investigations of heat recovery in different refrigeration system solutions in supermarket
DESCRIPTION
Investigations of Heat Recovery in Different Refrigeration System Solutions in Supermarket. Samer Sawalha and Yang Chen Department of Energy Technology Kungliga Tekniska Högskola Stockholm-Sweden. Project summary. Analysis methods. Detailed outline. Parallel CO2 transcritical (TR1). - PowerPoint PPT PresentationTRANSCRIPT
Presentationsmaterial EFFSYS 2 dagen 2009-12-14
Investigations of Heat Recovery in Different Refrigeration System
Solutions in Supermarket
Samer Sawalha and Yang Chen
Department of Energy TechnologyKungliga Tekniska Högskola
Stockholm-Sweden
Project summary
Investigate whether CO2 is a good alternative solution for supermarket refrigeration-Combined
cooling and heating analysis
Investigate the heat recovery performance of the new system solutions –different heat
recovery options
System modifications and optimizations will take into account not only the cooling efficiency but also the efficient heat recovery according to the
needs in the supermarket
Presentationsmaterial EFFSYS 2 dagen 2009-12-14
Analysis methods
Field measurements
Computer simulation modelling
Experimental work-CO2 test rig
Presentationsmaterial EFFSYS 2 dagen 2009-12-14
Detailed outlineField Measurement (two supermarkets)-MSc thesis work of Jigme Nidup, presented on June
17, 2009-• CO2 parallel system solution with heat pump in cascade• CO2 booster system with de-superheating
Simulation models
• Refrigeration systems solutions• CO2 parallel• CO2 booster• R404A/CO2 cascade• NH3/CO2 cascade• R404A conventional with sub-cooling
• Heat recovery solutions• Fixed head pressure• Floating condensing-desuperheating• Cascade heat pump
Presentationsmaterial EFFSYS 2 dagen 2009-12-14
Parallel CO2 transcritical (TR1)
Oil cooler
Inter-CoolerOil cooler
- Pressure
-Temperature
KA1/KA2
FA1/FA2
18oC
-10oC-35oC
dTapp=5K
dTapp=5KdTapp=5K
dTsc=2K
dTsc=2K
dTsc=2K
Qoilcooler=15%
Qoilcooler=15%
dTsh=10KdTsh,ex=10K
dTsh,ex=15K
dTsh=10K
Presentationsmaterial EFFSYS 2 dagen 2009-12-14
Field measurement (TR2)
Oil cooler
Ground heat source
+ +
Floor heating
-Pressure
-Temperature
KAFA1/KAFA2
KA3
dTapp=5KdTapp=5K dTapp=5K dTapp=5KdTsc=2KdTsc=2K
Tevap -35oCdTsh=10K
dTsh=10K
dTsh=10K
Tevap -35
Tevap -10oC
dTsh,ex=15K
dTsh,ex=10K
Qoilcooler=15%
Qoilcooler=15%
Qoilcooler=15%
Presentationsmaterial EFFSYS 2 dagen 2009-12-14
NH3/CO2 Cascade
NH3
NH3/CO2 Cascade System
Total COP comparison
Presentationsmaterial EFFSYS 2 dagen 2009-12-14
-10 -5 0 5 10 15 20 25 30 35 400
0.5
1
1.5
2
2.5
3
3.5
4
4.5
COPtot_TR1 COPtot_CC1 Conventional R404A with SCNH3/CO2 Cascade
Outdoor temperature [°C]
CO
P_t
otal
-10 -5 0 5 10 15 20 25 30 35 400
0.5
1
1.5
2
2.5
3
3.5
COPtot_TR1 COPtot_CC1 Conventional R404A with SC NH3/CO2 Cascade
Outdoor temperature [°C]
CO
P_t
otal
Total COP comparison in HR mode
Presentationsmaterial EFFSYS 2 dagen 2009-12-14
-10 -5 0 5 10 15 20 25 30 35 400
1
2
3
4
5
6
COPtot_TR1 COPtot_CC1Conventional R404A with SC NH3/CO2 CascadeCOPtot_TR1 COP_f COPtot_CC1 COP_f
Outdoor temperature [°C]
CO
PMedium and low temp. COP
Presentationsmaterial EFFSYS 2 dagen 2009-12-14
Field measurement (TR2)
Oil cooler
Ground heat source
+ +
Floor heating
-Pressure
-Temperature
KAFA1/KAFA2
KA3
dTapp=5KdTapp=5K dTapp=5K dTapp=5KdTsc=2KdTsc=2K
Tevap -35oCdTsh=10K
dTsh=10K
dTsh=10K
Tevap -35
Tevap -10oC
dTsh,ex=15K
dTsh,ex=10K
Qoilcooler=15%
Qoilcooler=15%
Qoilcooler=15%
Presentationsmaterial EFFSYS 2 dagen 2009-12-14
-10 -5 0 5 10 15 20 25 30 35 400
0.5
1
1.5
2
2.5
3
3.5
4
4.5
0
5
10
15
20
25
30
35
COPtot_TR1 Conventional R404A with SCNH3/CO2 COP_f COPtot_TR2_totNH3/CO2 COP_f COPtot_TR1 COP_fCOPtot_conv COP_f TR2
Outdoor temperature [°C]
CO
P_t
otal
Total COP comparison-No condenser loop
Presentationsmaterial EFFSYS 2 dagen 2009-12-14
Ongoing and future tasks• Estimate the heating capacities in an average
size supermarket• Calculate the annual energy consumption of all
the solutions combinations in different climates• Conclude the best refrigeration-heat recovery
combinations for different climates• Experimental validation of CO2 systems in heat
recovery mode in laboratory environment
Presentationsmaterial EFFSYS 2 dagen 2009-12-14
Schematic of the CO2 test rig
Presentationsmaterial EFFSYS 2 dagen 2009-12-14
Experimental main task
• Overall system evaluation• Heat exchangers evaluation• Compressor losses and oil cooler capacity• System control
Presentationsmaterial EFFSYS 2 dagen 2009-12-14
Conclusions• Field measurements performed• Simulation models for several systems
built• Test rig built and running• CO2 systems have potential with:
-floating condensing and recovering heat from de-superheating
-connected to heat pump at the condenser loop
Presentationsmaterial EFFSYS 2 dagen 2009-12-14