The invention relates to a method of conditioning air using a heat and mass exchange module comprising a plurality of air channels for air flow and a plurality of liquid channels, wherein a liquid channel is embodied as a layer of wicking material on a plate and is arranged adjacent to an air channel with a mutual exchange surface, which method comprises the steps of:
Providing flow of a liquid into the liquid channels, and
Providing air flow into the air channels.
The invention further relates to a heat and mass exchange module comprising a plurality of air channels for air flow and a plurality of liquid channels for flow of a liquid, wherein a liquid channel is embodied as a layer of wicking material on a plate and is arranged adjacent to an air channel with a mutual exchange surface, which liquid channel is provided with an entry and an exit and which air channel is provided with an inlet and an outlet.
A heat and mass exchange module of the above mentioned type—hereinafter also HMX module—comprises a plurality of parallel plates which are typically provided with at least one layer of wicking material. In operation, a liquid is applied onto the surface of the plates. In the context of air conditioning, the liquid may be a liquid desiccant or alternatively an evaporative liquid. Liquid desiccants are used for dehumidification, and are suitably aqueous salt solutions, typically hygroscopic and preferably concentrated. The liquid desiccants need to be regenerated after use. The HMX module can be used as a dehumidifier module and as a regenerator module. Evaporative liquid are used in evaporative coolers. These liquids may not be toxic, aggressive, corrosive and the liquid's heat of evaporation is suitably big so as to result in significant cooling of the air. The evaporative liquid is more particularly water, such as demineralised water or tap water, which further may include an additive. The HMX module may be used as a evaporative cooler.
If the HMX module is a dehumidifier module, the water concentration in the liquid desiccant is typically reduced before entry, so that the liquid desiccant can take up humidity from the air. Suitably, the liquid desiccant is also cooled. If the air-conditioner module is a regenerator or conditioner module, the liquid desiccant is suitably heated prior to entry, so as to facilitate evaporation of water from the liquid desiccant to the air. The HMX module may be further used as part of an air cooling (and/or heating) system. The term ‘HMX-module’ is used within the context of the present invention to refer to any module for use in a conditioning system for air and/or another gas. Where reference is made to an air-conditioner module, this is to be understood as synonym. The conditioning system may be arranged to condition humidity and/or temperature of the air. The conditioning system is typically used for air, such as available in offices, stables, houses, theatres, museums, sport halls, swimming pools and other buildings. The conditioning system may alternatively be used for conditioning an industrial gas flow.
A major problem for all these modules is carry-over. This is the undesired transfer of certain components present in the liquid into the air. Carry-over is undesired when using liquid desiccants, since the salts applied as liquid desiccant are typically corrosive. It is furthermore undesired that conditioned air would contain any droplets of salt. Carry-over is further undesired in evaporative coolers. At the temperatures at which evaporative coolers are applied, there is a risk that the water contains any micro-organisms such as bacteria. Carry-over of such bacteria into the air is undesired from the perspective of hygiene and safety.
One such liquid desiccant type air conditioner (also referred to as LDAC, or LDVPAC=liquid desiccant vapour compression air conditioning) module is known from WO2013/094206 (Sharp). This module uses plates comprising internal channels for refrigerant, so as to cool the plates. The use of such cooled plates provided with layers of wicking material (at the surface), such as a flocked surface of 0.5 mm Nylon fibers, allows operation with low desiccant flow rates of 0.5-1.01/m2/hour. As stated in [0023], such a flow rate is desired for wetting the defined region with such flocked surface. As mentioned in [0027], the smooth profile of the used roll-bond plate minimizes air stream turbulence, thus minimizing both the potential for desiccant carryover and the fan power demand, but in [0052] it is argued that there are various applications wherein carryover would not be critical.
WO2013/94206 thereafter mentions in [0061] that its module may be operated economically, notwithstanding to the thicker plates, according to various aspects of the invention, i.e. to use counterflow rather than crossflow, both for mass exchange and heat exchange; to increase turbulence (i.e. higher localized velocities), and to enable higher flow bulk air velocities without risking droplet carryover. For instance, the turbulence is increased by means of gaps and sharp edges thereto as shown in
However, the inventors of the present invention believe that turbulence likely results in carryover, which is to be avoided. Still it is desired to obtain a module that may be operated economically.
