THE PENNSYLVANIA STATE UNIVERSITY...The Trane Trace700 program was used to determine monthly energy profiles over the 24 hour time step for typical monthly weekday, weekend and design

THE PENNSYLVANIA STATE UNIVERSITY

DEPARTMENT OF ARCHITECTURAL ENGINEERING THESIS 2003-2004

THE PENNSYLVANIA STATE UNIVERSITY DEPARTMENT OF ARCHITECTURAL ENGINEERING THESIS 2003-2004

NEW INDEPENDENCE HIGH SCHOOL/SHARED USE FACILITY INDEPENDENCE, OHIO

FEASIBILITY STUDY FOR THE IMPLIMENTATION OF TRIGENERATION

AT NEW INDEPENDENCE HIGH SCHOOL/SHARED USE FACILITY

INDEPENDENCE, OHIO SPRING 04 THESIS REPORT

John Shaw

MECHANICAL OPTION JOHN JOSEPH SHAW PFC – DR. FREIHAUT SPRING 04 THESIS REPORT 05APR04 - 2 -






Table of Contents Table of Contents................................................................................................................ 4 Executive Summary ............................................................................................................ 5 Credits and Acknowledgements.......................................................................................... 6 Project History and Background.......................................................................................... 7 Existing Mechanical Conditions ........................................................................................ 10 Design Parameters ........................................................................................................... 10 Existing Systems Overview and Comments...................................................................... 11 Project Problem Background ............................................................................................ 16 The Problem ..................................................................................................................... 19 Cogeneration/Trigeneration Feasibility ............................................................................. 20 Summary and Conclusion................................................................................................. 46 Bibliography ...................................................................................................................... 48 Appendices ....................................................................................................................... 50




Executive Summary The Spring Thesis redesign involves a study of cogeneration/trigeneration and the feasibility of its implementation to the current thesis building central plant. Cogeneration is the industry term that describes the conversion of chemical energy into two useful alternate energy forms through the combustion process. The type of equipment may be either a microturbine combustion engine or a reciprocating engine. The two alternate energy forms are thermal (hot water or steam) and electrical energy. When the thermal energy is also used for cooling, the industry uses the term trigeneration. Philosophically, Design Professionals use trigeneration to maximize the energy efficiency of the combusted fuel source. That energy efficiency is defined as the total energy used (output) per the total energy combusted (input). The building is treated as a single energy consuming entity. Cogeneration implementation involves three general strategies. First, produce dedicated energy absent of traditional building energy connections. Second, produce energy in a load shaving manner while remaining connected to the traditional building energy methods (electric utility grid and some chemical for thermal energy production),and the spring thesis redesign strategy. Third, produce excess energy to be sold back to the utility. In order to determine the selection of cogeneration equipment, a determination of the building electrical and HVAC energy demand on an hourly time step must be determined. The Trane Trace700 program was used to determine monthly energy profiles over the 24 hour time step for typical monthly weekday, weekend and design day profiles. In addition, the program calculates energy consumption costs and calculates an economic summary of financing, installation and operating costs based on input energy rates collected from utility suppliers and installation and maintenance costs collected from vendors or experienced maintenance personnel. Since the building is a secondary education facility, the electric and thermal loads dominate the hours of 7am-11pm with a small base load during the non-occupied hours. Cogeneration equipment was selected to displace the building base load and meet the typical weekday load. The electric utility remains connected to provide partial load for non-typical operating conditions. One existing air cooled chiller and two existing boilers remain to provide supplementary cooling and hot water thermal needs for cooling to the proposed hot water absorption chiller. The equipment selected utilizes the chemical energy and average of 79% efficiency in lieu of traditional building energy connections that utilize approximately 42%-50%. The equipment displaces the majority of the existing building electrical and thermal demand. This reduces fossil fuel energy demand. In addition, the microturbine and reciprocating engines produce less air pollution to the environment than traditional energy production processes. However, a cogeneration system is much more expensive to install and maintain when compared to the current existing design. Based strictly on a cost decision, the cogeneration strategy is not currently a cost effective energy solution. However, Federal and State grants do exist to offset some of the first costs, and a growing market will further reduce these costs as equipment manufacturing increases. The Energy Information Administration predicts a continued growth in electricity demand without the addition of power generation plants for the next 10-15 years which will further increase electric rates. Facilities that produce their own power onsite will avoid these costs as well as avoid expensive pollution reduction measures required at large generation plants. The integration of cogeneration with the thesis project building is partially successful.




Credits and Acknowledgements I personally thank the following:

• Mr. David J. Laurenzi, Independence Schools District, for permitting my use of the Independence project during thesis.

• Mr. David Andreano RA, Sear-Brown, for providing assistance to thesis questions throughout the year and acting as Liaison for securing permission to use the Independence Project.

• Mr. Rick Marusczewski PE, Sear-Brown, for providing assistance to mechanical thesis questions throughout the project.

• Dr. Freihaut, PSU AE Department Faculty, for his interest in building total energy consumption saving strategies and environmental emissions reduction: his interest in the current and upcoming technologies for independent building energy production, and for providing the primary technical consultant services throughout the Spring Thesis.

• Mrs. Laura Miller, PSU FEI, for her strong contacts with the energy industry. • Mr. Mark Galetka, IUP Physical Plant, for opening his cogeneration facility for a tour

and unselfish willingness to provide any assistance and answer questions as needed.

• Mr. Rick Espositor, Electric Illuminating Company, for providing information and assistance with generation plant emissions and tariff information.

• Mr. Dave Glab and Mr. Brian A. Bloom, Allegheny Power, for providing information and assistance regarding cogeneration connections to utility grids.




Project History and Background The New Independence High School Shared Use Facility grew from a need first proposed by the Independence Schools district, Independence, Ohio in 1995 and evolved into the facility currently in construction. However, this need first involved the design and development of a new middle school and renovation of the existing high school. The community rejected this bond issue and concluded a new high school the more reasonable alternative. In 1997, the Independence Schools district resubmitted a bond issue for a new high school. The community agreed but urged the City of Independence government to assist the school district. Both, Independence Schools district and the government of the City of Independence developed three primary goals. First, both desire the best feasible educational facilities for Independence students. Second, both must reduce the additional tax dollar demand from the community for the new and renovated facility. Third, the City of Independence shall participate with minimal disturbance to existing financial and operating plans. In 1999 the City of Independence purchased land adjacent to the existing High School. The purchase funds allowed the Independence Schools district to proceed with urgently needed repairs, upgrades, and an addition to the existing high school. However, due to city population growth and extensive active community activities, Independence Schools and the City of Independence revised their new school vision into the New Independence High School Shared Use Facility. The existing middle school presented significant challenges to meeting the school district’s middle school curriculum and abandoned this project. However, the existing high school offered many potential alternatives and Independence Schools and the City of Independence agreed a new high school, that contained class and sport facilities accessible to the Independence community in conjunction with the high school students, fulfilled their original three goals. This opened the way for a design professional team selection.1 In 2001, 2002, and after considering many proposals, Independence Schools and the City of Independence selected Sear-Brown, Then Design Architecture Ltd, and R.C.A.L Architects Inc to provide professional design services for this approximately 33 million dollar project. These services include renovations of the existing high school for conversion to the Independence Middle School and design of the 114,330 square foot, partial two level, New Independence High School Shared Use Facility. Sear-Brown provided Architectural, Site, Structural, Mechanical, Electrical, Plumbing, and Fire Suppression design services supported by Then Design Architecture Ltd and R.C.A.L. Architects Inc. Interestingly, the architects chose a colonial/federalist style for the architectural feel to integrate with local building styles. This style provides a sturdy, modern, long term look to reassure both students and community residents of the school district’s and city’s commitment to secondary education and community activities. The new high school wall envelop consists of brick face/brick veneer facades, one inch air space, one and one-half inch rigid insulation and eight inch concrete masonry units attached to structural steel. In finished spaces, the wall envelop further consists of gypsum board on metal furring strips. Roof construction consists of one inch metal roof deck, three inch rigid insulation, and either built up roof membrane for horizontal roofs or shingles for pitched roofs all supported by structural steel. Glazing consists of a variety of one-eighth inch double glaze windows of various coatings depending on location. The new high school envelop




