UI Steam Plant Boiler Analysis MICHAEL CLARKBRIAN KISLING COLIN SOWARDSVINCE SCHWARTZ.
-
Upload
lesley-wood -
Category
Documents
-
view
216 -
download
2
Transcript of UI Steam Plant Boiler Analysis MICHAEL CLARKBRIAN KISLING COLIN SOWARDSVINCE SCHWARTZ.
UI Steam Plant Boiler AnalysisMICHAEL CLARK BRIAN KISLING
COLIN SOWARDS VINCE SCHWARTZ
Goals•Synthesize given information
•Simplify the problem into reasonable terms/ideas
•Apply reasonable assumptions
•Keep records of all calculations
•Find Overall Heat Transfer Coefficient
•Find Heat Rate
•Assess possible performance improving options
Our Initial Model
T_in = 266 F x_in = 0P = 164.7 psiam_dot = 40800 lbm/hr
T_out = 365.9 Fx_out = 1
= 39,200,000 Btu/hr
Assumptions•Model the water/steam as pure (negate impurities)
•Flue Gas modeled as Air
•Steady State
•Boiler modeled as an adiabatic heat exchanger
•All pipes are equal diameter and have equal amounts of fouling on them
•Crossflow
Finding the Initial Q-ValueUse EES to calculate enthalpies
eq. 11.7a
= 39.2 MMBtu
Finding the T_inf-Valueeq. 11.6a
Setting the q’s equal to each other, and solving for the mass flow rate of the flue gas, the flue gas temperature can be backed out using the EES function call.
Analysis of the Pipes in the Boiler•1764 pipes• D_outside = 1.5 in• D_inside = 1.25 in• Mild steel
•Cross flow
•7 pipes per side
•Thermal Circuit
T_inf h_inf
Find the Convective Heat Transfer Coeff. (Outside & Inside)
Assume a constant pipe surface temperature
Find Necessary Pi-groups◦ Reynolds◦ Nusselt◦ Prandtl
eq. 7.53
(Laminar Flow) eq. 8.55
Thermal Circuit
Final AssessmentInitial boiler efficiency was thought to be around 76-78%
Our calculations put the boiler at a 77.8% efficiency
Overall Heat Transfer Coefficient;◦ U = 5.009 [Btu/hr-ft^2-R]
Rate of Heat Transfer◦ Q = 50.36 [MMBtu/hr]
Recommendations Replace the whole thing?
◦ NOPE◦ Too expensive◦ Would only improve the efficiency a minimal amount
Average commercial boilers tend to hover around 70% - 85% efficiency◦ Expensive boiler component additions would only
minimally increase overall efficiency
B.E.T Tube Cleaners◦ Increase boiler efficiency from 6% - 20%◦ Uses hourly compressed air/steam jets to clean pipes
Credit: fuelefficiencyllc.com
Questions/Comments/Critiques/Compliments•No questions
•No comments
•ABSOLUTELY no critiques• We’re all friends here, right?
•Just compliments