Ice Slurry TES for District Cooling

1,190 views
1,063 views

Published on

Effectiveness of Retrofitting
Ice Slurry Thermal Energy Storage
for an Urban Hospital Chiller Plant

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
1,190
On SlideShare
0
From Embeds
0
Number of Embeds
6
Actions
Shares
0
Downloads
48
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Ice Slurry TES for District Cooling

  1. 1. Effectiveness of RetrofittingIce Slurry Thermal Energy Storagefor an Urban Hospital Chiller Plant Stan Rott Marketing Director IDE Technologies
  2. 2. Executive SummaryThe main purpose of this study is to investigate the effectivenessof the retrofitting of an ice slurry storage system for the existingcentral chiller plant of a large size hospital.The study is also focused on improvement of the hospital’schiller plant efficiency as well as reduction of the annual electriccost by application of an ice slurry Thermal Energy Storage (TES)system utilizing water vapor as the primary refrigerant.The results are a nearly FLAT monthly Peak Demand curve, whichallows for a reduction of about 2,000 kW (~30%) compared tothe hospital’s current recorded Peak Demand data.
  3. 3. ObjectivesAssess hospital’s current specific power consumptionIsolate base load not related to comfort coolingEstimate existing chiller plant efficiencyEvaluate chiller plant power consumption after retrofittingwith ice slurry TES, based on one Vacuum Ice Maker (VIM)with a rated capacity of 1,000 TonsCompare current power consumption with the projectedpower consumption after retrofitQuantify monthly and annual electric savings resultingfrom the retrofitting of the chiller plant with TESEstimate the required scope of work
  4. 4. Existing Conditions Hospital Chiller Plant • 4 x 1,000 Tons • 3 x 1,000 Tons by Trane, plus 1 x 1,000 Tons by York • Chiller plant age: ~26 years • Critical application areas: Clean rooms & Surgery • 2 x 75 Tons • 1 x 35 Tons • Several 5 Ton units• Chiller plant capacity: ~4,200 Tons• Estimated specific power consumption: ~1.1 kW/Ton
  5. 5. VIM & TES Reservoir Preliminary Site Survey1. VIM will be installed on the rooftop2. Rooftop structure may need to be reinforced3. TES Tank has no limitation in terms of shape, form or materials of constructionHospital building crawl spacewould be retrofitted as a TES Retrofit Scope:Tank with total approximate • Application of a waterproof linervolume of 150,000 ft3 and • Buffer reservoir & associated pipingstored cooling capacity ofabout 50,000 Ton-hours
  6. 6. Design Consideration Storage Type • Daily/Weekly • Seasonal Tariff Structure • Peak Demand charges • Peak vs. Off-peak billing periods Control Strategy • Peak Demand reduction • Peak Demand set point control
  7. 7. Preliminary Data AnalysisHospital’s Power Consumption Data: hourly meter reading• October, 2009 to October, 2010Highest Annual Electric Peak Demand• July 6th: 6,054 kW
  8. 8. Preliminary Data AnalysisAnnual Load Duration Curve• October, 2009 to October, 2010Hospital’s Load Analysis• Base Electric Load: ~1,900 kW
  9. 9. Control Strategy Tariff Structure • Peak Demand Charges: 60% to 70% • Time-of-Day Charges: minimal differences from peak to off-peakFrom Date To Date Meter # kWhr Demand,kW Charge,$/kW Charge,$/kWhr Charge,$/mo From Date To Date Meter # kWhr Demand,kW Charge,$/kW Charge,$/kWhr Charge,$/mo 8/25/2010 9/24/2010 5656007 518,400 7/27/2010 8/25/2010 5656007 566,400 5656008 528,000 5656008 499,200 5656009 432,000 5656009 628,800 5656029 523,200 5656029 614,400 7031005 518,400 7031005 614,400 Total 2,520,000 5,768 Total 2,923,200 5,976On Peak Energy Consumption 1,257,556 On Peak Energy Consumption 1,397,027Off Peak Energy Consumption 1,262,444 Off Peak Energy Consumption 1,526,173CHARGES CHARGESPrimary Distribution Demand 13.36 77,060.51 Primary Distribution Demand 12.91 77,178.09Transmission Demand 7.14 41,183.52 Transmission Demand 6.90 41,246.35On Peak Energy Consumption 