Device comprising a sealed enclosure (18, 22, 26, 28) containing a fluid of which the liquid phase is in balance with the vapor phase in a predetermined range of temperatures, the enclosure (18, 22, 26, 28) being divided between a first volume (18, 22, 26) and a second volume communicating through a first fluid circulating passage (32, 34) allowing some of the calorie conveying fluid vapor phase to penetrate into the second volume by rising, the second volume comprising a tank connecting to the passage (32, 34) and capable of containing fluid in the liquid phase when the device is in a predetermined position with respect to the direction of gravity (g) in which device: • the second volume contains a non-condensable gas in the predetermined temperature range and which is not soluble in the liquid phase of the fluid; • the said gas and the second volume are chosen so that when the device is placed in the predetermined position, the said gas: ∘ fills at least partially the first circulating passage (32, 34) when the gas temperature is less than a predetermined temperature T max lim of the temperature range; and ∘ liberates the first circulating passage (32, 34) when the gas temperature is higher than the first predetermined temperature T max lim. Characterized in that: • the tank is capable of containing the integrity of the fluid in its liquid phase for a second predetermined temperature T max coup of the temperature range, higher than the first temperature T max lim. • and in that the device has a second passage (30, 50) allowing the passage of the liquid phase of the calorie conveying fluid from the tank to the first volume, by gravity, with a load loss leading to a mass flow rate of the liquid phase which is strictly lower than the mass flow rate of the vapor phase defined by the passage of the fluid circulation (32, 34) in such a way as to induce the storage of the insularity of the liquid phase of the calorie conveying fluid in the tank for a temperature higher than the second predetermined temperature T max coup. • the second volume contains a non-condensable gas in the predetermined temperature range and which is not soluble in the liquid phase of the fluid; • the said gas and the second volume are chosen so that when the device is placed in the predetermined position, the said gas: ∘ fills at least partially the first circulating passage (32, 34) when the gas temperature is less than a predetermined temperature T max lim of the temperature range; and ∘ liberates the first circulating passage (32, 34) when the gas temperature is higher than the first predetermined temperature T max lim. ∘ fills at least partially the first circulating passage (32, 34) when the gas temperature is less than a predetermined temperature T max lim of the temperature range; and ∘ liberates the first circulating passage (32, 34) when the gas temperature is higher than the first predetermined temperature T max lim. • the tank is capable of containing the integrity of the fluid in its liquid phase for a second predetermined temperature T max coup of the temperature range, higher than the first temperature T max lim. • and in that the device has a second passage (30, 50) allowing the passage of the liquid phase of the calorie conveying fluid from the tank to the first volume, by gravity, with a load loss leading to a mass flow rate of the liquid phase which is strictly lower than the mass flow rate of the vapor phase defined by the passage of the fluid circulation (32, 34) in such a way as to induce the storage of the insularity of the liquid phase of the calorie conveying fluid in the tank for a temperature higher than the second predetermined temperature T max coup.