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At least 1,657 records · Page 92

Water Efficient Energy Production for Geothermal Resources

Water consumption in geothermal energy development occurs at several stages along the life cycle of the plant, during construction of the wells, piping, and plant; during hydroshearing and testing of the reservoir (for EGS); and during operation of the plant. These stages are highlighted in the illustration above. For more information about actual water use during these stages, please see the back of this sheet..

water, geothermal, energy, renewable↗

New Path for Building Compliance in ASHRAE Model Energy Efficiency Standard

This article describes a new path for performance based compliance with ASHRAE Standard 90.1. Using Appendix G, the Performance Rating Method, this path allows the same simulated baseline model to be used for both code compliance and beyond code programs. The baseline is fixed at approximately 90.1-2004 and independent of the designer's chosen design solutions to the greatest extent possible

Addendum BM↗

Stochastic Modeling of Short-term Occupancy for Energy Efficient Buildings

In this paper, we present a simple yet effective algorithm to automatically assign reference temperature set-points based on the occupancy information. Both the binary and detailed occupancy estimation cases are considered. In the first case study, we assume the schedule involves only binary states (occupied or not occupied), i.e. the room is invariant. With long-term observations occupancy levels can be estimated using statistical tools. In the second case study, two techniques are introduced. Firstly, we propose an identification-based approaches. More precisely, we identify the models via Expectation Maximization (EM) approach. The statistical state space model is built in linear form for the mapping between the occupancy measurements and real occupancy states with noise considered. Secondly, we introduce a novel finite state automata (FSA) which is successfully reconstructed by general systems problem solver (GSPS). As far as we know, no studies have used the finite state machine or general system theory to estimate occupancy in buildings. All above estimates can be used to adaptively update the temperature set-points for Heating, Ventilation, and Air-Conditioning (HVAC) control strategy.

Djouadi, Seddik M↗

Micro-Encapsulation of non-aqueous solvents for energy-efficient carbon capture

Here, we demonstrate micro-encapsulation of several promising designer solvents: an IL, PCIL, and CO2BOL. We develop custom polymers that cure by UV light in the presence of each solvent while maintaining high CO2 permeability. We use several new process strategies to accommodate the viscosity and phase changes. We then measure and compare the CO2 absorption rate and capacity as well as the multi-cycle performance of the encapsulated solvents. These results are compared with previous work on encapsulated sodium carbonate solution. The prospects for designer solvents to reduce the cost of post-combustion capture and the implications for process design with encapsulated solvents are discussed.

54 ENVIRONMENTAL SCIENCES↗

Energy efficient data center liquid cooling with geothermal enhancement

A data center cooling system is operated in a first mode, and has an indoor portion wherein heat is absorbed from components in the data center by a heat transfer fluid, and an outdoor heat exchanger portion and a geothermal heat exchanger portion. The first mode includes ambient air cooling of the heat transfer fluid in the outdoor heat exchanger portion and/or geothermal cooling of the heat transfer fluid in the geothermal heat exchanger portion. Based on an appropriate metric, a determination is made that a switch should be made from the first mode to a second mode; and, in response, the data center cooling system is switched to the second mode. The second mode is different than the first mode.

42 ENGINEERING↗