What’s Wrong With Thermal Performance Engineering?

2007 ◽  
Author(s):  
Tom Canning ◽  
Kenneth F. Horn ◽  
Jeffrey A. Karloff ◽  
Fred D. Lang ◽  
Dave A. T. Rodgers ◽  
...  
Keyword(s):  
North America ◽  
Thermal Performance ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Western Europe ◽  
Heat Rate ◽  
Capital Projects ◽  
Performance Engineering ◽  
The Past ◽  
Hands On

This paper discusses experiences and recommendations of six practicing thermal performance engineers with regards improving and maintaining the thermal efficiency of power plants. It discusses the authors’ perceived decline over the past decade for qualified staff, and capital projects involving efficiency improvements, instrumentation and testing/monitoring projects. Such observations extend to North America and Western Europe. This paper attempts to coalesce years of observations and hands-on experience in the field into summaries useful for prudent action. It also presents several recommendations aimed at improving the consciousness towards performance engineering, which has the potential of substantially reducing emissions per electrical output, and increasing the mostly forgotten thermal efficiencies of power plants (heat rate).

Variability in Thermal Performance and Measured Heat Rate in Fossil-Fuelled Power Plants

1992 ◽  
Vol 206 (2) ◽  
pp. 109-123 ◽  
Author(s):  
F L Carvalho ◽  
F H D Conradie ◽  
H Kuerten ◽  
F J McDyer
Keyword(s):  
Thermal Performance ◽  
Power Plants ◽  
Performance Monitoring ◽  
Unit Commitment ◽  
Thermal Power ◽  
Heat Rate ◽  
Plant Performance ◽  
Plant Management ◽  
Fuel Quality ◽  
Stable Operating

The paper examines the variability of key parameters in the operation of ten thermal power plants in various commercial grid environments with a view to assessing the viability of ‘on-demand’ plant performance monitoring for heat rate declaration. The plants of various types are limited to coal- and oil-fired units in the capacity range of 305–690 MW generated output. The paper illustrates the influence of control system configuration on effective and flexible power plant management. The analysis of variability indicates that there is a reasonable probability of achieving adequately stable operating periods within the normal operating envelope of grid dispatch instructions when thermal performance monitoring and display can be undertaken with a high confidence level. The levels of variability in fuel quality, which were measured during nominally constant levels of fuel input and generated output, range from about +1 per cent for oil-fired plants to about ±5 per cent for coal-fired power plants. The implications of adopting on-line monitoring of unit heat rate as an input to the generation ordering and unit commitment process are potentially significant cost and energy conservation benefits for utilities having a high proportion of coal- and oil-fired generation.

Availability Balance of Steam Power Plants

1959 ◽  
Vol 81 (1) ◽  
pp. 35-42 ◽  
Author(s):  
C. A. Meyer ◽  
G. J. Silvestri ◽  
J. A. Martin
Keyword(s):  
Thermal Efficiency ◽  
Power Plants ◽  
Heat Rate ◽  
Development Effort ◽  
Combustion Gases ◽  
Steam Power Plants ◽  
Reheat Steam ◽  
Temperature Combustion ◽  
The Difference ◽  
Average Plant

The well-known expression for availability, b = h − T0s, is developed in a simple yet general manner. The changes in availability throughout several typical single and double reheat steam plants having different steam conditions have been calculated. Balances of availability are presented for each of the several plants. These balances show the net plant output as the difference between the availability added in the boiler and the various losses in availability throughout the plant. The maximum plant thermal efficiency (or minimum heat rate) is easily obtained from the ratio of the increase in availability to the heat added in the boiler. The availability balances present in fine detail the loss distribution throughout the plant. Some very interesting results are obtained. For example, an assumed average plant will have a calculated maximum thermal efficiency of about 75 per cent based on the ratio of the availability and the heat in the high temperature combustion gases. Due to the heat transfer through a temperature difference, this value is reduced to 50 per cent when based on the ratio of the availability and the heat added to the steam in the boiler. This average plant will lose an additional 10 points in thermal efficiency, due to internal losses in availability, resulting in a 40 per cent thermal efficiency (excluding boiler and auxiliary losses). These latter 10 points due to internal losses are roughly divided as follows: Pressure drop: 0.9 Turbine blading: 5.0 Turbine leakage: 0.6 Turbine leaving and hood: 1.0 Mechanical and generator: 0.7 Feed and healing system: 1.3 and Feed pump and motor inefficiency: 0.5 Total: 10.0 An availability balance enables one to make an accurate assessment of the losses in any power plant and therefore serves as a very accurate guide in directing development effort toward reducing the more significant losses.