Another desiccant type air conditioner is known from US2012/0132513A1. The known apparatus may be operated in counter-flow or in cross-flow. It is based on hollow wavy plates that are constructed and assembled in such a way that the plates can thermally conduct heat. More particularly, the hollow plates are configured for flow of a refrigerant fluid inside them. The outside surfaces may be provided with a layer of a hydrophilic material, acting as a drain channel for liquid desiccant. Suitably a membrane is present on top of the drain channel. In use, there will thus be a predefined temperature difference between the thermally conductive plate and the air. Furthermore, humidity is driven from the air into the liquid, or out of the liquid into the air, resulting in liberating of condensation heat or withdrawal of evaporation heat.
In terms of flow dynamics, the situation of gas flow along a solid surface typically gives rise to a quasi viscous fluid layer at the interface with laminar flow, a buffer zone and a turbulent core of air. The behaviour in the buffer zone will be a mixture of turbulent and laminar flow; see f.i. R. B. Bird, W. E. Stewart & E. N. Lightfoot, Transport Phenomena (Wiley, page 375, FIG. 12-1.1, 18-5-1). In a situation of both mass transfer and heat transfer the temperature and velocity profile change in a non-linear manner, thus faster close to the interface with the liquid flow (FIGS. 21.5-1).
In other words, the turbulence in the buffer zone may extend towards the interface with the liquid flow. The corrugation in the layer of wicking material further reduces the threshold for generation of droplets from the liquid flow. US2012/0132513 does not address this risk of carry over altogether, except in the provision of a membrane on top of the hydrophilic layer of wicking material. This is furthermore confirmed in paragraph [0133], first sentence, which specifies the exchange between air and liquid desiccant through a membrane, as well as the heat transfer to a refrigerant as essential to the invention.
However, such an air conditioner is complex in a double sense: not only does it require a lot of different components, which typically increases manufacturing cost and reduces lifetime; furthermore, many parameters in the system needs to be controlled to arrive at a suitable operation. It is observed that US2012/0132513 does not contain any experimental data, so that the operation and particularly the air-conditioning behaviour remains rather speculative.
It is therefore an object of the invention to provide an improved method and an improved HMX module, which can be operated in an economically viable manner and does not have the risk of carryover of liquid desiccant into the air flow.
According to a first aspect, the invention provides an heat and mass exchange module comprising a plurality of air channels for air flow and a plurality of liquid channels for flow of a liquid, and wherein a liquid channel is arranged adjacent to an air channel with a mutual exchange surface, which liquid channel is provided with an entry and an exit and which air channel is provided with an inlet and an outlet, wherein
According to a second aspect, the invention provides a method of conditioning air using a heat and mass exchange module of the invention and controlling the air flow in a laminar flow regime.
It is the insight of the invention, that appropriate operation without carry-over is achieved by means of a design that is made for laminar air flow. Such a design is based on cross-flow of the liquid desiccant and the air. The cross-flow design is suitably implemented with a plurality of sheets, rather being based on plates, each of which comprises several sheets. In this manner, the density of air channels may be increased, and therewith the total exchange surface within a module of a given size. The sheets are stiffened by means of corrugations for obtaining sufficient stability. However, such corrugations are configured and arranged such that the air flow is not hindered so as to create local turbulence.
Particularly, the corrugations are designed such that the mutual exchange surface between an air channel and a liquid channel is substantially planar when following the first flow direction, and is non planar when following in the second flow direction. Thus, a first volume of a liquid flowing in the second flow direction will experience flow over a non-planar surface. However, a first volume of air flowing in the first flow direction will experience flow through a substantially straight channel. The terms ‘substantially planar’ and ‘substantially straight’ are used in the context of the present application in that the surface and the channel does not contain any interruptions or angles (for instance of 150 degrees or smaller, with fully straight defined as 180 degrees). It is not excluded that the substantially planar surface or substantially straight channel contains any slight curving, for instance leading to a deviation of less than 15 degrees, more preferably less than 10 or less than 5 degrees over the exchange surface. However, this is not preferred; a planar exchange surface when seen along the first flow direction, for instance allows that the edges of the sheet can be planar. This is deemed beneficial for the assembly of sheets and manifold and/or distance holders.
