Choosing an industrial heating system
13 March 2019
Martin Cooke, technical director for Baltur in the UK, discusses the considerations to bear in mind when selecting a replacement industrial heating system.
Unlike other sectors which are seeing an increased usage in renewable technologies, industrial heating systems do not offer the same opportunities as they still require the power of larger burners to meet substantial heat demand requirements.
However, alongside the government’s focus on reducing the amount of industry produced carbon in the UK, there has been a bigger focus on plant designers ensuring that their industrial heating systems are operating at full efficiency in order to reduce their environmental impact.
Meeting energy efficiency standards
Energy saving is one of the top priorities in the industrial market as cutting down on energy costs has a direct impact on final product costs.
With careful consideration when selecting a heating system, a huge impact on efficiency and overall environmental impact can be achieved.
When selecting a burner, it is critical to consider:
- Whether it is fully modulating instead of two-stage operation
- Whether it is pre-mix or blown gas
- Its turndown ratio (the amount a burner can increase and decrease its power across its range)
- The use of inverter driven fan motors
- If it has a low NOx combustion head (class 3 as per EN 676)
- If it has advanced combustion control, such as O2 and CO trim
All the above should be specified at the point of order. However, if controls are compatible, features such as combustion controls can often be retrofitted if required.
Energy saving can be significant when combustion control is added. For example, the Baltur TBG ME range of burners uses the BT320 Lamtec burner management system which is extremely versatile and allows extra control systems to be incorporated.
Adding CO trim to the Lamtec BT320 allows combustion systems to get closer to stoichiometric conditions safely. CO sensors use a modified version of zirconia O2 sensors, enabling them to detect products of incomplete combustion. The Lamtec CO trim is a self-learning algorithm that lasts for eight hours and then learns all over again to adapt to any changes. The trim ensures that plant is running as efficiently as possible by keeping excess air in combustion to the minimum and reducing excess heat being drawn up the flue and wasted.
People often think that implementing integrated energy saving measures will be expensive. However, by fitting technologically superior burners and controls there is potential to pay back the initial extra investment within 1-2 years and continue to save energy and reduce CO2 emissions significantly year-on-year.
Along with attaining maximum plant efficiency, the environmental impact of burning fuels must also be addressed. Nitrogen Oxide levels are an extremely important factor to consider when selecting heating equipment.
As per EN 676, gas burners are organised into three classes, with Class 3 being the lowest NOx levels up to 80 mg/KWh. All Baltur gas burner heads are class 3 as standard.
Burner to boiler matching
When a burner is matched to an industrial appliance, it is extremely important to ensure that the burners working field (the range in which the burners fan can overcome the back pressure of the appliance it’s fitted to) is looked at closely.
The information that is needed to make a perfect burner/appliance match is:
- The ‘over pressure’ of the boiler or appliance - the internal resistance of the combustion chamber that the burners fan must overcome.
- The appliance maximum heat input - the amount of heat needed to produce the required output. Losses always occur during the combustion process, so it is necessary to put more heat in than you will get out.
- Internal heat exchanger dimensions - this is important to ensure that adequate flame space is available for the combustion chamber.
- The burners ‘working field’ - the working field is the parameters in which the burner can operate within. This field is created when a burner is tested to see what resistance it can overcome within a heat exchanger and the output it is able to fire.
Overall, there are many options available to installers and specifiers when selecting burners for an industrial application which can have a considerable effect on efficiency. However, choices should not always be made based on initial cost.