GREE Photovoltaic DC Inverter Centrifugal Chillerashraeqatar.org/.../gree_pv_dc_inverter_centrifugal_chillers.pdf · GREE CAC Technical Seminar GREE Photovoltaic DC Inverter Centrifugal

GREE CAC Technical Seminar

GREE Photovoltaic DC

Inverter Centrifugal Chiller

Doha，Qatar

Feb.20th.2016

Petroleum and nature gas can be consumed for only 50 years

Coal can be consumed for only 100 years

By Y2020,copper,aluminium,tin and zinc will be mined completely .

The energy depletion and environmental pollution is indeed

threatening our life.

Air conditioner, especially the Central Air Conditioner takes over

60% of the energy consumption in the building.

How to find GREEN Energy Source for the Central Air

Conditioners becomes a big challenge for the HVAC industry.

GREE, as the world leading HVAC solution provider, we are the

first manufacturer to develop the high efficient DC Inverter

Centrifugal Chiller with Solar Power application.

Contents

1

GREE CVS Series Photovoltaic DC Inverter Centrifugal Chiller 3

GREE CVE Series DC Inverter Centrifugal Chiller2

GREE PV DC Inverter Centrifugal Chiller

GREE Milestones For Centrifugal Chiller

GREE Milestones For Centrifugal Chiller1

2005 2006

2008

2013

GREE Milestones For Centrifugal Chiller

The first China-

created Centrifugal

Chiller

IPLV=6.7

The first Magnetic

Turbocor Centrifugal

Chiller

IPLV=13

The first generation

Inverter Centrifugal

Chiller

IPLV=9.6

High Efficiency

DC Inverter

Centrifugal Chiller

IPLV=11.68

2014

GREE CVE DC Inverter Centrifugal Chiller2

★ Product Range

★ Product Innovative Features

★ Product Application Case Study

GREE CVE Series DC Inverter Centrifugal Chiller

★ Product Range

The capacity range of GREE DC Inverter Centrifugal Chiller is from 250Tons to 1500 Tons, which is the largest Inverter Centrifugal Chiller in the wolrd with DC Inverter Compressor Motor.

All-condition “wideband”

pneumatic design technology

High-speed direct-drive two-stage impeller

Air makeup and

enthalpy gain via

two-stage compression

★ Product Innovative features

“Low viscosity”

vaned diffuser

technology

High-speed PMS

varied-speed motor

Four-quadrant

airborne inverter





Air makeup and

enthalpy gain via


“Low viscosity”

vaned diffuser

technology

High-speed PMS

varied-speed motor

Four-quadrant

airborne inverter



Conventional single-stage compressor

Impeller

Growth Gear Motor

GREE CVE Series DC Inverter Centrifugal Chiller★ Product Innovative features


Conventional Single-Stage compressor

Impeller

Growth Gear Motor


High-speed Direct-drive Two-Stage Impeller

GREE DC Inverter Two-Stage Centrifugal Compressor

High-speed PMSM

Two-stage Impeller


High-speed Direct-drive Two-stage Impeller

GREE DC Inverter Two-Stage Centrifugal Compressor

High-speed PMSM

Two-stage Impeller


High-speed Direct-drive Two-stage Impeller

Growth Gear Motor

High-speed PMSM

Two-stage Impeller

DC Inverter Two-stage Centrifugal

Compressor

Comparison between single stage compressor and DC Inverter Two-stage

compressor

Single Stage Centrifugal Compressor

0 20 40 60 80 100 120 load

(%)

0

4

8

12

16

20

Mech

an

ical

loss (k

W)

DC Inverter

AC Inverter

Fixed Frequency

The compressor mechanical loss of 650RT unit is only 1~ 4 kW, dropped 10 kW compared

with the fixed-frequency unit. At the 25% load, the power of 650RT unit is about 60kW,

mechanical loss is reduced by 16.7%.

Less Mechanical Loss with DC Inverter Compressor

Comparison between single stage compressor and DC Inverter Two-stage

compressor

Noise Comparison of Compressors (650RT)

Lower Noise for the DC Inverter Compressor

The growth gear of DC Inverter Two-Stage Compressors is removed,without

high-frequency noise of the gear, the compressor noise is much lower, only

80dBA.

