Теоретичне та експериментальне дослідження теплообміну в каналі з гранульованою насадкою.

The efficiency of air heat accumulation by a granular nozzle of a soil regenerative heat exchanger and the possibility of modeling the processes of thermal front propagation along the nozzle length over time are investigated. One of the options for the use of a regenerative apparatus with a dense layer, for which the heat source is solar radiation, and the regenerator itself is designed to maintain the required temperature climate in greenhouses. The results of the pilot installation test in field conditions are given. The temperature distribution curves along the length of the heat exchange channel for different moments of heating time of the granular nozzle are obtained. A study of the process of heat transfer between air flow and the share of gravel in the channel. It is established that the differences in wall and particle temperatures are insignificant, as a result of which the error of temperature measurements on radiation can be neglected. It was found that the heat accumulated by the particle was transferred to the environment for a long time, which indicates the rationality of the use of gravel as a granular nozzle for regenerative heat exchangers. The analysis of the course of curves on the surface of the particle and in the middle is carried out. It is determined that the law of temperature change is the same for all points of the particle. Computer simulation of the process of heating a dense layer of particles in the heat exchange channel has been performed. The analysis of temperature distribution along the length of the heat exchange channel for different heating periods is carried out. Computer simulations have been shown to be able to predict the rate of thermal front propagation for arbitrary output data and to determine, depending on the conditions of use, the geometric characteristics of the duct and operating parameters such as temperature and air flow, duration of heating and cooling periods. [ABSTRACT FROM AUTHOR]