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How to temporary chill a car with non-working AC.



 
 
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  #51  
Old October 6th 04, 01:52 AM
Threeducks
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~^Johnny^~ wrote:
> On Sun, 26 Sep 2004 14:58:07 -0400, Threeducks > wrote:
>
>
>>Nope. There is no heat loss when you pass a fluid through a throttling
>>expansion, but there is a significant temperature drop. Now it's
>>becoming clear that you don't really understand how a refrigeration
>>cycle works.

>
>
>
> You mean expansion valves, orifices, tubes, and the like don't cause a
> negligible friction loss? :-)
>
> Shame on you! :-)
>
>
> All joking aside, throttling (metering) does indirectly cause a heat loss of
> fluid to air, as it forces condensation of the working fluid (latent heat),
> and there is resultant desuperheating and subcooling (sensible heat) involved
> as well.
>


You seem to be confused. The system of interest is a working fluid
passing from upstream of the orfice to downstream, not the rest of the
cycle. The change in enthalpy of a fluid as it passes through a valve
is zero and you can look that up in any thermodynamics textbook. The
energy contained within the fluid does not change as it passes through
the valve! Where would it go? How do you explain your concept of
"heat" in this context where we have a large temperature drop, but no
change in the amount of energy contained by the fluid?

The valve does not cause condensation, that is done in the condenser,
which is before you get to the valve. When you drop pressure with a
valve (or orfice), you vaporize part of the working fluid. How do you
expect to condense a fluid by reducing its pressure?

>
> [Now I'm gonna sound ridiculous, to prove a point:]


You've already sounded quite ridiculous. The only thing you've proven
is you know nothing about refrigeration.
Ads
  #52  
Old October 6th 04, 02:05 AM
Threeducks
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Posts: n/a
Default

~^Johnny^~ wrote:
> On Sun, 26 Sep 2004 14:31:59 GMT, wrote:
>
>
>> What's being argued here is the sematics of saying 'thermal
>>energy' vs 'heat energy', and while the former is perhaps more
>>correct, the later does perfectly well.

>
>
>
> It's rare that I find myself agreeing with Paul.
> But he has a point. While technically incorrect to refer to enthalpy as
> "heat", due to teh dynamic nature of heat, it is ridiculous to split hairs
> over semantics, as many textbooks use the two terms interchangeably.


No they don't. And it's not semantics. It's just wrong.

> Even the 1911 unabridged Webster's dictionary included both definitions for
> the term "heat", altough more modern dictionaries seem to have dropped the
> former.
>


I stick with what the rest of the thermodynamics community has agreed on
as the correct terminology.

> One can argue that since heat is *generated*, it has to be moving -- going
> somewhere -- therefore, it is a dynamic phenomenon. A change of enthalpy
> constitutes heating or cooling.


Or a change in pressure, or change in specific volume, or a change in
chemical composition, or chemical reaction. It is easy to have a change
in enthlapy without a change in temperature or a change in "heating and
cooling."

Explain where the "heat" goes when you pass HFC-134a through a valve.

> It was pointed out to me, that heat (even
> latent heat) can only move across a non-zero temperature gradient [thank you,
> Daestrom].
>


Don't get offended if I don't take you seriously, but if you just
learned this, you don't know diddly about what you're talking about.

> However, the concept of "heat" being synonymous with "enthalpy" is going to
> remain in the minds and textbooks of many, rightfully or wrongfully so, for
> many tears to come.


Which textbook? I have plenty of thermodynamics textbooks and none of
them say something so ridiculous.

> It's preposterous to go on and on and on about it, when
> it is clear that we are are really talking about the same thing.
>


It's not the same thing.

> You are all acting like a bunch of 10-year-olds!
>


Only because certain people don't know enough about thermodynamics to
know they don't know what they're talking about.

> This kind of reminds me of a classic Looney Tunes dialog:
>
> Bugs: I tell you it did!
> Sam: Did not!
> Bugs: Did, too!
> Sam: Did not!
> Bugs: Did, too!
> Sam: Did not!
> Bugs: Did, too!
> Sam: Did not!
> Bugs: Did, too!
> Sam: Did not!
> Bugs: Did not!
> Sam: Did, too!
> Bugs: Ok Doc, if you say so!
>
>

  #54  
Old October 6th 04, 06:25 PM
ray
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Posts: n/a
Default

gerry wrote:
>>I stick with what the rest of the thermodynamics community has agreed on
>>as the correct terminology.

