HFO Facts
References
LIST OF INPUTS/ASSUMPTIONS – Eco-Efficiency Calculations (Retail)
Honeywell calculations. Full set of assumptions below.
INPUTS/ASSUMPTIONS
1. Complete replacement of current installed stores to HFO based solution (R445A or 471A) or CO2 or propane
2. Calculation is based on Frankfurt climate conditions. For warmer locations in the EU, the increase of CO2 emissions and cost would be higher. Reference: BinMaker Pro
BinMaker® Pro v 4.0 https://sales.gastechnology.org/100013.html, accessed on: 03/03/2023
3. Compressor technology piston reciprocating (model details given below)
4. EU Average energy cost, 0.15 - 0.49 €/kWhr: https://www.statista.com/statistics/1267500/eu-monthly-wholesale-electricity-price-country/
5. Average Equipment lifetime, 10 yrs
6. Chiller required in R290 secondary loop; COP of 6; % of operation annually, 60%
7. Cooling load distribution:
i. 95% of the installed refrigeration load is utilized for 15 hours (out of 24) when store is trading
ii. 70% of the installed refrigeration load is utilized for 9 hours (out of 24) when store is not trading
8. Evaporating temperature fixed -8oC for MT fixed -32oC for LT
9. Condensing temperature
System |
MT range |
LT range |
R-744 |
Ambient +5 K but not lower than 10 oC, for transcritical operation gas cooler exit temperature is 3K above ambient |
Fixed -8 oC |
R-290 |
Fixed 28oC since plug in cabinets are located inside a store with ~constant temperature |
Fixed 28oC since plug in cabinets are located inside a store with ~constant temperature |
R-455A and R-471A |
Ambient +5 K but not lower than 15 oC |
Ambient +5 K but not lower than 15 oC |
10. Temperature difference for cascade (R455A/R471A) and secondary heat exchanger (R290), 5K
11. Leak Rates
Refrigerant |
Leak rate |
R-744 |
20% since it is a high-pressure fluid |
R-290 |
2% since it works in hermetic system in plug in cabinets |
R-455A |
10% average leak rate in EU for R-404A like fluids in centralized/semi centralized systems |
R-471A |
5% since it is a low-pressure fluid |
12. Estimated average charge sizes each type of store
|
Supermarket |
Hypermarket |
Small Supermarket |
Convenience Store |
Charge, kg |
300 |
1200 |
60 |
30 |
Avg Store Size, m2 |
1000 |
6500 |
500 |
200 |
13. Estimate Medium Temperature (MT) and Low Temperature (LT) capacities for different stores sizes
store size |
Charge |
# of stores |
MT cap |
LT cap |
(sqm) |
(kg) |
(-) |
(kW) |
(kW) |
200 |
30 |
126,425 |
10 |
2 |
500 |
60 |
46382 |
24 |
5 |
1000 |
300 |
37111 |
130 |
25 |
6500 |
1200 |
7975 |
420 |
80 |
14. Refrigerant Used
Store Type |
HFO based Solution |
Non-HFO Solution |
||
|
LT |
MT |
MT |
LT |
Supermarket |
455A |
471A |
CO2 |
|
Hypermarket |
455A |
471A |
CO2 |
|
Small Supermarket |
455A |
Propane |
||
Convenience Store |
455A |
Propane |
||
15. CO2 system; optimal high side pressure – Sawalha (2008); energy improvement for parallel compressor plus ejector cycle, 10%
Sawalha, S., 2008. Theoretical evaluation of trans-critical CO2 systems in supermarket refrigeration. Part I: Modeling, simulation and optimization of two system solutions. international journal of refrigeration, 31(3), pp.516-524.
16. Compressor Curves
C-store, small supermarket |
||||||||||
R-290 MT, LT |
||||||||||
C0 |
C1 |
C2 |
C3 |
C4 |
C5 |
C6 |
C7 |
C8 |
C9 |
|
Q (W) |
3830.431 |
135.7552 |
-11.5907 |
1.608565 |
-0.67242 |
-0.6217 |
0.007699 |
-0.00596 |
-0.00378 |
0.004312 |
P (W) |
450.831 |
-4.4169 |
1.159554 |
-0.179 |
-0.03595 |
0.193776 |
0.002794 |
0.004547 |
0.006708 |
-0.00125 |
m (kg/h) |
33.03167 |
1.063232 |
0.170961 |
0.01102 |
0.002233 |
-0.00682 |
5.59E-05 |
2.57E-05 |
-3.7E-05 |
3.91E-05 |
R-455A MT |
||||||||||
C0 |
C1 |
C2 |
C3 |
C4 |
C5 |
C6 |
C7 |
C8 |
C9 |
|
Q (W) |
46494.4 |
1666.283 |
-463.402 |
21.40508 |
-13.111 |
-0.60432 |
0.10361 |
-0.10012 |
0.001673 |
0.010188 |
P (W) |
1708.66 |
-136.749 |
193.9651 |
-3.97984 |
6.007311 |
-1.00466 |
-0.02825 |
0.042991 |
-0.0159 |
-0.00064 |
m (kg/h) |
777.5583 |
26.17091 |
