Liquid desiccant-vapor compression hybrid (LDCH) airconditioning systems are popular for reducing energy consumption. This work tests a conventional LDCH airconditioning experimental setup and establishes the corresponding mathematical model to analyze the effect of the concentrated solution branch in the solution-solution heat exchanger (SSHE) on the cooling capacity of the evaporator; the results show that the percentage of cooling capacity loss of the evaporator exceeds 10% with the small concentration difference of 1.5% in the conventional LDCH airconditioning system. Afterwards, a new LDCH airconditioning system is proposed by adopting an auxiliary regenerator to cut down the cooling capacity loss of the evaporator, and the analysis results show that there is a big temperature drop of the concentrated solution branch after being pretreated by the auxiliary regenerator; under the condition of concentration difference of 2.65%, the inlet temperature of concentrated solution branch from the regeneration side in the SSHE can decrease over 6 ℃; and the extra heat load entering the dehumidification side from the regeneration side obviously decreases. Consequently, the evaporator only needs to spend 1.5% of its cooling capacity on the compensation for the extra heat load.

Accurate predictions of the droplet transport, evolution, and deposition in human airways are critical for the quantitative analysis of the health risks due to the exposure to the airborne pollutant or virus transmission. The droplet/particle-vapor interaction, i.e., the evaporation or condensation of the multi-component droplet/particle, is one of the key mechanisms that need to be precisely modeled. Using a validated computational model, the transport, evaporation, hygroscopic growth, and deposition of multi-component droplets were simulated in a simplified airway geometry. A mucus-tissue layer is explicitly modeled in the airway geometry to describe mucus evaporation and heat transfer. Pulmonary flow and aerosol dynamics patterns associated with different inhalation flow rates are visualized and compared. Investigated variables include temperature distributions, relative humidity (RH) distributions, deposition efficiencies, droplet/particle distributions, and droplet growth ratio distributions. Numerical results indicate that the droplet/particle-vapor interaction and the heat and mass transfer of the mucus-tissue layer must be considered in the computational lung aerosol dynamics study, since they can significantly influence the precise predictions of the aerosol transport and deposition. Furthermore, the modeling framework in this study is ready to be expanded to predict transport dynamics of cough/sneeze droplets starting from their generation and transmission in the indoor environment to the deposition in the human respiratory system.

No abstract

No abstract

No abstract