Sunday, December 4, 2011

Passive building with PCM and tools for analysis

Building energy consumption for it's temperature can be substantially reduced if solar energy is adequately utilized. Due to a strong need to reduce the total thermal energy requirement (both heating and cooling) in buildings, storage of thermal energy has gained prominence. The integration of phase change materials into building can provide a media to store the energy gain from solar radiation during the day and release the stored energy at night. 

Athienitis et al. (1997) performed an experimental analysis on a test-room with PCM and found that peak room temperature was reduced by 4% and reduced the heating load at night. Darkwa and O’Callaghan (2006) studied drywalls with PCM at different phase change ranges during cooling season and found that the narrow phase-change rangeof PCM was most effective to reduce room temperature by 17%.

Therefore, the implementation of PCM's can reduce the energy requirement at peak hours and, can reduce the indoor temperature fluctuations to improve the thermal comfort of occupants.
Department of Mechanical and Industrial Engineering, Ryerson University, Toronto, Canada has conducted work on comparison of corrective phase change material algorithm with ESP-R simulation. This paper summarized the results of two different methods of analysing PCM for building energy use. One method is the commonly used apparent heat capacity method and the other is the iterative corrective scheme.

When the room temperature was outside the PCM temperature range (i.e. sensible heat), both the
corrective scheme and the ESP-r model gave similar results. However, within the phase change
temperature range there were differences depending on the Fourier and Biot number. In general, the ESP-r model gave the same results as the corrective scheme when the Fourier number was reduced below unity. Work is currently being pursued to implement the enthalpy method with iterative correction into the phase change module in ESP-r and TRNSYS. Also, experiments are currently being developed to validate these models.

RGEES, LLC is manufacturer of PCM based Cold Chain Refrigerants.
More info:

No comments:

Post a Comment