`R/m325traceline.R`

`m325traceline.Rd`

Trace values of thermal-hydraulic regime (temperature, pressure, consumption) along the adjacent linear segments of pipeline using norms of heat flux values prescribed by Minenergo Order 325.

```
m325traceline(
temperature = 130,
pressure = mpa_kgf(6),
consumption = 250,
g = 0,
d = 700,
len = c(600, 530, 300, 350),
year = 1986,
insulation = 0,
laying = "underground",
beta = FALSE,
exp5k = TRUE,
roughness = 0.006,
inlet = 0,
outlet = 0,
elev_tol = 0.1,
method = "romeo",
forward = TRUE,
absg = TRUE
)
```

- temperature
temperature of heat carrier (water) inside the pipe sensor-measured at the inlet (forward tracing) or at the outlet (backward tracing) of path, [

*°C*]. Type:`assert_number`

.- pressure
absolute pressure of heat carrier (water) sensor-measured at the inlet (forward tracing) or at the outlet (backward tracing) of path, [

*MPa*]. Type:`assert_number`

.- consumption
amount of heat carrier (water) sensor-measured at the inlet (forward tracing) or at the outlet (backward tracing) of path, [

*ton/hour*]. Type:`assert_number`

.- g
amount of heat carrier discharge to network for each pipe segment in the tracing path enumerated along the direction of flow. If flag

`absg`

is`TRUE`

then they treat argument`g`

as absolute value in [*ton/hour*], otherwise they do as percentage of consumption in the pipe segment. Type:`assert_double`

.- d
internal diameters of subsequent pipes in tracing path that are enumerated along the direction of flow, [

*mm*]. Type:`assert_double`

.- len
length of subsequent pipes in tracing path that are enumerated along the direction of flow, [

*m*]. Type:`assert_double`

.- year
year when pipe is put in operation after laying or total overhaul for each pipe in tracing path enumerated along the direction of flow. Type:

`assert_integerish`

.- insulation
insulation that covers the exterior of pipe:

`0`

no insulation

`1`

foamed polyurethane or analogue

`2`

polymer concrete

for each pipe in tracing path enumerated along the direction of flow. Type:

`assert_numeric`

and`assert_subset`

.- laying
type of pipe laying depicting the position of pipe in space:

`air`

`channel`

`room`

`tunnel`

`underground`

for each pipe in tracing path enumerated along the direction of flow. Type:

`assert_character`

and`assert_subset`

.- beta
should they consider additional heat losses of fittings? Logical value for each pipe in tracing path enumerated along the direction of flow. Type:

`assert_logical`

.- exp5k
pipe regime flag: is pipe operated more that

`5000`

hours per year? Logical value for each pipe in tracing path enumerated along the direction of flow. Type:`assert_logical`

.- roughness
roughness of internal wall for each pipe in tracing path enumerated along the direction of flow, [

*m*]. Type:`assert_double`

.- inlet
elevation of pipe inlet for each pipe in tracing path enumerated along the direction of flow, [

*m*]. Type:`assert_double`

.- outlet
elevation of pipe outlet for each pipe in tracing path enumerated along the direction of flow, [

*m*]. Type:`assert_double`

.- elev_tol
maximum allowed discrepancy between adjacent outlet and inlet elevations of two subsequent pipes in the traced path, [

*m*]. Type:`assert_number`

.- method
method of determining

*Darcy friction factor*`romeo`

`vatankhan`

`buzelli`

Type:

`assert_choice`

. For more details see`dropp`

.- forward
tracing direction flag: is it a forward direction of tracing? If

`FALSE`

the backward tracing is performed. Type:`assert_flag`

.- absg
Whether argument

`g`

(amount of heat carrier discharge to network) is an absolute value in [*ton/hour*] (`TRUE`

) or is it a percentage of consumption in the pipe segment (`FALSE`

)? Type:`assert_flag`

.

named list of regime parameters for the traced path with the next elements:

`temperature`

calculated temperatures of heat carrier for all pipeline segments, [

*°C*]. Type:`assert_double`

.`pressure`

calculated pressures of heat carrier for all pipeline segments, [

*MPa*]. Type:`assert_double`

.`consumption`

calculated consumption(s) of heat carrier for all pipeline segments, [

*ton/hour*]. Type:`assert_double`

.

