Massively trace forwards thermal-hydraulic regime for district heating network

Trace values of thermal-hydraulic regime (temperature, pressure, flow rate, and other) in the bunched pipeline along the flow direction using user-provided values of specific heat loss power.

Usage

tracefw(
  sender = c(0, 1),
  acceptor = c(1, 2),
  temperature = c(70, NA_real_),
  pressure = c(0.588399, NA_real_),
  flow_rate = c(20, NA_real_),
  d = c(100, 100),
  wth = c(8, 8),
  len = c(72.446, 72.446),
  loss = c(78.4, 78.4),
  roughness = c(0.001, 0.001),
  inlet = c(0.5, 1),
  outlet = c(1, 1),
  elev_tol = 0.1,
  method = "romeo",
  verbose = TRUE,
  csv = FALSE,
  file = "tracefw.csv",
  use_cluster = FALSE
)

Arguments

sender

identifier of the node which heat carrier flows out. Type: any type that can be painlessly coerced to character by as.character.

acceptor

identifier of the node which heat carrier flows in. According to topology of test bench considered this identifier should be unique for every row. Type: any type that can be painlessly coerced to character by as.character.

temperature

sensor-measured temperature of heat carrier (water) sensor-measured on the root node, [°C]. Use NA_float_s for nodes without temperature sensor. Type: assert_double.

pressure

sensor-measured absolute pressure of heat carrier (water) inside the pipe on the root node, [MPa]. Use NA_float_s for nodes without pressure sensor. Type: assert_double.

flow_rate

sensor-measured amount of heat carrier (water) on root node that is transferred by pipe during a period, [ton/h]. Type: assert_double. Use NA_float_s for nodes without flow rate sensor.

d

outside diameter of pipe (i.e.diameter of acceptor's incoming edge), [mm]. Type: assert_double.

wth

wall thickness of pipe, [mm]. Type: assert_double.

len

pipe length (i.e. length of acceptor's incoming edge), [m]. Type: assert_double.

loss

user-provided value of specific heat loss power for each pipe in tracing path, [kcal/m/h]. Values of the argument can be obtained experimentally, or taken from regulatory documents. Type: assert_double.

roughness

roughness of internal wall of pipe (i.e. acceptor's incoming edge), [m]. Type: assert_double.

inlet

elevation of pipe inlet, [m]. Type: assert_double.

outlet

elevation of pipe outlet, [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
vatankhah
buzzelli

Type: assert_choice. For more details see dropp.

verbose

logical indicator: should they watch tracing process on console? Type: assert_flag.

csv

logical indicator: should they incrementally dump results to csv- file while tracing? Type: assert_flag.

file

name of csv-file which they dump results to. Type: assert_character of length 1 that can be used safely to create a file and write to it.

use_cluster

utilize functionality of parallel processing on multi-core CPU. Type: assert_flag.

Value

data.frame containing results (detailed log) of tracing in narrow format:

node: Tracing job. Identifier of the node which regime parameters is calculated for. Values in this vector are identical to those in argument acceptor. Type: assert_character.
tracing: Tracing job. Identifiers of nodes from which regime parameters are traced for the given node. Identifier sensor is used when values of regime parameters for the node are sensor readings. Type: assert_character.
backward: Tracing job. Identifier of tracing direction. It constantly equals to FALSE. Type: assert_logical.
aggregation: Tracing job. Identifier of the aggregation method associated with traced values. For forward tracing the only option is identity. Type: assert_character.
loss: Traced thermal hydraulic regime. Normative specific heat loss power of adjacent pipe, [kcal/m/h]. Type: assert_double.
flux: Traced thermal hydraulic regime. Normative heat flux of adjacent pipe, [W/m²]. Type: assert_double.
Q: Traced thermal hydraulic regime. Normative heat loss of adjacent pipe per day, [kcal]. Type: assert_character.
temperature: Traced thermal hydraulic regime. Traced temperature of heat carrier (water) that is associated with the node, [°C]. Type: assert_double.
pressure: Traced thermal hydraulic regime. Traced pressure of heat carrier (water) that is associated with the node, [MPa]. Type: assert_double.
flow_rate: Traced thermal hydraulic regime. Traced flow rate of heat carrier (water) that is associated with the node, [ton/h]. Type: assert_double.
job: Tracing job. Value of tracing job counter. For forward tracing value of job counts the number of traced paths from root node. Type: assert_count.

Type: assert_data_frame.

Details

They consider the topology of district heating network represented by m325nxdata:

Tracing starts from sensor-equipped root node and goes forward, i.e along the flow direction. Function traceline serves under the hood for tracing identified linear segments from root node to every terminal node. Hence they only need root node to be equipped with sensors. Sensors at other nodes are redundant in forward tracing, since the tracing algorithm by no means consider them for tracing.

Moreover in the forward tracing algorithm they assume the flow of heat carrier is distributed proportionally to the cross-sectional area of the outgoing pipeline. Actually, a lot of reasons may cause significant deviations from this assumption. As a result, the sequence of paired backward/forward tracing may be divergent for regime parameters.

Though some input arguments are natively vectorized their individual values all relate to common part of district heating network, i.e. associated with common object. It is due to isomorphism between vector representation and directed graph of this network. For more details of isomorphic topology description see m325nxdata.

They are welcome to couple the algorithm with functionality of data.table.

