Equation-based object-oriented modeling and simulation of data center cooling systems

Abstract

Cooling infrastructures contribute about 50% of total energy consumption in a typical data center. Computer models are pivotal in designing and optimizing energy-efficient cooling systems to reduce excessive cooling energy consumption. Compared to the conventional building energy simulation tools, equation-based object-oriented modeling language Modelica is an emerging approach that can enable fast modeling and simulation of the dynamic cooling system in data centers. In this paper, we introduce a newly developed open source data center package in the Modelica Buildings library to support the fast modeling and simulation of cooling and control systems of data centers. The data center package contains major thermal and control component models, such as Computer Room Air Handler, Computer Room Air Conditioner, models of different subsystem configurations such as chillers with differently configured waterside economizer, as well as templates for different systems. Furthermore, we utilize the new package to perform a case study on the operation of a cooling system in the data center. In this case study, we investigate the performances of the cooling system under normal conditions and emergency situations such as blackout. The case study shows that the dynamic modeling and multi-domain co-simulation in the Modelica-based tool make it convenient for users to investigate not only the thermal performance but also the electrical performance of the data centers.

Modelica-Based Modeling and Simulation of District Cooling Systems: A Case Study

“…We used models from the Buildings library version 7.0.0 [13] and the Modelica Standard library version 3.2.3 [29]. For DC systems in particular, the Data Center package of the Buildings library [25] provides many equipment and subsystem models for chiller plants with and without WSE. Further, AixLib [30], IDEAS [31], and Building Systems [32] are all open-source libraries suitable for DC system model development, in addition to the District Cooling Open Source Library [12] previously mentioned.…”

“…Second, we evaluate the control and energy performance of a chiller plant with a waterside economizer (WSE) connected to a district network. The WSE is a "free cooling" heat exchanger that is a popular and effective way to improve chiller service life and reduce plant energy consumption [23,24,25]. From a modeling standpoint, Modelica is particularly suited to capture the nonlinearities present in chiller plants with WSE [26], which is not always possible with other tools.…”

Optimal Scheduling of Cooling and Power Combined Supply System for Tropical Renewable Microgrids

“…A novel implementation strategy is formulated in [22] for mine cooling systems to improve the energy utilization. A newly developed open source data center package in the Modelica Buildings library is introduced in [23] to support modeling and simulation of cooling and control systems of data centers. Physics based models are developed in [24] to allow the prediction of the energy consumption and heat transfer phenomenon in a data center.…”

An optimization platform based on coupled indoor environment and HVAC simulation and its application in optimal thermostat placement

“…), and promising results in terms of whole-year-energy-consumption reductions were presented. Similarly, the optimization methodology based on single simulator has been applied to study the control performance of building energy systems in a dynamic fashion (Tian, Zhang, et al 2018;Chen et al 2018;Fu et al 2019;Afram et al 2017;D'Agostino and Parker 2018;Han et al 2013). For example, Huang et al (2016) and Huang et al (2017) applied the optimization based on the Modelica representation of the HVAC system to find the optimal set point of condensing water temperature and chiller staging control.…”