A Case Study of Latham Water District s Mohawk View High Lift Pump Station Rehabilitation

Transcription

1 A Case Study of Latham Water District s Mohawk View High Lift Pump Station Rehabilitation

2 Outline The Mohawk View High Lift Pump Station & Latham Water District Energy Incentive Programs Pump Evaluation Final Improvements Construction Design Changes Energy Savings and Incentives Q&A

3 TOWN OF COLONIE LATHAM WATER DISTRICT Provides drinking water and fire protection for 82,000 customers Ave. Daily Demand = 11.0 MGD Max Day Demand = 19.6 MGD Water District includes: Mohawk View Water Treatment Plant (30 MGD) Two (2) Main Pump Stations Mohawk View High Lift Pump Station (65% of Total Flow) River Road Pump Station (35% of Total Flow) Three (3) additional Booster Stations for local demand Latham Pump Station directly effects HLPS Nine (9) Water Storage tanks 430 miles of Water mains

4 TOWN OF COLONIE LATHAM WATER DISTRICT

5 The Mohawk View High Lift Pump Station (HLPS) Construction 1960 s & Upgraded 1980 s Equipment of Various Ages End of Useful Life Pumps no longer operating at optimum design point Flowrate ranges: 6.5 MGD annual average 5.0 million gallons per day (MGD) in Winter Months 15.5 MGD in the Summer Months Five (5) Vertical Turbine Pumps 400 Horse Power (hp) motors Design point: 3,500 gallons per minute (GPM), (5.04 MGD) 370 feet Total Dynamic Head (TDH) With one pump out of operation design capacity is 20 MGD (14,000 GPM)

6 The Mohawk View High Lift Pump Station (HLPS)

7 Energy Incentive Programs National Grid New York Upstate Commercial & Industrial Energy Efficient Incentive Program Incentive offer $0.197/kWh One-time Reimbursement NYSERDA (New York State Energy Research & Development Authority) Process and Efficiency Program Incentive offer $0.121/kWh One-time Reimbursement

8 Energy Incentive Programs National Grid New York Upstate Commercial & Industrial Energy Efficient Incentive Program Incentive offer $0.197/kWh One-time Reimbursement NYSERDA (New York State Energy Research & Development Authority) Process and Efficiency Program Incentive offer $0.121/kWh One-time Reimbursement

9 Pump Evaluation 96% of operation from 5.7 to 6.6 MGD Single pump had a design capacity of 3,500 GPM (5.04 MGD) Pump typically operating at run-out portion of the curve SCADA Flow Readings Jan 1, Nov 6, 2013 Flow Percent of Hours mgd gpm 0.1% mgd gpm 11.7% mgd gpm 10.6% 5.9-6mgd gpm 7.6% 6-6.1mgd gpm 12.7% mgd gpm 5.6% 96.0% mgd gpm 10.6% mgd gpm 17.7% mgd gpm 15.7% mgd gpm 3.6% mgd gpm 0.6% 0.6% mgd gpm 2.3% mgd gpm 1.1% 3.5% mgd gpm 0.0% Note: Readings taken at five minute intervals

10 Pump Evaluation 96% of operation from 5.7 to 6.6 MGD Single pump had a design capacity of 3,500 GPM (5.04 MGD) Pump typically operating at run-out portion of the curve for a single pump SCADA Flow Readings Jan 1, Nov 6, 2013 Flow Percent of Hours mgd gpm 0.1% mgd gpm 11.7% mgd gpm 10.6% 5.9-6mgd gpm 7.6% 6-6.1mgd gpm 12.7% mgd gpm 5.6% 96.0% mgd gpm 10.6% mgd gpm 17.7% mgd gpm 15.7% mgd gpm 3.6% mgd gpm 0.6% 0.6% mgd gpm 2.3% mgd gpm 1.1% 3.5% mgd gpm 0.0% Note: Readings taken at five minute intervals

11 Pump Evaluation System Curve Development Updated and used Town s Hydraulic Computer Model of the system Downstream Booster Station (Latham Pump Station) Operation Tank Levels SCADA Records

12 Pump Evaluation Ex. Design Head 370 ft Optimized Head Modeled Verified SCADA Readings ft BEP 83 74

13 Pump Evaluation Recommended Operating Range ft ft. Optimized Operation ft LPS includes a redundant pump and emergency generator, therefore, it s unnecessary to a design HLPS with LPS out of service

14 Pump Evaluation Recommended Pump Replacement Fourteen (14) alternative configurations were evaluated based on the following Minimum Energy Usage With and without Variable Frequency Drives (VFDs) Relatively short payback period Incentive available through National Grid Capital Cost

