View Factor Orientation (or View factor or shape factor) plays an important role in radiation heat transfer. View factor is defined as, "fraction of radiation leaving surface 'i' and strike 'j' ". Summation Rule (View Factor) If there is are similar surfaces 'i' and 'j' , then: Blackbody Radiation Exchange Radiation Exchange between Opaque, Diffuse, Gray surfaces in an Enclosure 1. Opaque 2. Surfaces 3. Two surface enclosure Radiation Shield It is used to protect surfaces from radiation act like a reflective surface. References: Material from Class Lectures + Book named Fundamentals of Heat and Mass Transfer by Theodore L. Bergman + My knowledge. Photoshoped pics are developed. Some pics and GIF from Google. Videos from YouTube ( Engineering Sights ).
Get link
Facebook
X
Pinterest
Email
Other Apps
Cogeneration
Get link
Facebook
X
Pinterest
Email
Other Apps
-
Cogeneration
It is defined as, "Sequential generation of two different forms of energy from a single source (generally mechanical and thermal energy, Combined Heat & Power Generation)".
For E.g.: Warm pool water with Lower Costs and Lower Emissions of Conventional powerplant.
Technical Options for Cogeneration
Cogeneration is not used by large industries.
For constant temperature heating or drying, steam is very good (since isothermal conditions can be maintained allowing saturated steam to condensed (at that temp) utilizing latent heat.
Reduction of Carbon Emissions
1. Reciprocating Engine Cogeneration Systems
It is defined as, "Utilizing one source (diesel/gas engine) to produce electricity energy converted into heat water (process heat)".
Steps:
Burning of Fuel in engine ↦ Produce heat ↦ Produce electricity ↦ engine is cooled by coolants ↦ which transfer heat contents into circulating water ↦ which is further heated in boiler.
2. Gas Turbine Cogeneration Systems
Steps:
Fuel + air ↦ Compressed + Burn in compressor ↦ hit to turbine blades (expands) ↦ which make shaft to rotate, which produce electricity ↦ remaining heat is used to heat water.
3. Steam Turbine Cogeneration Systems
It is similar to Rankine Cycle but Condenser is replaced by Process Heater (which gives process heat as per our requirement).
Additional Components ↦ process heater + pump.
Continuously bled steam in process heater.
Steps:
Fuel burn in boiler ↦ Steam produced ↦ hit turbine blades ↦ Electricity generated ↦ Steam enter process heater ↦ Exchange heat with cold chemicals.
There are two types of Steam Turbine, namely:
Back Pressure Turbine
Pass Out Turbine
Back Pressure Turbine
It is defined as, "When the exhaust steam from cogeneration of the turbine is utilized for process work".
We can modify initial steam pressure or exhaust pressure to get required steam of desired pressure and temp.
Process heater is running Above or At atmospheric pressure.
Ideally, we want 100% of heat extracted to transform steam into liquid .
Pump cannot work with 2 phase.
Pass Out Turbine
It is defined as, "The back pressure turbine through which a certain quantity of steam is continuously exhausted for the process heating at desired pressure and temp".
Process Heater ↦ has Higher Power-to-Heat ratio.
Feasibility Criteria ↦ Cost of generation, No utility present.
References:
Material from Class Lectures + Book named Power plant Engineering by P.K Nag (4th Edition) + My knowledge.
TAPING CORRECTIONS There are two types of corrections depending upon the type of errors in tape due to the different conditions. 1. Systematic Errors : Slope Erroneous tape length Temperature Tension Sag 2. Random Errors : Slope Alignment Marking & Plumbing Temperature Tension & Sag 1. Temperature Correction It is necessary to apply this correction, since the length of a tape is increased as its temperature is raised, and consequently, the measured distance is too small. It is given by the formula, C t = 𝛼 (T m – T o )L Where, C t = the correction for temperature, in m. 𝛼 = the coefficient of thermal expansion. T m = the mean temperature during measurement. T o = the tempe...
Solid Mechanics OR Mechanics of Materials OR Strength of Materials: It is the study of mechanics of body i.e. forces and their effects on deformable solids under different loading conditions. Deformable Body Mechanics: It is the study of non-rigid solid structures which deform under load. Deformation/Distortion ⇾ change of shape and size OR have some relative displacement or rotation of particles. It happens when we apply combined load. Rigid Body Motion ⇾ Translation or rotation of particles but having constant distance between particles. Since deformation occur at particular load. Below this load, every body is considered as rigid body . Types of Load: Point Load ⇾ Load apply on a single point i.e. concentrated load. Uniformly Distributed Load (UDL) ⇾ Load remains uniform throughout an area of element like beam. Varying Distributed Load (VDL) ⇾ Load varies with length with constant rate. Moment ⇾ It measures the tend...
Strain Transformation Principal Strain and stresses can occur in the same directions. Material Properties Relation (Young, bulk Rigidity Modulus) ⇼ Hooke's Law General State of Strain ⇼ Є X , Є Y , Є Z and ૪ X , ૪ Y , ૪ Z . Stress (normal or shear)/ Strain (normal or shear) ⇼ vary with element orientation. Transformation equations for Plane strain derived from: Interpretation of Experimental measurements Represent in graphical form for plane strain (Mohr's Circle). Geometry and independent of material properties. Mohr's Circle It is defined as., " A graphical method for determining normal and shear Shear stresses without using the stress transformation equations " . While considering the circle CCW ⇼ Shear strain positive upward & Normal strain positive towards right. The construction of Mohr's circle (with normal and shear stresses are known) is quite easy which include following steps: Draw a set o...
Comments
Post a Comment
HI, we wI'll contact you later