The Cost of Using 1970

1

• The Cost of Using 1970s Era
• Design Concepts and FEARin
• Chilled Water Systems

Presented By Hemant Mehta, P.E.
WMGroup Engineers, P.C.
2
What is the FEAR

• No change in design as previous design had no
  complains from client
• No complain because no bench mark exists
• Fear to take the first step to change the
  concepts to use state of the art technology
• Consultants sell time. Fear is any new concept
  will take lots of time and it is not worth the
  effort

3
What are1970s EraDesign Concepts?

• System Design for Peak load only
• Primary/Secondary/Tertiary Pumping
• 5C (42F) supply temperature
• System Balancing
• Circuit Setters
• Band Aid solution for any Problem
• Projected Demand way above reality
• Oversized chiller, pumps TDH and everything else
  to cover behind

4
State of the Art Plant concepts

• Plant designed for optimum operation for the
  year. Peak hours are less than 200 hours a year
• Variable flow primary pumping system
• 3.3C (38F) or lower supply temperature
• No System Balancing. Balancing is for a static
  system.
• No Delta P valves No Circuit Setters
• No Band Aid solution for any Problem
• Use chilled water system diversity (0.63) to
  Project Cooling Demand
• The total Chilled water pumping TDH even for a
  very large system should not be more 63
  meters(than 200 feet)

5
Selecting Equipment to Optimize Efficiency

• Chiller equipment is often erroneously selected
  based on peak load efficiency.
• Peak load only occurs for a small number of hours
  of the year, as shown on the load duration curve
  below

6
The Design of the Human Body
Lungs(Chillers)
Brain (Building End-Users)
Heart (Variable Volume Primary Pump)
7
Basic 1970s Era Chiller Plant Design
Decoupler Line
Building Loads
Chiller
Primary Pump
Secondary Pump
8
Current Design Used on Many Large District
Chilled Water Systems
Chiller
Energy Transfer Station
Decoupler Line
Building Loads
Primary Pump
Secondary Pump
Building Pump
9
Modern Variable Volume Primary Chiller Plant
Design
Building Loads
Chiller
Variable Speed Primary Pump
10
Lost Chiller Capacity Due to Poor ?T
Ideal Design Conditions
150 L/sec (2,400 gpm)
150 L/sec (2,400 gpm)
13C (55.5F)
13C (55.5F)
No Flow Through Decoupler
5C (41F)
5C (41F)
150 L/sec (2,400 gpm)
150 L/sec (2,400 gpm)
Chiller sees a ?T of 8C (14.5F) at a flow of
150 L/sec (2,400 gpm) The chiller capacity is
therefore 5,000 kW (1,450 tons)
11
Lost Chiller Capacity Due to Poor ?T
Case 1 Mixing Through Decoupler Line
75 L/sec (1,200 gpm)
150 L/sec (2,400 gpm)
9C (48.25F)
13C (55.5F)
75 L/sec (1,200 gpm) at 5C (41F)
5C (41F)
5C (41F)
75 L/sec (1,200 gpm)
150 L/sec (2,400 gpm)
Chiller sees a ?T of 4C (7.25F) at a flow of
150 L/sec (2,400 gpm) The chiller capacity is
therefore 2,500 kW (725 tons)
12
Lost Chiller Capacity Due to Poor ?T
Case 2 Poor Building Return Temperature
150 L/sec (2,400 gpm)
150 L/sec (2,400 gpm)
9C (48.25F)
9C (48.25F)
No Flow Through Decoupler
5C (41F)
5C (41F)
150 L/sec (2,400 gpm)
150 L/sec (2,400 gpm)
Chiller sees a ?T of 4C (7.25F) at a flow of
150 L/sec (2,400 gpm) The chiller capacity is
therefore 2,500 kW (725 tons)
13
Small Loss in ?T Rapidly ReducesChiller Capacity
Assuming a design ?T of 8C (14.4F)
System ?T Chiller Capacity
8.0C (14.4F) 100
7.5C (13.5F) 94
7.0C (12.6F) 88
6.5C (11.7F) 81
6.0C (10.8F) 75
5.5C (9.9F) 69
5.0C (9.0F) 63
4.5C (8.1F) 56
4.0C (7.2F) 50
14
Technical Paper by Erwin Hanson(Pioneer in
Chilled Water System Design)
8C
9C
11C
15
Billing Algorithm for Buildings to Give Incentive
to Owners to Improve ?T

