Energy Equivalency Calculator

Detailed Description

This calculator estimates the equivalent heat input required when switching between fuel-fired and electrically heated furnaces. The calculation uses process heat input and equipment efficiencies. Methods are based on standard industrial practice for process heating systems.

The calculation follows:

1. Electrical Equivalent Heat Input - Calculate the electrical heat input required to replace a fuel-fired furnace
2. Fuel-Fired Equivalent Heat Input - Calculate the fuel-fired heat input required to replace an electrically heated furnace

Relevant formulas and symbol definitions are documented below.

Electrical Equivalent Heat Input

---

Calculates the electrical heat input required to replace a fuel-fired furnace.

The equivalent electrical heat input is calculated as:

\begin{equation}\label{eq:energy-equivalency-electrical} P_{elec} = \frac{P_{fuel} \cdot \eta_{fuel}}{\eta_{elec}}\end{equation}

Symbols

\(P_{elec}\)	Equivalent electrical heat input \([\unit{ \kilo\watt}]\)
\(P_{fuel}\)	Fuel-fired heat input \([\unit{ \mega\btu\per\hour}]\)
\(\eta_{fuel}\)	Fuel-fired furnace efficiency \([\unit{ \percent}]\)
\(\eta_{elec}\)	Electrically heated furnace efficiency \([\unit{ \percent}]\)

Note

The result is converted from MMBtu/hr to kW using the factor 1 MMBtu/hr = 293.07107 kW.

Fuel-Fired Equivalent Heat Input

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Calculates the fuel-fired heat input required to replace an electrically heated furnace.

The equivalent fuel-fired heat input is calculated as:

\begin{equation}\label{eq:energy-equivalency-fuel-fired} P_{fuel} = \frac{P_{elec} \cdot \eta_{elec}}{\eta_{fuel}}\end{equation}

Symbols

\(P_{fuel}\)	Equivalent fuel-fired heat input \([\unit{ \mega\btu\per\hour}]\)
\(P_{elec}\)	Electrical heat input \([\unit{ \kilo\watt}]\)
\(\eta_{elec}\)	Electrically heated furnace efficiency \([\unit{ \percent}]\)
\(\eta_{fuel}\)	Fuel-fired furnace efficiency \([\unit{ \percent}]\)

Note

The result is converted from kW to MMBtu/hr using the factor 1 kW = 0.003412142 MMBtu/hr.

Modules
	Electrical Equivalent Heat Input Formula
	Calculates the electrical heat input required to replace a fuel-fired furnace.
	Fuel-Fired Equivalent Heat Input Formula
	Calculates the fuel-fired heat input required to replace an electrically heated furnace.

Files
file	energy_equivalency.h
	Energy equivalency calculations for process heating systems.

Namespaces
namespace	energy_equivalency
	Energy equivalency calculations for process heating systems.

Functions
double	energy_equivalency::calculateElectricalEquivalentHeatInput (double fuel_fired_heat_input, double fuel_fired_efficiency, double electrically_heated_efficiency)
	Calculates the equivalent electrical heat input required to replace a fuel-fired furnace.
double	energy_equivalency::calculateFuelFiredEquivalentHeatInput (double electrical_heat_input, double electrically_heated_efficiency, double fuel_fired_efficiency)
	Calculates the equivalent fuel-fired heat input required to replace an electrically heated furnace.

Function Documentation

calculateElectricalEquivalentHeatInput()

double energy_equivalency::calculateElectricalEquivalentHeatInput	(	double	fuel_fired_heat_input,
		double	fuel_fired_efficiency,
		double	electrically_heated_efficiency
	)

Uses the fuel-fired heat input and efficiencies to determine the equivalent electrical input.

Parameters

[in]	fuel_fired_heat_input	Fuel-fired heat input \([\unit{MMBtu/hr}]\)
[in]	fuel_fired_efficiency	Fuel-fired furnace efficiency \([\unit{\percent}]\)
[in]	electrically_heated_efficiency	Electrically heated furnace efficiency \([\unit{\percent}]\)

Returns

Equivalent electrical heat input \([\unit{kW}]\)

calculateFuelFiredEquivalentHeatInput()

double energy_equivalency::calculateFuelFiredEquivalentHeatInput	(	double	electrical_heat_input,
		double	electrically_heated_efficiency,
		double	fuel_fired_efficiency
	)

Uses the electrical heat input and efficiencies to determine the equivalent fuel-fired input.

Parameters

[in]	electrical_heat_input	Electrical heat input \([\unit{kW}]\)
[in]	electrically_heated_efficiency	Electrically heated furnace efficiency \([\unit{\percent}]\)
[in]	fuel_fired_efficiency	Fuel-fired furnace efficiency \([\unit{\percent}]\)

Returns

Equivalent fuel-fired heat input \([\unit{MMBtu/hr}]\)