Heat pump-based water harvesting systems, and methods of using thereof
Provided herein are water harvesting systems, as well as methods of making and using such systems, for capturing water from surrounding air using a design that reduces overall energy costs of the systems and improve water harvesting cycle efficiency. The systems and methods use sorbent materials, such as metal-organic frameworks, to adsorb water from the air. The systems and methods desorb this water in the form of water vapor, and the water vapor is condensed into liquid water and collected. The liquid water is suitable for use as drinking water.
1 . A water harvester, comprising:
a rotary device containing a sorbent, including:
at least one process sector,
said at least one process sector including a process air inlet and a process air outlet,
wherein process air flows from said process air inlet to said process air outlet through said at least one process sector,
wherein a sorbent in said at least one process sector adsorbs water from said process air flowing through said at least one process sector,
at least one reactivation sector,
said at least one reactivation sector including a reactivation air inlet and a reactivation air outlet,
wherein reactivation air flows from said reactivation air inlet to said reactivation air outlet through said at least one reactivation sector,
wherein said sorbent in said reactivation sector desorbs water into said reactivation air flowing through said at least one reactivation sector,
a drive assembly configured to rotate said rotary device;
a heat pump, comprising:
a compressor;
an expansion valve;
an evaporator;
a condenser;
a refrigerant fluid which flows sequentially within said compressor, said condenser, said expansion valve, and said evaporator,
wherein said condenser receives said reactivation air prior to flowing said reactivation air through said at least one reactivation sector,
wherein said evaporator receives said reactivation air from said at least one reactivation sector; and
a controller configured to receive one or more input parameters including one or more of: ambient temperature, ambient humidity, reactivation air temperature, reactivation air humidity,
wherein said controller implementing a water harvesting algorithm based on said one or more input parameters controls operation of said rotary device and said heat pump.
2 . The water harvester of claim 1 , wherein said condenser of said heat pump sufficiently heats said reactivation air to desorb water from said sorbent material in said at least one reactivation sector.
3 . The water harvester of claim 2 , wherein said evaporator of said heat pump sufficiently cools said reactivation air received from said reactivation sector to condense water from said reactivation air.
4 . The water harvester of claim 1 , wherein said rotary device comprises a carousel containing said sorbent, said carousel rotated by said drive assembly to sequentially dispose said sorbent in said at least one process sector or in said at least one reactivation sector.
5 . The water harvester of claim 1 , wherein said sorbent comprises one or more sorbents capable of adsorbing water from said process air.
6 . The water harvester of claim 5 , wherein said sorbent comprises one or more of: a metal organic framework, a zeolite, an alumina, a terephthalate, an isophthalate, or combinations thereof.
7 . The water harvester of claim 5 , wherein said sorbent comprises one or more of: MOF-303: Al(OH)(HPDC), wherein HPDC is 1H-pyrazole-3,5-dicarboxylate; CAU-10: Al(OH)(IPA), wherein IPA comprises isophthalate; MOF-801: Zr 6 O 4 (OH) 4 (fumarate) 6 ; MOF-841: Zr 6 O 4 (OH) 4 (MTB) 6 (HCOO) 4 (H 2 O) 2 ; Aluminum Fumarate: Al(OH)(fumarate); MIL-160: Al(OH)(FDA), wherein FDA is 2,5-furandicarboxylate; MIL-53: Al(OH)(TPA), where TPA is terephthalate; and Aluminum Phosphate: saAlPO4-LTA.SAPO-34, or combinations thereof.
8 . The water harvester of claim 1 , wherein said sorbent adhered to a substrate within said rotary device.
9 . The water harvester of claim 1 , further comprising a water tank disposed to receive water condensed from said reactivation air.
10 . The water harvester of claim 3 , wherein a portion of said reactivation air cooled by said evaporator of said heat pump supplied to a closed space as conditioned air.
11 . The water harvester of claim 1 , further comprising one or more fans adapted to generate a flow of said process air through said at least one process sector or said reactivation air through said at least one reactivation sector.
12 . The water harvester of claim 1 , wherein said controller controls said compressor based on the input parameters to achieve a pre-selected liters/day of water.
13 . The water harvester of claim 1 , wherein said controller controls said compressor based on the input parameters to achieve the lowest energy per liter of water.
14 . The water harvester of claim 1 , wherein said heat pump unit comprises an auxiliary condenser, wherein said refrigerant fluid flows sequentially to said condenser, then said auxiliary condenser, said expansion valve, said evaporator, and back to said compressor.
15 . The water harvester of claim 1 , wherein said controller can access energy loads for said condenser, said auxiliary condenser and said evaporator, wherein said controller operates to maintain a nearly constant energy load for each of said condenser, said auxiliary condenser and said evaporator to achieve desorption of water into said reactivation air flowing through said at least one reactivation sector and condense water from said reactivation air.