Ammonia Turbine Design for Ocean Thermal Energy Conversion (OTEC) Plants

1981 ◽  
Vol 103 (2) ◽  
pp. 92-97 ◽  
Author(s):  
C. H. Kostors ◽  
S. P. Vincent
Keyword(s):  
Synchronous Generator ◽  
Cost Effective ◽  
Turbine Generator ◽  
Turbine Efficiency ◽  
Turbine Blade Design ◽  
Ocean Thermal Energy ◽  
Turbine Design ◽  
Single Flow ◽  
Hardware Designs ◽  
Percent Efficiency

During the optimization studies of a 10-MWe (net) OTEC power system the ammonia turbine design study led to selection of a four-stage, double-flow axial turbine yielding 89.6 percent efficiency at 1800 rpm. To maximize power at off-nominal conditions, variable nozzles are used for the first stage. The turbine is directly connected to a four-pole, 60-Hz synchronous generator having 97.2 percent efficiency. This study was limited to state-of-the-art hardware designs for axial- and radial-flow turbines, single- and double-flow designs, and variations in the base diameter and number of turbine stages. The gasdynamic calculation procedure and the effects of the turbine generator control scheme, turbine blade design, materials (annealed AISI Type 403 steel is chosen for the blading), and seals and bearings are addressed in this paper. The estimated mass-production cost of the turbine-generator set is approximately $150/kWe at 10-MWe (net) size in 1979 dollars. Single-flow-axial and radial-inflow turbines would have lower performance without sufficiently lower cost to be cost-effective, since each percentage point of turbine efficiency is estimated to be worth 17 to $28/kWe.

Experience in the Use of a Digital Computer for Predicting Steam-Turbine Performance

1964 ◽  
Vol 179 (1) ◽  
pp. 307-342
Author(s):  
R. U. McCrae ◽  
A. Montague ◽  
M. Douglass
Keyword(s):  
Energy Balance ◽  
Steam Turbine ◽  
Turbine Generator ◽  
Design And Optimization ◽  
Turbine Efficiency ◽  
Turbine Performance ◽  
Experienced Programmer ◽  
Turbine Design ◽  
Considerable Detail

This paper describes a number of programmes for digital computers that have been developed by the authors' firm to eliminate many of the tedious hand calculations which are encountered in the preliminary stages of steam-turbine and condenser design. By their use a considerable amount of the designers' time is saved and fatigue is reduced. These programmes also eliminate mistakes and inaccuracies which may occur in long calculations made by hand. The programmes described have been chosen as being representative of the range of programmes used in preliminary turbine design and optimization and are as follows: a programme to enable steam properties to be calculated, based on the formulae given in the Keenan and Keyes Steam Tables; a programme which can be used to determine the efficiency of small industrial turbines; a feed-heating programme which will carry out the calculations necessary to determine the preliminary energy balance for a feed-heating cycle; a detailed energy-balance programme incorporating turbine-efficiency calculations; a condenser-optimization programme for determination of the ideal parameters to be used in the design of a condenser. The programmes are arranged so that unskilled operators can run them on the computer without the help of an experienced programmer. Facilities are also made available for writing programmes in a simplified form called ‘autocode’ which can be used by an engineer after the briefest of trainings. Some programmes are described in considerable detail to assist others who may wish to write a similar programme or to compare them with programmes of their own. All these programmes have been in regular use for more than three years and have greatly enlarged the scope of investigations which may be carried out in the project stage of the design of a steam-turbine generator and associated power-station equipment.

