tackles microfouling and macrofouling existed in seawater-cooled air conditioning systems in an innovative, reliable, cost effective and environmental friendly way. The benefits that an HydroFLOW P Range can bring to you is numerous and summarised as below:

- Energy Efficiency of Chillers Maximized

Biofilm have a very poor thermal conductivity which reduces system performance and at worst leads to system shut down. The heat transfer coefficent is now brought to its designed value. Thus no more energy is lost due to the tube fouling.

Moreover the macrofouing reduces water flow and lowers the heat rejection. Now the problem can be minimized by the removal of microfouling and hence the loss of efficiency of chiller can be further reduced.

- Equipment Down Time and Maintenance Cost Reduced

The cleaning of tube or plate fouling demands manpower, parts, material and time. The interval and duration of cleaning is dramatically reduced.

- Low Power Comsumption

It consumes 15W - 65W (depends on the model used) for its operation. The electricity cost of it is negligible for continuous operation.

- Ease of Installation

It is a non intrusive method and installation can be completed within an hour provided that a single phase power socket is available. There is no change in the pipework and the original equipment.

- Minimal Attention Required

It builts on latest low power solid state technology and its typical power consumption is less than 45W. There is no problem of fatigue, wear out, over-heating and fast aging. It is maintenance free and the only attention to it is to make sure the two LEDs on the control unit are lit up.

- Environmental Friendly

Less water is used for cleaning of devices and less energy is consumed due to the minimized tube or plate fouling by the use of HydroFLOW P Range.

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