# R/m278hlcha.R In pipenostics: Diagnostics, Reliability and Predictive Maintenance of Pipeline Systems

#### Documented in m278hlcha

#' @title
#'  Minenergo-278. Heat losses of pipeline segment in channel
#'
#'
#' @family Minenergo
#'
#' @description
#'  Calculate values of heat flux emitted by pipeline segment mounted in channel
#'  as a function of construction, operation, and technical condition
#'  specifications according to
#'  Appendix 5.1 of \href{http://www.complexdoc.ru/ntdtext/547103/}{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.
#'
#' @param t1
#'   temperature of heat carrier (water) inside the supplying pipe, [\emph{°C}].
#' @param t2
#'   temperature of heat carrier (water) inside the returning pipe, [\emph{°C}].
#' @param t0
#'   temperature of environment, [\emph{°C}]. In case of channel laying this is
#'   the temperature of subsoil. Type: \code{\link{assert_double}}.
#' @param insd1
#'   thickness of the insulator which covers the supplying pipe, [\emph{m}].
#' @param insd2
#'   thickness of the insulator which covers the returning pipe, [\emph{m}].
#' @param d1
#'   external diameter of supplying pipe, [\emph{m}]. Type: \code{\link{assert_double}}.
#' @param d2
#'   external diameter of returning pipe, [\emph{m}]. Type: \code{\link{assert_double}}.
#' @param lambda1
#'   thermal conductivity of insulator which covers the supplying pipe
#' @param lambda2
#'   thermal conductivity of insulator which covers the returning pipe
#' @param k1
#'   technical condition factor for insulator of supplying pipe, [].
#' @param k2
#'   technical condition factor for insulator of returning pipe, [].
#' @param lambda0
#'   thermal conductivity of environment, [\emph{W/m/°C}]. In case of channel
#'   laying this is the thermal conductivity of subsoil. Type: \code{\link{assert_double}}.
#' @param z
#'   channel laying depth, [\emph{m}]. Type: \code{\link{assert_double}}.
#' @param b
#'   channel width, [\emph{m}]. Type: \code{\link{assert_double}}.
#' @param h
#'   channel height, [\emph{m}]. Type: \code{\link{assert_double}}.
#' @param len
#'  length of pipeline segment, [\emph{m}]. Type: \code{\link{assert_double}}.
#' @param duration
#'  duration of heat flux emittance, [\emph{hour}]. Type: \code{\link{assert_double}}.
#'
#' @return
#'  Heat flux emitted by pipeline segment during \code{duration}, [\emph{kcal}].
#'  If \code{len} of pipeline segment is 1 \emph{m} and \code{duration} of
#'  heat flux emittance is set to 1 \emph{hour} then the return value is equal
#'  to that in [\emph{kcal/m/h}] units and so comparable with values of
#'  heat flux listed in
#'  \href{http://docs.cntd.ru/document/902148459}{Minenergo Order 325}.
#'
#' @details
#'   \code{k1} and \code{k2} factor values equal to one mean the best technical
#'   condition of insulation of appropriate pipes, whereas for poor technical
#'   state factor values tends to five or more.
#'
#'   Nevertheless, when \code{k1} and \code{k2} both equal to one the calculated
#'   heat flux [\emph{kcal/m/h}] is sometimes higher than that listed in
#'   \href{http://docs.cntd.ru/document/902148459}{Minenergo Order 325}.
#'   One should consider that situation when choosing method for heat loss
#'   calculations.
#' @export
#'
#' @examples
#'  m278hlcha()
#'  #
#'
#'  ## Naive way to find out technical state (factors k1 and k2) for pipe
#'  ## segments constructed in 1980:
#'    optim(
#'      par = c(1.5, 1.5),
#'      fn = function(x) {
#'      # functional to optimize
#'        abs(
#'            m278hlcha(k1 = x, k2 = x) -
#'            m325nhl(year = 1980, laying = "channel", d = 250, temperature = 110)
#'        )
#'      },
#'      method = "L-BFGS-B",
#'      lower = 1.01, upper = 4.4
#'    )\$par
#'    #  4.285442 4.323628
#'
m278hlcha <-
function(t1 = 110,
t2 = 60,
t0 = 5,
insd1 = 0.1,
insd2 = insd1,
d1 = .25,
d2 = d1,
lambda1 = 0.09,
lambda2 = 0.07,
k1 = 1,
k2 = k1,
lambda0 = 1.74,
z = 2,
b = 0.5,
h = 0.5,
len = 1,
duration = 1) {
checkmate::assert_double(
t1,
lower = 0,
upper = 450,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(
t2,
lower = 0,
upper = 450,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(
t0,
lower = -15,
upper = 30,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(
insd1,
lower = 0,
upper = .5,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(
insd2,
lower = 0,
upper = .5,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(
d1,
lower = .2,
upper = 1.5,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(
d2,
lower = .2,
upper = 1.5,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(
lambda1,
lower = 1e-3,
upper = 1,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(
lambda2,
lower = 1e-3,
upper = 1,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(
k1,
lower = 1,
upper = 4.5,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(
k2,
lower = 1,
upper = 4.5,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(
lambda0,
lower = 1e-3,
upper = 3,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(
z,
lower = .1,
upper = 10,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(
b,
lower = min(d1, d2),
upper = 10,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(
h,
lower = min(d1, d2),
upper = 10,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)
checkmate::assert_double(len,
lower = 0,
finite = TRUE,
any.missing = FALSE,
min.len = 1)
checkmate::assert_double(duration,
lower = 0,
finite = TRUE,
any.missing = FALSE,
min.len = 1
)

R0 <- log(3.5 * z / h * (h / b) ^ .25) / lambda0 / (5.7 + .5 * b /
h)
d <- 2 * b * h / (b + h)
R_chan_air <- 1 / (8 * pi * d)
R1_air <- 1 / (8 * pi * (d1 + 2 * insd1))
R2_air <- 1 / (8 * pi * (d2 + 2 * insd2))
R1_ins <- log(1 + 2 * insd1 / d1) / (2 * pi * k1 * lambda1)
R2_ins <- log(1 + 2 * insd2 / d2) / (2 * pi * k2 * lambda2)
t_chan <-
(t1 / (R1_ins + R1_air) + t2 / (R2_ins + R2_air) + t0 / (R_chan_air + R0)) /
(1 / (R1_ins + R1_air) + 1 / (R2_ins + R2_air) + 1 / (R_chan_air + R0))
q <- (t_chan - t0) / (R_chan_air + R0)

q * len * duration
}


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