NGCP for upload

Presented By: Christine Lazo
Vertical Systems
7113 Telegraph Rd.
Montebello, CA 90640
310 451 0630
christine@vertisys.net

Presentation Overview
 Typical Problems of Chiller Plants
 Engineers Ability to Impact Change
 What is a Next Generation Central Plant?
 The BIG Secret!
 CPECS – The Difference is Controls
 Measuring Performance

Major Problem In Plants Today
INEFFICIENCY
Wasted Energy
Wasted Water
Difficult Maintenance
Hard to Service
Not Sustainable

Typical Problems of Chiller Plants
 Fixed Speed Keeps it Simple – and inefficient
 Poor Chiller compressor turndown 3:1 – old tech
IGV
 Systems that are governed by oil management
(can’t take cold cond water or low refrigerant flow)
 Fouled Heat Exchangers
 No Measurement of plant or chiller performance
 Mis-match for building requirements vs plant
capability - Too big or Too few compressors
 Plant Turndown Does not match Building AC
Required Turndown

4

Causes of problems in plants today
 Fouled Heat Exchangers

5

What we see when we survey plants…

6

The Dramatic Effects of Oil
• ASHRAE sampling shows average •Efficiency loss accounts for
percentages of oil present in substantial operation costs
chillers

7

What is Your Building’s

8

What ARI Standards told us then
and now…
% load ARI standard 1992 ARI standard 1998

100 17% 1%

75 39% 42%

50 33% 45%

25 11% 12%

• Newer studies prove that PART-LOAD is of greater importance than
previous studies indicated.
• Building spends 87% of time in the 25-75% of max load.
• ARI Standard 1998 is a NATIONAL rule of thumb based on assumptions
9

What is California Building
IPLV?
Weighted Average Values

% Load Reality
100 1%
75 12%
50 45%
25 42%

Any Bin Hour Analysis
Program
10

Building Load Depends on Region/Use
(Existing Trended Data)

LOTS of PART LOAD HOURS!
11

10 Story Office Building in Los Angeles
Energy Analysis conducted October 20th, 2009

*Analysis conducted on System Analyzer software
12

So-Cal Large Building Load Profile

13

Fixed Speed Everything –
FIRST COST PLANT =1.2 kw/ton

14

SMARDT/All Variable = .5 kw/ton or
better

15

What can we influence?

Ed Mazria – Architecture 2030
17

K Peterson - ASHRAE

18

K Peterson - ASHRAE

19

Influencers to change NOW
 Timing is great!
 New Technologies = Double efficiency
 Essentially FREE Equipment at some
sites!
 Usage component – up to 33 Cents
Rebate per an kwh saved
 Increases in power costs (Power = $$$)
 100% financing at low APRs for energy
efficient projects (2.9% for public jobs)

20

Improving the Central Plant Spec
 Learning by MEASURING
 Metric 1 = Wire to Water Efficiency Average
 Metric 2 = Water Efficiency (usage)
 Metric 3 = the MRS factor –maintainability,
reliability, sustainability

21

What does a Next Gen Plant NOT HAVE?
 Oil
 PID Plant Controls with fixed setpoints
 Chemical Treatment in Open Loop
 Sunlit Open Tower Basins
 Sand Filtration
 Base Mounted Pumps
 Across the Line and Y-Delta Starters
 Gears and Shaft Seals on Chillers

23

What Does Next Gen Plant NEED?
 Variable Primary Pumping
 Variable Condenser Pumping
 Variable Speed Oil-Free Magnetic Chiller
 Variable High Turndown Cooling Tower
 Measure Power of all Pumps, Chillers,
Towers
 Measure Delivered Chilled Water Flow
 Chemical Free Water Treatment
 Vertical Inline Pumps
 Centrifugal Separator Filtration 24

Components of the Next Gen Plant
 Smardt Oil Free Variable Speed Chiller
 CPECS All Variable Controls
 Ultra Quiet – Evapco UT Cooling Tower – Min. 50%
Turndown and Efficient.
 Pulse ~Pure - Chemical Free Water Treatment
 Armstrong Vertical Inline Pumping Packages
 Centrifugal Separator – Tower Filtration with solids
recovery- Zero water use.