90dBA

80dBA

DC inverter Centrifugal

Compressor

Traditional Centrifugal Compressor

80dBA


Because of cancelling growth gear, the compressor overall size decreases, the volume

and weight of the DC inverter centrifugal compressor is only 40% of the same

capacity traditional compressor.

Dc Inverter Centrifugal Compressor

(650RT)

Traditional Centrifugal Compressor

(650RT)

L×W×H (mm): 2300×1100×1000

Weight (kg): 2980

L×W×H (mm): 1400×700×720

Weight (kg): 1200

Compact Design for DC Inverter Compressor





Air makeup and

enthalpy gain via


“Low viscosity”

vaned diffuser

technology

High-speed PMS varied-

speed motor

Four-quadrant airborne

inverter


Compressor operation

characteristic curve

Design target curve

Patent Technology

"Full Process" design method.

The optimization design of the impeller and

the diffuser can realize the high-efficiency

operation of the compressor under the load

range 25-100%. Compared with the

traditional method of full load operation, it

makes the efficiency loss of the compressor

much lower.

Refrigerant flow is simply controlled

through the varied speed of the compressor,

and the throttling loss can be reduced

largely in this way.

Qv

Pr 系系系系系系系

0. 8

0. 82

0. 84

0. 86

系系系

1. 0N

0. 86N

0. 75N0. 68N

1. 1N

系系系系系系系系

系系系系

Q

Pr

100%

2.6

1.6

2.4

2.0

1.8

1.4

1.2

75%50%25%

系系系系系系系

系系系系系系系系

系系

系系

1. 0N

系系系

系系系系

0. 8

0. 82

0. 84

0. 86

0. 86N

0. 75N0. 68N

stage efficiency

cycle

Surge line

Pressure

Ratio

Flow

AC operation

condition line

Variable speed stage

characteristic curve


All-condition “wideband” pneumatic design technology


/C̊

系系 ( %)

0 20 40 60 80 100

35

30

25

20

15

10

系系系系系

系 +系系系系系系系系

系系系系 +系系

+系系系系

GREE DC Inverter Centrifugal ChillerTraditional Inverter Centrifugal Chiller

Comparison of the capacity control logic

The traditional inverter centrifugal chiller realizes the capacity control by the

variable speed of the compressor and the variable opening angle of the guide vane

which begins under the load of 50~60%.

This DC inverter centrifugal chiller can realize this by directly changing the speed

of the compressor so that the throttling loss will be reduced greatly at the 25% load.

Load(%)

Co

olin

g w

ate

r inle

t tem

p.(°

C)


/C̊

系系 ( %)

0 20 40 60 80 100

35

30

25

20

15

10

系系系系系

系 +系系系系系系系系

系系系系 +系

系 +系系系系

Co

olin

g w

ate

r inle

t tem

p.(°

C)

Load(%)

Hot gas bypass+Impeller+speed adjustment

Guide blade

control +speed

adjustment

speed adjustment

Hot gas bypass+speed adjustment+Impeller

Guide blade

control+speed

adjustmentspeed adjustment


0.65 10

0.7

0.75

0.8

0.85

0.9

0% 25% 50% 75% 100%

20

30

40

50

60

70

80

90

100

110

Ad

iab

atic

Effic

ien

cy

Gu

ide

va

ne

op

en

ing

(%)

load

Insulation efficiency for wideband design

Typical AC insulation efficiency

Typical AC guide vane opening

Guide vane opening for wideband design

efficiency

curve

22%

Guide vane opening

Guide vane opening/efficiency curve

The efficiency under Full process can reach more than 0.83. Compared with conventional

compressor, the efficiency increases 22% at 25% load.





Air makeup and

enthalpy gain via


“Low viscosity”

vaned diffuser

technology

High-speed PMS

varied-speed motor

Four-quadrant

airborne inverter


Unique “Low viscosity” vaned diffuser design and Airfoil guide vane, effictively

making high-speed gas convert into high static pressure gas and realize pressure

recovery with high efficiency.

