Experimental study of converging-diverging nozzle to generate power by Trilateral Flash Cycle (TFC)

Recovering heat from low grade heat resources for producing power is of high demand and interest. For this purpose, the an experimental study of converging-Diverging nozzle to generate power in Trilateral Flash Cycle (TFC) is investigated in this paper. In the proposed system, performance of a designed and manufactured to recover the heat and convert the heat energy to mechanical energy has been investigated. In this system, Isopentane, which is selected to be the working fluid due to its low boiling temperature, is heated by low temperature hot water and pumped through a two-phase flow nozzle, where the energy conversion takes place. In the nozzle, part of the liquid evaporates and the accelerated mixture exits the nozzle and impacts on a Pelton turbine bucket shape target. The high potential of power generation from low temperature heat resources is demonstrated through theoretical analysis. Generated force of high speed flow out of two phase nozzle has been experimentally measured in lab scale test rig and isentropic efficiency of the nozzle has been calculated based exit speed of the working fluid. Around 45% isentropic efficiency has been shown From the test results. In addition, 1.5 N4 N force increase was detected by increasing temperature of working fluid from 30 °C to 70 °C correspondingly. The results of this experiment can be applied on a power plant waste heat as a case study, where the increased energy conversion efficiency is demonstrated on the binary cycle

N95 respirator mask breathing leads to excessive carbon dioxide inhalation and reduced heat transfer in a human nasal cavity

Face masks and respirators are used to filter inhaled air, which may contain airborne droplets and high particulate matter (PM) concentrations. The respirators act as a barrier to the inhaled and exhaled air, which may change the nasal airflow characteristics and air-conditioning function of the nose. This study aims to investigate the nasal airflow dynamics during respiration with and without an N95 respirator driven by airflow through the nasal cavity to assess the effect of the respirator on breathing conditions during respiration. To achieve the objective of this study, transient computational fluid dynamics simulations have been utilized. The nasal geometry was reconstructed from high-resolution Computed Tomography scans of a healthy 25-year-old female subject. The species transport method was used to analyze the airflow, temperature, carbon dioxide (CO(2)), moisture content (H(2)O), and temperature distribution within the nasal cavity with and without an N95 respirator during eight consecutive respiration cycles with a tidal volume of 500 ml. The results demonstrated that a respirator caused excessive CO(2) inhalation by approximately [Formula: see text] greater per breath compared with normal breathing. Furthermore, heat and mass transfer in the nasal cavity was reduced, which influences the perception of nasal patency. It is suggested that wearers of high-efficiency masks that have minimal porosity and low air exchange for CO(2) regulation should consider the amount of time they wear the mask