中文摘要：

为减轻低温保护剂在添加过程中对细胞的毒性损伤，减少低温保护剂添加过程的工作量，提高操作可靠性，提出了一种以自复叠制冷系统为冷源，可对低温保护溶液进行连续降温、连续提高质量分数操作的方法，并选用二甲亚砜作低温保护剂进行了实验。通过优化制冷系统的运行，溶液的最低温度能达到约-70℃。采用可编程控制器的控制系统能实现从室温到低温的定点及连续曲线控制，并保证溶液在降温过程中其温度始终处在高于冻结点5℃以上，即不结冰的状态。研究结果表明，自复叠制冷技术在生物材料的低温保存领域具有潜在的应用前景。

英文摘要：

To alleviate the toxic damage of cryoprotective agent on cells during the adding process, reduce the labor work of the adding process and increase the operation reliability, a method of continuous cooling and continuous adding of the cryoprotective agent was suggested using an auto-cascade refrigeration system as the cooling source. Experiments were made choosing dimethylsulfoxide as the cryoprotective agent. Through the optimization of the refrigeration system, the solution temperature reached about -70℃. With the help of programmable logical controller, the solution temperature could be controlled at a fixed point or following a curve from room temperature to low temperature. With the later controlling mode, the solution temperature could be kept 5℃ higher than the freezing point, therefore the solution will not freeze. The results demonstrate that auto-cascade refrigeration technology has potential prospects in the field of biomaterial cryopreservation.