Simulation of a data center cooling system in an emergency situation

The paper deals with keeping server rooms at reasonable air temperature in the case of an electrical power failure in a data center and with building performance simulations used to support emergency power planning. An existing data center was analyzed in detail with respect to the possibilities of emergency cooling. Based on the assumption that the thermal capacity of already chilled water can be used to prolong functionality of the cooling system when the roof chillers are out of operation, a backup power supply was designed for Computer Room Air-Conditioning and even for the cooling liquid circuit pumps (i.e. not for the roof chillers). Special models representing the data center indoor environment and cooling system, including a detailed model of the Computer Room Air Conditioning (CRAC) units, were developed in order to estimate the time period during which the internal air temperatures in the server room will not exceed the limit. The numerical model of the server room and the cooling system was built in the TRNSYS software and calibrated by measured data acquired from a real power outage situation. The results and conclusions obtained from the performed analyses and simulations helped to improve the emergency power plan of the data center. The study also forms the basis for the development of an emergency decision algorithm that will included in the novel supervisory control platform: GENi

Simulation-based assessment of thermal aware computation of a bespoke data centre

The role of Data Centres (DCs) as global electricity consumers is growing rapidly due to the exponential increase of computational demand that modern times require. Control strategies that minimize energy consumption while guaranteeing optimal operation conditions in DC are essential to achieve sustainable and energy efficient DCs. Unfortunately, the development and testing of novel control strategies are often slowed down, if not discarded. This is generally due to the lack of access caused by safety and economic reasons. Alternatively, simulation experiments represent a “safe” virtual environment to test novel control strategies, accelerating the process for their implementation in physical DCs. The virtual DC testbed, originated in the GENiC project, supports the development and dynamic testing of control and energy management algorithms. This paper introduces its features and describes its functionality through a simulation-based assessment of thermal aware computation strategy. For this, the virtual DC will be based on a bespoke DC located in Cork (Ireland). This DC has 30 kW capacity, 40 m2 floor area and its layout follows a hot aisle - cold aisle arrangement without containment. The performance the IT Workload allocation under different scenarios and their influence both on the whitespace environment and overall DC performance are evaluated and quantified. Finally, the benefits of a coordinated operation between the thermal and the IT workload managements are discussed

Implementation and demonstration of a building simulation based testbed for assessment of data centre multi-domain control strategies

The traditional data centre (DC) infrastructure is beingsignificantly extended by modern information technology(IT) trends on one side, and lasting calling for DCsustainability on the other. A holistic DC managementwill be necessary to coordinate different DC processesand to dock the DC environment into modern cities anddistrict infrastructure. A development of such a complexmanagement requires comprehensive testing possibilities.The testing is hardly possible on the real DC infrastructuredue to the mission critical nature. Building energymodelling methods offer a suitable platform for thedevelopment of a safe and reliable testing environment.This paper deals with new application of Building EnergySimulation (BES) method and introduces a workflow forvirtual closed-loop testing of enhanced multi-domainoperation for data centres<br/

Chapter Globally Optimised Energy-Efficient Data Centres

A great deal of energy in Information and Communication Technology (ICT) systems can be wasted by software, regardless of how energy-efficient the underlying hardware is. To avoid such waste, programmers need to understand the energy consumption of programs during the development process rather than waiting to measure energy after deployment. Such understanding is hindered by the large conceptual gap from hardware, where energy is consumed, to high-level languages and programming abstractions. The approaches described in this chapter involve two main topics: energy modelling and energy analysis. The purpose of modelling is to attribute energy values to programming constructs, whether at the level of machine instructions, intermediate code or source code. Energy analysis involves inferring the energy consumption of a program from the program semantics along with an energy model. Finally, the chapter discusses how energy analysis and modelling techniques can be incorporated in software engineering tools, including existing compilers, to assist the energy-aware programmer to optimise the energy consumption of code

Microbial diversity and biogeochemical cycling in soda lakes

Soda lakes contain high concentrations of sodium carbonates resulting in a stable elevated pH, which provide a unique habitat to a rich diversity of haloalkaliphilic bacteria and archaea. Both cultivation-dependent and -independent methods have aided the identification of key processes and genes in the microbially mediated carbon, nitrogen, and sulfur biogeochemical cycles in soda lakes. In order to survive in this extreme environment, haloalkaliphiles have developed various bioenergetic and structural adaptations to maintain pH homeostasis and intracellular osmotic pressure. The cultivation of a handful of strains has led to the isolation of a number of extremozymes, which allow the cell to perform enzymatic reactions at these extreme conditions. These enzymes potentially contribute to biotechnological applications. In addition, microbial species active in the sulfur cycle can be used for sulfur remediation purposes. Future research should combine both innovative culture methods and state-of-the-art ‘meta-omic’ techniques to gain a comprehensive understanding of the microbes that flourish in these extreme environments and the processes they mediate. Coupling the biogeochemical C, N, and S cycles and identifying where each process takes place on a spatial and temporal scale could unravel the interspecies relationships and thereby reveal more about the ecosystem dynamics of these enigmatic extreme environments

Simulation of a data center cooling system in an emergency situation

The paper deals with keeping server rooms at reasonable air temperature in the case of an electrical power failure in a data center and with building performance simulations used to support emergency power planning. An existing data center was analyzed in detail with respect to the possibilities of emergency cooling. Based on the assumption that the thermal capacity of already chilled water can be used to prolong functionality of the cooling system when the roof chillers are out of operation, a backup power supply was designed for Computer Room Air-Conditioning and even for the cooling liquid circuit pumps (i.e. not for the roof chillers). Special models representing the data center indoor environment and cooling system, including a detailed model of the Computer Room Air Conditioning (CRAC) units, were developed in order to estimate the time period during which the internal air temperatures in the server room will not exceed the limit. The numerical model of the server room and the cooling system was built in the TRNSYS software and calibrated by measured data acquired from a real power outage situation. The results and conclusions obtained from the performed analyses and simulations helped to improve the emergency power plan of the data center. The study also forms the basis for the development of an emergency decision algorithm that will included in the novel supervisory control platform: GENi

Simulace chladicího systému datacentra v havarijním stavu

The paper deals with the simula tion of indoor environment in a da ta center a t breakdown of its cooling sys - tem. Individual components of the cooling system during the breakdown were studied in detail with respect to their influence on the course of the emergency situation, in particular the influence of the cooling circuit thermal capacity. A complex numerical model was set up in TRNSYS simulation environment to predict energy flows and air temperatures in the data center. The simulation model describes in detail the cooling system including control elements and it takes into account heat accumulation in room constructions. The model represents a real data center and it was calibrated using data from a real emergency situation. The simulation results showed that the backup of water circuit makes possible to extend the operation time of the data center at emergency