Volume 9: Oil and Gas Applications; Organic Rankine Cycle Power Systems; Steam Turbine最新文献

{"title":"Managing the Pressure to Increase the H2 Capacity Through a Natural Gas Transmission Network","authors":"Francis Bainier, R. Kurz, Philippe Bass","doi":"10.1115/GT2020-14043","DOIUrl":"https://doi.org/10.1115/GT2020-14043","url":null,"abstract":"\u0000 Gas Transmission System Operators (TSO1) are considering injecting hydrogen gas into their networks. Blending hydrogen into the existing natural gas pipeline network appears to be a strategy for storing and delivering renewable energy to markets [1], [2], [3].\u0000 In the paper GT2019-90348 [4], the authors have explored the efficiency of H2-blending in a natural gas pipeline network. The conclusion of the paper is: the energy transmission capacity and the efficiency decrease with the introduction of H2, nevertheless, the authors conclude that it is not an obstacle, but the way of using transmission natural gas networks should be closely studied to find an economic optimum, based both on capital and operating expenses. To establish the comparison, the paper did not take into account the limits of the equipment; all equipment was considered as compatible with any load of hydrogen blending.\u0000 In the current paper, the idea is to consider the hypothesis that the only factor which has impact on the infrastructure is the partial pressure of H2. The idea is not new, in 1802, Dalton published a law called Dalton’s Law of Partial Pressures [5]. Dalton established empirically that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the individual component gases. The partial pressure is the pressure that each gas would exert when it alone occupied the volume of the mixture at the same temperature.\u0000 Independent of the limits of the equipment, the authors explore the relationships between a network capacity and its associated pressures in regards to the H2 partial pressure. Within the partial pressure constraint, the goal is to find the maximum H2 flowrate. This flowrate is then compared with a flowrate which is a function of % H2.\u0000 Nevertheless, steel is subjected to hydrogen invasion while being exposed to hydrogen containing environments during mechanical loading: resulting in hydrogen embrittlement (HE). HE also depends on the textured microstructure. In the final results [6] [7], the measured fatigue data reveals that the fatigue life of steel pipeline is degraded by the added hydrogen. The H2 has an effect on the steel fatigue which is not simply due to the partial pressure.\u0000 The idea of the authors through the results of their 2 papers is to give the key points to help to find the optimum points for introducing H2 into a natural gas network, because, for them, the idea is that partial pressure is a factor in the equilibrium between H2 capacity and the remaining lifetime of the equipment.\u0000 This paper shows the interest of the pressure management. With this management, it is possible to reach a constant H2 injection flow independently of the natural gas flow in the pipeline.\u0000 In conclusion, to optimize the H2 capacity in their current network, a proposal to the TSOs is to adjust their dispatching methodology and their Pipeline Integrity Management (PIM) [8] [9].","PeriodicalId":171265,"journal":{"name":"Volume 9: Oil and Gas Applications; Organic Rankine Cycle Power Systems; Steam Turbine","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129986564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Investigation on the Aerodynamic Performance of a Low-Pressure Steam Turbine Exhaust Hood Using DOE Analysis","authors":"Tommaso Diurno, T. Fondelli, L. Nettis, N. Maceli, Lorenzo Arcangeli, A. Andreini, B. Facchini","doi":"10.1115/GT2020-15993","DOIUrl":"https://doi.org/10.1115/GT2020-15993","url":null,"abstract":"\u0000 Nowadays, the rising interest in using renewable energy for thermal power generation has led to radical changes in steam turbine design practice and operability. Modern steam turbines are required to operate with greater flexibility due to rapid load changes, fast start-up, and frequent shutdowns. This has given rise to great challenges to the exhaust hood system design, which has a great influence on the overall turbine performance converting the kinetic energy leaving the last stage of LP turbine into static pressure.\u0000 The radial hoods are characterized by a complex aerodynamic behavior since the flow turns by 90° in a very short distance and this generates a highly rotational flow structure within the diffuser and exhaust hood outer casing, moreover, the adverse pressure gradient can promote the flow separation drastically reducing the hood recovery performance. For these reasons it is fundamental to design the exhaust system in order to ensure a good pressure recovery under all the machine operating conditions.