High Temperature Heat Pumps and Compressor Optimization€¦ · High temperature heat pumps and compressor optimization, Page 2 ... Air Water. Eric Winandy ... High temperature heat

High Temperature Heat Pumps and Compressor Optimization

Dr. Eric Winandy

Eric Winandy, Emerson Climate Technologies

High temperature heat pumps and compressor optimization, Page 2

Controls, 15%

Others, 2%

SHs, 19%Scrolls,

64%

Emerson Climate Technologies Europe: At-a-Glance

European Manufacturing Facilities

Sales €334 M

Employees 1,489

2011

Major HP Customers:



Heat Pump Standard Temperatures

Low Temperature

– 35°C

Medium Temperature

– 45°C

High Temperature

– 55°C

Very High Temperature

– 65°C

EN14511 (COP)

EN14825 (SCOP)

Scope of this

presentation



Major Challenges

High Temperature Heat Pump

High Temperature Lift

Efficiency: COP, SCOP

Heating capacity: at low ambient

Operating Map: High Discharge T°

Air

Water



Heat Pump Water Temperatures and COP

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

-25 -20 -15 -10 -5 0 5 10 15 20 25

H-C

OP

Outdoor Temp [ºC]

Optimised Two Stage60% Isoentropic Eff

30 ºC

40 ºC

50 ºC

60 ºC

70 ºC

80 ºC



“The trend towards two stage domestic heat pumps is essential if we want to improve from the present efficiency plateau of the marketed heat pumps”.

Prof Favrat, Zurich 2008



What is a two-stage Heat pump?

Booster

Cascade

Vapour Injection



2-Stage Compression - BOOSTERm + i

Condenser

Evaporatorm

HX

i

P

h

Efficiency, Heating capacity and op map: OK

But Complexity: 2 Compressors, Controls, Oil Management



P

h

Condenser

Evaporator m1

Evaporator 2nd

Condenser 1st

m2

High Stage

Low Stage

Refrigerant 2

Refrigerant 1

2-Stage Compression - CASCADE


But Complexity: 2 Compressors, Controls



m

HX

Vapour Injection

Scroll

Condenser

Evaporatorm

i+

i

P

h

2-Stage Compression- VAPOUR INJECTION


Simple : 1 Compressor, Controls, Oil Mgt

Same as single Stage Application



Summary Application and Compressor Technology

Heat Source Temperature

Wate

r Te

mp

era

ture

Flo

or

Rad

iato

r

Ground

Air

20.0

30.0

40.0

50.0

60.0

70.0

-30.0 -20.0 -10.0 0.0 10.0 20.0

Underfloor Heating

Radiator/DHW

Air/Water w/Radiator

What is next?Moduation-Variable Speed



Variable Speed ZHW**K1P

Compressor Component:

BPM Motor

Oil pump

EVI Component:

Shell Fitting

Dog Bone & O-rings

O-Ring



Fixed Speed Compressors SimulationAverage Climate (A)

0

2

4

6

8

10

12

14

16

18

20

-10 -5 0 5 10 15

kW

Outdoor Ambient Temperature ºC

Bivalent

Point

Back-up

Electrical

Heater

Need



0

2

4

6

8

10

12

14

16

-10 -5 0 5 10 15

kW

Outdoor Ambient Temperature ºC

Variable Speed CompressorAverage Climate (A)

Smaller Electrical Heater

Or

No Need At All

• Higher Compressor Efficiency

(Permanent Magnet Motor)

• Better Temperature Control

• Higher Comfort

• Reduced Compressor Cycling

Variable Speed



Simulated Systems CharacteristicsThree Different R410A Heat Pump Solutions

Defrost Included

– Same De-rating And Scheme For All Three Systems

Fan Power Consumption Considered

Water Pump And Other Aux Not Included

System # #1 – ZH12 #2 – ZHI11 #3 – ZHW16

Refrigerant R410A R410A R410A

Heating Optimised Yes Yes Yes

Enhanced Vapour Injection

(EVI) No Yes Yes

Motor Induction InductionPermanent

Magnets

Modulation Fixed Speed Fixed Speed Variable Speed



3.94.0

4.4

2.8

3.1

3.7

2.0

2.5

3.0

3.5

4.0

4.5

Fixed Speed Fixed Speed EVI Variable Speed EVI

SCO

P

SCOP Simulation ResultsComp W35 SCOP

Comp W55 SCOP

Seasonal Performance Calculation

EVI Effect

• Variable Speed Brings

Substantial SCOP

Increase To The System

• EVI (Enhanced Vapour

Injection) Effect Higher

At Higher Pressure

Ratio (Higher Water

Temperature)

• Variable Speed Scroll

Optimised For Higher

Pressure Ratio (Higher Water Temperature)

• High Water

Temperature Mandatory

For Retrofit Application

VS Effect



Conclusions

High Temperature Heat Pump Is A Challenging Technology

2 Stage Refrigeration Circuit Can Improve Substantially The COP And Heating Capacity At High Temperature Lift

Optimised Scroll Technology And Vapour Injection Allow High Temperature Operation While Increasing The Heat Pump SCOP. It Achieves A 2 Stage Within One Compressor

Variable Speed Technology Substantially Increases The

SCOP Of A/W Heat Pumps

Thank you for yourattention!Questions?

High Temperature Heat Pumps and Compressor Optimization€¦ · High temperature heat pumps and compressor optimization, Page 2 ... Air Water. Eric Winandy ... High temperature heat

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