Q: How do you make a balance sheet of the evaporator in a brine chiller?
Evaporator balance sheet is made by comparing the heat removed from brine and heat absorbed by refrigerant, ensuring the system operates efficiently and within acceptable energy balance limits.
1. Objective:
To prepare a heat balance sheet that shows the energy entering and leaving the evaporator to evaluate its efficiency and performance.
2. Steps to Prepare Balance Sheet:
(a) Collect Input Data:
Inlet and outlet brine temperatures (T₁ & T₂).
Brine flow rate (ṁ) in kg/s.
Specific heat (Cp) of brine solution.
Refrigerant pressures and enthalpies (h₁ & h₄) from P–h diagram or system data.
(b) Calculate Heat Extracted from Brine:
(c) Calculate Heat Absorbed by Refrigerant:
(d) Compare Heat Balance:
3. Interpretation:
If large deviation → possible heat losses, improper insulation, or measurement errors.
Used to analyze performance, detect inefficiencies, and verify evaporator design capacity.