5 2 |
Bosch Geothermal Heat Pumps
Bosch Thermotechnology Corp.
Data subject to change
Applications Manual
When discussing pipe properties, typical thermal
resistances for four common pipe sizes can be considered
(although 1-½" pipe is now becoming more dif cult to
nd) (Table 25). Avoiding laminar ow at design conditions
is important to provide good heat transfer. Similar tables
exist for various other types of piping.
Using the referenced table, for water, the ow rate should
be at least 2.0 GPM for ¾" through 1-¼" pipe, and at least
3 GPM for 1-½" pipe to avoid laminar ow
Pipe Thermal Resistance Based On Borehole Cuttings For Back lling Around U-Tube
U-Tube Dia.
SDR or
Schedule
Pipe (Bore) Thermal Resistance (h•ft•°F/Btu)
For water
ows above
2.0 US gpm
20% Prop.
Glycol Flow
3.0 US gpm
20% Prop.
Glycol Flow
5.0 US gpm
20% Prop.
Glycol Flow
10.0 US gpm
¾
in. (0.15 ft)
SDR 11
0.09
0.12
NR
NR
SDR 9
0.11
0.15
NR
NR
Sch 40
0.10
0.14
NR
NR
1.0 in. (0.18 ft)
SDR 11
0.09
0.14
0.10
NR
SDR 9
0.11
0.16
0.12
NR
Sch 40
0.10
0.15
0.11
NR
1
¼
in. (0.22 ft)
SDR 11
0.09
0.15
0.12
0.09
SDR 9
0.11
0.17
0.15
0.11
Sch 40
0.09
0.15
0.12
0.09
1
½
in.
(0.25 ft)
SDR 11
0.09¹
0.16
0.15
0.09
SDR 9
0.11¹
0.18
0.17
0.11
Sch 40
0.08¹
0.14
0.14
0.08
Tab.25 Pipe Thermal resistance
Courtesy of American Society of Heating, Air-conditioning and
Refrigeration Engineers Inc., www.ashrae.org.
¹ Water ow must be at least 3.0 US gpm to avoid laminar ow for these
cases.
Содержание Geothermal Heat Pumps
Страница 1: ...Bosch Geothermal Heat Pumps For Residential Applications Applications Manual ...
Страница 2: ...2 Bosch Geothermal Heat Pumps Bosch Thermotechnology Corp Data subject to change Applications Manual ...
Страница 126: ...126 Bosch Geothermal Heat Pumps Bosch Thermotechnology Corp Data subject to change Applications Manual ...
Страница 127: ...Applications Manual Bosch Geothermal Heat Pumps 127 Bosch Thermotechnology Corp Data subject to change ...