JAGR - Journal of Applied Global Research

Volume: 5, Issue: 13

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• A UNIFIED METHOD FOR COAL-FIRED POWER PLANT PERFORMANCE MONITORING
  Author(s): Sastry Munukutla
  

A UNIFIED METHOD FOR COAL-FIRED POWER PLANT PERFORMANCE MONITORING

Author(s): Sastry Munukutla

Greenhouse gas (GHG) emissions from coal-fired power plants are major contributors to global warming. Several technologies that lead to emissions control and carbon sequestration are being developed to mitigate GHG effects. While there is considerable success much remains to be done. Meanwhile a straightforward method of reducing GHG emissions is to improve the efficiency of existing coal-fired units. Improved efficiency results in the consumption of less fuel for a given generation thus leading to reduced CHG emissions. Before attempting to improve the efficiency the performance needs to be monitored in real-time. Several commercial softwares are available for performance monitoring in real-time. Unfortunately none of these are true real-time methods since they all input a constant value for the coal heating value in spite of the fact that coal composition and heating value vary considerably during operation. In addition to this the definition of boiler efficiency is not the same in each of the commercial software. A unified method of performance evaluation with a consistent set of definitions for boiler efficiency, steam-cycle efficiency and finally the overall unit efficiency is, therefore, needed. In addition the coal-heating value needs to be calculated in real-time. Such a method, known as the output/loss method has been researched thoroughly for the last 25 years at Tennessee Tech University. A software based on this method has been successfully installed in 10 coal-fired units in the USA, four units in New Zealand, one unit in China and one unit in India. In this paper the thermodynamic model with which the output/loss calculations are done will be discussed. Field results from several units around the world will be presented. Finally strategies for performance improvement based on real-time performance monitoring will be discussed.

Keywords: Coal-Fired Power Plant, Boiler Efficiency, Steam Cycle Heatrate, Unit Heatrate, Output/Loss Method, Thermodynamic Model.



• TRANSIENT PERFORMANCE OF A CROSS FLOW HEAT EXCHANGER SUBJECTED TO SEVERAL CHANGES IN THE INLET TEMPERATURE
  Author(s): Karthik Silaipillayarputhur and Stephen A. Idem
  

TRANSIENT PERFORMANCE OF A CROSS FLOW HEAT EXCHANGER SUBJECTED TO SEVERAL CHANGES IN THE INLET TEMPERATURE

Author(s): Karthik Silaipillayarputhur and Stephen A. Idem

A thorough understanding of transient response in heat exchangers due to changes in inlet fluid temperatures is extremely critical in sensitive process applications such as power plants and chemical process plants. This paper initially discusses the development of transient sensible performance model of a cross flow heat exchanger. Thereafter, the transient performance of a single pass, single row, and unmixed cross flow heat exchanger, subjected to several changes in the inlet temperature of the minimum capacity rate fluid was considered. Sudden step change, successive step changes, quasi-sinusoidal change, sinusoidal change, and steady ramp change in the inlet temperature of the minimum capacity rate fluid were considered. An implicit central finite difference method was used to solve the transient case. A detailed study was preformed by analyzing the transient responses of the heat exchanger subjected to several changes in the inlet temperature of the minimum capacity rate fluid.

Keywords: Transient Performance of a Single Pass Cross Flow Heat Exchanger, Heat Exchanger Modeling Using Implicit Central Finite Difference Method, Transient Performance of a Heat Exchanger Due to Inlet Temperature Variations.



• INVESTIGATION OF CUTTING FORCES DURING TURNING OF EN31 STEEL USING CRYOGENATED AND UNCRYOGENATED TUNGSTEN CARBIDE INSERTS
  Author(s): Suresh Dhiman, Vikash Kondal, Shivam Puri and Ravinder Kumar
  

INVESTIGATION OF CUTTING FORCES DURING TURNING OF EN31 STEEL USING CRYOGENATED AND UNCRYOGENATED TUNGSTEN CARBIDE INSERTS

Author(s): Suresh Dhiman, Vikash Kondal, Shivam Puri and Ravinder Kumar

In the present study, Tungsten carbide inserts were subjected to shallow cryogenic treatment of sub zero temperature (-120°C). Machining studies were conducted on EN31 steel having hardness 37HRC using untreated and shallow cryogenic treated tungsten carbide cutting tool inserts under dry cutting conditions. Input cutting parameters such as speed, feed, approaching angle (a geometric variable) were changed while the depth of cut and rake angle were kept constant. Output variable such as Cutting force & Thrust force were measured using 5-Components lathe tool dynamometer at various combinations of speed, feed and approaching angle. Comparisons were made for force components with different cutting parameters and tool geometry using cryogenated and uncryogenated tool. The cutting force components exhibited lower trend while machining EN31 Steel with cryogenic treated carbide tools. Keywords: Cutting Forces, Machining, Approaching Angle and Cutting Parameters, Cryogenic Treatment.



