Update on IEEE Working Group 622-electrical heat tracing systems(IEEE 622) and related standards

IEEE 622 Working Group has produced three recommended practices that are available through IEEE publications. The subject of these practices is electric heat tracing systems. IEEE Std 622-1987 (IEEE Recommended Practice for the Design and Installation of Electric Heat Tracing Systems for Nuclear Power Generating Stations) was originally issued in 1979 as a document specifically for use in nuclear power plants. This document was updated in 1987. The second document. IEEE 622A-1984 (IEEE Recommended Practice for the Design and installation of Electric Pipe Heating Control and Alarm Systems for Power Generation Stations), addresses the control and alarm systems for heat tracing systems, both nuclear and fossil. The third document IEEE 622B-1988 (IEEE Recommended Practice for Testing and Startup Procedures for Electric Heat Tracing Systems for Power Generating Stations) completes the series with the recommendations for commissioning the heat tracing systems. The working group proposes to combine the three documents into one. IEEE 622A and IEEE 622B continually refer to IEEE 622-1987 and the combination is not only justified but necessary in the interests of conciseness and ease of use. Other documents related to electric heat tracing are mentioned, and additional updates are discussed. Future tasks of the group are mentioned     

IEEE Power Engineering Review

In the late 1970s, the US Navy recognized that electrical fires were becoming a major problem in submarines. Approximately three fires per year were occurring in the main electrical distribution switchboards across the submarine fleet. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) worked with the Navy to design two basic arc fault detection (AFD) and continuous thermal monitoring (CTM) systems. The first systems were designed using all military-specification (Mil-Spec) hardware. At that point in time, Mil-Spec hardware greatly increased system reliability but it drove up the system cost. The most recent systems were designed using commercial-off-the-shelf (COTS) assemblies and parts and are cost effective for commercial use. These systems have proven effective in 450 V AC, 4160 V AC, and 700 V DC switchboards. The timing on the systems is adjustable to allow for optimum usage with air circuit breakers or sealed breakers. While the AFD/CTM systems have seen extensive use in military ships, they are equally suited for the protection of all types of critical switchboards. Commercial ships, power generation facilities, power distribution switchboards, hospitals, web hosting facilities, etc., could all benefit from the increase in power reliability offered by this type of technology. These systems can be included in the original design of the switchboard or installed in existing switchboards with equal ease.     

Heat transfer for Herschel–Bulkley fluids in the entrance region of a rectangular duct

In this study, we present a numerical solution for combined laminar fluid flow and heat transfer of Herschel–Bulkley non-Newtonian fluids in the entrance region of a rectangular duct. The governing equations are solved iteratively by using finite difference method to obtain temperature, bulk temperature, and Nusselt number. Two cases of the thermal boundary conditions are considered; (i) T thermal boundary condition “constant temperature at the wall” and (ii) H2 thermal boundary condition “constant heat flux at the wall”. The results are presented in tables and figures for different parameters for the fluid and the duct geometry.     

Aspects of second-order velocity slip and radiation absorption on hydromagnetic stagnation point flow of Jeffrey fluid with chemical reaction

The present article describes the magnetohydrodynamic flow of a moving Jeffrey fluid along a convectively heated porous stretching surface with second-order velocity slip and radiation absorption effects. Furthermore, chemical reactions and viscous dissipation impacts are also taken into account. The governing equations are converted into dimensionless ordinary differential equations (ODEs) using appropriate similarity transformations. The highly nonlinear ODEs are solved numerically by employing a shooting technique based on the Runge–Kutta Cash–Karp formula. The figures are used to study the variations in temperature, velocity, and concentration profiles for several physical factors. The numerical values of the local skin friction, Sherwood number, and Nusselt number are explained and shown in tables. The analysis reveals that the velocity profile is enhanced for amplifying values of velocity ratio parameter and first-order velocity slip parameter. However, the temperature profile of Jeffrey nanofluid is highlighted w.r.t. Eckert number and radiation absorption parameter. This study may find significant applications in polymer production, food processing, instrumentation, combustion modeling, catalytic chemical reactors, and so on.     

Mathematical modeling and study of MHD flow of Williamson nanofluid over a nonlinear stretching plate with activation energy

This study investigates the Williamson nanofluid flow through a nonlinear stretching plate. It aims to analze the global influence of Williamson parameter (λ) rather than local, which is researched for a linear stretching case in the literature. In addition, the features of activation energy are also taken into account in the current review. The developed model with the consequent similarity transformation has still not been perceived. The transformed partial differential equations are solved analytically. The consequences of embedded parameters on the velocity, temperature, and concentration profiles are displayed through figures. Also, the consequences of embedded parameters on skin friction, heat transfer, and mass transfer are demonstrated through tables.     

