HomeMy WebLinkAboutNew Stuyahok Heat Recovery Preliminary Design Report - Jul 2017 - REF Grant 7060944New Stuyahok Teacher Housing
Waste Heat Reclamation
Preliminary Design Report
Prepared for:
Southwest Region School District
PO Box 90
Dillingham, AK 99576
Prepared by:
Stantec Architecture Inc.
725 East Fireweed Lane, Suite 200
Anchorage, AK 99503-2245
Project No: 2046064100
March 1, 2017
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Sign-off Sheet
This document entitled New Stuyahok Teacher Housing Waste Heat Reclamation was prepared by
Stantec Architecture Inc. (“Stantec”) for the account of Southwest Region School District (the
“Client”). Any reliance on this document by any third party is strictly prohibited. The material in it
reflects Stantec’s professional judgment in light of the scope, schedule and other limitations stated
in the document and in the contract between Stantec and the Client. The opinions in the
document are based on conditions and information existing at the time the document was
published and do not take into account any subsequent changes. In preparing the document,
Stantec did not verify information supplied to it by others. Any use which a third party makes of this
document is the responsibility of such third party. Such third party agrees that Stantec shall not be
responsible for costs or damages of any kind, if any, suffered by it or any other third party as a result
of decisions made or actions taken based on this document.
Prepared by
(signature)
Randall C. Wilkinson, P.E. ME 9859
Reviewed by
(signature)
(signature)
Mark Parrot
Approved by
(signature)
nsnnnsnnnnsnsnsnnsnnsssnsnsssnnnssnnsnnssnnsnnssnnnssnnnssnnnsnon, P.E. ME 9859
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NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
du rpt-prelim-design_new-stuyahok_heat recovery_20170301.docx i
Table of Contents
EXECUTIVE SUMMARY .................................................................................................................II
1.0 ASSUMPTIONS ...............................................................................................................1.1
1.1 WASTE HEAT AVAILABILITY...............................................................................................1.1
1.2 WASTE HEAT HARVESTING ...............................................................................................1.1
1.3 TEACHER HOUSING BUILDING HEATING LOADS ..........................................................1.1
2.0 DESIGN STRATEGY.........................................................................................................2.1
2.1 EQUIPMENT ENCLOSURE..................................................................................................2.1
2.2 HYDRONIC PUMPING AND FLUID SEPARATION ...........................................................2.1
2.3 BURIED PIPING CHOICES ................................................................................................. 2.1
3.0 DESIGN FEATURES .........................................................................................................3.1
3.1 SEPARATED FLUID SYSTEMS..............................................................................................3.1
3.2 EQUPMENT ENCLOSURE...................................................................................................3.1
3.3 AUTOMATIC GLYCOL FEED SYSTEM...............................................................................3.1
3.4 ENERGY METER..................................................................................................................3.1
4.0 OPERATIONAL RECOMMENDATIONS..........................................................................4.1
4.1 EXERCISE THE BOILERS REGULARLY ................................................................................4.1
LIST OF FIGURES
Figure 1 Rehau’s InsulPEX Uno and Duo System Comparison ..............................................2.2
LIST OF APPENDICES
DRAWINGS
OST ESTIMATE
RODUCT DATA
NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
ii
Executive Summary
The goals of this project are to design and install a system to harvest waste heat from the Village
of New Stuyahok’s electrical generators and to use this heat to provide first stage heating for
three teacher housing buildings near the New Stuyahok School. The generator plant owner, the
Alaska Village Electric Cooperative is planning to expand the generator plant, making more
heat available for harvest and re-use in the community.
As requested by the Southwest Region School District, Stantec Architecture Inc., has performed
preliminary engineering and product selection sufficient to determine a rough construction cost
estimate for this project.
Based on our findings, the project cost may be in the $400,000 to $500,000 range. Please see our
cost estimate for further details. Our cost estimate, which does include labor for installation. The
School District has indicated they may be inclined to install this entire system using their own staff
and local laborers. If the School District does perform their own installation, the installation cost
would be significantly lower.
Stantec Architecture Inc., made the fundamental assumption that the capacity of the heat
reclamation system is desired to match the heating capacity of the existing heating system in
the teacher housing buildings. This way, the entire heating requirements for the teacher housing
buildings would be met by harvested heat from the generator plant.
