Browsing by Author "Trautman, Neal"

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    Overall Chilled Water System Energy Consumption Modeling and Optimization
    (Elsevier, 2021-10) Trautman, Neal; Razban, Ali; Chen, Jie; Mechanical and Energy Engineering, School of Engineering and Technology
    The emergence of increasingly affordable variable-speed drive technology has changed the approach used to control chilled water systems equipped with these drives. The purpose of this research was to develop an integrated chilled water modeling technique that can determine the optimal system setpoints and estimate the energy saving potential of chiller system. The chiller system equipped with Variable Frequency Drives (VFDs) on cooling tower fans and condenser water pumps. To accomplish the objective, physical component models of the centrifugal chiller, cooling tower and condenser water pump were established with the goal of incorporating the system’s condenser water flow rate and cooling tower fan speeds as optimization variables. Furthermore, a cooling load prediction algorithm was developed using a multiple non-linear regression model to approximate the building’s cooling load subject to a range of environmental conditions. The inputs and outputs of the individual component models were linked to estimate how adjusting the cooling tower fan and condenser water pump speed would influence the system’s comprehensive performance. The overall system model was then optimized using a generalized reduced gradient optimization algorithm to determine the potential energy savings through speed control with VFDs and to ascertain a control logic strategy for the building automation system to operate the heating and cooling system. A case-study was performed on a single chiller system at a museum and the model was calibrated according to logged data collected over four months. Results showed that for the system analyzed, the energy saving of optimizing the cooling tower fan system was found to be 12–15%, while the energy saving potential of optimizing the condenser water pump with the cooling tower fan was negligible. Additionally, comparing different cooling tower fan control strategies showed that a wet-bulb approach-based cooling tower control strategy was shown to have the highest correlation to the optimized fan speed with an R2 of 0.924.
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    Systematic energy and exergy efficiency study and comparison between direct fired and indirect fired heating systems
    (ECOS, 2019-06) Asl, Babak Bahrami; Trautman, Neal; Razban, Ali; Mechanical and Energy Engineering, School of Engineering and Technology
    The variability in energy demand provides one of the greatest challenges utilities face in supporting the electrical grid. Utilities meet peak demand loads through more expensive generation methods and as a result, utilities will often charge large energy users based on their peak electrical demand as well as their overall energy consumption. The peak demand charge incurred can represent a signi cant portion of the total utility bill, thus taking measures to manage electrical demand can result in substantial cost savings. The goal of this research is to analyze the potential bene ts of utilizing a small-scale compressed air energy storage system as a form of demand management for an industrial manufacturer. A thermodynamic model has been developed to evaluate the feasibility of implementing a compressed air energy storage system based on the current energy and compressed air demands of the facility. The proposed system provides some of the facilities compressed air demand, produce energy to reduce the peak demand charge incurred and produce hot water which could be utilized for a variety of industrial processes. Finally, the model is validated with data from a nearby industrial manufacturing plant and the results are analyzed and discussed.