Is Your Power Plant Headed for a HILP? How to Avoid, Detect or Mitigate High Impact–Low Probability (HILP) Events

2008 ◽  
Author(s):  
Robert R. Richwine ◽  
G. Scott Stallard ◽  
G. Michael Curley
Keyword(s):  
Power Plant ◽  
North America ◽  
North American ◽  
Power Plants ◽  
High Impact ◽  
Root Cause ◽  
The Past ◽  
The North ◽  
Sufficient Detail ◽  
Low Probability

In recent years some power companies have instituted programs aimed at reducing or eliminating their power plants’ unreliability caused by abnormal events that occur infrequently but result in extended unplanned outages when they do occur, i.e. High Impact–Low Probability events (HILPs). HILPs include catastrophic events such as turbine water induction, boiler explosions, generator winding failures, etc. Many of these successful programs have relied on the detailed reliability data contained in the North American Electric Reliability Corporation’s (NERC) Generating Availability Data System (GADS) that contains data collected over the past 25 years from 5000+ generating units in North America. Using this data, these companies have been able to 1) benchmark their fleet’s unreliability due to HILPs against their North American peers, 2) prioritize their peer group’s susceptibility to various HILP modes and 3) use root cause data contained within the NERC-GADS data base to help identify and evaluate ways to proactively prevent, detect and/or mitigate the consequences of HILP events. This paper will describe the methods used in these successful programs in sufficient detail to enable others to adopt the techniques for application at their own generating plants.

Using CFD Simulations to Improve the Air-Cooled Steam Condenser Performance in Severe Windy Conditions via Proper Tuning of Blades Pitch Angles

2018 ◽  
Author(s):  
Masoud Darbandi ◽  
Hamid Reza Khorshidi Behzadi ◽  
Vahid Farhangmehr ◽  
Gerry E. Schneider
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Power Plants ◽  
Thermal Power ◽  
Research Work ◽  
Convection Heat Transfer ◽  
Heat Rate ◽  
Cost Effective ◽  
Cold Air

The use of air-cooled steam condenser (ACSC) in thermal power plants has become so normal since a few decades ago. It is because there are so many valuable advantages with the ACSC implementation, e.g., little dependency on water consumption and benefiting from the forced convection heat transfer instead of the natural one to condense the steam. However, the thermal performance of an ACSC can be readily defected by the ambient wind; specifically, when the ambient temperature is high. This research work benefits from the computational fluid dynamics tool to study the details of ACSC’s thermal performance in such undesirable ambient windy conditions. Furthermore, this work suggests an effective remedy to increase the heat rate from the proposed ACSC. Evidently, the flow rate of cold air through the heat exchangers of proposed ACSC has direct influence in heat transfer rate from the heat exchangers of ACSC. One remedy to achieve higher cold air flow rates through these heat exchangers is to improve the design of its fans or blowers. However, for an ACSC already in service, one should look for other cost-effective remedies. So, if one wishes to improve the performance of those fans without changing their design one should pay attention to some other simple ways with little costs to implement them. This work suggests to tune up the pitch angles of blades of ACSC’s fans properly. The details of implementing this remedy are presented in this paper.

