Advances in Power Plant Steam Blow Cleaning Analyses

2004 ◽  
Author(s):  
Julie M. Jarvis ◽  
Paul J. Babel ◽  
Allen T. Vieira
Keyword(s):  
Power Plants ◽  
Dynamic Pressure ◽  
Turbine Blades ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Steam Power ◽  
Steam Power Plants ◽  
Design Coordination ◽  
Modeling Techniques ◽  
Coal Power Plants

Steam blows are used prior to initial turbine powering for steam power plants to clear debris and surface scale that could potentially damage turbine blades during plant operation. Based on experience from steam blows for several dozen plants, enhancements have been made to the techniques in the detailed engineering analysis used by plant startup to perform steam blows. This paper discusses these improvements as applied to combined cycle gas and coal power plants. The basis for steam blows is that the piping is blown, bypassing the turbine, with sufficient boiler pressure to ensure that the piping will experience a dynamic pressure to assure adequate cleaning. Typically, the boiler pressures during steam blow provide a dynamic pressure throughout the piping, which is at least 20% higher than would be experienced for all plant operating conditions. Therefore, any potentially damaging particles will be blown out of the piping prior to the turbine operation. The following improvements and enhancements, which are detailed in this paper, have recently been implemented in the analyses used to establish adequate steam blows: 1. Advanced Modeling Techniques. 2. Design Coordination with Fast Track Engineering. 3. Consideration of Multiple HRSG Plants. 4. Analysis Support During Actual Steam Blows (for site engineering and startup).

Performance Analysis of a 565 MW Steam Power Plant

2011 ◽  
Author(s):  
R. Chacartegui ◽  
D. Sa´nchez ◽  
J. A. Becerra ◽  
A. Mun˜oz ◽  
T. Sa´nchez
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Operating Conditions ◽  
Feed Water ◽  
Water Heater ◽  
Turbine Generator ◽  
Steam Power ◽  
Steam Power Plant ◽  
Water Heaters ◽  
Steam Power Plants

In this work, a tool to predict the performance of fossil fuel steam power plants under variable operating conditions or under maintenance operations has been developed. This tool is based on the Spencer-Cotton-Cannon method for large steam turbine generator units. The tool has been validated by comparing the predicted results at different loads with real operating data of a 565 MW steam power plant, located in Southern Spain. The results obtained from the model show a good agreement with most of the power plant parameters. The simulation tool has been then used to predict the performance of a steam power plant in different operating conditions such as variable terminal temperature difference or drain cooler approach of the feed-water heaters, or under maintenance conditions like a feed-water heater out of service.

scholarly journals Up-Rated Reheat Gas Turbine for the Repowering of Steam Power Plants

1999 ◽  
Author(s):  
G. Negri di Montenegro ◽  
A. Peretto ◽  
E. Mantino
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Fossil Fuel ◽  
Lower Cost ◽  
Combined Cycle ◽  
Internal Rate Of Return ◽  
Steam Power ◽  
Steam Power Plants ◽  
Combined Cycles ◽  
Fossil Fuel Power Plants

In the present paper, a thermoeconomic analysis of combined cycles derived from existing steam power plants is performed. The gas turbine employed is a reheat gas turbine. The increase of the two combustor outlet temperatures was also investigated. The study reveals that the transformation of old conventional fossil fuel power plants in combined cycle power plants with reheat gas turbine supplies a cost per kWh lower than that of a new combined cycle power plant, also equipped with reheat gas turbine. This occurs for all the repowered plants analyzed. Moreover, the solution of increasing the two combustor outlet temperatures resulted a strategy to pursue, leading, in particular, to a lower cost per kWh, Pay Back Period and to a greater Internal Rate of Return.

scholarly journals Application of a Hot Air Turbine for Efficiency Improvement in MHD/Steam Power Plants

1979 ◽  
Author(s):  
Stewart Way
Keyword(s):  
Power Plants ◽  
Combined Cycle ◽  
Steam Boiler ◽  
Efficiency Improvement ◽  
Steam Power ◽  
Design Concepts ◽  
Steam Power Plants ◽  
Hot Air ◽  
Air Turbine ◽  
Flow Division

