university ridge at e ast stroudsburg university

UniversityUniversity Ridge Ridge atat

EEast Stroudsburg Universityast Stroudsburg University

Matthew CarrMatthew Carr

Spring 2007Spring 2007

Mechanical OptionMechanical Option

Faculty Advisor: Dr. FreihautFaculty Advisor: Dr. Freihaut

UniversityUniversity Ridge Ridge atat

East Stroudsburg UniversityEast Stroudsburg University

Outline Project Team Building Information Existing Mechanical Conditions Redesign Goals Mechanical Redesign Redesign Analysis Photovoltaic Breadth Recommendations & Conclusions Acknowledgements Questions

Penn State Architectural Engineering Thesis

University Ridge at East Stroudsburg

Matthew Carr

Mechanical OptionSpring 2007

Building Name:University Ridge at East Stroudsburg

Building Owner:University Properties Inc.

Building Developer:Capstone Development Corp.

Architect:Design Collective Inc.

Engineers:Greenman-Pedersen Inc.



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Project TeamProject Team

Location:

East Stroudsburg, PA on the East Stroudsburg University Campus

Building Statistics: Student Residence – Apartments 541 Beds – 136 Units 3 stories plus an occupied walk in basement 140,000 square feet – 10 Buildings Development Cost: $27,200,000 Construction Cost: $15,750,000 Construction: August 2004 – August 2005



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Building InformationBuilding Information



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Building InformationBuilding Information

Building Site Plan:

Heating System: Hot water coil duct furnaces – Dedicated unit for each housing unit Hot water supplied by a dedicated residential hot water heater Electric unit heaters for unoccupied spaces.



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Existing Mechanical Existing Mechanical ConditionsConditions

Cooling System: Chilled water coil duct furnaces – Dedicated unit for each housing unit Chilled water supplied by a dedicated DX condensing unit

General: Individual exhaust fans for bathrooms Naturally ventilated living spaces to decrease load

Combined Heat & Power Goals: Reduce emissions while increasing overall fuel usage

for producing power Provide space heating using waste heat from power

production Provide chilled water with absorption cooling which

utilizes the waste heat from power production Reduce fossil fuel usage Determine feasibility of a payback period

Decrease annual operating cost



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Redesign GoalsRedesign Goals

What is Combined Heat and Power? Electricity is generated on site by a prime mover Waste heat is used for the heating and cooling processes CHP typically runs at a lower operating cost but has a higher first cost Load leveling increases operating efficiency

Main Components of Combined Heat and Power? Prime Movers (gas turbines, reciprocating engines, etc.) Absorption Chillers Chilled Water Storage Tanks Cooling Towers Pumps and Distribution



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Mechanical RedesignMechanical Redesign

Spark Gap Feasibility Analysis? Determination of difference between natural gas and electricity cost:

Natural Gas:

$1.33/therm

Electricity:

$0.0919/kWh

$26.94 - $13.30 = $13.64

A spark gap of $12.00 or greater is usually considered a viable solution.



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Determination of Prime Mover Building electric demand load of 366 kW Building heating load of 775 MBH Building cooling load of 177 tons

Prime Movers Considered Reciprocating Engines Fuel Cells Natural Gas Turbines



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Natural Gas Micro-turbine & Absorption Chiller Selection Integrated micro-turbine and chiller/heater power system Comes as packaged unit integrated with controls Unit made up of 60 kW micro-turbines Heat exchanger contained within the absorption chiller Good under part load condition as micro-turbines can be

selectively turned off or on as needed Fewer moving parts than internal combustion engines Typically reduced emissions over internal combustion

engines Integrated inverter optimizes efficiency Integrated system allows for reduced installation cost.



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Integrated Micro-turbine Chiller/Heater System Specs:

4 – 60 kWe Micro-turbines



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Net Power

Output (kWe)

Fuel Consumption LHV (MBH)

Cooling Output (Tons)

Heating Output (MBH)

Flow Rate (gpm)

Net System Efficiency

ISO Day (59F) 227 3,000 142 1,282 297 84%

Design CoolingDay (95F)

193 2,800 124 - 297 76%

Heating Day (32F) 231 2,800 - 1,100 297 68%

Heat Recovery: Waste heat from turbines recovered in the absorption chiller High temperature generator and evaporator sections used as heat

exchanger Production of 140°F water used for hot water heating in the fan coil

units.



