The effect of leakage on pressure loss of rotary regenerative heat exchangers.

The pressure loss of the rotary exchanger is an important parameter that affects the energy consumption. Based on the literature review, the available correlations for calculating the pressure loss of rotary regenerative heat exchangers are presented in the article. The article presents extensive experimental research of rotary regenerative exchangers with different wheel geometries. A total of nine exchangers with eight different heat wheel geometries were investigated. The experiment was divided into two tasks concerning the pressure loss of the wheel channel and the total pressure loss of the built-in exchanger. The results of both approaches show differences that are caused by the leakage of rotary exchangers, which is their natural property. Based on the results
of the experiment, correlations were proposed for determining the coefficient of friction in a channel in the shape of a sinusoid and a correlation for calculating the total pressure loss of the built-in rotary exchanger. The presented correlations have been experimentally verified and can be applied with a sufficient accuracy of ±5%. The new correlations were compared with the published results. The article discusses the effect of leakage of exchangers equipped with a labyrinth seal. Based on the experimental investigation, it was found that the leakage of the examined exchangers varies in a wide range of 1 to 4% and depends on the quality of the exchanger construction.