Lumine Shinjuku of Lumine Co., Ltd. is committed to continuously reducing the use of electricity and gas according to the Lumine Group’s environmental policies. The Kurita Group proposed to Lumine Shinjuku a method to curb the use of gas by maintaining the performance of its water chiller-heater. Specifically, performance is maintained by identifying the level of stains attached to the heat transmission surface of the heat exchanger located inside the water chiller-heater through the LTD values and then appropriately removing the attached stains with the use of water treatment chemicals.
The water chiller-heater is designed to supply cold water at a fixed temperature, and to maintain this temperature, the equipment will use a larger amount of fuel if the stains attached to the surface of the heat exchanger lower its thermal efficiency. The attachment of stains therefore results in energy loss compared to when the equipment is kept clean. To prevent energy loss and conserve energy, the Kurita Group proposed that the customer check for the attachment of stains at an early stage by measuring the LTD values, which serve as an indicator to show the thermal efficiency of the water chiller-heater.
In implementing the proposal for the customer, we made it possible (1) for the chemicals used to prevent the attachment of stains to be automatically poured into the cooling water according to the operational load of the cooling tower, and (2) for the stain removal chemicals to be additionally injected when the LTD value rose, thereby always keeping the heat exchanger in a clean state. This has brought about an annual reduction of 56 tons of CO2 emissions to the customer.

LTD meter (as shown by the arrow mark) installed to the chiller