\u0000 This paper presents a Design of Experiment analysis on a low-pressure steam turbine exhaust hood through CFD simulations. A parametric model of an axial-radial exhaust hood was developed and a sensitivity of exhaust hood performance as a function of key geometrical parameters was carried out, with the aim of optimizing the pressure recovery coefficient and minimizing the overall dimensions of the exhaust casing. Since hood performance strongly depends on a proper coupling with the turbine rear stage, such a stage was modeled using the so-called mixing-plane approach to couple both stator-rotor and rotor-diffuser interfaces. A detailed analysis of the flow field in the exhaust hood in the different configurations was performed, detecting the swirling structures responsible for the energy dissipation in each simulation, as well as correlating the flow field with the pressure recovery coefficient.","PeriodicalId":171265,"journal":{"name":"Volume 9: Oil and Gas Applications; Organic Rankine Cycle Power Systems; Steam Turbine","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132241589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvements of Experimental Research of Wet Steam in Turbines Using CFD Simulations","authors":"M. Kolovratník, Gukchol Jun","doi":"10.1115/GT2020-15018","DOIUrl":"https://doi.org/10.1115/GT2020-15018","url":null,"abstract":"\u0000 The Czech Technical University in Prague (CTU) has been conducting both theoretical and experimental research on wet steam for over 50 years. Part of this research has focused on the development of an instrument for measuring the structure of the liquid phase of wet steam — an optical extinction probe. The measurements of the wet steam structure using our optical extinction probe take place in operative steam turbines. Due to the non-negligible interaction of the probe with the flow field in its vicinity, the wet steam parameters within the probe measuring space change. This probe-flow field interaction (PFFI) negatively affects the accuracy of the measurement of the liquid phase structure.\u0000 This paper presents partial results of our research into the interaction between the optical probe and the surrounding flow field. Particularly, it is the result of CFD simulations of wet steam (WS) flow in the low-pressure section of a 1000 MW nuclear plant steam turbine, in which the probe has been used repeatedly. In the simulations we consider, non-equilibrium condensation allows for the observation of the formation and development of the liquid phase within the turbine. The influence of PFFI on the liquid phase structure is evaluated by a coefficient called the Probe Influence Factor (PIF). In this work, the PIF values are presented for 3 varying traversing positions of the probe along the L-1 stage turbine blade. The use of the PIF to analyse the experimental measurement results is also discussed.\u0000 The second part of the paper deals with the possibility of modifying the shape of the probe measuring head. Based on detailed analysis of the CFD simulations of PFFI, modifying the shape of the probe is proposed to reduce this interaction. The benefit of this change is evaluated using CFD simulations. Comparisons between the PIF coefficients of the original and modified optical probes indicate that modifying the shape may reduce the PFFI influence on experimental measurements.","PeriodicalId":171265,"journal":{"name":"Volume 9: Oil and Gas Applications; Organic Rankine Cycle Power Systems; Steam Turbine","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122750211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Time-Wise Compressor Fouling Phenomenon on a Multistage Test Compressor: Performance Losses and Particle Adhesion","authors":"Alessandro Vulpio, A. Suman, N. Casari, M. Pinelli, R. Kurz, K. Brun","doi":"10.1115/GT2020-15418","DOIUrl":"https://doi.org/10.1115/GT2020-15418","url":null,"abstract":"\u0000 The analysis of the performance losses of a multistage compressor concerning the air contaminant is not widespread in literature and, the mutual interactions of particle materials, air humidity, and compressor load are not well studied. The airborne micrometric particles that enter the compressor can deposit on the internal surfaces, causing the loss of performance of the machine.\u0000 In this paper, several experimental tests have been carried out on a multistage compressor unit. A detailed analysis has been carried out considering soil and soot ingestion, as well as the air relative humidity (ranging from 50 %RH to 80 %RH) and compressor rotating velocity. Several combinations of particle diameter, material, and operating conditions have been considered. The amount of contaminant at the compressor outlet has been measured and the capture efficiency of the whole machine has been determined. Over the exposure time, the capture efficiency ranges from 0.2 to 0.6 according to the powder type and compressor inlet conditions. The capability of the compressor to collect particles changes over time as a function of the condition, even if, several tested cases appear characterized by an almost constant capture efficiency trend.