Evaluation of performance an air conditioning systems using t-junction flash gas refrigerant
The purpose of this study was to determine the performance of air-cooled chiller system using T-junction flash gas bypass refrigerant. The experiment was conducted by installing T-junction after expansion device to separate the phase of refrigerant liquid and gas which flows to the evaporator. The working fluid is used as a cooling medium is R-290. To get performance data, measurements performed at the time of steady state when the water chilling temperature T = 15 C up to T = 10 C and flow rates kept constant at 1 GPM (6.3 x 10-5 m3/s). Finally, the use of T-junction mode in AC system generates an increase in the refrigerating effect and coefficient of performance systems (CoP) by 6% and 17.8 %, respectively. Also, it can decrease the heat of compression by 8.5%. This has implications for the lighter compressor work and saving the power consumption of the AC system.
Retrofit assessment of window air conditioner
Abstract This study investigates the feasibility of replacing R22 window air conditioners with hydrocarbon refrigerants (propane, R290) for various charged masses (25–70%), and analyzes the performance at different outside air temperatures (26, 29, 32 °C). Results indicate that the optimal charged mass for refilling a window air-conditioning unit with R290 refrigerant is approximately 50–55% of the R22 refrigerant at different outside air temperatures. In addition, a comparison of R22 and R290 refrigerants shows that the EER of the R290 refrigerant exhibits an upward trend as the outside air temperature increases, improving the EER by approximately 20% under ideal conditions. The refrigerant in most window air conditioners can be changed from R22 to R290, and the ODP and GWP of R290 are negligible comparable with those of R22 refrigerant. Replacing R22 window air conditioners with R290 can effectively enhance EER values and reduce carbon emissions.
DEM generation from new VIR sensors: IKONOS, ASTER and Landsat-7
DEM generation is a living R&D topic since new-launched satellite images can be used to generate stereoscopic images. Using a coplanarity equation model developed at CCRS and an automatic matching method developed at PCI, DEMs are generated with new VIR stereo data. Accuracy of 4.9 m with high-resolution IKONOS images, and 33 m and 101 m with medium-resolution ASTER and Landsat-7 ETM/sup +/ images respectively are obtained. The same matching accuracy of one-pixel is translated into worse results with Landsat due to a small B/H ratio of 0.15.