Proper equipment insulation helps power plant maintenance
Have a preventive plan for shutdowns to avoid costs, save time.
Unnecessary shutdowns at power plants resulting in exponentially high costs both in terms of repair and lost hours are a constant concern for operators and managers. To avoid this kind of costly event from taking place, it is crucial that plant managers have an action plan for preventive maintenance during planned shutdowns. By having a detailed, effective plan during the anticipated shutdowns, operators can be confident that they have significantly reduced the odds of an unplanned outage.
One element of this plan should include replacing and/or installing the proper amount of insulation for the equipment operating inside the power plant. When properly insulated, benefits are quickly realized. These include some of the more obvious cost savings including energy efficiency. Operators and plant managers will also see improved equipment operating efficiency. There are also the benefits to the employees working on the plant floor.
With proper insulation, there will be significant heat reduction on the equipment itself, cutting down the risk of injury or burns to workers. There is also a reduction in unnecessary noise on the plant floor.
When installing insulation, there are several elements that managers must take into account. It begins with understanding the scope of the work that needs to be done and scheduling that work in an efficient, reliable and practical manner. Getting the proper specifications on the install should begin well before any job actually starts.
Most plants operate with a very specific maintenance budget, and this is important to understand and follow when managers begin planning and staging the materials they will need. The relationship between the contractor and the owner depends on transparency and efficiency. Extra steps in the installation process lead to extra costs. The more a contractor can save the owner through meticulous planning and follow-through, the better the relationship will become. The process begins with understanding and carefully outlining the specifications, along with the type of material that needs to be ordered.
After this is determined, a schedule of labor must be produced. In this schedule, it is important to take into consideration the time of year that the plant is planned for shutdown and install. Different times of the year will have different, specific challenges and limitations. For example, during the hot summer months, the scheduled hours for maintenance workers need to be incremental to allow for breaks so personnel can cool off and not be at risk of heat exhaustion. The correct specifications and applications of the installation are critical, to ensure that unnecessary work does not take place and time is not lost with work having to be redone. These are all factors that must be taken into account when scheduling the install.
Understanding the correct insulation specifications for the power plant equipment also is important. If the equipment is underinsulated, it will lose heat-and the electric bill for the plant will rise. On the other hand, there is a point after which more insulation will not equate to greater cost savings. By adding more thickness, more money will be spent on materials and the job will end up costing more than is required.
Many power plants were built with less-than-optimal insulation specifications. The cost savings that were supposed to be realized by many power plants do not come through as suspected. Heat escaping certain applications in the plant is a common occurrence today, resulting in less energy efficiency and, in turn, higher costs for the plants. What is the cause of this miscalculation? Simply put, most systems in the plant can become extremely hot. The temperatures can reach up to and more than 1,000° F on various systems, such as the boilers, turbines, piping and vessels. Most systems contain single-layer applications of insulation. As the industry has learned, this is not the ideal specification for typical power plants. Today, it is more efficient to install a double layer of insulation instead of one thick layer to meet the proper thickness required.
Single vs. double layer
With a single layer, the heat rate is driven up because there are more open seams in a single layer for the heat to escape. It is similar to when a person is dressing for cold weather. It is better for the individual to put multiple layers of clothes on to more efficiently hold their body temperature. The concept of insulation works the same way. When there are fewer seams in the insulation, there is less chance for heat to escape.
Many insulators are now taking the required thickness of insulation and using two layers instead of one, resulting in heat savings. Additionally, by limiting the heat that is emanating from the different applications, workers can be more productive and limit the risk of injuries—such as burns—that could lead to lost time.
Double-layer applications also can save labor. When installing double-layer insulation, the project leader can order materials in different sizes to equal the required thickness. For example, boilers and duct systems have supports that run across the system. These supports can vary in thickness. If there is a scenario where the support is three inches tall and a thickness of five in. is required, it is more efficient to install double-layer installation. The installer needs three in. of insulation to rub up against the support and another two in. to run over the support. Instead of making precise cuts that can take more labor and result in higher costs for the facility, the installer can use double-layer insulation and order a 3 inch-thick piece along with a 2 inch-thick piece. Insulation is available in multiple thicknesses. This once again speaks to the importance of planning the scope of work and the materials needed in the planning stage.
Another trend that is continually gaining steam is the installation of removable insulation pads for certain elements inside of a power plant. For equipment such as a power plant’s valves, removable pads can be far more efficient for insulation. The key benefit of these pads is that it is easily removable and reusable, resulting in a drastic cut on man-hours. As opposed to installing a permanent insulation system, the costs and time associated with removing and reusing the pads are significantly less.
Workers can to take the pad off of the insulation blanket and reuse it multiple times without the system being compromised. To get the most return on investment on the installation of insulation during the scheduled power outages at a plant, proper planning is the key driver. Understanding the scope of work and keeping the line of communication open with the contractor will save the plant money in the long run.
Winston Saunders is the insulation manager at Structsure Scaffold & Insulation, a specialty scaffolding and insulation contractor.