In partial load, the vane diversion effectively reduces backflow loss, improves the

performance in partial load, and expands the scope of the unit operation. The unit

performance of partial load can be promoted more than 8%.

Airfoil guide vane

Patented

Technology


"Low viscosity” vaned diffuser technology

High-speed PMS

varied-speed motor




Air makeup and

enthalpy gain via


“Low viscosity”

vaned diffuser

technology

Four-quadrant

airborne inverter


The First 400kW Motor

Rotating Speed 12000rpm

Rotor

First high power and high-speed permanent magnet synchronous frequency control motor

of refrigeration centrifugal compressor.

The power of motor is more than 400 kW , and the rotate speed is more than12000 rpm.

The rotor structure design:

When the rotor is too big, the permanent

magnets will be damaged easily; when the

rotor is too small, the output will be

insufficient .

Magnetic circuit designed for both high and

low speed.

Eliminate resonance and harmonic.

High-speed bearing design.


High-speed PMS varied-speed motor

Motor with high efficiency

PMS motor, with the

permanent magnetic rotor

and no excitation loss;

Maximum torque/minimal

current rector control, with

less tear and wear to the

motor;

Optimized air-gap magnetic

field waveform, with less

harmonic loss.0.92

0.94

0.96

0.98

2000 4000 6000 8000 10000

effic

ien

cy

rotate

speed

12000

Unit operation scope

Within the scope of unit operation, the motor efficiency were above 96%, the highest

efficiency is 97.5%, more than national motor GRADE ONE energy saving level. The

efficiency is promoted up to 4%.


High-speed PMS varied-speed motor

Four-quadrant

airborne inverter

High-speed PMS

varied-speed motor




Air makeup and

enthalpy gain via


“Low viscosity”

vaned diffuser

technology


Conventional inverter technology

Options: installation harmonic filter

Input rectifier Inverter

DC bus

Linear control or capacitor

reduce harmonic content.

Diode conversion

AC into the DC.

Capacitor make the current

level off and storage, then

send it to the inverter.

Transistor, accurate control the

power that send to the motor.

Ac circuit motor


Four-quadrant airborne inverter

GREE DC Inverter Technology

Four-quadrant green inverter，IGBT Transistor instead of the traditional diode rectifier to

better control time and way of the power output , and fully suppress the harmonic.

DC bus

AC Circuit Motor

Active front end

(AFE) rectifierInverter



Low THD value (Total harmonic distortion)

Current waveform of traditional Inverter

CVE centrifugal chiller use the PWM controlled rectifying technology, total harmonic

distortion rate THD < 5%;

No auxiliary circuit reactance and harmonic isolation implement, reduce the cost of users;

Especially suitable for scientific research institutions, hospitals, factories &

schools ,which need low harmonic interference.

Current waveform of GREE DC Inverter



Current waveform of GREE DC Inverter

0%

10%

20%

30%

40%

THD comparison

GREE CVE

Traditional inverter

CVE centrifugal chiller use the PWM controlled rectifying technology, total harmonic

distortion rate THD < 5%;

No auxiliary circuit reactance and harmonic isolation implement, reduce the cost of users;

Especially suitable for scientific research institutions, hospitals, factories & schools, which

need low harmonic interference.

Low THD value (Total harmonic distortion)



Air makeup and

enthalpy gain via


Four-quadrant

airborne inverterHigh-speed PMS

varied-speed motor




“Low viscosity”

vaned diffuser

technology


Leading technology

Evaporation

Condensing

Throttlingcompression

Save power

Refrigerating capacity increase

The P-h figure of cycle

single-stage compression

Two-stage compression

Compared with the single-stage refrigeration system, the two-stage compression fill gas

circulation is the best choice, and it can improve the circulation efficiency 5 ~ 6%.

The two-stage compression, circulation system of high efficiency; Compared with

single stage compression, the rotating speed is lower, and the reliability is higher.


