RESUMEN
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.
RESUMEN
Environmental control system (ECS) is an assistive device to help the severely disabled persons to live their daily lives more independently. An 'ECS By Voice' suitable to a 54-year old C4 quadriplegic man was developed and installed in his own room for one week. The physical and psychologic impacts of the subject and caregiver were also evaluated using questionnaires including the Activity Pattern Indicator (API) and Beck Depression Inventory (BDI) before and after the application of the device. The results were as follows: (1) The voice recognition rate of the device was 97.5% in the laboratory and there was no difference in recognition rate according to the specific commanding words. (2) While using the device, both the dependency on the attendant care and the depression tendency of the subject were decreased. (3) While using the device, both caring time and depression tendency of the caregiver were decreased. We found the usefulness of ECS for the quadriplegics and the possibility of developing a Korean model of ECS which can be commercialized at a considerably less cost.