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High Ambient Energy Efficient CO2 Refrigeration Unit for Supermarket and CVS.

Oct. 11th 2011 SANYO Electric Co., Ltd.

Commercial Solutions Company Gaku Shimada

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Agenda

1. Introduction of LAWSON Activity (Japanese CVS chain)

2. Refrigerant Transition in Japan for Commercial refrigerator (SANYO’s view)

3. Efficiency Analysis (CO2 and R404A)

- Labo test at Rated Test Condition

- Measured data from the field (Winter ~ Summer)

- Theoretically calculated efficiency

4. Consideration and Summary

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Introduction of LAWSON’s Endeavor to convert to Natural Refrigerant

Total 50 demonstration stores covering all 7 branches will open before March 2012.

Verify the energy consumption difference by location and climate. Spread out 500 stores by 2016.

Kanto

Tohoku

Hokkaido

Chubu

Kinki

Kyusyu

Chugoku Shikoku

1st Model Store opened at Kyo-tanabe since Dec. 2010.

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Demonstration Store to verify the CO2 units (Y2015 Candidate)

Outdoor units for Refrigerators and Freezers were replaced by SANYO CO2 Units (10HP and 2HP)

The Total Energy Save: 32%

CO2冷凍機 2HP

Walk –in Show CasesOpen Show Cases

Glass Door Freezer

Dessert Cases

R404A Ice Case

R410A PAC

R404A Com. Ref.

R404A Drink Case

2 HP CO2 Outdoor Unit

10 HP CO2 Outdoor Unit

Can be replaced by

CO2 unit eventually

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Agenda

1. Introduction of LAWSON Activity (Japanese CVS chain)

2. Refrigerant Transition in Japan for Commercial refrigerator (SANYO’s view)

3. Efficiency Analysis (CO2 and R404A)

- Labo test at Rated Test Condition

- Measured data from the field (Winter ~ Summer)

- Theoretically calculated efficiency

4. Consideration and Summary

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Refrigerant Transition in Japan (SANYO’s view)

Ｒ22

Ｒ410Ａ

Ｒ404Ａ

ＣＯ２

2007 2008 2010 2006 2009 2011 2012

ＧＷＰ：1,900

ＧＷＰ：3,300

ＧＷＰ：1,750 ＧＷＰ：1

Considering the Environment Impact, CO2 is the best refrigerant for Commercial Refrigeration System.

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Transition of COP at Rated Condition (AT 32C)

◆ Freezer (- 40C Eva. Temp.) AT: 32C Year 2000 2008 2010 2011

Model Code OCU-S2002DF OCU-NS2000MVF OCU-

GS2000MVF Sales started in 2010

Motor Type Single Speed Single Speed INVERTER INVERTER

Refrigerant R22 R404A R404A R744

Cooling Capacity (kW)

11.0 12.4 12.4 14.3

Input (kW) 12.7 14.9 14.9 14.2

COP 0.87 0.83 0.83 1.01

Year 2000 2008 2010 2011

Model Code OCU-S2002DF OCU-NS2000MVF OCU-GS2000MVF To be determined

Motor Type Single Speed Single Speed INVERTER INVERTER

Refrigerant R22 R404A R404A R744

Cooling Capacity (kW)

37.3 42.6 42.6 32.5

Input (kW) 17.3 21.4 21.3 16.3

COP 2.16 1.99 2.00 1.99

◆ Refrigerator (- 10C Eva. Temp.) AT: 32C

At Rated Condition Comparison, there is no big COP improvement.

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Measured Energy Consumption Comparison

◆ Freezer Application Room temp: -25C

◆ Refrigerator Application Room temp: +5C

20

40

60

80

100

120

140

160

180

0 10 20 30 40外気温 〔℃〕

消費

電力

量 〔kWh/day〕

CO 2冷凍機

R404A冷凍機

0

20

40

60

80

100

120

140

160

180

0 10 20 30 40

外気温〔℃〕

R404A冷凍機

CO 2冷凍機消費電力量　〔kWh/day〕

Energ

y

Consum

ption

Ambient Temp.

(24h averaged) Ambient Temp.

