Design and research of liquid cooling garments in thermal environment

Liquid cooling garments (LCGs), which are considered to be a very effective way to reduce thermal erosion since the 1950s. But at present, the design and test of the liquid cooling garments system is not perfect, so it needs further research. In this study, the heat transfer model between the LCG and the environment and human body was established, and we analyzed the influence of voltage and flow rate on the cooling performance of LCG. We designed and produced a LCG prototype. Series of experiments were carried out based on the system to verify the accuracy of the heat transfer model. The experimental results show that the working voltage of the Thermo Electric Cooler (TEC) has more significant influence on the cooling effect than the flow velocity of the liquid in the pipe. Furthermore, the effective cooling power of the LCG increases first and then decreases with the increase of the working voltage, in other word, there is an optimal working voltage. In addition, the fitting relation between the working voltage and the effective cooling power is given. Besides, the experimental results also show that the cooling effect of the LCG increases with the increase of flow rate under the optimal operating voltage, and the average maximum cooling temperature difference of the cooling garment is 5.4-5.5°C when the ambient temperature is 39.2 °C. A specific cooling temperature was proposed to assess practicality and the value is 5.5 °C/kg.