4AE3 U3 C1 Obj 2.pdf

Introduction to Power Engineering • Chapter 1 Objective 2 Describe the role and duties of a Power Engineer. Power Engineers are skilled and knowledgeable workers who operate and maintain power plant equipment, including boilers. Because of their knowledge and abilities, Power Engineers are ideal c...

Introduction to Power Engineering • Chapter 1 Objective 2 Describe the role and duties of a Power Engineer. Power Engineers are skilled and knowledgeable workers who operate and maintain power plant equipment, including boilers. Because of their knowledge and abilities, Power Engineers are ideal candidates for operating sophisticated and potentially dangerous processes and process equipment. In recognition of the need for competent operators, every Canadian jurisdiction has enacted legislation mandating the role of the Power Engineer within industry. On-the-job, the activities of Power Engineers address the entire spectrum of heat generation and heat utilization processes. To make these systems function safely and economically, Power Engineers must understand equipment operation, process design requirements, and design limitations. It is usually not necessary to know all design aspects. Rather, Power Engineers must be able to comprehend and interpret design specifications, and apply this information to the operation and maintenance of sophisticated and complex controls, equipment and processes. In large plants, Power Engineers may be supervisors who direct others to safely and efficiently operate a shift. The supervised Power Engineers may be operating: • steam generators or boilers • industrial refrigeration and air compression plants • boiler water, potable water and wastewater treatment facilities • turbines, diesel engines, generators, switchgear, pumps and other equipment that utilizes, develops or distributes energy. Some of this equipment is illustrated in Figure 6. 4th Class Edition 3 • Part A 1-11 Unit A-3 • Introduction to Power Engineering and its Governance in Canada Figure 6 – Typical Equipment Operated by Power Engineers 1-12 A h i g h p r e s s u r e b o i l e r f e e d p u m p ( c o u r t e s y T r a n s A l t a 4th Class Edition 3 • Part A Introduction to Power Engineering • Chapter 1 From first to last, Figure 6 shows: • A high pressure boiler feed pump (courtesy TransAlta) • A water demineralizer (courtesy TransAlta) • An emergency power diesel generator • Control panels for emergency power • A steam turbine powered electric generator (courtesy TransAlta). In smaller plants, Power Engineers • operate and maintain equipment • maintain inventory and order supplies • prepare specifications and contracts for purchasing consumables and new equipment. Generally speaking, in smaller plants, Power Engineers assume total responsibility for the safe and efficient functioning of the plant. There may be no other staff to fulfill these roles. Power Engineers: Energy Conversion Experts Power Engineers are experts at energy conversion. An energy conversion expert is someone with a broad range of knowledge and skills, who can operate complicated equipment and processes to convert energy in its many forms, and perform these conversions efficiently, safely, and with minimal environmental impact. As Power Engineers advance in their studies and levels of certification, they become increasingly knowledgeable and adept at the efficient, safe, and environmentally responsible conversion of energy. Because of this, Power Engineers advance to take on increasingly more responsible roles. 4th Class Edition 3 • Part A 1-13 Unit A-3 • Introduction to Power Engineering and its Governance in Canada Efficient Energy Conversion To convert energy efficiently, most of the energy entering a process must leave the process, though in a converted form. For example, consider a thermal electric generating station. Using boilers, Power Engineers take the chemical energy stored in fuel and convert it to heat energy. To do this efficiently, Power Engineers monitor and control burners, and maintain proper combustion conditions. The heat energy released by the burners is converted to potential energy (steam pressure) by a boiler (a specialized heat exchanger). To do this efficiently, the Power Engineer must know how to keep the heat transfer surfaces of the boiler clean so that maximum heat transfer occurs. The Power Engineer must also be able to recognize when boiler heat transfer surfaces are becoming dirty and what to do to make them clean. The Power Engineer then converts the potential energy of the steam into mechanical energy, using a steam turbine. The Power Engineer must know how to optimize the efficiency of this energy conversion, by considering things like turbine rotor blade clearances and turbine back pressure. Finally, the Power Engineer guides the conversion of the steam turbine’s mechanical energy into electrical energy. A 500 MW thermal generating station may burn around 300 000 kg of lignite coal per hour. At $40/tonne, the production cost for fuel is $12,000 per hour. This is around 2.4¢/kWh, just to purchase the coal. An overall plant efficiency increase of only 1% results in a savings of $120 per hour, or $1 million per year! Not all plants are as sophisticated as thermal generating plants. However, Power Engineers all study the same energy conversion principles that apply in any energy plant, small or large. Through efficient operation, Power Engineers increase the plant profitability, by reducing the overall plant energy, manufacturing, and production costs. 