Atmosphere Heat Loss Calculator

Detailed Description

This calculator is used to estimate heat losses of process heating equipment due to the introduction of atmospheric gases (e.g., nitrogen, hydrogen, etc.). These gases absorb heat from the equipment and carry it away when they exit the system. The calculator computes the total heat loss based on the flow rate, specific heat of the gas, inlet and outlet temperatures, and a correction factor [3].

The calculation follows a top-down approach:

1. Total Heat Loss - Calculate the heat absorbed by atmospheric gases as they pass through the system

Relevant formulas and values are documented below.

Total Heat Loss

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Total heat loss due to atmospheric gases.

The heat loss is calculated by multiplying the volumetric flow rate, specific heat capacity, temperature rise of the gas, and a correction factor. This represents the sensible heat absorbed by the atmospheric gas as it passes through the heating equipment.

\begin{equation}\label{eq:atmosphere-heat-loss} Q = \dot{v} \cdot c_p \cdot (T_\text{out} - T_\text{in}) \cdot f_\text{corr}\end{equation}

Symbols

\(Q\)	Heat loss \([\unit{ \btu\per\hour}]\)
\(\dot{v}\)	Flow rate of gas \([\unit{ \standardCubicFeet\per\hour}]\)
\(c_p\)	Specific heat of gas \([\unit{ \btu\per\standardCubicFeet\degreeFahrenheit}]\)
\(T_\text{out}\)	Outlet temperature of gas \([\unit{ \degreeFahrenheit}]\)
\(T_\text{in}\)	Inlet temperature of gas \([\unit{ \degreeFahrenheit}]\)
\(f_\text{corr}\)	Correction factor \([\unit{ \unitless}]\)

Specific Heat Values

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The following table lists the default gas types and their specific heat values:

Gas Description	Specific Heat \([\unit{\btu\per\standardCubicFeet\degreeFahrenheit}]\)
Nitrogen	0.0185
Hydrogen	0.0182
Exothermic Gas	0.0185
Endothermic Gas	0.0185
Air	0.0184
Water Vapor	0.0212

Note

Values are at a reference temperature of \(\qty{60}{\degreeFahrenheit}\) and may vary with pressure and temperature.

See also

Atmosphere Heat Loss Calculator see gas_type_data

Modules
	Atmosphere Heat Loss Formula
	Total heat loss due to atmospheric gases.

Files
file	atmosphere_heat_loss.h

Namespaces
namespace	atmosphere_heat_loss
	Calculates heat losses from escaping atmospheric gases in process heating equipment.

Functions
double	atmosphere_heat_loss::totalHeatLoss (double flow_rate, double specific_heat, double inlet_temperature, double outlet_temperature, double correction_factor)
	Calculates the total heat loss from escaping atmospheric gas.

Function Documentation

totalHeatLoss()

double atmosphere_heat_loss::totalHeatLoss	(	double	flow_rate,
		double	specific_heat,
		double	inlet_temperature,
		double	outlet_temperature,
		double	correction_factor
	)

Parameters

[in]	flow_rate	Flow rate of gas \([\unit{\standardCubicFeet\per\hour}]\)
[in]	specific_heat	Specific heat of gas \([\unit{\btu\per\standardCubicFeet\degreeFahrenheit}]\)
[in]	inlet_temperature	Inlet temperature of gas \([\unit{\degreeFahrenheit}]\)
[in]	outlet_temperature	Outlet temperature of gas \([\unit{\degreeFahrenheit}]\)
[in]	correction_factor	Correction factor \([\unit{\unitless}]\)

Returns

Total heat loss \([\unit{\btu\per\hour}]\)

See also

• Atmosphere Heat Loss Formula
• atmosphere_specific_heat_values