>
>
> Humor: - Now try and get folks to stop using the term "silver solder"
> which was dumped by the alloy vendors and industry decades ago because it
> wasn't solder! There is material correctly called silver bearing solder
> and brazing material with silver content.
>
> gerry
>


or "standard transmission" instead of manual transmission.
I had to pay extra for a manual for my car.
My wife's car wasn't available with a stick... how could it be standard?

  #55  
Old October 7th 04, 03:21 AM
Sparky
external usenet poster
 
Posts: n/a
Default

~^Johnny^~ wrote:

> On Sun, 26 Sep 2004 14:31:59 GMT, wrote:
>
>
>> What's being argued here is the sematics of saying 'thermal
>>energy' vs 'heat energy', and while the former is perhaps more
>>correct, the later does perfectly well.

>
>
>
> It's rare that I find myself agreeing with Paul.
> But he has a point. While technically incorrect to refer to enthalpy as
> "heat", due to teh dynamic nature of heat, it is ridiculous to split hairs
> over semantics, as many textbooks use the two terms interchangeably.
> Even the 1911 unabridged Webster's dictionary included both definitions for
> the term "heat", altough more modern dictionaries seem to have dropped the
> former.
>
> One can argue that since heat is *generated*, it has to be moving -- going
> somewhere -- therefore, it is a dynamic phenomenon. A change of enthalpy
> constitutes heating or cooling. It was pointed out to me, that heat (even
> latent heat) can only move across a non-zero temperature gradient [thank you,
> Daestrom].
>
> However, the concept of "heat" being synonymous with "enthalpy" is going to
> remain in the minds and textbooks of many, rightfully or wrongfully so, for
> many tears to come. It's preposterous to go on and on and on about it, when
> it is clear that we are are really talking about the same thing.
>
> You are all acting like a bunch of 10-year-olds!
>
> This kind of reminds me of a classic Looney Tunes dialog:
>
> Bugs: I tell you it did!
> Sam: Did not!
> Bugs: Did, too!
> Sam: Did not!
> Bugs: Did, too!
> Sam: Did not!
> Bugs: Did, too!
> Sam: Did not!
> Bugs: Did, too!
> Sam: Did not!
> Bugs: Did not!
> Sam: Did, too!
> Bugs: Ok Doc, if you say so!


Excuse me, is this the argument clinic?
  #56  
Old October 7th 04, 04:13 AM
pjm@see_my_sig_for_address.com
external usenet poster
 
Posts: n/a
Default

On 7 Oct 2004 03:00:42 GMT, "Tegger®"
> wrote:

>Sparky > sprach im
. net:
>
>> ~^Johnny^~ wrote:
>>

>
>>> Bugs: I tell you it did!
>>> Sam: Did not!
>>> Bugs: Did, too!
>>> Sam: Did not!
>>> Bugs: Did, too!
>>> Sam: Did not!
>>> Bugs: Did, too!
>>> Sam: Did not!
>>> Bugs: Did, too!
>>> Sam: Did not!
>>> Bugs: Did not!
>>> Sam: Did, too!
>>> Bugs: Ok Doc, if you say so!

>>
>> Excuse me, is this the argument clinic?

>
>
>
>
>If you want an argument you have to pay a dollar.


Does not.



Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'

HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/
  #57  
Old October 8th 04, 06:07 AM
Sparky
external usenet poster
 
Posts: n/a
Default

Tegger® wrote:

> Sparky > sprach im
> et:
>
>
>>~^Johnny^~ wrote:

>
>>>Bugs: I tell you it did!
>>>Sam: Did not!
>>>Bugs: Did, too!
>>>Sam: Did not!
>>>Bugs: Did, too!
>>>Sam: Did not!
>>>Bugs: Did, too!
>>>Sam: Did not!
>>>Bugs: Did, too!
>>>Sam: Did not!
>>>Bugs: Did not!
>>>Sam: Did, too!
>>>Bugs: Ok Doc, if you say so!

