Q.Lime tree
7 years and still no fruit.

On average a citrus will began to produce fruit between 3 and 6 years of age, but this will depend on the cultivator, the environment and the health of the plant.
Flowering is not seasonal but is dependent on warm weather and regular watering.
Here are some links that will help you pinpoint the possible issues.
https://www.gardeningknowhow.com/edible/fruits/lime/lime-tree-tips-care-of-lime-trees.htm
https://www.gardeningknowhow.com/edible/fruits/lime/potted-lime-trees.htm
https://www.gardeningknowhow.com/edible/fruits/lime/watering-limes-in-containers.htm
https://www.gardeningknowhow.com/edible/fruits/lime/reasons-and-fixes-for-lime-tree-not-producing-blossoms-or-fruit.htm