The B-number and soot yield are fundamentally robust parameters that may be used in the future as means to classify the flammability of a given warehouse commodity, to strengthen the level of confidence in determining the flammability of a commodity, and to increase the effectiveness of warehouse fire protection and suppression applications. Additionally, the results of this study are useful for the application of sprinkler activation and determining the amount of sprinkler suppression that is necessary as a fire grows larger.Electricity consumption projections place data centers at up to 13% of global electricity demand in 2030 due to the expected growth in the production and use of electronic devices, cloud services, and computer networks. Cooling infrastructure accounts for up to 40% of the total energy delivered to a data center. With business and society relying so much on data centers, there is a greater need for reliable and clean electric power for data centers. Solid Oxide Fuel Cell systems have the potential to provide more reliable and cleaner electrical load-following characteristics compared to other technologies while enabling dynamic operation and control. High temperature exhaust of SOFC can be used to run a bottoming cycle such as cooling system which makes it an attractive integrated system for data center applications. However, cost and durability are major challenges associated with SOFC technology. On the other hand, the biggest challenge for using hydrogen as an energy carrier for SOFC is the very high pressure or very low temperature required for its storage, transmission, and distribution,nft growing system which makes the need for a more dense liquid energy carrier like ammonia inevitable. This dissertation, first, focuses on evaluating the integrated system concept and assesses the achievable air conditioning from SOFC waste heat.
To explore the feasibility of thermally integrating SOFC with liquid desiccant dehumidification , a spatially resolved physical model developed in MATLAB is used to simulate the operating characteristics of this SOFC system. A corresponding physical model is developed to simulate the liquid desiccant air conditioner for dehumidification. This research evaluated SOFC systems for powering demand of a single server rack to powering a row of servers . The LDD operation is based on distributed waste heat from SOFC that powers the servers. This research indicates whether waste-heat based cooling and dehumidification could power the servers and maintain server operating temperatures and humidity in the safe range for different weather conditions. It calculated the yearly storage capacity required for each location to meet the demand of the data center for the entire year. Next, the performance and degradation of a 1.5kW commercial system, that is proposed for source of power and cooling of servers, is evaluated under steady state and dynamic load cycling conditions for over 6000 hours. The degradation rate and performance characteristics of the SOFC system is analyzed to determine the long-term performance and durability of SOFC system under dynamic condition. Finally, to analyze and compare the degradation of single cell SOFC directly fed with ammonia , externally reformed ammonia and pure hydrogen , three durability tests are conducted on anodesupported SOFC. Electrochemical impedance spectroscopy and scanning electron microscopy are conducted to study the performance losses during operation and to observe the microstructure changes of the cell after testing. The rapid growth of internet use, cloud computing and data-driven machines and services is increasing the electric power consumption and carbon footprint of data centers. Data center electricity demand was around 200TWh in 2018.However, due to the expected growth in the production and use of electronic devices, cloud services, and computer networks, electricity consumption projections place data centers at up to 13% of global electricity demand in 2030.
As shown in Figure 1 in the best-case scenario data center electricity consumption doubles in the next 10 years. Associated with this massive electricity consumption are greenhouse gas and criteria pollutant emissions due to the use of conventional fossil energy resources to power data center electric loads. In 2020, the information and communications technology sector represented 2.3% of global GHG emissions, 28.8% of which were associated with data centers. In addition, as a result of the COVID-19 pandemic, dependency upon internet technology, and cloud services, data center demands are only increased further. Data centers will use around 3–13% of global electricity in 2030 compared to 1% in 2010. In order to meet the emissions reduction targets imposed by many IT companies like Microsoft, the power supply for data centers must come from renewable energy sources. The trend of using renewable power is being used widely and likely many data centers can be run with low GHG and pollutant emissions, even if they do not find ways to reduce their absolute electricity usage.In a traditional data center connected to the electric grid, less than 35% of the energy from the fuel source that is supplied to the power plant is delivered to the data center. Power plant generation losses and transmission and distribution losses are the most significant inefficiencies in data center. Figure 2 shows the process of power loss through the transportation and distribution network of the electric grid starting from the fuel source up to the power supplied to the consumer. It is evident that the largest inefficiency is from the power generated at the power plant level with additional losses associated with the transmission and distribution to the data center, where the data center receives roughly 30% of the total energy that could have been supplied ideally from the fuel source. There are further losses associated with the infrastructure required for daily reliable operation systems. The additional power consumed by the cooling, lighting, and energy storage, means approximately less than 17.5% of the energy supplied to the power plant is ultimately delivered to the servers. Information Technology equipment and cooling infrastructure are the two major power consumers. As shown in Figure 3 cooling infrastructure is a large electricity consumer in the data center and can account for up to 40% of the total energy delivered to the data center. Cooling also represents the biggest slice of the total cost in a data center.
