Keywords: ASME B 31.3, Stress intensification factor (SIF), CAESAR II, Code compliance, Piping code.

Transcription

1 Volume 119 No , ISSN: (on-line version) url: ijpam.eu Stress Analysis of Power Piping from Auxiliary Steam Piping to Air heater Soot Blowing S.Aathresh T.Madan kumar V.Velmurugan Department of Mechanical, Saveetha school of Engineering, Thandalam, Chennai. ABSTRACT The most appropriate method to check whether the process is running in safe and economic condition is by product analysis. This method contributes the best possible conditions showing that the work carried are up to the permissible limits issued by the department of safety conditions. Hence a process plant is regulated safely and effectively only through a safe piping system. The piping parameters play a significant role in the effectiveness and efficiency of a process plant. Design of piping parameters include pipe fitting, thickness, equipment layout, size calculations, support type, pipe routing, location and mainly pipe line traversing and stress analysis Pipes are installed in an industry to carry out the necessary fluids from one place to another. The designing and construction of piping systems in any plant are expensive and time consuming and complex effort. Each piping code specifically denotes the work and applications of the piping system used in a plant. The basic piping code used in this paper is ASME B The objective of this paper is to show that the piping design of Auxiliary steam piping to Air heater soot blowing are according to piping code and in safe conditions so that the design is optimum in condition. However the piping design is done in CAESAR II software and static analysis is carried out in order to find out code compliance stresses, elemental forces, displacement at all nodes, sorted code stress, moments in coordinates in the piping layout. By comparing the SIF results against the software depicted results are according to the safe running conditions. Keywords: ASME B 31.3, Stress intensification factor (SIF), CAESAR II, Code compliance, Piping code. 1.INTRODUCTION 15791

2 Pipe design mainly depends upon stress analysis. The main objective of pipe stress engineer is to verify the routers, hangers and supports are placed correctly in the process plant and the allowed pipe stress is not to exceed by various loads acting along the piping system specified by ASME B31 conditions and standards. Mechanical behavior of pipes is strictly evaluated under various loading conditions. CAESAR II: Computer Aided Engineering Stress Analysis and Routing is a complete software related to pipe stress analysis developed by INTEGRAPH corporation used to calculate and measure quick analysis of piping system that is bullied to weight, pressure, thermal, seismic and static and dynamic loading resulting from the effects of gravity, temperature changes, internal and external pressures, changes in fluid conveyance flow rate and seismic activity. CAESAR II is unique in incorporating calculation methods and analysis option. It provides static and dynamic analysis of piping systems. This paper deals with the reference of stress analysis in a process piping determined by the software used upon their respective application. Many pipe stress analyzing programmes are available in the market and their usage depends upon the field they are utilized. The most widely used software in the field of pipe stress is PDMS, CAEPIPE, CAESAR II. A pipe is modeled as several elements connected to a common nodal point. Then the appropriate loads are applied and using boundary conditions the problem is solved using finite modern element approach. C. Basavaraju[1] has carried out an immense work on Stress analysis of piping systems highlighting the scope of piping systems, supports, materials, fittings, insulation, operating medium in a pipe line & Finite analysis of main stream in pipe line. Hence his parametric study is helpful for calculating the involved stresses and problems in a piping system. G.M. Pradeep [2] objectified his paper on Analysis of thermal flexibility in an expansion loop using CAESAR software. This work concluded that installation of piping loops is the best possible way to increase the piping system flexibility. Shweta Bisht & Farheen Jahan [3] has explained the need of Design of piping system in the world of fluid conveyance and concluded that stress analysis is a critical component of piping design through which important parameters such as piping safety, safety of related components and connected equipment and piping deflection can be checked and rectified timely. M.Jamuna Rani& K.Ramanathan[4] has done the analytical study of piping system using CAESER software and concluded that displacement in the piping system of expansion joint is comparatively lower than piping system with hangers.bahaa Shehadeh, Shivakumar Ranganathan & Farid H Abed[5] et.al carried a work on expansion loop in a piping system to determine the loads and stresses are acted in a piping system. Payal Sharma Ȧ, Mohit Tiwari Ȧ & Kamal Sharma A[6] et.al carried a work on Design and Analysis of a Process Plant Piping System and suggested different ways of stress calculations for a stress load and flexibility of a expansion loop and analysis of it using CAESER II. D. M. Awze, A. K. Mahalle [7] et.al proposed a method titled comparative analysis analysis of different piping configurations for piping flexibility[8] by comparision analysis using FEA technique. 2. EXPERIMENTAL PLAN In the course of process pipeline it encounters many system parameters including stress, load variation, flexibility, structure, buckling and many more. An engineer has to encounter these conflicts in order to maintain an effective environment in the industry. The main cause for economical deficiency in a process plant is due to the applied stresses on the piping routers. It is 15792