construction resembles the converted middle school envelop construction. Regarding applicable codes, the design professionals complied with the Ohio Building Code, applicable National Fire Protection Association standards the Americans with Disabilities Act, and the Ohio School Facilities Commission. The design professionals did not require special zoning for the new facility. In early 2003, Independence Schools and the City of Independence received bids, offered multiple prime construction contracts to approximately 22 prime contractors and selected Turner Construction to provide construction management services for this traditional design, bid, build project. Independence Schools desires the project construction completion to occur prior to the beginning of the fall 2004 school year. The facility is a modern secondary education facility designed for 600 students, 30 teachers, and 15 staff. Although the school district proposed many sites to the City of Independence, the new high school site resides on land adjacent to the existing high school/renovated middle school. The City of Independence, a semi-urban township near the City of Cleveland, purchased and leases the land to the Independence Schools district. Therefore, many site utilities infrastructure already exists and the project merely required utility additions rather than new installations as with Greenfield sites. Both the City of Independence and the Independence Schools District valued the current construction site due to the community’s familiarity with the location and the ability to harmonize community space use and function needs with the school district’s needs. The facility contains a rich diversity of space types including general classroom, laboratory classroom, administration, library/media center, full auditorium/stage, kitchen and dining, general trades or shop space, music practice and education, sports gymnasium and supporting facilities, indoor field house containing tennis courts and track, and integrated community general meeting use space. In order to meet modern technological education standards, the Owner’s and Design Professionals provided a variety of building systems. These systems include HVAC, plumbing, fire-suppression, security, telecommunications, computer network backbone with internet access, closed circuit television systems, card access, intrusion detection, lighting and a central facility management system. Design Parameters During the entire project, various general and discipline specific parameters affected the design approach. These design parameters include governmental, program, cost, site, and HVAC or system type. Since the project involves secondary education, the Owners, the Design Professionals, the Public, and the Local, State, and Federal Government all actively and passively participated in the project to establish needs and standards. Federal, State, and Local governments regulate and mandate standards for Elementary and Secondary education in addition to general building code standards. The state of Ohio produces and publishes the Ohio Building Code that establishes construction standards for all construction within the state. This code reflects the national building codes such as the BOCA Building code or the International Building Code, but Ohio modifies these codes for Ohio needs. In addition, the Ohio Schools Facilities Commission, http://www.osfc.state.oh.us/, establishes comprehensive program standards for school districts that renovate or construct educational facilities. General MECHANICAL OPTION JOHN JOSEPH SHAW PFC – DR. FREIHAUT SPRING 04 THESIS REPORT 05APR04 - 8 -

http://www.osfc.state.oh.us/



program requirements include general classroom, laboratory classroom, administration, library/media center, full auditorium and stage, kitchen and dining, general trades or shop use, music practice and education, sports gymnasium and supporting facilities. As mentioned in the Project Background section, the facility is a modern secondary education facility designed for 600 students, 30 teachers, and 15 staff. Figures 1 and 2 indicate the general program arrangement.

Figure 1




Figure 2

Existing Mechanical Conditions Design Parameters During the entire project, various general and discipline specific parameters affected the design approach. These design parameters include governmental, program, cost, site, and HVAC or system type which includes central plant. Federal, State, and Local governments regulate and mandate standards for national energy consumption and conservation, general state building codes and standards, and Elementary and Secondary education standards. At the national level President George W. Bush stated, “America must have an energy policy that plans for the future, but meets the needs of today…” and revised America’s National Energy Policy. In 1999, America consumed 3.098 quadrillion btu’s of energy. At the state level, the state of Ohio produces and publishes the Ohio Building Code that establishes construction standards for all construction within the state. This code reflects the national building codes such as the BOCA Building code or the International Building Code, but Ohio modifies these codes for Ohio needs. In addition, the Ohio Schools Facilities Commission, http://www.osfc.state.oh.us/, establishes comprehensive program standards for school districts that MECHANICAL OPTION JOHN JOSEPH SHAW PFC – DR. FREIHAUT SPRING 04 THESIS REPORT 05APR04 - 10 -

http://www.osfc.state.oh.us/



renovate or construct educational facilities. General program requirements include general classroom, laboratory classroom, administration, library/media center, full auditorium and stage, kitchen and dining, general trades or shop use, music practice and education, sports gymnasium and supporting facilities. Many design parameters and constraints affect the HVAC system concept, type and configuration, and equipment type. Foremost, the Ohio School Facilities Commission establishes minimum requirements and publishes these requirements in a design guideline. Chapters six and eight discuss program, including environmental features, and HVAC respectively. Appendix A includes a printed copy of portions of chapter eight. The reader may refer to this appendix for more detailed information. Regarding program HVAC support, the design guide briefly discusses ventilation and requires “…higher than normal ventilation requirements.” The design guideline also requires compliance with ASHRAE 90.1 for minimum energy performance criteria. The design guideline prefers four HVAC system types and only permits alternatives if the Design Professional completes an evaluation detailing the system annual operating cost, which includes maintenance cost and installation costs, and submits the report for approval to the Ohio School Facilities Commission. These system types include Central Plant Variable Air Volume System with Reheat Terminals, Central Plant Variable Air Volume System with Fan Powered Reheat Terminals, Water Source Heat Pump, and Central Plant Dual-Duct Constant Air Volume Systems with Dual Duct Constant Volume Terminals. For the New Independence High School/Shared Use Facility, the HVAC Design Professional chose the Central Plant Variable Air Volume System with Reheat Terminals. The facility receives electrical energy from The Cleveland Electric Illuminating Company, a subsidiary of First Energy, and natural gas, for thermal energy, from East Ohio Gas Company, a subsidiary of Dominion. Cleveland pays one of the highest utility rates in the country. Appendix B includes copies of utility rate information. All Owners desire maximum product for minimum cost. However, the New Independence High School Owners understood the importance of a modern facility to meet new education demands and challenges and accommodated the slightly higher than normal cost for this facility. The HVAC construction installation cost for this project is approximately 4.381 million of a total project construction cost of approximately 33 million. This ratio is approximately 13.3% and results in a $21.73 HVAC cost per square foot. This cost only involves the HVAC and does not include the other traditional mechanical plumbing and fire suppression systems costs. RS Means indicates that the high HVAC range for this type of building is $3,987,00. Therefore the HVAC costs appear slightly higher than the normal range. Annual operating costs are currently undetermined since the facility is in construction and detailed energy/cost modeling was not conducted by the HVAC Design Professional. Existing Systems Overview and Comments


Generally, the New Independence High School/Shared Use Facility uses variable temperature conditioned, constant or variable air to moderate heating and cooling loads, and provide ventilation, within the facility. Sixteen air-handlers, two packaged rooftop units, three make-up-air units, and two air-recirculation units support the nineteen primary zones of the 114,030 square foot plus building. Two rotary screw, air cooled chillers provide cooling and a battery of eleven modulating output, hot water boilers provide the heating or cooling needs. In addition, a battery of



constant and variable volume pumps distribute the 40% glycol, chilled or hot water to the system coils. Only one packaged rooftop unit utilizes DX cooling and neglects the use of chilled water. As mentioned earlier, Specifications section 17000 – Facility Management System includes the detailed sequence of operations for all the HVAC equipment. This 130 page section may be made available at the instructor’s request. Refer to Appendix C for HVAC system zoning plans. COOLING PLANT The central cooling plant consists of:

• Two air-cooled, rotary screw chillers, and pump distribution. • The general control logic for these systems involves interlocking with the Facility

Management System (FMS) system. The chillers have dedicated controllers that maintain proper operation. During unoccupied mode (managed by time clock) or night set back, the controller cycles the chillers to maintain chilled water temperature setpoints. During occupied mode (managed by time clock), the controller stages the chillers to maintain chilled water temperature setpoints. The control sequence includes pump current status as well as internal chiller alarms communication to the FMS.

