WATER SUPPLY SYSTEM AND METHOD OF SUPPLYING WATER

Abstract

 The present invention provides a water supply system and a method of supplying water, the system comprises: a wick holding chamber, holding a wick therein, the wick being arranged for absorbing and containing water flew thereon to evaporate; a water tank, storing the water therein, the water tank being physically separated from the wick; a water transporting means, connected to the wick holding chamber and the water tank respectively for transporting the water from the water tank to the wick during the humidification period and the prior preparation period thereof; and a control unit, connected to the water transporting means, the control unit being configured to control the flow rate of the water transportation from the water tank to the wick. It enables an effective disinfection of the entire wick of an evaporative humidifier without using UVC lamp, and the humidification performance can be substantially improved meanwhile.

Description

FIELD OF THE INVENTION

[0001] The invention relates to the technical field of humidification, and in particular it relates to a water supply system and a method of supplying water applied in a humidifier or a 2-in-1 air purifier and humidifier.

BACKGROUND OF THE INVENTION

[0002] Humidifiers are available from many brands and widely used to increase the humidity level of air in indoor spaces. Philips has several such products in the current portfolio. Different architectures have been developed based on different principles (evaporative humidifiers, vaporizers, impeller humidifiers, ultra-sonic humidifiers etc.), but they usually have one thing in common: a water tank which represents a reservoir for the water needed during operation.

[0003] Humidifiers based on cold evaporation typically make use of a wick which is located within the air flow path of the appliance in such a way that a portion of the wick is always submerged by water inside the water tank. This allows the non-submerged wick portion to always remain wet. During operation, a fan blows air through the moist wick and as water evaporates during this process, new water is continuously sucked into the wick by capillary forces.

[0004] Growth of microorganisms typically occurs over time in such devices due to the availability of water. The wick represents the structure with the largest surface area within the water tank which can be potentially colonized by microbes. This has not only negative impact on user experience due to the occurrence of malodor, but can also lead to heath issues, namely when microorganisms and/or their by-products such as MVOCs are released into the air. This is relevant for the general population, but of particular importance for asthmatic and allergic persons since fungi, mold and other microbe-derived substances such as endotoxins can act as asthma triggers, irritants and the like.

[0005] Microbial growth is largely dependent on the presence of water. Without water, microbes such as bacteria and fungi quickly dry out which typically leads to an instant stop of metabolic activity (resulting in growth and replication stop) and subsequently to a rapid loss in viability in many species. The process of removing moisture from a body of an organism is also known as desiccation. "For example, Treponema pallidum, the agent of syphillis, is so intolerant to water loss that it will die within twenty seconds on the surface of a dry fomite. The physical preservation of foodstuffs by drying has been practiced by humans for thousands of years and in most cases does reduce the number of potentially pathogenic microbes (http://academic.pgcc.edu/∼kroberts/web/recit/rec12.htm)."

[0006] As indicated above, one major problem with humidifiers is microbial growth on the wick. In order to solve this problem, some manufacturers such as Dyson implemented UVC light sources into their devices. The problem of such an approach is that the microorganisms need to be actually exposed to the UVC radiation; microorganisms located in shaded areas/surfaces won't be inactivated. If one takes a photograph of the UVC illuminated water compartment of a Dyson humidifier, several shaded areas can be seen.

[0007] In wick-based humidifiers, the wick itself represents a light-absorbing structure. If a light source such as and UVC lamp is implemented into a wick-containing water tank, the wick will cause shadows, hence areas where the dose of light is insufficient to cause effective inactivation of microbes.

SUMMARY OF THE INVENTION

[0008] The present invention intends to solve the problem of microbial growth on the wick and inside the water tray of an humidifier by providing a water supply system and a method of supplying water to enable an effective disinfection of the entire wick and even the water tank of an evaporative humidifier without using UVC lamp or the like, while improving the humidification performance at the same time.