As the entire sheet is corrugated, a valley on one side corresponds to a ridge on an opposed side of the sheet. In one preferred embodiment, the sheet has a uniform thickness. This minimizes the volume within the module used by the sheets. However, this uniform thickness is not deemed necessary, and may be dependent on the manufacturing technique of the sheets. A sheet processed by thermoforming would typically have a substantially uniform thickness when the thermoforming starts from a planar sheet. A sheet processed by a moulding technique may easily have a varying width.
In a preferred embodiment, the corrugation has an amplitude that is at least 50% of the spacing between the sheets., and suitably at least 200%. More preferably, the amplitude is at least 80% of said spacing or even be in the range of 90-120%. Since the sheets are suitable identical in shape, such amplitude does not lead that the sheets would touch each other. For sake of clarity, it is observed that the spacing between the sheets is herein defined in the same direction as the amplitude of the sheet. Thus, suitably, a tip of a ridge of a first sheet extends substantially to or into a valley of an adjacent second sheet. In other words, the amplitude of the corrugation may be of substantially the same dimension as the spacing between the sheets.
Particularly preferred is an implementation wherein the corrugation is periodical, with a plurality of corrugations in the propagation direction of the liquid, for instance at least 6 periods per meter, or preferably at least 8 periods per meter or even at least 10 or 12 periods per meter. The periodic distance is for instance in the range of 1.0 to 15.0 cm, most preferably 1.0 to 5.0 cm. It has been found in experiments with sheets in the module of the invention, that good results were obtained with a pattern, wherein the ridges had a height which was smaller than the distance between neighbouring ribbons (as measured from heart-to heart, i.e. periodic distance). More preferably the height was at most half of the periodic distance, and more preferably at most one third. The distance between the plates is preferably at most 1.0 cm.
Such a corrugation has the advantage of providing an increase resistance against vibrations. Furthermore, the exchange surface area is increased significantly. Moreover, a single volume of air propagating in the air channel is side-wise substantially surrounded by liquid channel. Without corrugation or with limited corrugation, the liquid channel would be present merely sidewise, but not above or below this volume. Therewith, the distance to the sheet is reduced, which is beneficial to obtain sufficient heat and mass exchange in a laminar flow regime.
Suitably, the air flow is controlled in an air flow rate and the liquid flow is controlled in a liquid flow rate, and a mass flow ratio of the liquid flow rate over the air flow rate is at most 3.0, more preferably at most 2.5 or even at most 2.0. It has been found that such a mass flow ratio can be achieved with the module of the invention, and that is furthermore provided a very high drying efficiency of over 60% up to even over 90%, when the said mass flow ratio increases towards 2.0. However, good results have also been achieved with mass flow ratios in the range of 0.5 to 1.5.
In a preferred embodiment, the exchange surface between an air channel and a liquid channel is defined by a width of the liquid channel, rather than dimensions of the sheet. This width is understood to extend in the first flow direction and to be smaller than a distance between the inlet and the outlet of the air channel in the first flow direction. It is deemed preferable to define the exchange surface by means of the liquid channel, and thus particularly the arrangement of the entry, i.e. the entry points, of the liquid channel. This can be achieved in a rather precise manner.
Moreover, by limiting the width of the liquid channel, space is created outside the exchange surface for elements that may further stabilize the module, without having an impact on the flow and more particularly without creating a risk for carry over. More particularly, the air inlet and the air outlet may be configured to have a substantially rectangular cross-section. In fact, the non-planarity of the exchange surface when seen along the first flow direction corresponds to non-planarities along the width of the air channel.
In one suitable embodiment, an accommodation area is present between the inlet of the air channel and the exchange surface, when seen along the first flow direction. Such accommodation area is deemed beneficial to smoothen the air flow, and to provide a transition between a flow in a major pipe to flow through a plurality of air channels with limited height.
Preferably, the non-planarity of the exchange surface comprises a series of ridges and valleys. These ridges and valleys are suitably provided regularly. More particularly, the pattern of ridges and valleys along said direction suitably constitutes a wave shape, more particularly a sine wave shape.