0.02 18,980.78 On Peak Energy Consumption 0.0061 8,535.15Off Peak Energy Consumption 0.0151 19,054.56 Off Peak Energy Consumption 0.0061 9,324.16System Benefit Charge 0.0059 14,867.99 System Benefit Charge 0.0059 17,246.87Temporary NYS Surcharge 0.0039 9,941.40 Temporary NYS Surcharge 0.0039 11,532.02Billing & Payment Surcharge 1.04 Billing & Payment Surcharge 1.04Total Meter Charge Total Meter ChargeMeter 37.56 Meter 36.31Meter Reading 9.90 Meter Reading 9.57Meter Maitenance 16.44 Meter Maitenance 15.89Tax Charges 4,323.59 Tax Charges 3,941.06TOTAL CHARGES 185,477.29 TOTAL CHARGES 169,066.51Percent of Peak Demand 64% Percent of Peak Demand 70%
  10. 10. Control StrategyTerminology Description• Process: Hospital’s Electric Load • Disturbance to the Process: Electric Load Fluctuations• Measurement: Real Time Electric Power Consumption Metering• Controller: Programmable Logic Controller (PLC) • Set Point: Monthly Peak Demand Level• Adjustment: Chilled Water Flow Rate
  11. 11. Control Strategy Implementation 11:00 pm – 4:00 am 5:00 am – 8:00 pm TES Load: 1.0 kW/Ton Process DisturbanceMeasurement Set Point TES Load
  12. 12. Design TargetsOne Time Incentives offered through State Org. & UtilitiesProgram Participation: Curtailable Service Category Program Peak Demand Reduction: 80% NYSERDA: $600.00/kW ConEd: $500.00/kW Demand Response: 10% NYSERDA: $200.00/kW NISO: CSP Participation Emergency TES Ballast: 10% N/A
  13. 13. Results Monthly Summary – March: TES Full Load Shift Design Day Design Day w/ TES Ice Slurry TES Charge/DischargeLoad Duration Curve LDC w/ TES Monthly Target Peak Demand: 2,750 kW
  14. 14. Results Monthly Summary – July: Highest Peak Demand 6,054 kW Design Day Design Day w/ TES Ice Slurry TES Charge/DischargeLoad Duration Curve LDC w/ TES Monthly Target Peak Demand: 4,820 kW
  15. 15. ResultsAnnual LDC: Before & After TES Monthly Peaks: Before & After TES Load Redistribution Peak Demand Reduction
  16. 16. ResultsKey characteristics of Ice Slurry TES• Independent TES Charge and Discharge Loops• Simultaneous operation of TES Charge and Discharge loops Highest Expected Discharge Rate
  17. 17. Results Ice Slurry TES Operation Period: March through October Peak Reduction Annuals Savings Summary* Month Pre- kW Post- kW Reduction $/kW Savings $ Jan 3072 3072 0 - $0.00 Feb 3060 3060 0 - $0.00 Mar 3108 2750 358 $18.80 $6,730.40 Apr 4932 2812 2120 $19.00 $40,280.00 May 5580 3750 1830 $21.87 $40,022.10 Jun 5864 4500 1364 $19.81 $27,020.84 Jul 6054 4820 1234 $21.87 $26,987.58 Aug 5968 4450 1518 $19.81 $30,071.58 Sep 5748 4430 1318 $20.50 $27,019.00 Oct 4456 2650 1806 $20.50 $37,023.00 Nov 3138 3108 0 - $0.00 Dec 3066 3046 0 - $0.00 Total $235,154.50 Simple Payback Period: 6 years (or less in cases when adding or upgrading chiller plant capacity)* The $/kW are indicative of ConEd service territory
  18. 18. Scope of SupplyRetrofit Scope• Vacuum Ice Maker – VIM850 (1,000 Tons)• TES Reservoir Retrofit (hospital crawl space mod’s)• Plate & Frame Heat Exchanger• Circulation System (pumps, piping, valves, controls, etc.)• Transportation to the Site• VIM Installation• VIM Maintenance Area• Structural Reinforcements (for roof installations)
  19. 19. ConclusionsAccomplished Project Goals Peak Demand Reduction Demand Response Improved Existing Chiller Plant Efficiency Improved Existing Chiller Plant Reliability Significant Annual Operating Energy Cost Savings Can Earn Utility IncentivesKey Characteristics of VIM Ice Slurry TES• Environmentally Friendly – Uses Water Vapor as the ONLY Refrigerant• Low Energy Consumption – less than 1.0 kW/Ton for ice making• RAPID and VARIABLE Discharge Capabilities, with COLD supply temps• Produces a pumpable and non-coagulating ice slurry• Uses a compact, simple, and low cost TES Tank
  20. 20. Contact Information Stan Rott Marketing Director IDE Technologies main: 1-516-734-0420 cell: 1-267-210-3396 shlomir@ide-tech.com www.ide-tech.com

×