• Adjusted Demand Cost
• Adjusted Consumption Cost
• Total Cost Demand Consumption

Total Site Demand Cost X Bldg ton-hrs Total ton-hrs X Cost Penalty Factor
Total Site Electric Cost - Total Adjusted Bldg Demand Cost X Bldg ton-hrs Total ton-hrs
16
The Design of the Human Body
Lungs(Chillers)
Brain (Building End-Users)
Heart (Variable Volume Primary Pump)
17
History of Variable Primary Flow Projects

• King Saud University - Riyadh (1977)
• Louisville Medical Center (1984)
• Yale University(1988)
• Harvard University (1990)
• MIT(1993)
• Amgen (2001)
• New York-Presbyterian Hospital (2002)
• Pennsylvania State Capitol Complex (2005)
• Duke University (2006)
• NYU Medical Center (2007)
• Memorial Sloan-Kettering Cancer Center (2007)

18
King Saud University Riyadh (1977)

• 60,000 ton capacity with 30,000 tons for first
  phase
• Six 5,000 ton Carrier DA chillers
• Seven 10,000 GPM 240 TDH constant speed pumps
• Major Problem Too much head on chilled water
  pumps
• Lesson Learned Be realistic in predicting growth

19
Louisville Medical Center (1984)

• Existing system (1984)
• Primary/Secondary/Tertiary with 13,000 ton
  capacity
• Current System (2007)
• 120 feet TDH constant speed primary pumps with
  building booster pumps 30,000 ton capacity
• Changed the heads on some of the evaporator
  shells to change number of passes
• Primary pumps are turned OFF during winter, Early
  Spring and Late Fall. Building booster pumps are
  operated to maintain flow.

20
Yale University (1988)

• Existing system (1988)
• Primary/Secondary/Tertiary with 10,500 ton
  capacity
• Current System (2007)
• 180 feet TDH VFD / Steam Turbine driven variable
  flow primary pumps 25,000 ton capacity
• Changed the heads on some of the evaporator
  shells to change number of passes

21
Amgen (2001)

• Creation of a computerized hydraulic model of the
  existing chilled water plant and distribution
  system
• Identification of bottlenecks in system flow
• Evaluation of existing capacity for present and
  future loads
• Two plants interconnected Single plant operation
  for most of the year, second plant used for
  peaking
• Annual Energy Cost Savings 500,000

22
Additional Variable Primary Flow Projects

• Harvard University (1990)
• MIT(1993)
• New York-Presbyterian Hospital (2002)
• Pennsylvania State Capitol Complex (2005)
• Duke University (2006)
• NYU Medical Center (2007)
• Memorial Sloan-Kettering Cancer Center (2007)

23
Duke University Background

• CCWP-1 plant was built four years ago
• CCWP-2 design was 90 complete (Primary/Secondary
  pumping)
• We were retained by Duke to peer review the
  design
• Peer review was time sensitive
• Plant design for CCWP-2 was modified to Variable
  Primary pumping based on our recommendations

24
Duke CCWP-1 Before
25
Duke CCWP-1 After

• Dark blue pipe replaces old primary pumps

26
Duke CIEMAS Building CHW System
90 closed
Triple duty valves 50 closed
27
Duke CIEMAS Building AHU-9
Balancing valve 50 closed
28
NYU Medical Center (2007)

• Plant survey and hydraulic model indicated
  unnecessary pumps
• 1,300 horsepower of pumps are being removed,
  including 11 pumps in two brand new chiller
  plants
• 300,000 implementation cost
• 460,000 annual energy savings

29
NYU Medical Center (2007)

• Plant survey and hydraulic model indicated
  unnecessary pumps
• 1,300 horsepower of pumps are being removed,
  including 11 pumps in two brand new chiller
  plants
• 300,000 implementation cost
• 460,000 annual energy savings

8 Pumps Removed
3 Pumps Removed
7 Pumps Removed
3 Pumps Removed
30
Memorial Sloan-Kettering - Before
31
Memorial Sloan-Kettering - After
Bypass or removal of pump
Bypass or removal of pumps
32
Pump Cemetery
To date we have removed several hundred large
pumps from our clients chilled water systems
33
Plant Capacity Analysis -Detailed System Analysis
is a Necessity

• Modern computer software allows more complex
  modeling of system loads, which has proven to be
  very valuable to optimize performance and
  minimize cost.
• Return on investment to the client for detailed
  analysis is typically very high.

