ESL laboratory​

◇ Research Background

With the advent of the Fourth Industrial Revolution, the growth of domestic information and communication technologies such as IoT, artificial intelligence, and big data has led to a rapid increase in data demand, which in turn has expanded the scale of data centers. Major overseas IT companies are focusing their data center–related technology development on building environmentally friendly data centers and improving internal systems to provide data center services efficiently. They are leading the construction of green data centers by utilizing heating and cooling systems based on waste heat.
In the future, if waste heat from data centers can be actively utilized, it will provide significant environmental and economic benefits.
 

◇Research Method

To calculate the waste heat from domestic data centers, it is first necessary to clearly define the concept of waste heat.

The potential waste heat of a data center is defined as the measured amount of heat generated relative to the energy input, either from the cooling energy supplied to maintain the thermal environment inside the data center or from heat-generating equipment. Based on this definition, the information required to estimate the potential waste heat was derived.

The key data needed to calculate data center waste heat are:

• PUE (Power Usage Effectiveness)

• Total power consumption

• Inlet and outlet temperatures of chilled water in the cooling storage tank

• Flow rate of chilled water returning to the storage tank

• Cooling chiller specifications

• Number of chillers

• Power consumption of the chillers

• Operating hours of the chillers

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[Case 1] When PUE and IT power consumption are given
◎ Formula:
        Data center waste heat = (PUE × IT power consumption) − IT power consumption

[Case 2] When chilled water inlet/outlet temperatures and chilled water flow rate in the data center are given
◎ Formula:
        Data center waste heat (calculated using chilled water inlet/outlet temperatures and flow rate)  

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[Case 3] When chiller specifications and operating hours are given
◎ Formula:
        Data center waste heat = chiller capacity (kW) × operating time (h) × number of chillers

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Accordingly, a survey was conducted to obtain information from each data center, and the collected data were substituted into the above formulas to estimate the potential waste heat.