Can heat compress can help in regenerating joint cartilage? my point is that there will be more blood circulation thus it has the possibility to regen

Good point: Your point is well taken. Applying heat can increase blood flow to an area in general. To my knowledge, I have not seen any literature showing that applying heat would be helpful in cartilage regeneration; in which one if the hurdles to overcome is poor blood flow to the area. Good question.

You are probably right, but the effect will be minimal. If the heat compresses are hot enough, your local cells will release "heat shock proteins," the net effect of which can improve blood flow, anti-inflammatory cell pathways and proteins, and regeneration. If you are dealing with a cartilage/joint injury that is severe enough, there are more significant pro-regenerative options.