Plant & Works Engineering
Industrial boilers: upgrade or replace?
Published:  13 August, 2015

Given the expected life expectancy of an industrial boiler, it can be difficult to find justifiable reasons to invest in modernising or even replacing entire systems during their life cycle to enhance energy efficiency. Rob Brown, technical manager for Industrial Boilers at Bosch Commercial and Industrial Heating, emphasises the importance of a detailed site survey before any decisions are taken and discusses some of the upgrade options available.

The investment in an industrial boiler plant will never be one that can be made without an in-depth analysis of performance and, more significantly, the payback period. While a typical boiler system can often be relied upon to stand the test of time over the course of multiple decades, advancements in technology mean it is often pertinent to consider upgrading or replacing systems before the end of their natural life in order to maximise efficiency.

As with any energy system, including industrial plant rooms, there is no such thing as ‘one solution fits all’. It is important to remember that the system in place today may not just require a like-for-like swap, and it is vitally important to consider wider implications. Have the site’s requirements changed since the original system was installed? Are there more modern technologies on the market today that may prove to be a better solution than what was available at the time? Answers to both of these questions could prove fundamental to the future of the plant.

Taking a low temperature system as an example, it may be that a Combined Heat & Power (CHP) module can be installed, which essentially gives a boiler plant free heat alongside electricity generation. In other cases, it could be that the site doesn’t have very many hand wash basins, which lends itself to the installation of direct water heaters. Regardless of the circumstances, it’s important to look at the full plant requirements, as well as whether or not the site has the potential for a packaged boiler house. For example, it may lend itself to small de-centralisation and or point of use steam generation which can be achieved with a containerised solution.

A pre-packaged solution

In the event a site does require a new boiler, it is very rare that the investor will want to construct a brand new building to house the system, so investing in a boiler housed in a container often proves to be the favoured option. This doesn’t tend to be because of the size of the boiler or the initial outlay required, but due to the fact that a new building is unable to be constructed to accommodate it.

The convenience of the containerised solution is that the investor can have a boiler delivered and installed in an appropriate location on site for point of use, close to the process application requiring the heat or steam output.

There are a number of different reasons for stakeholders opting for a containerised solution. It may be that they only have one boiler on site and need another to cater for additional output following a change of requirements. Alternatively, in the case of a steam boiler, it may be that the requirement for a statutory shutdown makes it more practical to have a containerised solution. There are many different reasons why the flexibility of a containerised boiler house can prove hugely beneficial in certain circumstances.

It may be that in an application such as a dye works, where the tanks need to be pre-heated in the early part of the day, before the process takes place. In these cases, it can be quite common for the boiler on site to have been vastly oversized for its requirements, so a containerised solution can be better sized, and located closer to the point of use with appropriate controls to maximise efficiency.

Taking control

When it comes to controlling modern systems, boilers can be turned both on and off remotely through a Building Management System (BMS), which in turn has significant cost saving benefits – particularly when it comes to labour. With a BMS that allows the remote control of the boiler system, there is no need for someone to be on site during the night or the early hours of the morning in order to fire it up before a day’s use. Not only is it possible for the boiler to be controlled remotely, but it is also possible for the boiler to monitor its own performance to ensure it is operating correctly.

When upgrading a heating or hot water system on site, it is becoming increasingly advantageous to speak to a manufacturer or supplier that can offer a wide range of different technologies rather than being a specialist in one area. The largest cost-savings generally follow a site survey which is unbiased towards a particular technology and its suitability for the job.

There will become a point at which the best option may be to combine multiple technologies, working together to cater for the entire heating, hot water and process heating requirements. Using a steam boiler alongside a CHP module, a system would effectively be capable of delivering free steam, domestic heating and hot water, and secondary heat – not to mention electricity. Some of the older factories in the country still tend to generate their facility’s heat from the central boiler house, using steam – hot water calorifiers for radiators and hand wash outlets. When you break everything down and separate the heating and hot water usage from the process heating requirements, it can be more cost-effective to install a smaller, separate system to cater for hand wash basins and other non-process heating requirements.

Ultimately, the key to maximising the boiler performance on a given site – whether for hot water or process heating – is to conduct a thorough site survey before any work takes place. It is vitally important to understand the requirements of the people and processes on site before any decisions are made on product selection.”

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