The calculated (values of) regime may be considered as representation of district heating process in conditions of hypothetically perfect technical state of pipe walls and insulation.

They consider only simple tracing paths which do not contain rings and any kind of parallelization. At the same time bidirectional (forward and backward) tracing is possible in accordance with sensor position. They also may consider discharges to network at the inlet of each pipeline segment as an approximation of actual forks of flows. Relevant illustration of adopted assumptions for 4-segment tracing path is depicted on the next figure.

They make additional check for consistency of `inlet`

and `outlet`

values for subsequent pipe segments. Discrepancy of appropriate elevations
cannot be more than `elev_tol`

.

`m325dropt`

for calculating normative temperature drop in
single pipeline segment

Other Regime tracing:
`m325tracebwm()`

,
`m325tracebw()`

,
`m325tracefw()`

```
# Consider 4-segment tracing path depicted in ?m325regtrace help page.
# First, let sensor readings for forward tracing:
t_fw <- 130 # [°C]
p_fw <- .588399*all.equal(.588399, mpa_kgf(6)) # [MPa]
g_fw <- 250 # [ton/hour]
# Let discharges to network for each pipeline segment are somehow determined as
discharges <- seq(0, 30, 10) # [ton/hour]
# \donttest{
# Then the calculated regime (red squares) for forward tracing is
regime_fw <- m325traceline(t_fw, p_fw, g_fw, discharges, forward = TRUE)
print(regime_fw)
#> $temperature
#> [1] 129.1799 128.4269 127.9628 127.3367
#>
#> $pressure
#> [1] 0.5878607 0.5874226 0.5872143 0.5870330
#>
#> $consumption
#> [1] 250 240 220 190
#>
# $temperature
# [1] 129.1799 128.4269 127.9628 127.3367
#
# $pressure
# [1] 0.5878607 0.5874226 0.5872143 0.5870330
#
# $consumption
# [1] 250 240 220 190
# }
# Next consider values of traced regime as sensor readings for backward tracing:
t_bw <- 127.3367 # [°C]
p_bw <- .5870330 # [MPa]
g_bw <- 190 # [ton/hour]
# Then the calculated regime (red squares) for backward tracing is
# \donttest{
regime_bw <- m325traceline(t_bw, p_bw, g_bw, discharges, forward = FALSE)
print(regime_bw)
#> $temperature
#> [1] 129.9953 129.1769 128.4254 127.9619
#>
#> $pressure
#> [1] 0.5883998 0.5878611 0.5874228 0.5872144
#>
#> $consumption
#> [1] 250 250 240 220
#>
# $temperature
# [1] 129.9953 129.1769 128.4254 127.9619
#
# $pressure
# [1] 0.5883998 0.5878611 0.5874228 0.5872144
#
# $consumption
# [1] 250 250 240 220
# Let compare sensor readings with backward tracing results:
tracing <- with(regime_bw, {
lambda <- function(val, constraint)
c(val, constraint, constraint - val,
abs(constraint - val)*100/constraint)
first <- 1
structure(
rbind(
lambda(temperature[first], t_fw),
lambda(pressure[first], p_fw),
lambda(consumption[first], g_fw)
),
dimnames = list(
c("temperature", "pressure", "consumption"),
c("sensor.value", "traced.value", "abs.discr", "rel.discr")
)
)
})
print(tracing)
#> sensor.value traced.value abs.discr rel.discr
#> temperature 129.9952943 130.000000 4.705723e-03 0.0036197868
#> pressure 0.5883998 0.588399 -8.290938e-07 0.0001409067
#> consumption 250.0000000 250.000000 0.000000e+00 0.0000000000
# sensor.value traced.value abs.discr rel.discr
# temperature 130.000000 129.9952943 4.705723e-03 0.0036197868
# pressure 0.588399 0.5883998 -8.290938e-07 0.0001409067
# consumption 250.000000 250.0000000 0.000000e+00 0.0000000000
# }
```