\u0000 In addition, the performance degradation has been monitored over time and, with the reference of the particle concentration, the present experimental campaign covers about 500 operating hours of an actual installation. After a detailed evaluation of experimental uncertainty, the performance losses due to particle contamination has been assessed. The losses in the compressor performance have been estimated by means of the pressure ratio of the axial stages. The maximum degradation has been estimated equal to 0.53 % per hour for the compressor pressure ratio. Soot particles appear stickier, especially in the presence of higher humidity and represent the most detrimental operating conditions for the compressor unit.","PeriodicalId":171265,"journal":{"name":"Volume 9: Oil and Gas Applications; Organic Rankine Cycle Power Systems; Steam Turbine","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115237221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wetness Measurement and Droplet Transport Analysis in Actual Steam Test on a Scaled Low Pressure Turbine","authors":"Y. Sasao, K. Segawa, T. Kudo, Ryousuke Takata, Masaki Osako, S. Yamamoto","doi":"10.1115/GT2020-16117","DOIUrl":"https://doi.org/10.1115/GT2020-16117","url":null,"abstract":"\u0000 Understanding the phenomenon and quantitative prediction of wet loss, quantitative prediction of erosion are still challenges in ST development. The aim of the actual steam test reported in this paper was to verify the performance of a newly developed ST. Still a comprehensive understanding of the wetness phenomenon is also a significant issue. Therefore, in connection with the actual steam test, efforts were made to develop a method for analyzing the three-dimensional causes of wetness loss and erosion. As the first report on the wet phenomenon analysis performed in this actual steam test, this paper reports wet measurement results and analysis results. In the actual steam testing of a 0.33 scaled steam turbine, wetness measurements were carried out at the third stage (L-1) and the final stage (L-0), and its characteristic wetness distribution was analyzed using our original CFD-code MHPS-NT.\u0000 This 0.33 scaled steam turbine consists of the final three stages (LP-end) and the inlet steam conditioning stage (total of four stages), and wetness distributions in the blade height-wise were measured using two different wetness probes under several operating conditions. Wetness distribution did not change linearly with changes in ST inlet temperature, but dynamic changes in peak position and shape were observed. From the ST inlet to the exhaust chamber, the generation of fine droplets, the capturing of droplets by the wall surfaces, and the behavior of water films and coarse droplets were comprehensively analyzed using a three-dimensional (3-D) unsteady Eulerian-Lagrangian coupling solver that takes into account non-equilibrium condensation. This CFD code (MHPS-NT) is an improved version of Original-NT developed by Tohoku University. By considering the relative position and structure of the wet probe and blade cascade in CFD, it was found that the wetness is formed remarkable circumferential distribution by the moisture separation of the upstream blade rows and end-walls. The circumferential distribution of wetness can be a factor that makes it difficult to grasp the liquid phase distribution inside the steam turbine as an error factor independent of the accuracy of the optical measurement device. Due to the effects of water droplet capturing, the LP-end outlet wetness at the design point may be underestimated by 21% relative. It is also reported that because the wetness has a distribution in the meridian direction, wetness measurements by the wet probe may contain measurement errors independent of the measurement accuracy.","PeriodicalId":171265,"journal":{"name":"Volume 9: Oil and Gas Applications; Organic Rankine Cycle Power Systems; Steam Turbine","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115464907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal Load Allocation of Compressors Drivers Taking Advantage of Organic Rankine Cycle As WHR Solution","authors":"M. Bianchi, L. Branchini, A. D. Pascale, F. Melino, A. Peretto, N. Torricelli, R. Kurz, D. Sanchez, N. Rossetti, T. Ferrari","doi":"10.1115/GT2020-14466","DOIUrl":"https://doi.org/10.1115/GT2020-14466","url":null,"abstract":"\u0000 Natural gas demand is projected to continue growing in the long-run and the gas distribution networks are intended to expand with it. The gas compression, along the pipeline, is usually performed in centrifugal compressors driven by gas turbines. In a typical installation, a significant portion of primary energy introduced with natural gas is discharged into the atmosphere with gas turbine exhaust gases, as wasted heat. Since the important investment of the last years, it is of major interest to study solutions for compressor stations, in order to reduce the primary energy consumption and the operative costs. A promising way to enhance the process efficiency, achieving the aforementioned goals, involves recovering compressors drivers wasted heat and converting it into mechanical or electrical energy through an Organic Rankine Cycle (ORC).\u0000 In this study, the feasibility of adding additional compressor capacity inside the station, with the help of an ORC, as waste heat recovery technology, is studied. In particular, the Authors propose a procedure to identify the bottomer cycle optimal size and to re-define the optimal distribution of driver’s loads inside the station. The strategy consists in the resolution of a minimum constrained problem, such as the loads are re-allocated between gas turbines and ORC, in order to minimize the fuel consumption of the station. Constraints of the problem are the load balance of the system and the regulation limits of each units.