Strategic Maintenance Management in Power Generation Companies - Literature review Example

Strategic Management in Engineering Enterprises: The Role of Strategic Maintenance Management in Improving the Performance of Gas Turbine in Power Generation Companies Student Name/Number: Institution: Date: LITERATURE REVIEW Abstract In this research study we investigate the role of strategic maintenance management in improving the performance of gas turbine in power generation companies. The literature work reviews the critical points of maintenance management as it relates to gas turbines. The review covers an introduction, the use of gas turbines in power generation, and the major systems that require maintenance management, maintenance inspections and different strategies used in maintenance management of the system. Introduction Over the last two decades, power generation companies have experienced a shift from old technology steam turbine generators to gas turbine generators that use newer technology. Gas turbines play a crucial part in the power generation industry. The demand for power supply and continuously increasing competitive environment has raised the concerns over the maintenance management of power generation facilities (Eckardt, 2014). To meet these power demands while at the same time survive in the competitive environment, power generation companies have to handle maintenance management in a more efficient and effective way (Oyedepo & Fagbenle, 2011). Gas provide efficient and reliable power supply when operating optimally. The current challenge has been the overwhelming task of managing the maint enance of gas turbines. By their design and operation profile, gas turbines require a higher frequency of maintenance services compared to their predecessors. In order to maintain power distribution, the production facility must be in a good condition. These requires periodical inspections and diagnoses, parts replacements, improvements and renovations. The three resources required for maintenance are materials, manpower and equipment; they form the crucial components required in maintenance management (Salonen, 2011). Maintenance of a gas turbine a well-planned maintenance program that will ensure that power continues to be delivered under optimum efficiency and performance, while allowing for improvements to be implemented (Sulzer 2016). Although gas turbines have a relatively simple principle of operation, the components that are used in the production of energy are highly specialized, meaning that they function within very fine tolerances. Thus, any variations from the baseline performance conditions such as pressure, temperature, vibration and output require accurate maintenance before a significant damage on the machine (Fadipe & Biebuma 2010). The baseline performance data is provided by the original equipment manufacturers and is used to compare with the data obtained during a maintenance inspection. Any variations from the baseline data are collated and analyzed and put into a serviceability report with recommendations that need to be implemented for the machine to continue functioning properly. This way, maximum availability of the asset is assured and repairs can be implemented during scheduled shut-down durations. Scheduled repairs also provide an opportunity for installing improvements and upgrades that will ensure continued power supply and improved performance (Muyengwa & Marowa, 2015). The objective of this research will be to establish the role of strategic maintenance management of gas turbine in power generation companies. To achieve this, the research will seek to find out the extent of influence at which maintenance management of gas turbine has on the performance of power generation companies by considering production, quality of service and profitability. We hypothesize that well-planned maintenance management strategies can reduce operation costs, and improve power availability and reliability for power companies. The Gas Turbine for Generation of Power The use of gas turbine for power generation dates back to 1939. In modern days, gas turbines is one of the most crucial electricity generating technologies in power plants (Eckardt, 2014). A gas turbine is a type of internal combustion engine in which a mixture of air and fuel is burned to produce hot gases that are used to spin a turbine to generate electricity. It is from the hot gases produced during fuel combustion that the name gas turbine originate. Gas turbines utilize a number of fuels, including fuel oils, synthetic fuels and natural gas (Breeze, 2016). In gas turbines, combustion occurs continuously, as opposed to intermittent combustion that occurs in reciprocating IC engines. How Gas Turbines Work According to Eckardt, (2014), gas turbines have three major sections mounted on one shaft. These are the combustion chamber, the compressor and the turbine (see figure 1). They consist of multiple stages of stationery and rotating blades through which air is drawn and incrementally compressed as it goes through multiple stages (Breeze, 2016). Figure 1: A schematic diagram of the combustion chamber, the compressor and the turbine. The pressurized air is fed into the combustion chamber at very high speeds. In the combustion chamber, fuel is added to the compressed air and ignited. This further increases the temperature of air as the air-fuel mixture is burned (Kehlhofer, et al., 2009). The combustion process produces a gas stream with high temperature and pressure which moves into the turbine section at high velocity. As a heated gas stream moves into the turbine at high pressure and velocity, it expands and spins the blades in the turbine (Navrotsky, 2013). Figure 2: A typical industrial gas turbine showing the main components. Maintenance Definition Maletic, et al. (2014) define maintenance as the work undertaken to restore or preserve an equipment in a good state and efficient working during its life cycle. On the other hand, maintenance management is a technical, administrative, and financial framework for assesing and planning maintenance works on a regular basis (Muyengwa & Marowa, 2015). Salonen, (2011) describes maintenance management as the process of overseeing resource maintenance to prevent an organization from experiencing downtime or waste resources on inefficient maintenace activities. Oswald, et al., (2011) states that the key objectives of maintenance management are to efficiently schedule repair works, control costs and ensure that maintanance tasks comply with the relevant laws and