Impact of Developments in HEI Correction Factors on Condenser Performance and Operation — A Case Study

2014 ◽  
Author(s):  
Komandur Sunder Raj
Keyword(s):  
Heat Transfer ◽  
Stainless Steel ◽  
Power Plant ◽  
Tube Bundle ◽  
Operational Experience ◽  
Correction Factors ◽  
7Th Edition ◽  
Surface Condenser ◽  
The Impact

The Heat Exchange Institute (HEI) Standards for Steam Surface Condensers were promulgated to design and predict the performance of surface condensers for power plant applications by providing basic overall tube bundle heat transfer rates and correction factors to be applied to account for different tube diameters, wall thicknesses (BWG), tube materials, circulating water inlet temperatures and, average water velocities. From 1958 to 1973, nonferrous alloys were generally the tube materials of choice for steam power plant surface condenser service. By the time the 7th edition of the HEI Standards was issued in 1978, concerns with corrosion and other issues with nonferrous tubing materials had led to increased specification of stainless steel while titanium was still in its infancy. Since then, operational experience gained with stainless steel and titanium coupled with technological advances in these materials have resulted in revisions and incorporation of additional correction factors in subsequent editions of the HEI Standards for Steam Surface Condensers. The latest edition (11th edition) was issued in October 2012. Significant developments in the HEI heat transfer correction factors since issuance of the 7th edition pertain to stainless steel and titanium. Using a case study, this paper analyzes the impact of developments in HEI heat transfer correction factors on steam surface condenser performance and operation with focus on admiralty, austenitic, super-austenitic and super-ferritic stainless steels as well as titanium tube materials. The paper examines how changes in the correction factors affect condenser performance and plant operation. It highlights the importance of using and validating the proper correction factors to predict and ensure optimum condenser performance and operation.

Operational Experience With High Efficiency Cyclones: Comparison Between Boiler A and B in the Zeran Power Plant — Warsaw, Poland

2003 ◽  
Author(s):  
Ireneusz Lalak ◽  
Joachim Seeber ◽  
Frank Kluger ◽  
Stanislaw Krupka
Keyword(s):  
Heat Transfer ◽  
Power Plant ◽  
High Efficiency ◽  
Operational Experience ◽  
Significant Positive Effect ◽  
Internal Circulation ◽  
Technological Developments ◽  
The Impact ◽  
Positive Effect ◽  
Operational Data

The two 450t/h CFB units of the Zeran heat and power plant in Warsaw, Poland, are nearly identical in design, except for the cyclones. While the first CFB unit Zeran A which was commissioned in 1995 had cyclones of a prior design, the second unit Zeran B, which went into operation in late 2001, was equipped with high efficiency cyclones with the latest technological developments. The impact of the cyclone design is clearly visible in the operational data. Due to the high cyclone efficiency, the internal circulation became much higher and the fineness of the circulating particles was shifted to finer particles. As a result, the heat transfer in the furnace was boosted and the temperature profile became more even. This had a significant positive effect on the emissions, especially NOx and on the limestone consumption, which was considerably reduced.

Limitations of Corrosion Resistant Alloy in High CO2 Gas Production Systems: A Case Study

2021 ◽  
Author(s):  
Jorge Rodriguez ◽  
Susana Gómez ◽  
Ngoc Tran Dinh ◽  
Giovanni Ortuño ◽  
Narendra Borole
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
High Pressure ◽  
Stainless Steel ◽  
Carbon Steel ◽  
Material Selection ◽  
Dynamic Modelling ◽  
General Corrosion ◽  
High Co2

Abstract The paper presents the application of a holistic approach to corrosion prediction that overcomes classical pitfalls in corrosion testing and modelling at high pressure, high temperature and high CO2 conditions. Thermodynamic modelling of field and lab conditions allows for more accurate predictions by a novel CO2/H2S general corrosion model validated by laboratory tests. In the proposed workflow, autoclave tests at high pressure and temperature are designed after modeling corrosion in a rigorous thermodynamic framework including fluid-dynamic modelling; the modeled steps include preparation, gas loading and heating of fluid samples at high CO2 concentration, and high flow velocities. An autoclave setup is proposed and validated to simultaneously test different conditions. Corrosion rates are extrapolated to compute service life of the materials and guide material selection. The results from the model and tests extend the application of selected stainless steel grade beyond the threshold conditions calculated by simplistic models and guidelines. Consideration of fugacities and true aqueous compositions allows for accurate thermodynamic representation of field conditions. Computation by rigorous fluid dynamics of shear stress, multiphase flow and heat transfer effects inside completion geometry lead to a proper interpretation of corrosion mechanisms and models to apply. In the case study used to showcase the workflow, conventional stainless steel is validated for most of the tubing. It is observed that some sections of the system in static condition are not exposed to liquid water, allowing for safe use of carbon steel, while as for other critical parts, more noble materials are deemed necessary. Harsh environments pose a challenge to the application of conventional steel materials. The workflow applied to the case study allows accurate representation and application of materials in its application limit region, allowing for safe use of carbon steel or less noble stainless steels in those areas of the completion where corrosion is limited by multiphase fluid-dynamics, heat transfer or the both. The approximation is validated for real case study under high CO2 content, and is considered also valid in the transportation of higher amounts of CO2, for example, in CCUS activities.