An economic analysis of the operational costs vs fuel savings associated with this project was
not included in this scope of work.
The School District would be wise to implement a program to exercise the Teacher Housing
buildings boilers on a regular basis so they do no fail or become unreliable due to neglect or
deferred maintenance. This is also needed to avoid stored fuel oil becoming stale. Stantec
recommends an exercise regime where at least one full tank of fuel oil is used each year. This
should exercise the boilers sufficiently and keep the stored fuel oil fresh.
du rpt-prelim-design_new-stuyahok_heat recovery_20170301.docx
NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
Assumptions
March 1, 2017
1.1
1.0 ASSUMPTIONS
The following are the most important assumptions used as the basis for our preliminary design.
1.1 WASTE HEAT AVAILABILITY
The owners and operators of the village generator plant, the Alaska Village Electric Cooperative
(AVEC) are willing and able to make the waste heat available for use by the Southwest Region
School District (School District).
1.2 WASTE HEAT HARVESTING
The School District wishes to harvest waste heat from the AVEC generator plant to the maximum
extent possible. This will be similar to the system designed by Stantec Architecture Inc. (Stantec)
and installed to provide waste heat reclamation for the school building.
1.3 TEACHER HOUSING BUILDING HEATING LOADS
Stantec did not perform any load calculations to determine the correct heating system size for
each of the three Teacher Housing buildings. It is assumed that the heating capacity of the
existing boiler in each building is the correct size. Waste heat systems shown in our designs will
be capable of providing the same heating capacity to these buildings as the existing boilers
currently provide. This assumes buried piping system heat losses are negligible compared to the
total heat load.
Each of the three building is equipped with a Weil-Mclain model WTGO-6 boiler with an output
capacity of 212,000 btu/hr. This boiler provides all heating for each of the apartments in the
building, as well as all domestic water heating.
NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
Assumptions
March 1, 2017
1.2
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NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
Design Strategy
March 1, 2017
2.1
2.0 DESIGN STRATEGY
The following are some of the most important decisions made as we prepared our preliminary
design.
2.1 EQUIPMENT ENCLOSURE
In anticipation of a lack of available space for new pumps and heat exchangers inside the
AVEC generator building, we have designed the system to fit inside of a small portable
equipment enclosure building. This building can be located where it is convenient for piping
connections and access.
2.2 HYDRONIC PUMPING AND FLUID SEPARATION
Two hydronic fluid pumping systems have been designed. One near the AVEC generator plant
to minimize the generator radiator fluid circulation. And one to circulate hydronic heating fluid
through the system of buried underground piping to the Teacher Housing buildings. Within the
teacher housing buildings, we are depending on the existing heating circulation pumps to
circulate the heating fluid to the various heating devices.
If a serious fluid system leak occurs in the buried underground piping system, it will not affect the
generator fluid system, or the building heating system fluid system.
2.3 BURIED PIPING CHOICES
In all cases, Stantec has prepared designs using pre-insulated PEX piping designed for buried
heating water service. We have assumed pre-insulated pipe from Rehau will be used. This piping
is manufactured in fairly long lengths and arrives in large spools. This makes installation easier
since fewer splices are required.
The ideal pipe size to carry the 636,000 btu/hr of waste heat to the Teacher Housing buildings is
3” diameter. This assumes the customary 20°F of temperature difference between the supply
and return pipes. The approximate distance of buried supply and return piping is 1,500 feet. To
use 3” diameter pipe, two separate pipes would be needed, one for supply, one for return.
Each has their own insulation and protective jacket pipe. Rehau calls this their InsulPEX Uno
piping system.
It may also be possible to use Rehau’s InsulPEX Duo system, which is manufactured with two
insulated pipes inside a single protective jacket pipe. See the illustration below for an example.
NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
Design Strategy
March 1, 2017
2.2
Figure 1 Rehau’s InsulPEX Uno and Duo System Comparison
The drawback to the Rehau InsulPEX Duo is that it has a maximum pipe size of 2-1/2-inch
diameter for each of the two pipes. This is too small to be ideal for this project. We may still be
able to use it if we could:
1. Use a greater than 20 degree F temperature difference, which would allow a reduced circulation flow
rate. Doing so would be unusual but still technically valid. The pumps and heat exchanger selections
would need to be changed.
