September 24, 2015
By Mr. Arvind Surange, Follow AHRAE; PP ISHRAE & CMD- ACR PROJECT CONSULTANTS PVT. LTD.
Cold chain has been making rapid strides and is turning out to be the ‘Sunrise sector’ in India. Whereas Cold Chain involves many components such as Pack Houses, Precooling, Freezing, Storage, transport & distribution, retail etc, cold stores form the heart of cold chain. Talking about the cold storage development in India the number of cold stores have been increasing by the day & the number has grown from 83 units in 1955 to 6300 units in 2014 with the capacity growing from 53000 MT to nearly 32MMT. Indian cold storage by volume is now 131 million Cu.M and this has surpassed U.S. cold store capacity of115 million Cu.M. However, considering the population & the perishable food production we still need to atleast double our cold storage capacity.
The cold storage industry is turning into a revolution of sorts with erstwhile cold stores being of old styled potato stores while the present ones are turning out to be modern multi-product units.
Technology also is keeping pace from old bunker coil bulk units to the more efficient forced air cooling technology. Ammonia is still a better option for larger units with refrigerant pumping systems, Low charge systems & DX systems with fair component of automation. HFC’ refrigerants are currently in use for smaller units, distribution appliances & a few larger units.
Closer to our own industry, it is so happening that refrigerants, in general, are once again moving towards those used many many decades ago, but had got lost somewhere in between, owing to what we may call the ‘Freon’ revolution. The CFCs, HCFCs, HFC, etc are all generally termed as ‘Freon’ gases which have been around for many decades now. However, CFC’s are already out due to high ODP (Ozone Depletion Potential), HCFCs are also out in most countries. HFCs which are being currently used will also follow suit due to the GWP issue
Recently, the author had participated in some thought provoking seminars in USA and Europe, where the discussions were held on this very topic : “Return to the nature, Return to the natural refrigerants”. While we have been using ammonia for decades and it stood the test of time .. CO2 had disappeared as a refrigerant for many decades and has now started making its way back It may be interesting to note that a year ago, CO2 systems have shown their significant presence in Chillventa, one of the largest expositions held in Germany. Now we see that its utilization is gaining acceptance from the industry, especially in the EU nations.
We also now need to get ourselves acquainted with the newer refrigerants like HFO 1234yf HFO 1234ze, Propane (R290), R-32 etc amongst many others. Some of these have easy retrofit options and some require a completely new system.
Coming back to CO2, the fact is that while India is still at infancy with reference to CO2 as a refrigerant, the EU already has projects up and running, some for more than 7 years now. These systems can be used in cascade (Ammonia – CO2 or R134a – CO2), or in brine type pumping systems where CO2 will be effectively used as a brine.
Proper execution for high pressure systems, proper testing and oil management, etc will be the important points to take care of while execution of such a system. While it is not the intention of this article to get into deep technical details, the idea is to inform the readers of what will now be seen happening in the near and not-so-near future.
As usual, a number of events in the Cold Chain sector kept happening, including ACR TrendZ 2015 from ISHRAE Pune . Earlier ACREX, the international Expo, organized by ISHRAE had a dedicated Pavilion in Bangalore in Feb 2015 for the first time, and this will follow in future ACREX shows
Various associations have planned shows including India Cold Chain show in Mumbai in November 2015 and GCCA’s ICE 2015 in Chandigarh in December 2015.
So we are heading towards the goal for ‘An environmentally better society’ with an aim of reducing the carbon footprint that our projects put upon the earth.