HEATING PLANT The Heating plant consists of:

• eleven natural gas fired, separated combustion air, multi-staged, hot water boilers form two batteries (one for the school and one for the community facility), and pump distribution.

The general control logic for these systems involves interlocking with the FMS system. The boilers have dedicated controllers that maintain proper operation. During unoccupied mode (managed by time clock) or night set back, the controller cycles the boilers to maintain hot water temperature setpoints. During occupied mode (managed by time clock), the controller stages the boilers to maintain hot water temperature setpoints. The control sequence includes pump current status as well as internal boiler alarms communication to FMS. The following diagrams illustrate the current cooling, heating, and main electrical switchgear system schematics.




Cooling Plant Schematic







Heating Plant Schematic







Electrical Main Switchgear Schematic




Project Problem Background Rather than choose a different HVAC system, design and model the system, then compare the predicted performance with the current design, this thesis project involves looking at the building as a single, electric and thermal energy consuming entity and researching a possible way to reduce that energy consumption. Traditional (non-science and technology buildings that are intense energy consumers) buildings utilize two fundamental energy forms, chemical and electrical. Electric generating stations produce electricity by coal combustion, nuclear, and hydrology methods. Coal combustion dominates due to relatively cheap fuel costs. Coal combustion plants drive electric generators that produce electricity at the required overhead, three-phase voltage for distribution across utility grids and finally to the building. However, typical coal combustion generating plants produce electricity an average of 34% efficiency for the total input fuel source. Transmission and transformer losses reduce this efficiency to approximately 32% reaching the building. Much of the generating station combustion process is released to the atmosphere as waste heat, water vapor, and combustion products emissions. Chemical energy forms, used to produce thermal energy, include natural gas, propane, and diesel fuel. These chemical energy forms are combusted in boilers that produce either hot water or steam with the most “efficient” equipment models utilizing up to 98% of the input fuel source (but typical equipment efficiencies range between 80%-90%). Buildings consume different proportions of chemical and electrical energy depending on building use, equipment type and equipment electrical efficiencies. In other words, lighting systems utilize approximately 20%-30% of the incoming 32% electrical energy to produce light. Motors utilize 90%-95% of the incoming 32% electrical energy. Thermal energy is lost through pipe distribution, heat exchangers, coils etc. Perhaps these losses reduce the most efficient 98% models to approximately 90%-95% depending on HVAC system type and configuration. A reasonable total building energy efficiency may range 38%-50% depending on the electric and thermal energy consumption ratios. In 1999, the education building sector consumed 257 trillion Btu’s of site electricity and 227 trillion Btu’s of natural gas. This generally inefficient use of fossil fuels to produce energy for buildings reflects a growing shift in the national energy philosophy. In recent years a national energy consciousness appears to be growing regarding our limited energy resources, our energy consumption levels, and our environment pollution levels. In 2001, President George Bush and his energy advisors released the administration’s National Energy Policy. President Bush stated, “America must have an energy policy that plans for the future, but meets the needs of our nation today. I believe we can develop our natural resources and protect our environment.” The first section of this report essentially summarizes the nation’s increasing energy consumption demand without adequately increasing generation capacity. This leaves an increasing gap in energy availability and thus creates increasing energy prices due to smaller generation/production supply. The U.S. Energy Information Administration (EIA) supports these conclusions with nationally collected data issued in the recently published 2004 Energy Outlook. Figure 3 highlights predicted trends in demand and prices by fuel and consumption type. With respect to the commercial building market, electric energy demand shall increase through 2025 and natural gas demand slightly decreases even though natural gas prices shall increase. The EIA predicts that new




generation station construction shall be required in the future years and that these new plants shall produce electricity primarily by coal combustion, a significant source of environment pollution due to the combustion emissions. However, the EIA predicts new generation plant construction will not occur for 10-15 years. In the interim, the EIA also predicts that Owners will employ smaller generation stations fueled primarily through natural gas and the mostly likely cost effective manner involves multiple generation engine plants that serve micro-grids such as city blocks. These smaller natural gas combustion engines reduce environment pollution through lower combustion product emissions and can support micro-grids until new generation plants are complete. The utility companies’ concerns over deteriorating electric infrastructure, power reliability issues as shown through the August 2003 Northeast blackout, and utility imposed brownouts force the Federal Government to consider alternative power production strategies. In the post 911 terrorism era, the idea of larger, but small quantity, generation stations presents a potential terrorism target that further questions reliability. Smaller, but higher quantity, generation engine plants increase the potential for reliability. A terrorism attack on one large generation station affects many customers, however a terrorism attack on one small generation station that feeds one small micro-grid affects few customers and minimally impacts the national grid. The Federal Government is currently considering investment in new utility grid infrastructure vs small generation plants that support micro-grids. Even the highly respected ASHRAE organization recognizes the problem. In February of 2004 the former vice president of ASHRAE echoed these concerns at a luncheon that Consulting Specifying Engineer magazine attended and reported. In his presentation, Mr. Kent Peterson stated, “We’re going to run out of fossil fuels in perhaps the next 40 to 50 years,…And in this country we really don’t pay the true cost of fuel, so it’s not as much of an issue as [it is] in Europe or Asia, but we have to have a broader awareness, a world perspective, of how much energy, as a nation, we consume….When the fuels begin to run out, the rise in energy costs will be dramatic with a very real potential of stopping the whole industrial engine that runs this country,…So we have a moral obligation to the world as a whole; it’s not just us consuming anymore. It’s China and a lot of other developing nations, and we have to consider what impact that’s having [on fuel depletion].” Mr. Peterson opened his presentation with the direct, attention grabbing statement, “It’s our goal to have buildings consume zero energy by 2020” (emphasis by this report author). Mr. Peterson boldly states an obligation and a goal that requires a revision in building energy consumption design strategies by all building design professionals. Appendix D contains excerpts of the previous discussions.




Data from

Chemical energy combustion creates harmfcitizens through respiratory problems andgreenhouse gases and overall environmentadecades, significantly revised pollution lawsdioxide (CO2) levels continue to grow, but and (SO2) and nitrogen oxide (NOx), combuPeterson’s comments remind design profesthat viewing buildings as total energy comaximizing energy conversion from combuand predicted trends from the EIA.

