A method(s) (600, 1100) for changing concentration of a solute within a solution is disclosed. The method (600) includes receiving a first stream of the solution at a state D.sub.in by a first heat and mass exchanger HMX1 and a second stream of the solution by a second heat and 5 mass exchanger HMX2. The method (600) includes processing the first stream of the solution by the HMX1 to generate a first dilute stream of the solution at a state D.sub.out. Further, the method (600) includes processing the second stream of the solution by the HMX2 to generate a first concentrate stream of the solution at a state Rout. The method (600) includes directing, at the initial phase, the first dilute stream of the solution from the processing unit to a first heat and mass exchanger 0 HMX1-n of a successive processing unit. The method (600) also includes receiving a first stream of the solution at a state D.sub.in-n by a second heat and mass exchanger HMX2-n.

An energy exchanger is provided. The exchanger includes a housing having a front and a back. A plurality of panels forming desiccant channels extend from the front to the back of the housing. Air channels are formed between adjacent panels. The air channels are configured to direct an air stream in a direction from the front of the housing to the back of the housing. A desiccant inlet is provided in flow communication with the desiccant channels. A desiccant outlet is provided in flow communication with the desiccant channels. The desiccant channels are configured to channel desiccant from the desiccant inlet to the desiccant outlet in at least one of a counter-flow or cross-flow direction with respect to the direction of the air stream.

Systems and methods for providing dehumidification to an enclosed space can include a dehumidification unit in a supply air plenum that receives return air and a regeneration unit in a scavenger air plenum that receives outdoor air. The system can operate in a wet mode and a dry mode, depending on outdoor air conditions and a relative humidity setpoint for the enclosed space. The dehumidification unit and regeneration unit are both operational in the wet mode to dehumidify the return air and regenerate dilute desiccant. In the dry mode, the dehumidification unit and regeneration unit are not needed, and dry outdoor air can be supplied to the enclosed space. A heat recovery system utilizes waste heat from either return air or scavenger air, depending on the operating mode, to heat the outdoor air before it is supplied to the enclosed space or before it is used for regenerating desiccant.

A liquid desiccant system includes a liquid desiccant loop having an absorber unit in fluid communication with a desorber unit and liquid desiccant flowing between the absorber unit and the desorber unit. The liquid desiccant system includes a supply airflow path passing through the absorber unit and forming an absorber liquid/air interface within the absorber unit and a conditioned airflow exiting the absorber unit. The liquid desiccant system includes a regeneration airflow path passing through the desorber unit and forming a desorber liquid/air interface within the desorber unit and an exhaust airflow exiting the desorber unit. A heat exchanger is thermally coupled to the supply airflow path for removing heat from supply airflow upstream of the absorber unit. A heat exchanger is thermally coupled to the regeneration airflow path adding heat to regeneration airflow upstream of the desorber unit.

A heat dissipation system apparatus and method of operation using hygroscopic working fluid for use in a wide variety of environments for absorbed water in the hygroscopic working fluid to be released to minimize water consumption in the heat dissipation system apparatus for effective cooling in environments having little available water for use in cooling systems. The system comprises a low-volatility, hygroscopic working fluid to reject thermal energy directly to ambient air. The low-volatility and hygroscopic nature of the working fluid prevents complete evaporation of the fluid and a net consumption of water for cooling, and direct-contact heat exchange allows for the creation of large interfacial surface areas for effective heat transfer. Specific methods of operation prevent the crystallization of the desiccant from the hygrosopic working fluid under various environmental conditions.

A liquid desiccant regenerator configured to produce a first output stream with a higher concentration of a liquid desiccant than a first input stream. The regenerator also produces a second output stream with a lower concentration of the liquid desiccant than a second input stream. Regeneration of the liquid desiccant in the liquid desiccant regenerator decreases a temperature of the liquid desiccant regenerator. The system includes an air contactor coupled to the first output stream and exposing an input air stream to the first output stream. The first output stream absorbs water from the input air stream to form at least one diluted output desiccant stream. A heat pump of the system is thermally coupled to move the heat from the first output stream to the liquid desiccant regenerator. The heat moved to the liquid desiccant regenerator increases an efficiency of the liquid desiccant regenerator.

A membrane assembly of an energy and vapor exchanger includes a gas-permeable membrane having a first major surface that faces a gas flow and a second major surface that faces a liquid desiccant flow. An inlet region is proximate an inlet edge of the gas-permeable membrane. The inlet region includes a vortex generator that creates a vortex in the gas flow as it moves from the inlet edge to an outlet edge of the gas-permeable membrane. The vortex enhances mixing of fluids along the gas-permeable membrane.

Integrated systems comprising both i) heat and mass exchange systems and ii) electrolysis stacks are disclosed, together with related methods of use. The disclosed systems cool and/or dehumidify air using two streams of salt solutions as liquid desiccants.

An absorption vacuum dehumidification system includes a vacuum section, an absorber, a desorber, a photovoltaic energy supply, a heat exchanger, a condenser, and a desiccant solution. The vacuum section has a feed side and a permeate side and comprising a hydrophilic membrane that separates the feed side than the permeate side. The absorber is connected to the permeate side of the vacuum section. The desorber is connected to the absorber to form a desiccant solution cycle path between the absorber and the desorber. The photovoltaic energy supply configured to power a heat source that provides hot liquid into the desorber. The heat exchanger is connected to the desiccant solution cycle path. The condenser is connected to the desorber. The desiccant solution flows along the desiccant solution cycle path.

A cooling system utilizes an organic ionic salt composition for dehumidification of an airflow. The organic ionic salt composition absorbs moisture from an inlet airflow to produce an outlet airflow with a reduce moisture from that of the inlet airflow. The organic ionic salt composition may be regenerated, wherein the absorbed moisture is expelled by heating with a heating device. The heating device may be an electrochemical heating device, such as a fuel cell, an electrochemical metal hydride heating device, an electrochemical heat pump or compressor, or a condenser of a refrigerant cycle, which may utilize an electrochemical pump or compressor. The efficiency of the cooling system may be increased by utilization of the waste heat the cooling system. The organic ionic salt composition may circulate back and forth or in a loop between a conditioner, where it absorbs moisture, to a regenerator, where moisture is desorbed by heating.