Guidelines and Experimental Hydraulic Performance Evaluation for Single-Phase CDUs Under Steady and Transient Events (ITherm 2023)

Overview

This study by Ali Heydari for IEEE ITherm 2023 (22nd Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems) tests liquid-to-air and liquid-to-liquid coolant distribution units (CDUs) on multi-rack setups loaded with thermal test vehicles (TTVs). The record rests only on the abstract; the full text was not read. As motivation, it points to the inefficiency of raised-floor air delivery at high density, and the abstract cites cooling as about 40% of data-centre energy use.

The method has two parts. The first is measuring hydro-thermal performance under different secondary-coolant conditions. The second is examining transient behaviour: TTV cooling loops were disconnected and reconnected in different sequences to observe system response. Both liquid-to-air and liquid-to-liquid CDUs were evaluated on multiple racks with varying numbers of thermal test vehicles. This experimental set-up aims to show how a CDU responds to sudden changes in flow and pressure.

The stated outcome of the study is a set of rules and guidelines for commissioning single-phase CDUs. As a limit, this is only an abstract-level record; measurement results, pressures and flow values are not included. Even so, it conveys the message that transient events, meaning loop disconnection and reconnection, should be an integral part of commissioning tests.

Key points

1. Both liquid-to-air and liquid-to-liquid CDUs were evaluated on multiple racks with varying numbers of thermal test vehicles.
2. Transient events were created by disconnecting and reconnecting TTV loops in different sequences to observe system response.
3. The study aims to establish rules and guidelines for commissioning single-phase CDUs.
4. The abstract cites cooling as about 40% of data-centre energy use as motivation.
5. Hydro-thermal performance was measured under different secondary-coolant conditions.

Using it in design

• Include loop connect/disconnect transient tests in commissioning scripts generated for liquid-cooled rows.
• Record CDU response (flow, differential pressure) as acceptance criteria.
• Include different disconnection and reconnection sequences in the commissioning test plan.

Who should read it

Engineers responsible for commissioning liquid-cooled rows and CDU manufacturers.

Related standards

• ASHRAE Liquid Cooling Guidelines

Publication details

Authors

Ali Heydari

Publisher

IEEE

Year

2023

Document number

DOI 10.1109/ITherm55368.2023.10177633

Event

IEEE ITherm 2023 (22nd Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems)

Document language

English

Source type

Standard

Access

Citation only

Licence

Copyright retained; citation only — the publisher’s terms apply to the original document

Citation