scholarly journals Ground vibrations caused by wind power plant work as environmental pollution - case study

2019 ◽  
Vol 302 ◽  
pp. 01002
Author(s):  
Sylwester Borowski
Keyword(s):  
Power Plant ◽  
Environmental Pollution ◽  
Wind Power ◽  
Wind Farms ◽  
Wind Power Plant ◽  
Ground Vibrations ◽  
Living Organisms ◽  
The Impact

The paper presents issues related to the impact of wind farms on the environment. Emphasis was placed on vibrations that are transferred to the ground through the foundations. As research has shown - a case study - vibrations are felt up to about 1000 m from wind farms. According to other literature sources, this may affect living organisms in the ground.

scholarly journals An Exploration of The Key Issues and Challenges in Implementing Public-Private Partnerships: A Case Study of The Central Java Power Plant Project, Indonesia

2021 ◽  
Author(s):  
◽  
Fikriyatul Falashifah
Keyword(s):  
Power Plant ◽  
Social Issues ◽  
Natural Capital ◽  
National Level ◽  
Public Private Partnerships ◽  
Alternative Mechanism ◽  
Sustainable Livelihood ◽  
Central Java ◽  
The Impact

<p>Over the last two decades, Indonesia began to implement Public-Private Partnerships (PPPs) to provide an alternative mechanism for providing public infrastructure. The need to accelerate development, fulfil national demands and address mounting fiscal constraints are the reasons behind choosing PPP approach. One of the infrastructure projects using PPP mechanisms in Indonesia is Central Java Power Plant (CJPP) project, which is claimed to be the largest power plant in Southeast Asia. The project bidding was won by three consortia including ITOCHU Corporation, Adaro Power and J-Power, while the Government of Indonesia provided a guarantee for this project through the Ministry of Finance (MoF) and the Indonesia Infrastructure Guarantee Fund (IIGF). The project is built under Build, Operate, Own, and Transfer (BOOT) PPP model.  In continuing academic research about PPP in general and CJPP in particular, this study was conducted with the aim of exploring critical issues and challenges in implementing PPPs in CJPP project. Three issues were chosen for particular examination, including governance, environment and social issues. This study was conducted by adopting a qualitative approach under a constructivist epistemology to gain meaning and knowledge from certain phenomena or specific circumstances, in this case, by using CJPP as a single case study. Document reviews, semi-structured interviews, and unstructured observation were carried out from July to September 2018 to gain information and perspectives from multilevel stakeholders who are in charge, involved in and were impacted by the implementation of PPP mechanism in CJPP. Stakeholder Analysis and Sustainable Livelihood Approach were taken as the framework for data analysis.  This study found that top-down approach applied to implementing PPP in CJPP project left some governance issues and dynamics about power relations and regulations; conflicting stakeholders’ interests; communication and knowledge gaps; and dualism perspectives for viewing the scheme. The Governments of Central Java and Batang Regency underwent difficulties in structuring and implementing Environmental and Social Impact Assessment (ESIA), or in Bahasa Indonesia known as AMDAL. Meanwhile, coal, the major resource that will be utilised in this project, faces issues surrounding its emissions, stock, and sustainability. Several issues regarding five forms of capital for sustainable livelihood – human capital, social capital, economic capital, natural capital and physical capital – also arose during the project period. These issues included differing perspectives and sentiments among the surrounding societies and economic inequalities, as well as cultural and migration issues.  It is hoped that this research can inform our understanding of PPP implementation, both in policy and in practice. Based on this study, PPP practice at the national level should standardise documents and processes as well as having project assistance. At the regional level, the local government must be more empowered regarding their roles, responsibilities and resource management. Moreover, the impact of PPP on environment and society should be more precisely predicted and managed.</p>

scholarly journals The Impact of Soil Hydrothermal Properties on Geothermal Power Generation (GPG): Modeling and Analysis

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 448
Author(s):  
Zhengguang Liu ◽  
Gaoyang Hou ◽  
Ying Song ◽  
Hessam Taherian ◽  
Shuaiwei Qi
Keyword(s):  
Heat Transfer ◽  
Power Generation ◽  
Porous Media ◽  
Power Plant ◽  
Geothermal Energy ◽  
Collection Efficiency ◽  
Porous Media Flow ◽  
Geothermal Power Plant ◽  
Geothermal Power ◽  
The Impact