Examples

library(pipenostics)

# Minimum two nodes should be in district heating network graph:
tracefw(verbose = FALSE)
#>   node tracing backward aggregation loss     flux        Q temperature
#> 1    1  sensor    FALSE    identity   NA       NA       NA    70.00000
#> 2    2       1    FALSE    identity 78.4 290.2324 136314.4    69.71603
#>    pressure flow_rate job
#> 1 0.5883990        20   0
#> 2 0.5704644        20   1

# Consider isomorphic representation of District Heating Network graph:
DHN <- m325nxdata

# * remove irrelevant parameters from the test bench:
DHN[c("a", "year", "insulation", "laying", "beta", "exp5k")] <- NULL
DHN[c("temperature", "pressure", "flow_rate")] <- NA_real_

# * avoid using numeric identifiers for nodes:
DHN$sender   <- sprintf("N%02i", DHN$sender)
DHN$acceptor <- sprintf("N%02i", DHN$acceptor)

# * provide current regime parameters for root node:
root_node <- 12
DHN[root_node, "temperature"] <-  70.4942576978  # [°C]
DHN[root_node, "pressure"]    <-   0.6135602014  # [MPa]
DHN[root_node, "flow_rate"]   <- 274.0           # [ton/h]
rm(root_node)

# * provide actual values of specific heat loss power, [kcal/m/h], for each
# segment N01 - N26. Since N12 is a root node, the specific heat loss
# power for this acceptor is set to 0 (or may be any other numeric value).
actual_loss <- c(
  96.8,  96.8,  71.2, 116.7, 71.3,  96.8, 78.5, 116.7, 28.6, 24.5,
 116.7,   0.0, 153.2,  96.8, 96.8, 116.7, 24.5, 116.7, 28.6, 96.8,
  78.5, 116.7,  71.3,  96.8, 96.8,  71.1
)

# Trace the test bench forward for the first time:
do.call(
  "tracefw",
  c(as.list(DHN), list(loss = actual_loss), verbose = FALSE, elev_tol = .5)
)
#>    node tracing backward aggregation  loss     flux         Q temperature
#> 1   N12  sensor    FALSE    identity    NA       NA        NA    70.49426
#> 2   N13     N12    FALSE    identity 153.2 189.6782 363201.66    70.43903
#> 3   N11     N13    FALSE    identity 116.7 216.0084  84024.00    70.40629
#> 4   N08     N11    FALSE    identity 116.7 216.0084  84024.00    70.37151
#> 5   N04     N08    FALSE    identity 116.7 216.0084  39981.42    70.34565
#> 6   N01     N04    FALSE    identity  96.8 238.8988  92567.90    70.22589
#> 11  N02     N04    FALSE    identity  96.8 238.8988  92567.90    70.22589
#> 41  N06     N08    FALSE    identity  96.8 238.8988 140514.11    70.20993
#> 51  N05     N06    FALSE    identity  71.3 329.9358  61890.68    69.95637
#> 61  N03     N05    FALSE    identity  71.2 329.4730 132045.81    69.41539
#> 52  N07     N06    FALSE    identity  78.5 290.6026 136488.26    69.85206
#> 53  N09     N06    FALSE    identity  28.6 132.3445  20646.23    70.12534
#> 31  N10     N11    FALSE    identity  24.5 181.3953  12873.08    70.32103
#> 21  N14     N13    FALSE    identity  96.8 238.8988 158721.02    70.32909
#> 32  N15     N14    FALSE    identity  96.8 238.8988 184787.33    70.20109
#> 22  N16     N13    FALSE    identity 116.7 216.0084  84024.00    70.40629
#> 33  N17     N16    FALSE    identity  24.5 181.3953  12873.08    70.32103
#> 34  N18     N16    FALSE    identity 116.7 216.0084  86292.65    70.37057
#> 42  N20     N18    FALSE    identity  96.8 238.8988 155101.48    70.19221
#> 54  N19     N20    FALSE    identity  28.6 132.3445  35673.58    70.04606
#> 55  N21     N20    FALSE    identity  78.5 290.6026 136488.26    69.83434
#> 43  N22     N18    FALSE    identity 116.7 216.0084  86292.65    70.31475
#> 56  N24     N22    FALSE    identity  96.8 238.8988  59137.06    70.23825
#> 57  N25     N22    FALSE    identity  96.8 238.8988  59137.06    70.23825
#> 58  N23     N20    FALSE    identity  71.3 329.9358  88934.49    69.82786
#> 62  N26     N23    FALSE    identity  71.1 329.0103 131860.35    69.28763
#>     pressure  flow_rate job
#> 1  0.6135602 274.000000   0
#> 2  0.5979750 274.000000   1
#> 3  0.5939089 106.926829   1
#> 4  0.5903066 100.637016   1
#> 5  0.5896032  64.407690   1
#> 6  0.5873626  32.203845   1
#> 11 0.5873626  32.203845   2
#> 41 0.5831283  36.229326   3
#> 51 0.5745519  10.169635   3
#> 61 0.5603297  10.169635   3
#> 52 0.5694825  15.890055   4
#> 53 0.5775906  10.169635   5
#> 31 0.5645381   6.289813   6
#> 21 0.5846161  60.146341   7
#> 32 0.5690643  60.146341   7
#> 22 0.5939089 106.926829   8
#> 33 0.5645381   6.289813   8
#> 34 0.5902093 100.637016   9
#> 42 0.5854615  36.229326   9
#> 54 0.5758935  10.169635   9
#> 55 0.5766115  15.890055  10
#> 43 0.5886914  64.407690  11
#> 56 0.5872599  32.203845  11
#> 57 0.5872599  32.203845  12
#> 58 0.5710985  10.169635  13
#> 62 0.5568771  10.169635  13