MECHANICAL OPTION PFC – DR. FREIHAUT 05APR04

Figure 3 www.eia.doe.gov

ul environment air pollution. This air pollution affects environment destruction. In an effort to reduce l air pollution, the Federal Government, in the last two

and regulations. As reported through the EIA, carbon the data shows significant reductions in sulfur dioxide stion products. As Owner’s continue construction, Mr.

sionals that utilizing efficient HVAC systems helps, but nsumers and polluters helps shift design focus to sted fuel. Figure 4 reflects pollution emission levels

JOHN JOSEPH SHAW SPRING 04 THESIS REPORT - 18 -



Figure 4 Data from www.eia.doe.gov

The Problem In summary and from a micro perspective, the Ohio School Facilities Commission constrains the facility HVAC system type to specific system configurations without detailing the heating and cooling plant type. The Ohio School Facilities Commission permits alternatives when detailed energy modeling and operating cost analysis is submitted for approval, but typical design professionals neglect pursuing this option due to additional project costs. Although indoor air quality measures are not maximized with the attention to relative humidity control (mold control) and maximum or strong air filtration (dust/particulate control), IAQ is reasonably addressed through minimum filtration, economizer cycle (building purge), and CO2 sensors. The nature of VAV-Reheat systems reasonably accommodates thermal comfort through proper air distribution and air temperature as well as utilize energy relative efficiently by reducing output as load reduces. Alternate systems such as water source heat pump systems as well as dedicated outdoor air systems (DOAS) are general HVAC system alternatives and relatively efficiently utilize the building incoming energy. Both alternatives, and others, offer excellent benefits and deserve consideration. However both require two fuel sources to meet cooling and heating needs and both require multiple smaller terminal units or radiant panels that generally have shorter equipment life cycles than central station air-handlers, utilized for the VAV w/reheat system. Therefore a macro perspective may produce results.




From the macro perspective, the revised National Energy Policy demands consideration of alternative energy systems that maximize building energy efficiency, defined as the total energy “input” (electric and thermal – secondary energy) per the total combustion fuel input (coal, natural gas etc) required to produce the secondary energy. The additional goals involve reducing the total national, fossil fuel energy demand relative to traditional building energy sources (grid and chemical), and reducing environment pollution emissions. A facility that incorporates the national energy policy ideology and implements strategies to meet these goals may result in lower fossil fuel energy consumption, lower fossil fuel demand and less environment pollution. This may result in lower operating costs, maintenance costs, and installation costs. A revised cooling and heating plant that rethinks how buildings use energy may deal with these issues reasonably. Proposed Solution of the Problem In order to address the global problem of reducing total fossil fuel energy demand, pollution emissions, operating cost, and possibly installation costs, Owners may consider integrating a trigeneration plant to substitute or integrate with the existing cooling/heating plant/utility grid. The ultimate goal involves maximizing the combusted fuel energy into useful alternate forms of energy. The choice of the combustion fuel also assists with pollution emissions reduction. Perhaps the strongest reason for considering this option involves power reliability and dependability, and use of waste heat for thermal energy needs. Public school facilities frequently become places of refuge during times of natural disaster or civic troubles. Facilities capable of producing self sustaining power and thermal energy reassures residents and promotes local community and government stability.

Cogeneration/Trigeneration Feasibility Introduction The term, Cogeneration, describes a process of converting chemical energy, through combustion, into two useful alternate energy forms. The combustion process occurs through a reciprocating engine, similar to the engine of a vehicle, or a turbine engine, similar to an airplane combustion turbine engine, without the noise. The engine spins a driveshaft that produces mechanical work and waste heat. The mechanical work drives an electric generator and the waste heat is collected and used as hot water or steam. Recovering waste heat and utilizing it for building energy needs increases the building energy efficiency as defined previously. In addition, the hot water or steam may be used to drive hot water or steam absorption chillers for cooling. When cooling becomes a third useful energy form, the term cogeneration changes to Trigeneration. Typically absorption chiller waste heat is dumped to the atmosphere through a cooling tower, however, this waste heat may be used for domestic hot water heating, through double wall heat exchangers before being dumped to the atmosphere in the cooling tower. The ultimate goal involves utilizing as much of the output energy as feasible for the amount of input energy. Due to low emissions, the preferred fuel choice involves natural gas, however other alternative fuels, such as biomass, methane, diesel, and others may be used. Figure 5 shows a possible trigeneration system idea.




Electricity production typically is integrated with the building distribution and may be used directly at the facility or “pushed” back into the utility grid by a step up transformer for use at overhead voltages. IEEE standard 1547 establishes guidelines for cogeneration system utility interconnections. The recent development of this standard clearly indicates a growing market, due to Owner’s who desire this form of building energy production for reliability, power quality, and utility price reduction reasons. However, Design Professionals must exercise strong communication with local utility representatives due to severe interconnection safety reasons. For example, if an Owner sells power from onsite cogeneration production back to the utility, several safety equipment and configurations must be installed prior to integrating with the electric utility grid. If the grid lost power, utility crews must have a way of repairing utility lines without risk of electrocution due to the Owner’s cogeneration system energizing the utility circuit.

Figure 5 - Trigeneration Simplified Schematic Source: Midwest CHP Application Center

Basis of Design The success of Cogeneration integration involves determining the current facility heating, cooling, electric load profiles, energy consumption, emissions performance, and economic factors such as equipment installation, operating and maintenance costs. Once determined, a Design Professional may select equipment to displace electrical utility demand and thermal needs. In addition, integration costs including equipment, installation, operating and maintenance costs may also be determined. Finally, a comparison of the proposed cogen system with the current facility heating and cooling plant equipment, costs, and emissions all normalized with national data may be determined. The National Perspective Nationally, education facilities occupy the lower median regarding electric and natural gas energy consumption. In 1999 (recent data unavailable), The Energy Information Administration (EIA) MECHANICAL OPTION JOHN JOSEPH SHAW PFC – DR. FREIHAUT SPRING 04 THESIS REPORT 05APR04 - 21 -



reports that educational facilities consumed 257 trillion btu’s of electricity and 227 trillion btu’s of natural gas (Figure 6). In 2003, the commercial building industry emitted 9.3metric tons of carbon dioxide by natural gas, 782.5metric tons of CO2 by electricity (utility grid production), and 195.8 metric tons of CO2 by coal. In 2002, 4.7 million tons of Nitrogen Oxide and 9.9 million tons of sulfur dioxide were released to the atmosphere (Figure 7). Although Federal regulations mandate reductions in NOx and SO2, and the annual discharge amounts reduce each year, the EIA predicts a continued growth in CO2 emissions.

Figure 6 - Electrical and Natural Gas Usage Summary Data from www.eia.doe.gov




Figure 6 – Pollution Emissions Data www.eia.doe.gov

Current Design Energy Profiles In order to determine the quantity and type of potential trigeneration equipment selection, load and energy modeling was conducted using Trane Trace700. The modeling establishes thermal and electrical demand, consumption, and economic data. The output results were exported into Microsoft Excel to use for analysis and establish graphical results. The results are profiled by monthly data lines for a typical 24 hour day. Both cooling and heating needs are consolidated into thermal (Btu/hr) units. The facility requires a maximum cooling capacity of approximately 650ton and a maximum heating demand of approximately 4000Mbh. Appendix E contains energy modeling results prints. The reader is reminded that education facilities have occupancy schedules that typically operate between 7am and 3pm, and 3pm till 11pm for sporting events, afterschool, and community center activities. Therefore the hours between 11pm and 7am reflect minimal demand to maintain lighting for janitorial services and HVAC night setback thermal and electrical demand. Figures 7-11 reflects occupancy schedules for a typical classroom, lunch, and evening day, electric monthly (Kw) demand, and monthly thermal (Btu/hr) demand profiles over a 24 hour time step. The occupancy schedules indicate a 25th hour that is an error in the chart formation. The report deadline prevented correction to this chart. Since the intent of trigeneration involves displacing the hourly electric and thermal demand, a thorough understanding of these profiles is required. The reader is reminded to review the existing plant summaries in the previous existing conditions section. Table 1 summarizes the maximum thermal and electrical demand and consumption values for the year. Table 2 summarizes monthly energy expenditures. Overall the facility spends approximately $176,555 per year on electric and natural gas. Cogeneration attempts to displace as much of these energy costs as feasible. The utility rate structures mentioned previously result in the costs listed below. The summer month natural gas costs reflect costs for the hot water reheat.