(24h averaged)

Energ

y

Co

nsu

mp

tio

n

R404A

CO2

R404A

CO2

Though we don’t see big difference at rated condition comparison, CO2 is confirmed to outperform R404A system at Measured Energy Consumption Comparison. Why ??

CO2 is better than

R404A by 16 ~ 26%.

Cross Point at 38~40C AT.

CO2 is better than

R404A by 0 ~ 30%.

Cross Point at 32C AT.

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Why CO2 unit works better than expected?

CO2 refrigerant is said to be less efficient. But the actual data is different. Why ??

Though we don’t see big difference at rated condition comparison, CO2 is confirmed to outperform R404A system at Measured Energy Consumption Comparison. Why ??

1. CO2 performs relatively better at cold climate.

AT 32C comparison may not be fair.

2. Components are different (HX, DC INV motor, etc..).

3. Refrigeration Cycle is different.

Good cycle for R404A is not best for CO2.

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Definition of Theoretical Efficiency

◆ Temperature Trend at “Gas Cooler Inlet ~ Outlet”

20

30

40

50

60

70

300 350 400 450 500

比エンタルピー　〔kJ/kg〕

温度

〔℃

〕 R 404A (≒実際） 〔凝縮42℃, 出口37℃〕

CO 2計算：出口温度同一条件

CO 2計算：伝熱性能同一条件

CO 2実際

入口

出口

Enthalpy

CO

2 T

em

pera

ture

GC Inlet

GC Outlet

GC Inlet GC Outlet

Actual CO2 Temp.

Calculated CO2 temp based on same outlet temp.

Calculated CO2 temp based on same Heat

Transfer Coefficient during GC flow.

R404A (≒ Actual)

CT: 42C, Outlet: 37C

Calculated CO2 temperature trend based on same Heat Transfer Coefficient matches the actual temperature trend.

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Definition of Cycle

◆ Refrigeration Cycle Compared in this study

CO2 Split Cycle CO2 Conventional Cycle R404A Conventional Cycle

Compression Two-stage (utilize Intercooler) One-stage

SLHX Yes No

Split

(Economizer) Yes No

PH Diagram

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0

0.5

1

1.5

2

2.5

3

3.5

4

5 15 25 35

外気温〔℃〕

COP

CO 2ｽﾌ ﾘ゚ｯﾄｻ ｲｸﾙ

(2段圧縮)

CO 2通常ｻｲｸﾙ(2段圧縮)

R 404A通常ｻｲｸﾙ

Theoretically Calculated Efficiency Comparison

Using the same Heat Transfer Coefficient, the system COP of CO2 split cycle can outperform R404A. same trend as measured data.

◆ Freezer Application - 40C Eva. Temp.

◆ Refrigerator Application - 10C Eva. Temp.

Ambient Temp.

1

2

3

4

5

6

7

8

9

10

11

5 15 25 35

外気温 〔℃〕

COP

CO 2ｽﾌ ﾘ゚ｯﾄｻ ｲｸﾙ(2段圧縮)

CO 2通常ｻｲｸﾙ(2段圧縮)

R 404A通常ｻｲｸﾙ

CO2 Split Cycle

2-stage

CO2 Conventional

2-stage

R404A Conventional

CO2 Split Cycle

2-stage

CO2 Conventional

2-stage

R404A Conventional

CO2 is better than

R404A by 3 ~ 7%. CO2 efficiency is

almost same as R404A

Ambient Temp.

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Consideration and Summary

1. The superiority of CO2 cycle efficiency is difficult to be confirmed at rated condition (AT32) comparison. But, actually CO2 outperforms R404A in the market.

2. The measured data comparison showed that CO2 split cycle is better than R404A original system by 16-26% at LT use and 0-30% at MT use. Cross point exists at high ambient temp. more than 32C.

3. Theoretically calculated efficiency based on the same Heat Transfer Coefficient showed that CO2 split cycle is better than R404A original system by 3-7% at LT use and almost same at MT use.

4. The remaining GAP of efficiency comparison (measured v.s. calculated) might be resulted from the components improvement.

It is fair. New technology shall be used for new refrigerant. It is natural to pursue the best performance with available technology.

Next steps?