Design and Operation of Sustainable Systems | My Assignment Tutor

Academic Year 2020/21Examination Period: 2021 May ExamModule Code: MP4701Module CRN: 37227Exam Type: WrittenModule Title: Design and Operation of Sustainable SystemsModule Leader: Dr. Geng Feng Examination Paper StructureThis examination paper has 4 questions in total.All questions carry equal marks of 25 marks.Students to be provided with:NoneInstructions to Students:The time allowed to complete this examination paper is 24 hrsAnswer all Four questions. Each question worth 25 marks. Total exam is out of 100marksPlease note, that no marks will be awarded for answers that are copied and pasteddirectly from elsewhere. Question 1: Condition Monitoring (25 marks)a) What are the main steps in the generic procedure for implementing a condition monitoringprogramme which are outlined in BS ISO 17359:2011?(5 marks)b) Answer the following about condition monitoring techniques, according to your experienceduring the module: 1-With the aid of a block diagram, outline the main elements of the vibration analysissystem(2 marks)2-Name two vibration analysis methods used to analysis vibration signals.(2 marks)3-For the given accelerometer response (shown in Figure Q1.1):i.ii.At what approximate frequency does attenuation occur?What approximate frequency does resonance occur? Figure Q1.1 (2 marks)4- Name two sources of AE signal in machinery condition monitoring, and the correspondingAE signal types.(2 marks)5- Name two approaches used in oil debris analysis.(2 marks)c) For the gearbox (shown in Figure Q1.2), use the BS ISO 13373-3 standard (Equations providedin Appendix A) to calculate the expected defect frequencies of bearings no. 6, if the inputshaft speed is 6000rpm.(6 marks)Given:Gearbox Data: Type: Reduction Helical Gearbox.No. of stages: 2Bearings data: All bearings shown in Figure Q1.2 and Figure Q1.3 are cylindrical roller bearingsand of the same type and have the data provided in Table Q1. StageNumber of teethFigure Q1.2, source www.skf.com1stGear A: 21Gear B: 682ndGear C: 30Gear D: 48 Table Q1: Bearing dimensionsd) For Gear A in the helical gearbox shown in Figure Q1.2, calculate the expected gearfundamental frequencies, if the input shaft speed is 6000 rpm.(4 marks)TOTAL 25 marks ParametermmFigure Q1.3, source www.skf.comOuter diameter62Inner diameter25Pitch diameter of rollers (P)44Diameter of roller (B)8Number of rollers (N)10Contact angle (Ø)0 Appendix A (Q1)Question 2: Qualitative Systems Reliability Analysis (25 marks)a) HAZOP and FTA are two key concepts to perform system reliability analysis.(i) Identify the acronyms HAZOP and FTA.(ii) State the advantages and limitations of FTA with examples.(4 marks)b) The drivetrain of a wind turbine is composed of the gearbox and the generator, thenecessary components that a turbine needs to produce electricity. Figure Q2 below showsthe cut-away view of a typical wind turbine drivetrain.State two design for reliability principles according to British Standard and how they could beapplied to the wind turbine drivetrain design.Figure Q2. A typical wind turbine drivetrain(6 marks)c) Perform an indicative 3-level system break down describing the wind turbine system,identify ONLY 4 failure modes (at least two different modes for one component) and performFMECA to prioritise risks. Justify the differences between FMEA and FMECA.(15 marks)TOTAL 25 marksQuestion 3: Quantitative System Reliability Analysisa) Figure Q3.1 shows a Reliability Block Diagram with several components in series andparallel. Components B1, B2 and B3 are identical and operate all the time. Only one of thethree components is required to be operational for the triplex sub- system to operate. Henceit is referred to as a “1 out of 3” system.Calculate the overall system reliability at T = 1500 hrs using the data in Table Q3 and discussyour results[Hint] Which part of the system influences the overall reliability most?Figure Q3.1 Reliability Block DiagramTable Q3 – Data for Figure Q3(13 marks)b) Explain the significance of parallel configuration for three operating components B1, B2and B3 mounted in parallel, when a sub-system (yellow in Figure Q3.1) still operate withone component running when two others are not in operation.(2 marks)c) Using an appropriate method, calculate the reliability of the Reliability Block Diagram shown inFigure Q3.2. Show all steps of your working, and assume the reliability of each component is 0.97.Figure Q3.2: A system with five components(10 marks)TOTAL 25 marksQuestion 4: Bearings and Lubrication (25 marks)a) A hard steel cone having a semi-angle of 85° is drawn across the surface of a soft bronzeand aluminium plate by the mechanism of deformation due to ploughing. The bronze platehas a hardness of 900 MPa while the aluminium plate has a hardness of 600 MPa, and thenormal load is constant at 40 N. Estimate the width of the scratch, coefficient of friction andthe volume of material displaced in unit sliding distance for both the materials. Justify youranswer with supporting evidence?(5 marks)b) CASE STUDY ANALYSISCritically assess the outputs, techniques and reported surface treatments, failures on the casestudy (600 words maximum for the case study part):1. Ceramic Top Coats of Plasma-Sprayed Thermal Barrier Coatings: Materials,Processes, and Properties, Bakan, E., Vaßen, R. J Therm Spray Tech 26, 992–1010 (2017). marks)2. With the aid of diagrams, illustrate the case study surface treatment technique howit can be used to increase the life of the cylindrical roller bearings and briefly describe theadvantages and disadvantages of the techniques with respect to the tribological application,mechanical properties and life of the components.(5 marks)[Hint]: In order to do this task successfully, you will need to read other case studies from thesame journal and from books and investigate the surface treatment techniques, structuresand failures named in the articles but not explained, as it is assumed the reader already knowsabout them. You are asked to compare the relevant surface treatment process and brieflydescribe the advantages and disadvantages of the techniques with respect to the tribologicalapplication, mechanical properties and life of the components. Is there any other techniquecould have been considered not currently included in the article? What could have been thebenefit? Why do you think those techniques have been used in the article? Use references,examples and/or your own experience appropriately.c) SKF Bearings Limited Company is interested in studying the pin-on-disc sliding wear test fortwo different material pairs (Steel on brass and steel on aluminium tribo-pairs). A brassannulus and aluminium annulus having an outside diameter of 50 mm and an inside diameterof 40 mm is placed with its flat face resting on a smooth steel plate under a normal load of200 N and rotated about its axis at 6 Hz for 40 hours. At the end of the wear test, thespecimens were removed individually from the test rig and weighed using a precision balance.The weight loss of the brass and steel are 450 mg and 15 mg respectively. The weight loss ofthe aluminium and steel are 550 mg and 18 mg respectively. Using the materials data givenbelow, calculate wear coefficients for the two tribo-pair materials. Is brass or aluminium agood material to slide against steel? Support your justification with evidence?Hardness of steel: 2400 MPaHardness of brass: 900 MPaHardness of aluminium: 600 MPaDensity of steel: 7800 kg/m3Density of brass: 8700 kg/m3Density of aluminium: 2700 kg/m3(10 marks)TOTAL: 25 marksEND OF PAPER———————————


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