Heat Rate Optimization Course Descriptions
7801 - Fundamentals of Plant Efficiency I
The objective of this power plant efficiency videotape is to present the basic power plant cycle and the energy conversions that take place throughout the cycle. The effect that various parameters have on the cycle efficiency are also discussed.
Upon completion of this videotape and the workbook exercises, the operator should be able to understand:
• Where energy is lost and gained in the power plant cycle.
• The use of enthalpy as a measure of energy.
• The meaning of steam quality (wetness) at the turbine exhaust.
• How to convert units of heat energy into units of electrical energy.
• How to determine turbine cycle efficiency.
• The effect of changing main steam temperature on turbine cycle efficiency.
• The effect of changing condenser back pressure on turbine cycle efficiency.
• How to determine boiler efficiency.
• How boiler efficiency and turbine cycle efficiency can be used to determine overall plant efficiency.
• The difference between gross plant heat rate and net plant heat rate.
• What factors determine boiler efficiency.
• The effect of changing main steam pressure on turbine cycle efficiency.
7802 - Fundamentals of Plant Efficiency II
The objective of this power plant efficiency videotape is to present the basic power plant cycle and discuss the energy conversions that take place throughout the cycle. The cycle and various efficiency considerations will be shown on two types of heat energy diagrams - the Mollier diagram and the Temperature – Entropy diagram.
Upon completion of this videotape and the workbook exercises, the operator should be able to understand:• The composition of a Mollier diagram and how the steam expansion through a turbine can be represented on it.
• Ideal steam expansion compared to actual steam expansion.
• Changing main steam conditions on the Mollier diagram and the effect on cycle efficiency.
• Using extraction steam for feedwater heating to increase cycle efficiency.
• How desuperheating spray water impacts efficiency.
• Basic properties of steam and water, and their reaction to heat.
• How the steam/water cycle can be represented on a Temperature – Entropy diagram.
• Changing main steam and exhaust conditions on the Temperature – Entropy diagram and the effect on cycle efficiency.
• The addition of a reheating section and feedwater heating to a Temperature – Entropy diagram and the effect on cycle efficiency.
7803 - Factors Affecting Boiler Efficiency
The objective of this videotape is to present the factors affecting Boiler Efficiency so as to increase the operator’s awareness and effectiveness. The corrective operator actions are dealt with in the videotape HRO-4.
On completion of this videotape and the associated workbook exercises the operator should be able to understand:
• Boiler Efficiency.
• The effects of variation in fuel composition on Boiler Efficiency.
• Boiler Efficiency losses associated with high and low excess air.
• The affect of coal fineness on the completeness of combustion.
• Variations in steam temperature as a function of load.
• The affect of air heaters and combustion air temperature on exit gas temperature.
• How final feedwater temperature can change the required boiler heat input.
• How air in-leakage occurs and what it might do to excess air levels.
• The problems of fireside deposits and waterside deposits.
• The significance of exit gas temperature on boiler efficiency.
• The significance of internal scaling of boiler tubes.
• The effect of silica in boiler water.
7804 - Operator Controllable Losses: Boiler
The objective of this module is to discuss how the operator can manipulate the factors affecting Boiler Efficiency (as discussed in the previous module) in order to achieve the most efficient boiler operation.
On completion of this video and workbook exercises, the participant should be able to understand the following concepts and apply them in day to day work practice.• Fuel availability at the boiler.
• Reasons for low steam pressure.
• The effect that silica content has on limiting operating pressure.
• How attemperator problems affect steam temperature.
• Using draft pressures as an indication of gas path plugging.
• How burner tilts, burner levels, and auxiliary dampers can be manipulated to adjust steam temperatures.
• How the quantity of excess air must be balanced between the effect on steam temperatures and control of losses.
• The use of sootblowing to maintain steam temperatures and the natural water circulation.
• Furnace heat transfer, convection pass heat transfer, and air heater operation.
• Control of flue gas exit temperature.
• The requirements for complete combustion, in practice.
• Minimizing air leakage into the furnace.
• How combustion air temperature can be manipulated.
• Using supplementary fuel oil for flame stabilization.
7805 - Factors Affecting Turbine Efficiency
The objective of this power plant efficiency module is to present the factors affecting turbine cycle efficiency to increase operators’ awareness of these matters and improve their effectiveness in controlling heat rate.
Upon completion of this videotape and the associated workbook exercises, the operator should understand:• The definition of turbine cycle efficiency.
• The effects on efficiency and generation for changes in throttle pressure.
• The effects on efficiency and generation for changes in main steam temperature.