Table 1 - ELECTRICAL AND THERMAL MAX DEMAND/CONSUMPTION SUMMARY

ELEC Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec On-Pk Cons. (kWh)

64,563 58,183 78,004 74,560 112,705 96,782 99,563 96,215 95,200 79,871 63,294 61,123

Off-Pk Cons. (kWh)

70,999 62,745 54,594 43,686 59,508 58,770 78,010 54,484 53,271 47,576 57,978 69,511

On-Pk Demand

(kW) 374 375 373 461 716 901 926 781 700 486 404 374

On-Pk Cons. (kWh)

64,563 58,183 78,004 74,560 112,705 96,782 99,563 96,215 95,200 79,871 63,294 61,123

NG On-Pk Cons.

(therms) 5,793 5,290 3,932 981 838 909 918 951 736 1,160 1,788 4,820

On-Pk Demand

(therms/hr) 41 47 37 14 4 4 4 4 4 16 21 38

Building Energy Consumption = 75,077 Btu/(ft2-year) Total Kwh/of

fpk 980,062 Total Therm 28,116

Source Energy Consumption = 133,368 Btu/(ft2-year) Total Kwh/o

npk 711,132 Total Therm /hr 47

Total Kw 926 Floor Area =

114,330

ft2

Total Kwh 1,691,194

Total 600

Table 2 - ELECTRICAL AND THERMAL MAX DEMAND/CONSUMPTION SUMMARY ELEC Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

On-Pk Cons. ($) 4,049 3,654 4,775 5,049 7,598 6,497 6,613 6,255 6,420 4,862 3,973 3,850

On-Pk Demand

($) 4,557 4,572 4,540 5,575 9,408 11,794 12,044 10,385 9,209 4,809 4,019 3,735

Total ($): 8,606 8,226 9,315 10,625 17,006 18,291 18,657 16,640 15,629 9,671 7,992 7,586

On-Pk Cons. ($) 4,049 3,654 4,775 5,049 7,598 6,497 6,613 6,255 6,420 4,862 3,973 3,850

NG On-Pk

Cons. ($) 5,741 5,284 3,938 997 849 925 945 1,015 752 1,173 1,833 4,859

Elec Cons. ($) 63,596 Elec Demand ($) 84,647

Gas Cons. ($) 28,312 Total ($): 176,555

Floor Area (ft2)

114,330




TYPICAL CLASS/ADMIN OCCUPANCY SCHEDULE

00.10.20.30.40.50.60.70.80.9

1

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

HOUR

PER

CEN

TAGE

Jan-Dec Clg Dsn Heating Jan-May WkdyJun-Aug Wkdy Sep-Dec Wkdy Jan-Dec Sat-Sun

TYPICAL LUNCH OCCUPANCY SCHEDULE

00.10.20.30.40.50.60.70.80.9

1

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

HOUR

PERC

ENTA

GE


TYPICAL EVENING USE OCCUPANCY SCHEDULE

00.10.20.30.40.50.60.70.80.9

1

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

HOUR

PERC

ENTA

GE


Figure 7 - Occupancy Schedule Profiles




YEARLY DESIGN HOURLY KW DEMAND

0

100

200

300

400

500

600

700

800

900

1000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

HOUR

KW

JAN TOTAL KW DSN FEB TOTAL KW DSN MAR TOTAL KW DSN APR TOTAL KW DSNMAY TOTAL KW DSN JUN TOTAL KW DSN JUL TOTAL KW DSN AUG TOTAL KW DSNSEP TOTAL KW DSN OCT TOTAL KW DSN NOV TOTAL KW DSN DEC TOTAL KW DSN

YEARLY DESIGN THERMAL DEMAND

0

2000

4000

6000

8000

10000

12000

14000

16000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

HOUR

MBH

JAN TOTAL THERMAL MBH DSN FEB TOTAL THERMAL MBH DSN MAR TOTAL THERMAL MBH DSN APR TOTAL THERMAL MBH DSNMAY TOTAL THERMAL MBH DSN JUN TOTAL THERMAL MBH DSN JUL TOTAL THERMAL MBH DSN AUG TOTAL THERMAL MBH DSNSEP TOTAL THERMAL MBH DSN OCT TOTAL THERMAL MBH DSN NOV TOTAL THERMAL MBH DSN DEC TOTAL THERMAL MBH DSN

Figure 8 - Yearly Design Kw and Thermal Hourly Demand Profiles




YEARLY WEEKDAY KW DEMAND

0

100

200

300

400

500

600

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

HOUR

KW

JAN TOTAL KW WKDY FEB TOTAL KW WKDY MAR TOTAL KW WKDY APR TOTAL KW WKDYMAY TOTAL KW WKDY JUN TOTAL KW WKDY JUL TOTAL KW WKDY AUG TOTAL KW WKDYSEP TOTAL KW WKDY OCT TOTAL KW WKDY NOV TOTAL KW WKDY DEC TOTAL KW WKDY

YEARLY WEEKDAY THERMAL DEMAND

0

2000

4000

6000

8000

10000

12000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

HOUR

MBH

JAN TOTAL THERMAL MBH WKDY FEB TOTAL THERMAL MBH WKDY MAR TOTAL THERMAL MBH WKDYAPR TOTAL THERMAL MBH WKDY MAY TOTAL THERMAL MBH WKDY JUN TOTAL THERMAL MBH WKDYJUL TOTAL THERMAL MBH WKDY AUG TOTAL THERMAL MBH WKDY SEP TOTAL THERMAL MBH WKDYOCT TOTAL THERMAL MBH WKDY NOV TOTAL THERMAL MBH WKDY DEC TOTAL THERMAL MBH WKDY

Figure 9 - Yearly Weekday Kw and Thermal Hourly Demand Profiles




YEARLY SAT KW DEMAND

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

450.0

500.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

HOUR

KW

JAN TOTAL KW SAT FEB TOTAL KW SAT MAR TOTAL KW SAT APR TOTAL KW SATMAY TOTAL KW SAT JUN TOTAL KW SAT JUL TOTAL KW SAT AUG TOTAL KW SATSEP TOTAL KW SAT OCT TOTAL KW SAT NOV TOTAL KW SAT DEC TOTAL KW SAT

YEARLY SAT THERMAL DEMAND

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

HOUR

MBH

JAN TOTAL THERMAL MBH SAT FEB TOTAL THERMAL MBH SAT MAR TOTAL THERMAL MBH SAT APR TOTAL THERMAL MBH SATMAY TOTAL THERMAL MBH SAT JUN TOTAL THERMAL MBH SAT JUL TOTAL THERMAL MBH SAT AUG TOTAL THERMAL MBH SATSEP TOTAL THERMAL MBH SAT OCT TOTAL THERMAL MBH SAT NOV TOTAL THERMAL MBH SAT DEC TOTAL THERMAL MBH SAT

Figure 10 - Yearly Saturday Kw and Thermal Hourly Demand Profiles




YEARLY SUN KW DEMAND

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

450.0

500.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

HOUR

KW

JAN TOTAL KW SUN FEB TOTAL KW SUN MAR TOTAL KW SUN APR TOTAL KW SUNMAY TOTAL KW SUN JUN TOTAL KW SUN JUL TOTAL KW SUN AUG TOTAL KW SUNSEP TOTAL KW SUN OCT TOTAL KW SUN NOV TOTAL KW SUN DEC TOTAL KW SUN

YEARLY SUN THERMAL DEMAND

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

HOUR

MBH

JAN TOTAL THERMAL MBH SUN FEB TOTAL THERMAL MBH SUN MAR TOTAL THERMAL MBH SUN APR TOTAL THERMAL MBH SUNMAY TOTAL THERMAL MBH SUN JUN TOTAL THERMAL MBH SUN JUL TOTAL THERMAL MBH SUN AUG TOTAL THERMAL MBH SUNSEP TOTAL THERMAL MBH SUN OCT TOTAL THERMAL MBH SUN NOV TOTAL THERMAL MBH SUN DEC TOTAL THERMAL MBH SUN

Figure 11 - Yearly Sunday Kw and Thermal Hourly Demand Profiles




Economic factors such as central plant installation costs, operating costs, and maintenance costs were also entered into the energy model. The model was based on a 10 year finance period and declining balance payback schedule. Table 3 summarizes the economic factors including annual utility costs from Table 2. The costs specifically indicate the heating and cooling equipment and some supporting pipe, pump, insulation, infrastructure costs. The entire facility HVAC scope (all HVAC items and infrastructure) cost approximately $4.4 million.

