BULLETIN ARCHIVE   

BULLETIN # PB-1002 : W501AA Low NOx Technology (LNT) Combustors

Description
Power Tech Associates, Inc. (PTA) has proven technology (patented) and W501AA combustor hardware capable of achieving 35 to 40% reduction in NOx emissions as compared to that achieved with standard combustors.  The combustors are brazed and thermal barrier coated for high durability. They are interchangeable (in sets) with standard combustors. 

The W501AA LNT combustors were tested at Jersey Central Power & Light’s Sayreville station with results as shown in Table 1.

Table 1   W501AA LNT Test Results
Base Load

*Dry, ISO, 15% O₂
**Reduction from standard combustor value
***Dry, 15% O₂

PTA can provide W501AA LNT combustors completely new or re-manufactured using necks and domes from existing standard combustors.

Benefits
The use of LNT combustors will provide a 35 to 40% reduction in NOx emissions through a simple change-out of combustors.  No other changes in the combustor system are required to achieve the stated NOx reduction.  The LNT combustors are compatible with water injection.  Use of LNT combustors in conjunction with water injection will reduce the amount of water 35 to 40% for a given NOx reduction as compared to that required with standard combustors.  The LNT combustors work with both gas and liquid fuels.

BULLETIN # PB-1003 : Frame 5N Low NOx Technology (LNT) Combustors

Description
Power Tech Associates, Inc. (PTA) has proven technology (patented) and Frame 5N combustor hardware capable of achieving 20 to 25% reduction in NOx emissions as compared to that achieved with standard combustors.  The combustors are interchangeable (in sets) with standard combustors.

The Frame 5N LNT combustors were tested at Jersey Central Power & Light’s Glen Gardner station with results as shown in Table 1.

Table :  Frame 5N LNT Test Results
Base Load

*Dry, ISO, 15% O₂
**Reduction from standard combustor value
***Dry, 15% O₂

A later version of the Frame 5N LNT combustor has been designed, but not tested, that is expected to achieve 35 to 40% NOx reduction.

Benefits
The use of LNT combustors will provide up to 40% reduction in NOx emissions through a simple change-out of combustors.  No other changes in the combustor system are required to achieve the stated NOx reduction.  The LNT combustors are compatible with water injection.  Use of LNT combustors in conjunction with water injection will reduce the amount of water up to 40% for a given NOx reduction as compared to that required with standard combustors.  The LNT combustors work with both gas and liquid fuels.

BULLETIN # PB-1004 : Single Point Emissions Measurement (SPEM)

Background
Power Tech Associates, Inc. (PTA) has developed a Single Point Emissions Measurement (SPEM) method for field-testing the emissions performance of improved combustors that represents significant advantages as compared to the conventional method of testing complete sets of combustors.  Use of the SPEM technology permits alteration of only one combustor instead of a full set (10 to 18) to provide a provisional evaluation of a NOx target, before proceeding to final proof test involving a full set of combustors.  The SPEM technology is applicable to any engine having multiple combustors and to sections of annular combustors.

Benefits
The advantages of SPEM are as follows:

1)      Only one new or modified combustor (instead of a complete set) is required for testing each combustor modification.  This represents a significant savings in the cost of the test combustors.

2)      The baseline test can be run simultaneously with the test of a modified combustor.  This represents a significant savings in time and the cost of testing.  It also rules out any potential errors due to differences in test conditions from the baseline test conditions to the modified combustor test conditions.

3)      For each test of a modified combustor, only the single test combustor is required to be changed out instead of the complete set as is done with the conventional method.  This represents a significant savings in time and labor expenditures.

4)      The SPEM methodology can be adapted for semi-continuous measurements in situations where a full CEMS is unnecessary, e.g. measuring NOx.

Licensed use of SPEM
The SPEM technology is patented by PTA.  PTA is prepared to provide licensed use of SPEM, technical support, and on-site installation, application and analysis.

BULLETIN # PB-1005 : Gas-only Fuel Nozzle

Background
Power Tech Associates, Inc. (PTA) has developed a simplified gas-only fuel nozzle for W501 and W251gas turbines.  This fuel nozzle, when used in conjunction with water injection, will reduce the amount of water required for a given amount of NOx reduction up to 40% as compared to standard water injection techniques.  In addition, the CO level is significantly lower than that achieved with water injection using the standard fuel nozzle.

Benefits
The benefits of the gas-only fuel nozzle are as follows:

1)      The gas-only fuel nozzle is a simplified and inexpensive design.