Optimization of a Closed-Cycle OTEC System

1990 ◽  
Vol 112 (4) ◽  
pp. 247-256 ◽  
Author(s):  
Haruo Uehara ◽  
Yasuyuki Ikegami
Keyword(s):  
Heat Exchangers ◽  
Sea Water ◽  
Working Fluid ◽  
Turbine Efficiency ◽  
Thermal Energy Conversion ◽  
Calculation Results ◽  
Change Temperature ◽  
Ocean Thermal Energy ◽  
Powell Method ◽  
Method Of Steepest Descent

Optimization of an Ocean Thermal Energy Conversion (OTEC) system is carried out by the Powell Method (the method of steepest descent). The parameters in the objective function consist of the velocities of cold sea water and warm sea water passing through the heat exchangers, the phase change temperature, and turbine configuration (specific speed, specific diameter, ratio of blade to diameter). Numerical results are shown for a 100-MW OTEC plant with plate-type heat exchangers using ammonia as working fluid, and are compared with calculation results for the case when the turbine efficiency is fixed.

Standardization of Cross Flow Turbine Design for Typical Micro-Hydro Site Conditions in Pakistan

2014 ◽  
Author(s):  
J. A. Chattha ◽  
M. S. Khan ◽  
H. Iftekhar ◽  
S. Shahid
Keyword(s):  
Electrical Power ◽  
Cross Flow ◽  
Power Production ◽  
Radius Of Curvature ◽  
Manufacturing Cost ◽  
Site Conditions ◽  
Hydro Power ◽  
Turbine Efficiency ◽  
Turbine Design ◽  
Typical Site

Pakistan has a hydro potential of approximately 42,000MW; however only 7,000MW is being utilized for electrical power production [1, 2]. Out of 42,000 MW, micro hydro potential is about 1,300MW [1, 2]. For typical site conditions (available flow rate and head) in Pakistan, Cross Flow Turbines (CFTs) are best suited for medium head 5–150m [3] for micro-hydro power production. The design of CFT generally includes details of; the diameter of the CFT runner, number of blades, radius of curvature and diameter ratio. This paper discusses the design of various CFTs for typical Pakistan site conditions in order to standardize the design of CFTs based on efficiency that is best suited for a given site conditions. The turbine efficiency as a function of specific speed will provide a guide for cross flow turbine selection based on standardized turbine for manufacturing purposes. Standardization of CFT design will not only facilitate manufacturing of CFT based on the available site conditions with high turbine efficiency but also result in reduced manufacturing cost.

Steam Turbine Design Considerations for Ultrasupercritical Cycles

2010 ◽  
Author(s):  
Justin Zachary
Keyword(s):  
Power Generation ◽  
Cost Effective ◽  
Design Phase ◽  
Steam Turbines ◽  
Effective Solution ◽  
Technical Approach ◽  
Design Considerations ◽  
Balance Of Plant ◽  
Turbine Design ◽  
The Impact

The current coal-fired power generation market requires higher cycle efficiencies not only for economic reasons, but also as a means of reducing plant carbon footprint. To achieve these goals, the plant must operate at higher pressures and temperatures in the supercritical (SC) and ultrasupercritical (USC) domains. This paper describes Bechtel’s experience and challenges in regard to the conceptual design and integration of large steam turbines operating under these severe conditions. Several examples of projects are described wherein Bechtel applied this neutral but proactive technical approach in the development or design phase to achieve the best and most cost-effective solution for its customers. The topics presented also relate to steam cycle optimization in terms of plant output, steam conditions, number of reheat circuits, and type and number of heaters. The impact on balance of plant systems, including water treatment, availability, and redundancy criteria, is also addressed.

Parameter Optimization on Combined Gas Turbine-Fuel Cell Power Plants

2005 ◽  
Vol 2 (4) ◽  
pp. 268-273 ◽  
Author(s):  
Rainer Kurz
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Power Plants ◽  
Pressure Ratio ◽  
Design Parameters ◽  
Turbine Efficiency ◽  
Compressor Pressure Ratio ◽  
Turbine Design ◽  
Cycle Efficiency ◽  
Compressor Efficiency

