Earticle

Heat exchangers are the most effective devices for transferring heat energy in cryogenic fluid equipment. In a cryogenic thermodynamic venting system, the heat exchanger is immersed in a cryogenic liquid and operated to facilitate the heat exchange between the fluids within the heat exchanger. In this unique environment, heat is continuously introduced into the heat exchanger from the external surroundings. This study aimed to numerically investigate the impact of an external heat load on the performance of a heat exchanger. This study assessed the changes in the effectiveness of the heat exchanger when exposed to an external heat load. Specifically, the influence of a linear and constant external heat load along the length of the heat exchanger on its efficiency was analyzed. In addition, this study examined the effect of the external heat load on the effectiveness of a plate-type counterflow heat exchanger. The research findings indicated that the external heat load had a lesser impact on effectiveness reduction when it entered the heat exchanger as a cold fluid rather than a hot fluid. In addition, the decrease in effectiveness was less pronounced when the external heat load was concentrated in the high-temperature region as opposed to a uniform amount of external heat load entering the heat exchanger along its length. The effect of the external heat load based on the number of plates in a plate heat exchanger showed no correlation.

Recent commercial buildings are suffer from thermal performance degradation and increased cooling load through windows expecially in the heat wave. One of the advanced approaches is to install an exterior shading system to block incoming solar radiation to the building. This study try to evaluate the thermal performance and the cooling load reduction effect when a EVB(External Venetian Blind) system is installed in a building in the heat wave. The evaluation was conducted in a real building for 4 weeks in the heat wave. Simulation was also conducted to see the performance in other conditions. As a result, PMV was improved by 0.51~0.62 from the experiment and cooling load reduction rate was evaluated about 11%~39% from the simulation study.