regulations for standard operation of an equipment. Gas Turbine Maintenance Kurz, et al. (2013) describes maintenance management of a gas turbine as an engineering function that desires to coordinate and integrate various activities of functional areas of machine operation to achieve a common objective – continuously deliver power to consumers. According to Navrotsky, (2013), a power generation plant is labeled to be reliable, efficient and available when it performs to its optimum capabilities. Gas turbines usually undergo a series of outages during their service life, whether scheduled or unscheduled. It is the work of maintenance management unit to ensure that there is continued serviceability of the best quality to minimize the occurrence of unscheduled outages (D. Xia & Weng, 2009). Maintenance works may be on-site for some components such as shells, frames and castings, while off-site maintenance may be required for certain components that need specialized service (Janawitz, et al., 2015). Maintenance of gas turbines mainly involve three sections; the compressor system, the combustion system and the turbine. Most components in these systems are subjected to very high temperatures, stress levels and are exposed to corrosive combustion (D. Xia & Weng, 2009). Thus, maintaining these systems remain a continuous challenge during the operational life of a gas turbine. Maintenance Inspections Fredriksson & Larsson (2012) classifies turbine maintenance inspection into running, standby and disassembly inspections: Running Inspections – Sulzer (2017), states that running inspection is performed by observation of the main parameters while the turbine is in operation. This type of inspection progress from establishing the baseline operating data when a new unit is under startup and also after performing a disassembly work (Navrotsky, 2013). The baseline data serves as a reference point from where other subsequent parameter deterioration can be measured. The data is taken in order to establish parameters for normal startup and also to serve as the main steady state unit operating parameters (Janawitz, et al., 2015). Data is taken at pre-determined intervals and recorded down to allow for an evaluation of the performance of the turbine as well as the maintenance requirements as a function of turbine operating time (Eckardt, 2014). The type of data measured and recorded include: vibrational level, load verses exhaust temperature, temperature of bearing metal, fluid flow and fluid pressure, temperature of exhaust gases, pressure of lube oil, exhaust temperature spread variation, coast-down time, and startup time (Janawitz, et al., 2015). Variations from the design parameters acts as a basis for judging and rectifying the operating conditions of the unit. Standby Inspection – This type of inspection is performed in the off peaks when the gas turbine unit is not in operation (Sulzer, 2017). According to the author, standby inspection includes device calibration and routine servicing of various accessory components of the unit, including servicing the battery system, checking water and oil levels, changing filters, and cleaning relays (Kehlhofer, et al., 2009). Servicing can be carried out in the off-peak without interfering with availability. A periodic startup test is one of the most important aspects of standby inspection. A close adherence to standby inspection maintenance can significantly affect the reduction of overall maintenance costs as well as maintaining high reliability (Janawitz, et al., 2015). For a sound maintenance program, inspection and maintenance records should be kept. Disassembly inspections – Sulzer (2016) state that this type of inspection requires that the whole unit is disassembled to inspect the internal components. It is usually completed in varying levels. Disassembly inspections proceed from inspecting the combustion system to the hot gas path, to the inspection of the whole unit (Navrotsky, 2013). Maintenance Management Strategies According to Fredriksson & Larsson (2012), maintenance strategy refers to the management method used to meet maintenance goals. It defines the procedures of planned maintenance work Maletic, et al., (2014). A maintenance strategy contains scheduling information that can be assigned to a number of maintenance tasks and defines the cycle in which a specific maintainance work will be performed, and other data related to scheduling (Muyengwa & Marowa, 2015). There are a number of factors that affect the maintenance management plan for gas turbines. The key factors are highlighted in figure 3. Typically, there are five maintenance strategies used in most power generation companies. These are corrective, time-based, condition-based, reliability centered, and risk-based maintenance management strategies (Oswald, et al., 2011). Figure 3: The main factors that affect maintenance management planning for gas turbines (Source: Janawitz, et al., 2015) Strategies Used in Maintenance Management of Gas Turbines Corrective Maintenance - Oswald, et al., (2011) explains that corrective maintenance is applied to low-risk components and involves replacement of such components in case of failure. It is performed to identify and isolate a fault for the purpose of restoring the normal operation of the gas turbine system within the tolerances established by the manufacturer for in-service operations (Salonen, 2011). Depending on the maintenance management plan, corrective maintenance can be identified through a program that monitors the operation conditions of the gas turbine, or due to unexpected breakdown. Corrective maintenance carried out as a result of breakdown can either be planned or unplanned. According to Fredriksson & Larsson, (2012), planned corrective maintenance is likely to be result from a run-to-failure maintenance management plan. On the other hand, unplanned corrective maintenance could be a result of breakdown that could have been taken care of by preventive maintenance, or a breakdown resulting from lack of a maintenance management plan. Muyengwa & Marowa, (2015) affirm that many researchers have emphasized on the losses caused by corrective maintenance after breakdown. Time-based Maintenance (TBM) – Oswald, et al., (2011) describe TBM as a maintenance strategy that is employed for components with failure probabilities that depend on time. Such components are replaced after a pre-defined time interval or after a given number of cycles. This strategy is important in avoiding power plant outages and high costs of corrective or reactive