In a preferred embodiment, the sheet further comprises at least one strengthening protrusion that is defined within an area extending substantially parallel to the liquid channel. Such strengthening protrusion is for instance arranged in the accommodation area and/or in an outlet area present between the exchange surface and the outlet of the air channel. Herewith stiffness of the sheet is further increased, therewith reducing the risk of carry over further. Such stiffness is for instance desired so as to prevent and/or suppress any vibrations that could otherwise influence the flow pattern in the air channel, and create larger carry-over from the liquid channel. The stiffness is further desired to counteract deformation of the sheets, which for instance may be due to expansion and/or contraction due to temperature differences, and more particularly differential thermal expansion between materials that are attached or bonded to each other. As a consequence of such deformation, the mutual distance between the sheets could decrease, so that droplets could bridge a first and a second liquid channel (actually separated by an air channel). Moreover, module manufacture is simplified by means of sheets of sufficient thickness. More preferably, the sheet comprises at least one strengthening portion in the accommodation area and at least one strengthening protrusion in the outlet area.
In a further embodiment, the width of the liquid channel is smaller than a length of the liquid channel. For instance, the width of the liquid channel is at most 85%, preferably at most 70%, or even at most 60% of the length of the liquid channel. The set up of this further embodiment increases the maximum exchange surface. It is based on tests demonstrating that the humidity in an air channel is already taken out of the air channel in its first portion, notwithstanding the fact that the laminar flow is less effective with respect to mass transfer than a turbulent flow. Preferably, in this respect, the width of the liquid channel is at least 10%, more preferably at least 20% of the length of the liquid channel.
In another embodiment, the HMX module further comprises a distance holder between a first and a second sheet. Preferably, the distance holder is arranged at the entry of the liquid channel, so that the exchange surface between air and liquid desiccant is uninterrupted. Additional distance holders—for sake of clarity hereinafter referred to as spacers—may be present at the exit of the liquid channel, at the inlet and/or at the outlet of the air channel. The use of a distance holder has the advantage that the distance between the sheets is fixed. This contributes to a defined cross-section of the air channel. Such a well-defined cross-section at least largely prevents variations in the height of the air channel, which otherwise could have an impact on the flow, i.e. a local narrowing typically enhances the flow rate, with a higher risk of turbulence and thus carry-over. The distance holders, arranged between adjacent sheets of the module, suitably have a strip-like extension. They are arranged between two adjacent sheets, but they face merely a portion of the sheets. In fact, where the distance holders are located, there is no mutual exchange surface between an air channel and a liquid channel. It is an arrangement of the distance holders at the top of the module, between the container and the liquid channels, is deemed beneficial.
More preferably, a plurality of air channels has substantially the same height. Therewith, it is achieved a single flow generating means, such as a pump and/or a fan, may be used for said plurality of air channels without creating differences in air flow, and hence unexpected patterns etc. It is of course feasible that air channels have a different height. The provision of a module with a first set of air channels with a first height and a second set of air channels with a second height different to the first height may be used to tune the amount of humidity that is transferred from the air channel to the liquid or vice versa.
In a preferred implementation, the distance holder at the entry of the liquid channel extending along the first flow direction between said first and second sheet is configured for defining entry regions and closed regions, which entry regions define entry point for the liquid desiccant into and onto the layer of wicking material, in which closed regions the distance holder extends from the first sheet to the second sheet. The use of such a distance holder has proven to enable an adequate transmission of liquid desiccant from a container thereof into the wicking material and a surface thereof, substantially without droplet formation or carry-over. In a further implementation, this distance holder is provided, when in use, with an interface with the layer of wicking material on the sheet. The distance holder is configured and arranged such that the layer of wicking material is compressed locally, therewith forming a closed region.
In a more particular implementation of the distance holder, it is provided with a surface of hydrophobic material. It suitably has a bottom surface that is exposed to at least one air channel, which bottom surface has a concave shape between lower edges adjacent to the first and the second sheet and an upper region between said edges. Both these implementation measures contribute to reducing the risk of carryover. In fact, with this choice of material and this shape of the bottom surface of the distance holder, a barrier is provided against flow of liquid desiccant along the surface and against the formation of droplets anywhere at the bottom surface that would otherwise drop down into the underlying air channel.
