DESIGN OF A MICRO-HYDRO TURBINE TEST RIG EML –4905 SENIOR DESIGN PROJECT77 Table 15: Results from Strain Analysis on StructureName Type Min Location Max Location Strain1 ESTRN: Equivalent Strain 4.97587e-012 Node: 305979 (-3.54694 in, -0.868137 in, -77.4678 in) 0.000607946 Node: 272713 (36.6869 in, 94.7573 in, -0.748237 in) Figure 35:Strain Analysis of Structure
DESIGN OF A MICRO-HYDRO TURBINE TEST RIG EML –4905 SENIOR DESIGN PROJECT78 Figure 36:Design Check Analysis (FOS) The above figures show the results from the simulation trials if a force was to be exerted on the top members of the structure. From these results it can be seen that the structure has a relatively high safety factor and that if the tank were to be filled completely with water, the maximum displacement of the structure will be 1.54mm. This shows that the structure is well suited to the application at hand.
DESIGN OF A MICRO-HYDRO TURBINE TEST RIG EML –4905 SENIOR DESIGN PROJECT79 5.4 Material Selection Material was selected according to availability always ensuring to surpass the requirements for the design. The most critical material for the design was the one for the piping. PVC schedule 40 was selected as it exceeds the expected maximum pressure for both systems setups dictated by the pump performance curve. According to standard ASTM D2466-06 namely “Standard Specification for Poly (Vinyl Chloride) (PVC) Plastic Pipe Fittings, Schedule 40, the pipes used in this design have an operating pressure of over 100 psi. The most critical pipe section is the 4” diameter pipe with a pressure rating of 133psi. Related materials for the piping system included, cleaner, primer and cement, all of which have the proper certifications and are well known for these types of applications. The hoses included in the design were suction hoses exceeding the demands for this design and having strong characteristics very similar to the pipe itself. Threaded ends ensured a proper fit with minimal leakage. In order to have proper instrumentation, it was decided to buy brand new flowmeters in order to avoid calibration issues with the available electro-magnetical flowmeter which have not been properly maintained.
DESIGN OF A MICRO-HYDRO TURBINE TEST RIG EML –4905 SENIOR DESIGN PROJECT80 6. Prototype Construction 6.1 Description of Prototype The prototype was design under the requirements that it must be able to simulate the conditions for two general types of micro hydro-turbines, action and reaction turbines. The problem to overcome is the difference in these conditions which are volumetric flow of water and the pressure head at which the water is discharged to the turbine. For the action turbines to be tested in the rig, it should produce a high head discharge in order to work properly. On the other hand the reaction turbine needs a high flow rather than a high pressure discharge. Another basic problem to overcome is the pressure condition under which the turbines work. The action turbine needs to work under atmospheric pressure and the reaction turbine must be immersed in water followed by a draft tube that will connect the water line to the pumps to draw the water downstream.
- Fall '08
- Mechanical Engineering, ........., Senior Design Project, Turbine Test Rig