Thermal Performance of Steam Receiver in Tower-Type Solar Power Plants

2017 ◽  
Author(s):  
Kai Yan ◽  
Xiaojiang Wu ◽  
Jianbin Liu
Keyword(s):  
Heat Transfer ◽  
Heat Loss ◽  
Thermal Performance ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Solar Power ◽  
Working Fluid ◽  
Receiver Design ◽  
Solar Power Plants ◽  
Performance Calculation

In this paper, the thermal performance of steam receiver in tower-type solar power plants has been performed using the tower-type solar receiver design program developed by Shanghai boiler works Co Ltd. In the program, the integrated effect of three types of heat transfer, i.e. heat conduction, convection and radiation, in the process of heat transfer of receivers has been considered. With integrating the characteristics and the working conditions of receivers of both steam and molten salt, the developed program can be used to perform the thermal performance calculations for the receivers of both working fluids. The proposed program was validated through Solar Two project and the satisfactory results achieve. A steam receiver in a tower-type solar power plant with double superheats is selected as an example for thermal performance calculation. In view of the receiver operating in subcritical status, the thermal performance calculation is carried out for two sections, the one for evaporation and that for superheat. In evaporation section, the working fluid is circulated with a circulating pump at a very high circulating ratio. At the outlet of panels, the qualities of working fluid can reach to maximum about 0.35. Besides, the great difference of qualities of working fluid at the outlet of panels is observed. Even for some pipes of some panels, the working fluid at the outlet is in liquid phase. The distribution of metal temperature at fin end of panels in the evaporation region varies dramatically from place to place and reaches to over 520 °C. In superheat region, the temperature of the outer front crown of tubes is concerned. The highest front point temperature of pipe, which reaches to maximum over 660 °C, is in the middle region of the last parts of the primary superheat pass. The thermal efficiency distribution of the receiver, including the evaporation and the superheat regions, are also performed. The results show that the averaged efficiency is about 86%. Besides, the phenomenon of negative thermal efficiency happens in both two regions. That is because the solar incidence cannot compensate the natural heat loss due to incident radiation reflection, the pipe wall infrared radiation and convective heat loss.

scholarly journals The Prevalence of Huntington's Disease

2016 ◽  
Vol 46 (2) ◽  
pp. 144-153 ◽  
Author(s):  
Michael D. Rawlins ◽  
Nancy S. Wexler ◽  
Alice R. Wexler ◽  
Sarah J. Tabrizi ◽  
Ian Douglas ◽  
...  
Keyword(s):  
North America ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Lower Incidence ◽  
Western Europe ◽  
The Past ◽  
Case Ascertainment ◽  
Asian Populations ◽  
The United Kingdom ◽  
Geographical Regions

Background: Reviews of the epidemiology of Huntington's disease (HD) suggest that its worldwide prevalence varies widely. This review was undertaken to confirm these observations, to assess the extent to which differences in case-ascertainment and/or diagnosis might be responsible, and to investigate whether the prevalence pattern has changed over the past 50 years. Methods: Eighty two relevant studies were identified from Medline and Embase, previous reviews, scrutiny of references from included and excluded studies and enquiry among those interested in the field. Results: The lowest rates were among the Asians and the highest among the Caucasians. The differences are not fully explained by varying approaches to case-ascertainment or diagnosis. There was evidence of an increasing prevalence of between 15 and 20% per decade in studies from Australia, North America and Western Europe. Conclusions: The prevalence of HD varies more than tenfold between different geographical regions. This variation can in part be attributed to differences in case-ascertainment and/or diagnostic criteria, but there is consistent evidence of a lower incidence in Asian populations. There is also evidence that in Australia, North America and in Western Europe (including the United Kingdom), prevalence has increased over the past 50 plus years.

Variation of Plant Electrical Output Due to Main Steam Temperature and Thermal Power

2010 ◽  
Author(s):  
D. W. Yoon ◽  
C. K. Park ◽  
B. H. Lee ◽  
K. C. Jeong
Keyword(s):  
Power Plant ◽  
Thermal Performance ◽  
Thermal Efficiency ◽  
Thermal Power ◽  
Heat Rate ◽  
Steam Temperature ◽  
Turbine Inlet ◽  
Thermodynamic Performance ◽  
Main Steam ◽  
Electrical Output

As a measure of power plant thermodynamic performance, heat rate (H.R.) is used. As heat rate is inversely proportional to thermal efficiency, the thermal efficiency of a power plant increases as the heat rate decreases. The major thermodynamic performance parameters in a plant thermal cycle affecting the electrical output include but are not limited to: the initial pressure of main steam at the turbine inlet, the initial moisture content or superheated condition of main steam at the turbine inlet, the effectiveness of the feedwater heating cycle, the effectiveness of the moisture separator, the effectiveness of the reheater, the condenser pressure, the level of cycle separation and the accuracy of electric output measurement. A review of thermodynamic principles involved in a thermal performance plan is needed to understand the changes in the parameters and recognize the thermal performance status and trends, which will lead us to propose corrective actions when appropriate. This paper focuses on the effects of main steam temperature and thermal power.

