The Impact of the Gas Temperature and of the Relative Humidity on the Performance of Fans Operating in Drying Plants

2018 ◽  
Author(s):  
Manuel Fritsche ◽  
Philipp Epple ◽  
Antonio Delgado
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Operating Conditions ◽  
Performance Characteristics ◽  
Second Step ◽  
Gas Temperature ◽  
Numerical Computations ◽  
Ansys Cfx ◽  
The Impact ◽  
Similarity Laws

In order to investigate the impact of the gas temperature and its relative humidity on the performance of fans, the similarity laws for fans were extended and verified and numerical computations with the commercial CFD solver ANSYS CFX were performed. First the accuracy of the original fan laws was verified for different operating conditions. In a second step the influence of the temperature on the fan characteristics was investigated. Finally, to include the effect of the relative humidity multiphase simulations with air and water vapor were performed. Therefore, the relative humidity was analyzed for different gas temperatures. In such a way the full influence of the temperature and of the relative humidity on the performance characteristics of radial fans operating in drying plants was obtained. These numerical results have been analyzed in detail and compared with the results predicted by the presented extended similarity laws for turbomachines.

Impact of Operating Conditions and Design Parameters on Gas Turbine Hot Section Creep Life

2010 ◽  
Author(s):  
S. Eshati ◽  
M. F. Abdul Ghafir ◽  
P. Laskaridis ◽  
Y. G. Li
Keyword(s):  
Gas Turbines ◽  
Performance Model ◽  
Operating Conditions ◽  
Creep Model ◽  
Design Parameters ◽  
Gas Temperature ◽  
Creep Life ◽  
Cooling Effectiveness ◽  
Radial Temperature ◽  
The Impact

This paper investigates the relationship between design parameters and creep life consumption of stationary gas turbines using a physics based life model. A representative thermodynamic performance model is used to simulate engine performance. The output from the performance model is used as an input to the physics based model. The model consists of blade sizing model which sizes the HPT blade using the constant nozzle method, mechanical stress model which performs the stress analysis, thermal model which performs thermal analysis by considering the radial distribution of gas temperature, and creep model which using the Larson-miller parameter to calculate the lowest blade creep life. The effect of different parameters including radial temperature distortion factor (RTDF), material properties, cooling effectiveness and turbine entry temperatures (TET) is investigated. The results show that different design parameter combined with a change in operating conditions can significantly affect the creep life of the HPT blade and the location along the span of the blade where the failure could occur. Using lower RTDF the lowest creep life is located at the lower section of the span, whereas at higher RTDF the lowest creep life is located at the upper side of the span. It also shows that at different cooling effectiveness and TET for both materials the lowest blade creep life is located between the mid and the tip of the span. The physics based model was found to be simple and useful tool to investigate the impact of the above parameters on creep life.

On Compressor Station Layout

2003 ◽  
Author(s):  
Rainer Kurz ◽  
Sebouh Ohanian ◽  
Matt Lubomirsky
Keyword(s):  
Gas Turbine ◽  
Electric Motor ◽  
Operating Conditions ◽  
Performance Characteristics ◽  
General Context ◽  
Operational Flexibility ◽  
Gas Engine ◽  
Wide Range ◽  
The Individual ◽  
The Impact

This paper discusses issues that influence the decision on the arrangement of compressors and the type of equipment in gas pipeline compressor stations. Different concepts such as multiple small units versus single large units are considered, both regarding their impact on the individual station and the overall pipeline. The necessity of standby units is discussed. Various concepts for drivers (gas turbine, gas motor and electric motor) and compressors (centrifugal and reciprocating) are analyzed. The importance of considering all possible operating conditions is stressed. With the wide range of possible operating conditions for the pipeline in mind, the discussion will be brought into the general context of operational flexibility, availability, reliability, installation issues, remote control, and operability of gas turbine driven centrifugal compressors compared to other solutions such as electric motor driven compressors or gas engine driven reciprocating compressors. The impact of different concepts on emissions and fuel cost is discussed. Among the assumptions in this paper are the performance characteristics of the compressor. It will be outlined how these performance characteristics influence the conclusions.

scholarly journals Study of the Effects of Changes in Gas Composition as Well as Ambient and Gas Temperature on Errors of Indications of Thermal Gas Meters

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5428 ◽  
Author(s):  
Jacek Jaworski ◽  
Adrian Dudek
Keyword(s):  
Natural Gas ◽  
Physicochemical Properties ◽  
Distribution System ◽  
Test Bench ◽  
Operating Conditions ◽  
Test Method ◽  
Gas Composition ◽  
Gas Temperature ◽  
Metrological Analysis ◽  
The Impact

