|LoFi version for PDAs||Help Search Members Calendar|
|Welcome Guest ( Log In | Register )||Resend Validation Email|
Posted: Jun 11 2007, 11:02 AM
Joined: 3-July 06
Positive Feedback: 100%
Feedback Score: 7
The question states:
Show that if the Kelvin Planck statement of the 2nd law were not true,a violation of the Clausius statement would be possible.
My attempts:(Please confirm if I am correct)
Kelvin Planck statement says that it is impossible for any system to operate in thermodynamic cycle and deliver a net amount of work to its surroudnings while receiving energy by heat transfer from a single thermal reservoir.
Qcool>0 and efficiency <1
Kelvin Planck statement is not true because you can't the net amount of work to its surroundings while receiving energy by heat transfer from a single thermal reservoir.
we know the second law of thermodyanics cycle is that you have hot reservior and cool reservoir. and you can have work output from the hot reservoir by extract heat from and reject heat to cool reservoir.
W_net=Q_h - Q_c
Posted: Jun 13 2007, 04:56 AM
Group: Power Member
Joined: 31-March 06
Positive Feedback: 96.83%
Feedback Score: 143
I don't think this one is quite right.
Start with the KP statement, and assume that you can convert Q at temp TL directly to W without any other heat source. Now use this W to power a heat pump which moves QL from TL to TH. Consider the whole thing to be a heat pump. Then with no external work input, the net effect is to move Q+QL from TL to TH.
Hope this helps!
A hallmark of intelligence is the ability to give precise answers to vague questions.