1 / 6

Transient conservation of mass and conservation of energy

ME 525: Combustion Lecture 7: Coupling of Chemical and Thermal Analyses, Constant Volume, Constant Pressure Reactors. Transient conservation of mass and conservation of energy principles coupled with concepts associated with chemical reactions

una
Download Presentation

Transient conservation of mass and conservation of energy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ME 525: CombustionLecture 7: Coupling of Chemical and Thermal Analyses, Constant Volume, Constant Pressure Reactors • Transient conservation of mass and conservation of energy • principles coupled with concepts associated with chemical reactions • including equilibrium and finite rate reactions. • Constant Pressure Reactors • Constant Volume Reactors • Applications of Reactor Models

  2. Transient Conservation of Mass Equations • For a control mass • For Ideal Gas in a control mass • For P-dv work mode in the control mass

  3. Transient Conservation of Species Equations • For a control mass • Summing over all species must retrieve • conservation of mass

  4. Transient Conservation of Energy Equation • For a control mass • Defining heating value and average specific heat of the • mixture

  5. Control Mass Reactor Model Summary • Energy (1), Species (N), Mass Conservation (1) and Constitutive (eg. P-v-T relationship) Energy Species Mass Text Book derives the reactor equations on a molar basis for constant volume and constant pressure and on a mass basis for the well stirred and plug flow reactors.

  6. Applications of Reactor Models • Combustion in Otto and Diesel Cycle Engines using constant volume • and constant pressure reactor theory for cycle analyses including • challenges such as engine knocks, fuel blending, fuel flexibility, and • engine control algorithms (See example 6.1). • Combustion in Gas turbine engines and rocket engines using well stirred • (See Example 6.2, 6.4), plug flow and network (see Fig. 6.12) reactors. • Reactor networks allow consideration of global as well as detailed • chemistry and a combination of the two. Additional approximations • such as full or partial equilibrium of some species and ultra-slow, fast, • and ultra-fast reactions of other species. • Reactor networks also allow consideration of additional heat transfer • and work modes such as radiation heat transfer and electrochemical • work for applications including those involving batteries. • Some models of turbulent combustion rely on reactor networks of various • sizes and time scales.

More Related