EFFECTS OF COOLING MEDIUM

Heat Transfer Coefficient of cooling medium

Medium	No	Cooling Medium  and Parameters	Heat Exchange Coefficient (w/m2k)	Remark
Air	1	Undisturbed air	50 – 80
Nitrogen	1	1 bar, forced	100 – 150
	2	6 bar, forced	300 – 400
	3	10 bar, forced	400 – 500
Helium	1	6 bar, forced	400 – 500
	2	10 bar, forced	550 – 600
	3	20 bar, forced	1000
Hydrogen	1	10 bar, forced	750
	2	20 bar, forced	1300
	3	40 bar, forced	2200
Salt	1	Quench salt 80˚C, still	600 - 900
	2	Quench salt 80˚C, forced	1000-1300
Oil	1	Quench oil 20˚C, 80˚C, still	1000 – 1500
	2	Quench oil 20˚C, 80˚C, forced	1800 – 2200
Polymer	1	Quench polymer 50˚C, still	1700 - 2500
	2	Quench polymer 50˚C, forced	2800 - 3500
Water	1	Water 15˚C, 25˚C, forced	3000 - 3800
	2	Brine 15˚C, 25˚C, forced

Influencing factors: 1. Medium            2. Thickness            3. Agitation
                             4. Temperature