Numerical modeling transient response of tubular cross flow heat exchanger

Abstract

Purpose The paper aims to present the mathematical modeling of plate fin and tube heat exchanger at small Reynolds numbers on the water side. The Reynolds number of the water flowing inside the tubes was varied in the range from 4,000 to 12,000. Design/methodology/approach A detailed analysis of transient response was modeled for the following changes in the operating parameters of the heat exchanger: a reduction in the water volume flow, an increase in the water volume flow and an increase in the water volume flow with a simultaneous reduction in the air flow velocity. Findings The results of the numerical simulation of a heat exchanger by using experimentally determined water-side heat transfer correlation and theoretical correlation derived for the transition tube flow agree very well. The relationship to calculate the air-side Nusselt number was determined experimentally. The correlation for the air-side Nusselt number was the same for the theoretical and experimental water side correlation. Research limitations/implications The correlation for the air-side Nusselt number as a function of the Reynolds and Prandtl numbers is based on the experimental data and was determined using the least squares method. Originality/value The form of the relationship that was used to approximate experimentally determined water-side Nusselt numbers is identical to the theoretically derived formula for the transition range. The experiments show that the relationship for the water-side Nusselt number in transition and turbulent flow regime that was obtained using theoretical analysis gives quite satisfactory results.

Numerical modeling of heat transfer in the fixed-matrix regenerator working in the Electric Thermal Storage heating system

“…The test facility is equipped with the plate fin-and-tube heat exchanger, as shown in Fig. 1, being investigated and tested in a broad range of previous papers [11][12][13][14][15][16][17][18]. Subsequently, during the discharge period, when electricity price is high (daytime, and on-peak periods), the stored heat is gradually released and used for space heating.…”

Determination of heat transfer coefficient in a T-shaped cavity by means of solving the inverse heat conduction problem

“…Based on the classification of inverse problems presented in Dulikravich et al (1999), the problem considered here is a problem of boundary conditions identification. Inverse problems related to the heat transfer coefficient determination are discussed in some papers (Maciejewska and Piasecka, 2017; Maciejewska, 2017; Maciejewska et al , 2016; Maciejewska et al , 2018; Maciag and Jehad Al‐Khatib, 2000; Taler and Korzen, 2018; Kalidasan et al , 2018; Grysa et al , 2018; Hào et al , 2013; Beck and Osman, 1989; Piasecka and Maciejewska, 2012; Zmywaczyk et al , 2014; Taler, 2007; Taler et al , 2014; Chen et al , 2007; Grysa et al , 2012; Ocłoń et al , 2018), among others.…”