Online compressor washing: A numerical survey of influencing parameters

2005 ◽  
Vol 219 (1) ◽  
pp. 13-23 ◽  
Author(s):  
F C Mund ◽  
P Pilidis
Keyword(s):  
Gas Turbine ◽  
Mass Flow ◽  
Power Plants ◽  
Fluid Distribution ◽  
Injection Velocity ◽  
Turbine Engine ◽  
Compressor Inlet ◽  
Droplet Sizes ◽  
Influencing Parameters ◽  
Heavy Duty Gas Turbine

Online compressor washing is an advanced method to recover power losses caused by compressor blade fouling without incurring the availability penalty of having to shut down the gas turbine engine. Liquid is sprayed into the compressor at full or near full load to wash off particulates accumulated on the compressor surfaces. In particular, the cleaning of the first stage is vital to reinstate the mass flow of the engine, and a uniform fluid distribution is desirable in order to cover the full annulus. To achieve this, washing systems are generally developed empirically. Owing to the variety of intake duct geometries and gas turbine engines, the design of washing systems is generally related to individual power plants. To illustrate the trends of the main influencing parameters, a numerical investigation has been undertaken, based on an application case of a washing system installed in a heavy-duty gas turbine. The parameters studied using computational fluid dynamics (CFD) were airflow reduction, injection location and direction, droplet mass, and injection velocity. The effectiveness of the washing system was evaluated from the fluid distribution at the compressor inlet plane. It has been shown that, depending on the spray nozzle location, different optimum droplet sizes and injection velocities are required. Consequently, the application of different nozzle types is advisable. The operating condition of the engine has a significant effect on the fluid distribution at the compressor inlet and therefore changes in engine mass flow have to be considered when deciding on a washing scheme.

Effects of Spray Parameters and Operating Conditions on an Industrial Gas Turbine Washing System

2004 ◽  
Author(s):  
Friederike C. Mund ◽  
Pericles Pilidis
Keyword(s):  
Gas Turbine ◽  
Droplet Size ◽  
Mass Flow ◽  
Gas Turbines ◽  
Numerical Study ◽  
Operating Conditions ◽  
Injection Velocity ◽  
Spray Parameters ◽  
Compressor Inlet ◽  
Spray Distribution

Gas turbines for power generation are exposed to a variety of ambient conditions and are therefore bound to breathe contaminated airflow, thus degrading the engines internal gas path. In particular, accumulated debris on the compressor blades reduces engine efficiency. To recover this performance loss, online compressor washes may be performed. Cleaning fluid is injected through the nozzles upstream of the compressor to wash off the debris from the blades. This paper presents a numerical study of a generic compressor washing system based on an application case for a heavy duty gas turbine power plant. The inlet duct of the engine was modeled and droplet trajectories were calculated. Different spray patterns including single jet and full cone have been investigated for different ranges of injection velocity and droplet size. The spray angle was evaluated experimentally and was used to model the full cone spray pattern. The boundary conditions for the airflow were iterated with a performance simulation tool to match pressure loss and mass flow. To investigate the effect of different operating conditions on the airflow and spray distribution, an installation scenario of the engine at altitude on a hot summer day was modeled. The scenario was based on a review of plant installations and local meteorological conditions. Fluid concentration plots at the compressor inlet plane were evaluated for the different computational cases. Generally with lower injection momentum, the water droplets were significantly deflected by the main airflow. Higher injection velocity and droplet size reduced the effect of the main airflow. Different operating conditions and the significant change of air mass flow affected the spray distribution of the washing system at the compressor inlet. This can be compensated by adjusting the injection angles.

scholarly journals Thermodynamic Analysis of Different Configurations of Combined Cycle Power Plants

2015 ◽  
Vol 5 (2) ◽  
pp. 89
Author(s):  
Munzer S. Y. Ebaid ◽  
Qusai Z. Al-hamdan
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Maximum Efficiency ◽  
Specific Work ◽  
Slight Effect ◽  
Turbine Engine ◽  
Gas Turbine Cycle ◽  
Cycle Efficiency