Preferably, the HMX module is designed, such that an air channel is present between a first and a second liquid channel of liquid desiccant, which liquid channels are defined by means of layers of wicking material on adjacent sheets. The number of sheets is suitably at least 10 preferably at least 30, more preferably at least 50, so as to arrive at a suitable surface area for exchange between the air channels and the liquid channels. However, this number may be changed, in dependence of climate, air volume to be conditioned, operation time, surface area of a single sheet, and other factors, such as available space. The individual sheets are preferably of uniform thickness. Suitably, the sheets are laminates of a carrier and one, preferably two layers of wicking material, more particularly a textile material. Hence, they do not contain any channels for refrigerant.
In again a further embodiment, the surface area of the exchange surface per unit volume (exchange surface area′) is at least 300 m2/m3. This high density of exchange surface area is achieved in the invention on the basis of the well defined sheets, allowing that the height of the air channel is relatively small, for instance lower than 0.6 cm or even 0.4 cm or lower. Furthermore, due to the use of corrugated sheets without internal cooling, the thickness of an individual sheet is limited. Typically, in modules based on plates with internal cooling, the exchange surface area is in the order of 100 m2/m3. This is far below the exchange surface area in the invention of at least 300 m2/m3, preferably even at least 400 m2/m3. In preliminary designs, an exchange surface area of close to 450 m2/m3 was obtained. Improvements in the design to values above 500 m2/m3 are deemed realistic. The high density of exchange surface area not merely is an attractive alternative to a module based on cooled plates, but also provides an excellent distribution of heat. On the basis thereof, and by variation of the input temperature of the liquid desiccant, particularly LiCl, it is feasible to operate the module under conditions wherein the air will not heat up during the dehumidification step. By using a liquid desiccant at low temperature, for instance below 20° C., or even in the range of 10-15° C., or more generally of at least 8 degrees, preferably at least 10 degrees below room temperature, the air may even be cooled due to the convection.
These and other aspects of the air-conditioner module and the method of air conditioning are further elucidated with reference to following figures, which are not drawn to scale and are merely diagrammatical in nature. Equal reference numerals in different figures refer to identical or corresponding elements. Herein:
In this manner, the liquid desiccant will flow within the HMX module 100 under the impact of gravity. The module as shown in
The HMX module as shown in
In a further implementation, an air conditioning system may contain an evaporative cooler module and a dehumidifier module. These modules are preferably arranged such the evaporative cooler module is located upstream to the dehumidifier module, with respect to the air flow. This is deemed a most effective combination, since the evaporation may result in cooler, more humid air. Subsequent drying of this air is more efficient than drying of warmer, less humid air. Thereto, it is deemed beneficial that a first air flow is transported from the evaporative cooler module to the dehumidifier module without intermediate mixing with any conditioned air. However, it is not excluded that any mixing of the first air flow with a second air flow occurs before the dehumidification. This may for instance beneficial if the capacity of the dehumidifier module is larger than that of the evaporative cooler module, and/or if a bypass around the evaporative cooler module is available for reasons of tuning. Rather than a direct evaporative cooler, the dehumidifier module of the invention may be combined with an indirect evaporative cooler and/or any other heat exchanger. In an indirect evaporative cooler, cooled fluid from the evaporative cooler is transported into a heat exchanger with the air flow. It will be understood that such air conditioning system with an evaporative cooler module in series with a dehumidifier module will further comprise a regenerator module for regeneration of liquid desiccant after exchange with the air—both being integrated into a circuit with any further heat exchanger as known per se to the skilled person. It will further be understood that the air conditioning system suitably comprises a controller for controlling the operation of the modules and for conditioning of the air in accordance with a predefined programme and/or user-specified settings.
As shown in
In one implementation according to the invention—not shown—the height of a ridge and a valley is higher in the middle part of the air channel than close to the outlet area 24. Herewith, it may be prevented that carry-over occurs at the end of the air channel due to a sudden change in direction of the air channel. In one further or additional implementation according to the invention, the ridges and valleys extend from the active area 25 into the outlet area 24. Therewith, it is achieved that the end of said ridges and valleys, corresponding to a change in orientation of the air channel is at least substantially outside the exchange surface between air and liquid desiccant material.
In again one further implementation, the height of ridges and valleys may be lower in a bottom part of the air channel than in a top part. The liquid desiccant may gain velocity in the course of flowing downwards. In a dehumidifier module, it additionally may warm up. Therefore, the lower part is more sensitive to carry over. This may be compensated by less steep ridges and valleys, to prevent any ejection of single droplets of liquid desiccant.