maintenance (Ahmad & Kamaruddin, 2012). Time-based maintenance are always planned and budgeted for in annual allocations. However, for a time-based maintenance plan to be scheduled, the following parts are required: scheduling parameters, scheduling data, maintenance items and maintenance cycle (Sulzer, 2017). Condition-based Strategy (CBM) – Subject to continued assessment of the gas turbine unit, replacement of a component may be done depending on the outcome (D. Xia & Weng, 2009). A condition-monitoring program is used to assess the operating conditions and maintenance is triggered by the operating conditions of the gas turbine. The CBM strategy dictates that maintenance of the gas turbine unit should be performed when there is an indication of signs or reduced performance or predicted failure (Ahmad & Kamaruddin, 2012). Checking a gas turbine unit for indicators of reduced performance may include visual inspection, non-invasive measurements, scheduled tests and performance data. The data gathered is used for preventive maintenance (Sulzer, 2017). Reliability-centered Maintenance (RCM) – Salonen, (2011) defines RCM is a maintenance management strategy that is used for optimization of maintenance resources based on the reliability of a component. The approach of this strategy is the implementation of a given maintenance activity on each of the components in the gas turbine unit in isolation (Guevara & Souza, 2008). The maintenance activities implemented are optimized to ensure that the plant’s electrical energy production is maintained using cost-effective techniques. According to Fredriksson & Larsson (2012), RCM program is guided by the following principles: The main objective is to ensure continued operation of the gas turbine unit with minimal interruptions. Identification of failure modes that are likely to affect the normal operation of the unit. Prioritization of failure modes. Selection of applicable techniques to control the identified modes of failure. Figure 4 presents an overview of RCM as illustrated by Pride (2011). Figure 4: Overview of RCM (Source: Pride, 2011) Risk-based Maintenance (RBM) – With this framework, maintenance of different components is prioritized based on reliability and importance (Pride, 2011). RBM strategy prioritizes maintenance of components with the highest risk in case of failure. It is a cost-effective strategy as it seeks to determine the most economical way of using resources. Kurz, et al., (2013) explains that the purpose of RBM approach is to optimize maintenance efforts while minimizing the risk of unit failure. Oswald, et al. (2011), affirm that ccorrective, time-based and condition-based strategies enable a power generation company to maintain peak power availability, while reliability-centeredness and risk-based strategies help the company to lower its costs. This substantially contributes to the overall profitability and business competitiveness of the enterprise (Maletic, et al., 2014). Figure 5 below shows the relationship between the five strategies, asset availability and maintenance cost. Figure 5: The relationship between the five strategies, asset availability and maintenance cost (Source: Oswald, et al., 2011) Maintenance and Its Role in Company Performance According to Maletic, et al. (2014), the significance maintenance management has increased over the years due to its impact on areas such as production, quality and profitability. The authors explain that effective maintenance management strategies contribute to company performamce by adding value through efficient utlilization of resources, enhancing product quality, and reducing downtime. Maintenance and Production The main task of a power generation company is to continuously produce electricity and deliver to the users with minimal interruptions. Nevertheless, according to A.A.Fadipe & Biebuma (2010), efficient maintenance management strategy influences the production capacity of the power plant. Thus, strategic maintenance is viewed as a function that works parallel to production and affects production by increasing the plant’s production capavity while controlling the output (Kehlhofer, et al., 2009). Maletic, et al., (2014) argues that although the literature has pointed out the role of maintenance in meeting production objectives, there is still more to be done to integrate maintenance and production. The authors relate this to the fact that maintenance is percieved as a limiting constraint and the problem is how to accomplish production master shedule in an environment under constrained management. Maintenance and Quality Quality of product service is the main edge for competitiveness and profitability in mordern global economy (Maletic, et al., 2014). Thus, the role of maintenance in this endeavor cannot be overemphasized. In specific, regular breakdown of gas turbine suystem due to poor maintenance experiences loss of optimum performance. Thus, effecting power supply to consumers. The authors affirm that this can drive the power production process out of control which may also affect the production cost and put the company at financial risk. Maintenance and Profitability According to Muyengwa & Marowa (2015), profitability relates to production cost and cost recovery. The author concedes that when evaluating profitability, it is also important to measure the impact on other areas such as equipment life-cycle profit. In a wider view, maintenance seeks to lower the cost of operation and improve power availability (Janawitz, et al., 2015). Thus, it may be important to evaluate the cost effectiveness of each maintenance action in terms of relevant cost constraints after and before maintenance works. Maletic, et al., (2014) explain that low cost and differentiation are the main generic ways to achieve competitive advantage in reaction to external factors. Low cost can be acived by economies of scale, uptight cost control, and minimizing the cost of support activities such as maintenance. Conclusion Maintenance management has become part of integrated business concept as many companies become aware of the impacts it has on the performance of their organizations. It is critical that efficient maintenance strategies are put in place for gas turbine systems to ensure that there are minimal interruptions to power supply, with the plant operating at its optimum. Implementation of appropriate maintenance management strategies can reduce the total operational cost of the company while also ensuring that the company remains competitive in the industry. References Read More