<p class="1Body">Several modifications have been made to the simple gas turbine cycle in order to increase its thermal efficiency but within the thermal and mechanical stress constrain, the efficiency still ranges between 38 and 42%. The concept of using combined cycle power or CPP plant would be more attractive in hot countries than the combined heat and power or CHP plant. The current work deals with the performance of different configurations of the gas turbine engine operating as a part of the combined cycle power plant. The results showed that the maximum CPP cycle efficiency would be at a point for which the gas turbine cycle would have neither its maximum efficiency nor its maximum specific work output. It has been shown that supplementary heating or gas turbine reheating would decrease the CPP cycle efficiency; hence, it could only be justified at low gas turbine inlet temperatures. Also it has been shown that although gas turbine intercooling would enhance the performance of the gas turbine cycle, it would have only a slight effect on the CPP cycle performance.</p>

scholarly journals Clear Skies Ahead

2016 ◽  
Vol 138 (06) ◽  
pp. 38-43
Author(s):  
Lee S. Langston
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Electrical Power ◽  
Vital Role ◽  
Medium Size ◽  
Steady Increase ◽  
Innovative Design ◽  
Turbine Engine ◽  
Boom And Bust

This article discusses various fields where gas turbines can play a vital role. Building engines for commercial jetliners is the largest market segment for the gas turbine industry; however, it is far from being the only one. One 2015 military gas turbine program of note was the announcement of an U.S. Air Force competition for an innovative design of a small turbine engine, suitable for a medium-size drone aircraft. The electrical power gas turbine market experienced a sharp boom and bust from 2000 to 2002 because of the deregulation of many electric utilities. Since then, however, the electric power gas turbine market has shown a steady increase, right up to present times. Coal-fired plants now supply less than 5 percent of the electrical load, having been largely replaced by new natural gas-fired gas turbine power plants. Working in tandem with renewable energy power facilities, the new fleet of gas turbines is expected to provide reliable, on-demand electrical power at a reasonable cost.

scholarly journals Comparison of Coriolis and Turbine Type Flow Meters for Fuel Measurement in Gas Turbine Testing

1993 ◽  
Author(s):  
J. D. MacLeod ◽  
W. Grabe
Keyword(s):  
Steady State ◽  
Gas Turbine ◽  
Mass Flow ◽  
Gas Turbines ◽  
Gas Turbine Engine ◽  
Turbine Engine ◽  
Turbine Flowmeter ◽  
Turbine Performance ◽  
Coriolis Flowmeter ◽  
Project Objectives

The Machinery and Engine Technology (MET) Program of the National Research Council of Canada (NRCC) has established a program for the evaluation of sensors to measure gas turbine engine performance accurately. The precise measurement of fuel flow is an essential part of steady-state gas turbine performance assessment. Prompted by an international engine testing and information exchange program, and a mandate to improve all aspects of gas turbine performance evaluation, the MET Laboratory has critically examined two types of fuel flowmeters, Coriolis and turbine. The two flowmeter types are different in that the Coriolis flowmeter measures mass flow directly, while the turbine flowmeter measures volumetric flow, which must be converted to mass flow for conventional performance analysis. The direct measurement of mass flow, using a Coriolis flowmeter, has many advantages in field testing of gas turbines, because it reduces the risk of errors resulting from the conversion process. Turbine flowmeters, on the other hand, have been regarded as an industry standard because they are compact, rugged, reliable, and relatively inexpensive. This paper describes the project objectives, the experimental installation, and the results of the comparison of the Coriolis and turbine type flowmeters in steady-state performance testing. Discussed are variations between the two types of flowmeters due to fuel characteristics, fuel handling equipment, acoustic and vibration interference and installation effects. Also included in this paper are estimations of measurement uncertainties for both types of flowmeters. Results indicate that the agreement between Coriolis and turbine type flowmeters is good over the entire steady-state operating range of a typical gas turbine engine. In some cases the repeatability of the Coriolis flowmeter is better than the manufacturers specification. Even a significant variation in fuel density (10%), and viscosity (300%), did not appear to compromise the ability of the Coriolis flowmeter to match the performance of the turbine flowmeter.