Thermal gas meters represent a promising technology for billing customers for gaseous fuels, however, it is essential to ensure that measurement accuracy is maintained in the long term and in a broad range of operating conditions. The effect of hydrogen addition to natural gas will change the physicochemical properties of the mixture of natural gas and hydrogen. Such a mixture will be supplied through the gas system, to consumers, including households, where the amounts of received gas will be metered. The physicochemical properties of hydrogen, including the specific density or viscosity, differ significantly from those of the natural gas components, such as methane, ethane, propane, nitrogen, etc. Therefore, it is of utmost importance to establish the impact of the changes in the gas composition caused by the addition of hydrogen to natural gas on the metrological properties of household gas meters, including thermal gas meters. Furthermore, since household gas meters can be installed outdoors and, taking into account the fact that household gas meters are good heat exchangers, the influence of ambient and gas temperature on the metrological properties of those meters should be investigated. This article reviews a test bench and a testing method concerning errors of thermal gas meter indicators using air and natural gas, including the type containing hydrogen. The indication errors for thermal gas meters using air, natural gas and natural gas with an addition of 2%, 4%, 5%, 10% and 15% hydrogen were determined and then subjected to metrological analysis. Moreover, the test method and test bench are discussed and the results of tests on the impact of ambient and gas temperatures (‒25 °C and 55 °C, respectively) on the errors of indications of thermal gas meters are presented. Conclusions for distribution system operators in terms of gas meter selection were drawn based on the test results.

scholarly journals Integrated sensing technologies for detection and location of leaks in water distribution networks

2017 ◽  
Vol 17 (6) ◽  
pp. 1589-1601 ◽  
Author(s):  
Alaa Hawari ◽  
Mohammad Khader ◽  
Walaa Hirzallah ◽  
Tarek Zayed ◽  
Osama Moselhi
Keyword(s):  
Relative Humidity ◽  
Water Distribution ◽  
Accurate Determination ◽  
Distribution Networks ◽  
Operating Conditions ◽  
Water Distribution Networks ◽  
Ir Camera ◽  
Efficient Operation ◽  
Leak Location ◽  
The Impact

Abstract Water distribution networks (WDNs) are infrastructure systems that have high socioeconomic values, for which efficient operation and management are required to ensure minimal amounts of waste which can be represented in the form of leaks. Leak detection is considered as one of the challenges faced by municipalities operating WDNs because it either involves shutting down the system or requires using expensive equipment and technologies. In this paper, a novel noninvasive and nondestructive methodology for detecting leaks in water pipes was tested. Ground penetrating radar was used for accurate determination of pipe location, followed by infrared (IR) thermographic imaging for determining the leak location using four different operating conditions. Results were statistically analyzed using analysis of variance and pairwise comparison methods. Several factors were found to affect the accuracy of the proposed methodology in predicting the leak location, namely, the characteristics of the studied surface (i.e. emissivity), the characteristics of the surrounding environment (i.e. ambient temperature and relative humidity), and the operating conditions of the IR camera (i.e. speed and height of the camera). The results obtained in this study have also shown that under high ambient temperatures and high relative humidity conditions, a higher speed of the IR camera would reduce the impact of noise on the collected thermal contrast and therefore, would give better leak location prediction results. The tested methodology proved the flexibility of the approach and the ability of accurately predicting the leak locations under different conditions.

THE INFLUENCE OF SURFACE LAYER QUALITY ON THE PERFORMANCE CHARACTERISTICS OF MACHINE PARTS UNDER MACHINING

Tribologia ◽  
2018 ◽  
Vol 271 (1) ◽  
pp. 23-29
Author(s):  
Vyacheslav F. BEZYAZYCHNY ◽  
Marian SZCZEREK
Keyword(s):  
Surface Layer ◽  
Quality Parameters ◽  
Operating Conditions ◽  
Performance Characteristics ◽  
Endurance Strength ◽  
Machine Parts ◽  
Surface Layer Quality ◽  
The Impact

The paper highlights the classification of the quality parameters of the surface layer and their influence on the performance characteristics of machine parts, such as wear resistance, long-term and endurance strength, as well as the influence of quality parameters of the surface layer on the performance characteristics subject to the operating conditions (various temperatures and loads). The paper expounds the impact of machining conditions on the formation of surface layer quality indices and provides calculated dependences for the determination of surface layer quality parameters.

Water Vapor and Mechanical Work: A Comparison of Carnot and Steam Cycles

2011 ◽  
Vol 68 (1) ◽  
pp. 91-102 ◽  
Author(s):  
Olivier Pauluis
Keyword(s):  
Energy Source ◽  
Water Vapor ◽  
Relative Humidity ◽  
Latent Heat ◽  
Energy Transport ◽  
Heat Engine ◽  
Bowen Ratio ◽  
Carnot Cycle ◽  
The Impact ◽  
Steam Cycle

Abstract The impact of water vapor on the production of kinetic energy in the atmosphere is discussed here by comparing two idealized heat engines: the Carnot cycle and the steam cycle. A steam cycle transports water from a warm moist source to a colder dryer sink. It acts as a heat engine in which the energy source is the latent heat of evaporation. It is shown here that the amount of work produced by a steam cycle depends on relative humidity and is always less than that produced by the corresponding Carnot cycle. The Carnot and steam cycles can be combined into a mixed cycle that is forced by both sensible and latent heating at the warm source. The work performed depends on four parameters: the total energy transport; the temperature difference between the energy source and sink; the Bowen ratio, which measures the partitioning between the sensible and latent heat transports; and the relative humidity of the atmosphere. The role of relative humidity on the work produced by a steam cycle is discussed in terms of the Gibbs free energy and in terms of the internal entropy production.

