【作者】 钟轶魁；

【导师】 陈国邦；

【作者基本信息】 浙江大学 ， 制冷与低温工程， 2003， 硕士

【摘要】 随着国际运载火箭朝着大功率和多样化的两极方向发展，大比推力的液氢液氧推进剂成为大功率运载火箭的主要推进剂。预冷技术作为低温液体火箭点火发射前不可缺少的环节之一，也代表着各个国家航天技术发展标志之一。相比传统排放式的预冷，自然循环预冷技术有着节省推进剂的预冷消耗量、简化火箭射前程序、增加预冷安全系数和实现延迟点火功能等的特点。国外在该项领域的技术已经在实际火箭发射场得以应用，相比之下，我国仍采用排放式的预冷方法。因此，需要研究低温液体火箭发动机循环预冷的方法，尽快实现赶超发达国家的目标。 本文简要回顾了运载火箭发展的历史和各个国家运载火箭研究水平。展现了循环预冷技术在各国家低温液体火箭的发展与应用，同时也介绍了预冷计算方法。随后，采用相似理论的方法将实际运载火箭方案进行微缩建模。设计出了一套详细的试验方案，据此组装了试验装置，并参照运载火箭射前程序，提供了一套详细的试验操作步骤，进行了基本型循环预冷的模拟试验。在试验基础上，对试验装置及其测量系统进行改进，完善了试验操作程序。改进后的模拟试验可以实现对实际运载火箭射前预冷的各个环节的模拟。 本文对回流管路的直径和绝热效果以及回流方法的影响进行了详细的阐述。得出了循环预冷技术在低温液体火箭发动机预冷程序中可以采用的结论。并建议采用气相回流的方法，可以实现更佳的预冷效果，其自然循环预冷可以维持更长时间，同时能更进一步简化射前程序。另外，还需要采取措施解决自然循环预冷中出现的“间歇喷泉”。最后给出了进一步开展循环预冷研究的方案建议。更多还原

【Abstract】 With the development of rocket technique and increasing requirement of large-power launch vehicle, the cryogenic propellant with higher specific impulse is applied more and more widely. Precooling technique is the key part of the prestart process of cryogenic liquid rocket. Comparing to the direct drain cool-down process used in China, the natural precooling cycle, which may save the propellant of the precooling, simplify the prestart program, delay the ignition of the rocket and be more safe in the process of precooling as well is employed in this paper.Based on the review of the historical developments of the precooling technology and the prospective applications, the present work focuses on the following sections:The simulation model, which is about a quarter of the real rocket precooling structure in volume, is created with similarity theory. The simulated experiment structure as well as measurement system and the operating procedure are introduced in this paper. Some modeling experiments have been processed, in both of the atmospheric pressure and the pressurized pressure. The conclusion can be referred to in the further experiment.The gas-phase inlet, the outlet of the reflux pipe is at above the liquid surface in the cryogenic tank, is presented. Comparing to the liquid-phase manner that the outlet of the reflux pipe is below the liquid surface in the tank, the cool-down cycle may last longer and the prestart program may be more simple in using the gas-phase inlet manner. The geysering problem which exists during the cool-down process and is harmful for the recirculation, should be solved in the application.更多还原