Cassette Tape Revival as Creative Anachronism

2017 ◽  
Vol 14 (1) ◽  
pp. 109-117 ◽  
Author(s):  
JOANNA DEMERS
Keyword(s):  
North America ◽  
Popular Music ◽  
Data Storage ◽  
Western Europe ◽  
Cassette Tape ◽  
Hard Drives ◽  
The Past ◽  
Streaming Services

ABSTRACTListeners of a certain age tend to think that the cassette tape fell out of favour sometime during the 1990s, but is experiencing a revival of sorts as curious Millennials discover the pleasures of mixtapes and decaying media. But cassette tapes have been in constant use since their invention in 1963. Outside of North America and Western Europe, the tape is still the predominant phonographic medium, and is unseating hard drives as the preferred medium for data storage. For whom, then, is this a revival? My article argues that the tape revival is less an attempt at neutral recuperation of the past than a purposeful rewriting of history. Cassettes are particularly potent because they signify death and decay more forcefully even than vinyl. Their acoustic imperfections and mechanical frailties are now aestheticized in novels and contemporary popular music. Even curated listening experiences, from podcasts to streaming services, are designed to replicate the mixtape. The second era of the cassette tape represents another example of Simon Reynolds’ concept of retromania, and can be fruitfully understood as a chapter in the evolving story of phonographic waste.

scholarly journals Foreign Experience of Legal Support Privatization and the Possibility of its Use in Ukraine

2021 ◽  
Vol 9 (3) ◽  
pp. 505-516
Author(s):  
Roman Victorovich Myroniuk ◽  
Anatolii Matviichuk ◽  
Olena Hrabylnikova ◽  
Olesia Marchenko
Keyword(s):  
Economic Development ◽  
North America ◽  
Western Europe ◽  
The State ◽  
Main Attention ◽  
The Past ◽  
Legal Enforcement ◽  
Effective Activity ◽  
Foreign Countries ◽  
Legitimate Interests