With more capacity and higher density there is an increased need for energy-efficient cooling of the IT equipment. While data centers need cooling to protect servers and other equipment, an additional challenge is humidity control. Too much humidity can cause corrosion of metal parts of the servers leading to short circuiting of electronics. On the other hand, low humidity allows the servers to develop electrostatic charges that can cause damage to sensitive equipment. According to Uptime Institute, electric power outages are the main causes of the increasing outage trend in data centers. According to the Eaton Blackout Tracker, the US experienced more than 3,500 utility power outages in 2017, the vast majority of which were attributed to faults in the transmission and distribution system. This number represents a 62% increase in outages from a decade ago. In 2018, a storm interrupted grid power to Microsoft’s San Antonio Azure data center, knocking cooling systems offline, damaging a significant amount of equipment, and bringing down Active Directory and Visual Studio Team Services for almost 24 hour. In some areas, rising temperatures are driving up the cost of data centers. In other areas, extreme rainfall and flooding have damaged equipment, and prevented the fuel deliveries which are so critical to the traditional back-up power solutions. And power costs continuously increase. The global cost of power for data centers is expected to increase 80% in the next five years. At 35% of total costs,vertical hydroponic nft system electric power continues to represent the largest portion of data center operating costs. Every power generation system that supplies a data center must comply with stringent reliability and availability constraints to ensure 99.9999% server uptime. With business and society relying so much on data centers, and data centers growing more and more, there is a greater need for reliable and clean electric power for data centers. Our solution is using small scale Solid Oxide Fuel Cell for rack level power generation, which is capable of delivering uninterrupted, 24×7 power that is resilient and clean and eliminates the need for back up generation and is also able to provide high quality heat to run a liquid desiccant dehumidification system to provide cooled and dehumidified air for servers. Generating power on-site, at the point of consumption, rather than centrally, eliminate the cost, complexity, interdependencies, and inefficiencies associated with electrical transmission and distribution. Providing the required cooling for servers through liquid desiccant dehumidification run by high quality exhaust of SOFC has the potential to decrease the power consumption of data centers by up to 40%.In this research, first, I investigate the integration of rack level fuel cell powered servers with Liquid Desiccant Dehumidifier technology that can be dynamically dispatched to produce electricity and cooling in various amounts to meet power and air conditioning demands of data centers. This thesis focusses first on evaluating the integrated system concept and to assess the achievable air conditioning from SOFC waste heat. To explore the feasibility of thermally integrating SOFC with LDD, a spatially resolved physical model developed in Matlab is used to simulate the operating characteristics of this SOFC system.
A corresponding physical model is developed to simulate the liquid desiccant air conditioner for dehumidification. This study considers SOFC systems capable of powering a 1. single server rack and the operation of an LDD for cooling and dehumidification of that same rack, and 2. SOFC and LDD systems designed for a row of 20 servers. The analysis will indicate whether waste-heat based cooling and dehumidification is capable of powering the servers and maintaining server operating temperatures and humidity in the safe range for different weather conditions. Even though SOFC technology offers several advantages such as fuel flexibility, high efficiency, and zero criteria pollutant emissions, cost and durability are major challenges associated with current SOFC technology. Durability of SOFC technology is a key aspect for its commercialization and long-lasting deployment in different applications. Dynamic operating conditions have considerable effects on the long-term performance and durability of SOFC systems. On the other hand, while many studies have focused on green hydrogen produced through electrolysis from sun and wind, as a clean fuel for fuel cells, the biggest challenge for using hydrogen as an energy carrier is the very high pressure or very low temperature required for its storage, transmission and distribution, which makes the need for a more dense liquid energy carrier like ammonia inevitable. I propose that ammonia made in a sustainable way can serve as a sustainable, low-cost, and high-density energy carrier and the fuel for SOFC systems in the Future.In the second part of this research, I first evaluate the performance and degradation of a 1.5kW Alternating Current commercial SOFC system that is proposed for source of power and cooling of servers under steady state and dynamic load cycling conditions for over 6000 hours. I monitored and analyzed the degradation rate and performance characteristics of the SOFC system to determine the long-term performance and durability of SOFC system under dynamic operating conditions. Second, I evaluate the effect of ammonia as fuel on SOFC performance. I study and compare the degradation of an SOFC single cell fed with fed with ammonia , externally reformed ammonia and pure hydrogen . The goal of this thesis in to evaluate the integration of SOFC with Liquid Desiccant Air Conditioning for efficient, reliable, and grid-independent data center power and cooling. The integrated system will supply electricity and cooling to data center applications. This configuration offers the potential for high energy efficiency, environmental and economic benefits. The integrated concept is shown in Figure 4. The SOFC generates electricity from natural gas which is used directly for powering a rack of servers. The SOFC thermal exhaust will be used to produce hot water which is used for regenerating the liquid desiccant. Concentrated liquid desiccant will be stored and is used for dehumidifying the air when there is a cooling demand. The integrated system is expected to have high efficiency, low emission and provide reliable power and cooling for data center applications. This integrated configuration eliminates grid connection and any transmission line for powering servers as well as significantly decreasing the electric power used for providing cooling to servers.Most traditional data centers get their primary electricity from utility electric grid.