\u0000 The objectives are: (i) to identify the optimal sizes for ORC and electric motor driven compressor to be installed; (ii) to redefine the optimal distribution of the loads based on an annual operating profile of compressors; (iii) to quantify the environmental savings in terms of CO2 avoided compared to the original set-up of the facility; (iv) to assess the economic feasibility in the presence of additional aspects, as, for example, a carbon tax.\u0000 A typical interstate gas compressor station, with about 24 MW of mechanical drivers installed is taken as case study. Results of the study show that, for the investigated case study, the optimal ORC size turns out to be close to 5.3 MW, which correspond to an additional compressor power consumption of 4.8 MW that can be provided to the ORC driven compressor. Thus, resulting ORC design allows to produce — via an electric motor generator, connecting the ORC and the user — the 18 % of the yearly station mechanical energy demand. A reduction of 22 % of CO2 emissions, compared to the original arrangement is achieved. The economic feasibility of the proposed solution turns out to be very dependent on the natural gas cost and on the carbon tax, if applied. As expected, higher prices lead to higher avoided costs, thus to higher saving and lower payback periods (4 years), whilst low gas prices and no carbon tax can increase the payback period up to 20 years.","PeriodicalId":171265,"journal":{"name":"Volume 9: Oil and Gas Applications; Organic Rankine Cycle Power Systems; Steam Turbine","volume":"86 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132568696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aerodynamic and Structural Numerical Investigation of Full Annulus Last Stage of Steam Turbine Under Low Load Conditions","authors":"Qi Di, Chen Yifeng, Lin Gang, Wenfu Li, Wei Tan","doi":"10.1115/GT2020-16146","DOIUrl":"https://doi.org/10.1115/GT2020-16146","url":null,"abstract":"\u0000 Operating at low load conditions may cause strong and non-synchronous unsteadiness and a high blade dynamic loading for the last stage blades (LSB). Full annulus models should be used to investigate the circumferential asymmetric flow unsteadiness and blade vibrations. Currently, although full annulus models have been applied to numerical aerodynamic studies, to authors’ knowledge, there is still no research including the full annulus in structural analysis due to the high computational cost. In this paper, an unsteady aerodynamic and structural coupled analysis method for an industrial steam turbine LSB using full annulus model under low load conditions is presented. To conduct finite element method (FEM) with limited computational resources, a new structural analysis procedure is proposed to calculate the dynamic stress.\u0000 The aerodynamic analysis is conducted in both steady and unsteady computational fluid dynamics (CFD) calculations. The tip pressure ratio in the steady state calculations is used to predict the aerodynamic loading intensity. The unsteady results indicate typical flow characteristics under low load conditions, which show a big separation region behind the last rotor and tip vortex between last stator and rotor. Unsteady aerodynamic loading is mapped onto the blade surface as the excitation force. The structural analysis is performed to investigate the characteristics of blade vibrations and stress distributions of the full annulus LSB. Repeating the method, a reasonable characteristics curve of vibration stress against flow rates for LSB is calculated.","PeriodicalId":171265,"journal":{"name":"Volume 9: Oil and Gas Applications; Organic Rankine Cycle Power Systems; Steam Turbine","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126693915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LM9000 Passive Clearance Control (PCC)","authors":"S. Marchetti, D. Nappini, R. D. Prosperis, Paolo di Sisto","doi":"10.1115/GT2020-14119","DOIUrl":"https://doi.org/10.1115/GT2020-14119","url":null,"abstract":"\u0000 This paper describes the design of the Free Power Turbine (FPT) of the LM9000, in particularly the design of its Passive Clearance Control (PCC) system.\u0000 The LM9000 is the aero-derivative version of the GE90-115B jet engine. Its core engine has many common parts with the GE90; what differs is the booster (low pressure compressor) and the lower pressure turbine (LPT).\u0000 The booster of the LM9000 is without fan because the engine is not used to provide thrust but torque only, subsequently it has a new flow path [5].\u0000 The LPT has instead been replaced by an intermediate pressure turbine (IPT) and by the FPT. The IPT drives the booster, while the FPT is a free low-pressure turbine designed for both power generation and mechanical drive industrial applications, including LNG production plants.\u0000 Due to its different application, the LM9000 FPT flow path differs sensibly from the GE90 LPT, however as the GE90 it is provided of a clearance control system that cools the casing in order to reduce its radial deflection.\u0000 It is not the first time that a clearance control system has been used in industrial applications; in GE aero-derivative power turbines is already present in the LM6000 and LMS100.\u0000 Design constraints, system complexity, high environment variability because the PCC is located outside the GT, harsh environments and long periods of usage still make the design of this component challenging.