Chuck Chen, Hansen, Case study on LC NH3 DX system in cold storage facility in Central China

2. Technical key points for
ammonia DX and a case study
in Central China
Hansen Technologies corporation

3. Background
- Traditional ammonia system is widely used
around the word
- High compliance cost
(limited in most places in China )
- Higher operation cost due to riser sizing especially
when pipe dimeter is oversized and riser is high
- Ammonia @ low temp is limited by technology
- New DX cooler and special Motorized valve for ADX

4. DX system Challenge
- Separation of liquid and vapor phases
-40℃ m³/kg -40℃ m³/kg V/V
R717 0.00145 1.554 1072
R22 0.00071 0.20584 290
R507 0.00077 0.13317 173
R404A 0.00078 0.14205 182
-30℃ m³/kg -30℃ m³/kg V/V
R717 0.00147 0.96453 656
R22 0.00072 0.1359 189
R507 0.00079 0.08866 112
R404A 0.0008 0.09459 118
-6℃ m³/kg -6℃ m³/kg V/V
R717 0.00155 0.35994 232
R22 0.00077 0.0572 74
R507 0.00085 0.3766 443
R404A 0.00085 0.04028 47
0℃ m³/kg 0℃ m³/kg V/V
R717 0.00156 0.2895 186
R22 0.00078 0.04715 60
R507 0.00086 0.03101 36
R404A 0.00087 0.0332 38

5. DX system Challenge
- Liquid expansion
valve sizing
a) Motorized valve is recommended
b) build-in strainer is recommended
c) Sizing MCV running at 80% capacity,
oversized can clause often ammonia
flood back
d) low mass flow due to very small
orifice diameter even 1.5mm, so 4mm
MCV can cover 80% ammonia
DX application

6. DX system Challenge
- Refrigerant distributor types

7. DX system Challenge
- Water in ammonia

8. DX system Challenge
- Minimum superheat control

9. Ammonia DX system advantages
- very low charge
a) Reduce coil charge by as
much as 30 to 50 times
compared to pumped
system
b) Reduce whole system charge
by 80% compared to pumped
system
c) Modular packages
0.15kg/KW to 0.77kg/KW

10. Ammonia DX system advantages
- Very efficient due to short defrost period

11. Ammonia DX system advantages
- Reliable
- Lower initial cost
- Lower jobsite installation period
SYSTEM IS SIMPLE

12. System configuration
1. Single stage single temp level

13. System configuration
2. Single stage multiple temp level

14. System configuration
3. Two stage multiple temp level

15. Case in Central China
- Cold storage in Hubei Province, contracted by Bingshan
- Multiple temp level
-42C@182KW/ -30C@507KW/ -15C@612KW/ -10@772KW
- 65 pcs electric expansion valve
- Superheat control
Conclusion
- Initial cost was reduced by about 5%
- Construction period was shortened by about 10%

16. Why ammonia DX is a good solution for China cold storage
industry"
- Simpler system, more reliable operation
- Lower initial cost
- More efficient
- Very low charge, low compliance cost
- Lowest job site installation, shorten construction period

17. Further in ammonia low charge in China

18. WHO WE ARE ?
WE ARE DOING AMMONIA CORRECTLY
AND MAKE IT GREAT AGAIN !!!