15 Pump Evaluation Recommended Pumps : Five (5) 400Hp Two (2) VFDs Five (5) soft starters Operating Range ft MGD@ 300ft. Optimized Operation ft w/ VFD 6.5

16 Recommended Improvements

17 Recommended Improvements

18 Final Improvements Submittal Process Electrical Contractor (O Connell Electric Co.) proposed a design change Original electrical design included: Two (2) 18 Pulse VFDs and Five (5) Soft Starters with four (4) manual switches Retrofitting existing switchgear Alternate Proposal Five (5) 6 Pulse VFDs with a Harmonics Filter Installation of a new 3,000 amp switchboard New Switchgear will allow individual pumps and VFDs to be taken offline No additional cost to the Town

19 Final Improvements Sequence of Construction: Install platform with new switchboard and 3000 amp feeder Temporally install two (2) VFDs, next to two of the existing pump motors Temporally install cabling between switchboard and VFDs Install a feeder between the new switchboard and existing gear Schedule a shutdown to intercept the existing 3000 amp feed and land at new switchboard Two (2) of the five (5) pumps operating on VFDs and the other pumps operating off existing gear

20 Final Improvements At this point O Connell demolished the unneeded section of the existing electrical cabinets Shutdown time was minimal with no effect on Town water supply Once demolition was completed, O Connell was able to install the remaining platform and remaining VFDs in the final location Once the three (3) final VFDs were installed and operating the existing pumps, the temporary VFDs could be disconnected and installed in their permanent location All five (5) existing pumps are now operating off of the new electrical gear

21 Final Improvements

22 Final Improvements

23 Final Improvements

24 Final Improvements

25 Final Improvements

26 Final Improvements Summary Switching from 18 pulse VFD to 6 pulse VFD with harmonic filter Standard 6 pulse VFD can cause interference with other neighboring equipment, shorten equipment life, and negatively impact power quality Standard 18 pulse VFD mitigates these effects, however, this requires a much larger cabinet O Connell proposed a 6 pulse VFD with passive harmonic filter which would mitigate the negative effects from a standard 6 pulse VFD

27 Final Improvements White papers were provided to prove the benefits of the change This allowed all five (5) pumps the ability to operate on their own VFD This gives the Town maximum flexibility to meet the demand and keep the pumps in optimal operating range and ease of operation. Keeps their Water-to-Wire Efficiency as high as possible

28 Final Improvements Pump Installation Once electrical gear was installed and operational, the General Contractor was able to install the new 400 HP pumps, motors, and piping

29 Energy Savings and Incentives National Grid - New York Upstate Commercial & Industrial Energy Efficient Incentive Program Only the necessary quantity of pumps are considered for payback calculation Infrequent flowrates or redundancy are not include in the payback 96% of operation is with one (1) or two (2) pumps Therefore, National Grid will only consider two (2) pumps with associated electrical upgrades

30 Energy Efficiency Evaluation National Grid - New York Upstate Commercial & Industrial Energy Efficient Incentive Program One-time reimbursement Based on amount of energy saved per year (kwh/yr) Equipment meets certain cost and savings parameters Incentive offered for this project was $0.197/kWh

31 Energy Efficiency Evaluation Table 5.1: Results of Energy and Cost Calculations for Installed Improvements Parameter Existing Installed Improvements Difference kwh/yr 2,775,000 2,415, ,000 kw/yr 6,200 3,550-2,650 kwh $/yr at $0.072/kWh $198,800 $173,100 -$25,700 kw $/yr $20,700 $11,800 -$8,900 Total $/yr $219,500 $185,000 -$34,500 Annual Average Water-to-Wire Efficiency 63.4% 77.8% +14.4% Annual Average gpm/kw Run hr/yr 9,363 8, Incentive ($0.197/kWh saved per year) - $70,600 -

32 Energy Efficiency Evaluation Table 6.1: Project Costs Contract 1A General Construction Bid $ 758,800 Contract 1B Electrical Construction Bid $ 409,900 Engineering, Legal, Misc. $ 135,600 Total $ 1,304,300 Incentive Eligible Costs Item Quantity Unit Price Total Cost Vertical Turbine Pumps 2 $ 91,000 $182,000 Variable Frequency Drives (VFDs) 2 $ 58,057 $116,114 Total $298,114 National Grid Simple Payback 8.64 years ($298,114 divided by $34,500)

33 A Case Study of Latham Water District s Mohawk View High Lift Pump Station Rehabilitation