In the shown embodiment, the ridges 12 and valleys 13 extend parallel to the width of the liquid channel 30, such that the liquid channel 30 in fact includes a curved trajectory. However, the air channel 20 is substantially planar over the width of the liquid channel, i.e. in the area where the liquid channel and the air channel have an interface. This has the advantage of minimum disturbance of air flow. As a consequence, carry over can be prevented, at least substantially, while the sheets are very thin. In this manner, a large packing density of sheets per unit volume is achieved, resulting in a large exchange area between the air channels and the liquid channels. In tests with a preliminary version of the heat and mass exchange module according to the invention, wherein the air flow was laminar and a liquid channel wave-shaped, no carry-over was found to occur. The sheet 10 is suitably created in a multistep process. In a first process, layers of wicking material are added to a carrier. The carrier is suitably an engineering plastic, such as PET, polycarbonate, high-density polyethylene and polypropylene. Good results have been achieved with materials have high temperature resistance, such as polypropylene or high-density polyethylene, with polypropylene being particularly preferred. For dehumidifier modules that are not subjected to operation at high temperature for a long duration, other carrier materials are very suitable as well. The wicking material typically comprises a fibrous material, such as a textile material, for instance cotton, linen, rayon or nylon fibres. Alternative hydrophilic, fibrous materials, such as starch and particularly treated starches, are not excluded. Natural rather than synthetic fibres are deemed preferred as a basis for the wicking material, since they are chemically inert and stable to LiCl and other saline desiccants. Rayon, and particularly viscose, is deemed a particularly preferred choice. Rather than a single material, a blend of materials may be applied, for instance a blend of a viscose with a carrier material, for instance an engineering plastic, such as polyethylene terephthalate, polyethylene, polypropylene, polyvinylchloride, polyester. A blend with up to 50 wt % carrier material, for instance 25-40 wt % carrier material is deemed very suitable. Preferably, use is made of a non-woven material that appears to be beneficial for the further step of the process. Most preferably, the non-woven material is a spunlaced material. The addition process may be achieved either by dipping (passing of a bath), coating, or laminating. The laminating process is preferred. The carrier may have been pre-treated to improve adhesion, for instance by means of a surface treatment (such as a plasma treatment), or in the provision of an adhesion promoter or even a glue layer. In one advantageous embodiment, use is made of lamination under pressure, wherein an interlayer is formed between the carrier and the layer of wicking material. Good results have been obtained therewith. An advantage of this joining technique is that there is no glue needed, which could be sensitive to dissolution under the impact of the liquid desiccant that is typically very salty and corrosive. The glue may further have an impact on the porosity of the wicking material, and therewith on its wicking properties. In a further process step, the combined material is then thermoformed so as to create the corrugation of the surface, more particularly the ridges, valleys and any protrusions. Herein, the use of non-woven material is deemed beneficial, as it provides less resistance against the concomitant extension than any woven material. The thermoforming step was carried out in a manner so as to obtain an increase in surface area (stretch′) of 10-25%. It was found that this stretch could be made without any delamination occurring between the carrier and the layer of wicking material. The thermoformed sheet moreover turned out stable up to at least 100° C., or even up to 120° C. The thermoforming step may alternatively be carried out simultaneously with the laminating step.
Additionally,
One further advantage of the design shown in
The configuration of
The
The operation of this strip for the distribution of liquid desiccant is more specifically and still schematically shown in
In the
As shown in
In contrast to the prior art, the dependence between the pressure drop and the air flow rate in the module according to the invention is linear. This implies that the flow regimen in the module is laminar flow. It makes that the air flow can be increased to commercially viable values without increasing the risk of carryover. Experiments were made with the module of the invention to detect the occurrence of carry-over. It was observed that carry-over occurred only at flow rates of approximately 4500 m3/h and higher. The striped area shown in
The module may further be provided with a plurality of containers below an exit of the liquid channels 30, i.e. at the bottom of a module 10, so as to collect the liquid that has passed the liquid channels in a specific section separately. Typically, such section corresponds to the overlying containers 71-73, and any connections to the entry regions of the liquid channels. It has been found, in experiments with a first prototype of the module of the invention, that the liquid flows downwards without broadening of flow area.