Development of Dry Low-NOx Combustor for 300 kW Class Gas Turbine Applied to Co-Generation Systems

2001 ◽  
Author(s):  
Yoichiro Ohkubo ◽  
Osamu Azegami ◽  
Hiroshi Sato ◽  
Yoshinori Idota ◽  
Shinichiro Higuchi
Keyword(s):  
Gas Turbine ◽  
Output Power ◽  
Combustion Efficiency ◽  
Gas Generator ◽  
Turbine Engine ◽  
Partial Load ◽  
Wide Range ◽  
Compressor Inlet ◽  
Endurance Testing ◽  
Turbine Speed

A 300 kWe class gas turbine which has a two-shaft and simple-cycle has been developed to apply to co-generation systems. The gas turbine engine is operated in the range of about 30% partial load to 100% load. The gas turbine combustor requires a wide range of stable operations and low NOx characteristics. A double staged lean premixed combustor, which has a primary combustion duct made of Si3N4 ceramics, was developed to meet NOx regulations of less than 80 ppm (corrected at 0% oxygen). The gas turbine with the combustor has demonstrated superior low-emission performance of around 40 ppm (corrected at 0% oxygen) of NOx, and more than 99.5% of combustion efficiency between 30% and 100% of engine load. Endurance testing has demonstrated stable high combustion performance over 3,000 hours in spite of a wide compressor inlet air temperature (CIT) range of 5 to 35 degree C.. While increasing the gas generator turbine speed, the flow rate of primary fuel was controlled to hold a constant equivalence ratio of around 0.5 in the CIT range of more than 15 C. The output power was also decreased while increasing the CIT, in order to keep a constant temperature at the turbine inlet. The NOx decreases in the CIT range of more than 15 C. On the other hand, the NOx increases in the CIT range of less than 15 C when the output power was kept a constant maximum power. As a result, NOx emission has a peak value of about 40 ppm at 15 C.

scholarly journals A Small Scale Biomass Fueled Gas Turbine Engine

1998 ◽  
Author(s):  
Joe D. Craig ◽  
Carol R. Purvis
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Small Scale ◽  
Brayton Cycle ◽  
Prime Mover ◽  
Turbine Engine ◽  
Rice Hulls ◽  
Turbine Component ◽  
The Cost ◽  
New Generation

A new generation of small scale (less than 20 MWe) biomass fueled, power plants are being developed based on a gas turbine (Brayton cycle) prime mover. These power plants are expected to increase the efficiency and lower the cost of generating power from fuels such as wood. The new power plants are also expected to economically utilize annual plant growth materials (such as rice hulls, cotton gin trash, nut shells, and various straws, grasses, and animal manures) that are not normally considered as fuel for power plants. This paper summarizes the new power generation concept with emphasis on the engineering challenges presented by the gas turbine component.

Design, Fabrication, and Testing of a Semi-Closed Cycle Gas Turbine Engine

2001 ◽  
Author(s):  
C. Rodgers
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Low Pressure ◽  
Exhaust Gas ◽  
Closed Cycle ◽  
Demonstration Program ◽  
Turbine Engine ◽  
Compressor Inlet ◽  
Gas Recirculation ◽  
Engine Development

A small semi-closed gas turbine was designed, fabricated, and tested to demonstrate the cycle the cycle feasibility with exhaust gas recirculation. The demonstrator unit comprised a low pressure spool compressor and turbine supercharging a high pressure spool compressor and turbine, whose exhaust passed through a recuperator, and was subsequently split, one half being recirculated to the high pressure spool compressor inlet via an intercooler, and the remaining half expanded across the low pressure spool turbine. The design and fabrication phases proceeded on schedule but commencement of engine development testing encountered mechanical difficulties. These were eventually resolved and shakedown testing of the demonstrator accomplished prior to final contractual delivery. The demonstration program was funded under a NASA LeRc contract NAS3-27396.

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