Precise Measurement & Control of Cooling Water Distribution System

Task

In the cooling applications of Radio Frequency and Semiconductor Components, special water based coolants circulate from a chiller to different lines. These coolants are expensive so they require to be monitored with precise measurement and control for round the clock operation.

The circulated coolant changes its properties (pH and conductivity) during the continuous operation so is required to be treated in the main treatment plant in order that pH and TDS can be maintained, enabling the costly cooling water to be re-circulated. The challenge was to effectively distribute the coolant from the main chiller at 16 bar pressure to a combination of supply and return lines at required fl ow rates. In order to achieve the goal of precise control, the system would be designed and fabricated in stainless steel grade 316, with local and remote indicating process instruments for temperature, pressure and flow.

All the process instruments had to be installed on individual branches with remote transmission output for precise control by SCADA at a remote location. Minimum pressure drop, space restriction and complexity of zero leakage in the system were other constrains.

Solution

From Kobold’s comprehensive range of process instruments were a selection of products that satisfied all the requirements of the customer due to their high accuracy, compact size, local LED indication, flexible mounting, and nominal pressure drop.

• Kobold’s model DUK ultrasonic flow meters were selected for different line sizes because of their high accuracy for measurement, compact size, and possibility of mounting in any direction. Tri-clamp coupling were used with the flow meters in order to accomplish quick and easy maintenance. Manual presetting valves and ball valves were incorporated for fi ne regulation and control.
• Kobold’s model TDA temperature indicator / transmitters were selected as they can be installed with a very small insertion length on the pipe lines without thermo-wells. They were installed in individual return lines to monitor and re-transmit the actual value to a remote location for recording purpose.
• Kobold’s model PDA pressure indicator / transmitters were used to measure the exact pressure in the chilling lines, fulfilling the requirement for high precision and accurate measurement.