-or-
2. Accept that the reclaimed heat may be inadequate to perform all of the necessary heating for the
Teacher Housing buildings. In peak winter months, the boilers may need to be operated to supplement
the reclaimed waste heat.
The advantage to using the Rehau InsulPEX Duo is significantly reduced material and installation
cost. The per foot cost of the pipe is only slightly higher for the Duo pipe, but it requires only
1,500 feet of pipe, instead of 3,000 feet that would be required if Uno pipe were to be used. We
estimate the cost savings for this project would be about $127,000 if InsulPEX Duo pipe is used.
NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
Design Features
March 1, 2017
3.1
3.0 DESIGN FEATURES
The following are the most important features and benefits of our design.
3.1 SEPARATED FLUID SYSTEMS
The buried piping system heat transfer fluid is completely separated from the generators and the
Teacher Housing building fluid systems. This helps ensure any malfunction of the waste heat
reclamation system will not impact any other system.
The existing Teacher Housing building heating systems will remain intact and fully functional. If for
any reason, the waste heat reclamation system is not working, the oil fired boilers in each
building can be switched on easily.
3.2 EQUPMENT ENCLOSURE
The primary heat exchanger and circulation pumps are located in a convenient equipment
enclosure where they are protected from weather and easily accessible for maintenance. The
equipment enclosure can be placed anywhere along the route of the buried piping.
We have indicated it be located near the generator building to minimize pipe lengths
connecting to the generators.
Another advantage of the small equipment enclosure is that it can be assembled and tested in
the School District Maintenance Shop prior to being brought to the site in New Stuyahok.
3.3 AUTOMATIC GLYCOL FEED SYSTEM
In case of a minor leak in the buried piping system, we have incorporated an automatic glycol
mixing tank and feed system. This will automatically replace any lost fluid with the correct
concentration of glycol and keep the system pressurized.
This glycol feed system can also send a warning through the digital controls system when the
glycol level is low, which would indicate a leak.
3.4 ENERGY METER
As required by AVEC, our design includes an energy meter. The energy meter can be used to
keep track of energy used to heat the Teacher Housing buildings. This type and brand of meter
is acceptable to AVEC. The meter is capable of remotely displaying the harvested energy, and
resetting the tally when necessary.
NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
Design Features
March 1, 2017
3.2
The energy meter reads the actual heat energy used to heat the Teacher Housing buildings,
along with some heat lost through the buried piping system.
NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
Operational Recommendations
March 1, 2017
4.1
4.0 OPERATIONAL RECOMMENDATIONS
4.1 EXERCISE THE BOILERS REGULARLY
It has been Stantec’s experience that exclusive use of waste heat to heat buildings may lead to
a situation where the waste heat is not available for some reason, and that the oil fired burners
will someday be needed. If the boilers have not been regularly exercised, they may fail or
become unreliable due to neglect or deferred maintenance. Also, it is beneficial to consume
the fuel oil in the storage tanks before it becomes stale. We would recommend an exercise
regime where at least one full tank of fuel oil is used each year. This should exercise the boilers
sufficiently and keep the stored fuel oil fresh.
NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
Operational Recommendations
March 1, 2017
4.2
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NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
APPENDIX A DRAWINGS
March 1, 2017
DRAWINGS
NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
APPENDIX A DRAWINGS
March 1, 2017
A.2
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1/25/2017 4:18:27 PMMECHANICAL ABBREVIATIONSMECHANICAL LEGENDAK
AFALTSTAE49THSPRELIMINARY
1/25/2017 4:18:27 PM
1/25/2017 4:18:27 PM
NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
APPENDIX B COST ESTIMATE
March 1, 2017
COST ESTIMATE
NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
APPENDIX B COST ESTIMATE
March 1, 2017
B.2
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Engineering Calculations
Date: 23-Feb-17
By: R. Wilkinson
Project:New Stuyahok Teacher Housing Waste Heat
Subject:50% level Construction Cost Estimate
Work Order: 2046064100
Revision: 2.0
Problem: Estimate construction cost
SW Region School District Feb 2017
Dillingham, AK Project Phase: 50% Submittal
Teacher Housing Waste Heat Reclaim SF (project):
Div Units Quantity Unit Cost Cost
Description
General
$0
Demolition
$0
Mechanical
3" InsulPEX Uno piping, materials only, incl. Shipping LF 3000 $80.00 $240,000
Trenching and backfill, shallow bury LF 1500 $25.00 $37,500
Pipe install labor LF 3000 $10.00 $30,000
3" x 2" branch taps, materials Only EA 4 $1,200.00 $4,800
Install labor EA 4 $1,000.00 $4,000
Equpment Enclosure, CAC Plastics 5x7, shipped EA 1 $15,000.00 $15,000
Anchors, installed EA 4 $200.00 $800
3" Piping from/to Generators LF 60 $41.00 $2,460
Valves, butterfly, installed EA 6 $675.00 $4,050
Pump PMP-1, 65 GPM @ 50', Vert close, 2 HP EA 1 $7,500.00 $7,500
Pump PMP-2, 65 GPM @ 90'. Vertical, close, 5 HP EA 1 $12,000.00 $12,000
Pump PMP-2, VFD EA 1 $3,000.00 $3,000
BTU Meter, Onicon, with sensors, installed EA 1 $5,000.00 $5,000
HX-1, larger, 636 MBH EA 1 $5,000.00 $5,000
HX-2,3,4, Smaller, 212 MBH, Brazed plate EA 3 $2,000.00 $6,000
Mount HX's and Connect to housing boilers EA 3 $5,000.00 $15,000
Circ loop temp control EA 1 $4,500.00 $4,500
Housing loop control modifications EA 3 $1,500.00 $4,500
Misc Valves, drains, thermometers, press guages LS 1 $5,000.00 $5,000
Expansion tank EA 1 $750.00 $750
Glycol Mix Tank EA 1 $2,000.00 $2,000
Glycol Fluid, 50% Propylene Glycol GAL 573.5 $10.00 $5,735
Subtotal: $414,595
General Conditions/Construction Costs/Mark-ups/Taxes
General Conditions and Contractor Costs (PM, Sup't, QAQC) % Project 5.00% $20,730
Mobilization/start up/Temp facilities % Project 1.50% $6,219
Bonds/Insurance -Allowance % Project 2.25% $9,328
Permitting and Plan Review Fees (Bldg, plan review, etc.) % Project 0.00% $0
ROW Permits/Fees N/A $0
Misc. Taps/Fees (water meter, water connections, fire line) N/A $0
Contractor Markup (OH&P) % Project 0.00% $0
Construction Escalation Factor @ 0.25% per month 2 Month 0.00% $0
Subtotal $36,277
Total - Estimated Construction Cost $450,872
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NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
APPENDIX C PRODUCT DATA
March 1, 2017
PRODUCT DATA
NEW STUYAHOK TEACHER HOUSING
WASTE HEAT RECLAMATION
APPENDIX C PRODUCT DATA
March 1, 2017
C.2
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100100909080807070606050504040303020201010000 25 50 75 100 125 150 175 200 225 250FLOW IN GALLONS PER MINUTEL/SEC 5 10 15NPSHR (ft)EFFICIENCY %BHP543210100806040200HEAD IN FEET7.20"7.50"5.50"BHP: 1.59NPSH: 2.1 ftEFF: 52%KV2007 1750 RPMPropylene Glycol 50% @ 180 65 gpm, 50' headImpeller Diam. 7.20"Size 2 x 2 x 7.0
