2016 ASHRAE Winter Conference

This paper provides an overview of recent refinements to the Radiant Time Series Method (RTSM) as part of 1616-RP. These refinements include replacing the ASHRAE three-parameter (A,B,C) clear sky model with a new globally-applicable model, introducing new design day temperature profiles, updating the weather data, and improving the treatment of interior shading in the fenestration model. In addition, the sensitivity of the calculated cooling loads to the weather-related refinements is investigated with a parametric study.

This paper extends the application of a correlation developed previously by the author for the overall heat transfer coefficients (the U-factors) of single layered fiberglass Metal Building (MB) insulation assemblies to assemblies where insulation is used in a manner designed to fill up the space (the “cavity”) between the two consecutive structural elements (purlins or girts). These assemblies may involve either single or multiple insulation layers and the cavity may be filled to various extents. The paper describes a general technical approach to calculate the thermal resistances of various regions of a MB insulation assembly, namely regions beyond, underneath, and above the structural units.

The occupancy patterns in office buildings have been becoming increasingly diverse. And, even in cases where the occupancy periods are still rigid, the time needed to bring a room from nighttime setback temperatures to the setpoint temperatures not only change in time but also vary between offices. Consequently, operators have been challenged to choose conservatively short temperature setback periods. In recognition of these challenges, a self-adaptive control algorithm that can learn the recurring occupancy patterns and the parameters of a model predicting the indoor temperature response was implemented in a southwest-facing shared office space in Ottawa, Canada.

Stationary gas turbines used in industrial applications can be run using pre-mixed air/fuel systems. Though pre-mixed air/fuel systems are widely established, research continues to further develop the efficiency of such engines. This paper uses computer numerical simulation in analyzing the effects of the pre-mixed air/fuel composition on the performance of a miniature gas turbine. The composition of the fuel-air pre-mixture was varied, results were recorded and compared. Effects on turbulence intensity in the combustion zone for various pre-mixed air/fuel compositions were monitored and compared. The analysis has shown that performance can be optimized with an optimal air/fuel pre-mixture, and that this optimal performance coincides with peak turbulence intensity at the combustion chamber downstream of the pre-mixed air/fuel injectors.