Abstract: The disclosure relates to mass transfer assemblies for heating ventilation and cooling systems. In some examples, a mass transfer apparatus includes a stack of plates defining alternating conditioning channels and exhaust channels. The mass transfer apparatus also includes a fluid distribution system that includes a conditioning supply line defined in part by a first hole in an upper portion of each of the plates, and a working supply line defined in part by a second hole in the upper portion of each of the plates. The conditioning supply line supplies a conditioning fluid to the conditioning channels and the working supply line supplies a working fluid to the exhaust channels. The fluid distribution system also includes a conditioning return line that collects the conditioning fluid, and a working return line that collects the working fluid, each collection at a lower portion of each of the plates.

Abstract: The disclosure relates to fin inserts for heat and mass exchangers and corresponding methods. For instance, in some examples, a fin insert to a heat and mass exchanger includes a generally rigid, longitudinally-extending member that includes a top portion and side portions. The side portions may be disposed on opposite sides of the top portion, and may include a concave shape facing away from one another. The side portions may further are each be positioned around a portion of a respective heat transfer tube.

Abstract: A liquid desiccant regeneration system and method of liquid desiccant regeneration are described. The liquid desiccant regeneration system includes a liquid desiccant regenerator having an engine producing a heated exit stream, and at least one dehydrating tube comprising a first water vapor permeable wall. A low concentration liquid desiccant stream feeds into the liquid desiccant regenerator, while a high concentration liquid desiccant stream exiting the liquid desiccant regenerator. A carrier stream and the low concentration liquid desiccant are in contact with opposite sides of the first water vapor permeable wall, and the low concentration liquid desiccant stream is heated by heat from the heated exit stream to drive water from the low concentration liquid desiccant stream through the first water vapor permeable wall to the carrier stream to form a humidified carrier stream.

Abstract: A composite flow field element, such as a separator plate used in a high temperature air-cooled fuel cell assembly, preferably includes a metal sheet substrate of non-uniform thickness, such as a mesh, and flexible graphite layers bonded to the metal mesh substrate by an electrically conductive bonding agent.