Water/Steam Treatment Programs and Chemistry Control for Heat Recovery Steam Generators

2013 ◽  
Author(s):  
Brad Buecker
Keyword(s):  
Heat Recovery ◽  
Power Plants ◽  
High Reliability ◽  
Combined Cycle ◽  
Steam Treatment ◽  
Steam Turbines ◽  
Steam Generators ◽  
Accelerated Corrosion ◽  
Boiler Water ◽  
Water Steam

New power generation in the U.S. is being dominated by installation of combined-cycle power plants, where a significant portion of the power is produced from steam turbines supplied by heat recovery steam generators (HRSG). Proper chemistry control and monitoring of HRSG feedwater, boiler water, and steam are essential for high reliability and availability of these units. However, many plants have minimal staff, most if not all of whom have no formal chemistry training and who may not fully understand the importance of water/steam chemistry and monitoring techniques. This paper provides an outline of the most important chemistry control methods and also examines the phenomenon of flow-accelerated corrosion (FAC). FAC is the leading cause of corrosion in HRSGs,[1] and is often the result of the outdated belief that oxygen scavengers are a requirement for feedwater treatment. Since 1986, FAC-induced failures at several coal-fired power plants have killed or injured a number of U.S. utility workers.

scholarly journals Gas Turbine Heat Recovery Steam Generators for Combined Cycles Natural or Forced Circulation Considerations

1988 ◽  
Author(s):  
Akber Pasha
Keyword(s):  
Gas Turbine ◽  
Steam Generator ◽  
Heat Recovery ◽  
Power Plants ◽  
Natural Circulation ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Steam Generators ◽  
Forced Circulation ◽  
Gas Turbine Exhaust

In recent years the combined cycle has become a very attractive power plant arrangement because of its high cycle efficiency, short order-to-on-line time and flexibility in the sizing when compared to conventional steam power plants. However, optimization of the cycle and selection of combined cycle equipment has become more complex because the three major components, Gas Turbine, Heat Recovery Steam Generator and Steam Turbine, are often designed and built by different manufacturers. Heat Recovery Steam Generators are classified into two major categories — 1) Natural Circulation and 2) Forced Circulation. Both circulation designs have certain advantages, disadvantages and limitations. This paper analyzes various factors including; availability, start-up, gas turbine exhaust conditions, reliability, space requirements, etc., which are affected by the type of circulation and which in turn affect the design, price and performance of the Heat Recovery Steam Generator. Modern trends around the world are discussed and conclusions are drawn as to the best type of circulation for a Heat Recovery Steam Generator for combined cycle application.

An Impact of Environmental Disturbances on Combined Cycle Power Plant Control

2004 ◽  
Author(s):  
Zygfryd Domachowski ◽  
Marek Dzida
Keyword(s):  
Power Plant ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Power Plants ◽  
Ambient Pressure ◽  
Combined Cycle ◽  
Steam Generators ◽  
Environmental Disturbances ◽  
Power Plant Control ◽  
Plant Control

Combined cycle power plants operate at thermal efficiency approaching 60 percent. In the same time their performance presents several problems that have to be addressed. E.g. gas turbines are very sensitive to backpressure exerted on them by the heat recovery steam generators as well as to ambient pressure and temperature.

How Combined Cycle Configuration is Impacted by Current Power Market Requirements

2012 ◽  
Author(s):  
Justin Zachary
Keyword(s):  
Power Generation ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Power Plants ◽  
Spare Parts ◽  
Combined Cycle ◽  
Lessons Learned ◽  
Steam Turbines ◽  
Equipment Selection ◽  
Plant Configuration

In the past 20 years, the equipment manufacturers have made significant strives to develop better and more cost effective products: gas turbines, steam turbines, Heat Recovery Steam Generators (HRSG), water treatment, fuel treatment equipment etc. Consequently, the Combined Cycle Power Plants (CCPP) have become, due to many technological breakthroughs, the most efficient form of electrical power generation from fossil fuel, reaching or exceeding net efficiencies of 60%. We are also witnessing a substantial penetration of Renewable in the power generation mix. The Renewable intermittent nature of generation associated with new grid requirements for spinning reserves and/or frequency control must be considered when new CCPP are conceptually designed. The paper will examine several CCPP configurations, involving one, two, and three gas turbines. Substantial improvements in the efficiency are usually associated with an increased gas turbines electrical output. Various scenarios of plant configurations with targeted, sensible level of integration will be examined. The challenges of major equipment selection (gas turbines, heat recovery steam generator steam turbines, heat sink) for each of the configurations will be examined from an EPC (Engineering, Procurement, Construction) Contractor perspective, based on the lessons learned from the development and execution of more than 30 advanced CCPPs. A special emphasis will be given to the strategy of providing the CCPP with fast start-up, capability, rapid load changes, without negatively impacting part-load efficiencies and emissions. The effect of plant configuration on plant reliability, maintenance requirements and recommended spare parts will also be discussed. Finally the paper describes the lessons learned, in plant configuration selection that can be successfully employed on future projects through judicious equipment selection at the development phase, design optimization and proper project management at the execution phase.

40 Years of Combined Cycle Power Plants

2002 ◽  
Author(s):  
Lothar Balling ◽  
Heinz Termuehlen ◽  
Ray Baumgartner
Keyword(s):  
Power Generation ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Power Plants ◽  
Combined Cycle ◽  
Steam Generators

Even though the first installations of combined cycle power plants with heat recovery steam generators (HRSG’s) are only about forty years old, the first attempt to build gas turbines for power generation was made more than 100 years ago. It took however about 40 years before gas turbines were installed to supply peaking power.

Design Principles and Sizing Approach of Unfired Once-Through Steam Generators

2011 ◽  
Author(s):  
E. Hamid ◽  
M. Newby ◽  
P. Pilidis
Keyword(s):  
Heat Transfer ◽  
Power Systems ◽  
Heat Recovery ◽  
Power Plants ◽  
Design Principle ◽  
New Technology ◽  
Combined Cycle ◽  
Steam Generators ◽  
Scaled Model ◽  
Flow Rates

One of the key elements of increasing the thermal efficiency of a combined cycle power plant (CCPP) is to improve the design and operation of the heat recovery steam generators (HRSG) utilized in the cycle. Once-through steam generator (OTSG) is a new technology introduced for heat recovery in power systems. It eliminates boiler drums and other components of conventional HRSGs. The simplicity and compactness of an OTSG justifies its application in combined cycle power plants. This paper describes a design principle and an analytical sizing approach that will assist OTSG’s designers to achieve a good design by determining the core dimension, volume of an OTSG for given flow rates and their entering and leaving temperatures as well as the heat transfer area on the smoke side. The developed model has been tested with reference to a scaled model of an existing OTSG that is installed at Manx Electricity Authority and the results were promising. The overall characteristics of heat transfer and pressure drop distributions of the OTSG “scaled model” shows general agreement with the real characteristics of the existing OTSG with error values less than 1%.

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