34
New York Presbyterian Hospital

• Applied revolutionary control logic

Log Data
35
Bristol-Myers Squibb

• Biochemistry research building
• 140,000 square feet
• AHU-1 (applied new control logic)
• 100,000CFM
• AHU-2 (existing control logic remained)
• 100,000 CFM

36
Bristol-Myers Squibb

• Applied revolutionary control logic

37
PA State Capitol Complex CHW ?T
38
South Nassau Hospital CHW ?T
39
Good Engineers Always Ask Why?

• Why does the industry keep installing
  Primary/Secondary systems?
• Why dont we get the desired system ?T?
• Why does the industry allow mixing of supply and
  return water?

40
Good Engineers Always Ask Why?

• Why does the industry keep installing
  Primary/Secondary systems?
• Why dont we get the desired system ?T?
• Why does the industry allow mixing of supply and
  return water?
• Answer To keep consultants like us busy!
• Why change?

41
Reasons to Change

• The technology has changed
• Chiller manufacturing industry supports the
  concepts of Variable Primary Flow
• Evaporator flow can vary over a large range
• Precise controls provides high Delta T

42
Change is Starting Around the World

• Most of the large district cooling plants in
  Dubai currently use Primary/Secondary pumping
• By educating the client we were able to convince
  them that this is not necessary
• We are now currently designing three 40,000 ton
  chiller plants in Abu Dhabi using Variable
  Primary Flow as part of a 6.9 billion
  development project

43
Summary

• There are many chilled water plants with
  significant opportunities for improvement
• WM Group has a proven record of providing smart
  solutions that work
• We will be happy to review your plant logs with
  no obligation

44

• Thank You
• Hemant Mehta, P.E.
• President
• WMGroup Engineers, P.C.
• [phone]
• hmehta_at_wmgroupeng.com

45
The New Royal Project Central Energy Plant
Study By
September 16, 2008
46
Project Objective

• Determine the Optimum Central Energy Plant
  Configuration and Cogeneration Feasibility

47
The New Royal Project

• A new tertiary hospital for the region
• 95,000 m2 initial area (basis of analysis)
• Disaster Recovery Consideration
• N1
• Onsite Power Generation (/- 70 of peak demand)
• Two separate central plants

48
Project Site
49
Typical Utility Tunnel
50
Study Approach

• Developing load profiles for Heating, Cooling and
  Power
• Developing and screening of Options
• Creating a computer model for energy cost
  estimate
• Performing Lifecycle Cost Analysis
• Performing Sensitivity Analysis
• Conclusions

51
Load Profiles

• Cooling/Heating Daily peaks provided by Bassett
• Cooling 7,400 kWt (2,100 RT)
• Heating 8,000 kWt
• Power Daily peaks provided by Bassett
• Peak demand 4,500 kWe
• Min. demand 1,400 kWe

52
Cooling Loads
53
Daily Cooling Load Profile
54
3-D Cooling Load Profile
55
Cooling Load Duration Curve
607 Equivalent Full-Load Hours
56
Heating Loads
57
Daily Heating Load Profile
58
3-D Heating Load Profile
59
Heating Load Duration Curve
1,742 Equivalent Full-Load Hours
60
Electric Loads
61
Daily Electrical Load Profile
62
3-D Electrical Load Profile
63
Utility Rates

• Natural Gas 9.00 / GJ
• Electricity (taken from hospital bill)
• Demand Charge 0.265641 per kVA per day
• Based on contracted annual demand
• About 10.00 per kW per month
• Energy Charge
• 0.14618 / kWh (on-peak, 7 am to 10 pm)
• 0.05322 / kWh (off-peak, 10 pm to 7 am and
  weekends)
• Fixed Charges 27.7155 per day
• About 830 per month

64
Base Option Considerations

• Minimum first cost
• Two locations
• Conventional equipment
• Electric chillers
• Gas-fired boilers
• Diesel emergency generators
• No cogeneration or thermal storage
• Operational efficiency and reliability

