A liquid absorption refrigeration system and a tube and channel heat exchanger include: an absorber section to contain a saturated strong solution; a pump connected to an outlet of the absorber section to receive saturated strong solution therefrom; a regenerator section connected to an outlet of the pump to receive a flow of pressurized saturated strong solution therefrom; an expansion device connected to an outlet of the regenerator section to receive a flow of subcooled strong solution therefrom; an evaporator section connected to an outlet of the expansion device to receive the subcooled strong solution therefrom, the evaporator section connected to the absorber section to return strong solution thereto; and a condenser section connected to the evaporator section to receive a refrigerant evaporated from the subcooled strong solution in the evaporator, the condenser section connected to the absorber section to return liquid refrigerant thereto.

A multi-stage adsorber device including a plurality of adsorption stages distributed in sequence, each including an adsorber coupled to an adjacent vapor chamber, wherein the adsorber of each following adsorption stage is thermally coupled to the vapor chamber of a preceding adsorption stage via a heat transfer structure. A heating stage is thermally coupled to a first one of the adsorption stages to selectively provide thermal energy to the adsorbers, while a cooling stage is thermally coupled to a final one of the adsorption stages to selectively cause condensation of desorbed vapor in the vapor chambers. The adsorber device further includes a cooling circuit having first and second cooling sections to selectively cause circulation of a cooling fluid through the cooling stage and through each of the adsorbers, respectively. During a desorption cycle, the heating stage is activated to induce vapor desorption in the adsorbers, resulting in desorbed vapor flowing from each adsorber into the adjacent vapor chamber, and cooling fluid circulates exclusively through the cooling stage via the first cooling section. As a result, desorbed vapor condenses along a surface of the heat transfer structure, during the desorption cycle, releasing latent heat that is transferred to the adsorber of the following adsorption stage. During an adsorption cycle, the heating stage is deactivated to allow vapor adsorption into the adsorbers, and cooling fluid circulates through both the cooling stage and each of the adsorbers via the first and second cooling sections. Uses of such adsorber device are especially contemplated for chilling and/or atmospheric water harvesting applications.

An evaporator for an absorption heat pump or a single coolant cooling process comprises a number of stacked plates provided with a pressed pattern to hold the plates on a distance from one another to form a heat exchanging strip, vapor leading spaces and outer walls, the heat exchanging strip being designed such that flow channels are formed by internal surfaces of the strip, said flow channels connecting a heat carrier inlet and a heat carrier outlet, wherein a coolant forms a falling film on external surfaces of the heat carrier channels by being provided above the heat carrier channels by a coolant inlet, wherein coolant being vaporized from the external surfaces by heat from a heat carrier flowing from the inlet to the outlet rapidly enters the vapor leading spaces. The vapor leading spaces are provided between the heat exchanging strip and the outer walls.