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Double-effect Absorption Chiller: Waste heat used to regenerate LiBr solution which acts as the

condenser which is usually electrically powered Cooling tower needed for heat removal from the condenser Use of LiBr and water eliminates for ozone depleting refrigerants



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Existing Installation Example:



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Chilled Water Storage: Chilled water storage used to level and shift the cooling load to

increase efficiency Allows for chiller size reduction



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Energy Analysis: Energy analysis was done using RETscreen CHP energy analysis

program Analysis run using UTC Pure Comfort system, the determined cost data

and calculated loads The following table shows the operating capacity of the system



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Redesign AnalysisRedesign Analysis

Electricity delivered to

load

Electricity exported to

grid

Remainingelectricityrequired

Heatrecovered

Remainingheat

requiredPower

system fuelOperating

profit (loss) Efficiency

Operating strategy MWh MWh MWh million Btu million Btu million Btu $ %

Full power capacity output 2,102 1 509 7,100 206 27,423 175,052 52.0%

Power load following 2,102 0 509 7,095 211 27,413 174,987 52.0%

Heating load following 1,030 1 1,581 5,955 1,350 13,442 59,762 70.5%

Monthly System Characteristics:



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Existing Cost: Existing mechanical system cost determined to be $2.1 million dollars

as built



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Estimated First Cost:Equipment Size Installed Cost Quantity Total

Prime Mover 240 kW $2,500 240 $600,000

Cooling Tower 205 (tons) $95.50 (per ton) 2 $39,155

Absorption Chiller 142 (tons) $1197 (per ton) 1 $170,000

Storage Tank - $17,000 - $17,000

Expansion tank 2 - 266 (gal) $3,325 2 $6,650

4" Service pad 2835 s.f. $180 (per c.y.) 35 (c.y.) $6,300

Chilled Water Pumps 1 1/2" 100gpm $3,875 8 $31,000

Cooling Water Pumps 3" 385 gpm $6,175 2 $12,350

Piping - - - $264,332

$1,146,787

System Payback: System payback was also calculated using RETscreen CHP energy

analysis program



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System Payback:



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Cumulative cash flows graph

Year

Emissions Analysis: The following tables were generated using manufacturers data and the

national grid average for emissions



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lbm Pollutantj /kWh U.S.

Fuel % Mix U.S. Particulates SO2/kWh NOx/kWh CO2/kWh

Coal 55.7 6.13E-04 7.12E-03 4.13E-03 1.20E+00

Oil 2.8 3.03E-05 4.24E-04 7.78E-05 5.81E-02

Nat. Gas 9.3 0.00E+00 1.26E-06 2.36E-04 1.25E-01

Nuclear 22.8 0.00E+00 0.00E+00 0.00E+00 0.00E+00

Hydro/Wind 9.4 0.00E+00 0.00E+00 0.00E+00 0.00E+00

Totals 100.0 6.43E-04 7.54E-03 4.44E-03 1.38E+00

lbm Pollutant /kWh Prime Mover

Fuel ParticulatesSO2/kWh NOx/kWh CO/kWh

Nat. Gas. 2.37E-04 n/a 2.15E-04 8.60E-05

Emissions Analysis: RETscreen CHP energy analysis program was also determined the GHG

emissions produced by the proposed system and compared to the base case



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Years of occurrenc

e

Base caseGHG

emission

Proposed caseGHG

emission

Gross annualGHG

emissionreduction

GHG credits

transaction fee

Net annualGHG

emissionreduction

Combined cooling, heating & power project

yr tCO2 tCO2 tCO2 % tCO2

1 to 2 2,282 2,046 236 0% 236

Net annual GHG emission reduction 236 tCO2

is equivalent

to 48.0 Cars & light trucks not used

Photovoltaic Basis: Photovoltaic shingles built into sloped roof Able to offset peak power loads during the day reducing the grid

dependency of the CHP system Drawbacks: expensive, inefficient, minimal architectural effect



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Photovoltaic BreadthPhotovoltaic Breadth

PV Capacity and Cost Analysis: The analysis of the PV cells was done using RETscreen PV



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Photovoltaic BreadthPhotovoltaic Breadth

PV Cost: $557,476

Energy Delivered: 49 MWh/yr

Simple Payback: 12.4 yrs.

Conclusion: Increased total energy and fuel efficiency Lowered operating cost Higher initial cost Lower emissions and greenhouse gases



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Recommendations & Recommendations & ConclusionsConclusions

Recommendations:Given the previously determined data and facts, it is recommended that this CHP tri-generation system be implemented as it has a payback timeframe for that of a university and would save money and energy use in the long run

Thanks to the Following:

Architectural Engineering Faculty and Staff Faculty Advisor: Dr. Freihaut The AE Class of 2007 My Friends The GPI Mechanical Department My Family



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AcknowledgementsAcknowledgements



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QuestionsQuestions

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