FEATURE
INCORPORATING COLD CHAIN
unsustainable for businesses. As a result, air-cooled and adiabatic cooling systems are increasingly being considered as an alternative solution. Over the past year alone, the number of companies that have included adiabatic upgrades into their budget for the next financial year, has increased considerably.
ADIABATIC ALTERNATIVE
Replacing the evaporative condensing units in a refrigeration system with adiabatic cooling can reduce water consumption by up to 75 %. In evaporative condensing, water vapour is passed directly over pipes containing refrigerant, which requires a constant supply of fresh water. Adiabatic is somewhat more complex. The refrigerant, in a finned dry heat exchanger, is condensed by air that has been pre-cooled through the evaporative process. To save water, the adiabatic cooling of the air is only started once the ambient air temperature reaches a predetermined set point.
Even when there is no water at all, adiabatic systems will continue to enable operation of the plant at a somewhat reduced capacity. In the case of evaporative condensers, a complete loss of water supply will result in the plant stopping almost immediately.
CONSIDERING THE COSTS OF OPERATION
Adiabatic and air-cooled systems require more space and consume more electricity than purely evaporative condensing. While an increasing number of companies in the Western Cape are willing to make that trade-off to decrease their water risks, we find that businesses in regions without water restrictions still see the increased cost implication as a stumbling block.
Pixabay
John Ackermann
Regardless of the system being implemented, most businesses are paying more than they should for their refrigeration and implicitly for the increased water consumption thereof.
Typical evaporative condenser commonly used in large industrial refrigeration plant and that has high water usage.
The ongoing drought in the Western Cape has made people more aware of the amount of water they use, especially in refrigeration systems.
However, the increase in energy use can be minimised. There are ways to work around the higher electricity requirements, starting with more advanced control processes as well as redirecting and utilising the waste heat produced by the system.
Regardless of the system being implemented, most businesses are paying more than they should for their refrigeration and implicitly for the increased water consumption thereof. Maintaining the refrigeration system is a major cost factor for a company to consider, and it can be argued that most businesses only intervene or conduct maintenance on their refrigeration when it has broken down.
The reason for this is that the efficiency of the system is actually exceedingly difficult to measure. Most businesses only realise that there is an issue with their refrigeration system’ s efficiency when they receive their electricity bill, and then the cause is not always clear. Often the problem develops so gradually that it takes months to identify. Being able to quantify the amount of refrigeration achieved per kilowatt hour would allow a system operator to identify issues in a system much sooner, but the equipment required to do this have so far been prohibitively expensive.
With this in mind, Energy Partners Refrigeration has developed its own refrigeration meter system to address this challenge. At its core, it is a mathematical algorithm that uses live temperature and pressure data from the plant to simulate the real process. We have managed to make the cost of the meter low enough so that we can install it on all our systems. The meter allows operators to track the system’ s performance in real time, as opposed to monthly.
FUNDING SYSTEM UPGRADES
Energy Partners Refrigeration has spearheaded a business model that allows companies to pay for refrigeration as a utility without owning the system. Basically, we install, manage, and own the refrigeration system on site, while the client only pays for the refrigeration that they use, at an agreedupon rand-per-kilowatt-hours-refrigeration( R / kWhR) rate. At the moment, we are one of only a few service providers in the country to offer this product.
This outsourced model is increasingly being embraced by large corporates in the food and beverage sector. Where we used to see the larger companies opting to own and operate their own systems, more and more potential clients are showing interest in the outsourcing model, since it has proven to be much more cost efficient and less labour intensive on the part of the client.
Alternatively, Energy Partners Refrigeration is also able to offer its clients lease agreements.
THE RISK / COST BALANCE
Even though the water risks in other parts of the country are still less severe than in the Western Cape, I predict that reducing water consumption will become crucial for many more businesses over the coming years. The drought in the Western Cape is just the beginning and water security is increasingly becoming a risk that businesses across the country need to manage.
At the same time, the electricity costs for businesses in South Africa continue to rise at above-inflation rates, increasing the need for companies to ensure that they are operating their systems at the highest possible levels of efficiency.
The rest of the continent is also starting to move towards this way of thinking. We are beginning to receive interest from a number of large corporates in other African countries that are looking for solutions to decrease both their water and electricity consumption.
With the pressure on resources mounting every year, and businesses becoming increasingly aware of their part in becoming more responsible, efficient refrigeration will become the food and beverage industry’ s most important priority in the pursuit of sustainability. CLA
COLD LINK AFRICA • June 2018 www. coldlinkafrica. co. za 41