In operation, the first, second and third containers 71-73 are typically provided with liquid that will flow into the liquid channels 30 of the module 10 from the containers 71-73. Suitably, the containers 71-73 are arranged such that each of them overlies a section of substantially all the liquid channels 30. More preferably, the intermediate manifold—which is particularly embodied in the form of stripwise extending distance holders as shown in
The use of a plurality of containers 71-73 in combination with a single module 10 may be used for setting a flow profile along the width of the liquid channel 30. This is deemed beneficial to tune and optimize the flow.
The use of a plurality of containers 71-73 in combination with a single module 10 may further be used so that different liquids will flow in different sections of the liquid channels 30. In one specific example, the liquid flowing from the first container 71 into the first section is an evaporative liquid, such as water, and the liquid flowing from the third container 73 into the third section is a liquid desiccant. The second container 72 is for instance kept empty. The functions of evaporative cooler and dehumidifier are therewith integrated into a single module. This significantly simplifies the overall design, since there is no need for any connection of modules. Still, the air flow is first cooled and thereafter dehumidified.
In another specific example, the first container 71 contains an evaporative liquid, particularly water, the second container 72 contains a liquid desiccant and the third container 73 contains a diluted solution of any desired additive, for instance a disinfectant, a fragrance or parfum. It will be understood that variations are feasible. A single module may contain merely two overlying containers or even more overlying containers. Furthermore, it may be feasible that the two of the containers contain the same liquid (water, liquid desiccant), but in a different state, so as to set a flow profile along the width of the liquid channel. Options for setting flow profiles are further specified in a co-pending and simultaneously filed application of the Applicant. Generally, the term ‘state’ of the liquid refers to temperature, (static) pressure, concentration and/or composition.
Furthermore collecting containers 91, 92 are shown for the two different liquids.
It will be understood that the subdivision into a first 30A and a second section 30B only is merely an example and that any desired number of sections may be present. Furthermore, in dependence of the overall width of the sheets, a further strengthening protrusion may be defined in the intermediate isolation area 33. Rather than implementing the first section 30A and the second section 30B onto a single sheet 10 by patterning the layer of wicking material 11, it is feasible that the first section 30A and the second section 30B are defined on separate sheets that are however integrated into a single module. Furthermore, though it is deemed beneficial for manufacturing reasons and for the avoidance of carry-over that the corrugation present in the first section 30A and the second section 30B is identical, this is not deemed strictly necessary.
Furthermore, air is transmitted between its inlet 21 and its outlet 22. This air channel is effectively rather straight, at least for an infinitesimally small volume of air, and more particularly within the width of the liquid channel. The sheet may further be strengthened by means of additional protrusions running in a direction different and preferably substantially perpendicular to the series of waves. Preferably, these protrusions are themselves also wave-shaped and more preferably, they are located outside the liquid channel. The manifold 40 is herein most suitably embodied as a plurality of strips that simultaneously act as spacer between adjacent sheets. As shown in
What matters, is that the first inlet 61 is designed for another type of liquid than the second inlet 62. In one most beneficial example, the first inlet 61 is configured for water and the second inlet 62 is configured for the provision of a cleaning disinfectant. The intention thereof is that the cleaning disinfectant will flow over a broader area than the water.
This principle is shown in
However, after a predefined time of operation, the module needs cleaning. This cleaning more particularly involves a disinfectant so as to remove any type of microbiological material. However, the cleaning may alternatively or additionally include a treatment with another type of solution. In accordance with this embodiment and as shown in
It is added for sake of completeness that an aqueous solution could be applied as an alternative to water. Such aqueous solution is typically diluted, particularly in comparison to a liquid desiccant solution and suitably diluted to such an extent that a layman would consider the resulting liquid any kind of water.
This innovative design as shown in
Number | Date | Country | Kind |
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2013563 | Oct 2014 | NL | national |
2013989 | Dec 2014 | NL | national |
This application is a 371 national stage application of PCT Patent Application No. PCT/NL2015/050683, entitled “A method of conditioning air and an air-conditioner module,” filed on Sep. 30, 2015, which claims priority to Dutch Patent Application No. 2013563 filed on Oct. 2, 2014 and Dutch Patent Application No. 2013989 filed on Dec. 16, 2014, the entire contents of which are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/NL2015/050683 | 9/30/2015 | WO | 00 |