What are requirements for the coolant used in a hydro-cooling system.

You can refer to the following content for details

If a liquid medium uses pure water + special corrosion inhibitor + antifreeze, parameters related to the liquid temperature and the liquid flow of ethylene glycol or propylene glycol solution + pure water (distilled water) + special corrosion inhibitor are shown in Table 1‑1.

Table 1‑1

Item

Coolant

Liquid temperature

Liquid flow

20 % ethylene glycol or propylene glycol solution + pure water (distilled water) + special corrosion inhibitor

Working temperature (inlet): 20 ℃ – 50 ℃ @ normal mode, 20 ℃ – 39 ℃ @ high performance mode

Inlet liquid temperature control accuracy: ± 2 ℃

Storage and transportation temperature: -40 °C – +70 ℃

Note: The liquid in the hydro-cooling miner must be emptied after storage and transportation for more than 2 hours.

Rated flow: ≥ 10.7 L/min

Flow control accuracy: ± 10 %

Note: Temperature difference between inlet liquid and outlet liquid corresponds to 10.7 L/min is close to 10 ℃ @ normal mode, and 14 ℃ @ high performance mode.

30 % ethylene glycol or propylene glycol solution + pure water (distilled water) + special corrosion inhibitor

Working temperature (inlet): 20 ℃ – 49 ℃ @ normal mode, 20 ℃ – 38.5 ℃ @ high performance mode

Inlet liquid temperature control accuracy: ± 2 ℃

Storage and transportation temperature: -40 °C – +70 ℃

Note: The liquid in the hydro-cooling miner must be emptied after storage and transportation for more than 2 hours.

Rated flow: ≥ 11 L/min

Flow control accuracy: ± 10 %

Note: Temperature difference between inlet liquid and outlet liquid corresponds to 11 L/min is close to 10 ℃ @ normal mode, and 14 ℃ @ high performance mode.

40 % ethylene glycol or propylene glycol solution + pure water (distilled water) + special corrosion inhibitor

Working temperature (inlet): 20 ℃ – 48 ℃ @ normal mode, 20 ℃ – 38 ℃ @ high performance mode

Inlet liquid temperature control accuracy: ± 2 ℃

Storage and transportation temperature: -40 °C – +70 ℃

Note: The liquid in the hydro-cooling miner must be emptied after storage and transportation for more than 2 hours.

Rated flow: ≥ 11.4 L/min

Flow control accuracy: ± 10 %

Note: Temperature difference between inlet liquid and outlet liquid corresponds to 11.4 L/min is close to 10 ℃ @ normal mode, and 14 ℃ @ high performance mode.

50 % ethylene glycol or propylene glycol solution + pure water (distilled water) + special corrosion inhibitor

Working temperature (inlet): 20 ℃ – 47 ℃ @ normal mode, 20 ℃ – 37.5 ℃ @ high performance mode

Inlet liquid temperature control accuracy: ± 2 ℃

Storage and transportation temperature: -40 °C – +70 ℃

Note: The liquid in the hydro-cooling miner must be emptied after storage and transportation for more than 2 hours.

Rated flow: ≥ 11.6 L/min

Flow control accuracy: ± 10 %

Note: Temperature difference between inlet liquid and outlet liquid corresponds to 11.6 L/min is close to 10 ℃ @ normal mode, and 14 ℃ @ high performance mode.

Initial index requirements for coolant and coolant test indicators and cycles are shown in the following tables.

Table 1‑2

Itmes		Unit	Initial indices	Test method
pH (20 ℃)		—	7.0 – 8.7	ASTM D1287
Total number of bacterial colonies (microorganisms)		CFU/mL	< 100	AOAC 990
Sulfate		mg/L	< 10	ASTM D5827
Chloride		mg/L	< 20	ASTM D5827
Total hardness (CaCO3)		mg/L	< 20	ASTM D1126
Conductivity (20 ℃)		μs/cm	< 2000	ASTM D1125-23
Appearance		—	Clear liquid without precipitation	Visual inspection
Corrosion inhibitor		—	100 % active ingredients	—
Reserve alkalinity		mL	≥ 2.0	ASTM D11221
Glassware corrosion (70 °C)	Stainless steel	mg/pcs	± 10	ASTM D1384
	3003 aluminum alloy	mg/pcs	± 10
	6061 aluminum alloy	mg/pcs	± 10
Non-metal compatibility/mass change	EPDM	%	± 5	ISO 1817
	Fluorinated silicone rubber	%	± 5
	NBR	%	± 5

Table 1‑3

Items	Unit	Detection Indices	Test cycle	Reference test methods
pH (20 ℃)*	—	7.0 – 8.7	Every 2 months	ASTM D1287
Total number of colonies (microorganisms)*	CFU/mL	≤ 100	Every 6 months	AOAC 990
Sulfate	mg/L	≤ 10	Every 6 months	ASTM D5827
Chloride	mg/L	≤ 20	Every 6 months	ASTM D5827
Total hardness (CaCO3)	mg/L	≤ 20	Every 6 months	ASTM D1126
Conductivity (20 ℃)*	μs/cm	Increment ≤ 1500	Every 2 months	ASTM D1125-23
Appearance*	—	Clear liquid without precipitation	Every 2 months	Visual inspection
Copper ions*	mg/L	Increment ≤ 0.5	Every 6 months	ASTM D1971-02
Iron ions*	mg/L	Increment ≤ 0.5	Every 6 months	ASTM D1971-02
Aluminum ions*	mg/L	Increment ≤0.5	Every 6 months	ASTM D1971-02
Corrosion Inhibitor	—	Active ingredients ≥ 80 %	Every 6 months	Entrust corresponding suppliers to conduct tests
Reserve alkalinity	mL	≥ 2.0	Every 2 months	ASTM D11221

Note: * indicates that this index must be checked.