Abstract: A fluid machinery, a heat exchange equipment, and an operating method for the fluid machinery. The fluid machinery includes: an upper flange (50); a lower flange (60); a cylinder (20); a rotating shaft (10), the axis of the rotating shaft (10) being eccentric to the axis of the cylinder (20) and at a fixed eccentric distance; and a piston component (30), the piston component (30) being provided with a variable volume cavity (31). Because the eccentric distance between the rotating shaft (10) and the cylinder (20) is fixed, the rotating shaft (10) and the cylinder (20) rotate around the respective axes thereof during motion, and the position of the center of mass remains unchanged, so that the piston component is allowed to rotate stably and continuously when moving within the cylinder (20); and vibration of the fluid machinery is effectively mitigated.