IEEE Power Engineering Review

This article highlights the significance for US Federal Energy Regulatory Commission (FERC) orders related to electric utilities, and explains their impact on the US electric utility industry. These orders are direct results of government-enacted laws and range from addressing issues of generator open access to transmission lines to the mitigation of restructuring electric utilities' stranded costs. A brief history and legal foundation of FERC is given, as well as an outline of the major tenets of the orders, which include 888 for open access, 889 for the Open Access Same Time Information System (OASIS), and 2000 for regional transmission organizations (RTO). This article includes the progression of these orders and some of the consequences arising from them, as well as their connectivity to the major Acts of Congress related to electric utility regulation and business structures. The contents of this article reflect the essential knowledge required of utility managers regarding the US government's utility regulatory system and the legal foundations that are shaping the development of electric utilities and the direction of management philosophies and practices.     

IEEE Power Engineering Review

Technology costs have come down hugely, and wind is now knocking at the door of coal, nuclear, and even gas as the least-cost energy source in developed countries. The UK has experienced wind farms that have put in bids under the Non-Fossil Fuel Obligation (NFFO) at about US$0.03/kWh, and this is probably a benchmark for many projects in the United States. Yet in many of the World Bank's client countries, which have good and in some cases outstanding wind regimes, costs are much higher, installed capacity is low, and the prospects are gloomy. The primary concern should be to build sustainable long-term markets in which wind can compete on a level playing field with the private sector undertaking most, if not all, of the construction, financing, operation, and maintenance of wind farms with their output being sold into the wholesale electricity market. That is what the World Bank is increasingly focusing on, a long way from old-fashioned lending for big lumps of infrastructure. They do this by working on policy and regulatory issues relating to renewables. Of particular importance is the introduction of mandated market schemes (renewables portfolio standards, systems benefit charges, and feed-in tariffs) accompanied market development measures to help support the growth of the market infrastructure.     

IEEE Power Engineering Review

China is a developing country. With the move towards deregulation and opening markets, there have been many changes in the industrial and technical sector, especially in the power industry. The changes penetrate into generation, transmission, and distribution systems. With development of the Three Gorges project started in the 1990s, many studies and test projects have been carried out to determine the type of transmission lines, automation devices, etc. The progress associated with the Three Gorges power system, compact lines, and distribution automation is summarized.     

IEEE Power Engineering Review

For more than a half-century after the struggle between AC and DC for universal production, transmission and utilization of electric energy had been dominated by AC. This position remained unchallenged until the 1950s. At that time, the availability of large, high-powered, mercury arc rectifiers gave birth to a new interest in the application of DC for transmission purposes. One of the primary drivers for this reawakening of interest was cost, the historical justification for many of the early high-voltage DC (HVDC) schemes. The benefits of HVDC are outlined. Examples from North America, South America, Scandinavia, India and China illustrate the successful and mutually beneficial partnership between hydroelectric generation and HVDC transmission.     

城市垃圾焚烧发电厂与污水处理厂结合建设的方案探讨

论述了城市垃圾发电厂与污水处理厂结合建设,以废治废,取长补短,相互利用,可节约投资,降低两者的运行成本,提出了垃圾电厂建设与污水处理厂结合的２种经济方案。图３表４参４     

IEEE Power Engineering Review

The natural gas and electric industries are currently undergoing the most fundamental transformation in nearly a century, moving from a heavily regulated monopoly structure to an industry based on competition and customer choice. In this paper, the author describes the distribution company (DISCO) of the Future Forum, which is an assembly of 50 industry leaders, and has focused on the challenges faced by electric and gas distribution utilities, the companies with wires and pipes to homes and businesses, under this new paradigm.     

热网管道的保温厚度与工质温度、保温材料导热系数的关系计算

在国家规定的热网管道的每米热损失下,其保温层厚度随着保温材料的导热系数及工质温度的不同而不同。利用导出的计算公式,通过计算,将以上四个参数的关系用图表的形式表示出来,以供在热网管道的保温中予以应用。     

Mixed convection in laminar film flow of a micropolar fluid

In this paper, the steady mixed convection boundary layer in laminar film flow of a micropolar fluid is considered. The resulting nonlinear coupled ordinary differential equations are solved numerically using an efficient implicit finite-difference scheme. The numerical results obtained for the skin friction coefficient and the local Nusselt number, as well as the velocity, angular velocity or microrotation and temperature profiles are presented in tables and figures for different values of the material parameter K and the Richardson number Ri when the Prandtl number Pr = 0.7 and Pr = 1.     

