Steam turbines, maximum amount of work done?

AI Thread Summary
The discussion revolves around calculating the maximum work output of a steam turbine with an input temperature of 800°C and an exhaust temperature of 150°C. Participants suggest using the Carnot engine concept to derive the maximum work done, represented by the formula W = 0.6Q, where Q is the heat input. Clarification is provided that "for a given heat input Q" means to leave Q as a variable in the final answer rather than substituting a specific value. The conversation highlights the importance of understanding thermodynamic principles in relation to steam turbines. Overall, the focus is on determining the conditions under which maximum work is achieved.
pp84
Messages
4
Reaction score
0
Steam turbines, maximum amount of work done?

Hi, having a little trouble with this problem, not entierly sure what formula to use, or what value to use for Q.

A steam turbine is operated ith an input temp of 800C and exhaust temp of 150C. What is the maximum amount of work the turbine can do for a given heat input Q? Under what conditions is the maximum achieved?

Thanks in advance
 
Physics news on Phys.org
have you tried thinking of the thing as a carnot engine?
 
yeh i have but that would just give me an answer with two undefined variables.

0.6Q=W

in the question it says 'for a given heat input Q' what does that mean exactly, could it mean pick a random value.

Thanks for your reply
 
it means just leave Q in your answer. you've already got it
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
View full post »

Thread 'Struggling to understand the concept of the question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

What are the thermodynamic properties and efficiency of a steam plant?
Replies
9
Views
2K
Internal energy of a container filled with water & steam
Replies
12
Views
2K
Wind Turbine Blade Experiment: What is the Optimal Number for Maximum Voltage?
Replies
2
Views
4K
Thermodynamics Regenerative Rankine Cycle
Replies
4
Views
2K
Calculating Revenue for a Geothermal Power Plant with 150kW Steam Flow at 180°C
Replies
5
Views
2K
Steam driven turbine: Heat, Power, evaporation
Replies
2
Views
3K
Reversible Isothermal Expansion Steam
Replies
2
Views
3K
Can a turbo expander convert more heat to work than a piston expander?
Replies
2
Views
1K
Calculating Efficiency of a Steam Turbine at Varying Temperatures
Replies
9
Views
2K
Limiting factor in design of small gas turbine w/ LOW self sustain speed
Replies
5
Views
2K

Hot Threads

Recent Insights

Back
Top