Heat and mass transfer in air-fed pressurised suits

Abstract

Air-fed pressurised suits are used to protect workers against contamination and hazardous environments. The specific application here is the necessity for regular clean-up maintenance within the torus chamber of fusion reactors. The current design of suiting has been developed empirically. It is, therefore, very desirable to formulate a thermo-fluids model, which will be able to define optimum designs and operating parameters. Two factors indicate that the modelling should be as comprehensive as possible. Firstly, the overall thermo-fluids problem is three-dimensional and includes mass as well as heat transfer. The fluid field is complex, bounded on one side by the human body and on the other by what may be distensible, porous and multi-layer clothing.In this paper, we report firstly the modelling necessary for the additional mass and heat transport processes. This involves the use of Fick's and Fourier's laws and conjugate heat transfer. The results of an initial validation study are presented. Temperatures at the outlet of the suits were obtained experimentally and compared with those predicted by the overall CFD model. Realistic three-dimensional geometries were used for the suit and human body. Calculations were for turbulent flow with single-and twocomponent (species) models.

Experimental investigation of the effects of personal protective equipment on thermal comfort in hot environments

“…On the one hand, special PPE with ventilation and cooling can be customized for healthcare workers. Some studies [ 28 , [51] , [52] , [53] , [54] ] have tried to install fans on the PPE for cooling and ventilation to alleviate thermal discomfort. On the other hand, cooling vest with phase change materials (PCMs) or ice can be included underneath the PPE.…”

Field investigation of the heat stress in outdoor of healthcare workers wearing personal protective equipment in South China

“…Previous studies have improved the waterproofing and moisture permeability of protective clothing by improving the PPE materials [(36); Pan et al, 2019 (37); (38,39), Yang, 2019 (40); (41)]. Some studies report installing fans on PPE for cooling and ventilation (11,26,(42)(43)(44)(45). However, those methods may increase the risk of infection.…”

Design optimisation of air-fed full pressurised suits

“…The unknowns of the model are the three velocity vectors U, V, W, pressure p, temperature T and the effective viscosity μ e . These are solved using ANSYS-CFX a commercial CFD package (in excess of 270,000 nodes) ( Figure 3) by defining a set of boundary conditions and coefficients that are applied to the conservation of mass, momentum, energy and turbulence models in the form of the non-linear partial differential equations detailed below [4], [5] and [6] (1)…”