Two-phase precooling method for air conditioning systems
Patent Information
- Application Number
- JP2024556033
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2021-11-15
- Filing Date
- 2022-11-15
- Publication Date
- 2025-11-21
AI Technical Summary
Existing air conditioning systems are inefficient in dehumidifying outside air before introducing it into a conditioned space, leading to increased moisture content and perceived temperature, and separate dehumidification processes consume excessive energy.
A two-phase process involving a heat exchanger with dry and wet channels to pre-cool and dehumidify outside air, where the wet channel evaporates liquid to cool the dry channel, reducing the need for additional energy and enhancing dehumidification efficiency.
The system effectively pre-cools and dehumidifies outside air, reducing the load on the dehumidifier and minimizing energy consumption while maintaining comfort in the conditioned space.
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Abstract
Description
[Technical field]
[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of and priority to U.S. Provisional Application No. 63 / 279,528, filed November 15, 2021, the contents of which are incorporated herein by reference. [Background technology]
[0002] The present disclosure relates to systems and methods for improving the efficiency and effectiveness of existing dehumidifiers.
[0003] Air conditioning systems generally provide some degree of dehumidification of the air as part of the cooling process. These systems may be used to cool the air within an enclosed conditioned space. Alternatively, such systems may be used to cool exterior air prior to introduction into the conditioned space. However, such systems are generally inefficient, and as a result, when exterior air is introduced into a conditioned room, it may introduce significant amounts of moisture that the air conditioning system may not be able to address quickly or completely. This introduction of exterior moist air increases the perceived temperature of the conditioned space, reducing the comfort of occupants therein.
[0004] These problems are typically mitigated by using a separate dehumidification process (beyond the cooling system) on the outside air before it is introduced into the conditioned room, however, such dehumidification processes are typically inefficient and require the consumption of large amounts of additional energy.
[0005] Thus, there exists a long felt and currently unmet need for a system that allows for more efficient dehumidification of outside air prior to introduction into a conditioned space. Summary of the Invention [Problem to be solved by the invention]
[0006] The present disclosure relates to systems and methods for controlling the temperature and humidity of a defined space. More specifically, the present disclosure is directed to systems and methods employing a two-phase process for pre-cooling air prior to dehumidification. In one embodiment of the present disclosure, outside air is passed through a dry channel of a heat exchanger for pre-cooling before undergoing dehumidification. The additional energy requirements for the heat exchanger are reduced or eliminated by simultaneously passing conditioned air through a wet channel of the heat exchanger before discharging the conditioned air to the surroundings. Liquid in the wet channel evaporates into the exhausted conditioned air, cooling the channel. The wet channel is thermally coupled to the dry channel, thereby cooling the dry channel and initially cooling and dehumidifying the outside air before it enters the dehumidifier. [Brief description of the drawings]
[0007] The following detailed description is given by way of example, and is not intended to limit the disclosure to only the particular embodiments described, and may be best understood in conjunction with the accompanying drawings. [Figure 1] FIG. 1 is a schematic diagram of an air conditioning system including a heat exchanger, a dehumidifier, a conditioned space, and airflow into and out of the system. [Diagram 2] FIG. 2 shows a first embodiment of the system of FIG. 1 with a heat exchanger having multiple channels. [Diagram 3] FIG. 3 shows a second embodiment of the system of FIG. 1 with a heat exchanger having multiple channels. [Figure 4] FIG. 4 shows a third embodiment of the system of FIG. 1 with an exhaust fan and a supply fan.
[0008] For purposes of facilitating and understanding the principles disclosed herein, reference will now be made to the preferred embodiment illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is intended herein. Such changes and further modifications in the illustrated apparatus, and such further applications of the principles disclosed and illustrated herein, as would normally occur to one skilled in the art to which this disclosure pertains, are contemplated. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0009] The inventors of the present disclosure have created a new method for controlling the air temperature, air flow, and humidity in a space that includes an air conditioning system 100.
[0010] FIG. 1 illustrates an air conditioning system 100 for an air conditioned room 106, according to an embodiment of the present disclosure. As illustrated, the air conditioning system 100 includes a heat exchanger 102 and a dehumidifier 104. The heat exchanger 102 and the dehumidifier 104 are coupled such that air is delivered from the heat exchanger 102 to the dehumidifier 104. The dehumidifier 104 is in turn coupled to the air conditioned room 106. In the embodiment illustrated in FIG. 1, the heat exchanger 102 and the dehumidifier 104, and the dehumidifier 104 and the air conditioned room 106 are coupled to each other using pipes, ducts, or another physical connection that generally does not pass air, respectively, such that substantially all of the air passing through the heat exchanger 102 is received by the dehumidifier 104, and substantially all of the air received by the dehumidifier 104 is delivered to the room 106.