2)      For gas-only combustion turbines that utilize water injection for NOx control, the PTA fuel nozzle will reduce the amount of water consumption up to 40% as compared to standard water injection techniques.  In addition to the savings in water consumption, the reduced water usage will result in longer life of the hot parts due to less wear and tear associated with water injection.

3)      For gas-only combustion turbines that utilize water injection for NOx control, the PTA fuel nozzle will significantly reduce the amount of CO for a given amount of NOx reduction as compared to that achieved with standard water injection techniques.

BULLETIN # PB-1006 : Low NOx Technology (LNT) Combustors for Aeroderivative Engines

Description
Power Tech Associates, Inc. (PTA) has proven technology (patented) and combustor hardware for industrial gas turbines capable of achieving 35 to 40% reduction in NOx emissions as compared to that achieved with standard combustors.  To date, this technology has been developed for the W251AA, W501AA, and Frame 5N engines.  The combustors are brazed and thermal barrier coated for high durability. They are interchangeable (in sets) with standard combustors.

The same principles that were used for development of the above mentioned industrial gas turbines are applicable to aeroderivative diffusion-flame combustors such as those used in the FT-4, LM2500, and Avon engines.  PTA is prepared to participate with users to develop low NOx combustors for those engines.  PTA will provide the development and test plan, engineering, combustor modifications, and all data acquisition equipment.  The customer will provide access to a test engine, combustor change-outs, and operation of the test unit during the trials.  Please contact PTA for further details.

Benefits
The use of LNT combustors will provide a 35 to 40% reduction in NOx emissions through a simple change-out of combustors.  No other changes in the combustor system are required to achieve the stated NOx reduction.  The LNT combustors are compatible with water injection.  Use of LNT combustors in conjunction with water injection will reduce the amount of water 35 to 40% for a given NOx reduction as compared to that required with standard combustors.  The LNT combustors work with both gas and liquid fuels.

BULLETIN # PB-1007 : CAES Combustion System Components

Description
Power Tech Associates, Inc. (PTA) has re-designed and provided the following combustion system components for the Alabama Electric Cooperative (AEC) Compressed Air Energy Storage (CAES) plant in McIntosh Alabama.

Low Pressure (LP) Expander

• Combustors
• Fuel Nozzles
• Torch Igniters

High Pressure (HP) Expander

• Combustors
• Fuel Nozzles
• Torch Igniters

The designs of these combustor systems are unique with respect to the following:

1)      The HP expander combustor operates at a pressure level of 44 atmospheres which is considerably higher than that experienced in conventional gas turbines.

2)      The LP combustor operates with exhaust (vitiated) air from the HP combustor that has had partial oxygen removal due to combustion in the HP expander.

Benefits
PTA is well equipped to design combustor systems of all types, including those with non-standard features as described above.

BULLETIN # PB-1008 : CHAT and HAT Cycles

Description
Power Tech Associates, Inc. (PTA) has developed preliminary conceptual combustor designs suitable for the Cascaded Humidified Advanced Turbine (CHAT) and Humidified Air Turbine (HAT) cycles.

Both cycles involve the combustion of air that has been humidified with up to 15% water vapor.  The high water concentration in the combustor inlet flow lowers the stoichiometric flame temperature and therefore the chemical reaction rate between fuel and oxygen.  This tends to increase the size of the combustor required for stable operation and high combustion efficiency.

In addition, the CHAT cycle involves both high pressure (HP) and low pressure (LP) combustors.

The designs of the HP and LP combustors are unique with respect to the following:

1)      The HP expander combustor operates at a pressure level of 56 atmospheres which is considerably higher than that experienced in conventional gas turbines.

2)      The LP combustor operates with exhaust (vitiated) air from the HP combustor that has had partial oxygen removal due to combustion in the HP expander.

Benefits
PTA is well equipped to design combustor systems of all types, including those with non-standard features as described above.

BULLETIN # PB-1009 : Failure Analysis

Description
Power Tech Associates, Inc. (PTA) has numerous associates with many years of experience in the areas of gas turbine design, manufacturing, field operation and trouble shooting.  This experience is utilized in analyzing failures in gas turbine engines, determining the root cause of failure, and making recommendations for corrective action.  Areas of expertise include, but are not limited to, the following:

·        Combustion systems

·        Fuel systems

·        Rotors

·        Blades and vanes

·        Compressors

·        Generators

Benefits
PTA is well equipped to provide the above described engineering services on a timely and cost effective basis.

