Tubman African American Museum Christopher Champagne Mechanical Option 2003 Senior Thesis
Presentation Outline Presentation Goals Existing Conditions Existing Mechanical System Chiller Optimization Chilled Water Pumping Lighting of Gallery Space Conclusions and Recommendations Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Presentation Outline Presentation Goals Existing Conditions Existing Mechanical System Chiller Optimization Chilled Water Pumping Lighting of Gallery Space Conclusions and Recommendations Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Presentation Goals Investigation of the air-cooled water chillers: Museums have low load profiles during the evenings when • only the exhibit spaces or anywhere artwork is stored needs to be cooled. A smaller chiller for off-hours cooling and a larger one for • occupied mode. Staging of the chillers to see if an energy savings could be • realized. Investigation of switching from constant speed pumping to variable speed pumping: Advantages of primary-only, variable speed pumping. • Possibility of switching the chilled water pumps in this case. • Should the switch be made? • Investigation of current lighting system in gallery space Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Presentation Outline Presentation Goals Existing Conditions Existing Mechanical System Chiller Optimization Chilled Water Pumping Lighting of Gallery Space Conclusions and Recommendations Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Existing Conditions Location: Atlanta, GA Use: Museum Size: 45,000 ft 2 Two stories Construction Started: October 2001 Planned Completion: Spring 2004 Construction Cost: $15.5 million Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Design Team Architect E. Verner Johnson and Associates, Inc. CM/GC Harmon-Piedmont Construction, LLC M/E/P Vanderweil Engineers Structural Souza, True and Partners, Inc. Exhibit The PRD Group, Ltd Designer Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Presentation Outline Presentation Goals Existing Conditions Existing Mechanical System Chiller Optimization Chilled Water Pumping Lighting of Gallery Space Conclusions and Recommendations Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Existing Mechanical System (2) 121.5 ton HCFC-22 air-cooled water chillers (3) 290 GPM chilled water pumps (2) 25,000 CFM constant volume and (1) 18,000 CFM variable volume custom air handling unit. Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Chilled Water Equipment (2) Trane Air-Cooled Water Chillers 121.5 tons 290 GPM EWT = 55 ˚ F LWT = 45 ˚ F HCFC-22 Refrigerant Screw compressor (3) Bell & Gossett 1510 - 2 ½ BB Pumps 290 GPM 65 ft. head 1750 RPM 10.0 motor HP (1) Pump Standby Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Presentation Outline Presentation Goals Existing Conditions Existing Mechanical System Chiller Optimization Chilled Water Pumping Lighting of Gallery Space Conclusions and Recommendations Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Chiller Optimization Technique The maximum cooling load is 189.1 tons on July 15th at 2 pm using Atlanta Bin Data and Carrier’s Hourly Analysis Program (HAP). Engineering Equation Solver (EES) was used to simulate two equal size air-cooled chillers 1. Trane Air-Cooled Series R Rotary Liquid Chillers Model RTAA 125 (Design Capacity = 120.1 ton) 2. Trane RTAA 110 (Design Capacity = 108.5 ton) 3. Trane RTAA 100 (Design Capacity = 100.6 ton). Upper capacity that one chiller would run before the second chiller was run was varied from 85% to 100% of capacity to see which is the most efficient. The lower capacity at which the second chiller would turn off was set to 40%. Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Chiller Optimization Equations The optimization equations used in the EES simulation are from the California Energy Commission’s 2001 Non-Residential Alternative Calculation Methods (ACMs) document, specifically Chapter 2 entitled “Reference Method and Required Modeling Capabilities for Alternative Calculation Methods (ACMs).” The following three terms are functions of chilled water supply temperature (T chws ) and the outdoor dry-bulb temperature (T oa ). They are used to establish the efficiency of the chiller operation. CAP_FT is the full load capacity as a fraction of rated capacity. It is a capacity correction that is a function of those terms. EIR_FT is the full load efficiency (kW/ton) as fraction of rated capacity. It is an efficiency correction factor. EIR_FPLR is the fraction of full load power as a function of fraction of full load output. Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