It is possible to gain 2 percent to 3 percent efficiency points in the MHD/steam combined cycle by application of a hot air turbocompressor. This gain is accomplished without any increase of air preheat temperature. Moreover, the size of the steam boiler and turbines in the bottom plant is reduced In the arrangement here proposed, all the compressed and preheated air expands through the turbine, rather than having a flow division as in older design concepts.

scholarly journals Boosting Steam Plant Thermal Efficiency and Power Output Through the Addition of Gas Turbines

1987 ◽  
Author(s):  
M. J. J. Linnemeijer ◽  
J. P. van Buijtenen ◽  
A. U. van Loon
Keyword(s):  
Power Output ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Steam Power ◽  
Power Stations ◽  
Steam Power Plants ◽  
General Terms ◽  
Utility Companies ◽  
Steam Plant

This paper describes the conversion of existing conventional steam power plants into combined cycle plants. A number of Dutch utility companies are currently performing or planning this conversion on their gas-fired power stations, mainly in order to conserve fuel. Modifications of boiler and steam cycle, necessary for the new concept, are presented in general terms, together with a detailed description of one of the projects.

scholarly journals Vertical Design HRSG With Natural Circulation Successfull in Operation

1997 ◽  
Author(s):  
D. Rath ◽  
A. Koller
Keyword(s):  
Power Plants ◽  
Waste Heat ◽  
Natural Circulation ◽  
Circulation Type ◽  
Combined Cycle ◽  
Assisted Circulation ◽  
Steam Power ◽  
Steam Power Plants ◽  
Steel Mills ◽  
The Sixties

At the beginning of the Sixties the concept of Combined Cycle Power Plants (CCPP) was introduced to the market in parallel to the Standard Steam Power Plants. Based on the experience of Waste Heat Boilers, built behind the blast oxygen furnaces of steel mills, Heat Recovery Steam Generators (HRSG) with forced or assisted circulation as well as of the natural circulation type were developed. The latest version of HRSG’s, the vertical type with heating surfaces horizontally arranged and natural circulation only, was put into succesfull operation in 1995. Development and experiences shall be presented.

Design Possibilities and Performance of Combined Cycle Operation of Converted Steam Power Plants

1988 ◽  
Author(s):  
M. J. J. Linnemeijer ◽  
J. P. Van Buijtenen
Keyword(s):  
Power Plant ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Steam Power ◽  
Steam Power Plants ◽  
Power Increase ◽  
Efficiency Increase ◽  
And Performance ◽  
Unit Performance

An interesting method for “boosting thermal efficiency and/or power output of an existing steam power plant is repowering through the addition of gas turbines. The forced draught fan is replaced by a gas turbine and the air heater by low-temperature economisers. This conversion will change the performance of the installation significantly. Therefore the design of the existing installation has to be reviewed based on new unit performance calculations. Since the conversion has to be economical, it is important to find a good compromise between investment and improvement of performance. This paper describes the change in performance of the installation created by the conversion in general and a number of design possibilities based on the experience gained with the realisation of a number of conversion projects. These projects show a possible efficiency increase of over 10% and a power increase of up to 30%.

Comparative Thermoeconomic Analysis Between Combined Cycle Units Derived From Existing Steam Power Plants and a New Combined Cycle Plant

1998 ◽  
Author(s):  
G. Negri di Montenegro ◽  
A. Peretto ◽  
E. Mantino
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Pressure Level ◽  
Combined Cycle ◽  
Steam Turbines ◽  
Steam Power ◽  
Steam Power Plants ◽  
Combined Cycle Plant ◽  
Combined Cycles ◽  
The Cost

In this paper, a thermoeconomic analysis is carried out for two and three pressure level combined cycles derived from existing steam power plants. The considered steam power plants are among the most widespread in the Italian territory (70 MW, 160 MW, 320 MW power output). First of all, the gas turbine plants that best match the steam power plants’ requirements are selected among existing units. Subsequently, the thermodynamic analysis for the repowered plants is performed, taking into account the off-design working condition of some components such as, the steam turbines and the condenser. Then, the economic evaluation for the repowered plants is carried out by determining the cost per kWh, the pay back period and the internal rate of return. The analysis permits the most economic choice to be made. The thermoeconomic investigation was also performed for a new combined cycle power plant. The study has revealed that the repowering of the three existing steam power plants in two or three pressure level combined cycle plants is more convenient than building a new combined cycle with higher efficiency. It has also pointed out that the repowering of the 320 MW existing steam power plant in a three pressure level reheat combined cycle plant supplies the lowest cost per kWh among all the other repowered plants analyzed. The revamping and environment effect on the above mentioned existing steam power plants was also investigated and it resulted that this solution has a cost per kWh that is much higher than that of the repowered steam plants and the new combined cycle.