[0009] In order to solve the above mentioned technical problem(s), the present invention proposes to provide a water supply system for an evaporative humidifier, comprising:

a wick holding chamber, holding a wick therein, the wick being arranged for absorbing and containing water flew thereon to evaporate;

a water tank, storing the water therein for humidification, the water tank being physically separated from the wick;

a water transporting means, connected to the wick holding chamber and the water tank respectively for transporting the water from the water tank to the wick in the wick holding chamber during the humidification period and the prior preparation period thereof; and

a control unit, connected to the water transporting means, the control unit being configured to control the flow rate of the water transportation from the water tank to the wick.

[0010] In one embodiment of the present invention, optionally, the water transporting means comprises a water driving means, a water tubing and one or multiple water outlet nozzles; the water driving means obtains the water in the water tank and drives the water by virtue of the water tubing to the wick holding chamber, the water is discharged onto the wick via the water outlet nozzles connected to the water tubing.

[0011] In one embodiment of the present invention, optionally, the control unit is connected to the water driving means; the control unit is configured to regulate the water driving means in such a way that at least two different water flow rates are applied, one initial water flow rate for the preparation period and another one sustaining water flow rate for the subsequent actual humidification period; the initial water flow rate is equal or greater than the sustaining water flow rate.

[0012] In one embodiment of the present invention, optionally, the control unit is configured to regulate the water driving means in such a way that once the wick is fully moistened during the preparation period, switching the initial water flow rate to the sustaining water flow rate for keeping the water amount on the wick constant during the humidification period.

[0013] In one embodiment of the present invention, optionally, the state of fully moistened is defined by an algorithm inside the control unit which powers the water driving means at the initial water flow rate for a predefined time period, whereby this time period is derived from the water uptake capacity of the dry wick and the value of the initial water flow rate.

[0014] In one embodiment of the present invention, optionally, the humidifier comprises an air flow generating means, coupled to the wick for generating an air flow through and/or along the wick with water vapor to carry away therefrom;
the air flow generating means comprises a fan, the fan sucks air outside the wick holding chamber to go through an air inlet into the wick holding chamber and sucks/blows the air through and/or along the wick, so that moist air is released from the wick holding chamber via an air outlet to produce humidification.

[0015] In one embodiment of the present invention, optionally, the control unit is further connected to the air flow generating means, the control unit is further configured to control the air flow generating means to continue to generate the air flow through and/or along the wick for drying while stopping the water transportation to the wick once the humidifier is instructed to be switched off until the wick becomes acceptably dry.

[0016] In one embodiment of the present invention, optionally, the acceptably dry refers to a dry status that the wick contains no greater than 5% of water.

[0017] In order to solve the above mentioned technical problem(s), the present invention further proposes to provide a method of supplying water using the water supply system for an evaporative humidifier of any of the above mentioned embodiments of water supply system, comprising:

receiving an instruction indicative of switching on the humidifier;

activating the water transporting means and transporting the water stored in the water tank to the wick in the wick holding chamber during the humidification period and the prior preparation period thereof;

wherein the flow rate of the water transportation from the water tank to the wick is controlled in view of including different working phases, at least two different water flow rates are applied, one initial water flow rate for the preparation period and another one sustaining water flow rate for the subsequent actual humidification period; the initial water flow rate is equal or greater than the sustaining water flow rate.

[0018] In one embodiment of the present invention, optionally, the initial water flow rate corresponds to the water uptake dynamics of the dry wick; and/or the sustaining water flow rate corresponds to the water loss rate of the wick due to water evaporation.

[0019] In one embodiment of the present invention, optionally, the sustaining water flow rate is a function of ambient temperature and ambient relative humidity and optionally further taking into account the air flow rate/fan speed through and/or along the wick.

[0020] In one embodiment of the present invention, optionally, the water supply rate to the wick is controlled to decrease as the ambient relative humidity increases as a result of the humidifier operation, so that the F ratio continuously decreases from 1; wherein the F ratio is defined as follow:

wherein,

e refers to the total water evaporation rate indicative of the total amount of water which evaporates per unit time from the wick at a specific ambient temperature and relative humidity, in ml/min;

f refers to the water supply rate towards the wick by the water transporting means, in ml/min;

wherein the F ratio is being continuously decreased and approaches zero as the relative humidity approaches a threshold humidity level set by user.