[0011] As shown, the heat exchanger 102 receives and pre-cools ambient air 124. During pre-cooling, the temperature of the air 124 is reduced, which causes the water vapor in the air to condense into liquid form and removes water vapor from the air 124.
[0012] In one embodiment, the heat exchanger operates as a passive heat exchanger 102 (as described further herein) while also including an active cooling system that further cools the air during the pre-cooling step.
[0013] After exiting the heat exchanger 102, the pre-cooled and partially dehumidified air then passes through a dehumidifier 104, which further dehumidifies the pre-cooled air. The dehumidifier 104 may comprise a membrane dehumidifier, a desiccant dehumidifier, a mechanical compression dehumidifier, or other types of dehumidification systems known in the art. After being further dehumidified, the air is sent from the dehumidifier 104 to a conditioned room 106.
[0014] In an alternative embodiment, the dehumidifier 104 may be omitted and the pre-cooled air may be sent directly from the heat exchanger 102 to the conditioned room 106. In a second alternative embodiment, the dehumidifier 104 may be combined with the heat exchanger 102 such that a single device performs both functions described herein.
[0015] 1, the conditioned room 106 receives dehumidified and pre-cooled air from the dehumidifier 104. The air then passes through the room at the desired temperature before exiting the room as exhaust air 120.
[0016] In alternative embodiments, additional cooling systems may be used to further cool the air before introduction into conditioned space 106 and / or to cool the air within the conditioned space. In one such alternative embodiment, a separate air conditioning system (such as a central air conditioner) cools the air within the conditioned space. In another such alternative embodiment, a further air conditioning system is employed to further cool the pre-cooled air before it is introduced into the conditioned space.
[0017] As shown, air from the conditioned chamber 106 is exhausted from the conditioned chamber 106 as exhaust air 120. The exhaust air 120 passes through a heat exchanger 102 before being released to another environment. In an embodiment, fresh outside air is continuously introduced into the conditioned space while a corresponding amount of exhaust air 120 is exhausted, constantly ventilating the conditioned space while maintaining the pressure within the conditioned chamber 106 substantially unchanged.
[0018] 2 illustrates an embodiment of a system 200 including a heat exchanger 202 having at least one dry channel 208 and at least one wet channel 210. Hereinafter, the singular use of "dry channel" and "wet channel" includes both the plural or singular use of these terms.
[0019] In the embodiment shown in FIG. 2, outside air is drawn into and passes through the dry channel 208 before being supplied to the dehumidifier 104. Similarly, exhaust air 120 passes through the wet channel 210 before being exhausted. The walls 214a, 214b of the dry channel and the walls 214c, 214d of the wet channel are thermally coupled such that a change in temperature of any one wall 214 results in a corresponding change in temperature of the other wall 214. In the illustrated embodiment, the surfaces of the walls of the wet and dry working channels may be connected to form a shared wall made of a thermally conductive material 217. Each channel 208, 210 forms an enclosed space leading from a respective air inlet 213a, 213b to an air outlet 215a, 215b. Air flows from each inlet through the respective channel to the outlet. The walls 214c, 214d of the wet channel are coated with a liquid. In the illustrated embodiment, the walls 214c, 214d are coated with water. As the exhaust air 120 passes through the wet channels 210, water from the walls 214c, 214d evaporates, thereby reducing the temperature of the walls 214c, 214d. Because the exhaust air has already been conditioned, it typically has a low moisture content, thus resulting in significant evaporation. As the walls of the wet channels 210 cool, heat is transferred from the dry channels 208 to the wet channels 210. Outside air passing through the dry channels 208 is cooled by contact with the dry channel walls 214a, 214b, which condense and remove moisture from the air.
[0020] 2, the fluid connection between the dry channel 208 and the wet channel 210 allows the supply of liquid in the wet channel 210 to be continuously replenished with moisture from the air passing through the dry channel 208. In an alternative embodiment, the fluid connection is completely passive, such that no external energy is required to transport moisture from the dry channel 208 to the wet channel 210.
[0021] The dry channel 208 and the wet channel 210 can be arranged in a number of configurations. As will be apparent to one skilled in the art, a combination of these embodiments and other passive transport techniques can be used to effectively transfer moisture from the dry channel 208 to the wet channel 210 while preventing backflow of moisture from the wet channel 210 to the dry channel 208. In one embodiment, the dry channel 208 is positioned above the wet channel 210 such that gravity transfers moisture from the dry channel 208 to the wet channel 210. In an alternative embodiment, the fluid connection is structured such that capillary action provides moisture transfer from the dry channel 208 to the wet channel 210. Regardless of the arrangement of the dry channel 208 and the wet channel 210, the walls 214a, 214b of the dry channel 208 may be coated with a hydrophobic material such that water that collects thereon is driven through the fluid connection to the wet channel 210.