-2.39618 |
0.322762 |
-0.03932 |
-0.02346 |
0.00166 |
2.42E-05 |
-0.00015 |
8.77E-05 |
R-455A LT |
||||||||||
C0 |
C1 |
C2 |
C3 |
C4 |
C5 |
C6 |
C7 |
C8 |
C9 |
|
Q (W) |
46118.8 |
1653.827 |
-462.842 |
21.25007 |
-13.1147 |
-0.59807 |
0.102769 |
-0.10043 |
0.001568 |
0.010136 |
P (W) |
1713.917 |
-136.435 |
193.7564 |
-3.976 |
6.005689 |
-1.00476 |
-0.02824 |
0.043008 |
-0.01592 |
-0.00065 |
m (kg/h) |
776.4534 |
26.13952 |
-2.39591 |
0.322397 |
-0.03935 |
-0.02349 |
0.001658 |
2.37E-05 |
-0.00015 |
8.77E-05 |
Supermarket, hypermarket |
||||||||||
R-744 MT |
||||||||||
C0 |
C1 |
C2 |
C3 |
C4 |
C5 |
C6 |
C7 |
C8 |
C9 |
|
Q (W) |
41041.31 |
1391.413 |
-839.155 |
19.17435 |
-11.468 |
20.90983 |
-0.04154 |
-0.39029 |
-0.37074 |
-0.55557 |
P (W) |
1524.987 |
-112.27 |
123.7113 |
-1.69211 |
-0.15058 |
1.521209 |
0.003621 |
-0.03429 |
0.061404 |
-0.01464 |
m (kg/h) |
585.6053 |
21.0829 |
-3.04977 |
0.337399 |
-0.08417 |
-0.00156 |
0.003276 |
-0.00116 |
-0.00012 |
-8.2E-05 |
R-744 LT |
||||||||||
C0 |
C1 |
C2 |
C3 |
C4 |
C5 |
C6 |
C7 |
C8 |
C9 |
|
Q (W) |
7707.002 |
250.846 |
-110.606 |
2.474551 |
-2.34275 |
-0.40303 |
0.004338 |
-0.00705 |
-0.01794 |
0.008425 |
P (W) |
182.0296 |
-41.9046 |
41.51396 |
-0.94743 |
1.182989 |
-0.1921 |
-0.00552 |
0.0098 |
-0.00442 |
0.000586 |
m (kg/h) |
111.4106 |
3.641336 |
-0.52384 |
0.036707 |
-7.3E-05 |
-0.00886 |
7.24E-05 |
0.000191 |
-0.00031 |
0.000141 |
R-471A MT (proxy by R-1234ze compressor) |
||||||||||
C0 |
C1 |
C2 |
C3 |
C4 |
C5 |
C6 |
C7 |
C8 |
C9 |
|
Q (W) |
179484.6 |
6800.371 |
-1963.63 |
105.8457 |
-45.2238 |
19.73852 |
0.663551 |
-0.62708 |
-0.03464 |
-0.21983 |
P (W) |
2630.159 |
81.5654 |
1103.599 |
12.61078 |
2.778549 |
-17.0484 |
-0.09029 |
-0.2241 |
0.020984 |
0.176253 |
m (kg/h) |
3095.229 |
90.64566 |
2.232313 |
0.930813 |
1.024726 |
0.095434 |
0.006572 |
0.013108 |
-0.01089 |
-0.00349 |
R-455A LT |
||||||||||
C0 |
C1 |
C2 |
C3 |
C4 |
C5 |
C6 |
C7 |
C8 |
C9 |
|
Q (W) |
46118.8 |
1653.827 |
-462.842 |
21.25007 |
-13.1147 |
-0.59807 |
0.102769 |
-0.10043 |
0.001568 |
0.010136 |
P (W) |
1713.917 |
-136.435 |
193.7564 |
-3.976 |
6.005689 |
-1.00476 |
-0.02824 |
0.043008 |
-0.01592 |
-0.00065 |
m (kg/h) |
776.4534 |
26.13952 |
-2.39591 |
0.322397 |
-0.03935 |
-0.02349 |
0.001658 |
2.37E-05 |
-0.00015 |
8.77E-05 |
17. Factor of 1.1 is used across all refrigerants to correct the offset of compressor suction temperature (coefficients vs actual suction)
18. GWP values of AR4 are adopted
19. Average Carbon intensity of electricity for entire EU = 0.43 kg CO2/ kWh
20. Carbon Intensity for individual Countries: https://app.electricitymaps.com/zone/DE?utm_source=linkedin&utm_medium=social&utm_campaign=israelandsa
Country |
Carbon Intensity over past 12 months |
|
kg CO2eq / KWh* |
France |
0.103 |
Germany |
0.504 |
Spain |
0.185 |
Italy |
0.4 |
Czechia |
0.536 |
Poland |
0.768 |
Additional Comments
1. R290 plug-in cabinets heat dissipation into the store (compressor) not included which in real store must be compensated by air conditioning.
2. If defrost is considered it’s an additional energy consumption.
3. For R744, leak rate of 20% is very conservative, more realistic values in warm ambient are close to 40%.
References- Key Benefits of HFO Solutions
1. Based on thermodynamic analysis with following conditions: Evaporation Temperature of 20F for R404A, R471A and CO2 (2) Evaporator Superheat of 9F for R404A, R471A and CO2 (3) Suction Superheat of 18F for R404A, R471A and CO2 (4) Compressor Isentropic Efficiency of 65% and Volumetric as 100% for R404A, R471A and CO2 (5) Ambient Temperature of 85F; Condensing Temperature for R404A and R471A is 105F (20F TD; 0F Subcooling) and for CO2 Gas Cooler Outlet Temperature is 89F (4F Approach Temperature) (6) Gas Cooler Pressure for CO2 is 83 bar which is 1204 psia (7) Capacities R404A, R471A and CO2 are matched
2. https://www.fluorocarbons.org/applications/insulation-foam-blowing-agent
3. https://energy.ec.europa.eu/topics/energy-efficiency/heating-and-cooling_en