Evaluation of Hybrid Cooling Technologies for AI Data Centers and AI-Based Sustainability Optimization Modeling
AI 데이터센터의 하이브리드 냉각 기술 평가 및 AI 기반 지속가능성(Sustainability)최적화 모델링 연구
Recent advances in Generative Artificial Intelligence (Generative AI) and Large Language Models (LLMs) have significantly increased the power consumption and heat generation of AI data centers, highlighting the growing importance of cooling technologies for high-density computing environments. This study reviews four major cooling technologies for AI data centers—air cooling, Rear Door Heat Exchanger (RDHx), Direct-to-Chip (D2C) liquid cooling, and immersion cooling—through a literature-based comparative analysis and proposes a suitable cooling strategy from a sustainability perspective. The performance of each cooling technology was evaluated using Power Usage Effectiveness (PUE), Water Usage Effectiveness (WUE), and Carbon Usage Effectiveness (CUE). Based on representative reference values synthesized from the literature and technical sources, the proposed D2C-based hybrid cooling architecture showed approximately 25% lower PUE and 40% lower CUE than conventional air cooling, indicating a balanced solution in terms of cooling performance, energy efficiency, and compatibility with existing infrastructure. In addition, the integration of waste heat recovery and AI-based predictive control was proposed to improve energy utilization and operational efficiency. Furthermore, this study proposes a conceptual cooling– workload co-optimization model that incorporates time-varying grid carbon intensity and regional water-stress indicators, extending conventional static PUE/WUE/CUE-based evaluation toward dynamic sustainability-oriented operation. The proposed framework jointly considers cooling operation and schedulable AI workloads to account for the trade-off between carbon emissions and water consumption under varying operating conditions. This integrated framework represents the principal contribution of this study and provides a basis for developing more sustainable cooling and workload management strategies for next-generation AI data centers.
한국어
최근 생성형 인공지능(Generative AI)과 대규모 언어모델(Large Language Model)의 확산으로 AI 데이터센터의 전력 소비와 발열량이 급격히 증가하고 있으며, 이에 따라 고밀도 컴퓨팅 환경에 적합한 냉각 기술의 중요성이 높아지고 있다. 본 연구는 AI데이터센터에 적용되는 공랭식(Air Cooling), 후면도어 열교환기(Rear Door Heat Exchanger, RDHx), 직접수냉식(Direct-to-Chip, D2C), 액침냉각(Immersion Cooling) 기술을 문헌 기반 비교분석을 통해 검토하고, 지속가능성 관점에서 적합한 냉각 전략을 제안하였다. PUE, WUE 및 CUE 지표를 활용하여 각 냉각기술의 성능을 비교·평가하였으며, 문헌 및 기술자료를 통해 종합한 대표 참고값을 기준으로 D2C 기반 하이브리드 냉각 구조는 공랭식 대비 PUE 약 25%, CUE 약 40% 낮은 값을 보여 냉각성능, 에너지 효율 및 기존 인프라 적용성 측면에서 균형적인 대안으로 평가되었다. 또한 폐열회수 시스템과 AI 기반 예측제어 기술을 결합함으로써 에너지 이용 효율과 운영 효율을 향상시킬 수 있는 방안을 제시하였다. 나아가 본 연구는 기존의 정적 PUE·WUE·CUE 기반 비교평가를 확장하여 실시간 탄소집약도와 지역별 물스트레스 지수를 고려한 냉각-워크로드 공동최적화 개념 모델을 제안하였다. 이를 통해 전력계통의 탄소배출 특성과 수자원 조건을 동시에 고려하여 냉각운영과 스케줄링 가능한 AI 워크로드를 공동 제어하는 지속가능한 운영방안을 제시하였다는 점에서 기존 냉각기술 비교 연구와 차별성을 갖는다.
목차
Abstract 요약 1. Introduction 1.1 Research Background 1.2 Research Objectives 2. Theoretical Background 2.1 High Heat Generation Characteristics of AI Data Centers 2.2 Classification of Cooling Technologies 2.3 Sustainability Evaluation Metrics 2.4 Review of Previous Studies 3. Research Methodology 3.1 Research Framework 3.2 Evaluation Metrics 4. Results and Discussion 4.1 Performance Comparison of Cooling Technologies 4.2 Analysis of Rear Door Heat Exchanger(RDHx) 4.3 Analysis of Direct-to-Chip (D2C) Cooling 4.4 Analysis of Immersion Cooling 5. Proposed Hybrid Cooling Model 5.1 D2C-Based Hybrid Cooling Architecture 5.2 Waste Heat Recovery System 5.3 AI-Based Predictive Control 5.4 Real-Time Carbon Intensity and Water Stress-Aware Cooling–Workload Co-Optimization Model 5.5 Validation Methodology for the Proposed Models (Future Experimental Design) 6. Conclusion REFERENCES