I suppose you are referring to Qi Huo, Qi Ding or Qi Lun. Some claim these are part of Shen Gong, but several scholars have pointed out - like Jerry Alan Johnson (who is a teacher of mine), that these are latter additions to Taoism, at a much later point in time, very likely by Buddhist influence as Buddhists refer to the imagery as wheels more than the Hindu Yogins who originally and primarily dealt with Chakras and referred to them more or less unanimously with the lotus imagery. These are not practically used in any authentic Taoist Qigong, Neigong or Shengong systems.
The one person who keeps referring to this is Damo Mitchell. In 2009, I took a class on Medical Qigong from Rob Aspell and Damo was assisting him. When these parallels to Chakras was brought up, I raised the same point and asked him how exactly were they used in a Shen Gong infrastructure and he did not really have a clear or convincing answer. I also took a few classes in Nanpai Taiji from Damo himself, who no doubt is a great teacher when it comes to practice, but found him severely lacking in terms of scholastic aptitude. He kind of makes up things as he goes lol. The dead giveaway is Kuan Shu Lun or the wheel of great Compassion, which is directly lifted from a Vajrayana Tantra.
I can read some Mandarin and none of the popular or well-established Daoist treatises refer to this symbology or their utility within a Daoist Neigong framework. So, I am inclined to believe that he picked it up from his Longmen Pai days which is a rather eclectic (infamously) system and not a gold standard of anything. Considering him to be the only person who seems to vaguely mention it, I would not take it as part of any serious Daoist training.
Also, even according to Mitchell himself, he clearly distinguishes the three cauldrons from the seven wheels - quote “There is a common error within the Qi Gong community whereby the three Dan Tian are believed to be the same thing as the seven chakras, albeit three of them. This is not the case. The three Dan Tian exist as an aspect of the energetic matrix with associated physiological components. The seven chakras exist within the spiritual range of frequencies with some associated tethers into the energetic realm. Though they have no literal form, the seven chakras are experienced as being much smaller than the Dan Tian and have a very clear quality to them that can only really be experienced when at the stage of harmonising the Shen.”
If you belong to a school other than Damo Mitchell’s and do use the Chakra system in your shengong, I would be glad to learn and correct my statement.