Study on Combustion and Emission Performance of Oil Shale Mixed with Coal

2014 ◽  
Vol 521 ◽  
pp. 555-562
Author(s):  
Hai Rong Wang ◽  
Xin Xin Li ◽  
Jian Bo Yan
Keyword(s):  
Oil Shale ◽  
Mass Loss Rate ◽  
Characteristic Parameter ◽  
Simulation Software ◽  
Operating Conditions ◽  
Combustion Characteristic ◽  
Gas Temperature ◽  
Complete Combustion ◽  
Characteristic Index ◽  
The Impact

In this paper, Huadian oil shale from Jilin Province of China was selected as the object of study. Firstly, the ignition temperature, complete combustion temperature, maximum mass loss rate, flammability index C and comprehensive combustion characteristic index S during the separate combustion of oil shale was measured , as well as during the combustion of oil shale mixed with coal, by using the thermo-gravimetric analytical method. Then, the impact of blending ratio on the combustion characteristic parameter was discussed, and conducted modeling for the oil shale blending combustion system was established with the steady-state simulation software program Aspen Plus. Finally, we obtained the exhaust gas temperature, volume flow of gases such as CO, CO2 and SO2, as well as their impacts on the operating conditions of the boiler during the mixing combustion under different excess air coefficients.

Pre-Design of a Continuous Intensified Reactor Based on Pure Thermo-Chemical Optimisation

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Nathalie Di Miceli Raimondi ◽  
Sébastien Elgue ◽  
Laurent Prat ◽  
Patrick Cognet ◽  
Michel Cabassud
Keyword(s):  
Feeding Rate ◽  
Heat Removal ◽  
Operating Conditions ◽  
Second Step ◽  
Batch Operation ◽  
Linear Alkylbenzene ◽  
Precise Information ◽  
The Impact ◽  
Account Heat ◽  
The Ideal

A continuous intensified reactor requires precise information to adapt the design to the reaction to be implemented. In this article we present a two step approach to pre-designing such devices. The first step consists of the optimisation of the operating conditions based only on stoichio-chemical schemes and kinetic laws. This is carried out by adjusting the temperature profile and feeding rate strategy in a batch or pseudo-batch operation. The second step departs from the ideal thermo-kinetic path by taking into account heat removal and reagent injection. A simulator is used to evaluate the impact of these constraints on the selectivity and productivity. The approach is applied to the linear alkylbenzene sulfonation which characteristics present most of the challenges encountered in the intensification. Final results give a pre-design in terms of reactor characteristics (size, injections positions) and operating conditions.

An Investigation of the Influence of Fluidics Insertion Technique on Acetylene/Argon Gas Additives to LPG on the Turbulent Lean Premixed Flame Characteristics for an EV Burner

2018 ◽  
Author(s):  
Sameh H. Hassan ◽  
Ahmed A. Emara ◽  
Mahmoud A. Elkady
Keyword(s):  
Combustion Efficiency ◽  
Flame Stabilization ◽  
Operating Conditions ◽  
Experimental Program ◽  
Temperature Profiles ◽  
Liquefied Petroleum Gas ◽  
Gas Temperature ◽  
Lean Premixed ◽  
The Impact ◽  
Ev Burner

A series of experiments were performed on a vertical EV burner with a constant coflow air of 873 L /min to generate turbulent lean premixed flow in order to study the impact of the addition of Acetylene/Argon mixture to the liquefied petroleum gas (LPG) on the temperature field and flame structure. The fluidics mechanism was inserted at a fixed position inside the entry section of the EV burner assembly. The flow rates of fuel (LPG/C2H2/ Ar) and air were measured using calibrated rotameters. The different volume ratios of the fuel constituents (at a specified fuel flow rate) were admitted via three solenoid valves at the entry section of each stream prior to mixing and monitored using a labview program. The axial temperature profiles at different operating conditions were measured using a bare wire Pt-Pt -10% Rh (type S) thermocouple of wire diameter 250 μm. Flame images were obtained — before and after fluidics insertion — using a high resolution Canon 6D 20MP digital camera. The selection of the different considerated cases was based on flame stability. The experimental program aims at identifying and analyzing the changes in flame characteristics (flame length, axial profiles of mean gas temperature, NOx concentration and overall combustion efficiency) resulting from the insertion of fluidics while considering different proportions of the fuel constituents) (including pure LPG, as a reference case). In all experiments flame stabilization was ensured. The results obtained indicate the following: it was noticed that in most cases of pure LPG only, and other mixtures the images shows increase in both the length and luminosity of the flame as a result of higher degrees of swirl due to the fluidics insertion while the temperature profiles of the different flames were changed. It was indicated that NOx trend was decreased by 52% while the combustion efficiency was improved by 2.5%.

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