中文摘要：

本课题设计的低温冷冻干燥机以液氮为低温冷源，通过电加热器加热液氮使之汽化，通过控制气体的压力，压出液氮。液氮被压出后流入硅油池的换热器同硅油进行充分换热。在硅油池底部布置一个电加热盘，通过调节加热量，精确控制硅油温度。特制的不锈钢搁板浸入硅油池中进行硅油浴，能够实现良好的传热。测控制系统由上位PC机与下位可编程控制器和数据采集模块共同组成，在PC机上可设置控制参数并进行监控，温度曲线可程序控制，数据采集模块能够自动采集、存储、上传各项数据，数据可以在PC机上处理。

英文摘要：

In this paper, a novel designed cryofreeze - dryer uses liquid nitrogen as its cold source, When the liquid nitrogen is heated, the internal pressure of the dewar rises, and as a result, the liquid nitrogen is compressed to flow out. Liquid nitrogen exchanges heat with silicone oil in the silicone oil pool. Under the silicone oil pool, there lays a heating disc, the temperature of the silicone oil that is controlled by the PLC. A particularly - made shelf can ensure uniform heat transfer, Supervisory measurement control systems consist of upper personal computer and lower program controller and data acquisition modules. The control values can be set on the personal computer and monitor by it. The temperature curve can be program - controlled. Data acquisition modules can automatic gather, store and upload data, The data can be processed on personal computer.