Development And Comfort Evaluation Of Electrically Heated Suit For Medical Rescue

In order to alleviate the cold damage of the cold environment to the medical rescue workers and improve comfort of rescue suit,this article developed an electrically heated suit for medical rescue with the application of individual cold protection system,evaluated its performance through human wearing trails,and explored the influence of intermittent heating protocol on human thermal comfort.Firstly,this article developed an electrically heated suit for medical rescue,selecting and designing heating materials,heating areas,fabric,accessories and structure.The final application of heating materials was graphene electric heating pad with better electric heating performance.According to the local heat demand and heat transfer characteristics of human body,the graphene electric heating pads were selected to be placed on the chest,back and thigh.In terms of fabric and accessories,this article chose nylon Oxford fabric with better comfort and durability as the fabric of electrically heated suit for medical rescue,chose quilted cotton as the insulation layer,and pure cotton as the inner fabric.The structure and storage design of the electrically heated suit for medical rescue were determined from the aspects of functional reauirements and the characteristics of the electric heating system.Secondly,the positive and negative effects of the electrically heated suit for medical rescue under the continuous heating protocol(heating power 7.5 W)on human thermal comfort were evaluated through human wearing trails.In an artificial climate warehouse with air temperature of-5 ± 0.5 ?,relative humidity of 50 ± 5% and wind speed of less than 0.1 m/s,the thermal insulation effect of the electrically heated suit for medical rescue under continuous heating protocol and no heating protocol was compared.The experimental results showed that the average skin temperature of the medical rescue suit in the continuous heating protocol is up to1.7 ? higher than that in the non-heating protocol.However,the local skin temperature of the chest,shoulder and thigh reached over 34 ? for a time,and the highest temperature of the chest reached over 36 ?.The high local temperature reduced the overall thermal comfort.Finally,the degree of thermal comfort of human body and the power consumption of clothing under the three intermittent heating modes were compared to select the heating protocol that can save energy and improve the thermal comfort.Three intermittent heating protocols are chosen for this work,i.e.,an incremental decrease(every 2 min)of electric power from 10 to 0 W followed by an increase of electric power from 0 to 10 W(denoted as IP-1),intermittent heating of electric power at 5/10 W every 2 min(denoted as IP-2),and intermittent heating of electric power at 10 W in 2 min ON/OFF(denoted as IP-3).The grey clustering method was used to comprehensively evaluate the medical rescue suit with different heating protocols.It was found that the electrically heated suit for medical rescue under IP-1 and IP-2had the best comprehensive performance,and IP-1 saved the most energy(the power consumption of IP-1 was only 54% of CP,and only 56% times of IP-2).In addition,this study also evaluated the influence of electric heating elements on the activity comfort,simulated the medical rescue action at the disaster site,and compared the activity comfort between wearing electric heating medical rescue suit and wearing ordinary medical rescue suit through human wearing trail.The results confirmed that the electric heating element in the medical rescue suit did not produce a strong sense of restraint and discomfort to human activities.In summary,the electrically heated suit for medical rescue developed in this project has good warmth preservation and high comfort.The intermittent heating scheme proposed by the project has effectively improved the problem of excessive local temperature.Among them,the electrically heated suit for medical rescue under IP-1 intermittent heating protocol has the best comprehensive performance,and saves nearly 50% energy consumption compared with continuous heating.The achievement of this study could provide some reference for the optimization design of protective clothing,which has theoretical and practical application value.