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Calcimator

Energy Balance Calculator

Calculate steady-state energy balance for a process stream. Includes sensible heat (Q = mCpΔT), latent heat of phase change, and reaction heat contributions.

Inputs

Results

Total duty (kW)

319.76

Sensible heat (kW)319.76
Latent heat (kW)0
Reaction heat (kW)0
Total duty (BTU/hr)1,091,079
Total duty (GJ/hr)1.15
Steam estimate (kg/hr)571.3
Cooling water estimate (kg/hr)0
Total Duty MW0.32
How to Use This Calculator
  1. Enter Mass flow rate (kg/hr), Specific heat Cp (kJ/kg·K), and Inlet temperature (°C).
  2. Set Outlet temperature (°C), Latent heat (kJ/kg), and Phase change fraction (0–1).
  3. Adjust Heat of reaction (kJ/kg) as needed.
  4. Review the Total duty (kW) result.
  5. Use Sensible heat (kW) and Latent heat (kW) to inform your decision.

How the result changes with Outlet temperature (°C)

Outlet temperature (°C)Total duty (kW)
-46-412.79
5232,895.32
1,2046,854.57
1,77310,162.68

What each input means

Mass flow rate (kg/hr)
Total mass flow rate through the process unit.
Specific heat Cp (kJ/kg·K)
Specific heat capacity. Water = 4.186, oil ≈ 2.0, air ≈ 1.005 kJ/(kg·K).
Inlet temperature (°C)
Temperature of the stream entering the process unit.
Outlet temperature (°C)
Temperature of the stream leaving the process unit.
Latent heat (kJ/kg)
Heat of vaporization/condensation (water ≈ 2257 kJ/kg). Set 0 if no phase change.
Phase change fraction (0–1)
Fraction of the stream that undergoes phase change (0 = none, 1 = complete).
Heat of reaction (kJ/kg)
Exothermic = negative, endothermic = positive. Set 0 if no reaction.

What each result means

Total duty (kW)
Net heat duty. Positive = heating needed, negative = cooling needed.
Sensible heat (kW)
Heat required to change temperature: mCpΔT.
Latent heat (kW)
Heat for phase change.
Reaction heat (kW)
Heat generated or consumed by chemical reaction.
Total duty (BTU/hr)
Duty in imperial units.
Total duty (GJ/hr)
Duty in gigajoules per hour.
Steam estimate (kg/hr)
Estimated 10 barg saturated steam consumption (for heating duties only).
Cooling water estimate (kg/hr)
Estimated cooling water flow at 10°C rise (for cooling duties only).

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Mass flow rate (kg/hr) = 5000, Specific heat Cp (kJ/kg·K) = 4.186, Inlet temperature (°C) = 25, Outlet temperature (°C) = 80 = 7 input(s) provided
  2. Calculate Total duty
    Total duty = sensibleKW + latentKW + reactionKW
    319.76 = 319.76
  3. Calculate Sensible heat
    Sensible heat = massFlowKgS * cpKJ * deltaT
    319.76 = 319.76
  4. Calculate Latent heat
    Latent heat = massFlowKgS * latentHeat * phaseChangeFraction
    0 = 0

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