m278hlair: Minenergo-278. Heat losses of overhead pipeline segment

In pipenostics: Diagnostics, Reliability and Predictive Maintenance of Pipeline Systems

Description

Calculate values of heat flux emitted by overhead pipeline segment (surrounded by air) 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.

Usage

m278hlair(
  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 = 26,
  len = 1,
  duration = 1
)

Arguments

t1	temperature of heat carrier (water) inside the supplying pipe, [°C]. Type: assert_double.
t2	temperature of heat carrier (water) inside the returning pipe, [°C]. Type: assert_double.
t0	temperature of environment, [°C]. In case of overhead laying this is the ambient temperature. Type: assert_double.
insd1	thickness of the insulator which covers the supplying pipe, [m]. Type: assert_double.
insd2	thickness of the insulator which covers the returning pipe, [m]. Type: assert_double.
d1	external diameter of supplying pipe, [m]. Type: assert_double.
d2	external diameter of returning pipe, [m]. Type: assert_double.
lambda1	thermal conductivity of insulator which covers the supplying pipe [W/m/°C]. Type: assert_double.
lambda2	thermal conductivity of insulator which covers the returning pipe [W/m/°C]. assert_double.
k1	technical condition factor for insulator of supplying pipe, []. Type: assert_double.
k2	technical condition factor for insulator of returning pipe, []. Type: assert_double.
lambda0	thermal conductivity of environment, [W/m/°C]. In case of overhead laying this is the thermal conductivity of open air. Type: assert_double.
len	length of pipeline segment, [m]. Type: assert_double.
duration	duration of heat flux emittance, [hour]. Type: assert_double.

Details

Details on using k1 and k2 are the same as for m278hlcha.

Value

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.

See Also

Other Minenergo: m278hlcha(), m278hlund(), m278insdata, m278inshcm(), m278soildata, m325beta(), m325dropt(), m325nhldata, m325nhl(), m325testbench

Examples

 m278hlair()
 # [1] 138.7736

pipenostics documentation built on March 2, 2021, 5:06 p.m.