25

What is the Aim of Next
Generation Central Plant Design?
 Reduce Water Consumption by
20%
 Reduce Energy Consumption by
Over 50%
 Reduce Maintenance by 50%
 Reduce Life Cycle Cost
 Reduce Size / Weight of the CP by
30%
 Reduce Health Impact / Liability
 Reduce Toxic Emissions
 Reduce Corrosion

27

THE

BIG Combining Turbocor
SECRET
and
All Variable Control

The Big Secret - Next Gen Plants
Combining Turbocor and All Variable Control

 Use Heat Exchangers designed to stay online
at part load AND lower ECWT

 CHANGE FROM - Capacity Based ON/OFF
control/individual PID loops
 CHANGE TO - Speed Based Demand Control
with low pressure loss valves

30

Take Advantage of Heat Exchangers
designed to stay online at part load

 Evapco Cooling Towers
Advances in tower nozzle design and chiller
condenser water circuit configurations allow
water flow through condenser to reduce all
the way down to 45% of nominal flow (10%
of full load pumping power).

Take Advantage of Heat Exchangers
designed to stay online at part load
AND lower ECWT
 Smardt Oil-Free Chillers
Turbocor Magnetic Bearing Compressors have
built-in VFD
Systems are not governed by oil management
○ can take cold cond water or low refrigerant flow

IPLV and Condensing Temperature
Ex: 400 Ton Smardt Water-Cooled Chiller

85°F ECWT

75°F ECWT

65°F ECWT
kW/Ton

% of Full Load

Fixed LCHWT = 44°F
Fixed Chilled Water and Condensing Water Flow Rate


85°F ECWT

75°F ECWT

65°F ECWT
kW/Ton

% of Full Load
Fixed LCHWT = 44°F
Fixed Chilled Water and Condensing Water Flow Rate


85°F ECWT

75°F ECWT

65°F ECWT
kW/Ton

55°F ECWT

% of Full Load
But Smardt WC Chillers can operate down to 55 °F
ECWT

What difference does it make?
 Chiller Efficiency is both a function of Load and “Lift of the Compressor”

 Lift relates to the condensing temperature which is determined by the
ECWT from the cooling tower or the EDBT from the condenser fans.

 When you reduce the condensing temperature, you reduce the work of
the compressor.

LESS WORK

LESS ENERGY
CONSUMPTION

The Impact of Load
kW/To
n

% of Full Load
For a Fixed ECWT, there is a 17% increase in efficiency between
100% load and 50% Load

Impact of Condensing Temperature
kW/Ton

0.280 kW/ton

0.180kW/ton

% of Full Load
At 50% Load
 36% LESS Energy Consumption

Considering 45% annual hours at 50% of Full Load (per AHRI 550/590)
 16.2% Annual Savings

Implement All Variable Control

40

Question:
What do you do to make an
All Variable Plant?

th
ANSWER:

My
Add VFDs to all the components. All plants
with VFD’s on them operate efficiently.

TRUTH:
Just installing drives on the equipment does not
guarantee energy savings!
A good example of this is putting a drive on a
cooling tower and applying a fixed set point.

Water Cooled Chiller Plants - Loops

Ambient Condenser Chilled Supply
Refrigerant
Air Water Water Air

Loops Driven By Pumps Through Heat Exchangers

HX Loops – A Closer Look

Conventional Chilled Water System
Constant Speed Operation

Loops Driven By Pumps through heat Exchangers

Current Control Solutions
PID LOOP

PID LOOP

CONSTANT
PID LOOP

Three PID Loops, behaving independently (silos).
Capacity based sequencing.
Complex “reset” for strategies for light load. 45

HX Loops - Managing Lift

Conventional Chilled Water System
Constant Speed Operation

HX Loops - Managing Lift

Typical Part Load Operation
Reduce Approach by Reducing Flow
Maximize HX Transfer Time

All Variable Speed Plants – The Difference is Controls

 A variable speed chiller that operates constant entering
condenser water temperature will perform only marginally
better than a much lower cost fixed speed chiller.
 Centrifugal chillers gain performance when the temperature
lift between the evaporator and condenser is reduced.

Effect of optimized
tower set point
control results in a
42% performance
difference on the
same Turbocor chiller

What does All Variable Do?
 All Variable Systems turn down with building demand by:

 Eliminating plant over pumping by controlling all pumps in
system
○ Chilled and condenser water pumps, compressors, and CT fans
○ Every RPM turned that is more than necessary is wasted energy!

