|
|
Forgive me for being slow here, but there are quite a few more lines on this graph than I'm used to. Does this graph say that as the head pressure rises to 100ft, it raises the water temp by about 40 degree,and yet uses nearly 10HP to do it?
Content-Type: multipart/alternative;
boundary="----=_NextPart_001_0A85_01C39682.B1BBDDE0"
------=_NextPart_001_0A85_01C39682.B1BBDDE0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Here is a .GIF that illustrates both our points. At zero flow, the pump =
shaft horsepower is less than at rated flow, but all the energy is going =
into heating the water.
I believe that the reason Davies Craig claims that they save a lot of =
horsepower, is because at high rpm, the pump is not running at its high =
efficiency point. It is clear from the successful EWP tests of Todd, =
that the actual energy required to pump the water is small. So if DC is =
correct, then they are using the high rpm point for the "horsepower =
saved".
Bill Schertz
Tracy Wrote:
All true. But my point was that there is still *less* shaft HP =
required to turn the pump when the thermostat restricts the flow through =
the pump and we are not wasting engine HP by having a restriction in the =
circuit as is occasionally claimed. True, the pump is operating in a =
less efficient part of its operating curve, but do we really care?
Tracy
------=_NextPart_001_0A85_01C39682.B1BBDDE0
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD><TITLE></TITLE>
<META http-equiv=3DContent-Type content=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 5.50.4611.1300" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2>Here is a .GIF that illustrates both =
our points. At=20
zero flow, the pump shaft horsepower is less than at rated flow, but all =
the=20
energy is going into heating the water.</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>I believe that the reason Davies Craig =
claims that=20
they save a lot of horsepower, is because at high rpm, the pump is not =
running=20
at its high efficiency point. It is clear from the successful EWP tests =
of Todd,=20
that the actual energy required to pump the water is small. So if DC is =
correct,=20
then they are using the high rpm point for the "horsepower =
saved".</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>Bill Schertz</FONT></DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial"><FONT face=3DArial size=3D2>Tracy=20
Wrote:</FONT></DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV>
<DIV><FONT face=3DArial size=3D2>All true. But my point was =
that there is=20
still *less* shaft HP required to turn the pump when the thermostat=20
restricts the flow through the pump and we are not wasting engine HP =
by=20
having a restriction in the circuit as is occasionally =
claimed. True,=20
the pump is operating in a less efficient part of its operating =
curve, but=20
do we really care?</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial=20
size=3D2>Tracy</FONT></DIV></DIV></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>=
------=_NextPart_001_0A85_01C39682.B1BBDDE0--
>> Homepage: http://www.flyrotary.com/
>> Archive: http://lancaironline.net/lists/flyrotary/List.html
|
|