Tuesday, January 26, 2016: 8:00 AM-9:30 AM
Systems and Equipment
Chair:
Reinhard Radermacher, Ph.D., University of Maryland
Sponsor: Publishing and Education Council
This session offers presentations based on a select group of recently published papers from the ASHRAE journal, "Science and Technology in the Built Environment," regarding new research in refrigerants with low global warming potential, response strategies for variable air volume (VAV) HVAC systems and fast fluid dynamics.
1 Dynamic Simulation and Analysis of Ancillary Service Demand Response Strategies for VAV HVAC Systems
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David H. Blum, Massachusetts Institute of Technology |
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Leslie Norford, Ph.D., Massachusetts Institute of Technology |
Output variability and low generating inertia associated with solar and wind electric power generation increase the requirement of grid-scale flexibility services, called ancillary services. Commercial buildings consume a significant portion of electricity in the United States and can help provide demand-side ancillary services through use of their HVAC systems. In order to investigate the performance of a common commercial HVAC system while providing ancillary services, a dynamic model of a representative variable air volume system was developed. The model has been used to simulate and evaluate the provision of spinning reserve and regulation ancillary services using common demand response strategies.
2 Accelerating Fast Fluid Dynamics with a Coarse-Grid Projection Scheme
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Mingang Jin, Ph.D., Purdue University |
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Qingyan Chen, Ph.D., Purdue University |
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Wei Liu, Purdue University |
Fast fluid dynamics (FFD) is an intermediate model that can provide fast and informative building airflow simulations. To further increase the computing speed of FFD, this study proposed applying the coarse-grid projection (CGP) scheme in FFD, which solves the momentum equation on the fine grid level and the pressure equation on the coarse grid level. Through validating the CGP scheme with building airflows of varying complexities, this study found that it could significantly accelerate simulation speed of FFD while not causing negative impact on the simulation accuracy.
3 Performance Ranking of Refrigerants with Low Global Warming Potential
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Mark Kedzierski, Ph.D., National Institute of Standards and Technology |
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J. Steven Brown, Ph.D., P.E., The Catholic University of America |
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Junemo Koo, Ph.D., Kyung Hee University |
This presentation describes an evaluation of the cycle performance of thirty-nine refrigerants identified in the AHRI low global warming potential (GWP) Alternative Refrigerants Evaluation Program (Low-GWP AREP) in a typical air-conditioner. A methodology was developed using weighting factors to rank the alternative refrigerants either emphasizing the importance of large COP or the importance of reduced system size. The two ranking methodologies produced different rankings of the alternative refrigerants; however, the top three ranked refrigerants had at least two refrigerants in common with each other.