3 difficult to any maintenance engineer to cross check all these variations, hence many piping software were developed. These suggest the best piping parameters for the applied load on a piping system. Economical analysis of a chemical plant in recent studies shows the major pipe loss factors are due to even stress and load acting on them. Therefore attention is focused towards the attainment of flexibility and optimization of piping layouts in their applications of process piping. Standardization of piping layout can reduce cost, inconvenience and unrelated disturbances in the routers. Hence optimization techniques like installation of expansion loops, hanger supports, anchors are encouraged. These evaluations include pipe moments, anchorage force, soil friction, lateral soil and environment pipe interaction. In these existing methodologies proposing the concept of pipe stress analysis leads to a new way invention regarding better optimization techniques in CAESAR II software. This commercial data software is used in process industries to gain significant savings in plant ergonomics. Therefore an existing profound concept of analyzing auxiliary steam in a piping system is emphasized. Auxiliary steam is used in power plant section for various process applications like sooth blowing and in mill pulverizing. A pipe suffers significant amount of stress and sometimes leads to failure of plant. Hence CAESAR II software is used to calculate stress analysis acting on the pipe line carrying auxiliary steam. This software obtained result concludes the optimization techniques to be followed in the optimization of layout for this process. A layout is designed in the software and analysis is done for the process piping system. This study gives the safe routing parameters for designing the piping layout from Auxiliary Steam Piping to Air heater Soot Blowing. 2.1 Input data for stress analysis The following figure 2.1 illustrates the piping input parameters for stress analysis done in CAESER ii software. Figure 2.1 Input data parameters 15793

4 2.2 Input Data The following Table.1illustrates about the input parameters of piping layout done in CAESER II Software. Diameter Thickness Table.1Input parameters of piping layout 168mm 7mm Pipe material SA 106 grade B Density of pipe material kg/cu m. Temperature Pressure Type of Fluid Insulation Thickness Fluid density 210 deg C 20 kg/cm2 Saturated Fluid 95mm kg/cm3 2.3 Design of piping layout A piping layout is designed using CAESAR II software in the boiler section for application of soot blowing. The figure illustrates the isometric view of piping layout given by NTPC( National Thermal Power Corporation). Figure Isometric view of piping layout The figure illustrates the isometric piping layout and it is done in CASER II Software

5 Figure Model of piping layout A pipe engineer has to cross check all the included parameters in designing the piping layout for the power plant. Certain optimization techniques are used in designing the layout by considering the plant economics and safety. These steps may increase the plant life and efficiency of the boiler in the power plant. Figure illustrates that the model is done in AUTOCAD Software and the yellow line in figure shows the required piping layout. 3. RESULTS AND DISCUSSION 3.1 Stress Analysis as Per Code ASME B31.3 Figure Yellow line showing the pipe layout Code ASME Stands For American Standard For Mechanical Engineering And B31.3 Code Stands For Analysis.Results are obtained using CASER Software as shown in figure From the values,it is concluded that the stress acting on piping system are in safe condition

6 Figure stress acting at different loading conditions 3.2 Global distribution of forces and moments in different load conditions At Node 10 From the Table.2 various loads are acting at node 10 and the values obtained in the table.2 are in permissible limit. Table.2 Restrain summary at node 10 RESTRAINT SUMMARY REPORT : Loads On Restraints Various Load Cases LOAD CASE DEFINITION KEY 15796

