Heating, Ventilation, and Air Conditioning (HVAC) accounts for about half of the energy consumption in buildings. HVAC energy consumption can be reduced by changing the indoor air temperature setpoint, but changing the setpoint too aggressively can overly reduce user comfort. We have therefore designed and implemented SPOT: a Smart Per- sonalized O ce Thermal control system that balances energy conservation with personal thermal comfort in an o ce environment. SPOT relies on a new model for personal ther- mal comfort that we call the Predicted Personal Vote model. This model quantitatively predicts human comfort based on a set of underlying measurable environmental and per- sonal parameters. SPOT uses a set of sensors, including a Microsoft Kinect, to measure the parameters underlying the PPV model, then controls heating and cooling elements to dynamically adjust indoor temperature to maintain comfort. Based on a deployment of SPOT in a real o ce environment, we nd that SPOT can accurately maintain per- sonal comfort despite environmental uctuations and allows a worker to balance personal comfort with energy use.

Heating, Ventilation, and Air Conditioning (HVAC) accounts for about half of the energy consumption in buildings. HVAC energy consumption can be reduced by changing the indoor air temperature setpoint, but changing the setpoint too aggressively can overly reduce user comfort. We have therefore designed and implemented SPOT: a Smart Per- sonalized O ce Thermal control system that balances energy conservation with personal thermal comfort in an o ce environment. SPOT relies on a new model for personal ther- mal comfort that we call the Predicted Personal Vote model. This model quantitatively predicts human comfort based on a set of underlying measurable environmental and per- sonal parameters. SPOT uses a set of sensors, including a Microsoft Kinect, to measure the parameters underlying the PPV model, then controls heating and cooling elements to dynamically adjust indoor temperature to maintain comfort. Based on a deployment of SPOT in a real o ce environment, we nd that SPOT can accurately maintain per- sonal comfort despite environmental uctuations and allows a worker to balance personal comfort with energy use.

This thesis investigated a potential improvement to hydrogen storage for fuel cells using a thermally efficient hydrogen storage method. The efficiency of the storage system was improved using a metal hydride system to act as a thermal control unit for an exothermic chemical hydrogen storage system. A cylindrical shaped “hybrid” reactor was created to allow hydrogen production from a sodium borohydride packed bed reactor and the metal hydride. Additionally, a custom built pressure-composition-temperature apparatus was built to record the amount of hydrogen desorption from the metal hydride while isolating the metal from potential poisons such as oxygen. Before using the chemical hydride packed bed, heat transfer through the reactor was studied using circulating water. The water experiments showed that an increase in heat flux to the reactor led to a faster desorption rate of hydrogen from the metal hydride resulting in a larger temperature drop throughout the reactor. After the operating characteristics of the hybrid reactor were studied, a 10 wt% solution of sodium borohydride was created and pumped through the packed bed to produce enough hydrogen for a 300 W fuel cell. The amount of heat produced from the packed bed portion of the reactor was significant, but temperatures levelled to around 80 °C. As expected, temperature control was directly proportional to the rate of hydrogen release from the metal hydride. On average, approximately 10% of the available heat energy was transferred to the metal hydride, and the hybrid reactor operated with gravimetric and volumetric energy densities of 0.27 kWh·kg-1 and 1.29 kWh·L-1 respectively. If the hybrid reactor is used solely to control peak temperatures, the amount of metal hydride necessary for thermal control could be decreased. Additionally, improvements in heat transfer as well as the hydrogen storage materials themselves would increase the energy density values further. When compared to other energy storage devices, the hybrid reactor without improvements is competitive as a backup power generator due to its silent operation and large volumetric energy density. Since the hybrid reactor can provide quiet and cool energy storage in a relatively small volume, it may become an effective and efficient means for hydrogen storage with limited improvements. / Thesis (Master, Mining Engineering) -- Queen's University, 2007-12-06 14:45:56.551 / AUTO21

Research has been completed in order to rapidly manufacture spacecraft thermal control technologies embedded in spacecraft structural panels using ultrasonic consolidation. This rapid manufacturing process enables custom thermal control designs in the time frame necessary for responsive space. Successfully embedded components include temperature sensors, heaters, wire harnessing, pre-manufactured heat pipes, and custom integral heat pipes. High conductivity inserts and custom integral pulsating heat pipes were unsuccessfully attempted. This research shows the viability of rapid manufacturing of spacecraft structures with embedded thermal control using ultrasonic consolidation.

