Fill the jacket with cold glycol, hold for a period of time to transfer heat and then replace it with fresh coolant. Good money is required to cool glycol so why only get a partial return with a constant flow?

If you were to introduce pulse cooling tomorrow you would be on the way to halving your refrigeration load for the entire year including vintage. If you were to add VinWizard Load Scheduling (synchronized off-peak cooling) you would easily show a 30% to 50% reduction in refrigeration power consumption. Add some pump control and you will do even better.

PULSE COOLING BENEFITS

1. The glycol is stationary when doing its work which is more efficient than with a constant flow.
2. The glycol does not need to be as cold because of a more efficient heat transfer.
3. The return glycol is much warmer than normal and will be returned to the chiller in bursts, so the chiller works more efficiently to bring it back down to temperature.
4. The fluctuations in temperature cause convection in the tank which helps mix the product.
5. Much gentler on the wine and not so destructive to yeast.
6. No ice build-up on the inside or outside of the tank so heat transfer is much more efficient.
7. Fewer tanks are calling for coolant at any one time.

A side benefit of pulse cooling is when you have an area of the winery with reduced flow due to length of run or pipe size. As fewer tanks call for cooling at any one time you don’t need as much flow to keep the tanks cool.

PULSE COOLING HISTORY

Pulse Cooling was first brought to the attention of the industry in the late 90's by Dr. Roger Boulton, a distinguished professor at UC Davis in California. It is still used at the university winery to this day.

VinWizard is installed in the UC Davis brewing laboratory where the subject of over-chilling was raised. With 100% jacket coverage on small tanks the cold glycol kept chilling after setpoint was reached. Pulse cooling was discussed as a solution and the latest VinWizard controller was soon released with the capability.  

The system is also installed at the world-leading Bragato Research Institute in New Zealand. In September 2020 trials were held at the institute with the following results:

Essentially, the pulse-cooled method used only 30% of the energy of the conventional method, while taking twice as long to bring down the temperature. The extra time the pulse cooling took outweighed the continuous cooling when you consider the substantial energy savings.  Often, I found pulse cooling to be beneficial because it gave me more control to bring down temperatures gradually,” 

The functionality has been released at several ultra-premium facilities in the Napa region as well as wineries in Australia and New Zealand. Feedback to date has been extremely positive. The next step is to trial at a larger Australian site where power usage of the entire winery will be measured before pulse cooling and then after pulse cooling. 

Url:https://bri.co.nz/2020/10/02/pulse-cooling/

Published Date:Fri, 02 Oct 2020 01:01:23 +0000