Process for producing cold and/or heat by means of an absorption cycle

Claim 1

Process for producing cold and/or heat according to an absorption cycle operated with a working fluid (F), a solvent (S) for said working fluid and an auxiliary fluid (H), characterized by the steps of: (a) contacting, in an absorption/condensation step, a liquid phase of solvent (S) with a gas phase comprising both the working fluid (F) and a fluid (H), so as to obtain a solution of the fluid (F) in the solvent (S) and a liquid phase of fluid (H), the liquid phase of fluid (H) being at least partly immiscible with the solution of the fluid (F) in the solvent (S) and the fluid (H) being a fluid which can vaporize in the conditions of step (e) and condense in the conditions of step (a), the absorption heat of the fluid (F) in the solvent (S) and the condensation heat of the fluid (H) being transferred to an external fluid, (b) separating the solution of fluid (F) in the solvent (S) from the liquid phase of fluid (H), (c) supplying the solution of fluid (F) in solvent (S), recovered from the step (b), to a desorption step and subjecting said solution to desorption conditions, the desorption heat being supplied by an external fluid, so as to form a liquid phase of decreased content of fluid (F) and a vapor phase of high content of fluid (F), and recycling said liquid phase of decreased content of fluid (F) to the absorption/condensation step (a) to form the liquid phase of solvent (S), (d) condensing at least a portion of the vapor phase of high content of fluid (F), recovered from the desorption step (c), and delivering heat to an external fluid, to obtain a liquid condensation phase, (e) admixing at least a portion of the liquid condensation phase, obtained in step (d), with at least a portion of the liquid phase of fluid (H) recovered from step (b), vaporizing at least a portion of the resultant mixture with heat supplied from an external fluid, the operating conditions being so selected as to allow vaporization of at least a portion of the fluid (F) and at least a portion of the fluid (H), and (f) recycling the resultant gas phase to the step (a), the fluid (H) being so selected that the maximum variation of its vapor pressure be comprised between 40 and 80% of the minimum vapor pressure of the fluid (F), and the ratio of the molar feed rate of fluid (H) to the molar feed rate of fluid (F) representing at least 80% of the ratio of the vapor pressure of the fluid (H) at the end of the vaporization step (a) to the vapor pressure of the fluid (F) at the beginning of the vaporization step, both molar feed rates being determined at the beginning of the vaporization step.