\u0000 The design of the PCC has been supported by extensive heat transfer and mechanical simulations. Each PCC component has been addressed with a dedicated life calculation and all the blade and seal clearances have been estimated for all the operating conditions of the engine. Simulations have been validated by an extensive test campaign performed on the first engine.","PeriodicalId":171265,"journal":{"name":"Volume 9: Oil and Gas Applications; Organic Rankine Cycle Power Systems; Steam Turbine","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123832567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Matching of Synchronous Motors and Centrifugal Compressors: Oil and Gas Industry Practice","authors":"Matt Taher, D. Ristanovic, C. Meher-Homji, Pradeep T. Pillai","doi":"10.1115/GT2020-15643","DOIUrl":"https://doi.org/10.1115/GT2020-15643","url":null,"abstract":"\u0000 Synchronous motor driven centrifugal compressors are widely used in the oil and gas industry. In evaluating the optimum selection of synchronous motor drivers for centrifugal compressors, it is important to understand the factors influencing a proper match for a centrifugal compressor and its synchronous motor driver. The buyer should specify process requirements and define possible operating scenarios for the entire life of the motor driven centrifugal compressor train. The compressor designer will use the buyer-specified process conditions to model the aerothermodynamic behavior of the compressor and characterize its performance. Performance, controllability, starting capabilities as well as the optimum power margin required for a future-oriented design must also be considered. This paper reviews the criteria for evaluating the optimal combination of a centrifugal compressor and its synchronous motor driver as an integral package. It also addresses API standard requirements on synchronous motor driven centrifugal compressors. Design considerations for optimal selection and proper sizing of compressor drivers include large starting torque requirements to enable compressor start from settle-out conditions and to prevent flaring are addressed. Start-up capabilities of the motor driver can significantly impact the reliability and operability of the compressor train. API 617 on centrifugal compressors refers to API 546 for synchronous motor drivers. In this paper, requirements of API 617 and 546 are reviewed and several important design and sizing requirements are presented. In the effort to optimize plant design, and maintain the performance requirements, the paper discusses optimization options, such as direct on-line starting method to explore the motor rating limits, and the use of synchronous motors for power factor correction to eliminate or reduce the need for reactive power compensation by capacitor banks. This paper presents a novel approach to show constant reactive power lines on traditional V curves. It also complements capability curves of synchronous motors with lines of constant efficiency. The paper discusses variable frequency drive options currently used for synchronous motors in compressor applications. The paper addresses the available variable frequency drive types, their impact on the electrical grid, and motor design considerations with a view to summarizing factors important to the selection of variable frequency drives.","PeriodicalId":171265,"journal":{"name":"Volume 9: Oil and Gas Applications; Organic Rankine Cycle Power Systems; Steam Turbine","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121775909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Simplified Model for Predicting Natural Draft Wet Cooling Tower Performance of Large Steam Power Plants","authors":"S. Wiesche","doi":"10.1115/GT2020-15369","DOIUrl":"https://doi.org/10.1115/GT2020-15369","url":null,"abstract":"\u0000 Flexible plant operation and rapid load changes become major issues for steam turbine operation. In thermal power plants, the steam turbine performance is closely related to the condenser, and an accurate prediction of coolant temperature as function of changing weather conditions is necessary in order to optimize power plant fleet operation. In this contribution, a one-dimensional model for simulating the performance of large natural draft wet cooling towers is presented. The evaporation zone model rests on the evaporative cooling theory developed by Merkel and Poppe. The off-design behavior of the cooling tower, that is relevant to part load performance, is modeled by an empirical power-law approach. A user-friendly method is presented in order to identify required model parameters by means of already available power plant data. The simulation tool can be employed easily for existing power plants for which the original cooling tower design and construction data lost their validity. The outcome of the present calculation method is successfully compared with field data from representative cooling towers at Middle-European sites.","PeriodicalId":171265,"journal":{"name":"Volume 9: Oil and Gas Applications; Organic Rankine Cycle Power Systems; Steam Turbine","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130451741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}