# m325dropt: Minenergo-325. Temperature drop in pipe due heat losses In pipenostics: Diagnostics, Reliability and Predictive Maintenance of Pipeline Systems

## Description

Calculate temperature drop in steel pipe of district heating system (where water is a heat carrier) that is a result of heat losses through pipe wall and insulation using Minenergo Order 325 as a basis for values of heating flux.

Since Minenergo Order 325 is used as the basis for values of heating flux the calculated temperature drop may be considered as a normative temperature drop. If the actual (somehow measured) temperature drop is more than this normative temperature drop they may consider such difference to be due to extra-normative heat losses. The presence of the latter requires appropriate maintenance activities.

## Usage

 ``` 1 2 3 4 5 6 7 8 9 10 11 12``` ```m325dropt( temperature = 130, pressure = mpa_kgf(6), consumption = 250, d = 700, len = 1, year = 1986, insulation = 0, laying = "underground", beta = FALSE, exp5k = TRUE ) ```

## Arguments

 `temperature` temperature of heat carrier (water) inside the pipe measured at the entrance of pipe, [°C]. Type: `assert_double`. `pressure` absolute pressure of heat carrier (water) inside the pipe, [MPa]. Type: `assert_double`. `consumption` amount of heat carrier (water) that is transferred by pipe during a period, [ton/hour]. Type: `assert_double`. `d` internal diameter of pipe, [mm]. Type: `assert_double`. `len` length of pipe, [m]. Type: `assert_double`. `year` year when the pipe is put in operation after laying or total overhaul. Type: `assert_integerish`. `insulation` insulation that covers the exterior of pipe: `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: `air`, `channel`, `room`, `tunnel`, `underground`. Type: `assert_subset`. `beta` should they consider additional heat losses of fittings? Type: `assert_logical`. `exp5k` pipe regime flag: is pipe operated more that 5000 hours per year? Type: `assert_logical`.

## Details

The function is a simple wrapper for call of `dropt` with parameter `flux` calculated by `m325nhl`.

## Value

normative temperature drop at the outlet of pipe, [°C]. Type: `assert_double`.

`dropt` for calculating temperature drop in pipe using actual heat flux values
Other Minenergo: `m278hlair()`, `m278hlcha()`, `m278hlund()`, `m278insdata`, `m278inshcm()`, `m278soildata`, `m325beta()`, `m325nhldata`, `m325nhl()`, `m325testbench`
 ```1 2 3 4 5 6``` ``` stopifnot( round( m325dropt( temperature = 130, year = 1968, laying = "channel", d = 700, l = 1000 ), 2) == 1.37 ) ```