1-14 4th Class Edition 3 • Part A Introduction to Power Engineering • Chapter 1 Safe Energy Conversion The equipment described above converts several million Joules of energy every second! The mishandling of such large amounts of energy poses immediate danger. Power Engineers develop the skills to safely operate very sophisticated and potentially dangerous equipment, including: • high-pressure boilers • pressure vessels • pressure piping systems • industrial refrigeration plants • air compressors • steam turbines • gas turbines • high-voltage electric generators • high-voltage switchgear Power Engineers recognize unsafe conditions, and intervene appropriately to ensure the safety of plant personnel and the public. In doing so, they protect plant equipment, protect the investment of their owners, and reduce corporate insurance costs. 4th Class Edition 3 • Part A 1-15 Unit A-3 • Introduction to Power Engineering and its Governance in Canada Environmentally Responsible Energy Conversion The primary result of efficient energy conversion is a reduction in energy consumption. The secondary result is the accrual of environmental benefits associated with decreased fuel consumption, including: • Reduced upstream fuel processing activities, with their own environmental impacts • Reduced fuel delivery activities and resulting emissions • Reduced consumption of treatment chemicals • Reduced stack emissions, resulting in less acid rain and climate change impact. Consider the thermal generating station once again. A 500 MW thermal station operating at full capacity may burn around 300 000 kg of lignite coal per hour. Over the same hour, this plant may produce 785 000 kg of CO2 emissions. An overall plant efficiency increase of only 1% results in a CO2 emission reduction of 7850 kg per hour, or 6.8 million kg of CO2 per year! The percent reduction applies to the emissions of acid-rain forming compounds, carbon monoxide, heavy metals and mercury as well. Operating a power plant of any size involves • being aware of waste streams • reducing waste stream quantities • treating waste streams to reduce impact on the environment Power Engineers develop expertise in all these areas. 1-16 4th Class Edition 3 • Part A Introduction to Power Engineering • Chapter 1 Power Engineers: Maintenance Experts In addition to being energy conversion experts, Power Engineers are also skilled at maintaining power plant equipment. In some Canadian jurisdictions, Power Engineers of various classifications can legally maintain and repair electrical equipment, oil burners, and gas burners, in the plants where they are employed. Some jurisdictions permit Power Engineers to certify as Industrial Mechanics or Millwrights. In other jurisdictions, Power Engineers are focused almost entirely on safe and efficient operation. In jurisdictions where Power Engineers are permitted to perform mechanical repairs and maintenance, extra “maintenance shift” rotations are scheduled. Power Engineers take turns repairing or replacing all manner of equipment, either by themselves or alongside licensed tradespeople. In jurisdictions or plants where Power Engineers are primarily operators, they still need to understand equipment and process design parameters. This is necessary to recognize when processes and process equipment are operating incorrectly. They also need to know suitable repair methods, despite not being permitted or able to perform the actual repair. For example, Power Engineers that work as boiler inspectors may be poor welders. However, they know and can identify the characteristics of good welds, and can describe proper, code-compliant procedures used in the weld repairs of boilers. Regardless of where they work, Power Engineers diagnose process abnormalities, identify faulty equipment, troubleshoot causes of equipment failure, and direct tradespeople to suitably repair and maintain equipment. Power Engineers issue work orders covering the repair and maintenance of equipment by tradespeople. Power Engineers can also coordinate the timing and planning of repairs and maintenance, and facilitate these activities by preparing equipment for servicing. Power Engineers on shift also have the authority to stop unsafe work. 4th Class Edition 3 • Part A 1-17 Unit A-3 • Introduction to Power Engineering and its Governance in Canada Historical Development of Power Engineering It is difficult to establish the date when certification of Power Engineers first began. Long before the invention of the steam engine, manual firing of