[0021] In one embodiment of the present invention, optionally, the ambient temperature and the ambient relative humidity are derived from integrated sensors equipped on the humidifier or from external reference sources connected with the humidifier.

[0022] In order to solve the above mentioned technical problem(s), the present invention still further proposes to provide a computer readable storage medium having computer readable program instructions embodied therewith for, when executed on a control unit, causing the control unit to implement any of the above mentioned embodiments of methods of supplying water.

[0023] In order to solve the above mentioned technical problem(s), the present invention still further proposes to provide a computer program product comprising a computer readable storage medium having computer readable program instructions embodied therewith for, when executed on a control unit, causing the control unit to implement any of the above mentioned embodiments of methods of supplying water.

[0024] As compared with the prior arts, the present invention has the following technical benefits and characteristics:
The present invention provides a system and a method of supplying water which can be applied on wick-based humidifier having separate compartments for the water tank and the wick. More specifically, the information about current and target ambient RH, temperature and fan setting of the humidifier can be used to control the flow rate of water to the wick.

[0025] The present invention is able to substantially reduce the microbial growth within an e.g. wick-based evaporative humidifier. In general, it's realized by applying water to the wick during usage only and making sure that the wick is dry in between usage. Hence, the inhibition of microbial growth can be achieved by: a) minimizing the time where microbial growth can actually occur on the wick; and b) inactivating microbes after each usage by desiccation.

[0026] When applied to a humidifier, inhibiting microbial growth will reduce risk of exposure to pathogens, maintenance frequency and smell nuisance.

[0027] Moreover, in contrast to current humidifiers, where the wick is located inside the actual water tank and therefore at least partially submerged by water, the present invention makes it possible that the entire wick surfaces is available for water evaporation as no portion of the wick is actually submerged in the water tank anymore, which results in higher humidification rates (hence better humidification performance) at same size of the wick or smaller wicks (hence smaller humidifier appliances) at same humidification rates.

[0028] At last, in the light of the present invention, a simple geometry of the water tank can be easily realized without any shade-causing structures and a simple UVC light source or the like be used to achieve homogenous irradiation of the entire water tank volume and its surfaces, and then an evaporative humidifier with simple architecture can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

Fig. 1 schematically shows the cross-sectional view of a water supply system for an evaporative humidifier according to one embodiment of the present invention;

Fig. 2 shows a psychrometric chart illustrating that the humidification rate, represented by the vector AB, depends on the position of point A and therefore on the temperature and absolute humidity, for an evaporative humidifier;

Fig. 3 shows another psychrometric chart further illustrating that compensation for humidification rate in an evaporative humidifier can be achieved by considering the ratio CD/AB; and

Fig. 4 schematically shows the value interrelationship for F ratio and ambient relative humidity for an evaporative humidifier controlled under a water supply method according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] Fig. 1 schematically shows the cross-sectional view of a water supply system for an evaporative humidifier according to one embodiment of the present invention. Please refer to Fig. 1, the main components of the disclosed water supply system 200 include a wick holding chamber 202a, a water tank 202b, a water transporting means 210 and a control unit 212. The wick holding chamber 202a holds a wick 204 therein, the wick 204 is arranged for absorbing and containing water flew thereon to evaporate. The water tank 202b stores the water therein for humidification, and the water tank 202b is physically separated from the wick 204. The water transporting means 210 connects to the wick holding chamber 202a and the water tank 202b respectively for transporting the water from the water tank 202b to the wick 204 in the wick holding chamber 202a during the humidification period and the prior preparation period thereof. The control unit 212 connects to the water transporting means 210, and the control unit 212 is configured to control the flow rate of the water transportation from the water tank 202b to the wick 204.

[0031] Specifically speaking, the water transporting means 210 mainly comprises a water driving means 207 (e.g. water pump), a water tubing 208 and one or multiple water outlet nozzles 209. The water driving means 207 obtains the water from the water tank 202b and drives the water by virtue of the water tubing 208 to the wick holding chamber 202a, the water is discharged onto the wick 204 via the water outlet nozzles 209 connected to the water tubing 208.