Table 3 - ECONOMIC FACTORS Equip/Installed Energy

Op $ Maint

Chillers $285,000 Elec $148,243 2 units NG $28,312 Boilers $130,000 11 units Infrastructure $40,000 Total $455,000 $176,555 $4,000

Table 4 outlines the existing heating plant emissions from the natural gas fired boilers. These values establish the pollution from the current heating plant for purposes of comparison to the cogen pollution production. Natural gas with appropriate pollution cleaning devices release low quantities of pollutants. Dr. Freihaut provided assistance with the pollution calculations due to the combustion chemistry.

Table 4 – Existing Boiler Emission Performance Data Patterson-Kelly Model NM-2000

CO 302 ppm Equipment performance

Full output

Modulating output SO2 0 ppm Equipment performance

Full output

NOX 7 ppm Equipment performance

Full output

Quantity 11 Table 5 outlines the existing utility generating station emissions for a national utility grid serving the facility and a boiler plant emissions. The electric utility supplier is The Electric Illuminating Company. Dr. Freihaut provided assistance with the pollution calculations due to the combustion chemistry. The area served by the new high school contains 70.7% coal combustion and 29.3% nuclear. MECHANICAL OPTION JOHN JOSEPH SHAW PFC – DR. FREIHAUT SPRING 04 THESIS REPORT 05APR04 - 30 -



Table 5 - EXISTING ELECTRIC UTILITY GRID EMISSONS 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 Pollutantj /kWh %Indpendence OH Particulates SO2/kWh NOx/kWh CO2/kWh

70.7 7.78E-04 9.04E-03 5.24E-03 1.52E+00

0.0 0.00E+00 0.00E+00 0.00E+00 0.00E+00

0.0 0.00E+00 0.00E+00 0.00E+00 0.00E+00

29.3 0.00E+00 0.00E+00 0.00E+00 0.00E+00

0.0 0.00E+00 0.00E+00 0.00E+00 0.00E+00

100.0 7.78E-04 9.04E-03 5.24E-03 1.52E+00 Grid Kwh 1,691,194 1315.7lbs 15288.4lbs 8861.9lbs 2,570,614.9lbs

lbm Pollutantj /kWh US Gas Boiler

Particulates SO2/kWh NOx/kWh CO2/kWh 0.00E+00 0.00E+00 2.00E-05 5.20E-01

Boiler Therms

28,116 OR Kwh 8239986.2 0 0 5.6E-4lbs 14.56lbs Particulates SO2 NOx CO2 Total 1315.7lbs 15288.4lbs 8861.9 2,570,619.5lbs MECHANICAL OPTION JOHN JOSEPH SHAW PFC – DR. FREIHAUT SPRING 04 THESIS REPORT 05APR04 - 31 -



Proposed Trigeneration System Equipment Selection Strategy Mechanical The selection of trigeneration equipment depends on electric and thermal displacement strategies and the performance of the equipment. Cogeneration equipment involves two primary thermodynamic cycles, the top and bottom cycle. Top cycles produce electrical power with waste heat as the byproduct and bottom cycles produce more thermal energy (through waste heat) with electricity as the byproduct. Microturbine engines offer low maintenance, highly reliable, less part load tolerance equipment while reciprocating engines offer higher maintenance, moderately-highly reliable, more part load tolerance equipment. Therefore, a microturbine shall be selected to displace the building base electric and thermal load, and one reciprocating engine shall displace the energy demand between the normally occupied times of 7am-11pm. The utility grid shall remain connected to displace design day demand, one air cooled chiller and two hot water boilers shall remain. The cogeneration equipment can be controlled via DDC controls to energize based on time clock schedule or load demand. Based on the profiles shown previously, the Elliot Microturbines model 100 Kw CHP shall displace the building base load of 75-100Kw and varying thermal load of up to 500mbh. One Hess Microgen model 375 unit shall displace the normal occupancy demand as well as produce 1700Mbh thermal capacity. During heating season, the Hess thermal output provides 200° water into a common header as well as the Elliot unit for heating needs. This hot water supplies air-handler heating coils as well as air terminal reheat coils. Excess thermal energy may be exchanged with domestic water to meet shower and kitchen hot water needs although these calculations have not been completed. During Cooling season, the Elliot thermal output provides hot water for reheat and/domestic hot water and the Hess thermal output provides hot water to a Cention HW absorption chiller. The absorption chiller flowrate requires hot water from the two backup boilers in addition to the Hess Microgen unit. The absorption chiller rejected heat is dissipated either through the Century cooling tower or may be utilized for domestic hot water heating prior to discharge to the cooling tower. Showers, sink, and lavatory domestic hot water use may require up to 35gpm of 100°F water which is the inlet cooling tower water temperature. This heat may be exchanged through a double wall heat exchanger to avoid using the natural gas domestic water heater except for kitchen use. Figure 12 shows a diagram of the Hess reciprocating engine and the Cention hot water chiller. The equipment selection strategy involves only replacing one of the electric, air cooled chillers and replacing all of the boilers except two for backup or extra capacity needs. The boiler setpoints must be adjusted to provide the 200°F water. Appendix F contains equipment cut sheets. Please note that the cogeneration thermal output water temperatures can be altered to suit traditional HVAC system design with negligible performance impact.




YEARLY WEEKDAY KW DEMAND

100

200

300

400

500

600

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

HOUR

KW

PFC – DR. FREIHAUT SPRING 04 THESIS REPORT 05APR04 - 33 -

0

JAN TOTAL KW WKDY FEB TOTAL KW WKDY MAR TOTAL KW WKDY APR TOTAL KW WKDYMAY TOTAL KW WKDY JUN TOTAL KW WKDY JUL TOTAL KW WKDY AUG TOTAL KW WKDYSEP TOTAL KW WKDY OCT TOTAL KW WKDY NOV TOTAL KW WKDY DEC TOTAL KW WKDY

YEARLY WEEKDAY THERMAL DEMAND

0

2000

4000

6000

8000

10000

12000

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

HOUR

MBH

JAN TOTAL THERMAL MBH WKDY FEB TOTAL THERMAL MBH WKDY MAR TOTAL THERMAL MBH WKDYAPR TOTAL THERMAL MBH WKDY MAY TOTAL THERMAL MBH WKDY JUN TOTAL THERMAL MBH WKDYJUL TOTAL THERMAL MBH WKDY AUG TOTAL THERMAL MBH WKDY SEP TOTAL THERMAL MBH WKDYOCT TOTAL THERMAL MBH WKDY NOV TOTAL THERMAL MBH WKDY DEC TOTAL THERMAL MBH WKDY