• THE DEVELOPMENT OF A CONCEPTUAL MODEL FOR COLLISION DETECTION AND AVOIDANCE FOR RUNWAY INCURSION PREVENTION - A CASE STUDY FOR AIR TRAFFIC CONTROL
  Author(s): Bridgette Latimer and LeeRoy Bronner
  

THE DEVELOPMENT OF A CONCEPTUAL MODEL FOR COLLISION DETECTION AND AVOIDANCE FOR RUNWAY INCURSION PREVENTION - A CASE STUDY FOR AIR TRAFFIC CONTROL

Author(s): Bridgette Latimer and LeeRoy Bronner

The Federal Aviation Administration (FAA), National Transportation and Safety Board (NTSB), National Aeronautics and Space Administration (NASA), numerous corporate entities, and research facilities have each come together to determine ways to make air travel safer and more efficient. These efforts have resulted in the development of a concept known as the Next Generation (Next Gen) of Aircraft or Next Gen. The Next Gen initiatives require that modifications are made to the existing National Airspace System (NAS) concept of operations and system level requirements. An example of one of the changes in the NAS is the shift away from air traffic controllers having the responsibility for separation assurance. In the proposed new scheme of free flight, each aircraft would be responsible for assuring that it is safely separated from surrounding aircraft. The primary goal of this research effort was to create a conceptual model that embodies the essential elements needed for a collision detection and avoidance system in support of Next Gen. This system was required to operate in two modes: air traffic controller's perspective and pilot's perspective. The secondary goal was to demonstrate that the technologies, procedures, and decision logic embedded in the conceptual model were able to effectively detect and avoid collision risks from both perspectives. Embodied in the conceptual model are five distinct software modules: Data Acquisition, State Processor, Projection, Collision Detection, and Alerting and Resolution. The conceptual model was created using Enterprise Architect® and MATLAB® was used to code the methods and simulate conflict scenarios.

Keywords: Collision Detection and Avoidance, Air Traffic Control, Next Generation of Aircraft, Federal Aviation Administration, Object Oriented Analysis and Design, Separation Assurance, and Enterprise Architect®.



• INFORMATION SEARCH FOR MEDICAL TREATMENT ABROAD
  Author(s): Anita Medhekar and Leonce Newby
  

INFORMATION SEARCH FOR MEDICAL TREATMENT ABROAD

Author(s): Anita Medhekar and Leonce Newby

Medical tourism is one of the fastest growing health service sectors where consumers as medical tourists use a variety of sources of information such as family, friends, previous personal experience, print and media, general practitioners (GP) and Internet to explore and find information about their decision to travel abroad to countries or destinations such as Thailand, India, Dubai, Mexico, Venezuela or Poland for medical treatment. It is widely acknowledged that there is a vast collection of health and medical tourism related information available on the internet as various countries and hospitals are offering complex state-of-the-art invasive surgeries and non-invasive treatments. However, the information is of variable quality and therefore the search cost, time and information search skills of medical consumers are important in the selection and assessment processes utilised to obtain this information about the medical treatment, physician, hospital, and destination best suited to their health and medical related travel purposes. The way consumers search, choose, evaluate and appraise information regarding their choice of medical tourism destination - country, hospital and doctor - is important, because all these sources of information on health and medical tourism can influence a consumer's decision to travel, or not to travel overseas for medical treatment to improve their health and well-being. The objective of this empirical paper is to use qualitative methodology to investigate medical tourists as consumers of the medical tourism healthcare product and services by researching their experiences in searching for and appraising various sources of information on the decision to travel overseas for medical treatment. Data will be analysed to support the development of an information search model of medical treatment abroad. The research findings, managerial implications and conclusions will be discussed.

Keywords: Medical Tourist, Medical Treatment Abroad, Information Search, Qualitative Research.