Tips to Improve Boiler Operating Efficiency
Close to 40% of all fossil fuel burned by industry is consumed in steam production. Simple steps can have a large operational impact on the cost of fuel, water, treatment, and labor.
Here are four strategies for improving boiler operating efficiency to ensure cost saved.
1. Maintaining A Clean Heat Exchanger
Clean boiler heat exchange surfaces allow for maximum heat transfer from the burning fuel to the boiler water. Feedwater quality is critical to prevent deposit formation within the boiler and maintain peak efficiency. Water-side deposits will insulate heat exchange surfaces and sharply increase fuel consumption. Regular monitoring of water chemistry and critical operating parameters (i.e. stack, tube, or coil temperatures) is recommended to provide early indication of fouling. Visual inspections of the water-side of a boiler should also be performed to ensure the effectiveness of the current treatment program.
2. Automating Boiler Blowdown
The production of steam in a boiler leaves behind dissolved and suspended solids in the water. These solids accumulate with continued steam production necessitating regular blowdown of boiler water. The boiler water that is removed during blowdown has been chemically treated and heated to operating temperature. As a result, excessive boiler blowdown increases the treatment, fuel and water costs. Too little boiler blowdown can cause carry over of boiler water in steam also resulting in excess fuel and chemical consumption. The installation of an automated blowdown control system allows for active monitoring of the boiler conductivity and optimizes the volume of blowdown based on fluctuating steam loads. A well designed automated blowdown system will lead to increased boiler efficiencies and promote improved steam quality.
3. Maximize Condensate Return Rate And Temperature
Returning high temperature condensate will reduce the cold water make up rates and save on water, energy, and treatment costs. Since condensate typically contains low levels of dissolved solids, it will also reduce the required blowdown rates providing further savings. Maximizing the energy in the condensate that is already being returned is another consideration. Returning pressurized condensate will reduce the flash losses and increase the overall energy savings. Insulation of the return piping will also minimize heat losses to the environment.
4. Metering And Benchmarking Utility
Though the installation of meters on a steam system may not directly impact the efficiency of a boiler, the data they collect will allow you to gain insight into the current operating conditions and provide a clearer understanding of the overall cost of steam production.
With the availability of the usage data from metering, opportunities for improved steam plant efficiency can be identified and quantified.