pipenostics (version 0.1.7)

m325tracebw: Minenergo-325. Trace backwards thermal-hydraulic regime for district heating network

Description

Trace values of thermal-hydraulic regime (temperature, pressure, consumption) in the bunched pipeline against the flow direction using norms of heat flux values prescribed by Minenergo Order 325.

Usage

m325tracebw(
  sender = 6,
  acceptor = 7,
  temperature = 70,
  pressure = pipenostics::mpa_kgf(6),
  consumption = 20,
  d = 100,
  len = 72.446,
  year = 1986,
  insulation = 0,
  laying = "tunnel",
  beta = FALSE,
  exp5k = TRUE,
  roughness = 0.001,
  inlet = 0.5,
  outlet = 1,
  method = "romeo",
  opinion = "median",
  verbose = TRUE,
  csv = FALSE,
  file = "m325tracebw.csv"
)

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

snapshot of thermal-hydraulic regime state: temperature of heat carrier (water) sensor-measured on the terminal acceptor node, [<U+00B0>C]. Use NA_float_s for nodes without temperature sensor. Type: assert_double.

pressure

snapshot of thermal-hydraulic regime state: sensor-measured absolute pressure of heat carrier (water) inside the pipe (i.e. acceptor's incoming edge), [MPa]. Type: assert_double.

consumption

snapshot of thermal-hydraulic regime state: sensor-measured amount of heat carrier (water) on terminal node that is transferred by pipe (i.e. acceptor's incoming edge) during a period, [ton/hour]. Type: assert_double. Use NA_float_s for nodes without consumption sensor.

d

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

len

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

year

year when the pipe (i.e. acceptor's incoming edge) is put in operation after laying or total overhaul. Type: assert_integerish.

insulation

identifier of insulation that covers the exterior of pipe (i.e. acceptor's incoming edge):

0

no insulation

1

foamed polyurethane or analogue

2

polymer concrete

Type: assert_subset.

laying

type of pipe laying depicting the position of pipe in space. Only five types of pipe laying are considered:

• air,

• channel,

• room,

• tunnel,

• underground.

Type: assert_subset.

beta

logical indicator: should they consider additional heat losses of fittings located on this pipe (i.e. acceptor's incoming edge)? Type: assert_logical.

exp5k

logical indicator for regime of pipe (i.e. acceptor's incoming edge): if TRUE pipe is operated more that 5000 hours per year. Type: assert_logical.

roughness

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

inlet

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

outlet

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

method

method of determining Darcy friction factor:

• romeo

• vatankhan

• buzelli

Type: assert_choice. For more details see dropp.

opinion

method for aggregating values of regime parameters on each node for the next tracing step:

mean

values of parameter are averaged before the next tracing step

median

median of parameter values are used for the next tracing step

Type: assert_choice.

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.

Value

data.frame containing results of tracing in long format (narrow format) mostly like it returned by function m325tracefw:

node

identifier of the node for which regime parameters is calculated. Values in this vector are identical to those in argument acceptor. Type: assert_character.

trace

concatenated 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

identifier of tracing direction. It constantly equals to TRUE. Type: assert_logical.

aggregation

aggregation method associated with values of calculated temperature or pressure in data.frame's row for the node:

identity

values (opinions) of temperature or pressure as they are (no aggregation).

span

span of values (opinions) of temperature or pressure for the node

median

median of values (opinions) of temperature or pressure for the node

mean

avaraged values (opinions) temperature or pressure for the node

Type: assert_character.

temperature

snapshot of thermal-hydraulic regime state: traced temperature of heat carrier (water) that is associated with the node, [<U+00B0>C] Type: assert_double.

pressure

snapshot of thermal-hydraulic regime state: traced pressure of heat carrier (water) that is associated with the node, [MPa] Type: assert_double.

consumption

snapshot of thermal-hydraulic regime state: traced pressure of heat carrier (water) that is associated with the node, [ton/hour] Type: assert_double.

job

value of trace step counter. Type: assert_integer.

Details

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 the topology of district heating network much similar to m325testbench:

Tracing starts from sensor-equipped nodes and goes backwards, i.e against the flow direction.

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 m325testbench.

Before tracing starts for the next node, previously calculated values of temperature or pressure at the node are aggregated by either averaging or by median. The latter seems more robust for avoiding strong influence of possible outliers which may come from actual heating transfer anomalies, erroneous sensor readings or wrong pipeline specifications.

Aggregation for values of consumption at the node is always sum.

See Also

Other Regime tracing: m325tracefw(), m325traceline()

Examples

# NOT RUN {
# It is possible to run without specification of argument values:
m325tracebw()

# Get isomorphic representation of district heating network graph:
nx <- pipenostics::m325testbench
nx$d <- 1e3*nx$d  # convert [m] to [mm]

# When tracing large network graphs put screen log to file
output <- do.call("m325tracebw", c(as.list(nx), verbose = TRUE))

# Distinct options for opinion aggregation lead to distinct traced
# temperature and pressure:
output <- list(
  mean   = do.call("m325tracebw",
                   c(as.list(nx), verbose = FALSE, opinion = "mean")),
  median = do.call("m325tracebw",
                   c(as.list(nx), verbose = FALSE, opinion = "median"))
)

stopifnot(
  round(
    subset(
      output$mean,
      node == 13 & aggregation == "median",
      c("temperature", "pressure", "consumption")
    ) - subset(
      output$median,
      node == 13 & aggregation == "median",
      c("temperature", "pressure", "consumption")
    ),
    5
    # difference between aggregation options
  ) == c(dt = 0.03732, dp = 0.00139, dg = 0)
)
# }