This article presents an experimental analysis of cooling buildings using night-time cold accumulation in a phase change material (PCM). The free-cooling principle is explained and some of the types of PCMs suitable for summer cooling are listed. An experiment was conducted using paraffin with a melting point of 22?C as the PCM to store cold during the night-time and to cool hot air during the daytime in summer. Air temperatures, heat fluxes and heat as a function of time are presented for different air velocities and inlet temperatures.
COBISS.SI-ID: 11484187
This article presents a novel monitoring method of abrasive water jet (AWJ) cutting process using the infrared thermography. Using this monitoring method it is possible to observe the cutting front in the workpiece and thus to determine the working efficiency of the material removal process. Experimental results showed that it is possible to obtain time versus temperature images which by further computer analysis give better insight in the process. Complex cybernetic structure was defined in order to achieve adaptive control of AWJ cutting.
COBISS.SI-ID: 11478555
This paper deals with the dynamic effects related to the operation of a high-speed, clearance-sealed realization of the piston prover concept. Its dynamic characteristics are analysed by means of pressure-response measurements and mathematical modelling. The experimental results show that the pressure oscillations could be related to the resonance effects of the piston oscillator, which is excited by the flow instabilities of the gas flowing. A new, modified flow equation of the piston prover, which considers the polytropic index as an input variable, is proposed.
COBISS.SI-ID: 11756315
The influence of climate changes on buildings energy demand was analyzed. These predicted temperature rise (+1 °C and +3 °C) and solar radiation increase (+3% and +6%). With the selection of these scenarios, we covered the spectra of possible predicted climate changes in Slovenia. The results show that heating demand would decrease from 16% to 25% in sub alpine region, while in Mediterranean region the rate of change would not be significant. Summer time requires up to six times more energy for cooling in sub alpine region and approximately two times more in Mediterranean region.
COBISS.SI-ID: 6269049
This paper describes the application of exergy analysis on human heat and mass exchange with environment. Basic heat and mass transfer is calculated with standard two-node human physiological model. The results provide insight into the complex interaction between human body and environment characterized with the exergy destruction. Furthermore the analysis indicates that at given physiological parameters only a certain combination of environmental conditions ensures minimal exergy destruction what coincides with expected level of thermal comfort.
COBISS.SI-ID: 11577115