Need advice. Failing 2 Classes.

comicho
Tue, 30 Oct 2012 23:37:18 +0000

I’m majoring in Petroleum Engineering. Currently taking differential equations, organic chemistry, engineering thermodynamics, and applied drilling engineering. I am practically failing thermo and ochem. I have 1 test left in both classes and a final.

I spend hours literally just sitting there flipping pages going back and forth trying to read anything that might make sense of the problems presented to me but it’s just not clicking in my head. Seriously what are some ways to get better? I am considering just hand-writing all the chapters, but I doubt that will help at all. I need some tips, anything at all… I’m getting desperate and beginning to feel like this might be the semester that finally gets me.

I feel like I spend hours not getting anywhere and never really getting it. Let me post an example of what I was working on today:

"Consider the “safety” of the following situation. A chemical plant has eight identical spherical high-pressure
gas storage tanks, each fabricated of 6000 kg of stainless steel with identical pressure relief valves and tall
vent stacks. The tanks store hydrogen gas (H2), oxygen gas (O2), methane gas (CH4) and argon gas (Ar) as
needed. The tanks are normally filled to capacity at a pressure of 2000 kPa and a temperature of 300 K. The
tank pipe flanges or the entire tank may burst if pressure exceeds 3000 kPa or temperature exceeds 1000 K.
Each tank has a pressure relief valve that must prevent damage during a “worst case accident”, defined as the
tanks being full at 2000 kPa and 300 K, when a fire occurs on the site, coupled with a failure of the emergency
sprinkler system. The fire causes a steady heat transfer rate of 9000 kJ/s to each of the tanks. Emergency
fire crews are expected to arrive, isolate and cool the tanks after a delay of 5 minutes to respond. The relief
valves must meet the following specifications to prevent a failure during the initial 5 minute (300 second)
interval following the start of the fire.

1. vent the gas at a rate sufficient to prevent the tank pressure from exceeding 3000 kPa

2. vent the gas at a rate sufficient to prevent the tank temperature from exceeding 1000 K
The tanks were originally set-up to only store hydrogen gas (H2), and the relief
valves meet the safety specifications if the tanks are filled with hydrogen gas.
However, the relief valves have not been certified for venting the other gases now
stored in the tanks. Determine if the relief valves are adequate by using
TRANSIENT CONTROL VOLUME ANALYSIS and an APPROXIMATE
INCREMENTAL NUMERICAL SIMULATION to estimate tank pressure,
temperature and mass for the 300 second interval of the “worst case” conditions."

I’m given a ***** ton of conditions… but just DON’T GET IT. I literally drew an entire picture that looks like a painting for the movie of backdraft, manipulate every equation i can think of pertaining to this, and finally gave up after so many hours because now I have ochem. I just need a little encouragement or advice I guess…

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