沼气电站工艺设计的研究

就沼气电站的工艺设计系统所涉及的特殊要求,从沼气电站设备选型及容量、沼气系统、通风系统、润滑油系统、冷却系统、排烟系统和机组起动及设备布置等方面进行了探讨研究,可为沼气电站工程的工艺设计提供参考;也可为建造其他燃气电站工程提供设计计算模式。     

Spectral simulation to investigate the effects of nanoparticle diameter and nanolayer on the ferrofluid flow over a slippery rotating disk in the presence of low oscillating magnetic field

This article explores the impacts of the solid–liquid interfacial layer and nanoparticle diameter on the unsteady ferrous-water nanoliquid flow over a spinning disk. The existence of velocity slip is presumed on the disk. Additionally, the low oscillating magnetic field effect is included to extract the hydrothermal consequences of the problem. Shliomis theory has been presented to verbalize the foremost equations of the mentioned flow problem. The similarity transformation renders the dimensionless equations. Spectral quasilinearization technique along with the residual error profile is presented to resolve the converted equations. An adequate number of pictures and tables are portrayed to improve the parametric study of the problem. Several streamlines, isotherms, contour plots, and three-dimensional figures are presented to disclose the hydrothermal integrity of the nanofluidic transport. Effective magnetization parameter produces 4.67% skin frictional increment. Heat transport declines for nanoparticle diameter but is enhanced for nanolayer conductivity ratio. The presence of an oscillating magnetic field always promotes heat transference as compared with the absence of the oscillating field. The nanolayer conductivity ratio conveys the highest 8.69% heat transport rate, whereas the magnetization factor provides the lowest, 1.79%. It has novel applications in magnetic drug targeting, hard disk scaling, magnetic resonance imaging, spin coating, lubrication, and so forth.     

IEEE Power Engineering Review

Of all power quality issues, voltage sags and short interruptions are considered to be the main cause of more than 80% of the problems experienced by sensitive equipment. Customers normally suffer from the effect of the induction-motor and supply-system interaction, and utilities can experience significant loss of load. The motor undervoltage protection could trip the motor contactor if the supply voltage stays too low for a long time. New power quality requirements have an important effect on the motor system interaction, for example, the increasingly popular motor fast reconnection to the same source or to an alternative source. The load characteristics during the reconnection instant are also critical for the motor behavior, since it is possible that the motor would stall and not start when the supply voltage is restored. This article documents an experimental study that is the first part of an extensive project with the goal of developing a simple tool for the study of induction motor behavior and system effects under short interruption and voltage sag conditions.     

IEEE Power Engineering Soceety

The North American Electric Reliability Council Report, 1989 Reliability Assessment, summarized. Reliability in a bulk electric system is defined, and the need for reliability criteria is discussed. The consequences of inadequate reliability are examined. Some major electric system disturbances are described, the socioeconomic impacts of electric power supply interruptions are considered, and emergency operating procedures are discussed. Peak demand projections are given.<>     

IEEE Power Engineering Review

The electric utility industry in North America is undergoing a transformation unlike anything it has experienced in its history. Disassembly of the traditional vertically integrated utility is taking form in response to pressures to privatize, customer choice demands, competition in the marketplace, improved quality of service, and unfettered access to the transmission network. How will restructuring affect the reliability and quality of our electric power service? Today's world offers the electric utility industry a difficult but exciting challenge to organize itself so that utilities can compete in an open market for customer allegiance, while at the same time preserving a reputation for delivering a reliable, high quality service. Obviously, if reliability and quality standards are not met, the customer base will erode and perhaps disappear, which is an untenable situation. Similarly, if the utilities' commercial interests in the new marketplace are not maximized, company earnings can be placed in jeopardy. However, we have not embarked on this restructuring of the industry to put utilities out of business. We must find the middle ground that ensures we deliver a quality service over a secure transmission network at the best possible price for customers and a fair return to shareholders.     

IEEE Power Engineering Review

France appears to have the second largest wind energy potential in Europe, after the United Kingdom. According to certain estimates the potential annual production is evaluated at 70 TWh on the land and more than 90 TWh for offshore sites located in an area along the coast, with a maximum width of 10 km and where the sea depth is less than 10 m. This potential production of more than 160 TWh represents approximately 33% of the present electricity generation in France. However, the wind energy potential that will actually be exploitable will be noticeably lower. This paper describes the EOLE 2005 Program, a French national program for the promotion of wind power, launched in February 1996. The targets and incentive measures for wind power development are discussed. The grid connection of wind farms and offshore wind energy are also discussed.     

IEEE Power Engineering Review

This article provided three themes found in the development of electric utility related laws: laws enacted to change electric utility business practices have been based on historical events of the time, with a view toward providing more stability in business and consumer sectors; laws to date have not been comprehensive in deference to the rights of individual states to determine the business structure and operations of electric utilities within their legal jurisdiction; and in general, new laws that have been enacted tend to carry the best elements of the previous laws, while attempting to provide more relevancy according to the historical needs of the time. This provides an incremental, circular advancement of legal landmarks establishing guidelines for electric utility businesses and consumer interactions. With the advent of utility deregulation and the move towards enabling competition, this process has culminated in calls for a more comprehensive, federal legal structure in the United States. This is because of the changing nature of wholesale and retail power sales and purchases that are increasingly traveling beyond the political boundaries of states, and are more inclined to follow a regional, market-based grid formation. New enactments must be rooted in the most effective provisions found in existing legislation, such as wise business practice regulation and promotion of competition and environmental safeguards.