>>
>>Excuse me, is this the argument clinic?

>
> If you want an argument you have to pay a dollar.


But you're arguing with me, therefore I must have paid you. There, I've
run rings around your logic!


  #58  
Old October 8th 04, 06:22 AM
pjm@see_my_sig_for_address.com
external usenet poster
 
Posts: n/a
Default

On Fri, 08 Oct 2004 05:07:32 GMT, Sparky > wrote:

>Tegger® wrote:
>
>> Sparky > sprach im
>> et:
>>
>>
>>>~^Johnny^~ wrote:

>>
>>>>Bugs: I tell you it did!
>>>>Sam: Did not!
>>>>Bugs: Did, too!
>>>>Sam: Did not!
>>>>Bugs: Did, too!
>>>>Sam: Did not!
>>>>Bugs: Did, too!
>>>>Sam: Did not!
>>>>Bugs: Did, too!
>>>>Sam: Did not!
>>>>Bugs: Did not!
>>>>Sam: Did, too!
>>>>Bugs: Ok Doc, if you say so!
>>>
>>>Excuse me, is this the argument clinic?

>>
>> If you want an argument you have to pay a dollar.

>
>But you're arguing with me, therefore I must have paid you. There, I've
>run rings around your logic!
>
>


Gee, I never saw a micro-ring before ....



Paul ( pjm @ pobox . com ) - remove spaces to email me
'Some days, it's just not worth chewing through the restraints.'

HVAC/R program for Palm PDA's
Free demo now available online http://pmilligan.net/palm/
Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/
  #59  
Old October 8th 04, 10:36 PM
~^Johnny^~
external usenet poster
 
Posts: n/a
Default

On Tue, 05 Oct 2004 20:52:58 -0400, Threeducks > wrote:

>~^Johnny^~ wrote:
>> On Sun, 26 Sep 2004 14:58:07 -0400, Threeducks > wrote:
>>
>>
>>>Nope. There is no heat loss when you pass a fluid through a throttling
>>>expansion, but there is a significant temperature drop. Now it's
>>>becoming clear that you don't really understand how a refrigeration
>>>cycle works.

>>
>>
>>
>> You mean expansion valves, orifices, tubes, and the like don't cause a
>> negligible friction loss? :-)
>>
>> Shame on you! :-)
>>
>>
>> All joking aside, throttling (metering) does indirectly cause a heat loss of
>> fluid to air, as it forces condensation of the working fluid (latent heat),
>> and there is resultant desuperheating and subcooling (sensible heat) involved
>> as well.
>>

>
>You seem to be confused. The system of interest is a working fluid
>passing from upstream of the orfice to downstream, not the rest of the
>cycle.


Uh, I was being facetious.
Believe me, I am NOT confused.

I led. I am confused about your post! :-)



>The change in enthalpy of a fluid as it passes through a valve
>is zero and you can look that up in any thermodynamics textbook.


Of course. Ignoring friction losses.
Of course, I was being a smartass.
I am having fun! Are you?


>The
>energy contained within the fluid does not change as it passes through
>the valve! Where would it go?


=Whooosh!= It sailed right over your head, my friend.
I was intentionally splitting hairs. You can't argue against friction loss!
When a fluid flows through a capillary tube, there is (almost) sunstantial
friction loss! And with a TXV or TEV, there is turbulence, possible
cavitation, etc.


>How do you explain your concept of
>"heat" in this context where we have a large temperature drop, but no
>change in the amount of energy contained by the fluid?
>
>The valve does not cause condensation, that is done in the condenser,
>which is before you get to the valve. When you drop pressure with a
>valve (or orfice), you vaporize part of the working fluid. How do you
>expect to condense a fluid by reducing its pressure?
>
>>
>> [Now I'm gonna sound ridiculous, to prove a point:]

>
>You've already sounded quite ridiculous. The only thing you've proven
>is you know nothing about refrigeration.



Bull****.

YHBT, YL
(You have been trolled, you lost).

I have designed and built numerous systems for a living.
What have YOU done? Flame me? **** you.

Go soak your head.








--
-john
wide-open at throttle dot info
 




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