Study On Thermo-hydro Transfer Performances Of Splashed Hot Water Impact In Fabric

In the field of thermal protection, researches are mainly focused on the protective performance of fabrics and clothing in strong heat or low heat radiation conditions. However, practitioners in fire, emergency rescue, natural gas and other industry, are likely to get heat damage from high-temperature steam and hot liquid splashes, etc. Study on thermo-hydro transfer, which caused by splashed hot water, could have significant impacts on fabric’s thermal protective performance researches. Currently, studies on fabric’s thermo-hydro transfer performance are concentrated on the evaluation and improvement of fabric’s thermo-hydro comfortability, while circumstances involved external water flow would be different from the experimental condition. In the study of high temperature thermal protection against splashed hot stream, those large amounts of moisture transfer could bring complex influence on thermo-hydro transfer status. Water temperature, velocity and angle of incidence could also affect the thermo-hydro transfer process. This paper conducts further research on the characteristics showed by splash hot stream when it has thermo-hydro transfer in fabrics, takes fully exploration on impacts of the thermo-hydro interactions on fabric’s thermal protective performance, and provides more adequate basis for researches and evaluations of hot stream protective performance.This paper assesses moisture transfer performance, heat transfer performance, and thermal protective performance when splashed hot stream impacts different fabrics. Also, it uses Matlab to do the image processing and skin burns simulation test, and in the end improves the whole evaluation system of thermo-hydro transfer process and thermal fabric protective performance.Through orthogonal experiment, it discovers influence factors of thermo-hydro transfer performance not only from fabrics’ physical properties aspect but also from water impact circumstance aspect.When conducting moisture transfer performance experiment, diffusion area, penetration amount and water content are selected as evaluation indicators, fabric surface water flow profile and flow characteristics were analyzed. Analysis showed that splashed hot water flows’ profiles are related to the characteristics of fabrics’ surfaces, also, flow diffusion area is significantly positive correlated with water storage capacity and penetration. Furthermore, changes of water impact circumstances have different degrees of impact on different moister transfer performance indicators.In heat transfer performance and hot water protective performance experiment, sensors’ temperatures corresponding to their position of the inner and outer fabric surface are selected as a heat transfer performance evaluation indicator, also, the second-degree burn time is picked as the thermal protective fabric evaluation indicator. Analysis showed that the outer surface of the fabric temperature field distribution is closely related to the flow and diffusion condition. In the heat transfer process of the inner and outer fabrics’ surfaces, the fabric itself has a relatively low heat conduction effect, while the penetration of moisture convective heat is the main source of heat release. Since there are differences for thermal protective performance in different parts of fabrics, water impact circumstances could lead to different skin burns distributions. The increase of liquid water content storage in cooling phase and penetration in water impact stage would aggravate skin burns.This paper provides an evaluation method for fabrics’ thermo-hydro transfer performances under splashed hot stream impact conditions,verifies the feasibility of image processing technology in fabrics’ thermo-hydro transfer performances experiments, explores new research directions on fabrics’ thermo-hydro transfer performance testing, and also offers theoretical and technical support in the field of fabrics’ thermo-hydro transfer. Further exploration of the thermo-hydro transfer and fabrics’ thermal protective performances provides a reference test method for the study of fabric thermal protective performance, and also provides data and theoretical support for the research of fire-proof suit and other special industry work suits.