Ice Energy Extraction

Alex GeeJon LockeJoe CooperKylie RhoadesClara Echavarria

Ice Energy ExtractionBackgroundHockey arenas are some of the most energy demanding and least efficient buildings

Ice disposal from Zamboni amounts to 100ft3 per day, up to 500ft3 on a game day.

Between 700kJ and 3500kJ of cooling are being wasted from phase change aloneJoeProject PurposeProvide data on extraction efficiencies and methodsCoefficient of Performance (COP)Type of working fluid, method of heat transfer (Convection? Conduction? Direct Contact?)

Provide a look forwardCost and energy savings potential from wasted arena icePotential of other similar sources (winter snowfall)

Joe"Customer" Needs

JoeSpecificationsJoeConstants and givens (from vendor)CFM air, GPM water, rating (q) Inlet temperatures (used to figure out the fluids densities and specific heat capacities)Constraints and Assumptions- Ideal gas Incompressible flow Constant Pressure (Cp) Uniform FlowOutputUA value at different flow rates of air and waterHeat Exchanger Feasibility Calculations: Part 1Design Calculations and TheoryClara6Constraints and Assumptions- Ideal gas Incompressible flow Constant Pressure (Cp) Uniform FlowHeat Exchanger Feasibility Calculations: Part 2Design Calculations and TheoryClara7Measured dataT of water in and out of radiatorWin from plug power meterCoolant Flow RateConstants and givensFluid properties of water (density, Cp)Constraints and AssumptionsIdeal gasIncompressible flowConstant Pressure (Cp)Uniform FlowOutputFinal/Overall COP of unitFinal Efficiency Functional Diagram (Final Testing)

Design Calculations and TheoryClara8

Alex

Total Assembly Cost: $493.06AlexTesting OverviewGoal: Determine the best way of melting the ice (spray pattern) and optimize the water to ice ratio to achieve the highest COP possible.

KylieGeneral Procedure GuidelinesFill plumbing systemSet valve to theory flow rateConstant Ice Volume: 30LInput desired Water VolumeTurn on system fan and pumpTake initial readings from all thermocouplesRecord values every 2 minutesFor Part I only, take picture of tank every 4 minutesKyliePart I: Determine Spray PatternCross Design

Single Input

Downpipe Input

KyliePart I: Determining Spray PatternOne test for each patternConstant Ice:Water Ratio: 30:10 L

Data eliminated single input over tankCross and downpipe design equally better

Downpipe design selectedPicked circulating downpipe by observation of better mixing performanceKyliePart II: Optimization of WaterUsing downpipe design from Part I:Constant Ice Volume: 30L

Varied Water Volume: 5-20L of Water (5L, 7.5L, 10L, 12.5L,15L, 20L)

Assumption: As water is increased from 5 to 20L, the resulting COP will be normally distributed

Optimal Operating Point: 30/12.5L of Ice/Water

JonResults - Test vs TheoryThe experimental COP did not match the theoretical COP.

Power draw of the system was ~30 Watts higher than expected, decreasing COPBudgetary and model restrictions (about $150 and 5 gpm) limited pump selection to oversized units that consumed 80 Watts more than an ideal pump.

JonResults - Test vs. Theory Contd.The fan had a 12% reduction in flow compared to the manufacturers dataAfter recalculating the theoretical COP with this reduced flow and including 20% error bounds, the following table was produced.

*These results match the experimental data

JonConclusionsPotential energy savings: >314% increase in COP from a traditional system is substantial. For every 1000 kW of cooling of the current system, the proposed system would provide ~3140 kW of cooling w/o affecting overall operating costs.JonSystem ImplementationCurrent RIT ice rink: Four separate, equal, cooling systems.They are comprised of two primary pumps that pump the warm fluid to a cooling tower, a second set of pumps that move the fluid through the condensers and the heat exchanger unit.

There is potential to replace one of the four systems in the adjacent to the room where the Zamboni is stored.

An ice dump pit could be placed in the floor of the storage room and water lines could be run to the adjacent room containing the heat exchanger unit (which could be reused to save on capital expenses).

JonA Look ForwardArena Ice from June-SeptemberAssume minimum 100ft3 per dayEnergy savings over conventional system of 22650MJ, amounting to $6305-year savings $3,150

Ice Arena Year RoundAssume minimum 100ft3 per dayEnergy savings over conventional system of 67950MJ, amounting to $1,8905-year savings $9,450

AlexAlternate ApplicationThe information learned in this project can be applied to similar ideas to help reduce the use of energy from other parts of campus:

Annual snowfall in Engineering Lot JAssume less than half of the snowfall (2.5m) is usable200mx200mx1m (snow volume of Lot J)Energy savings over conventional system of 679000MJ, amounting to $18,8505-year savings $94,250AlexSpecial ThanksDr. Stevens ~ Theory Support

Dr. Hanzlik & Mr. Wellin ~ Theory and equipment

Rob Kraynik ~ Machine Shop

Rick Lux ~ Mentor