Study Of Airflow And Defroster Of Cooler In The Cooling Environment To The Very Large Telescopes With A High Dispersion Spectrograph

The spectral measurements of celestial bodies is an important means to research the state and movement of celestial objects, chemical composition and physical properties. High dispersion spectrograph is one of the important equipment of celestial spectroscopic observations. When the temperature of work environment changes, the refractive index of spectrograph prism also changes, leading to the spectrograph dispersion rate fluctuations. So ensure that the temperature when spectrograph records data is consistent with the observed temperature. The apparatus is placed in a thermostatic chamber for the accuracy of data. It is increasingly important that reasonable airflow organizational forms meet the craft air conditioning requirements.This paper is an application of Computational Fluid Dynamics in the turbulent flow of a three-dimensional air-conditioned room.Firstly, found physical model in Gambit, then partition the physical model into griddling. Choose quality conservation equation, momentum conservation equation, energy conversation equation and K-ε equation to calculate. Simulation results show the velocity and temperature field of room by an intuitive way. The results validate that the K-ε turbulence model in the numerical computation to the airflow structure of thermal non-uniform room is feasible. Compared with the experimental results, the data which measured experimentally and numerical simulation results are consistent, indicating that the simulation is reliable. The Airflow - organization indoor meet the environmental requirements of the high dispersion spectrograph, the position of the air cooler in the room is arranged reasonably. Its application is of great importance to the increase of the level of the designing project of airflow organization in the air-conditioned room, the increase of the air quality in the room, the decrease of the energy expensed in the building, the energy saving design to the heat environment of the building and the evaluation of the air quality in it.This article carried out the experiments on the natural defrosting and orderly defrosting method in the refrigeration system. Through measurement of the temperature of return air zone of the air cooler and the fins of evaporation tubes, combined with the observation, we found that when storage temperature is 5℃, stopping the compressor and opening the cooler fan, the frost which produced in the last refrigeration process can be almost removed. When the refrigeration system is working for 8 hours, the ice produced in last refrigeration process can be ridded by the method of orderly defrosting which is close the electromagnetic valve for liquid 15 minutes and ensure the storeroom temperature still dropped, the frost of evaporator surface can be almost removed.