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PSE: a Fortran program for modeling well-stirred reactors
Abstract
In this report the set of algebraic equations describing the perfectly stirred reactor is described first. Then the time-dependent equations are presented; unlike the algebraic equations the transient equations can be solved without such a good initial estimate. A method to calculate the first-order sensitivity coefficients of the mass fractions and temperature with respect to the rate constants is also given. The PSR code is not a stand-alone program; it is designed to be run in conjunction with the CHEMKIN program, which handles the chemical reaction mechanism and the thermodynamic properties. In addition, it uses a modified version of the STANJAN program to provide the possibility of using equilibrium compositions as initial solution estimates. The structure of the code is described in this report, and instructions for setting up and using the code are given. Finally, an example problem is presented. 18 refs., 2 figs.
... Although the PSR model is also an idealized homogeneous model describing a type of reactor where the contents are perfectly mixed, it includes an important parameter, namely the residence time, which affects the extent of reaction and product yield. 42 The PSR is also an important model for estimating flame extinction. 43 Thus, the inhibitory effect of ammonia in hydrogen/air flames can be investigated within the framework of the PSR model as well. ...
This study numerically investigates the potential use of ammonia as a chemical inhibitor in hydrogen/air premixed combustion systems, aiming to reduce the risks associated with hydrogen use. Various flame configurations are explored using zero-dimensional and one-dimensional reacting models, including the homogeneous reactor, perfectly stirred reactor, unstrained premixed flame (freely propagating and quenching), and strained premixed flame in counterflow. The impact of ammonia addition on key flame behaviors, such as the ignition delay time, laminar burning velocity, flame thickness, and extinction strain rate, is evaluated. Results show that adding 20% ammonia achieves up to 50% inhibition efficiency across these metrics. Furthermore, heat release rate analysis is conducted for unstrained premixed flames during both free propagation and head-on quenching. It is found that the controlling elementary reactions contributing to the heat release rate differ significantly between these two phases. The study also examines the environmental implications of ammonia addition, particularly regarding NOx and N2O emissions. While pure stoichiometric hydrogen/air combustion produces minimal NOx and N2O, the addition of ammonia results in emissions on the order of (10)3 ppm or higher, indicating significant environmental challenges. This dual focus on inhibition and emission informs future strategies to balance the efficiency and environmental impact of hydrogen combustion systems. This study emphasizes the importance of experimental validation and encourages future experiments to collect data for further research.
... Both skeletal mechanisms were also validated independently using PSR [63] and laminar flame speed simulations through PREMIX [64], phenomena not employed to generate kinetics data in the reduction procedure. Figure 11 shows the validation of the comprehensive and high-temperature mechanisms in PSR with an inlet temperature of 300 K over pressures of 1, 5, and 40 atm, equivalence ratios of 0.5-1.5, and a range of residence times. ...
A novel implementation for the skeletal reduction of large detailed reaction mechanisms using the directed relation graph with error propagation and sensitivity analysis (DRGEPSA) is developed and presented with examples for three hydrocarbon components, n-heptane, iso-octane, and n-decane, relevant to surrogate fuel development. DRGEPSA integrates two previously developed methods, directed relation graph-aided sensitivity analysis (DRGASA) and directed relation graph with error propagation (DRGEP), by first applying DRGEP to efficiently remove many unimportant species prior to sensitivity analysis to further remove unimportant species, producing an optimally small skeletal mechanism for a given error limit. It is illustrated that the combination of the DRGEP and DRGASA methods allows the DRGEPSA approach to overcome the weaknesses of each, specifically that DRGEP cannot identify all unimportant species and that DRGASA shields unimportant species from removal. Skeletal mechanisms for n-heptane and iso-octane generated using the DRGEP, DRGASA, and DRGEPSA methods are presented and compared to illustrate the improvement of DRGEPSA. From a detailed reaction mechanism for n-alkanes covering n-octane to n-hexadecane with 2115 species and 8157 reactions, two skeletal mechanisms for n-decane generated using DRGEPSA, one covering a comprehensive range of temperature, pressure, and equivalence ratio conditions for autoignition and the other limited to high temperatures, are presented and validated. The comprehensive skeletal mechanism consists of 202 species and 846 reactions and the high-temperature skeletal mechanism consists of 51 species and 256 reactions. Both mechanisms are further demonstrated to well reproduce the results of the detailed mechanism in perfectly-stirred reactor and laminar flame simulations over a wide range of conditions.
... The primary target of the model development was to be able to make predictions about the effectiveness of primary NOx-reducing measures depending on the respective burner design with the help of a coupled chemical reactor network consisting of several PSR's (Perfectly Stirred Reactor) (Glaborg et al., 1986). Within a Python-based program, the chemical kinetics were solved using the open-source library Cantera (Goodwin et al., 2022). ...
... The primary target of the model development was to be able to make predictions about the effectiveness of primary NOx-reducing measures depending on the respective burner design with the help of a coupled chemical reactor network consisting of several PSR's (Perfectly Stirred Reactor) (Glaborg et al., 1986). Within a Python-based program, the chemical kinetics were solved using the open-source library Cantera (Goodwin et al., 2022). ...
... Flow reactor experiments were modeled as isobaric batch reactors, offering options for isothermal conditions or incorporating imposed temperature profiles observed in literature experiments when available [14,16,58]. Simulations of jet-stirred reactor experiments were implemented as open, isobaric, and isothermal perfectly stirred reactor systems [80], maintaining experimental steadystate temperatures. Shock tube experiments were simulated using an isochoric homogeneous reactor model, with prescribed non-reactive pressure histories obtained from literature experiments [45,[50][51][52]. ...
... It is assumed for the PSR model that the inlet gas mixture mixes infinitely fast with the gas mixture inside the reactor. The mathematical formulation follows the one from Ref. [40]: ...
In this study, we conduct a thorough evaluation of the STGSA-generated skeletal mechanism for C2H4 /air. Two STGSA-reduced mechanisms are taken into account, incorporating basic combustion models such as the homogeneous reactor model, one-dimensional flat premixed flame, and non-premixed counterflow flame. Subsequently, these models are applied to more complex combustion systems, considering factors like flame-flow interaction and flame-wall interaction. These considerations take into account additional physical parameters and processes such as mixing frequency and quenching. The results indicate that the skeletal mechanism adeptly captures the behavior of these complex combustion systems. However, it is suggested to incorporate strain rate considerations in generating the skeletal mechanism, especially when the combustion system operates under high turbulent intensity.
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