This study investigates the software automation and control framework for the MMT thermal system. Thermal-related effects on observing and telescope behavior have been considered during the entire software development process. Regression analysis of telescope and observatory subsystem data is used to characterize and model these thermal-related effects. The regression models help predict expected changes in focus and overall astronomical seeing that result from temperature variations within the telescope structure, within the primary mirror glass, and between the primary mirror glass and adjacent air (i.e., mirror seeing). This discussion is followed by a description of ongoing upgrades to the heating, ventilation and air conditioning (HVAC) system and the associated software controls. The improvements of the MMT thermal system have two objectives: 1) to provide air conditioning capabilities for the MMT facilities, and 2) to modernize and enhance the primary mirror (M1) ventilation system. The HVAC upgrade necessitates changes to the automation and control of the M1 ventilation system. The revised control system must factor in the additional requirements of the HVAC system, while still optimizing performance of the M1 ventilation system and the M1's optical behavior. An industry-standard HVAC communication and networking protocol, BACnet (Building Automation and Control network), has been adopted. Integration of the BACnet protocol into the existing software framework at the MMT is discussed. Performance of the existing automated system is evaluated and a preliminary upgraded automated control system is presented. Finally, user interfaces to the new HVAC system are discussed.

Contributions to two missions are presented. The first is a demonstration mission called CanX-7 that uses a 4 square metre drag sail to de-orbit a 3.5 kg satellite. In order to estimate the effectiveness of the drag sail, a novel method is developed that takes into account the time-varying nature of the projected drag area. The Space Flight Laboratory designed drag sail is shown to be sufficient to de-orbit the CanX-7 spacecraft within the 25 year requirement. The Antarctic Broadband demonstrator spacecraft is a 20 cm cubical nanosatellite that will demonstrate the feasibility of a Ka-band link between the research community in Antarctica and stakeholders in Australia. In support of this mission, a passive thermal control subsystem is designed that will keep all the components within their operational temperature limits at all times throughout the mission.

Contributions to two missions are presented. The first is a demonstration mission called CanX-7 that uses a 4 square metre drag sail to de-orbit a 3.5 kg satellite. In order to estimate the effectiveness of the drag sail, a novel method is developed that takes into account the time-varying nature of the projected drag area. The Space Flight Laboratory designed drag sail is shown to be sufficient to de-orbit the CanX-7 spacecraft within the 25 year requirement. The Antarctic Broadband demonstrator spacecraft is a 20 cm cubical nanosatellite that will demonstrate the feasibility of a Ka-band link between the research community in Antarctica and stakeholders in Australia. In support of this mission, a passive thermal control subsystem is designed that will keep all the components within their operational temperature limits at all times throughout the mission.

No description available.

Lic.-avh. SLU : Sveriges lantbruksuniv., 2009. / Härtill 2 uppsatser.

The increased penetration of residential-scale photovoltaic (PV) systems in European-style low voltage (LV) networks (i.e., long feeders with high number of connected customers) is leading to technical issues such as voltage rise and thermal overload of the most expensive network assets (i.e., transformer, cables). As these issues significantly limit the ability of LV networks to accommodate higher PV penetrations, Distribution Network Operators (DNOs) are required to proceed with expensive and time-consuming investments in order to reinforce or replace these assets. In contrast to this traditional approach of network reinforcement, which potentially leads to massive capital expenditure, the transition towards active LV networks where controllable elements, existing (i.e., PV systems) and likely to be adopted (i.e., battery energy storage systems, LV on-load tap changer transformers), can be managed in real-time, poses an attractive alternative. Although several active network management schemes have been recently proposed to increase the hosting capacity of PV-rich LV networks, they are mostly based on managing voltage issues only; and, in general, aim to solve technical issues separately. Integrated solutions aiming at managing simultaneously voltage and thermal issues are required, as recent studies demonstrate that both issues can coexist in PV-rich LV networks. More importantly the majority of studies, which commonly neglect the characteristics of real LV networks (e.g., unbalanced, three-phase, radial, multiple feeders with several branches, different types of customers), use complex optimisation techniques that require expensive communication infrastructure and extensive or full network observability (currently not available in LV networks). However, considering the extensiveness of LV networks around the world, practical, cost-effective and scalable solutions that use limited and already available information are more likely to be adopted by the industry. Considering the above gaps in the literature, this Thesis contributes by proposing innovative and scalable active network management schemes that use limited network monitoring and communication infrastructure to actively manage (1) Residential-scale PV systems, (2) Residential-scale Battery Energy Storage (BES) systems and (3) LV on-load tap changer (OLTC)-fitted transformers. The adoption of the proposed active network management schemes, which makes use of already available devices, information and requires limited monitoring (i.e., secondary distribution substation), allows making the transition towards active LV networks more practical and cost-effective. In addition, to tackle the challenges related to this research (i.e., lack of realistic LV network modelling with high resolution time-series analyses), this Thesis, being part of the industrial project 'Active Management of LV Networks' (funded by EDF R&D) and having access to French data, contributes by considering a fully modelled typical real residential French LV network (three-phase four-wire) with different characteristics and number of customers. Moreover, realistic (1-min resolution) daily time-series household (from real smart meter data) and PV generation profiles are considered while a stochastic approach (i.e., Monte Carlo) is adopted to cater for the uncertainties related to household demand as well as PV generation and location.