Thermal Cycle and Combustion Analysis of a Solar-Assisted Micro Gas Turbine

Abstract

Abstract:The authors discuss in this paper the potential of two power plant concepts for distributed generation, based on the integration of a cogenerating micro gas turbine with a solar panel array. The first one relies on the adoption of a parabolic trough network with an intermediate thermal carrier, while the second one considers the direct heating of the working air in a solar tower system. The first solution also includes a bottoming organic Rankine cycle (ORC) plant, so that it is mainly addressed to the power output increase. The second one involves a relevant temperature increase of the air entering the combustor, so allowing a direct fuel energy saving, whose amount is strongly variable with both the solar irradiance and the eventual part-load operation. In addition, the latter solar-assisted scheme involves noticeable variations in the conditions for the combustion development. This suggested the authors to proceed with a detailed CFD analysis of the combustion, after a preliminary thermal cycle study for highlighting the main benefits from the solar integration of the power plant.

CFD Design of Hydrogenation Reactor for Transformation of Levulinic Acid to γ-Valerolactone (GVL) by using High Boiling Point Organic Fluids

“…The lower flammable limit is 0.6% (volume) at 175 • C, while the upper limit is 6.8% at 190 • C. Ignited diphenyl mixture burns slowly and is practically explosion proof as experience of operating diphenyl heating installations has proven that there is practically no fire hazard from it with proper equipment and operation. Abagnale et al [18] discussed the usage of DOWTHERM A as a working fluid in the Organic Rankine Cycle (ORC). It has been mentioned in [19] that this fluid has been successfully applied in heat pipes.…”

“…where A represents the frequency factor. It was assumed that its value was 6.2 × 10 3 (1/s); E is the activation energy with a value of 48.0 (kJ/mole) [18]; R is the gas constant (8.3143 J/(mole·K)); and T represents the temperature (K). It should be noted that this reaction is endothermic (consumes heat).…”

CFD Steady Model Applied to a Biomass Boiler Operating in Air Enrichment Conditions

“…To model this interaction, a solid enthalpy variable is created to represent the solid phase temperature in the bed region. This variable follows the steady transport Equation (1). The fluxes of the species that represent the gas phase mixture are introduced proportionally to the consumption rates of the biomass species.…”

“…The global coefficients of these reactions are shown in the Equation 7. The devolatilisation is modelled as the rate of conversion of the volatile content, and it is considered to occur at the solid phase temperature calculated following Equation (1). The char combustion is modelled as the direct char oxidation, (R.1) [30], and two gasification reactions, (R.2) and (R.3) [31], and the kinetics in these reactions (K ox g , K g,1 g and K g,2 g , respectively) are shown in Table 1.…”

“…The development of efficient combustion systems such as biomass boilers and furnaces is a key factor to establish biomass as a reliable energy source. The development of computational technology has allowed for research of the combustion phenomena through simulation models, which provide the opportunity to analyse the behaviour of combustion systems easily and reduce costs [1,2]. Modelling a biomass boiler is a complex process that requires the combination of several models and techniques, and developing a reliable and efficient simulation model is still an important challenge.…”