SE2050833A1 - An air handling unit for a cooling system, and a method, performed by a control device, for an air handling unit - Google Patents

Abstract

The invention relates to an air handling unit (1) for a cooling system (3). The air handling unit (1) comprising: at least one component (2) configured to be exposed to a fluid (4), and a weight sensor device (9) arranged to measure the weight of the component (2) and/or the air handling unit (1). The invention also relates to a method, performed by a control device (100), for an air handling unit (1).

Description

An air handling unit for a cooling system, and a method, performed by a con-trol device, for an air handling unit.

TECHNICAL FIELD The invention relates to an air handling unit for a cooling system, and also to amethod, performed by a control device, for an air handling unit according to the ap-pended claims. Further, the invention relates to a computer program and to a com- puter-readable medium according to the appended claims.

BACKGROUND AND PRIOR ART Air handling units, such as evaporative humidifiers and cooler apparatuses, may beused to humidify and cool different types of spaces in buildings. Electric equipmentwithin a building may generate heat, which increases the temperature within thebuilding. increased temperature may decrease the performance of the equipment.Electric equipment may also be sensitive to static electricity. lf the humidity in aspace within the building falls below a certain level, static electricity may be gener-ated.

Evaporative humidifiers and cooler apparatuses comprises an inorganic non-com-bustible cooling and humidification media, also known as an evaporative media,which is a component configured to be exposed to a fluid. The fluid, such as water, issupplied to the top of the evaporative media via a fluid distribution element. The wa-ter flows down the evaporative media, which may have a corrugated surface. Aswarm and dry air passes through the evaporative media, it evaporates a proportion ofthe water and thus produces cold, humidified air. The rest of the water assists inwashing and cleaning the evaporative media, and is drained to a fluid tray. The warmand dry air may be directed through the evaporative media by means of a forced air flow, which is generated by a fan.

The energy that is needed for the evaporation of the fluid is taken from the air itself.The air that leaves the apparatus is therefore humidified and cooled simultaneously without any external energy supply for the evaporation due to an adiabatic coolingprocess.

The tray is filled with fluid from a fluid supply. When there is a humidity and coolingdemand, a pump starts and circulates the fluid over the evaporative media via thefluid distribution element. During start-up, an increased flow of fluid may be providedby the fluid distribution element, in order to increase the wetting of the evaporativemedia. When the evaporative media has absorbed the fluid, and is completely wet,the flow of fluid may be reduced to a normal level.

The fluid may contain a certain amount of minerals and salts with a predeterminedconcentration. During the evaporation, the fluid is released to the air. The mineralsand salts remain in the fluid and are returned to the fluid tray. A proportion of the fluidin the fluid tray is continually drained and replaced with fresh fluid from the supply inorder to control the mineral concentration.

Under periods, when the apparatus is inactivated, the evaporative media is dried bythe directed forced air flow from the fan after the fluid flow, supplied by the fluid distri-bution element, has been stopped.

Other types of air handling units are desiccant dehumidifiers, heat exchangers or fil-ter arrangements. Such air handling units treat air in various ways. During air han-dling, moisture in the air may be adsorbed by a component in the air handling unitconfigured to be exposed to the air/fluid, and thereafter released from the compo-nent. The component configured to be exposed to the fluid may be a desiccant rotorin the desiccant dehumidifier, a heat exchanger element in the heat exchanger and/or a mechanical, electrical or chemical filter element in the filter arrangement. ln addition to remaining minerals and salts in the fluid in contact with the air handlingunit, also bacteria, algae and fungi may be formed in the fluid and on the cooling andhumidification media. Minerals, salt, bacteria, algae and/or fungi in the fluid may alsoresult in deposits and sediments on the cooling and humidification media, resulting ina need for de-scaling of the cooling and humidification media. ln addition, minerals, salt, bacteria, algea and/or fungi in the fluid may also result in deposits and sedi-ments on the desiccant rotor in the desiccant dehumidifier, the heat exchanger ele-ment in the heat exchanger and/or the mechanical, electrical or chemical filter ele-ment in the filter arrangement, resulting in a need for de-scaling or replacing the des-iccant rotor, the heat exchanger element and/or the mechanical, electrical or chemi-cal filter element. Thus, a component of an air handling unit being exposed to a fluidmay be subject to deposits, sediments and scaling which may affect the functionalityof the air handling unit and/or may require service or de-scaling operations.

SUMMARY OF THE INVENTION Despite known solutions in the field, it would be desirable to develop an air handlingunit, which overcomes or alleviates at least some of the drawbacks of the prior art.

An object of the invention is thus to achieve an air handling unit, which facilitates de-termination of the status or condition of the air handling unit, and thereby improvesthe functionality/performance of the air handling unit.

Another object of the invention is to achieve an air handling unit, which facilitates de-tection of deposits and scaling.

A further object of the invention is to achieve a method for an air handling unit, whichfacilitates determination of the status or condition of the air handling unit, and therebyimproves the functionality/performance of the air handling unit.

Yet another object of the invention is to achieve a method for an air handling unit, which facilitates detection of deposits and scaling.

A further object of the invention is to develop a computer program and a computer-readable medium for executing the method.

These objects are achieved with the above-mentioned air handling unit, the above-mentioned method, performed by a control device, for an air handling unit and the above-mentioned computer program and computer-readable medium according to the appended claims.