65
Central Energy Plant Base Option
Plant Component East CEP West CEP
Chiller Plant (2) 2,500 kWt electric motor driven, water-cooled chillers (2) 2,500 kWt electric motor driven, water-cooled chillers
Boiler Plant (2) 2,750 kWt fire tube boilers producing hot water (2) 2,750 kWt fire tube boilers producing hot water
Thermal Storage None None
Power Generation (1) 2,000 kVA diesel generator (emergency power) (1) 2,000 kVA diesel generator (emergency power)
66
Alternative Plant Considerations

• Non-Electric Chillers
• Absorption Chillers (with or without heaters)
• Steam Turbine Driven Chillers
• Gas Engine Driven Chillers
• Thermal Storage
• Ice Storage
• Chilled Water Storage
• Cogeneration
• Geothermal

67
Electric vs. Non-Electric Chillers
Sample taken from another project
68
Hybrid Plant Option 1A
Plant Component East CEP West CEP
Chiller Plant (1) 2,650 kWt electric motor driven, water-cooled chiller (1) 2,450 kWt direct-fired absorption chiller/heater (1) 2,650 kWt electric motor driven, water-cooled chiller (1) 2,450 kWt direct-fired absorption chiller/heater
Boiler Plant (2) 1,750 kWt fire tube boilers producing hot water (1) 1,500 kWt direct-fired absorption chiller/heater (same unit as above) (2) 1,750 kWt fire tube boilers producing hot water (1) 1,500 kWt direct-fired absorption chiller/heater (same unit as above)
Thermal Storage None None
Power Generation (1) 2,000 kVA diesel generator (emergency power) (1) 2,000 kVA diesel generator (emergency power)
69
Ice Storage vs. Chilled Water Storage

• Advantages of ice storage
• Ice storage requires less space
• Suitable for low temperature operation
• Disadvantages of ice storage
• Ice generation requires more energy
• Ice storage system has a higher first cost
• Ice storage is not considered for this project

70
Thermal Storage Option 2
Plant Component East CEP West CEP
Chiller Plant (2) 1,750 kWt electric motor driven, water-cooled chillers (2) 1,750 kWt electric motor driven, water-cooled chillers
Boiler Plant (2) 2,750 kWt fire tube boilers producing hot water (2) 2,750 kWt fire tube boilers producing hot water
Thermal Storage (1) 30,000 kWt-hr chilled water storage tank connected to site chilled water distribution system (1) 30,000 kWt-hr chilled water storage tank connected to site chilled water distribution system
Power Generation (1) 2,000 kVA diesel generator (emergency power) (1) 2,000 kVA diesel generator (emergency power)
71
Cogeneration Alternatives
System Application Assessment
Reciprocating Engines Suitable for high electric but low thermal loads such as NRP.
Fuel Cells Emerging technology not for commercial use.
Microturbines Limited capacity of units and requires skilled labor.
High Pressure Steam Boiler and Back Pressure Turbine No steam required by NRP.
High Pressure Steam Boiler and Condensing Turbine No steam required by NRP.
Gas Turbine with HRSG Typically for larger installations, requires skilled operators, and possible emissions treatment issues.
Combined Cycle Generation Typically for larger installations, requires skilled operators, and possible emissions treatment issues.
72
Engine Generator Topping Cycle
73
Option 3 Cogen w/ Gas Engines
Plant Component East CEP West CEP
Chiller Plant (2) 1,750 kWt electric motor driven, water-cooled chillers (1) 1,140 kWt hot water-fired absorption chiller (2) 1,750 kWt electric motor driven, water-cooled chillers (1) 1,140 kWt hot water-fired absorption chiller
Boiler Plant (2) 1,750 kWt fire tube boilers producing hot water (2) 1,750 kWt fire tube boilers producing hot water
Thermal Storage None None
Power Generation (1) 2,000 kVA natural gas generator (cogeneration) (1) 2,000 kVA diesel generator (emergency power) (1) 2,000 kVA natural gas generator (cogeneration) (1) 2,000 kVA diesel generator (emergency power)
Diesel generators not required if onsite LNG
storage is provided
74
Option 4 Cogen Thermal Storage
Plant Component East CEP West CEP
Chiller Plant (2) 1,750 kWt electric motor driven, water-cooled chillers (1) 1,140 kWt hot water-fired absorption chiller (2) 1,750 kWt electric motor driven, water-cooled chillers (1) 1,140 kWt hot water-fired absorption chiller
Boiler Plant (2) 1,750 kWt fire tube boilers producing hot water (2) 1,750 kWt fire tube boilers producing hot water
Thermal Storage (1) 10,000 kWt-hr chilled water storage tank connected to site chilled water distribution system (1) 10,000 kWt-hr chilled water storage tank connected to site chilled water distribution system
Power Generation (1) 2,000 kVA natural gas generator (cogeneration) (1) 2,000 kVA diesel generator (emergency power) (1) 2,000 kVA natural gas generator (cogeneration) (1) 2,000 kVA diesel generator (emergency power)
Diesel generators not required if onsite LNG
storage is provided
75
Summary of Options
Option Chiller Plant Boiler Plant Thermal Storage Power Generation
1 (4) 2,500 kWt electric (4) 2,750 kWt boilers None (2) 2,000 kVA diesel backup generators
1A (2) 2,650 kWt electric, (2) 2,450 kWt absorbers (4) 1,750 kWt boilers, (2) 1,500 kWt absorbers None (2) 2,000 kVA diesel backup generators
2 (4) 1,750 kWt electric (4) 2,750 kWt boilers (1) 30,000 kWt-hr chilled water storage (2) 2,000 kVA diesel backup generators
3 (4) 1,750 kWt electric, (2) 1,140 kWt absorbers (4) 1,750 kWt boilers None (2) 2,000 kVA natural gas cogen units, (2) 2,000 kVA diesel backup generators
4 (4) 1,750 kWt electric, (2) 1,140 kWt absorbers (4) 1,750 kWt boilers (1) 10,000 kWt-hr chilled water storage (2) 2,000 kVA natural gas cogen units, (2) 2,000 kVA diesel backup generators
76
Energy Model

