ABSTRACT
Objective To provide a more accurate calculation method for design of condensing heat exchanger (CHX) through an in depth discussion about working conditions of the CHX commonly used in temperature and humidity control system of manned spacecraft.Methods With difference of the simplified configuration of CHX,a mathematical model was given.Specifically,the log-mean temperature difference (LMTD) method was used in dry conditions,while in wet conditions mass and energy conservation equations were used.The set of equations of the model were solved by using the shooting method provided by Matlab/Simulink program.Results The results of working conditions and the performance of heat transfer and dehumidification of CHX were determined.Analysis showed that the simulation model could evaluate performance of the CHX in different work conditions reasonably and the results were close to the physical phenomenon.Conclusion The simulation models are of significance for design and optimization of CHX both in manned spacecraft temperature and humidity control system and in aircraft environmental control system.
ABSTRACT
With the development of space exploration,high performance extravehicular activity(EVA) space suit portable life support system(PLSS) is expected.In this paper,the research progress of PLSS for EVA is introduced.The techniques of CO2 removal system and H2O removal system are key parts of PLSS.These concepts are compared and analyzed.Prospects of development of PLSS are proposed.Those mature,reliable techniques should be adopted for our country.Regenerative PLSS facilities should be investigated simultaneously.