Elliot Unit Base Load

Hess Microgen Unit

Elliot Unit Hess Microgen Unit Base Load

Weekday Kw and Thermal Hourly Demand Displacement Strategy

MECHANICAL OPTION JOHN JOSEPH SHAW



Figure – 12 Hess Reciprocating Engine and Cention Hot Water Chiller





































Electrical Each unit provides 480/277V, 3-phase power with power factor detection and correction components built in. IEEE standard 1547 outlines electric interconnection standards for integrating cogeneration systems with utility grid connections to buildings. Depending on cost effectiveness, Owner’s desire, and Design Professional’s recommendations, these systems may produce power for the building independently with the utility providing standby power, may produce power in parallel with a building utility connection (peak shaving etc), or may produce excess power for distribution back to the utility grid where the utility purchases the excess power. Electric utility companies typically desire power buy back options to produce at least 1MW of excess power. First the Owner must pay for an interconnection study conducted by the utility irregardless. Second, if the Owner desires to sell power back to the utility, the utility will only purchase the power at the utilities displaced cost. Most utilities only purchase the power at 1.5 cents/Kwh. In addition, the Owner must purchase a step up transformer in order to supply power at overhead distribution voltages. Larger cogen plants, 1MW-hundreds of MW’s, have generators that produce the required overhead voltages to minimize transformer costs. In this option, the Owner then provides a step down transformer for the Owner’s normal electrical needs. Therefore, utility buy back requirements, fees, and rates prevent small cogen systems from cost effectively utilizing this option. The thesis redesign involves a parallel interconnection with the cogen units providing the majority of the power and the utility remains actively connected (no automatic transfer switch) as reserve power for excess demand. In this manner, the IEEE standard and utility companies require overcurrent, over/under frequency, reverse power, under power, under/over voltage, synchronism check relays, and breaker protection for the incoming electric distribution and each cogen unit connection. This equipment including the required breaker protection may be purchased in cubicle switchgear that may be attached to the building main switchgear. The proposed cogeneration system connects schematically per figure 13.

Switchgear

Figure 13 – Utility Interconnection Requirements Source: AP Energy




Constructability Issues When installing and using the proposed cogen system for this facility, Owners, Design Professionals, and Contractors must be aware of several issues. First the proposed units are configured for indoor use, but have outdoor enclosure kits, and may be located in the current main boiler mechanical room. These units would displace the boiler battery footprint and provide easy electrical connection to the main switchgear. This minimizes additional pipe and conduit distribution. The indoor installation requires dedicated ductwork to outdoor air louvers for the combustion air. This ductwork could be routed near the existing air-handling unit outdoor air louvers. In addition the combustion exhaust ductwork could be routed near the displaced boiler batter exhaust ductwork. These units require concrete equipment pads and it is recommended that a diesel storage tank be installed to assist the cogen engine operation for the reciprocating type engines. The Elliot model occupies a footprint of 120”Lx36”Wx83”H high and weighs 4,000lbs. The Hess model occupies a footprint of 122”Lx46”Wx70”H and weighs 11,600lbs. Second, both units require 16 weeks lead time for delivery and with the optional sound reducing options; the units produce sound levels comparable or slightly less than typical central station air handlers. Cogeneration systems do require special permits that the Owner secures under Design Professional’s assistance. Third, due to their small size, both units typically would have maintenance performed by factory personnel under a maintenance contract with the Owner. The Elliot model has the following maintenance schedule:

The Hess unit has the following maintenance schedule

Hess Microgen (Maintenance schedule) Item Intervals

Initial inspections

Preventive Maintenance




As req’d

50hr 250hr 750hr 1500hr 3000hr 6000hr 12000hr 24000hr

Oil/filter --Oil filter $32.00 --oil 5gal x $4.50=$22.50 --labor

x x x x x x x x

Take Oil sample x x x x x x x x Inspect Air Filter x x x Replace Air Filter x x x x x Inspect belts/hoses x x x x x Replace Belts/hoses x x x x Inspect electrical connections x x x x x x x x x Inspect coolant x x x x x x Replace Coolant x x x Inspect plugs x x x Replace plugs x x x x x x As

req 50 250 750 1500 3000 6000 12000 24000

Check Racor x x x Replace Racor filter x x x x x x Ohm wires (record) x x Replace wires x x x x x x Compression Test x x x x x Retorque head bolts x x x x x Adjust valve lash x x x x x x Inspect Generator x x x x x Test Generator insulation And connections

x x x

Inspect Cview Connections x x x x x x x x Inspect Intercooler Chiller x x x x x x x Document fuel consumption As

req 50 250 750 1500 3000 6000 12000 24000

Document average exhaust temp x x x x x x x x Document emissions data x x x x x Inspect charging system x x x x x x x x Rebuild P-1 Pump x x x Inspect main breaker Contacts

x x x x x x x x

Clean unit x x x x x x x x x Flush dump radiator x x x Clean cabinet/generator windings with dry low pressure compressed air

x x x x

Install Catalyst converter x Clean/rotate catalyst x x x x x x Perform top end inspection x x x Perform bottom end inspection x x




Results In order to determine the success of the displaced energy, the fuel utilization efficiency must be determined. This is a simple, rule-of-thumb calculation procedure since complex modeling is required for true system performance evaluation. Sophisticated software models could not be acquired due to software Owners refusal for trademark protections. The following table outlines the calculation procedure and table 6 outlines the results summary for the proposed cogeneration equipment. The calculation procedure compares the cogen output with the current plant efficiency in order to determine the cogen operating efficiency and current design displaced energy savings. The calculations indicate a 35% total fuel savings compared to the current facility fuel consumption.

Figure 14 – Fuel Utilization Savings Calculation

Table 6 - FUEL UTILIZATION RESULTS SUMMARY Indv Output Total Output Total Input Quantity

Boiler EFFq 0.85 Kw Mbh Mbh Mbh Qeff Elec Gen EFFp 0.34

Elliot Sys 100 587 928.3 1235.51 1 0.48

EEFshp 0.52 Hess Sys 375 1900 3179.9 3831.2 1 0.50




EEF hp 0. Run Kwh c 82 Hours

EEFferc 0.57 1 868,800 8688 FUE 0.55 1 4732 8 87,250 S 0.35

Total Kwh 1,756,050 1,691,194

Calculated Fr el Energy Mod

Table 7 lis equipment costs, installation cos g co nance costs for the

roposed trigeneration system. One factor mentioned without any values includes the permits and ts ts, operatin sts, and mainte

pgrants columns. Cogeneration systems require special permits due to the energy production at the facility. These permits address electrical interconnection permits and combustion emission permits. Grants provide a means to reduce the obvious enormous first costs. The Federal government and State governments offer grant incentives for this and other alternate energy technologies. The thesis deadline prevented an investigation of the quantity and type of these grants to be included in this report, however, this is a real cost reduction method. In addition, natural gas suppliers may offer cogeneration utility rate reductions for the use of natural gas. This would further reduce the operating utility costs. Finally, continued manufacturing production, due to increased market demand, will also reduce equipment, installation, and maintenance costs. Governmental bodies and a growing market support this technology.

Table 7 - ECONOMIC FACTORS

Equip stalled Fuel Op $

aint ermits Grants In M P

Elliot $95,000 109/yr nnual $19,000 $ $13,945 $1,700 A ?

1 unit $12,000 12,000hrs

$21,000 rs 24,000h

Hess 00 $50,000 72/yr 100,816 ? $450,0 $ $ $4,364 Annual

1 unit

$9,803 12,000hrs

$18,887 4,000hrs 2

Cention Chiller 210,000 $50,000 $ $3,000

Cention 25,000 $11,000 Cooling Tower

$ $4,000

Elec CBreaker/Relays

ubicle incl avg

4

$65,000 Annual

for 12/2overhauls

Total $845,000 $130,000 $181 ? ? $74,754 Note: the over maintenance at 12k and 24k hrs were averaged run cycle to get the annual

cost. it r was estim the k profiles over their

The Hess Microgen un un hours ated from w .