[0032] Specifically speaking, the control unit 212 is connected to the water driving means 207 and configured to regulate the water driving means 207 in such a way that at least two different water flow rates f_i, f_s are applied, one initial water flow rate f_i for the preparation period and another one sustaining water flow rate f_s for the subsequent actual humidification period. The initial water flow rate f_i is equal or greater than the sustaining water flow rate f_s.

[0033] More specifically speaking, the control unit 212 can be configured to regulate the water driving means 207 in such a way that once the wick 204 is fully moistened during the preparation period, the initial water flow rate f_i is changed to the sustaining water flow rate f_s for keeping the wick 204 exactly moist during the humidification period. Alternatively, in order to achieve two different water flow rates f_i, f_s, the control unit 212 can also be configured to control other component(s) of the water transporting means 210, such as the diameter of the water outlet nozzle(s) 209, for providing at least two different water flow rates.

[0034] In the embodiment of the present invention, the state of "fully moistened" is achieved by an algorithm inside the control unit 212 which powers the water driving means 207 at the initial water flow rate f_i for a predefined time period, wherein this time period is derived from the water uptake capacity of the dry wick 204 and the value of the initial water flow rate f_i.

[0035] In one embodiment of the present invention, the evaporative humidifier may comprise an air flow generating means 205 which can be coupled to the wick 204 for generating an air flow 211 through and/or along the wick 204 with water vapor to carry away therefrom. The air flow generating means 205 may comprise a fan, the fan sucks air outside the wick holding chamber 202a to go through an air inlet 203 into the wick holding chamber 202a and sucks/blows the air through and/or along the wick 204, so that moist air is released from the wick holding chamber 202a via an air outlet 206 to produce humidification.

[0036] The control unit 212 can be further connected to the air flow generating means 205 and further configured to control the air flow generating means 205 to continue to generate the air flow 211 through and/or along the wick 204 for drying while stopping the water transportation to the wick 204 once the humidifier is instructed to be switched off until the wick 204 becomes acceptably dry. The aforementioned "acceptably dry" may refer to a dry status that the wick 204 contains no greater than 5% of water.

[0037] Therefore, in contrast to current wick-based evaporative humidifiers, the water tank 202b of the present invention is physically separated from the wick 204 so that there is no direct contact between the water inside the water tank 202b and the wick 204. The water is applied to the wick 204 during the actual humidification cycle only. One important aspect of this invention can be the control algorithm in the control unit 212 to ensure that:

a) the water flowed towards the wick 204 directly after the device has been switched on is high enough to ensure that the maximum humidification performance is quickly reached;

b) the water supplied to the wick 204 during the steady-state phase (sustaining phase) exactly compensates the water loss due to evaporation; and

c) the wick 204 is acceptably dried before the device is wholly powered off after each humidification cycle.

[0038] The following parts describe in more detail how the present invention can be implemented and how it should be used to achieve ideal inhibition of microbial growth as well as optimal humidification performance.

[0039] Please still refer to Fig. 1, the air flow generating means 205 (e.g. fan) sucks air from the outside of a housing 201 into the humidifier device via the air inlet 203, where it passes the wick 204 and is blown out of the device via the air outlet 206. In contrast to current evaporative humidifiers, where the wick is located inside the water tank, the housing 201 contains at least two compartments in the base portion of the humidifier: a wick holding chamber 202a and a water tank 202b. This separation of the water tank 202b and the wick 204 makes it possible to keep the wick 204 acceptably dry whenever the humidifier is not put into use.

[0040] Once the humidifier is powered on, the water driving means 207 (e.g. water pump) is activated and drives water from the water tank 202b via the water tubing 208 to the water outlet nozzle(s) 209 where it is discharged onto the wick 204, such as the upper portion or upper surface of the wick 204 or the side face of the wick 204 is moistened. Subsequently, the water travels throughout the wick 204 driven by gravity and/or capillary forces. So the capillary forces together with a contribution of gravity ensure that the water is evenly distributed throughout the entire wick 204. Now, as air flows through the wick 204, evaporation takes place so that the water content of the air leaving the wick 204 and the device via the air outlet 206 is substantially higher than when entering into the device via the air inlet 203.

