Editing Compressed-air energy storage (section)

=== Other ===
One implementation of isothermal CAES uses high-, medium-, and low-pressure pistons in series. Each stage is followed by an airblast [[venturi pump]] that draws ambient air over an air-to-air (or air-to-seawater) heat exchanger between each expansion stage. Early compressed-air [[torpedo]] designs used a similar approach, substituting seawater for air. The venturi warms the [[exhaust gas|exhaust]] of the preceding stage and admits this preheated air to the following stage. This approach was widely adopted in various compressed-air vehicles such as [[H. K. Porter, Inc.]]'s mining [[locomotives]]<ref>{{cite web  |author=Douglas Self   |author-link=Douglas Self   |url=http://www.douglas-self.com/MUSEUM/TRANSPORT/comprair/comprair.htm |title=Compressed-Air Propulsion |access-date=2014-05-11}}</ref> and trams.<ref name="autogenerated1">{{cite web |url=http://www.aircaraccess.com/images/3stage%201.jpg |title=3-stage propulsion with intermediate heating |access-date=2014-05-11 |archive-url= https://web.archive.org/web/20151031053915/http://www.aircaraccess.com/images/3stage%201.jpg |archive-date=October 31, 2015 |url-status=dead }}</ref> Here, the heat of compression is effectively stored in the atmosphere (or sea) and returned later on.{{citation needed|date=April 2021}}