Geothermal power plants have become the main application that utilizes geothermal energy. The utilization of deep geothermal energy adheres great importance to the soil condition. One of the biggest challenges faced by geothermal power plant designers is to reduce the risk of soil exploration. To solve this problem, forecasting by modeling has proven to be an important tool to address the problem. In this research, a geo-model was established by modeling three geological layers with different hydraulic and thermal properties to solve the above dilemma. The layers, elevation, and fault zones were simulated using interpolation functions from an artificial dataset. The coupled porous media flow and heat transfer problem using Darcy’s law, as well as heat transfer in porous media interfaces, were studied. The evolution of the flow field, hydrothermal performance, and temperature gradient were also analyzed for a period of 10 years. The results showed the recoverable thermal energy area gradually moved downwards during the 10-year simulation time. When the distance between the recharge well and the production well exceeded 200 m, the collection efficiency was significantly decreased. After 5 years of extraction, the power generation efficiency of the heat source will be less than 9.75%. These results effectively avoided the exploration cost of geothermal power plant site selection, which is significant for the efficiency improvement of geothermal energy.

scholarly journals Impact of Tube Bundle Placement on the Thermal Charging of a Latent Heat Storage Unit

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1289
Author(s):  
Mohammad Ghalambaz ◽  
Amir Hossein Eisapour ◽  
Hayder I. Mohammed ◽  
Mohammad S. Islam ◽  
Obai Younis ◽  
...  
Keyword(s):  
Heat Transfer ◽  
General Circulation ◽  
Liquid Fraction ◽  
Tube Bundle ◽  
Melting Rate ◽  
Heat Transfer Fluid ◽  
Storage Unit ◽  
Latent Heat Storage ◽  
Four Levels ◽  
The Impact

The melting process of a multi-tube’s thermal energy storage system in the existence of free convection effects is a non-linear and important problem. The placement of heated tubes could change the convective thermal circulation. In the present study, the impact of the position of seven heat exchanger tubes was systematically investigated. The energy charging process was numerically studied utilizing liquid fraction and stored energy with exhaustive temperature outlines. The tubes of heat transfer fluid were presumed in the unit with different locations. The unit’s heat transfer behavior was assessed by studying the liquid fraction graphs, streamlines, and isotherm contours. Each of the design factors was divided into four levels. To better investigate the design space for the accounted five variables and four levels, an L16 orthogonal table was considered. Changing the location of tubes could change the melting rate by 28%. The best melting rate was 94% after four hours of charging. It was found that the tubes with close distance could overheat each other and reduce the total heat transfer. The study of isotherms and streamlines showed the general circulation of natural convection flows at the final stage of melting was the most crucial factor in the melting of top regions of the unit and reduces the charging time. Thus, particular attention to the tubes’ placement should be made so that the phase change material could be quickly melted at both ends of a unit.

Analysis of Flow and Heat Transfer at a Finned Tube in Crossflow

2003 ◽  
Author(s):  
Bharat K. Rangan ◽  
Adarsh Krishnamurthy ◽  
Vijay R. Raghavan
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Fundamental Problem ◽  
Tube Bundle ◽  
Cylindrical Tube ◽  
Finned Tube ◽  
Outer Diameter ◽  
Duct Wall ◽  
The Impact ◽  
Fin Spacing

In the present study, a numerical investigation has been carried out into the fundamental problem of airflow past and heat transfer from a circular finned cylindrical tube, placed in a duct. The simulation is carried out using a finite volume method, based on laminar calculation of the transport quantities and employs an unsteady, 3-D, second order upwind scheme. As the work has importance in applications of air-cooled heat exchangers, practical values have been chosen for air velocity, air temperature, fin spacing and clearance between fin outer diameter and duct wall. In experimental determination of the performance of a finned-tube bundle, only overall average values such as drag coefficient and overall Nusselt number are possible. Local measurements are well nigh impossible, as any measurement instrument introduced into the narrow fin space will immediately change the flow field. This work gives an insight into variations of shear and heat transfer that will help the designer to optimize the fin spacing. The validity of the results for instantaneous velocity profiles and Nusselt number distribution comes from their physical plausibility. The agreement of the logical behavior of the studied variables when the fin space or fin clearance is modeled confirms the adequacy of the numerical simulation. The strong viscous effects caused by decreasing the fin space result in an increase in Cd and change in its frequency. Vortices generated on the rear section of the tube are damped, but the flow still shows small oscillations downstream of the tube, which indicates that vortex generation still exists, but has changed its location. Vortices augment the Nusselt number locally with increasing fin distance. Simultaneously, the opposite effect of converging boundary layers and therefore accelerated core flow in the fin space yields a maximum in the average Nusselt number as a function of fin space. The impact of decrease in the clearance between the tube and the duct wall is not as important as the effects of fin space.

Sign in / Sign up

Export Citation Format

Share Document