[0041] In one preferred embodiment of the present invention, let's suppose the water uptake capacity of the dry wick 204 is 50 ml and the initial water flow rate f_i is 100 ml/min. The sustaining water flow rate f_s is set to optimally match the humidification rate/water loss rate (equals to the evaporation over the entire wick 204 at a certain ambient temperature and relative humidity (RH)) of the humidifier. For instance, in a situation where the humidification rate is 600ml/hour, the sustaining water flow rate f_s is around 10ml/min.

[0042] Hence, once the humidifier of this embodiment is turned on, it takes 30 seconds (preparation period) until the entire wick 204 is fully moistened and the maximum humidification rate can be reached. Therefore, the control unit 212 is configured to set the water driving means 207 to initial water flow rate f_i = 100ml/min for the first 30 seconds (preparation period) after the device has been powered on. After the entire wick 204 has become soaked, the control unit 212 then switches to set the water driving means 207 to sustaining water flow rate f_s = 10ml/min which ensures that just the right amount of water is supplied to the wick 204 during the humidification period for keeping the wick 204 exactly moist.

[0043] Furthermore, in one preferred embodiment, the device also contains a control mechanisms which stops the water supply to the wick 204 as soon as a user switches off the device, but maintains the fan-mediated air flow for a defined period of time, the period of time being sufficiently long to allow the wick 204 to acceptably dry.

[0044] In reality, the evaporation rate of the humidifier will depend on: 1) the humidity of the ambient air, 2) its ambient temperature as well as 3) the air flow rate through the device. Therefore, a fixed sustaining flow f_s will most often lead to either an insufficient water supply to the wick 204 which will continuously reduce the humidification performance until the wick 204 is dry or an excessive water supply which will cause water accumulation in the wick holding chamber 202a. Therefore, a more sophisticated embodiment takes these 3 factors (ambient temperature, RH and air flow/fan setting) into account and adjusts the sustaining water flow rate f_s in such a way that the amount of water supplied to the wick 204 always corresponds to the actual humidification rate. In general, evaporation rates increase with increasing ambient temperature and/or decreasing relative humidity and/or increasing air flow rate/fan speed, and then the sustaining water flow rate f_s is increased by the system correspondingly.

[0045] In addition, the present invention also discloses a method of supplying water using the water supply system shown in Fig. 1 according to any of the above mentioned embodiments of the present invention. Specifically speaking, the method may comprise the following steps:

receiving an instruction indicative of switching on the humidifier;

activating the water transporting means 210 and transporting the water stored in the water tank 202b to the wick 204 in the wick holding chamber 202a during the humidification period and the prior preparation period thereof;

wherein the flow rate of the water transportation from the water tank 202b to the wick 204 is controlled in view of including different working phases, at least two different water flow rates f_i, f_s are applied, one initial water flow rate f_i for the preparation period and another one sustaining water flow rate f_s for the subsequent actual humidification period; the initial water flow rate f_i is equal or greater than the sustaining water flow rate f_s.

[0046] In one embodiment of the present invention, the initial water flow rate f_i is determined by the water uptake capacity of the dry wick 204 and the time the system operates at the initial water flow rate f_i , the sustaining water flow rate f_s corresponds to the water loss rate of the wick 204 due to water evaporation (humidification rate).

[0047] It can be understood that the disclosed method of supplying water can use information about the ambient temperature and relative humidity (e.g. from integrated sensors equipped on the humidifier or, in case the humidifier is connected, from external sensors or reference sources) and the air flow rate/fan speed to derive the current humidification rate, hence the required water supply rate to the wick, as explained in the following. That is to say, the sustaining water flow rate f_s can be a function of ambient temperature and ambient relative humidity (RH) and optionally also taking the air flow rate/fan speed through and/or along the wick 204 into account.

[0048] Fig. 2 shows a psychrometric chart illustrating that the humidification rate of an evaporative humidifier depends on ambient humidity and temperature. Please see Fig. 2, normally the humidification rate of the appliance in highest speed setting is established in standard conditions represented by point A in Fig. 2. The graph is a standard psychrometric chart where the X-axis is temperature and the Y axis is absolute humidity. The potential for evaporation is defined by magnitude of vector AB where point B represents the saturated condition of the air.