Tab tes the particulate

ENERATON EQUIPMENT EMISSIONS

le 8 lists the emissions performance of the cogen system. The choice of natural gas eliminas and SO2 pollution.

Table 8 - TRIG

ELLIOT Quantity - 1 CO <1.56 lbs/MWhr (<41 ppm) NOx 1.49 lbs/MWhr (<24 ppm) < SO2 None

lbm Pol kWh Gas Turbine lutantj /

Particulates /kWh CO2/kWh SO2/kWh NOx

0.00E+00 0.00E+00 2.50E-04 1.75E+00 868,800 Kwh 0 0 217.2lbs 1,520,400 HESS O 0.15g/bhp-hr(<9 ppm) C < Quantity - 1 NOx <0.60g/bhr-hr(<84ppm)

SO2 None

lbm Pollutantj /kWhGas Recip Engine

Particulates O2/kWh SO2/kWh NOx/kWh C

0.00E+00 0.00E+00 6.25E-03 1.12E+00 887,250 Kwh 0 0 5501lbs 993,720lbs

Summary and Conclusion Although the building utiliz ore efficiently, the costs es the chemical energy combustion m

of installation initially appear to be a bassociated with this type ad investment at current prices. The cogen approach costs $1,334,714 while the current design costs $633,555. Initially, this type of investment would not experience a payback when compared to the existing system design. However, additional funding assistance through grants and reduced natural gas price incentives for cogeneration would reduce the total costs substantially. Due to the thesis deadline, these specific incentives were not able to be determined. In addition, given the predicted substantial increase in electric demand and limited generation station production capacity, electric utility rates will continue to escalate. The reader should refer to the electric demand and natural gas price predictions from the MECHANICAL OPTION JOHN JOSEPH SHAW PFC – DR. FREIHAUT SPRING 04 THESIS REPORT 05APR04 - 46 -



EIA shown in figure 3. As the cogen manufacturing development and growth continues, the equipment costs will also decrease further reducing the maintenance and operating costs. Philosophically, the cogen design strategy utilizes chemical energy more efficiently, reduces combustion product emissions and thus air pollution, and produces dependable, reliable energy at the facility. A cogeneration design strategy combined with other building energy conservation strategies may eventually reach Mr. Peterson’s goal of building zero energy additions to the national supply. Design strategies such as daylighting design, efficient lighting design, Dedicated Outdoor Air System (DOAS) with radiant heating and cooling, offer further energy demand reductions that result in smaller cogen equipment and lower costs. Another option particularly for the Independence, Ohio location, involves the installation of larger combustion turbine engines for the production of electricity to be sold back to the utility. Even at 1.5 cents/kw Owner’s may achieve reasonable future payback periods of 8-10 years given the current trends.

OVERALL SUMMARY Existing Proposed First Costs $455,0 sts $975,200 00 First Co

Plus 1 boilers f m th current design chiller & 2 ro e $170,000 Annual Maint

Costs aint $2,000 Annual M

Costs $74,754

Annual Elec Energy Costs

$148,243 for day

Annual Elec Energy Costs

Some design operation at minimum kw

Annual Gas Energy Costs

$28,312

fuel

$114,760 calculated from

the utilization savings

Grants TBD $633,555 $1,334,714 Non-Cogen

nergy 2% elec

al energy

tilization eutilization efficiency

383% therm

Cogen uefficiency

79%

Emissions Emissions Particulates 315.7lbs articulates 1 P 0 SO2 15288.4lbs SO2 0 NOx 8861.9lbs NOx 5,718.2lbs CO2 2,570,619.5lbs 14,120lbs CO2 2,5





Bibliography 1. FAQ sheet info and Independence Schools Superintendent “State of the Schools – 2001”. Additional info may be found at http://www.independence.k12.oh.us/construction/ 2. Small-Scale Cogeneration Handbook, Bernard F. Kolanowski, Farimont Press, 2000 3. ASHRAE Handbook of Fundamentals; Loads and Energy Modeling chapters. 4. ASHRAE Handbook of Systems; chapter 7 Cogeneration http://www.poweronsite.org/Tutorial/Cogeneration.htmhttp://www.microturbine.com/http://www.eere.energy.gov/der/microturbines/microturbines.htmlhttp://www.energy.ca.gov/distgen/equipment/microturbines/microturbines.htmlhttp://www.energy.rochester.edu/http://www.voccontrol.com/index.htmhttp://www.eere.energy.gov/buildings/components/hvac/cooling/absorption.cfmhttp://www.eia.doe.govhttp://www.rcgroup.it/main/triplo.html#tophttp://www.whitehouse.govhttp://www.adsorptionchiller.bigstep.com/homepage.html;$sessionid$I4MHMKYAAAORBTZENUFZPQWPERWRJPX0http://www.trigeneration.com U.S. National Energy Policy: http://www.whitehouse.gov/energy/ National Energy Information: http://www.eia.doe.gov http://www.doe.gov/engine/content.do http://www.eere.energy.govhttp://www.eia.doe.gov/emeu/efficiency/ee_report_html.htm Cogeneration: 5. Orlando, Joseph A, Cogeneration Design Guide, ASHRAE, 1996 This design guide, published by ASHRAE, discusses system types, modeling strategies, economic implications and feasibility strategies. It is the fundamental resource for spring 04 thesis. 6. Kolanowski, Bernard F., Small-scale Cogeneration Handbook, The Fairmont Press Additional resource for cogeneration. 7. Horloek, J.H., Cogeneration Combined Heat and Power (CHP), Krieger Publising Company, 1997



te.org/Tutorial/Cogeneration.htmhttp://www.poweronsi

http://www.energy.rochester.edu/cogen/

rigeneration: T http://www.trigeneration.com/http://www.bchp.org/index.htmlhttp://www.bchp.org/professional.htmlhttp://www.rcgroup.it/main/thestory.html#tophttp://www.rcgroup.it/main/triplo.html#top Absorption Chillers: 8. Dorgan, Chad B.; Leight, Steven P.; Dorgan, Charles E., Application Guide for Absorption

vered Heat, ASHRAE 1995

RAE, discusses the application of absorption chillers for use se

; Dorgan, Charles E., Application Guide for Chiller Heat

nter.org/TechProDemo/Gas_Technology/Absorption_Chillers.htm

aclablib/library.htmomponents/hvac/cooling/absorption.cfm

.com/generic3.html

Cooling/Refrigeration Using RecoThis design guide, published by ASHwith cogeneration systems that for trigeneration. It extends the use to two-stage chillers for u

s. with refrigeration system9. Dorgan, Chad B.; Leight, Steven P.Recovery, ASHRAE 1995 Energy conservation measures to effectively utilize chiller waste heat. hh

ttp://www.energysolutionscettp://www.cention.com/

http://www.rockyresearch.com/hvhttp://www.eere.energy.gov/buildings/chttp://www.adsorptionchiller.bigstep Micro-turbines 10. Stewart, Jr., William E., Combustion Turbine If combustion turbines are used as th

Inlet Air Cooling Systems, ASHRAE 1999 e prime mover in lieu of reciprocating engines, certain

g time. Combustion turbines like cool Therefore, in warm weather seasons,

d water from absorbers) prechill the inlet air.

operating strategies must be following to maximize operatinir. The increased air density aids the combustion process.a

precoolers (DX or chille http://www.microturbine.com/ http://www.utcpower.com/http://www.eere.energy.gov/der/microturbines/microturbines.html


http://www.independence.k12.oh.us/construction/

http://www.whitehouse.gov/energy/

http://www.whitehouse.gov/energy/



Appendices


Documents

THE PENNSYLVANIA STATE UNIVERSITY...The Trane Trace700 program was used to determine monthly energy profiles over the 24 hour time step for typical monthly weekday, weekend and design