Ice Pile Air ConditioningJoseph Cooper: Project LeadKylie Rhoades, Clara Echavarria, Jonathon Locke, Alex Gee

Agenda• Background• Problem Statement (Input on EER table)• Customer Needs• Functional Decomposition• Specifications/Constraints/Given• Concept Experiment• Concept Development (Input on alternate designs)• Concept Decision • Heat Exchanger Calculations (Input on inlet temperatures)• Initial Visual Representation of Unit Design

Project Background and Summary

• RIT has a goal of becoming carbon neutral by 2030 and a continuous vision of campus expansion.

• RIT will soon be the home of a brand new ice arena as well as the current home of Ritter Arena.

• Mission: Design a method to extract the cooling energy from a volume of ice (generated from an ice rink) effectively and efficiently.• On a game day at an ice rink, there are approximately 5 Zamboni

“dumps”, summing up to 500 ft3 (14.15 m3) • On a typical day of operation, 100 ft3 (2.83 m3) is discarded.• According to a density test, this will weigh approximately 2000 kg

per load or 10,400 kg on a game day (per 5 loads)

Problem Statement• Create a testing unit to which will demonstrate the feasibility

of obtaining a cooling capacity from waste ice. This small scale proof-of-concept will be in the form of an air cooling unit.

• This testing unit is to be comparable (ideally found much better) to cooling efficiencies of a typical water or evaporative cooled condensing unit with a COP of 3.8

• http://www.centerpointenergy.com

Equal to a COP of 3.8

Customer Needs

Functional Decomposition Tree

Specifications and Constraints

Preliminary Concept Experiment• Purpose:• Suspicion of creating an air gap around a pipe is thought of in theory• Run test to find if we are able to have a vertical heat exchanger pipe in

the ice box, and observe ice behavior during melting in this case.• After about 35 minutes:

Concept Development

Concept OnePros Cons

Auto Ice Settling Crush Piping

Known Ice-Heat exchanger SA Pump Required

Closed Loop Allows for Possible Coolant Piping Cost ($$)

No Filter Necessary Maintenance of Coolant Additives

Cleaning of Tank Around Pipes

Concept TwoPros Cons

Open system without refrigerant. Unknown ice behavior during melting.

Auto-settling of ice. Recirculation of the same water (will not get the full cooling effect).

No pipes needed. Pump required.

Need screen for pumping loop.

High enough flow rate?

Concept ThreePros Cons

No pump Less power in. Waste water.

No pipes needed. Need to source the water.

Water in is about 550F – consistent input temp.

Enough pressure from water to outweigh line losses?

More testing/less theory.

Risk Rank Proposed Mitigation

Is there a high enough flow rate to avoid cavitation?

2 Based on pump flow rate, start with enough water to eliminate this risk until we understand how the system behavior.

Unknown amount of exposure between working fluid and ice causing a low cooling rate.

3 Different spray patterns over top of ice to ensure even melting. If this is not helping, revert to heat exchange

Debris entering pump loop causing pump/system failure.

3 Implement a screen to filter out any unwanted debris.

Water leakage into component area.

1 Keep elements elevated from base of their compartment and/or seal them off.

Concept Risk Assessment for Selection

Likelihood Scale1 Low Risk Likelihood2 Moderate Likelihood3 High Likelihood

Selected Path for Design: Concept 2

• Concept 2 includes benefits from both 1 and 3.

• Can be fitted with a heat exchanger (Concept 1) if needed for appropriate cooling.• Heat exchanger will require:

• Design• Lead Time• Budget/Cost

Coolant to Air Heat Exchanger

Background:• Initial calculations are done with copper tubing• Future plans are to use a finned radiator• Coolant has been chosen as water• Air is to be moved evenly by 2 DC fans with flow rates required

by radiator• Pump to be sized based on radiators and associated head

losses

Cross-Flow Heat Exchanger

Cross Flow = AirTube Flow = Water

Given parameters for Initial Hx:

•Water Inlet Temperature = 0°C•Qwater = 1 gpm•Air Inlet Temperature = ~30°C•Air Flow Rate = 105.9 CFM or 3

m3/min•½” Copper Tubing

Prototype Output• Assume: • Pure Ice at 0oC• 5 gallon tank• 3.5 gallons of ice• 1.5 gallons of H2O• 300,000 J/kg latent heat of ice• 917 kg/m3 density of pure ice• 736 kg/m3 experimental density of Zamboni shaved ice

• 2773 BTU storage in Zamboni Ice• 3992 BTU/hr Cooling Load of Heat Exchanger• 45 Minutes of Run Time

Copper Tube Heat Exchanger Results

Total Cooling Load= 1.08 KW or 3692 BTU/hrRequired length of ½” diameter tubing= 96 ftTubing Layout:• 15” of straight tube• 1.5” diameter elbows• 1” gap between tubesTubing section (HeightxWidthXDepth)=16.5”x3.5”x.5”Total Size (HeightxWidthXDepth)= 16.5”x19.375”x8”