[0049] Therefore, in the above-illustrated Fig. 2, the humidification rate in condition A is reflected by the length of AB. As the relative humidity increases, the condition point moves closer to point B and the length of AB decreases. The drop in length of AB reflects the drop in humidification rate achievable in the higher ambient relative humidity.

[0050] Fig. 3 schematically shows another psychrometric chart further illustrating that the time to evaporate a specific volume of water inversely correlates with the length of the vector AB or CD. The longer the vector, the shorter the time required to evaporate a defined amount of water. This relationship can be used to optimally adjust sustaining water flow rate f_s based on ambient relative humidity and temperature and to determine the time required to dry the wick, at different ambient humidity levels and temperatures.

[0051] For instance, if the humidifier is being operated in condition represented by point C instead of those represented by point A in the graph, the potential for evaporation is given by the magnitude of vector CD. In this case, the evaporation rate will be higher by the ratio CD/AB than the previous circumstance.

[0052] In particular, as for Fig. 3, the potential for evaporation in condition A is depending on the length of AB. The potential for evaporation in condition C is depending on the length of CD. Points B and D respectively represent the saturated conditions of the air at different saturation temperatures. Thus, in order to compensate from condition C to condition A, the water supply rate as determined for standard conditions should be multiplied by AB/CD (the length of AB divided by the length of CD).

[0053] This may be expressed as a ratio of temperatures (T-Tw)/(20-10.8), because in this case the standard dry bulb temperature for deriving the humidification rate is 20°C at relative humidity 30% RH. This gives a corresponding wet bulb temperature of 10.8°C. Tw for different temperatures and humidity's can be provided in a look-up table in the software or a simple transfer function may be used.

[0054] Alternatively, the calculation can be done as a ratio of absolute humidity.

[0055] Likewise, the humidification rate can also be a function of fan speed. The humidification rate at speeds other than the maximum speed is simply a ratio that can be stored in the firmware of the machine and applied to the calculation.

[0056] In some embodiments, the time the fan continues operating after the user switches off the device is also determined by the system based on these three factors. Higher relative humidity and lower temperature will require a longer fan operation time after the water supply has been turned off. The fan speed can also be increased to accelerate the drying process.

[0057] Since microbial growth can't take place without water (dry), the problem of microbial growth on the wick can be solved without the need of extra physical disinfection means or impregnation of the wick material.

[0058] Given drying the wick represents such an important aspect of the present invention, below further discloses how it could be technically implemented considering the actual circumstances via some "smart control" ways.

[0059] Typically, people will use a humidifier if ambient air is dry (for instance, 30% RH and below). At a given temperature, the humidification rate is higher at lower ambient humidity levels. So during the operation of a humidifier, the more humid the air becomes (e.g. goes towards 50% RH and above), the slower the humidification rate becomes. This means that as the ambient humidity increases, the time required to dry a fully wet wick increases as well. The problem is that the humidifier will be typically switched off when ambient humidity is high (so needs a long after-run without water supply to dry the wick; shortening this duration is desired from user perspective as users expect an appliance to actually turn off once they switch it off).

[0060] In one embodiment of the present invention, in order to solve the just above-mentioned problem, specifically speaking, the flow rate of the water transportation to the wick 204 can be controlled to decrease as the ambient relative humidity increases as a result of the humidifier operation, on the condition that F ratio is less than 1, wherein the F ratio is defined as follow:

wherein, e is the total water evaporation rate indicative of the total amount of water which evaporates per unit time from the wick 204 at a specific ambient temperature and relative humidity, in ml/min; and f is the water supply rate towards the wick 204 by the water transporting means 210, in ml/min;

wherein the F ratio is being continuously decreased and approaches zero as the relative humidity approaches a threshold humidity level set by user.

[0061] Hence, the wick starts drying automatically and once the user decides to switch off the appliance, the wick dries much quicker.