1500 North Belcher Road, Clearwater, FL 33765 • Tel (727) 447-6140 • Fax (727) 442-5699
www.onicon.com • sales@onicon.com0569-3 08-13
ITEM # DESCRIPTION
SYSTEM-10-BAC System-10 BTU Meter, BACnet Compatible
SYSTEM-10-OPT8 High temperature sensors (over 200°F)
SYSTEM-10-OPT9 Add one analog output
SYSTEM-10-OPT10 Add four analog outputs
Choose from the following commonly used
thermowell installation kits:
SYSTEM-10-OPT4 Upgrade to outdoor thermowells (pair)
BTU-ST-INSTL32 Brass kit for welded steel pipe (¾" - 5")
BTU-ST-INSTL52 Brass kit for threaded steel pipe (¾" - 2½")
BTU-ST-INSTL34 SS kit for welded steel pipe (¾" and up)
BTU-ST-INSTL36 Brass kit for copper tube (¾" - 2")
BTU-ST-INSTL37 Brass kit for copper tube (2½" - 3")
F-1100/F-1200 Insertion Turbine Flow Meter (1¼” - 72”)
F-1300 Inline Turbine Flow Meter (¾” - 1”)
F-3000 Series Inline Electromagnetic Flow Meter (¼” - 48”)
F-3500 Insertion Electromagnetic Flow Meter (3”- 72”)
F-4200 Clamp-on Ultrasonic Flow Meter (½” - 48”)
F-2000 Series Inline Vortex Flow Meter (½” - 12”)
Consult with ONICON for additional thermowell
• SYSTEM-10-BAC BTU METER •
BACnet/IP COMPATIBLE
PROCESS CONTROL EQUIPMENT
3GF5
1500 North Belcher Road, Clearwater, FL 33765 • Tel (727) 447-6140 • Fax (727) 442-5699
www.onicon.com • sales@onicon.com0569-3 08-13
Name BACnet
Object Type
Units
Total Energy Analog Value Btu, kW-hrs or ton-hrs
Energy Rate Analog Input Btu/hr, kW or tons
Total Flow Analog Value gallons, liters or meters
3
Flow Rate Analog Input gpm, gph, mgd, l/s, l/m,
l/hr or m3/hr
Supply Temperature Analog Input °F or °C
Return Temperature Analog Input °F or °C
Energy Total Reset Binary Value Not applicable
Flow Total Reset Binary Value Not applicable
Auxiliary Input Total Analog Value Pulse Accumulator
Auxiliary Input Reset Binary Value Not Applicable
Consult with ONICON for additional
Heat Exchanger
SCROLL RESET PROGRAM
BTU X 10,000
ONICON insertion
flow meter
24 VAC input
BACnet Communications
to Control System
BACnet/IP
Supply TempSensor
Return TempSensor
Supply
Return
POWER
SYSTEM-10
BTU METER
TYPICAL SYSTEM-10-BAC-IP INSTALLATION
Hot Tap
Adapter
APPLICATION LOCATION & PIPE SIZE MODEL (SIGNAL TYPE) REQUIRED OPTIONS DISPLAY
HVAC APPLICATIONS
Chilled Water
Hot Water (280 F)
Condenser Water
(closed loop)
¾” -1” (0.8 to 38 gpm) F-1310 (analog)* None
System-10
1 ¼” - 2” F-1110 (analog)
316 SS for HW over 250 F
316 SS for non-metallic pipe
required features.
(long pipe runs)F-1110 (analog)
2 ½” and up with undeveloped F-1210 (analog)
Primary/Secondary
Thermal Storage
Any bi-directional application in
2 ½” and larger pipes FB-1200 (analog) D-100
Make-up Water
Domestic Hot Water
Domestic Cold Water
1 ¼” - 2” F-1130 (pulse)316 SS wetted metal
components are required for
insertion type meters in these
applications.D-100
Choose single or dual based on
straight pipe run F-1130 or F-1230 (pulse)
Steam Condensate Typically small pipes F-1130 or F-1330 (pulse)
316 SS wetted metal
components are required for
insertion type meters in these
applications.
Boiler Feed Water
(to 280 F)Typically small pipes F-1130 (pulse)
MUNICIPAL WATER
Municipal Water (long pipe runs)F-1111 (iso-analog)316 SS wetted metal
components required.D-1002 ½” and up with undeveloped F-1211 (iso-analog)
PROCESS APPLICATIONS
Process Water
Process Cooling
1 ¼” - 2” F-1111 (iso-analog)
316 SS wetted metal
components typically required.
D-100
(long pipe runs)F-1111 (iso-analog)
2 ½” and up with undeveloped F-1211 (iso-analog)
Process Cooling Low
Conductivity (long pipe runs)F-1111 (iso-analog)
Requires 316 SS welded
construction and low conductivity
option.
System-10 D-100 D-1200
* F-1300 series are inline turbine meters.
0468-3 07-12