7 Restrain Forces and Moments International Journal of Pure and Applied Mathematics CASE(OPE) W+T1+P1+H CASE(SUS) W+P1+H CASE(EXP) L7=L4-L6 NODE LOAD FX N. FY N. FZ N. MX MY MZ CASE N.m. N.m N.m 10 RIGID ANC 4(OPE) (SUS) (EXP) MAX -236/L -1710/L 1814/L 4423/L 842/L 1570/L From the graph various load are acting at node 10 and the Figure illustrates about the Distribution of forces and moments at node10 and the values obtained are in permissible limit GraphicalAnalysis of Forces &Displacements in all Load cases At Node 10 DISTRIBUTION OF FORCES AND MOMENTS DISTRIBUTIO N O F FO RCES AND MOMENTS (OPE) (SUS) 0 7(EXP) MAX AT NO DE 10:: RIGID ANCHOR SUPPORT Figure Restrain analaysis at Node 10 The above graph states that stress limit in the designed pipe line is upto the permissible limit

8 MOMENTS AIN FORCES AND International Journal of Pure and Applied Mathematics 3.3 Global distribution of forces and moments in different load conditions : At Node 410 From the Table.3 various loads are acting at node 410 and the values obtained in the table.3 are in permissible limit. Table.3 Restrain summary at node 410 RESTRAINT SUMMARY REPORT : Loads On Restraints Various Load Cases LOAD CASE DEFINITION KEY CASE(OPE) W+T1+P1+H CASE(SUS) W+P1+H CASE(EXP) L7=L4-L6 NODE LOAD FX N. FY N. FZ N. MX MY MZ CASE N.m. N.m N.m 410 RIGID ANC 4(OPE) (SUS) (EXP) MAX -137/L -1479/L -71/L -989/L 429/L 315/L From the graph various load are acting at node 410 and the Figure illustrates about the Distribution of forces and moments at node 410 and the values obtained are in permissible limit 3.3Graphical Analysis of Forces &Displacements in all Load cases At Node 410 Distribution of forces and moments 5000 OPE 0 SUS EXP AT NODE 410:: RIGID ANCHOR MAXSUPPO Figure3.3.1.Restrain analaysis at node

9 The above results and graphs states that the stress limit in the designed pipe line is up to the permissible limit and the design can be considered for the installation of the pipe line design in the boiler section of power plant. 4. CONCLUSION Analysis of piping layout is wide spread concept and it is gaining importance all around the corner. It is important for an engineer to calculate all the implied stress and load factors to ensure that the plant is working is working in safe operating conditions. These optimization techniques calls for pipe savings and leads to cost efficient process plant. In order to save material costs various techniques are employed like installation for new equipments, analyzing the material, modeling new process plant layout etc. Results indicate that by following these standardized techniques increases plant life and also lead to positive quality management. This environment provides the ability to iterate the layout easily and saves time by reducing the time of consta nt inspections. In sustained condition, the displacement, stress and code compliance reports as per ASME B31.3 were analyzed and its values were tabulated. In expansion condition, the displacement, stress and code compliance reports as per ASME B31.3 were analyzed and its values were tabulated. Since the sustained and expansion stress values are less than the allowable stress values as per ASME The process pipe routing was accepted. 5. REFERENCES [1] C Basavaraju, Stress Analysis of Piping Systems, 2004, Published by McGraw Hill, pp. B107-B120 [2] G.M. Pradeed, STRESS ANALYSIS OF PROCESS PIPING USING CAESAR II IJRME- International journal of research in Mechanical Engineering,2016,volume: 03 ISSN: [3] AN OVERVIEW ON PIPE DESIGN USING CAESAR II Shwetha Bisht and Farheen jahan International Journal on Emerging Technologies, ISSN: [4] M. Jamuna Rani, K. Ramanathan,Design and Analysis of Piping System with Supports Using CAESAR-II, 2016,Vol:10, No:5 [5] OPTIMIZATION OF PIPING EXPANSION LOOPS Bahaa Shehadeh,shivakumar Ranganathan & Farid H abed, 2016, Vol. 230(1) [6]FLEXIBILITY AND STRESS ANALYSIS OF PIPING SYSTEM USING CAESAR II Prachi N Tambe International Journal of Engineering Research & Technology (IJERT) ISSN: [7] ] D. M. Awze, A. K. Mahalle Design of Steam Pipe Layout and HangerSupport in Thermal Power Station International Journal of RecentTechnology and Engineering (IJRTE), May 2013.ISSN: ,Volume-2,Issue-2 [8] A.Ramya, 2L.Kalaiselvi A HIGH THROUGHPUT FPGA BASED ARCHITECTURE FOR REAL TIME EDGE AND CORNER DETECTION International Journal of Innovations in Scientific and Engineering Research (IJISER) 15799

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