Experimental and Numerical Investigation of a Large Cylindrical Oil-Fired Combustor

The present work presents measurements of velocity, temperature and heat transfer rates carried out on a segmented water-cooled cylindrical oil-fired flame tube typical of a 0.56 kg/s packaged fire-tube steam boiler. A prediction procedure, that solves the conservation equations of the various entities, was successfully used to produce computed velocities, temperatures and heat flux distributions. A two-equation turbulence model, a combustion model and a discrete ordinate radiation model were used to approximate the various characteristics of the flow. The combustion model solved the Eulerian equations of the gas phase, and the Lagrangian equations of the droplet motion, heating, evaporation and combustion.

Gas Turbine Installation and Foundation Repair With Epoxy Resins

Epoxy resins are not just replacements for concrete and cement grouts, they offer the opportunity for completely new foundation/gas turbine interface designs. As a substitute for steel chocks, epoxy resin ones give perfect fit, high holding force and good thermal insulation, while eliminating the need for soleplates or rails.

Control Aspects of a Compressor Station for Gas Lift

The type and characteristics of the control system to be used for a centrifugal compressor station depend on several factors such as the compressor driver, process requirements, and the conditions under which the compressor will be operated. Designing a compressor control system for gas lift applications present different types of problems than those of conventional pipeline applications. This paper describes the control philosophy of a compressor station used for lifting water in a closed-rotative gas lift installation in Bu Hasa field, Abu Dhabi.

Modelling of Soot Formation in Spray Combustors

A model for the prediction of the distribution of soot concentration in spray combustors is presented. Both gas-phase and liquid-phase soot formation have been considered. The methods have been developed within the constraints on detailed combustion modelling for practical application. Some predictions are assessed by comparison with published experimental data. It is concluded that predictions of the same quality as those of gaseous-fuelled combustors may be obtained neglecting liquid-phase soot formation in case of light fuels.

Drop Size Measurements in Evaporating Realistic Sprays of Emulsified and Neat Fuels

A comparative study has been performed of the drop-size distribution of sprays of emulsified and neat distillate-type aviation fuels at elevated temperatures (308K to 700K) and pressures (101 kPa to 586 kPa). All drop-size data were obtained with a Malvern Model 2200 Particle Sizer based on the forward angle diffraction pattern produced by the drops when illuminated by a collimated HeNe laser beam. Fuels included a standard multicomponent jet fuel, Jet-A, and a single component fuel, hexadecane, in both neat form and emulsified with 20 percent (by vol.) water and 2 percent (by vol.) surfactant. The initial breakup and atomization of a neat and emulsified fuel were quite similar at all conditions, and the evaporation rates appeared similar at various temperatures for pressures at or below about 300 kPa. At higher pressures with elevated temperatures the emulsified fuels of both types produce drops of significantly smaller Sauter mean diameter than the neat fuels as distance from the nozzle increases. These results are consistent with the microexplosion hypothesis, but there could also be alternative explanations. A detailed computer model which predicts heat up rates, steady state drop temperatures, evaporation rates, and drop trajectories has been used to help interpret the results. An additional point which has been observed is that the initial Sauter mean diameter produced with constant differential nozzle pressure is dependent on the air pressure with an exponent of about −0.4, i.e., SMD ∼ Pair−0.4. Some recent correlations often quoted omit the pressure (density) of air term.

Development Status of Coal-Fired Gas Heaters for Brayton-Cycle Cogeneration Systems

Under contract from the Department of Energy, Rocketdyne is developing the technology of coal-fired gas heaters for utilization in Brayton-cycle cogeneration systems. The program encompasses both atmospheric fluidized bed and pulverized coal combustion systems; and it is directed toward the development of gas heater systems capable of delivering high pressure air or helium at 1550 F, when employing metallic heat exchangers, and 1750 F, when employing ceramic heat exchangers. This paper reports on the development status of the program, with discussions of the completed “screening” corrosion/erosion tests of candidate heat exchanger materials, a description and summary of the operating experience with the 6- by 6-foot AFB test facility and a projection of the potential for relatively near term commercialization of such heater systems.

Investigation of Fixed-Rake Sampling System for the Assessment of Emission Characteristics of Gas Turbine Engines

The regulations proposed by the US Environmental Protection Agency to limit the quantity of pollutant gases emitted by aircraft engines allow the exhaust of engines submitted for compliance testing to be sampled by a fixed-multipoint rake. However, the onus is placed on the manufacturer to prove the representativeness of the samples taken in this relatively cheap fashion. To illustrate best possible accuracies, the exhaust of an M45H civil turbofan engine has hen extensively sampled and a computer program has been used to select the optimum configuration of a cruciform rake. The program demanded excellent agreement between the sampling methods and this proved to be the case in actual tests. However, the program also indicates that the errors of a simply designed rake giving area-weighted samples would also be less than 10%. Sampling in the FAA diamond pattern would give rise to a 20% error in CO emissions.

State-of-the-Art Review of Closed Cycle Gas Turbines Burning Dirty Fuels

The Closed Cycle Gas Turbine (CCGT) offers potential savings in operating costs due to high system efficiency and the ability to direct fire coal. However, for the full potential of CCGT to be realized, more competitive cost information must be generated, correlated, and compared with conventional steam power systems. Current development programs are intended to resolve many of the remaining uncertainties in design, performance, and cost by detailed examination and testing of critical components of CCGT coal-fired power systems. This paper reviews current technology developments and economic considerations of the closed cycle gas turbine burning dirty fuels versus conventional steam power systems.

Turbine Deposition Evaluations Using Simplified Tests

Relatively simple and inexpensive tests (compared to cascade and turbine tests) have been utilized in deposition evaluations for alternate ash-bearing turbine fuels. These tests use simple cylindrical specimen geometries and test equipment which have adequately simulated turbine corrosion environments in the past. However, deposition rates on a cylindrical test specimen are not the same as deposition rates for turbine airfoils due to geometry differences. An approach is here described for extrapolating measured deposit buildup rates on cylindrical test specimens to project deposit buildup rates on turbine airfoils and turbine maintenance intervals for deposit removal. Deposition environments are identified for which the data extrapolation approach applies. This approach has provided reasonable deposition assessments for turbine operation with residual oil and coal-derived liquid fuels. Using data from residual oil tests representing current turbine operating conditions, maintenance intervals to remove deposits have been predicted which are in agreement with field experience.

Operating Experience With a Waste Heat Recovery System Installed on a Pipeline Compressor Station

Construction of the Borsig waste heat recovery system at NOVA’s Clearwater Compressor Station is now complete. Initial operation of the system has been very encouraging. This paper is an update on an earlier paper entitled “Pipeline Compressor Station with Waste Heat Recovery” by G. M. Holldorff, A. R. Hladun and S. A. Dunn. The process cycle including main components and control functions will be reviewed and their performance evaluated. Operating experience to date is also presented. In emphasizing safety, NOVA has instituted unique operating and maintenance procedures to this system. These procedures are also outlined.