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]. Relevant formulas and values are documented below.

Heat Loss

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\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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Reference temperature: \(\qty{60}{ \degreeFahrenheit}\)

Gas Type	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

Modules
	Atmosphere Heat Loss Formula
	Atmosphere Specific Heat Values

Files
file	atmosphere_heat_loss.h

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

Classes
struct	atmosphere_heat_loss::GasType
	Represents a gas type and its associated specific heat at a reference temperature of \(\qty{60}{\degreeFahrenheit}\). More...

Functions
const std::vector< GasType > &	atmosphere_heat_loss::gasTypes ()
	Returns the predefined specific heat values for common atmospheric gases at a reference temperature of \(\qty{60}{\degreeFahrenheit}\).
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.

Variables
const std::array< GasType, 6 >	atmosphere_heat_loss::kGasTypes
	A collection of specific heat values for common atmospheric gases at a reference temperature of \(\qty{60}{\degreeFahrenheit}\).

Function Documentation

gasTypes()

const std::vector< GasType > & atmosphere_heat_loss::gasTypes ( )

inline

Returns

A vector of GasType structs containing gas descriptions and their associated specific heat values.

See also

Atmosphere Specific Heat Values

Definition at line 55 of file atmosphere_heat_loss.h.

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

Variable Documentation

kGasTypes

const std::array<GasType, 6> atmosphere_heat_loss::kGasTypes

inline

Initial value:

{{
    {"Nitrogen", 0.0185},
    {"Hydrogen", 0.0182},
    {"Exothermic Gas", 0.0185},
    {"Endothermic Gas", 0.0185},
    {"Air", 0.0184},
    {"Water Vapor", 0.0212},
}}

See also

Atmosphere Specific Heat Values

Definition at line 39 of file atmosphere_heat_loss.h.