BULLETIN # PB-1010 :  Engineering Support for Operating Engines

Description
Power Tech Associates, Inc. (PTA) has numerous associates with many years of experience in providing engineering support for operating engines.  Areas of expertise include, but are not limited to, the following:

·        Mechanical design and analysis of turbine components and systems: vibration, stress, thermal

·        Aero/thermo heat transfer design

·        Engine and cycle performance

·        Fuels and combustion design

·        Emissions predictions and control

·        Power Augmentation: water/steam injection

·        Plant performance and economics

·        Plant maintenance and practices

·        Operator training programs

·        Control system design and trouble shooting

·        Instrumentation of hot parts: temperature, vibration, strain

·        Corrosion control and fuel specifications

·        Corrosion evaluations and coating recommendations

·        Metallurgical failure analysis

·        Hot parts reconditioning recommendations and remaining life assessment

·        Mechanical, electrical, and control expertise for installation, service, problem solving and startup

·        Electrical system trouble shooting & problem solving

·        Test program design, planning and implementation

Benefits
PTA is well equipped to provide the above described engineering services on a timely and cost effective basis.

BULLETIN # PB-1011 : Engineering Outage Support

Description
Power Tech Associates, Inc. (PTA) has associates with many years of experience in providing outage support for industrial and aeroderivative gas turbine engine users.  Areas of expertise include, but are not limited to, the following:

·        Provide on-site assistance and in-shop inspection for gas turbine overhauls and inspections

·        Oversee disassembly and assembly procedures

·        Provide metallurgical failure analysis

·        Review vendor qualification

·        Provide oversight of vendor procedures

·        Evaluate gas turbine rotor repair shops

Benefits
PTA is well equipped to provide the above described engineering services on a timely and cost effective basis.

BULLETIN # PB-1012 : Feasibility of Novel Plant Schemes

Description
Power Tech Associates, Inc. (PTA) has numerous associates with many years of experience in evaluating the feasibility of novel plant schemes.  Examples of work performed include, but are not limited to, evaluation of the following:

·        Air turbine systems using renewable and waste energy sources

·        New water and steam injection schemes

·        Inlet cooling and over-spray schemes

·        Novel gas turbine cycles

·        Using waste fuels in gas turbines

·        Novel application of exhaust cleanup systems

·        Upgrade of combustion and fuel injection system

Benefits
PTA is well equipped to provide the above described engineering services on a timely and cost effective basis.

BULLETIN # PB-1013 : Dispute Resolution

Description
Power Tech Associates, Inc. (PTA) has numerous associates with many years of experience in providing expert support and witness for resolution of disputes involving gas turbine and other power pants.  Examples of work performed include, but are not limited to, the following:

·        Relationship of compressor failure to repair methods

·        Influence of rotor design and durability on availability/reliability targets

·        DLN flashback incidents

·        Turbine fouling

·        Hot corrosion effects related to turbine failures

·        Failure to implement design upgrades causing engine damage

Benefits
PTA is well equipped to provide the above described engineering services on a timely and cost effective basis.

BULLETIN # PB-1014 : Diagnostic and Condition Monitoring Instrumentation

Description
Power Tech Associates, Inc. (PTA) has a comprehensive line of specialty instrumentation for use in obtaining diagnostic information and for monitoring the condition of gas turbine engines.  Examples of instrumentation provided include, but are not limited to, the following:

·        Combustor wall temperature measurement

·        Combustor dynamic pressure measurement

·        Gas sampling from combustor

·        Transition wall temperature measurement

·        Transition vibration measurement with accelerometers

·        Transition exit gas temperature profile measurement

·        Vane temperature measurement with embedded thermocouples

In a cooperative venture with SKF Reliability Systems, PTA offers a complete combustor system monitor that includes Vibra-Meter differential pressure sensors and software by Kema.  The system enables an operator to simultaneously monitor combustion system dynamic pressure, blade path temperature, emissions, and other variables of interest; reacting to unacceptable deviations by changing operating conditions to prevent hardware damage

Benefits
The use of diagnostic and conditioning monitoring instrumentation can provide information regarding a particular problem or advance warning leading to prevention of catastrophic failures in gas turbine engines.  PTA is well equipped to provide the above described monitoring instrumentation on a timely and cost effective basis.

COPYRIGHT Power Tech Associates, Inc. 2005