Energy Consumption of Chillers Reduced by 20.6%

Background

The air conditioning system at a government facility in Hong Kong is powered by one fresh water cooled chiller and one fresh water cooled heat recovery chiller which produce 260TR cooling capacity in total.

Commercial chemicals such as biocide, scale and corrosion inhibitor are used in the condensing water. Due to the limitation of chemicals and constraint of treatment program, mineral scale deposit and development of biofilm led to necessity of annual tube cleaning to restore the energy efficiency.

In order to improve the COP of the two chillers, Hydropath technology was installed by a local Hydropath distributor. The condenser tubes were inspected and the condition was recorded in Picture 1 before switching on the Hydropath technology. The tubes were then cleaned and anti-corrosion paint was reapplied (Picture 2).

Result

After one year of operation, the condenser cover was dismantled for tube inspection. The condition of condenser tubes and anti-corrosion paint was nearly the same (Picture 3) as just after cleaning.

The data logged by the existing BMS shows there is a reduction of 20.6% of energy consumption in the chiller plant.

The savings were relatively high due to the heat recovery chiller operated at high inefficiency, as the hot water was never used, which reduced the heat rejection capacity of the chiller. This condition was worsened by the formation of mineral scale and biofilm, which the Hydropath technology corrected, and significant cost savings were realized.

 
                    Day 1 - Condenser Tubes -Original Condition - Picture 1

                    Day 1 - Condenser Tubes -Original Condition - Picture 1

           Day 1 -   CONDENSER TUBES Cleaned and Repainted - PICTURE 2

           Day 1 -   CONDENSER TUBES Cleaned and Repainted - PICTURE 2

             CONDENSER TUBES - PICTURE 3 - One Year of HydroFlow Use

             CONDENSER TUBES - PICTURE 3 - One Year of HydroFlow Use