cooling tower vs cooling system

cooling tower and cooling system both are nouns.

Word	Noun	Adjective	Verb	Adverb
cooling tower	Yes	No	No	No
cooling system	Yes	No	No	No

As nouns, cooling system is a hypernym of cooling tower; that is, cooling system is a word with a broader meaning than cooling tower:

cooling tower: a cooling system used in industry to cool hot water (by partial evaporation) before reusing it as a coolant
cooling system: a mechanism for keeping something cool

Other hypernyms of cooling tower include cooling.

cooling tower (noun)	cooling system (noun)
a cooling system used in industry to cool hot water (by partial evaporation) before reusing it as a coolant	a mechanism for keeping something cool
	equipment in a motor vehicle that cools the engine