refrigeration playbook: heat reclaim · pdf fileashrae american society of heating, ... the...
If you can't read please download the document
TRANSCRIPT
NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency & Renewable Energy Operated by the Alliance for Sustainable Energy, LLC
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.
Contract No. DE-AC36-08GO28308
Refrigeration Playbook: Heat Reclaim Optimizing Heat Rejection and Refrigeration Heat Reclaim for Supermarket Energy Conservation Chuck Reis, Eric Nelson, James Armer, and Tim Johnson CTA Architects Engineers Boise, Idaho
Adam Hirsch and Ian Doebber National Renewable Energy Laboratory Golden, Colorado
Technical Report NREL/TP-5500-63786 March 2015
NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency & Renewable Energy Operated by the Alliance for Sustainable Energy, LLC
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.
Contract No. DE-AC36-08GO28308
National Renewable Energy Laboratory 15013 Denver West Parkway Golden, CO 80401 303-275-3000 www.nrel.gov
Refrigeration Playbook: Heat Reclaim Optimizing Heat Rejection and Refrigeration Heat Reclaim for Supermarket Energy Conservation Chuck Reis, Eric Nelson, James Armer, and Tim Johnson CTA Architects Engineers Boise, Idaho
Adam Hirsch and Ian Doebber National Renewable Energy Laboratory Golden, Colorado
Prepared under Task No. ARCB1102 Prepared under Subcontract No. LEA-0-40383-01
Technical Report NREL/TP-5500-63786 March 2015
NOTICE
This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof.
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.
Available electronically at http://www.osti.gov/scitech
Available for a processing fee to U.S. Department of Energy and its contractors, in paper, from:
U.S. Department of Energy Office of Scientific and Technical Information P.O. Box 62 Oak Ridge, TN 37831-0062 phone: 865.576.8401 fax: 865.576.5728 email: mailto:[email protected]
Available for sale to the public, in paper, from:
U.S. Department of Commerce National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 phone: 800.553.6847 fax: 703.605.6900 email: [email protected] online ordering: http://www.ntis.gov/help/ordermethods.aspx
Cover Photos: (left to right) photo by Pat Corkery, NREL 16416, photo from SunEdison, NREL 17423, photo by Pat Corkery, NREL 16560, photo by Dennis Schroeder, NREL 17613, photo by Dean Armstrong, NREL 17436, photo by Pat Corkery, NREL 17721.
NREL prints on paper that contains recycled content.
http://www.osti.gov/scitechmailto:[email protected]:[email protected]://www.ntis.gov/help/ordermethods.aspx
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.
Acknowledgments Refrigeration Playbook: Heat Reclaim was developed as a joint effort between the National Renewable Energy Laboratory and CTA Architects Engineers. This project was made possible with American Recovery and Reinvestment Act of 2009 funds.
The authors would like to thank Arah Schuur and Glenn Schatz of the U.S. Department of Energy Building Technologies Office for their support and guidance and to acknowledge reviewers who provided helpful feedback during the development of the playbook, including Ren Anderson, Eigen Energy; Ryon Browning, CLEAResult; Harrison Horning, Delhaize; Ron Judkoff, National Renewable Energy Laboratory; K.C. Kolstad and Mike Saunders, Emerson Climate Technologies; Tom Land, U.S. Environmental Protection Agency; Dustin Lilya, DC Engineering; Dustin Searcy, Parker Hannefin Corporation; and Caleb Nelson, CTA Architects Engineers.
iii
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.
Abbreviations and Acronyms ASHRAE American Society of Heating, Refrigerating and Air-Conditioning
Engineers
ANSI American National Standards Institute
Btu British thermal unit
CBP Commercial Building Partnerships
CFM cubic feet per minute
db dry bulb
DOE U.S. Department of Energy
DSH desuperheat
effectiveness or efficiency value
EER energy efficiency ratio - Btu/W-h
EIR energy input ratio
EWT entering water temperature
GPM gallons per minute
HVAC heating, ventilation, and air-conditioning
in. inch
IP Imperial units
kW kilowatt
LAT leaving air temperature
LWT leaving water temperature
MAT mixed air temperature
NREL National Energy Renewable Laboratory
OAT outdoor air temperature
p-h pressure-enthalpy
PLR part-load ratio
iv
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.
ppm part per million
SI International System of Units, also referred to as metric units
SHW service hot water
THR total heat of rejection
TAB test adjust and balance
TC technical committee
TD temperature differential
U thermal transmittance - Btu/hft2F
UPS uninterruptible power supply
USGBC U. S. Green Building Council
W Watts
wb wet bulb
WSHP water-source heat pump
v
vi
This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.
Executive Summary Background This refrigeration playbook for optimizing heat rejection and refrigeration heat reclaim for supermarket energy conservation emerged from work done as part of the U.S. Department of Energys Commercial Building Partnerships (CBP) program. CBP was a public/private, cost-shared initiative that demonstrated cost-effective, replicable ways to achieve dramatic energy savings in commercial buildings. It aimed to reduce energy use by 50% in new construction and 30% in existing buildings compared with minimum code requirements or with pre-retrofit energy use. Building owners teamed with the U.S. Department of Energy, national laboratory staff, and private sector experts to explore and implement energy-saving ideas and strategies. These strategies were then applied to specific building projects that could be replicated across an organizations building portfolio and eventually across the commercial building market.
Much of the analysis presented here emerged from a CBP pilot retrofit of a 213,000-ft2 Walmart supercenter in Colorado in which waste heat reclaim was used to heat ventilation air for the grocery sales area. It saves almost 20,000 therms of natural gas per year. While the results support Walmarts 20% energy savings commitment under the Better Buildings Challenge, they are also applicable to the whole supermarket sector. This includes companies with commercial refrigeration, such as Target, Whole Foods Market, SUPERVALU, and the Defense Commissary Agency, that also participated in CBP.
While heat reclaim systems have been used in supermarkets for many years, their performance is not well understood. At the same time, recent legislation in some parts of the country, including California and Washington, requires refrigeration waste heat to be recovered in supermarkets that meet certain criteria. This makes the calculation of energy savings from heat reclaim strategies critical to many store designs. This guide attempts to demystify the energy savings associated with heat reclaim strategies by providing information and tools to help experienced refrigeration system designers make informed decisions that add value to a building design by reducing operating and life cycle costs.
Purpose The purpose of this playbook and accompanying spreadsheets is to generalize the detailed CBP analysis and to put tools in the hands of experienced refrigeration designers to evaluate multiple applications of refrigeration waste heat reclaim across the United States. Supermarkets with large portfolios of similar buildings can use these tools to assess the impact of large-scale implementation of heat reclaim systems. In addition, the playbook provides best practices for implementing heat reclaim systems to achieve the best long-term performance possible. It includes guidance on operations and maintenance as well as measurement and verification.
Scope This playbook was written with a traditional supermarket of 40,00060,000 ft2 in mind, but the concepts apply to smaller and larger facilities with commercial refrigeration systems. The concepts and methods do not provide a complete design or precise calculations for determining the energy savings associated with managing heat rejection. Long-term savings