A thermodynamic model for a gas turbine-fuel cell hybrid is created and described in the paper. The effects of gas turbine design parameters such as compressor pressure ratio, compressor efficiency, turbine efficiency, and mass flow are considered. The model allows to simulate the effects of fuel cell design parameters such as operating temperature, pressure, fuel utilization, and current density on the cycle efficiency. This paper discusses, based on a parametric study, optimum design parameters for a hybrid gas turbine. Because it is desirable to use existing gas turbine designs for the hybrids, the requirements for this hybridization are considered. Based on performance data for a typical 1600hp industrial single shaft gas turbine, a model to predict the off-design performance is developed. In the paper, two complementary studies are performed: The first study attempts to determine the range of cycle parameters that will lead to a reasonable cycle efficiency. Next, an existing gas turbine, that fits into the previously established range of parameters, will be studied in more detail. Conclusions from this paper include the feasibility of using existing gas turbine designs for the proposed cycle.

On the Design and Matching of Turbocharger Single Scroll Turbines for Pass Car Gasoline Engines

2014 ◽  
Vol 136 (12) ◽  
Author(s):  
Marc Gugau ◽  
Harald Roclawski
Keyword(s):  
Fuel Consumption ◽  
Turbine Blade ◽  
Design Parameters ◽  
Speed Ratio ◽  
Element Analysis ◽  
Gasoline Engines ◽  
Turbine Efficiency ◽  
Component Design ◽  
Almost All ◽  
Turbine Design

With emission legislation becoming more stringent within the next years, almost all future internal combustion gasoline engines need to reduce specific fuel consumption, most of them by using turbochargers. Additionally, car manufactures attach high importance to a good drivability, which usually is being quantified as a target torque already available at low engine speeds—reached in transient response operation as fast as possible. These engine requirements result in a challenging turbocharger compressor and turbine design task, since for both not one single operating point needs to be aerodynamically optimized but the components have to provide for the optimum overall compromise for maximum thermodynamic performance. The component design targets are closely related and actually controlled by the matching procedure that fits turbine and compressor to the engine. Inaccuracies in matching a turbine to the engine full load are largely due to the pulsating engine flow characteristic and arise from the necessity of arbitrary turbine map extrapolation toward low turbine blade speed ratios and the deficient estimation of turbine efficiency for low engine speed operating points. This paper addresses the above described standard problems, presenting a methodology that covers almost all aspects of thermodynamic turbine design based on a comparison of radial and mixed-flow turbines. Wheel geometry definition with respect to contrary design objectives is done using computational fluid dynamics (CFD), finite element analysis (FEA), and optimization software. Parametrical turbine models, composed of wheel, volute, and standard piping allow for fast map calculation similar to steady hot gas tests but covering the complete range of engine pulsating mass flow. These extended turbine maps are then used for a particular assessment of turbine power output under unsteady flow admission resulting in an improved steady-state matching quality. Additionally, the effect of various design parameters like either volute sizing or the choice of compressor to turbine diameter ratio on turbine blade speed ratio operating range as well as well as turbine inertia effect is analyzed. Finally, this method enables the designer to comparatively evaluate the ability of a turbine design to accelerate the turbocharger speed for transient engine response while still offering a map characteristic that keeps fuel consumption low at all engine speeds.

scholarly journals Finally, Bulk Typing of Bacterial Species down to Strain Level using ON-rep-seq

2018 ◽  
Author(s):  
Łukasz Krych ◽  
Josué L. Castro-Mejía ◽  
Daniel N. Moesby ◽  
Morten B. Mikkelsen ◽  
Morten A. Rasmussen ◽  
...  
Keyword(s):  
High Speed ◽  
Bacterial Species ◽  
Cost Effective ◽  
Species Level ◽  
Strain Level ◽  
Read Length ◽  
High Quality ◽  
Sequencing Platform ◽  
Culture Independent ◽  
Single Flow