Successful examples of legal support privatization in a number of developed foreign countries are analyzed. In particular, the main attention was paid to the analysis of the experience of legal support privatization in developed and democratic countries of North America and Western Europe. The possibility and peculiarity of the procedure of introduction of specific forms and methods of legal support of the processes related to privatization in Ukraine are established. It is stated that privatization is one of the most significant phenomena both in the economy of a particular state and in society as a whole. It is noted that the proper legal enforcement and support of all privatization-related processes determine whether the economic development and prosperity of the state will take place, or, conversely, it will decline and suffer significant losses. It is noted that in connection with the gradual rapprochement of Ukraine with European states and their standards, the problem of inventing the most appropriate and relevant privatization of certain state or municipal enterprises is becoming more acute. At the same time, researchers prefer to conduct a qualitative analysis of the processes of privatization of state property that has taken place in the past in more detail, based on certain newly discovered facts. Among other things, it is considered necessary to check whether the rights, freedoms and legitimate interests of citizens, as well as the state, have been violated during the privatization process.Keywords: Privatization Legal Support; Implementation; Effective Activity; Qualitative Regulation; Research of Processes and PhenomenaPengalaman Asing Dalam Privatisasi Dukungan Hukum dan Peluang Penerapannya di Ukraina AbstrakContoh sukses privatisasi dukungan hukum di sejumlah negara maju asing dianalisis. Secara khusus, perhatian utama diberikan pada analisis pengalaman privatisasi dukungan hukum di negara-negara maju dan demokratis di Amerika Utara dan Eropa Barat. Kemungkinan dan kekhasan prosedur pengenalan bentuk khusus dan metode dukungan hukum dari proses yang terkait dengan privatisasi di Ukraina ditetapkan. Disebutkan bahwa privatisasi adalah salah satu fenomena paling signifikan baik dalam perekonomian suatu negara tertentu maupun dalam masyarakat secara keseluruhan. Penegakan hukum yang tepat dan dukungan dari semua proses terkait privatisasi menentukan apakah pembangunan ekonomi dan kemakmuran negara akan berlangsung, atau sebaliknya, akan menurun dan menderita kerugian yang signifikan. Sehubungan dengan pemulihan hubungan Ukraina secara bertahap dengan negara-negara Eropa dan standar mereka, masalah menciptakan privatisasi yang paling tepat dan relevan dari perusahaan negara bagian atau kota tertentu menjadi lebih akut. Pada saat yang sama, peneliti lebih memilih untuk melakukan analisis kualitatif terhadap proses privatisasi barang milik negara yang telah terjadi di masa lalu secara lebih rinci, berdasarkan fakta-fakta tertentu yang baru ditemukan. Antara lain, dipandang perlu untuk memeriksa apakah hak, kebebasan, dan kepentingan sah warga negara, serta negara, telah dilanggar selama proses privatisasi.Kata Kunci: Dukungan Hukum Privatisasi; Pelaksanaan; Kegiatan Efektif; Regulasi Kualitatif; Penelitian Proses dan Fenomena. Зарубежный опыт правового обеспечения приватизации и возможность его использования в УкраинеАннотацияПроанализированы успешные примеры правового обеспечения приватизации в ряде развитых зарубежных стран. В частности, основное внимание было уделено анализу опыта правового обеспечения приватизации в развитых и демократических странах Северной Америки и Западной Европы. Установлены особенность процедуры введения конкретных форм и методов правового обеспечения процессов, связанных с приватизацией в Украине. Констатировано, что приватизация является одной из наиболее значимых явлений как в экономике конкретного государства, так и в обществе в целом. От надлежащего правового обеспечения и сопровождения всех связанных с приватизацией процессов зависит будет ли происходить экономическое развитие и процветание государства, или же наоборот она испытывает упадок и получит существенные убытки. В связи с постепенным приближением Украины к европейским государствам и их стандартов, все более остро встает проблема изобретение наиболее уместного и актуального проведения приватизации определенных государственных или коммунальных предприятий. Вместе с тем, исследователи предпочитают более детализировано, опираясь на определенные вновь открывшиеся факты, провести качественный анализ тех процессов приватизации государственной собственности, которые произошли в прошлом. Среди прочего, признается необходимым проверить, не были ли нарушены при проведении приватизации права, свободы и законные интересы граждан, а также интересы государства.Ключевые слова: приватизация, правовое обеспечение, эффективная деятельность, качественная регламентация, исследования процессов и явлений

scholarly journals Motivational and Personality Sphere in Mothers of Autist Children: North America and Western Europe

2016 ◽  
Vol 8 (1) ◽  
pp. 128-136
Author(s):  
A.A. Kukanov ◽  
E.B. Fantalova
Keyword(s):  
North America ◽  
Western Europe ◽  
Autistic Spectrum Disorder ◽  
Spectrum Disorder ◽  
Autistic Spectrum ◽  
Number Of Children ◽  
The Past ◽  
Number Of Factors ◽  
Negative Emotional State ◽  
Emotional Burnout

Over the past decade the number of children under the age of three years, who were diagnosed with autism or autistic spectrum disorder is rapidly increasing in the countries of North America and Western Europe. Researchers noted a sharp deterioration in the psychological and physical health of mothers of autistic children, resulting in the high levels of stress, depression and anxiety disorders, emotional burnout. Therefore, authors of this article give a review of scientific theses and papers published over the past 15 years devoted to the study of specific features of the mental state in mothers of children with a diagnosis of Autistic Spectrum Disorder (autism), published in North America (US and Canada) and Western Europe (United Kingdom, Netherlands, Sweden, etc.) We also highlighted a number of factors contributing to the negative emotional state of mothers and compensatory resources to help them to coping with the situation.

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