Simulation of an integrated hydrogen fuel cell with LIBR-water absorption system for combined production of electricity, cooling and hot water

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.In this paper, a computer simulation was performed to analyze the integration of a hydrogen solid oxide fuel cell (SOFC) with a LiBr-water absorption system, for the simultaneous production of electricity, cooling and hot water. The exhaust gases from the SOFC are used to power the generator of the absorption system, where cooling is obtained, and also to produce hot water in a heat exchanger. For the purpose of enhancing the energy utilization efficiency of the system, heat exchangers are also used to preheat the reactant streams of the SOFC with the exhaust gases. A steady state mathematical model was developed to simulate the performance of the whole system under different operating conditions. The performances of the integrated energy system and of the different subsystems are evaluated under different operating conditions. Especially, the effect of the absorption system generation temperature was scrutinized in order to determine optimum operating conditions.dc201

Natural convection analysis in vertical upright-angled triangular cavities with uniformly heated vertical wall and isothermally cooled hypotenuse

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.Steady-state laminar natural convection in triangular enclosures is of interest in many engineering applications such as buildings and electronic equipment. This paper presents an analytical and numerical computation of laminar natural convection in vertical uprightangled triangular cavities filled with air. The vertical wall is uniformly heated; a prescribed cold temperature is assigned at the inclined wall; while the upper horizontal wall is assumed thermally insulated. The defining aperture angle φ is located at the lower vertex between the vertical and inclined walls. The finite element method is implemented to perform the computational analysis for three aperture angles φ (= 15º, 30º and 45º) and height-based Rayleigh numbers ranging from a low Ra = 0 (pure conduction) to a high 109. Numerical results are reported for the buoyant velocity and temperature fields as well as the mean convective coefficient at the heated vertical wall. The numerical computations are also focused on the determination of the value of the maximum or critical temperature along the hot vertical wall.dc201

Propagation of uncertainty in a rotating pipe mechanism to generate an impinging swirling jet flow for heat transfer from a flat plate

In Computational Fluid Dynamics (CFD) studies composed of the coupling of different simulations, the uncertainty in one stage may be propagated to the following stage and affect the accuracy of the prediction. In this paper, a framework for uncertainty quantification in the computational heat transfer by forced convection is applied to the two-step simulation of the mechanical design of a swirling jet flow generated by a rotating pipe (Simulation 1) impinging on a flat plate (Simulation 2). This is the first probabilistic uncertainty analysis on computational heat transfer by impinging jets in the literature. The conclusion drawn from the analysis of this frequent engineering application is that the simulated system does not exhibit a significant sensitivity to stochastic variations of model input parameters, over the tested uncertainty ranges. Additionally, a set of non-linear regression models for the stochastic velocity and turbulent profiles for the pipe nozzle are created and tested, since impinging jets for heat transfer at Reynolds number of Re = 23000 are very frequent in the literature, but stochastic inlet conditions have never been provided. Numerical results demonstrate a negligible difference in the predicted convective heat transfer with respect to the use of the profiles simulated via CFD. These suggested surrogate models can be directly embedded onto other engineering applications (e.g. arrays of jets, jet flows impinging on plates with different shapes, inlet piping in combustion, chemical mixing, etc.) in which a realistic swirling flow under uncertainty can be of interest

Data for: Influence of the refrigerant charge in an R407C liquid-to-water heat pump for space heating and domestic hot water production

The Excel file contains raw experimental data of 75 experiments.Measured parameters include: temperatures (T), gauge pressures (P), volumetric flow rates (V), compressor electric power (Welec) and atmopheric pressure.See Figure 1 of the paper for the numbering and position of the different sensors.See Table 1 of the paper for the types of sensors used and their accuracies

Data for: Performance analysis of a R407C liquid-to-water heat pump: effect of a liquid-vapor heat exchanger and domestic hot water production

The Excel file contains raw experimental data of 64 experiments.Measure parameters include: temperatures (T), gauge pressures (P), volumetric flow rates (V), compressor electric power (Welec) and atmopheric pressure.See Figure 1 of the paper for the numbering and position of the different sensors.See Table 1 of the paper for the types of sensors used and their accuracies

Data for: Performance analysis of a R407C liquid-to-water heat pump: effect of a liquid-vapor heat exchanger and domestic hot water production

The Excel file contains raw experimental data of 64 experiments.Measure parameters include: temperatures (T), gauge pressures (P), volumetric flow rates (V), compressor electric power (Welec) and atmopheric pressure.See Figure 1 of the paper for the numbering and position of the different sensors.See Table 1 of the paper for the types of sensors used and their accuracies.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV