Process Plant Application of an Aircraft-Type Gas Turbine

Author(s):  
H. B. Yancy

The installation to be discussed in this paper was one of the first gas generator, power turbine, centrifugal compressor design combinations to be put in ground (as opposed to airplane) power applications. As a consequence the control systems, waste heat boiler installation and other parts of the facility proved to be other than adequate for continuous duty industrial plant use and as such, has gone through a subsequent development period to overcome the many problems that were encountered. This should be kept in mind as one reads the article. The present-day industrial gas generator units incorporate simplified and reliable control systems and other successful features as a result of this earlier experimental and prototype installation. Revisions to the Phillips Petroleum Company Dumas Helium Plant Pratt Whitney GG3C gas generator and related equipment have greatly increased onstream capabilities. Replacement of unreliable controls and electrical relays has decreased unwarranted shutdowns from 80 hr in 1963 to 8 hr in 1967. Improvements in lubricating oil have increased the time between oil changes from 300 to 3000 hr. Design changes in bearings, exhaust hood, and the lubricating oil system have increased the gas generator’s reliability. The Cooper-Bessemer RT-48 free power turbine has operated maintenance-free since startup. Cooper-Bessemer’s latest design has solved the reaction turbine hood stress cracking problem. Use of this type facility in helium plant service offers advantages, but lack of flexibility has caused a considerable amount of product loss at Dumas Helium Plant.

1970 ◽  
Author(s):  
D. A. Prue ◽  
T. L. Soule

The next generation of free-turbine engines in the 2 to 5-lb/sec airflow class will undergo vast improvements in performance and efficiency. The improvements will be achieved concurrent with overall reductions in size and weight. Effort is required at optimization and miniaturization of the engine control system to keep pace with these improvements. This paper describes a conceptual design of an advanced engine control system for this class of engine. It provides gas generator and power turbine control with torque, temperature, load sharing and overspeed limiting functions. The control system was concepted to accommodate, with minimum hardware changes, such variants as regenerative cycle and/or variable power turbine geometry. In addition, considerations for closed and open loop modes of control and fluidic, electronic and hydromechanical technologies were studied to best meet a defined specification and a weighted set of evaluation criteria.


2000 ◽  
Vol 122 (2) ◽  
pp. 326-329 ◽  
Author(s):  
Mark Zarzour ◽  
John Vance

Metal mesh is a commercially available material used in many applications including seals, heat shields, filters, gaskets, aircraft engine mounts, and vibration absorbers. This material has been tested by the authors as a bearing damper in a rotordynamic test rig. The test facility was originally used to support the design of a turboprop engine, developing squirrel cages and squeeze film dampers for both the gas generator and power turbine rotors. To design the metal mesh damper, static stiffness and dynamic rap test measurements were first made on metal mesh samples in a specially designed nonrotating test fixture. These property tests were performed on samples of various densities and press fits. One sample was also tested in an Instron machine as an ancillary and redundant way to determine the stiffness. Using the stiffness test results and equations derived by a previous investigator, a spreadsheet program was written and used to size metal mesh donuts that have the radial stiffness value required to replace the squirrel cage in the power turbine. The squirrel cage and squeeze film bearing damper developed for the power turbine rotor was then replaced by a metal mesh donut sized by the computer code. Coast down tests were conducted through the first critical speed of the power turbine. The results of the metal mesh tests are compared with those obtained from previous testing with the squeeze film damper and show that the metal mesh damper has the same damping as the squeeze film at room temperature but does not lose its damping at elevated temperatures up to 103°C. Experiments were run under several different conditions, including balanced rotor, unbalanced rotor, heated metal mesh, and wet (with oil) metal mesh. The creep, or sag, of the metal mesh supporting the rotor weight was also measured over a period of several weeks and found to be very small. Based on these tests, metal mesh dampers appear to be a viable and attractive substitute for squeeze film dampers in gas turbine engines. The advantages shown by these tests include less variation of damping with temperature, ability to handle large rotor unbalance, and the ability (if required) to operate effectively in an oil free environment. Additional testing is required to determine the endurance properties, the effect of high impact or maneuver loads, and the ability to sustain blade loss loads (which squeeze films cannot handle). [S0742-4795(00)01002-4]


2021 ◽  
Vol 261 ◽  
pp. 01047
Author(s):  
Fengchang Sun ◽  
Shiyue Li ◽  
Zhonghua Bai ◽  
Changhai Miao ◽  
Xiaochuan Deng ◽  
...  

In order to improve the utilization rate of industrial waste heat and improve the fine design level of waste heat power station, this paper constructs the mathematical model of waste heat boiler and steam turbine, and puts forward the optimization design method of thermal system of waste heat power generation project. By using typical cases, it is proved that there is the optimal design pressure of HRSG, which makes the power generation of the system maximum, and provides a method to improve the power generation of HRSG.


Author(s):  
Mark Zarzour ◽  
John Vance

Metal mesh is a commercially available material used in many applications including seals, heat shields, filters, gaskets, aircraft engine mounts, and vibration absorbers. This material has been tested by the authors as a bearing damper in a rotordynamic test rig. The test facility was originally used to support the design of a turboprop engine, developing squirrel cages and squeeze film dampers for both the gas generator and power turbine rotors. To design the metal mesh damper, static stiffness and dynamic rap test measurements were first made on metal mesh samples in a specially designed nonrotating test fixture. These property tests were performed on samples of various densities and press fits. One sample was also tested in an Instron machine as an ancillary and redundant way to determine the stiffness. Using the stiffness test results and equations derived by a previous investigator, a spreadsheet program was written and used to size metal mesh donuts that have the radial stiffness value required to replace the squirrel cage in the power turbine. The squirrel cage and squeeze film bearing damper developed for the power turbine rotor was then replaced by a metal mesh donut sized by the computer code. Coast down tests were conducted through the first critical speed of the power turbine. The results of the metal mesh tests are compared with those obtained from previous testing with the squeeze film damper and Show that the metal mesh damper has the same damping as the squeeze film at room temperature but does not lose its damping at elevated temperatures up to 103 °C. Experiments were run under several different conditions, including balanced rotor, unbalanced rotor, heated metal mesh, and wet (with oil) metal mesh. The creep, or sag, of the metal mesh supporting the rotor weight was also measured over a period of several weeks and found to be very small. Based on these tests, metal mesh dampers appear to be a viable and attractive substitute for squeeze film dampers in gas turbine engines. The advantages shown by these tests include less variation of damping with temperature, ability to handle large rotor unbalance, and the ability (if required) to operate effectively in an oil free environment. Additional testing is required to determine the endurance properties, the effect of high impact or maneuver loads, and the ability to sustain blade loss loads (which squeeze films cannot handle).


2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Huairong Chen ◽  
Xi Wang ◽  
Meiyin Zhu ◽  
Nannan Gu ◽  
Shubo Yang

Abstract This paper proposes a systematic approach to design control laws for a turboprop engine. The proposed approach includes interactions decoupling and control laws design based on linear matrix inequality (LMI). First, since the main objective of the turboprop engine control system is to ensure propeller-absorbed power at a constant propeller speed, the linear model of a turboprop engine can be linearized into a two-input two-output (TITO) plants, and there exist the interactions between two control loops. Because inverted decoupling can well retain the dynamic characteristics of the original system, it is used to decouple the interactions so that the TITO plant can be divided into two single-input single-output plants, that is, gas-generator shaft speed is controlled by fuel flowrate and power turbine shaft speed is controlled by blade angle. Then, the control laws are designed separately for each control loop by solving the LMI group derived from static output feedback (SOF) and regional pole placement. Finally, the proposed approach is implemented on a two-spool turboprop engine (TSTPE) integrated model. The simulation results show that there exist strong interactions between two control loops of TSTPE, applying inverted decoupling to decouple these interactions is effective, and the gas-generator shaft speed and the power turbine speed can track their commands with appropriate performance by controlling the fuel flowrate and blade angle under the action of the designed control laws and inverted decoupling.


Author(s):  
Wilson R. Taylor ◽  
Keith Wheless ◽  
Lee G. Gray

A Jet Fuel Starter (JFS) is used to start the F100 main propulsion engines for the F-15 fighter aircraft. The JFS is a dual rotor machine which consists of a gas generator spool and a power turbine spool. The gas generator turbine wheel was designed to be contained within the turbine case in the event of a JFS overspeed. This is done by the inclusion of a containment ring in the turbine case. The initial power turbine wheel design was not able to be contained by its turbine case. A design decision was made to make this wheel frangible, that is, in an overspeed condition the wheel would break into small pieces which could be contained by the existing turbine case. An alternative design solution is proposed in this paper and an analytical proof-of-concept is presented.


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