450 likes | 957 Views
School of Mechanical Engineering Level IV Design Project Seminar 2008 Project 629: Design & Build of a Vortex Heat Generator Bryan Gui Janice Kwok Phillip Lemon Supervised by Dr. Maziar Arjomandi. Sequence of Presentation. Janice. Janice. Bryan. introduction. feasibility. design.
E N D
School of Mechanical Engineering Level IV Design Project Seminar 2008 Project 629: Design & Build of a Vortex Heat Generator Bryan Gui Janice Kwok Phillip Lemon Supervised by Dr. Maziar Arjomandi
Sequence of Presentation Janice Janice Bryan introduction feasibility design Phillip Phillip Phillip conclusion management experimentation
Project Goals Design and manufacture a vortex heat generator and an experimental system Analyse performance of vortex heat generator Project Goals
Ranque-Hilsch Vortex Tube Air at 20oC Tangential inlet Air at 120oC* Hotter outflow Air at - 40oC* Cooler outflow Annular outlet *Typical values from Arizona Vortex Tube Mfg. Co.
Vortex Heat Generator Water Tangential inlet Warm outflow Hotter outflow Annular outlet
Significance RHVT potentially provides alternative heating source with: • No moving parts • Potentially high efficiency • Heat generated within fluid • Lower potential for fouling • Various domestic and industrial applications
Vortex Heat Generator feasibility study
Similar Devices Vortex Tube Noteka Vortex Thermal Generator Griggs Hydrosonic Pump Ref: AiRTX International (2008) Ref: Noteka (2004) Ref: Hydro Dynamics (2007)
Potential Heating Mechanisms • Friction / Turbulent dissipation • Chemical / Nuclear reaction • (Ref: Potapov et al, 1990) • Thermal separation • (Ref: Balmer, 1988) • Cavitation • (Ref: Savchenko et al, 1991)
Hydrodynamic Cavitation Factors Affecting Cavitation Typical Examples Geometry Pressure drop Velocity Surface roughness Nucleation sites Viscosity Turbines Ship propellers Hydrofoils Valves Bends Formation of bubbles when local pressure drops to vapour pressure
Bubble Life Cycle Nucleation Expansion P∞ < PV Collapse P∞ > PV Rebound
Cavitation in RHVT Vortex Cavitation Sharp edge Ref: Arndt (1981) Pressure Drop Within Flow Cone Sharp Edge Ref: Young (1989)
Vortex Heat Generator design
Design Systems RHVT Experimental Setup Circulation System Instrumentation
Ranque-Hilsch Vortex Tube Vortex Generator Body Bottom Outlet Inlet Top Outlet Return Line Outlet
Vortex Generator • Tangential Inlet • Water inlet at high velocity • Generates vortex
Vortex Generator • Cone • Creates narrowing annular passage • Increases velocity, lowers pressure • Designed to promote cavitation Increasing velocity
Bottom Outlet • Annular Outlet • Exit of outer flow • Outlet area is variable • Variable position
Circulation System RHVT system • Supply necessary inlet flow • Recycle water • Support RHVT and instruments • Mobile Pipes Valve Pump Frame Castors Tank
Submersible pump Easier efficiency measurement Higher pressure Pump Selection Submersible pump Non-submersible pump Grundfos SPO 5-70
Instrumentation Performance measures Required measurements Temperature increase, ΔT Heat output, E Heating efficiency, η Temperature, T Pressure, p Flow rate, Q Pump input power, P
Measurement Locations T P T T Vortex tube T P Flowmeter Submersible pump Data Logger Water tank T Pressure measurement P To mains Temperature measurement T Power Measurement
Instrument Fitting • Four taps to obtain average pressure • Modular design T-type thermocouple Pressure tap fittings
Manufacturing Processes Frame construction Fabrication of parts Welding/threading of connections Assembly Issues Misalignment/Offset Time
Vortex Heat Generator experimentation
Experimentation Aims Aims Can the RHVT heat water? Parametric investigation of RHVT performance Qualitatively investigate causes of heating • Cone • Tube length • Bottom outlet diameter • Water flow rate
Added weights to float to extend measurement range No calibration curve, calibrated against another flow meter Flow Meter Calibration Calibration system Flow meter weights Flow meter
Tests had to be stopped because of high temperature (40ºC) The RHVT made a hissing noise, possibly indicating cavitation Flow inside vortex generator was viewed – entrained air Observations Perspex Blind
Performance Measurements • Current results do not show any significant temperature change across RHVT or improved heating performance
Further Discussion • Experimental errors • Flow meter calibration and resolution • Calibration of other instruments • Heat loss • Resolution of thermocouples • Experiments are continuing • Planned experiments • Reduce clearances for bottom outlet and cone • Reduce inlet diameter • Redesign cone Revised cone concepts
Vortex Heat Generator management
Work Structure Team Bryan (Manufacturing Manager) Phillip (Technical Manager) Janice (Team Manager) • Instrumentation • Drawings • Manufacturing • Circulation system • Purchasing • Theory • RHVT design • Theory • Administration
Finance Sponsorship Expenditure
Theoretical investigation Conceptual design Drawings Manufacturing Experimentation Deliverables Time Management
Vortex Heat Generator conclusion
Conclusion • Existing devices and potential heating mechanisms were investigated • RHVT and experimental system with instrumentation were designed and built • Experiments to determine the performance of the RHVT were conducted
Conclusion • Current results do not show any significant heat from the RHVT • RHVT produced some noise that could be caused by cavitation but could also be air • Experiments are continuing
Acknowledgment Mechanical Workshop Especially Robert Dempster, Richard Pateman and Bob Dyer Electronics Workshop Especially Silvio De Ieso Academic Staff Dr. Richard Kelso Dr. Peter Lanspeary Dr. Wen Soong Dorothy Missingham Charlie Green Post-graduate Students Mohammadamin Miremadi Sarah Crook Kristy Hansen External Damion Weerts (One Steel) Matt Willis (Butlers Irrigation)
Questions Questions?