1. What is Heat Flow Rate?

Definition: Heat flow rate (Q) is the amount of thermal energy transferred per unit time, measured in watts (W).

Purpose: This calculation is essential in thermodynamics, HVAC systems, heat exchanger design, and energy efficiency analysis.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Heat flow rate (watts)
• \( m \) — Mass flow rate (kg/s)
• \( c_p \) — Specific heat capacity (J/kg·K)
• \( \Delta T \) — Temperature difference (K)

Explanation: The formula calculates the thermal energy transfer based on how much mass is flowing, its heat capacity, and the temperature change.

3. Importance of Heat Flow Rate Calculation

Details: Accurate heat flow calculations are crucial for designing efficient thermal systems, sizing equipment, and energy conservation.

4. Using the Calculator

Tips: Enter the mass flow rate in kg/s, specific heat capacity (default 4.186 J/kg·K for water), and temperature difference in Kelvin. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is specific heat capacity?
A: The amount of heat required to raise 1 kg of a substance by 1 K (water = 4.186 J/kg·K, air ≈ 1.005 J/kg·K).

Q2: Can I use °C instead of K for ΔT?
A: Yes, because 1°C change equals 1K change in magnitude (only the zero points differ).

Q3: What's a typical mass flow rate for water?
A: Domestic water systems might have 0.05-0.2 kg/s, while industrial systems can have much higher flows.

Q4: How do I find mass flow rate?
A: Measure volumetric flow (m³/s) and multiply by fluid density (kg/m³).

Q5: What affects specific heat capacity?
A: Material type, temperature, and sometimes pressure (though for most solids/liquids, pressure effect is minimal).