[0022] In an alternative embodiment, an active source, such as a pump, is used to effect the movement of moisture from the dry channels 208 to the wet channels 210. Alternatively, both active and passive mechanisms are combined to ensure continuous and efficient movement of water from the dry channels 208 to the wet channels 210.
[0023] 2, an external source is used to replenish the water in the wet channel 210. The external source may comprise a connection to a local water supply and / or distilled water obtained from a reservoir.
[0024] In one embodiment, the heat exchanger 202 comprises a plurality of dry channels 208 and a plurality of wet channels 210. In one embodiment, each dry channel 208 is thermally coupled to a single wet channel 210. In an alternative embodiment, a plurality of dry channels 208 are thermally coupled to one or more wet channels. In a further embodiment, alternating successive wet channels 210 and dry channels 208 are spaced apart such that their respective walls are thermally coupled. In each of the above-described embodiments, a channel plate can act as a wall of the heat exchanger 202 and function to thermally couple the dry channels 208 and the wet channels 210. In other embodiments, the channels 208, 210 are configured in an alternative arrangement that allows for heat transfer between the channels.
[0025] Although the above discussion refers to the dry channels 208 and the wet channels 210 as having "walls" 214, it will be understood that any three-dimensional arrangement can be used. In one embodiment, the channels 208, 210 each comprise a cylinder. Substantially all of the walls of the wet channels 210 may be coated with water. Alternatively, the channels 208, 210 may comprise a rectangular prism. In such an embodiment, only the "floor" of the wet channel may be coated with water. As will be apparent to one skilled in the art, the cooling capacity of the system 200 can be selected by adjusting the number of channels 208, 210 and / or the contact area between the walls 214 of the channels 208, 210 and the air passing through the channels 208, 210. A larger contact area increases the amount of evaporation and / or condensation, thereby allowing both the degree of pre-cooling and the amount of dehumidification to be adjusted based on the desired capacity of the system.
[0026] In a preferred embodiment, the liquid 216 used in the wet working channel 210 is water. In alternative embodiments, any liquid may be used to facilitate heat transfer between the channels.
[0027] In the preferred embodiment of FIG. 2, exhaust air 220 leaves the air conditioning chamber 206 and is sent to the wet working channel 210. As the exhaust air passes through the wet working channel 210, it absorbs the liquid 216 on the channel walls 214. The absorption of the liquid 216 removes heat from the wet channel walls 214 and cools the shared wall 217. The shared wall 217 then cools the dry working channel 208, as well as the outside air 224 passing through the dry working channel 208. As the outside air 124 cools, its moisture content decreases. The partially cooled and dehumidified outside air 226 is then sent to the dehumidifier 204 where it is further dehumidified. After passing through the dehumidifier, the outside air 228 is sent to the air conditioning chamber 106 to compensate for the cooling and humidity load in the air conditioning chamber before reaching parameters for exhaust and exiting the air conditioning chamber. The exhaust air 120 is then conveyed to the working channels 208, 210 and the previous cycle begins again.
[0028] By placing the two-phase heat exchanger 202 before the dehumidifier 104, the capacity requirements of the dehumidifier 104 are dramatically reduced because the majority of the cooling and dehumidification process can occur in a pre-cooling process 226 before the air reaches the dehumidifier 104. In an embodiment, the degree of pre-cooling provided by the heat exchanger 202 completely eliminates the need for subsequent dehumidification 204.
[0029] In one embodiment of the heat exchanger 202, the plates and walls 214 are constructed from a nonwoven material, such as a polyethylene terephthalate (PET) nonwoven material. In another embodiment, the plates and walls 214 are constructed from a material suitable for heat exchange, including, but not limited to, metals and metal alloys, such as aluminum, copper, carbon steel, stainless steel, nickel alloys, and titanium. In another embodiment, the plates and walls 214 are constructed from a ceramic material.
[0030] In an additional embodiment, the heat exchanger 202 may further comprise plates and walls 214 that provide an extended surface area to increase the contact area between the air and the water. To reduce the thickness of the liquid on the surface of the walls, the walls 214 may be coated with a hydrophilic surface.
[0031] 3 illustrates a second embodiment of an air conditioning system 300 in which the heat exchanger 302 includes a second dry working channel 318 for further pre-cooling the exhaust air 120. As will be apparent to one of ordinary skill in the art, any number of wet and / or dry channels may be used based on the desired capacity of the system.
