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.
Experimental characterization of a Rear Door Heat exchanger with localized containment
In the current study, the thermal performance of a rear door heat exchanger is investigated experimentally. The experiments were conducted at the ES2 research data center lab at Binghamton University. A rear door heat exchanger was attached to an isolated equipment cabinet so that the operating conditions could be carefully controlled. On the water side of the heat exchanger, a control system provides for variation of the water flowrate by changing the pump speed. The water supply temperature is controllable by adjusting a three way valve that alters the mixture of fresh cold water with the heat exchanger return water. Both the water supply and return temperatures are monitored remotely. On the air side, a grid of 36 air velocity/temperature sensors installed on a portable frame enabled remote monitoring of the air stream properties. A combination of commercial servers and a 10kW server simulator were used to generate a controllable heat load. A single perforated tile with 65% openness delivers sufficient airflow from the raised floor plenum to the IT equipment. A localized containment system was added to the front of the cabinet in order to control the air inlet conditions to the equipment. The rear door heat exchanger was characterized for a range of different air and water flowrates along with different power generation levels. In addition, the impact of air leakage within the cabinet was studied in relation to the air flow provisioning level.
Fully Integrated Bidirectional CMOS-MEMS Flow Sensor With Low Power Pulse Operation
Leveraging More-than-Moore technology, we demonstrate an integrated CMOS MEMS flow sensor via a very compact system on chip (SoC) that can sense the bidirectional N2 gas flow. Our SoC features a very low-noise instrumentation amplifier that is implemented on a CMOS wafer and serves as a readout integrated circuit for a thermoresistive micro-calorimetric flow sensor which is fabricated on a MEMS wafer. A compact heterogeneous integration is achieved by combining the two wafers via the proprietary InvenSense AlN process. The measured sensitivity of our CMOS MEMS flow sensor is 98 mV/sccm which is three times better than the state-of-the-art counterpart. The flow range measured by our SoC is from −26 to 26 m/s (from −50 to 50 sccm). Moreover, the pulsed heater operation makes this proposed SoC flow sensor a very low power (<9 mW) and, thus, a promising candidate for the Internet-of-Things applications in smart home/green buildings.