• Simulation of plant operation
• Calculation of total energy use (power and fuel)
  and cost

77
Hourly Computer Model
78
Detailed Equipment Data
79
Monthly Energy Cost Summary
80
Monthly Energy Cost Graphs
81
Comparison of Annual Energy Costs
4.3 M
4.3 M
4.2 M
3.0 M
3.0 M
82
Thermal Storage Economics

• Installed Cost (Opt. 1A) 1,700,000
• Annual Energy Savings 98,000
• Simple Payback 17 years
• Low cooling load reduces benefits of thermal
  storage

83
25-Year Lifecycle Cost Analysis

• Capital Cost
• Energy Cost (gas and electric)
• Maintenance and Consumables Cost
• Staffing Cost
• Economic Rates
• Discount Rate

84
Construction Cost Estimates
85
Project Cost Factors

• Based on typical healthcare development projects
• Preliminaries and Margin 23
• Project Contingency 15
• Cost Escalation to Start Date 15
• Consultant Fees 10
• Total multiplier is approximately 1.8

86
Comparison of Initial Costs
87
Maintenance and Staffing Costs
Option Annual Maintenance Cost Annual Staffing Cost
1 84,000 130,000
1A 90,000 130,000
2 86,000 130,000
3 105,000 195,000
4 107,000 195,000

• Options 3 and 4 also require a 240,000 engine
  overhaul every 5 years (included in analysis)
• Staffing cost based on 65,000 per year for each
  full-time staff employee

88
Economic Parameters

• Based on estimated government rates
• Discount Rate 8.00
• Gas Cost Escalation Rate 4.30
• Electric Cost Escalation Rate 3.40
• Maintenance Escalation Rate 4.00
• Consumables Escalation Rate 4.00

89
25-Year Lifecycle Cost Analysis
90
Cost Summary
Option First Cost Annual Energy Cost 25-Year Present Worth Cost
1 20,839,000 4,345,000 87,223,000
1A 22,879,000 4,311,000 88,825,000
2 23,558,000 4,243,000 88,473,000
3 32,176,000 2,988,000 83,303,000
4 33,704,000 2,978,000 84,722,000
91
Results of Lifecycle Cost Analysis
92
Sensitivity Analysis

• Varying electric demand charge
• Varying gas cost
• Change economic parameters
• Carbon emission tax
• Use of geothermal energy

93

• Thank You
• Hemant Mehta, P.E.
• President
• WMGroup Engineers, P.C.
• [phone]
• hmehta_at_wmgroupeng.com