[0062] This concept can be extended to an auto mode which ensure that the wick is already dry when the appliance reached its target value. This can be implemented using tables accessible by the controller. The table shown in Fig. 4 schematically shows the value interrelationship for F ratio and ambient relative humidity for an evaporative humidifier controlled under a water supply method according to one embodiment of the present invention.

[0063] When computing evaporation rate e, the control unit takes into account ambient humidity and temperature values as well as the air flow rate/fan speed of the fan, the table as shown in Fig. 4 could be used for a set value of 65% RH; water supply is stopped once 60% is reached (hence F of 0), and the remaining water content in the wick is sufficient to increase RH by remaining 5%. As a result, the wick is acceptably dry once 65% RH has been reached.

[0064] In addition, the present invention also provides a computer readable storage medium having computer readable program instructions embodied therewith for, when executed on a control unit, causing the control unit to implement any of the above mentioned embodiments of methods of supplying water.

[0065] Furthermore, similarly, the present invention also provides a computer program product comprising a computer readable storage medium having computer readable program instructions embodied therewith for, when executed on a control unit, causing the control unit to implement any of the above mentioned embodiments of methods of supplying water.

[0066] In a word, the present invention provides a system and a method of supplying water which can be applied on wick-based humidifier having separate compartments for the water tank and the wick. More specifically, the information about RH, temperature and fan setting of the humidifier can be used to control the flow rate of water to the wick.

[0067] The present invention is able to substantially reduce the microbial growth within an e.g. wick-based evaporative humidifier. In general, it's realized by applying water to the wick during usage only and making sure that the wick is dry in between usage. Hence, the inhibition of microbial growth can be achieved by: a) minimizing the time where microbial growth can actually occur on the wick; and b) inactivating microbes after each usage by desiccation.

[0068] When applied to a humidifier, inhibiting microbial growth will reduce risk of exposure to pathogens, maintenance frequency and smell nuisance.

[0069] Moreover, in contrast to current humidifiers, where the wick is located inside the actual water tank and therefore at least partially submerged by water, the present invention makes it possible that the entire wick surfaces is available for water evaporation as no portion of the wick is actually submerged in the water tank anymore, which results in higher humidification rates (hence better humidification performance) at same size of the wick or smaller wicks (hence smaller humidifier appliances) at same humidification rates.

[0070] At last, in the light of the present invention, a simple geometry of the water tank can be easily realized without any shade-causing structures and a simple UVC light source or the like be used to achieve homogenous irradiation of the entire water tank volume and its surfaces, and then an evaporative humidifier with simple architecture can be realized.

[0071] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "to comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0072] The invention further applies to a device comprising one or more of the characterizing features described in the description and/or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterizing features described in the description and/or shown in the attached drawings.

[0073] The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.

Claims

1. A water supply system (200) for an evaporative humidifier, comprising:

a wick holding chamber (202a), holding a wick (204) therein, the wick (204) being arranged for absorbing and containing water flew thereon to evaporate;

- a water tank (202b), storing the water therein for humidification, the water tank (202b) being physically separated from the wick (204);

- a water transporting means (210), connected to the wick holding chamber (202a) and the water tank (202b) respectively for transporting the water from the water tank (202b) to the wick (204) in the wick holding chamber (202a) during the humidification period and the prior preparation period thereof; and

- a control unit (212), connected to the water transporting means (210), the control unit (212) being configured to control the flow rate of the water transportation from the water tank (202b) to the wick (204).

2. The water supply system (200) according to claim 1, wherein the water transporting means (210) comprises a water driving means (207), a water tubing (208) and one or multiple water outlet nozzles (209); the water driving means (207) obtains the water in the water tank (202b) and drives the water by virtue of the water tubing (208) to the wick holding chamber (202a), the water is discharged onto the wick (204) via the water outlet nozzles (209) connected to the water tubing (208).

3. The water supply system (200) according to claim 2, wherein the control unit (212) is connected to the water driving means (207); the control unit (212) is configured to regulate the water driving means (207) in such a way that at least two different water flow rates (f_i, f_s) are applied, one initial water flow rate (f_i) for the preparation period and another one sustaining water flow rate (f_s) for the subsequent actual humidification period; the initial water flow rate (f_i) is equal or greater than the sustaining water flow rate (f_s).

