To improve the cooling time required to chill the milk, 1) 2500 liters milk is chilled from 35°C to 4°C in less than 3 hours, and 2) 5000 liters milk is chilled from 10°C to 4°C in less than 1.2 hours.
The basic idea of doing these trial simulations are, when we run the new design modifications in terms of tank side modifications, the heat transfer coefficients at refrigerant side would not change with these tank side modifications, so for design modifications refrigerant side heat transfer coefficients and refrigerant temperatures have been kept constant. CFD simulations are carried out for the existing design with current 25 rpm single agitator case, after series of analyses, the results are matched with the experimental results and those matching results, heat transfer coefficients and evaporator temperatures have been used for the same existing design to cross check the analysis results. Also carried out the new calculations with the same heat transfer coefficients & evaporator plate temperature boundary conditions.
From the above simulations results for the existing & modified milk cooling tank for the 1st case & 2nd case we can conclude,
1. In 1st case, overall 6 minutes of (comparing base case & modified case) saving in chilling the water from 35 0C to 4 0C.
2. In 2nd case, overall 1 minute 10 seconds of saving in chilling the water from 10 0C to 4 0C.