Design And Development Of Water Cooling Garment Based On Human-clothing-environment Heat Transfer Model And Its Performance Evaluation

As the global warming trend intensifies,people face increased heat stress.High temperatures can cause harm to human physiology and psychology.The application of individual cooling clothing is conducive to alleviating the heat stress faced by workers in high temperature environments,improving the heat and humidity comfort of workers,and helping to cope with the increase in energy consumption and carbon emissions caused by the increasing demand for cooling due to the rise in ambient temperature..Based on the heat transfer theory,this paper establishes the human-clothing-environment heat transfer model.By using the theoretical model as the basis,the water cooling garment design is proposed and developed in kind.In addition,the performance of the water cooling garment is evaluated.First,based on the human body heat balance equation,the required heat dispating capacity under specific conditions is estimated.Then,based on the heat transfer and flow theory,the heat transfer and flow related model of the 4-pipe water-cooled garment was established,and the cold quantity was calculated by programming and simulated using the laminar model to observe the heat transfer and provide a reference for the design of the water cooling garment.Using the forming characteristics of the cross-machine fabric,a fabric structure that can be inserted into the pipeline was designed.After testing the performance of this fabric and several commonly used fabrics in terms of heat insulation,moisture permeability and air permeability,the cross-machine fabric was evaluated by fuzzy mathematical methods and found to have its advantages.Based on this,the design was carried out in terms of duct arrangement and garment structure.Next,a real-life dress experiment was adopted to recruit female subjects to evaluate the activity comfort and thermal and humid comfort of the designed water-cooled clothing.Subjects were exposed to a high temperature environment(36 ℃,50% relative humidity)simulating moderate intensity work and rest.A comparison was made between the condition without the water cooling suit(CON),wearing the design water cooling suit(E)and wearing the commercially available water cooling suit(B).Physiological indicators such as skin temperature,sweating volume and heart rate were recorded during the experiment,and a questionnaire was used to obtain subjective feelings such as thermal sensation,thermal comfort and moisture sensation during the experiment.The experimental results showed that wearing the water-cooled garment could reduce the temperature of the covered skin,increase the cool feeling,and maintain the local thermal comfort in the comfortable state,reduces whole-body thermal discomfort.The cooling effect was more obvious during the sedentary phase than during exercise.With E reduced tube length and garment weight,there was no significant difference in skin temperature,thermal sensation between B and E except for chest skin temperature.Water cooling garment reduced sweating,but reduced the evaporation rate of sweat,and had an inhibitory effect on sweat evaporation,but the inhibitory effect of E was weaker than that of B.However,as reflected by heart rate changes,a certain amount of heat storage was still generated when exercising in water-cooled clothing.In terms of activity comfort,group E achieved comfort evaluation under all movements.In particular,the comfort of movement in lateral and deep squats was significantly better than in group B.In summary,the water-cooled garment designed in this project significantly improves the thermal and wet comfort of women in high-temperature environments.This project uses the horizontal machine knitted garment as the base garment for the water cooling garment,which is conducive to individualized fit design,while reducing processing steps and saving materials.In addition,piping arrangement design and women’s garment structure design were carried out.It can provide some reference for the subsequent design and promotion of water cooling garments,helping to maintain the comfort and safety of workers.