function calculateHeatRate() {
// Get input values
var powerGenMW = parseFloat(document.getElementById("powerGeneration").value);
var auxPercent = parseFloat(document.getElementById("auxConsumption").value);
var coalFlowTPH = parseFloat(document.getElementById("coalFlow").value);
var gcv = parseFloat(document.getElementById("gcv").value);
// Validation
if (isNaN(powerGenMW) || isNaN(auxPercent) || isNaN(coalFlowTPH) || isNaN(gcv) || powerGenMW <= 0) {
alert("Please enter valid positive numbers for all fields.");
return;
}
// 1. Calculate Heat Input in kcal/hr
// Convert Tonnes/hr to kg/hr by multiplying by 1000
var coalFlowKgHr = coalFlowTPH * 1000;
var heatInputKcalHr = coalFlowKgHr * gcv;
// 2. Calculate Gross Power in kW (Heat Rate is typically kcal/kWh)
var grossPowerKW = powerGenMW * 1000;
// 3. Calculate Net Power in kW
// Net = Gross – Aux
var auxPowerKW = grossPowerKW * (auxPercent / 100);
var netPowerKW = grossPowerKW – auxPowerKW;
// 4. Calculate Gross Heat Rate (kcal/kWh)
var grossHeatRate = heatInputKcalHr / grossPowerKW;
// 5. Calculate Net Heat Rate (kcal/kWh)
var netHeatRate = heatInputKcalHr / netPowerKW;
// 6. Calculate Thermal Efficiency (%)
// 1 kWh = 860 kcal
// Efficiency = 860 / Net Heat Rate * 100
var efficiency = (860 / netHeatRate) * 100;
// Display Results
document.getElementById("resHeatInput").innerHTML = (heatInputKcalHr / 1000000).toFixed(2) + " Gcal/hr";
document.getElementById("resGrossHR").innerHTML = grossHeatRate.toFixed(2) + " kcal/kWh";
document.getElementById("resNetHR").innerHTML = netHeatRate.toFixed(2) + " kcal/kWh";
document.getElementById("resEfficiency").innerHTML = efficiency.toFixed(2) + "%";
// Show result div
document.getElementById("resultSection").style.display = "block";
}
How to Calculate Heat Rate of a Thermal Power Plant
In the power generation industry, the term "Heat Rate" is effectively the heartbeat of a thermal power plant. It acts as the primary indicator of the plant's thermal efficiency. While often mistaken by laypeople as a "heart rate," engineers understand this metric as the amount of heat energy required to generate a specific unit of electricity.
A lower Heat Rate indicates a more efficient power plant, as it consumes less fuel to produce the same amount of electricity. Conversely, a higher Heat Rate signifies inefficiencies and higher fuel costs.
Definition: Heat Rate is the heat energy input (in kcal, Btu, or kJ) required to generate one kilowatt-hour (kWh) of electrical energy.
The Core Formulas
To calculate the performance of your plant, you need to understand the difference between Gross Heat Rate and Net Heat Rate.
1. Gross Heat Rate (GHR)
This measures the efficiency of the boiler and turbine relative to the total electricity generated, ignoring the power consumed by the plant itself (auxiliary power).