A full approach to Earth-Air Heat Exchanger employing computational modeling, performance analysis and geometric evaluation

Computational Modeling of an Earth-Air Heat Exchanger Integrated with Phase Change Materials: A Case Study Performed for the Viamão City, Rio Grande do Sul State, Brazil

“…Transfer Phenomena in Fluid and Heat Flows XIV The experimental study of [13,22] carried out in the Viamão city, Rio Grande do Sul State, Brazil, in 2007 (geographical coordinates: 30°04' 51" S, 51°01' 24" W and altitude of 111 m), were used for validation. In addition, a verification was also carried out, comparing the results obtained in the current research with numerical values of the Simplified Model proposed by [24] and the model developed by [14], in relation to the same location. For these comparisons, Pearson's correlation coefficient (r), mean absolute error (MAE) and mean absolute percentage error (MAPE) were adopted.…”

“…The thickness of the duct wall was not considered in the computational approach. This simplification has usually been done in the literature [7,8,5,11,13,14]. The EAHE computational model employed here was proposed in Brum et al [24], and since then it has been used in several works [6,7,8,15].…”

“…To obtain the temperature field in the soil for both computational models, the energy conservation equation of soil was used [15,16]; the transient air flow inside the duct was considered incompressible and in the turbulent regime, applying the mass, momentum and energy conservation equations [15,16,17,18]; and to address turbulence, the standard kmodel was applied [17,19]. More information about the EAHE computational model can be found in [14].…”

“…The convergence criterion for energy was 10 −6 , while for the others, i.e., mass, momentum, turbulence kinetic energy and its dissipation rate, it was 10 −3 [8,5,14,23]. The simulations carried out for this work represent a time interval of 2 years.…”

“…The simulations carried out for this work represent a time interval of 2 years. Thus, a time step of 3600 s was adopted with a total of 17520 steps, and a maximum of 200 interactions per time step, according to [14]. However, only the second year was considered in the evaluation of the results, the first year being used for soil temperature stabilization.…”