Numerical and Experimental ......(14)

Dozens of the papers can be found about the experimental investigations on BIPV systems,with different experimental techniques and various component focuses. Basically, they are for two main purposes. One is to report the new discoveries or present new techniques to improve the experimental measurement. As we will see the in following paragraphs, these papers (Zollner and Winter 2002; Khedari and Rungsiyopa 2004; Morgan and Harry 2002) are going to guide the following CFD models and provide with many experimental data. The other one (Moshfegh and Sandberg 1996; Park and Augenbroe 2004) is to validate the previous CFD models and compare the experimental results with the related published modeling results. 绿色建筑博客 Hh^+G9{Q]Ev

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Zollner and Winter (2002) mentioned in his paper that literature reviews showed that most of the research done in the past for electronic cooling applications has treated heat transfer by natural convection in narrow gaps. They just focused on the laminar flow situations. However, the velocity profile investigation carried out by Zollner showed that the flow was turbulent mixed flow. Due to the wind effect and turbulent variations the velocity measurement is unstable. Khedari and Rungsiyopas (2004) reported the use of a new type of vented concrete block integrating with the solar collector on the roof. They observed that the use of vented concrete block could reduce the house temperature by 2-3 ºC when the window is closed and 0.5-1 ºC when the window is open. Bazilian (2002) introduced the thermographic analysis to measurement of the BIPV system in Sydney, Australia. The BIPV interior PV array was measured up to 11 ºC hotter than the surrounding metal roofing. This showed the significance for removal of heat off the back of BIPV modules and this also provided the graphical way to view the nature of BIPV systems.

Sandberg and Moshfegh (1996) presented an experimental investigation of a laboratory mock up of a façade provided with photovoltaic elements and made data validation of his numerical model in Part I. Surface temperatures were recorded and air velocity was recorded with tracer gas technique. They found that the radiative heat transfer transfers about 40% of the heat from the heated surface to the unheated surface. At laminar flow in the channel, both surface temperature increase parallel with almost the same and constant slope, however, with transitional flow they also increase parallel but the slope varies with the distance from the bottom to top of the channel.