[0032] 3, the exhaust air 320 is routed to an additional dry working channel 318 before moving to the wet working channel 210. In this embodiment, the heat exchanger 302 comprises alternating, successively thermally coupled wet and dry working channels 208, 210, 318.
[0033] In the embodiment of FIG. 3, the air conditioning system 300 includes the same elements and steps as the described embodiment of FIG.
[0034] FIG. 4 illustrates a system 400 that is generally similar to the embodiment of FIG. 1 described above, unless otherwise noted. In the system 400, an exhaust fan 440 is disposed along the path of movement of the exhaust air 120. The exhaust fan 440 functions to exhaust the exhaust air 120 from the conditioned space 106 and drive the exhaust air through the wet channels of the heat exchanger 402. Similarly, a supply fan 450 is disposed along the path of movement of the outside air 124 into the dry channels of the heat exchanger 402. As will be apparent to one skilled in the art, any number of exhaust fans 440 and supply fans 450 may be used depending on the requirements of the system. Furthermore, the fans 450, 440 may be disposed at one or more points along the respective supply and exhaust air paths to achieve the desired movement of air through the system. In one embodiment, only a single fan is used to achieve the desired movement.
[0035] In the present disclosure, the heat exchangers 102, 202, 302, 402 act passively on the exhaust air and outside air. No energy is required for the cooling and dehumidification that occurs during the heat exchange process. In an alternative embodiment, in addition to the passive cooling and dehumidification described above, active cooling and dehumidification may also be performed in the heat exchangers, thereby improving the efficiency of conventional active cooling systems while still ensuring that the desired degree of cooling is consistently achieved.
[0036] Although preferred embodiments of the present disclosure have been described in detail, it should be understood that the present disclosure as defined by the above paragraphs is not limited to the specific details set forth in the above description, as many variations in form thereof are possible without departing from the spirit or scope of the present disclosure.
Claims
1. An air conditioning system that conditions the air in a space, Air-conditioned space and Dehumidifier and a heat exchanger; the heat exchanger has a first channel having a first inlet configured to take exhaust air from the conditioned space and a first outlet configured to discharge the exhaust air to an outdoor environment, and a second channel having a second inlet configured to take outdoor ambient air from the outdoor environment and a second outlet configured to deliver the outdoor ambient air to the dehumidifier; a wall of the first channel and an adjacent wall of the second channel form a shared, thermally coupled wall comprised of a single, impervious plate; a first surface of the thermally coupled wall in the first channel is coated with a liquid, whereby passage of exhaust air through the first channel evaporates at least a portion of the liquid coated on the first surface of the thermally coupled wall, thereby reducing the temperature of the first surface of the thermally coupled wall; evaporation of the liquid transfers heat between the first surface of the thermally coupled wall and a second surface of the thermally coupled wall disposed within the second channel, thereby reducing the temperature of the first surface of the thermally coupled wall, which reduces the temperature of the second surface of the thermally coupled wall and cools the outdoor ambient air traversing the second channel to generate pre-cooled air; the dehumidifier dehumidifies the pre-cooled air received from the second channel to a desired level and sends the dehumidified air to the air-conditioned space; The conditioned air circulates within the conditioned space and exits the conditioned space as exhaust air. An air conditioning system characterized by:
2. The first inlet is adjacent to a first end of the heat exchanger. The first outlet is adjacent to a second end of the heat exchanger. a second inlet adjacent the second end of the heat exchanger; a second outlet proximate the first end of the heat exchanger; and The outdoor ambient air drawn through the second inlet of the second channel comprises a mixture of outdoor air and exhaust air exhausted through the first outlet of the first channel.
2. The air conditioning system according to claim 1.
3. The dehumidifier is selected from the group consisting of a membrane dehumidifier, a desiccant dehumidifier, or a mechanical compression dehumidifier.
2. The air conditioning system according to claim 1.
4. The heat exchanger includes a third channel that pre-cools the exhaust gas before it passes through the first channel.
2. The air conditioning system according to claim 1.
5. The liquid consists of water 2. The air conditioning system according to claim 1.
6. 6. The air conditioning system of claim 5, wherein the system further comprises a connection to an external water supply for replenishing the water coated on the first surface of the thermally coupled wall.
7. The walls of the first and second channels are made of a plastic, a metal, a metal alloy, a ceramic material, or a combination thereof.
2. The air conditioning system according to claim 1.
8. an exhaust fan that draws exhaust air from the air-conditioned room into the first channel; The air conditioning system of claim 1 , further comprising a supply fan that draws ambient air into the second channel.
