In any process plant, energy in form of heat is required to carry out multiple processes. This heat is supplied using a heating medium like steam, hot water or thermic fluids. Energy audit or thermal audit helps to measure, analyze and improve the performance of utility system.
It is a common myth that energy audit or thermal audit is only about energy conservation. In reality, an energy audit helps improve the plant on various fronts like energy efficiency, reliability, productivity, product quality and safety.
Some of the important benefits of energy/thermal audits are as follows-
1. Benchmarking and evaluating potential for improvement
Analysing audit data of hundreds of plants across each industry reveals that there exists a huge difference between the fuel costs of different plants manufacturing the same product. Even the best managed plants have a further potential of saving 20%. Energy audits let the plant personnel know how efficiently their plants operate when compared with industry best plants.
Energy audits also help to understand the practically attainable savings, expenditure to attain them and the payback period.
2. Evaluation of actual performance of the utility system
Energy audits help to evaluate the actual performance of the utility system. During the course of operation, the system performance deviates from the ideal performance. A steam audit actually finds out the energy and mass balance of the system and gives actual numbers.
3. Identification of specific issues relating to process control
Each process has its own requirement in terms of heat transfer rate, temperature etc. Energy audit helps to find out if these requirements are being met or not. For instance, supplying steam at a pressure higher than required brings down the overall operational efficiency as high pressure steam has lower latent heat and forms more flash steam.
Carrying out an energy audit will help to locate and address many such process control related issues. Addressing such issues will not only bring down the fuel consumption, but will also improve the product quality and eliminate elongated batch timings.
4. Debottlenecking/ troubleshooting of recurring problems
Energy audits involve analysing recurring problems and coming up with solutions for them without compromising on other parameters.
5. Spare capacity
Carrying out an energy audit and implementing the suggested solutions can release some spare capacity which can be used to increase the production. This gives the unique benefit of increasing production without any capital investment.
6. Meeting environmental compliances and norms
In the process of energy audit, any unmet environmental compliances are brought to the notice of the plant personnel and suitable actions are suggested. This also brings down the carbon footprint.
7. Improved product quality
Issues like steam starvation, improper pressure/temperature within the process, poor condensate evacuation negatively affect the product quality. Energy audit suggestions help to resolve these issues. This improves the product quality and minimizes the rejections.