Description Usage Arguments Details Value See Also Examples
Calculate values of heat flux emitted by underground pipeline segment which is not mounted in channel as a function of construction, operation, and technical condition specifications according to Appendix 5.1 of Minenergo Method 278.
This type of calculations is usually made on design stage of district heating network (where water is a heat carrier) and is closely related to building codes and regulations.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | m278hlund(
t1 = 110,
t2 = 60,
t0 = 5,
insd1 = 0.1,
insd2 = insd1,
d1 = 0.25,
d2 = d1,
lambda1 = 0.09,
lambda2 = 0.07,
k1 = 1,
k2 = k1,
lambda0 = 1.74,
z = 2,
s = 0.55,
len = 1,
duration = 1
)
|
t1 |
temperature of heat carrier (water) inside the supplying pipe, [°C].
Type: |
t2 |
temperature of heat carrier (water) inside the returning pipe, [°C].
Type: |
t0 |
temperature of environment, [°C]. In case of underground laying this is
the temperature of subsoil. Type: |
insd1 |
thickness of the insulator which covers the supplying pipe, [m].
Type: |
insd2 |
thickness of the insulator which covers the returning pipe, [m].
Type: |
d1 |
external diameter of supplying pipe, [m]. Type: |
d2 |
external diameter of returning pipe, [m]. Type: |
lambda1 |
thermal conductivity of insulator which covers the supplying pipe
[W/m/°C]. Type: |
lambda2 |
thermal conductivity of insulator which covers the returning pipe
[W/m/°C]. Type: |
k1 |
technical condition factor for insulator of supplying pipe, [].
Type: |
k2 |
technical condition factor for insulator of returning pipe, [].
Type: |
lambda0 |
thermal conductivity of environment, [W/m/°C]. In case of underground
laying this is the thermal conductivity of subsoil.
Type: |
z |
underground laying depth, [m].
Type: |
s |
distance between supplying and returning pipes, [m].
Type: |
len |
length of pipeline segment, [m].
Type: |
duration |
duration of heat flux emittance, [hour].
Type: |
Details on using k1
and k2
are the same as for
m278hlcha
.
Heat flux emitted by pipeline segment during duration
, [kcal].
If len
of pipeline segment is 1 m and duration
of
heat flux emittance is set to 1 hour then the return value is equal
to that in [kcal/m/h] units and so comparable with values of
heat flux listed in
Minenergo Order 325.
Type: assert_double
.
Other Minenergo:
m278hlair()
,
m278hlcha()
,
m278insdata
,
m278inshcm()
,
m278soildata
,
m325beta()
,
m325dropt()
,
m325nhldata
,
m325nhl()
,
m325testbench
1 2 | m278hlund()
# [1] 102.6226
|
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