Management and predictions of operational changes and growth in mission critical facilities
The main challenge in understanding the cooling performance in a legacy data center is the invisible transport medium (air). This emphasizes the need for smart and meticulous measurement techniques. However, the nature of measurements is finite (e.g. top, middle and bottom) and the variation between often non-linear, therefore to capture the gradients between measured points a validated CFD simulation is needed. In this paper a brief description of an experimental characterization of a new data center lab is discussed. Airflow and temperature measurements are utilized to understand the facility's performance at different operational stages, until reaching the designed capacity. Since the facility houses a wide range of different IT equipment (servers, switches, storage and blades), it is important to understand the airflow demand of each. To do that, each type of IT was tested separately and flow characteristics were obtained (i.e. free delivery, critical pressure and flow curves). In the second part, all the characterization data is integrated via compact models into a full CFD simulation. The measured points are used for validation and the full field of air temperature and flow is resolved. Both the measurements and simulation data will now be used to answer important design, deployment and operational change questions.
Empirical analysis of blower cooling failure in containment: Effects on IT performance
Data Centers are prone to power outages and cooling failures. During such events, complex transport interactions take place between the cooling system and the IT. Empirical data on this phenomenon is scarce in the current literature due to the complexity and size of such experiments. In this study, a facility level data center blowers cooling failure experiment is run and analyzed. Quantitative instrumentation includes pressure differentials, tile airflow, point air inlet temperature, contours air inlet temperature and IT IPMI data during failure-recovery. Qualitative measurements include IR imaging and airflow visualization via smoke trace. To our knowledge, this is the first experimental study in literature in which an actual multi aisle facility cooling failure is run with real IT (compute, Network and storage) load in the white space. This will enable a link between variations from the facility to the chip levels. Results show that by using external air inlet temperature sensors the containment configuration has a longer uptime during failure. However, the IPMI data shows the opposite. In fact, the RTT is reduced by ~70% when the external and internal sensors are compared. This occurs due external impedances formed by the containment during failure degrading IT airflow systems. The inconsistency between IT IPMI inlet sensors and externally placed IT or rack inlet sensors (based on best practices) are expected to increase as the airflow imbalances increase.
Copper Phthalocyanine Improving Nonaqueous Catalysis of Pseudomonas cepacia Lipase for Ester Synthesis
The nonaqueous catalysis of lipases is significant for synthesis of high pure esters, but they usually behave low catalytic activity due to denaturation and aggregation of enzyme protein in organic phases. To improve the nonaqueous catalysis, the inexpensive copper phthalocyanine was taken as a new carrier on which Pseudomonas cepacia lipase was immobilized by physical absorption, and used for synthesis of hexyl acetate, an important flavor, via transesterification of hexanol and vinyl acetate. Results showed that the desired loading was 10 mg lipase immobilized on 10 mg copper phthalocyanine powder. When the immobilized lipase was employed in the reaction system consisted of 1.5 mL hexanol and 1.5 mL vinyl acetate at 37℃ and 160 rpm, the conversion was five fold of that catalyzed by native lipase after 1 h, and reached 99.0% after 8 h. Undergoing six times of 8-h reuses, the immobilized lipase had an activity attenuation rate 1.22% h− 1, lower than 1.77% h− 1 of native lipase, which meant that the immobilized lipase was more stable. Even at the room temperature and the static state without shaking or stirring, the immobilized lipase could bring conversion 42.8% after 10 h and the native lipase gave 20.1%. Obviously, the immobilized lipase is an available biocatalyst in organic phase and has great potential in food industry.