EES Model Cases Case Model Ton kW Lower Upper Cap. (%) Cap. (%) A 125 120.1 120.1 40 90 B 110 108.5 108.5 40 90 C 100 100.6 113.6 40 90 D 125 120.1 120.1 40 85 E 110 108.5 108.5 40 85 F 100 100.6 113.6 40 85 G 125 120.1 120.1 40 95 H 110 108.5 108.5 40 95 I 100 100.6 113.6 40 95 J 125 120.1 120.1 40 100 K 110 108.5 108.5 40 100 L 100 100.6 113.6 40 100 Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Electrical Utility Rates The electricity would be provided by Georgia Power (a subsidiary of Southern Company). PLM-3 rate which is for small to medium building size. “Not less than 30 kW but less than 500 kW.” Base Charge (includes first 25 kWh or less $14.00 All consumption (kWh) not greater than 200 hours 200 hours times the billing demand. First 3,000 kWh 8.757¢ per kWh Next 7,000 kWh 8.026¢ per kWh Next 190,000 kWh 6.910¢ per kWh Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Annual Operating Cost and Time Operating Operating Operating Case AEC Cost Time Cost Time (kWh) ($) (hrs) Rankings Rankings A 1,033,188 88,572 13,618 6 4 B 1,043,601 89,291 14,339 9 8 C 1,038,866 88,964 15,014 8 11 D 1,096,997 92,981 14,034 10 6 E 1,108,762 93,794 14,762 12 9 F 1,104,441 93,495 15,350 11 12 G 977,400 84,717 13,136 4 2 H 985,828 85,299 13,966 5 5 I 1,038,866 88,964 14,907 7 10 J 927,718 81,284 12,670 1 1 K 934,654 81,763 13,583 3 3 L 929,304 81,393 14,121 2 7 Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Annual Operating Cost Annual Energy Cost 95,000 90,000 Cost ($) 85,000 80,000 75,000 1 A B C D E F G H I J K L Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Life Cycle Cost of Chillers The following formula from CoolTools was used in the calculation of the LCC. ( ) ( ) N ∑ ( ) = + + ÷ + j LCC FC UC MC 1 d j j = j 1 Where: FC = first cost of plant UCj = plant utility cost for year j MCj = relative maintenance cost for year j d = discount rate N = number of years of analysis Case Model Ton First Cost (FC) MCj = $500 A 125 120.1 $96,000 d = 12 % B 110 108.5 $84,000 N = 20 C 100 100.6 $75,000 Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Life Cycle Cost of Chillers LCC of Different Size Chillers $686,695.15 RTAA 100 Trane Model Number $698,458.84 RTAA 110 $706,880.98 RTAA 125 500,000.00 550,000.00 600,000.00 650,000.00 700,000.00 750,000.00 Cost ($) Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Chiller Optimization Recommendation The RTAA 100 has the smallest life cycle cost • based on the assumptions stated above. However given its tonnage being only slightly • above the design cooling load, this might not be a wise selection. The RTAA 110 would still provide cost savings • over the RTAA 125 (LCC savings = $10,422.14), along with some added safety to the designer. The staging should be set to 100% of capacity • of the first chiller before the second chiller is turned on. Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Presentation Outline Presentation Goals Existing Conditions Existing Mechanical System Chiller Optimization Chilled Water Pumping Lighting of Gallery Space Conclusions and Recommendations Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Chilled Water Pumping One method of saving energy used by a building is changing the primary pumps of a primary-only, chilled water system from constant speed to variable speed. Important Considerations: Does the chilled water system meets the requirements for being switched from constant speed to variable speed pumps? What is the overall economic benefit along with benefits that are not quantifiable? Christopher Champagne Tubman African American Museum Mechanical Option Atlanta, Georgia
Recommend
More recommend