Optimization of Operating Conditions and Compressor Cleaning Time Intervals of Combined Cycles in a Liberalized Market

2003 ◽  
Author(s):  
Paolo Silva ◽  
Stefano Campanari ◽  
Ennio Macchi
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Oil And Gas ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Time Variability ◽  
Primary Role ◽  
Steam Power ◽  
Combined Cycle Power Plant ◽  
Power Stations

The paper addresses the optimization of the managing strategy of a combined cycle power plant in a liberalized market characterized by great time variability of the electricity sale price. Besides electric tariffs, a variety of other factors affect the selection of the plant operating mode, such as environmental conditions, O&M costs, range of plant output regulation capability, performance deterioration of the components and compressor fouling rate. All calculations refer to a real combined cycle power plant owned by an Italian utility, for which are available detailed performance data, in “new and clean” conditions as well as in real operation. The optimum plant operating schedule is found with reference to three different tariff scenarios: (i) the present Italian situation, characterized by the primary role of oil and gas fired steam power stations, (ii) the Italian situation foreseen after the massive repowering program of existing steam power plants is completed, and (iii) a situation where the base-load electricity is generated by coal-fired power stations. The comparison indicates the utmost importance of the reference tariff scenario on the actual energy ad economic budget of the power station.

Eliminating Steam Blow Piping Overcleaning During Power Plant Startup

2008 ◽  
Author(s):  
Julie M. Jarvis ◽  
Allen T. Vieiria ◽  
Paul J. Babel ◽  
Paul J. Kochis
Keyword(s):  
Flow Rate ◽  
Power Plants ◽  
Dynamic Pressure ◽  
Turbine Blades ◽  
Service Condition ◽  
Complete Removal ◽  
Operating Conditions ◽  
Steam Turbines ◽  
Force Ratio ◽  
Foreign Materials

This paper investigates and justifies the use of a minimum necessary cleaning force ratio or cleaning factor for steam blows. Steam line blowing is an operational cleaning method used to clean steam piping and reheaters prior to turbine powering for steam power plants. The steam blows remove weld bead deposits, slag, debris, surface scale, and other foreign materials which could be carried into the steam turbines and damage the turbine blades during normal plant operation. Piping is blown, bypassing the turbine, with sufficient boiler pressure to ensure the dynamic pressure throughout the piping is greater than would be experienced during all plant operating conditions. By providing flow rates corresponding to the maximum service condition for any given section of piping, there will be sufficient kinetic energy to ensure complete removal of any impurities from the pipe. Historically, the required steam blow pressures are calculated to achieve a cleaning force ratio of 1.2. Cleaning Force Ratio (CFR) or Cleaning Factor (CF) is an industry-accepted factor that quantifies the ratio of required dynamic pressure for cleaning to maximum dynamic pressure experienced during system operation. For CFRs, the turbine vendors tend to have guidelines or ranges rather than definitive acceptance criteria. It is usually left up to the commissioning engineer, the Project Startup Manager and Owner to determine what is necessary for final acceptance. It is desirable to reduce the required minimum blowout pressure and flow rate to facilitate plant startup. By reducing the required minimum blowout pressure and flow rate, permanent plant equipment and temporary steam blow piping wear can be reduced and over cleaning avoided. Further, time between steam blows can be reduced. This paper examines the CFR guidelines for various turbine vendors and justifies reducing the CFR from 1.2 to 1.0. Advantages of the use of a minimum necessary CFR include reduced required steam blow pressures which result in safer steam blows, and less expensive temporary steam blow piping. Use of a minimum necessary CFR will still maintain the effectiveness of the steam blow.

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