Upgrading large facility pool boilers for energy-efficient and consistent heating

2. 

   Reducing the size of individual heat exchangers

In addition to diminishing the overall heat transfer capacity of the heating system, resizing individual heat exchangers yields several advantages. This may necessitate an increase in the number of heat exchangers, but this change is insignificant.

Smaller heat exchangers offer simplified installation and maintenance. For instance, during the last replacement of large heat exchangers with smaller units, the required servicing personnel decreased from four individuals to just one.
In addition, the process no longer requires rigging and heavy equipment to extract the tube bundle from the shell, presenting a safety advantage. The size and weight of the heat exchanger components are far less likely to cause substantial damage if accidentally dropped.

Another benefit of employing smaller heat exchangers is models with a capacity of less than 400,000 BTUh do not mandate American Society of Mechanical Engineers (ASME) inspections every other year, which typically cost around $200 per unit. This cost factor becomes especially significant for large facilities that encompass a substantial number of large heat exchangers, such as the 27 units maintained by the author’s company in a single facility.

Finally, the installation of numerous smaller heat exchangers introduces an element of redundancy, safeguarding against potential maintenance issues or the failure of a single unit.

3. Selecting the highest-performance heat exchanger material

When the author’s company undertakes the replacement of shell-and-tube heat exchangers, they offer customers two material options: steel construction with cupronickel coil bundles or a fully titanium unit. Based on their experience, the steel units typically have a lifespan of five to seven years. In contrast, a properly maintained titanium heat exchanger is expected to last a lifetime.

In terms of cost, a titanium model is approximately 50 per cent more expensive than a steel model. However, the steel units are accompanied by a two-year warranty, while the titanium units come with a 10-year warranty. Essentially, customers pay a 50 per cent premium for an 80 per cent extension in warranty coverage when they opt for the titanium model.

At larger facilities, the company strives to employ the same model of heat exchangers wherever possible, which allows for the stocking of common parts. This practice is instrumental in minimizing downtime in case of a failure.