• The effects that low reheat steam temperature have on efficiency and generation.
• What throttling losses are and why they occur.
• What is meant by “sliding pressure” operation and why this mode of operation increases efficiency.
• What turbine “exhaust leaving-losses” are and what role the operator plays in controlling these losses.
• The impact on efficiency and generation when feedwater heaters are removed from service or not performing properly.
• Why dissolved silica concentrations are monitored and controlled in the boiler water.
• How low reheat steam temperatures can result in damage to turbine blades.
• “Leakage” steam paths within the turbine and their impact on efficiency and generation.
• What impact generator hydrogen pressure has on efficiency and generator capability
7806 - Operator Controllable Losses: Turbine Cycle
The objective of this module is to present the actions an operator can take to correct power plant efficiency problems related to the turbine cycle.
Upon completion of this module and workbook, the operator should be able to:
• Recognize the conditions related to condenser tube fouling.
• Calculate TTD for a condenser.
• Calculate the circulating water temperature rise across a condenser.
• Take operational actions to eliminate or reduce a fouled condenser condition.
• Recognize the conditions that indicate a low circulating water flow.
• Determine the cause(s) of a low circulating water flow.
• Determine if subcooling is occurring in the condenser.
• Recognize a high back pressure problem caused by excessive “heat loading” on the condenser.
• Recognize and correct air in-leakage.
• Observe temperature limitations during start-up.
• Avoid thermal stress using “full-arc” operation and proper temperature ramp rates.
• Recognize a condition of a build-up of deposits on the turbine’s steam path.
• Be aware of the affect of increasing generator hydrogen pressure.
• Know the significance of the generator capability curve.
7807 - Balance of Plant Operation
The objective of this module is to present the factors affecting turbine cycle efficiency to increase the operator’s awareness and effectiveness in controlling heat rate.
Upon completion of this module and workbook, the operator should understand:• The reasons for heating feedwater before it enters the boiler.
• The difference between a ‘closed’ and an ‘open’ feedwater heater.
• How to calculate the ‘Terminal Temperature Difference’ (TTD) of a feedwater heater.
• How to calculate the ‘degree of approach’ for a drain cooler in a feedwater heater.
• The effect that insufficient venting has on performance of a feedwater heater.
• The effect that a high drain level will have on feedwater performance.
• The impact that bypassing feedwater heaters has on efficiency and reliability.
• The problems that can arise in the operation of the boiler as a result of inadequate feedwater heating.
• How to determine the proper amount of venting of a deaerator.
• What causes pump cavitation.
• What Net Positive Suction Head (NPSH) is and how an adequate NPSH is provided for different pumps in the power plant.
• The relationships between centrifugal pump flow, discharge pressure, power consumption and efficiency.
• How load ‘swinging’ adversely affects efficiency.
• How to improve power plant efficiency by removing certain auxiliary equipment from service at low loads.
7808 - Power Plant Control
The objective of this module is to present and discuss the factors involved in power plant efficiency control, including:
1. Adjustment of active power and reactive power output.
2. Adjustment of the primer mover and auxiliary systems to meet the power output requirement.
3. Types of plant automatic control systems.
On completion of this module, the participant will be able to understand and describe the following concepts, and include them in day-to-day work practices.
• Power system load variations.
• The need for total generating plant output to equal power system load demand plus losses.
• The effect of changes in load demand on system frequency.
• The utilization of speed (frequency) variations to initiate governor response.
• The load dispatcher’s task.
• Adjustment of governor’s set-points to control unit output.
• The effect of system overload and load rejection.
• The demand for reactive power (VARs) by consumers electro-magnetic devices.
• Production of reactive power in the generator (by adjustment of field excitation).
• The effect of increasing excitation current on:
1. Active power output (MW).
2. Reactive power output (MVAR).
3. Terminal voltage.
4. Stator current and consequent stator heating.
• Vector relationship between megawatts and megavars.
• Calculation of megavolt-amperes (MVA).
• Power factor.
• The need for sophisticated control systems to continuously adjust the steam turbine, boiler, and auxiliary equipment to meet the power output requirements of the generator.
• Modes of master control.
• The basic control loop and major components.
• Pneumatic control systems.
• Transmission of sensing signals and control signals.
• Delay due to inertia of the control air system.
• Space limitations on pneumatic control boards.
• Electronic control signals.
• Digital control systems.
• Main CPU installation.
• DCS – Distributed Control Systems.
• Multiple processors.
• The application of PLCs.
• The digital operator interface.
• Advantages of the digital control system.
power plant efficiency, boiler efficiency, turbine efficiency, operator controllable losses