Supplied by AES www . refrigerationandaircon . co . za RACA Journal I September 2024 3
News
ENERGY ASSESSMENTS PROVIDE POWERFUL INSIGHTS WHICH ‘ FUEL ’ CHANGE
It is good practice to do regular energy assessments to ensure , for example , that steam traps are working correctly , and there are no steam piping ‘ dead legs ’.
Over time , equipment deteriorates - or modifications are made with the best intentions , but not always with energy efficiency in mind , says Brenainn Cross , Technical Director at specialist operations and maintenance service provider to the steam and boiler sector , Associated Energy Services ( AES ).
When it comes to doing an accurate energy assessment , Cross says understanding a company ’ s steam offtake is vital : “ Many businesses do not realise that products use steam differently . They see steam use as a linear process , and do not appreciate that product type and mix has a big impact . There is great value for clients when they start understanding their own energy usage-related data – and AES ’ s energy optimisation capabilities , once we have the correct data ,” he advises .
This information allows AES to estimate whether or not the client ’ s thermal energy plant is fit for purpose .
Cross maintains that a lack of data – and analysis – around the conversion rate of fuel into energy is a substantial blind spot for many manufacturing or processing companies . Most focus on fuel consumption versus the quantity of product made – a process known as ‘ fuel to product out ’ costing - rather than monitoring how efficiently fuel is converted to steam energy and thereafter how much steam energy is used to produce the product .
“ We have to assess whether capital investment is required for us to meet our energy optimisation commitments accordingly .” It is therefore good practice to do regular energy assessments to ensure for example that steam traps are working correctly , and there are no steam piping ‘ dead legs ’.
While data collected regarding pressures , flow rates and temperatures is invaluable , it is often difficult to access and complete a full and detailed risk assessment of all equipment while it is operational . For this reason , boilers need to be taken offline for inspection - so that AES can raise any problems with a client and discuss ongoing asset care and maintenance ; as well as the impact thereof on the energy usage and optimisation process accordingly .
THE POWER OF CHANGE – AND METRICS Ongoing assessments are vital due to staff and management changes : “ We know the baseline situation when we take over the boiler operations and maintenance , however incoming staff and management may not . Therefore – from a perception perspective – it is very important that the client is consistently made aware of the implications were no energy assessments or optimisation to be done – and how pivotal these are to the long-term productivity and sustainability of their facility ,” he says .
Energy savings speak for themselves . An example is the 21 % and 38 % improvement respectively registered at two food processing plants where AES is responsible for energy optimisation .
For Cross , initial assessments usually identify “ low-hanging fruit ” or early energy saving gains . “ Uninsulated steam lines result in energy losses through radiation heat transfer . For a steam line with the specific parameters stated , insulating this piping would amount to a reduction in CO 2e of ~ 620 tonnes per annum ,” he says . This is illustrated as per the table below :
Nominal Pipe size 150 mm Steam pressure 10 bar ( g ) Ambient temperature 20 ° C Equivalent length of pipe 100 m
Brenainn Cross , Technical Director at AES
“ Over the past three years , we have seen increased pressure from larger clients requiring a more direct line of sight when it comes to their energy efficiencies - specifically with a view to environmental or carbon tax concerns ,” Cross observes .
He adds that AES has been asked to assess many unusual prospective fuel types , including the use of process byproduct streams as potential fuels . “ An assessment often proves that the potential energy generation does not warrant the capital expenditure required to make the fuel change ,” he explains .
Regular , accurate energy assessments really focus clients ’ attention on powerful insights which AES can then use , to make the changes required to achieve energy usage and costsavings , as well as improved environmental and operational sustainability ,” Cross concludes . RACA
Supplied by AES www . refrigerationandaircon . co . za RACA Journal I September 2024 3