COOLING TOWER: PREVENTIVE MAINTENANCE AND DESCALING

Industry experts from the cooling tower industry shared their perspective about its incremental growth in sync with increasing industrial activity, discussing that preventive maintenance and chemical descaling improves cooling tower efficiency.

Cooling towers are an inherent part of a power plant’s steam cycle. Their application is of essence in power plants, especially in thermoelectric power plants to eliminate extra heat from the plant. Industries like manufacturing, growing demand for HVACR systems in air conditioning, cold storage, renewable energy power plants, and others are increasingly adopting cooling towers. 

Cooling Tower Market Size exceeded 2 billion USD in 2021 and is projected to grow at a CAGR of over 5 percent from 2021 to 2028. An increase in industrial and manufacturing activities along with the expansion of chemical, automotive, oil & gas, petrochemical, and fertiliser industries will complement the market growth. Growth for cooling towers would unlock its prospects due to the increasing construction activities in developing nations. Rapid industrial growth across developing economies; increasing demand of cooling towers in the commercial buildings and utilisation of cogeneration technologies will boost the market expansion and business growth. 

Scaling issues and new technologies for cooling towers abound in the current scenario with increasing demand especially for data centre cooling. Performance of the cooling tower is of essence along with proper maintenance periodically. Mr. Ravi Prakash, Manager, Delta Cooling Towers Pvt. Ltd., is of the opinion that remarks that a major problem that customers are facing in using cooling towers is scale. And to reduce that problem or in fact, remove that problem, one has to go to clean the proper tank which can remove scale or it can save from scale some things. Some people do chemical dosing and some of them use RO plants. 

In non chemical water treatment devices chemical dosing can be done, but manpower is used and along with that, a monetary amount each month or after every fifteen days you will have to go for that chemical dosing. The same is a problem with RO and the same is a problem with DM water. But with a non chemical water treatment device, it is one time expensive and users even just fit and forget it.

Benefits of chillers and cooling towers working together 

Be it chillers or cooling towers, they need to work together because the cooling tower outlet is the condenser water and water that is entering and takes away the heat that has been rejected. The chillers would simply cease to operate. So, they have to work in tandem. And here the cooling tower is more of a facilitator type for chillers to perform. Mr. Dipankar Bhattacharya, Country General Manager – India, DB-Aire India Pvt. Ltd., is of view that the benefits, of course, are a kind of relationship which is interdependent. And to operate chillers at its maximum efficiency, a cooling tower is also required to support that. If the losses are high, then obviously it will be implantable not delivered. And there is always a cascading effect of all these losses. So overall, they might be small in quantity, and to measure them individually, they might be very small losses. And, then the cumulative effect of that is huge. And that could be to the extent of even 30 to 40 percent. So for chillers operating efficiency versus not operating efficiency; the difference would be to the tune of 30 to 40 percent and sometimes even more, and that has been the revelation in the industry that how important it is to have both the plant and equipment, chillers and cooling tower work in tandem and that too efficiently. 

Looking at the industry, a variety of options prevail. Absolutely top notch brands are offering absolutely top class cooling towers with low approach, low losses with lower maintenance department. So, an industrial manufacturer has also come a long way in improving their design, delivering the best in class products to suit the requirements in terms of design interventions, available in the market. It’s just that some customers don’t offer high end cooling towers, because probably the initial cost involved, the upfront cost involvement is pretty high as compared to some of the ordinary cooling towers. 

Let’s say if you take the life of the cooling tower as 15 years, whatever money they have been through, that is going to be pretty high as compared to normal Capex incremental capital upfront on high efficiency. Options are pretty much available. And if customers are willing, they can invest in a high efficiency cooling tower. But, unfortunately in India, is – in India, most of the buying that happens on this page is basically evaluated. So, for certain efficiencies, probably taking more of a lifecycle approach is better. 

Mr. Ravi feels the IC motors also help in saving energy. When it comes to HVAC, as an industry, it has come of age, and when you look at some of the institutional clients, some of the captive users such as the Infosys, or the hospitality industry, are the beneficiary. So, they buy a high efficiency deployment, they get the benefit of the high efficiency throughout its life, and get the benefit on the flip side, because these industries have adopted the right kind of equipment. And, their buying criteria are always on lifecycle cost. The right quality cooling tower, which delivers high efficiency could be two to three times the cost. Still, they are investing in both because they look at it as an investment, which will save them on their operating cost and eventually, additional savings will come to them. They have not only cooling towers but also there is definitely a second cost consideration before making any buying decision. 

Further, Mr. Ravi mentions that for minimum budget required to go for installing cooling towers, the two parameters are essential to design a cooling tower firstly, the water flow rate required for your system and other the temperature variation. Manufacturing the cooling towers depends on the flow of the water. 

Especially when summer is approaching, productivity also suffers if the limited capacity of the cooling tower is there. In Spite of that, cooling towers on a rental basis is a very difficult thing to be given by anybody. you want to purchase a cooling tower or you want that on rent. Further, once you start cooling towers, you run for a couple of days. So purchasing a cooling tower is the only option. 

Mr. Dipankar adds, in the global HVAC industry, market share captured by cooling towers should be around $2 billion dollar market for cooling tower. However, Mr. Ravi says 50 percent of the production is being used for HVAC in India. In the Dubai and Kuwait area they only take cooling towers for process cooling not for HVAC, very rarely they use that but India is a big market for HVAC things and more than 50 percent of cooling towers have been supplied to the HVAC industry. 

Cooling tower water filtration system enhances performance 

For installing cooling tower, on day one the primary thing for the customer is to take care of your water quality is the view of Mr. Ravi. So, filtration is about the scale that is the major thing which is affecting the cooling efficiency of the cooling tower. The primary thing is when scale is being accumulated in the cooling tower, the filling area that is the heat exchanger media it fills, is blocked, the efficiency of the cooling tower goes on reducing day by day. If scale is saved, the quality of the water is saved, and saving the quality of water is just saving the life of the cooling tower and the efficiency of the cooling tower also. 

Relevant to the innovation, performance of the cooling tower on a sustainable basis, certain practices need to be adopted. Recent practices ensure that the new tower delivers in line with the promise that was made by certain design considerations. So to ensure that the cooling tower is delivering the performance, the most important criteria is maintenance. 

The proper measurement and verification ensure that the data is delivered in line with the design concentration. Secondly, there has to be periodical audits not only for the cooling tower, but for the entire country just to check whether this performs at an optimal level. All the parameters that are there in the design should meet and must ensure that it comes back to its optimal capacity or design capacity. 

The important thing to be considered is proper maintenance, concludes Mr. Dipankar, adding that the audits are extremely important to get the best out of cooling towers and plants and they should institute a process to ensure that it’s being carried out and at intermittent intervals.