furnaces was under legal scrutiny. A royal proclamation by Edward I of England in 1306 prohibited the “use of sea coals in furnaces,” and established a commission which could relax the rules in the case of careful firemen, or fine the more careless. In Germany, because of pollution problems, metal plants were scrupulously monitored, and sometimes denied the use of coal as early as 1350. The steam engine, invented early in the nineteenth century, gave mankind the first source of steady and reliable mechanical power. It was originally used to remove water from mines and thus increase mine output. For many years, it was the practice for the engines to be put together on site. The mechanics who built engines were loaned by the builder for commissioning and start up, and often remained to operate the entire power plant. Frequently they stayed with the new owner. Owners hired unskilled helpers, who started out doing manual labor, often on the coal pile. Through a system that they called “progression,” these workers were promoted to jobs with gradually increasing levels of skill as they acquired experience. As new plants were built and labour became more mobile, former employers “certified” the state of progression of a person moving to a new plant. 1-18 4th Class Edition 3 • Part A Introduction to Power Engineering • Chapter 1 In the trend toward greater efficiency, boilers were designed to operate at higher pressure. This led to serious accidents occurring due to the actions of unqualified personnel. It was natural for insurance underwriters and governments to become involved, and to take responsibility for the certification of both operators and equipment. In recent years there has been a dramatic increase in efficiency of modern plants. Close control of the steam generation process and enforcement of environmental regulations has enlarged the responsibilities of Power Engineers, demanding more knowledge and providing greater opportunity to use their talent. For Power Engineers who wish to achieve job satisfaction in this expanding technology, the learning process never ends. Nature of The Work Across Canada, and many parts of the United States, the Power Engineering profession is regulated by law. The government of the state, province, territorial or civic jurisdiction may have laws with wording similar to the following: The holder of a Certificate of Competency, the classification of which authorizes him/her to act as an engineer, may sketch, construct, install, operate, repair, and give advice on all things pertaining to any power plant in which that person is employed. The novice engineer is most likely to be involved in equipment operation and repair, until enough knowledge and experience has been gained to perform other functions permitted by local law. In very small plants, much of the work may be manually performed by the Power Engineer: • Operating valves and pumps • Observing and recording levels, temperatures, flows and pressures • Checking combustion conditions • Starting electric motors and equipment • Regenerating water softeners 4th Class Edition 3 • Part A 1-19 Unit A-3 • Introduction to Power Engineering and its Governance in Canada In larger plants, automatic control systems can perform all of these tasks. Central control rooms, like that shown in Figure 7, enable relatively few engineers to operate automated systems that, if operated manually, would require many engineers. The engineer’s function is that of an interpreter. Displayed on the control room monitors and panel mounted instruments is the information to safely control boilers, generators, industrial processes, and air conditioning equipment. On the basis of that information, changes are made automatically, or with manual operator intervention. The Power Engineer continually monitors and analyzes trends, and anticipates adverse conditions. By promptly interacting with graphical user interfaces and other electrical controls, the control room operator commands the plant to proceed with the desired “steady state” operations. The power industry has long employed automatic devices for the control of burner systems, feedwater systems and related equipment. Each new power plant employs increasing levels of automation: • increased mechanization • more reliance on automatic equipment • real-time process monitoring 1-20 4th Class Edition 3 • Part A Introduction to Power Engineering • Chapter 1 This reality does not change the need for Power Engineers. There are situations when equipment must be operated manually, and the controls used primarily to inform operator decisions (such as when warming a boiler and placing it in parallel operation with other boilers). Plants still require the presence of expert operators that know how processes and equipment should operate, when controls and instruments are being repaired, maintained, re-programmed or replaced. Power Engineers have adapted to increased automation by increasing in their understanding of control instrumentation. Figure 7 – Central Control Room (Courtesy of TransAlta) Working Conditions Power Engineers work year-round, without seasonal lay-offs, in plants that rarely shut down. Power Engineers typically work eight or twelve hours per day, in rotating shifts. They work week days, weekends, and holidays. Shifts are arranged so that at some point, several days off are grouped together in a type of “weekend”. At one time, it was common practice to operate three eight-hour shifts, starting at 8 AM, 4 PM, and midnight, with four teams assigned to these three shifts. More common now are 12-hour shift rotations. One type of 12-hour shift schedule is shown in Figure 8. 