Optimization of the operation mode of regenerative heat exchangers

Abstract

The paper considers the operation of regenerative heat exchangers with a fixed checkerwork. Such a checkerwork allows for high-temperature heating of gases and is made of refractory materials with a relatively high heat capacity, but low thermal conductivity. The article presents calculations of regenerative heat transfer for devices with block checkerwork. It is shown that a decrease in the equivalent diameter of the channel d e leads to an increase in the average air heating temperature over the period. An increase in the relative water section of the checkerwork f also leads to an increase in the air heating temperature, but only to a certain limit. On the one hand, with an increase in the relative water section, the specific heat exchanger surface increases. On the other hand, at a certain value f, the accumulating mass of the checkerwork significantly decreases, and as a result, the air heating temperature decreases. For the same reason, for checkerwork with a high value of the relative water section, it is necessary to reduce the duration of the heating/cooling periods of the checkerwork. The paper also examines several types of compact checkerwork, which are very promising, including in heat storage systems. It is noted that the use of such attachments in conventional regenerate heat exchangers is impossible. First, it is necessary to increase the water section of the heat exchanger and significantly reduce its height, otherwise, the pressure loss will increase sharply. Secondly, it is necessary to significantly reduce the duration of the heating/cooling periods, otherwise, due to more intense heat exchange, the air temperature at the outlet of the regenerative heat exchanger changes much more than in the block checkerwork.