9. 1. A method of conditioning a space by circulating air through a heat exchanger, a dehumidifier, and the conditioned space, comprising: drawing ambient air through a first dry channel of the heat exchanger to precondition the ambient air; passing the preconditioned ambient air through the dehumidifier to generate conditioned air and delivering the conditioned air to the conditioned space; passing the conditioned air through the conditioned space and directing the conditioned air out of the conditioned space as exhaust air; moving the exhaust air from the conditioned space through a wet channel of the heat exchanger, the wet channel and a first dry channel having a shared thermally coupled wall, the exhaust air causing liquid to evaporate from a surface of the thermally coupled wall in the wet channel to reduce a temperature of the first dry channel; the liquid coating the surfaces of the thermally coupled walls within the wet channels; the evaporation of liquid from the thermally coupled walls removes heat from the thermally coupled walls to reduce the temperature of the first dry channel; The reduction in temperature of the first dry channel pre-cools and partially dehumidifies the pre-conditioned ambient air as it passes through the first dry channel before sending the pre-conditioned ambient air to the dehumidifier. A method for air conditioning a space, comprising:
10. The ambient air drawn through the first dry channel comprises a mixture of outdoor air from the outdoor environment and exhaust air exhausted through the wet channel.
10. A method of ventilating a space according to claim 9.
11. The dehumidifier is selected from the group consisting of a membrane dehumidifier, a desiccant dehumidifier, or a mechanical compression dehumidifier.
10. The method for adjusting a space according to claim 9.
12. The thermally coupled wall is constructed from a single non-penetrating plate.
10. The method for adjusting a space according to claim 9.
13. The method of conditioning a space as recited in claim 12, further comprising a pre-cooling step in which a second dry channel pre-cools the exhaust air before it enters the wet channel.
14. and further comprising replenishing the wet channel with a supply of the liquid, the wet channel including a connection to an external supply of the liquid to replenish the supply of the liquid in the wet channel.
14. The method of adjusting a space according to claim 13.
15. A heat exchanger as a system for conditioning air, a wet channel that draws exhaust air from the air conditioning chamber through an inlet and expels said exhaust air through an outlet located at an opposite end; a first dry channel sharing a wall thermally coupled with the wet channel, the first dry channel being positioned to draw in ambient air through an inlet and exhaust the ambient air through an outlet located at an opposite end of the first dry channel toward a dehumidifier; an operative connection between the dehumidifier and the air conditioning chamber for directing ambient air through the dehumidifier to produce dehumidified air that exits the air conditioning chamber as exhaust air that is delivered to the air conditioning chamber; the thermally coupled wall surfaces within the wet channel are coated with a liquid; When the temperature of the exhaust air is lower than the ambient air, passage of the exhaust air through the wet channel evaporates liquid from the thermally coupled walls to cool the wet channel, and the first dry channel transfers heat to the wet channel to condition the ambient air to a desired state as the ambient air passes through the first dry channel. A heat exchanger characterized by:
16. 16. The heat exchanger system of claim 15, wherein the heat exchanger further comprises a second dry channel for pre-cooling the exhaust air before it enters through the wet channel.
17. An air conditioning system that conditions the air in a space, a heat exchanger having a first channel and a second channel, wherein a wall of the first channel and an adjacent wall of the second channel form a shared, thermally coupled wall; a dehumidifier operably connected to the second channel; a conditioned space operatively connected to the first channel; a first inlet adjacent a first end of the first channel and configured to draw conditioned air from the conditioned space; a first outlet adjacent a second end of the first channel and configured to discharge the conditioned air to the environment; a second inlet adjacent the first end of the second channel and configured to draw in ambient air from the environment; a second outlet adjacent a second end of the second channel and configured to deliver ambient air to the dehumidifier, the dehumidifier dehumidifying the ambient air into conditioned air before delivering the conditioned air to the conditioned space; and a liquid film disposed along a wall within the first channel, whereby as the conditioned air passes through the first channel, the conditioned air evaporates the liquid, lowering the temperature of the shared thermally coupled wall, and the second channel transfers heat through the thermally coupled wall to the first channel, lowering the temperature of the second channel, and pre-cooling the ambient air as it passes through the second channel.
18. an exhaust fan for drawing the conditioned air from the conditioned room into the first channel; 18. The air conditioning system of claim 17, further comprising a supply fan for drawing the ambient air into the second channel.
19. The heat exchanger includes a third channel that pre-cools the conditioned air after it leaves the conditioned room and before it enters the first channel.
19. The air conditioning system according to claim 18.