4th Class Edition 3 • Part A 1-21 Unit A-3 • Introduction to Power Engineering and its Governance in Canada Figure 8 – Typical 12-Hour Shift Pattern Plants with 12-hour shifts operate with four or five teams. Figure 7 shows a four-team schedule, with each shift assigned a letter. Follow Team A. Their shift rotation begins on a Monday morning, and lasts three day shifts. Then, they have one full day off. Team A returns on Friday for three night shifts that finish on Monday morning. Then, they are off until Thursday morning day shift. After four day shifts, ending Sunday evening, Team A has seven days off. They return the following Monday for a set of four night shifts. The schedule repeats every 28 days. With this schedule, each team puts in 168 hours over 28 days. The standard “40 hour” work week schedule is 160 hours over 28 days. Therefore, in this rotation, each Power Engineer logs eight hours of overtime each 28 day cycle. Overtime may be paid out at overtime rate, or “banked” for use as time off at straight rate, depending on the plant’s employment agreements. Other shift scenarios include “week in” and “week out” camp style deployment. This is common in locations where the Power Engineers reside a great distance from the plant, and are flown to or from a work encampment. Some 12-hour shifts have only two or three shifts in a row, and fewer days off between sets. To help promote accident-free performance, most working areas are kept clean and well-lit. Central control rooms are climate-controlled year-round. However, the plant environment is likely dirty, dusty, smoky, and noisy. Frequently, Power Engineers work in temperature extremes, confined spaces, awkward positions, and at heights, while they inspect, adjust, or repair equipment. 1-22 4th Class Edition 3 • Part A Introduction to Power Engineering • Chapter 1 Because work must be performed in close proximity to boilers, rotating equipment, electrical equipment, piping, and plant processes, Power Engineers must guard against burns and other injuries that may occur. Methods and Procedures When operating, testing, maintaining, or repairing equipment, Power Engineers must strictly adhere to the methods and practices set out in site-specific policies and procedure manuals. These manuals are developed in accordance with equipment manufacturer’s instructions and the results of job hazard analyses. The procedure manuals also incorporate efficiency considerations and environmental requirements. Power Engineers are expected to obey and participate in setting up policies and procedures, and to mentor junior employees in developing sound practices and good habits. 4th Class Edition 3 • Part A 1-23 Unit A-3 • Introduction to Power Engineering and its Governance in Canada Objective 3 Describe how shift work affects sleep patterns, diet, and overall health. Power Engineers work in facilities where production demands require the continuous operation of complex systems and related equipment: thermal power generation plants, heating and cooling plants, refrigeration plants and manufacturing plants, to name a few. Regulations demand that plants be staffed continually while in operation. While operating these plants, Power Engineers are often exposed to temperature extremes, high humidity, noise, hazardous materials, and hazardous environments. Under these conditions, Power Engineers are required to make sound operating decisions, use hand and power tools, and operate heavy equipment. Despite these adverse conditions, Power Engineers must safely and efficiently operate facility processes in accordance with company requirements. This is typical of the profession. The duration and type of work hours can influence work performance; deterioration can occur very soon after being placed on a shift schedule. The negative effects on performance can be worse in jobs like Power Engineering that require sustained attention, and extended hours. The critical importance of their role requires Power Engineers to carry out their duties with great care and precision, in accordance with established and often regulated safety standards. Being knowledgeable and alert are baseline requirements of fulfilling their role. Power Engineers must understand the many ways shift work impacts both work performance and their lives outside of work, so that they can make the necessary lifestyle adjustments to function optimally. 1-18 4th Class Edition 3 • Part A