Air makeup and enthalpy gain via two-stage compression

Project Cases Study

• Project area: 100000m2

• Required Cooling load: 1600 kW

• Type:DC Inverter Centrifugal Chiller

• Annual runtime: 2500h

DC Inverter

Centrifugal

Chiller

Fixed frequency

Centrifugal Chiller

Refrigerating capacity

(kW)2285 2285

COP 11.2 6.7

Performance

improvements67%

Running time (h) 2500 2500

Power consumption

(kw·h)3570313 5968284

Power saved (kw·h) / 2397971

Saving ratio / 40%

Cost saved (RMB) 2637768

Coal saved (Ton) 969

Reduction of CO2

emissions (Ton)2391

Note: 1 KWh =1.1 yuan= 0.404kg coal= 0.997kg CO2 emission.

Payback period for New project :

= 7 x 0.2million / 2.63million

= 0.53 years

Payback period for

Replacement project = 7 x 1

million / 2.63 million

= 2.6 years

★ Product Application Case Study

GREE CVS Series Photovoltaic DC Inverter Centrifugal Chiller 3

★ System Composition--3 Systems

★ Product Innovative Technologies

★ System Operating Modes

★ Typical Project Application


System 1: HVAC System

System-2:Photovoltaic System



System-2:Intelligent Management System

5 Core

Technologies

PV

Direct-driven

Technology

MPPT

Technology

PAWM

Technology

Power

Integrated

Management

Technology

Ternary

Commutation

Technology


PV direct-driven tech

Public power

supplyCurrent converter

DC busbar

Traditional Solution 1Traditional Solution 2Gree Unique Solution

Utilization of PV power: 99%

Energy efficiency: 6%～8%Interconnected inverter

Centrifugal Chiller

Solar cell array

Confluence

unit


GREE PV Direct-driven Inverter Chiller

DC

Traditional ACPV sub-assy PV inverter

Traditional PV AC Application

Total equipment cost is reduced by 10%,Lower wastage & larger power generation.

PV sub-assy PV direct-driven inverter centrifugal chiller

DC

AC

Save equipmentSave transition

System Advantage


PV power can be best utilized, up to 99%

System can cancel the stabilizing unit.

StabilizingUnit

Confluence

unit

With Maximum Power Point Tracking Tech:

PV power will be utilized prevail.


With Pulse Amplitude-Width Modulation interleaving control tech:

Respond quick change of PV voltage and dynamic requirement of compressor

load in real-time .

Realize the self-adaptation control of compressor .

Assure stable and reliable operation of system.


Intelligent management for power.

Analysis the relationship between AC load and solar irradiance, adjust operation

control strategy automatically.

Improving the utilization ration of PV power.


PVSub-assy

Confluence &

Distribution

PV System

Load

Current converter

Ternary current inversion among: PV system, Centrifugal chiller & Power line.

Power line

It takes less than 10ms to switch to any of the 5 working modes.


5Operating

modes

Pure

AC mode

Pure

PV mode

PV

AC mode

PV AC &

Power

generation

mode

PV AC &

Power

consumption

mode


Confluence

unit

When PV generation is not available, Chiller will be powered by

commercial power.

Current converter


When the Chiller is turned off

Confluence

unit

Current converter


Confluence

unit

Current converter

When PV power generation is equal to AC power consumption:


Confluence

unit

Current converter

When PV power generation is more than AC power

consumption:


Confluence

unit

Current converter

When PV power generation is less than AC power

consumption:


Total Area 8000 m2

Type of PV plate Multicrystal silicon

Total capacity 803kWp

System name(System 1)

PV power generation

System for lighting

(System 2)

PV Direct-driven

Inverter Centrifugal

Chiller

Project area 4110m2 3890m2

No. of PV plate 1650 pieces 1562 pieces

System capacity 412.5kWp 390.5kWp


Power Generation 831600 kWh per year.

Free Electricity, save 140000 USD per year.


Save fuel

216200 (L)

Save coal

299.38 (ton)


Enjoy GREEN Life with GREE AC

Documents

GREE Photovoltaic DC Inverter Centrifugal Chillerashraeqatar.org/.../gree_pv_dc_inverter_centrifugal_chillers.pdf · GREE CAC Technical Seminar GREE Photovoltaic DC Inverter Centrifugal