 Using multiple compressors on single barrel to utilize surface
area
○ Offers better approaches and less work for compressors

 MEASURING WIRE TO WATER EFFICIENCIES (kW in/tons out)

All Variable Speed Plants

 Need advanced control algorithms combining
 chilled water pump,
 condenser water pump,
 tower fan and
 chiller speeds.

 What proven control system can do this
reliably, repeatedly, and cost effectively?

CPECS
Central Plant Energy Control System

All Variable Speed Plants CPECS
Central Plant Energy Control System

 CPECS combined with SMARDT oil free variable
speed chillers provides the following:
 Optimized tower water temperature control.
 Load matched variable speed condenser water pump
control that respects chillers minimum safe flow limits.
 Optimized chiller sequencing.
 Load based chilled water temperature reset
 Variable primary chilled water pump control.

 RESULT:
 Highest performance targets

CPECS All Variable Benefits
 Real time NIST Certified performance
 Optimizes entire plant/HX loops into
single system for lowest energy
consumption
 Packaged controls solution with Smardt
chiller for single source responsibility
 Energy trending
 Entire plant average 0.5kw/ton

52

Visual Performance

53

Measured Performance

54

Schematic of Hartman Loop

55

Topics to be covered

This presentation shall demonstrate the actual operating performance
difference between the CPECS optimized logic and two cases of
conventional logic:

a) Constant speed condenser water pumping and
towers attempting to achieve wet bulb plus 10F
(a widely documented means for optimal
control).

b) Constant speed condenser water pumping and
towers maintaining 78F water temperature.

Chillers used for test are 2x 250Ton WA092 SMARDT chillers fitted with 3x
TT300 R134a Turbocor compressors. Chiller location is Las Vegas. All data
taken from an actual operating plant and only VFD speed and temperature
set points have been altered.

CPECS Vs Conventional Logic (a)
Conventional control logic: CPECS control logic:
•Constant speed condenser water •CPECS VFD condenser water
pumps. pumps.
•Towers running to maintain Twb +10F •CPECS VFD tower fans.
•Plant kW/ton = 0.97 ~ 1.06kW/Ton •Plant kW/ton = 0.54 ~ 0.57kW/ton

CPECS Vs Conventional Logic (a)
• Total power input = 47.2kW • Total power input = 26.6kW

•Chiller performance improved by 8%.
• System performance decreased 70%
• Condenser water temperature after
25min running full speed fans only
decreased 2F.

Comparison (a) Conclusions

Despite the wet bulb temperature being 54F at the time
of test and the towers selected at 10F approach, a
theoretical condenser water temperature of 64F was not
reached within 25minutes. Instead many kW’s of non-
effective tower fan energy were used.

The net effect of the test showed that a 45% increase
in condenser water pump speed and tower logic that
chases the wet bulb temperature did not deliver an
increase in chiller performance anywhere close to being
able to offset the extra pumping and fan energy when
compared with CPECS.

Large
power
Comparison (a) data increase
seen due
to extra
pumping
and fan
energy
when
logic
changed.

CPECS Vs Conventional Logic (b)
•Constant speed condenser water •CPECS VFD condenser water
pumps. pumps.
•Towers running to maintain 78F •CPECS VFD tower fans.
temperature
•Plant kW/ton = 0.87 ~ 0.94kW/Ton •Plant kW/ton = 0.54 ~ 0.57kW/ton

CPECS Vs Conventional Logic (b)

• Total power input = 40.8kW • Total power input = 26.6kW
• Chiller performance decrease by 14%.
• System performance decreased 53%.

Comparison (b) Conclusions

Conventional plant design and control
logic decreases both chiller performance
and total plant performance at part load
when compared to fully optimized control
logic and VFD’S.

Comparison (b) data

Case (b) logic
applied
When
condenser water
temperature set
point increased
to 78F and
condenser water
pump forced to
60Hz both
pumping and
chiller energy
CPECS logic are increased.
operating here.

Time based on chart is 6 hours

Questions?
 Comments? Concerns?

Fixed Speed Everything –
FIRST COST PLANT =1.2 kw/ton

69

SMARDT/All Variable = .5 kw/ton or
better

70

Measured Performance

ITS ALL ABOUT PERFORMANCE!

71

Visual Performance

72

NGCP for upload

More Related Content

What's hot (20)

Similar to NGCP for upload (20)

Recently uploaded (20)

NGCP for upload

Editor's Notes