AbstractDespite the massive developments within culture-independent methods for detection and quantification of microorganisms during the last decade, culture-based methods remain a cornerstone in microbiology. We have developed a new method for bacterial DNA enrichment and tagmentation allowing fast (< 24h) and cost-effective species level identification and strain level differentiation using the MinION portable sequencing platform (ON-rep-seq). DNA library preparation takes less than 5h and ensures highly reproducible distribution of reads that can be used to generate strain level specific read length counts profiles (LCp). We have developed a pipeline that by correcting the random error of reads within peaks of LCp generates a set (∼10 contigs per sample; 300bp - 3Kb) of high quality (>99%) consensus reads. Whereas, the information from high quality reads is used to retrieve species level taxonomy, comparison of LCp allows for strain level differentiation. With benchmarked 288 isolates identified on a single flow cell and a theoretical throughput to evaluate over 1000 isolates, our method allows for detailed bacterial identification for less than 2$ per sample at very high speed.

scholarly journals Design, Construction and Simulation of Tesla Turbine

2021 ◽  
Vol 11 (1) ◽  
pp. 84-92
Author(s):  
SMG Akele ◽  
M. Ejededawe ◽  
G. A.Udoekong ◽  
A. Uwadiae ◽  
M. E. Oviawe ◽  
...  
Keyword(s):  
Physical Model ◽  
Model Simulation ◽  
Design Parameters ◽  
Simulation Performance ◽  
Construction Design ◽  
Turbine Efficiency ◽  
Increase With Increase ◽  
Method Of Solution ◽  
Model Geometry ◽  
Turbine Design

Investigations of laminar fluid flow between two moving or stationary plates, and two rotating discs, over the years were geared toward how to increase Tesla-based turbine efficiency. Therefore, this research entails the construction, design and simulation of a Tesla turbine in order to investigate the potential of Tesla turbine for energy generation. Method of solution entails the design and construction of a physical model Tesla turbine from locally sourced materials. The physical model geometry and design parameters were then used to conduct numerical simulation. Performance evaluation was then carried on the physical model and the simulation model. The result showed that voltage, current and power all increase with increase in rev. per minute.  The result obtained indicates that for higher power generation, a Tesla turbine design with higher revolution per minute capability will be required.  Turbine model simulation showed that radial velocity vector to be concentrated at the discs periphery and outlet. The research results are good references for design of larger Tesla turbine for community use.

Combined Cycle Steam Turbine Inlet Flow Passing Capability: Impact on Plant Operation, Turbine Design, and Test Result Accuracy

2011 ◽  
Author(s):  
Thomas P. Winterberger ◽  
Robert A. Ransom
Keyword(s):  
High Pressure ◽  
Steam Turbine ◽  
Combined Cycle ◽  
Turbine Generator ◽  
Turbine Efficiency ◽  
Output Performance ◽  
Flow Capacity ◽  
Pressure Steam ◽  
Sliding Pressure ◽  
Generator Output

The publication of ASME Performance Test Code 6.2-2004 provided the industry with a Code document dedicated to calculating the performance of a steam turbine in a combined cycle power plant. Power output at specified steam flows and conditions was chosen as the Code’s primary performance parameter. That choice was based on the operating and cycle characteristics of a combined cycle plant operating, where the steam turbine is part of the bottoming cycle operating in a sliding pressure mode that follows ambient conditions and the gas turbine operating profile. This steam turbine generator output, corrected to reference heat consumption, is called Output Performance and is a measurement of steam turbine efficiency. Accompanying this new Code was a new correction methodology that focused on correcting the steam turbine generator output to the reference heat consumption of the cycle. In the development of the overall correction methodology, the corrections associated with high-pressure (HP) steam inlet conditions were given careful attention. The committee developing the Code and methodology concluded that three correction formulations were required to accurately and fairly correct back to the reference heat input of the high-pressure turbine inlet, and to account for changes in the as-built flow capacity versus the design flow capacity. The new correction formulations chosen were: • HP Steam Flow; • HP Steam Temperature; • HP Turbine Flow Capacity. Applying these three corrections on a sliding pressure steam turbine ensures that the output performance is corrected to the true reference high pressure steam heat input to the cycle. If any of these three corrections is excluded the calculated output performance will not be a true representation of the steam turbine efficiency.

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