4. The water supply system (200) according to claim 3, wherein the control unit (212) is configured to regulate the water driving means (207) in such a way that once the wick (204) is fully moistened during the preparation period, switching the initial water flow rate (f_i) to the sustaining water flow rate (f_s) for keeping the wick (204) exactly moist during the humidification period.

5. The water supply system (200) according to claim 4, wherein the state of fully moistened is defined by an algorithm inside the control unit (212) which powers the water driving means (207) at the initial water flow rate (f_i) for a predefined time period, whereby this time period is derived from the water uptake capacity of the dry wick (204) and the value of the initial water flow rate (f_i).

6. The water supply system (200) according to claim 1, wherein the humidifier comprises an air flow generating means (205), coupled to the wick (204) for generating an air flow (211) through and/or along the wick (204) with water vapor to carry away therefrom; the air flow generating means (205) comprises a fan, the fan sucks air outside the wick holding chamber (202a) to go through an air inlet (203) into the wick holding chamber (202a) and sucks/blows the air through and/or along the wick (204), so that moist air is released from the wick holding chamber (202a) via an air outlet (206) to produce humidification.

7. The water supply system (200) according to claim 6, wherein the control unit (212) is further connected to the air flow generating means (205), the control unit (212) is further configured to control the air flow generating means (205) to continue to generate the air flow (211) through and/or along the wick (204) for drying while stopping the water transportation to the wick (204) once the humidifier is instructed to be switched off until the wick (204) becomes acceptably dry.

8. The water supply system (200) according to claim 7, wherein the acceptably dry refers to a dry status that the wick (204) contains no greater than 5% of water.

9. A method of supplying water using the water supply system (200) for an evaporative humidifier of any of claims 1 to 8, comprising:

- receiving an instruction indicative of switching on the humidifier;

- activating the water transporting means (210) and transporting the water stored in the water tank (202b) to the wick (204) in the wick holding chamber (202a) during the humidification period and the prior preparation period thereof;

- wherein the flow rate of the water transportation from the water tank (202b) to the wick (204) is controlled in view of including different working phases, at least two different water flow rates (f_i, f_s) are applied, one initial water flow rate (f_i) for the preparation period and another one sustaining water flow rate (f_s) for the subsequent actual humidification period; the initial water flow rate (f_i) is equal or greater than the sustaining water flow rate (f_s).

10. The method of supplying water according to claim 9, wherein the initial water flow rate (f_i) corresponds to the water uptake capacity of the dry wick (204); and/or the sustaining water flow rate (f_s) corresponds to the water loss rate of the wick (204) due to water evaporation.

11. The method of supplying water according to claim 10, wherein the sustaining water flow rate (f_s) is a function of ambient temperature and ambient relative humidity or further plus air flow rate/fan speed through and/or along the wick (204).

12. The method of supplying water according to claim 11, wherein the flow rate of the water transportation to the wick (204) is controlled to decrease as the relative humidity increases on the condition that F ratio is less than 1; wherein the F ratio is defined as follow:

wherein,

e is the total water evaporation rate indicative of the total amount of water which evaporates per unit time from the wick (204) at a specific ambient temperature and relative humidity, in ml/min;

f is the water supply rate towards the wick (204) by the water transporting means (210), in ml/min;

wherein the F ratio is being continuously decreased and approaches zero as the relative humidity approaches a threshold humidity level set by user.

13. The method of supplying water according to claim 11 or 12, wherein the ambient temperature and the relative humidity in the wick holding chamber (202a) are derived from integrated sensors equipped on the humidifier or from external reference sources connected with the humidifier.

14. A computer readable storage medium having computer readable program instructions embodied therewith for, when executed on a control unit (212), causing the control unit (212) to implement the method of any of claims 9 to 13.

15. A computer program product comprising a computer readable storage medium having computer readable program instructions embodied therewith for, when executed on a control unit (212), causing the control unit (212) to implement the method of any of claims 9 to 13.

Drawing