What are these pipes on an Avro Vulcan?
Although it is difficult to say from old photos, the tubes doesn't seem to be visible on the prototype or early Vulcans. 

Another Vulcan, XH558 started life as a B2 and are fitted with Olympus 202 engines. Looking at a photo of it there are what appear to be intakes on each engine, as seen here. I don't know what engines the Duxford Vulcan has, but according to Wikipedia the 202 was the definitive version for the Vulcan, with the exception of some aircraft which received the 301. As far as I can tell, one of the features with the 202 was that it had a redesigned oil separator breathing system. 

Such features require air inlet as well as an outlet for the vented gases, could this be related to that system?