According to an aspect of the invention an air handling unit for a cooling system isprovided. The air handling unit comprising: at least one component configured to beexposed to a fluid, and a weight sensor device arranged to measure the weight of thecomponent and/or the air handling unit.

The air handling unit may be an evaporative humidifier and cooler apparatus, a des-iccant dehumidifier, a heat exchanger or a filter arrangement. The air handling unitmay also be another type of apparatus, which handling air. The air handling unit maycool, humify, dehumify, clean and/or move air. The air handling unit may handling airinside and/or outside a defined space, such as a building. The component configuredto be exposed to fluid may be a cooling and humidification media, also known as anevaporative media, a desiccant rotor, a mineral removing media, a heat exchangerelement or a mechanical, electrical or chemical filter element. The fluid may be air,water, moisture, powder and/or chemical substances. Before, during and/or after op-eration of the air handling unit, the weight of the component and/or the air handlingunit may be measured by means of the weight sensor device. The weight sensor de-vice is arranged to measure the weight of the component and/or the air handling unit.The weight sensor device may be arranged under the component and/or the air han-dling unit, so that the component and/or the air handling unit rests on the weight sen-sor device. Alternatively, the component and/or the air handling unit may be sus-pended in the weight sensor device. By measuring the weight of the air handling unit,an indication of the status or condition of the component and/or the air handling unitmay be achieved. For example, the determined weight of the air handling unit/com-ponent may indicate the presence of deposits or scaling on the air handling unit/com-ponent. The weight may also indicate the distribution of fluid in the air handling unit.ln the event that the air handling unit is an evaporative humidifier and cooler appa-ratus, uneven wetting of the cooling and humidification media may occur due to clog-ging or similar. Furthermore, the weight may indicate the amount/level offluid in theair handling unit. ln the event that the air handling unit is an evaporative humidifierand cooler apparatus, during start-up the cooling and humidification media should be sufficiently wetted before activating the forced air flow through the cooling and humid-ification media. Normally, the wetting is performed during a predetermined time pe-riod in order to ensure sufficient wetting of the cooling and humidification media. Thismay cause a long start-up time of the apparatus and also decrease the performance.ln addition, an unnecessary flow of fluid during start-up of the evaporative humidifierand cooler apparatus may increase the water consumption. By determining theweight of the evaporative humidifier and cooler apparatus, it may easily be deter-mined when the cooling and humidification media is sufficiently wetted and the start-up time can thereby be reduced. Furthermore, when inactivating an evaporative hu-midifier and cooler apparatus, the directed forced air flow from the fan will continueafter the flow of fluid has been stopped, in order to dry the cooling and humidificationmedia. Normally, the fan is operated during a predetermined time in order to ensurethat the cooling and humidification media is sufficiently dry. By determining theweight of the evaporative humidifier and cooler apparatus, it may easily be deter-mined when the cooling and humidification media is sufficiently dry and the powerconsumption can thereby be decreased and the life span of the fan can be increased.Also, in cooling systems/applications where deposits and sediments of minerals andsalt are effective and useful in air handling units, such as in mineral removing media,a controlled volume of fluid should be added and exposed for the media in order tocreate the deposits and sediments. By means of the weight sensor device accordingto the present invention, the volume of fluid in the media can easily be determined and the supply of fluid can thereby efficiently controlled.

According to an aspect of the invention a method, performed by a control device, foran air handling unit is provided. The air handling unit comprises at least one compo-nent configured to be exposed to a fluid, and a weight sensor device for measuringthe weight of the component and/or the air handling unit. The method comprises re-ceiving weight data from the weight sensor device; and determining a current weightof the component and/or the air handling unit based on the weight data.

The weight data from the weight sensor device may be received before, duringand/or after operation of the air handling unit. Based on the determined currentweight of the component and/or the air handling unit, an indication of the statusand/or the condition of the component and/or the air handling unit may be achieved.

According to an aspect of the invention, a computer program is provided, the com-puter program comprising instructions which, when the program is executed by acomputer, cause the computer to carry out the method. Also, a computer-readabiemedium is provided, the computer-readable medium comprising instructions, whichwhen executed by a computer, cause the computer to carry out the method. This hasthe advantage that the method may be comprised in pre-programmed software,which may be implemented into the air handling unit suitable for utilizing the method.

Additional objectives, advantages and novel features of the invention will be apparentto one skilled in the art from the following details, and through exercising the inven-tion. While the invention is described below, it should be apparent that the inventionmay be not limited to the specifically described details. One skilled in the art, havingaccess to the teachings herein, will recognize additional applications, modificationsand incorporations in other areas, which are within the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS For fuller understanding of the present disclosure and further objects and advantagesof it, the detailed description set out below should be read together with the accom-panying drawings, in which the same reference notations denote similar items in the various figures, and in which: Fig. 1a schematically illustrates a front view of an air handling unit according to anexample; Fig. 1b schematically illustrates a side view of an air handling unit according to an ex-ample; Fig. 2 schematically illustrates a front view of an air handling unit comprising a de- scaling system according to an example; Fig. 3 schematically illustrates a front view of an air handling unit according to an ex-ample; Fig. 4 schematically illustrates a side view of an air handling unit according to an ex-ample; Fig. 5 schematically illustrates a side view of an air handling unit according to an ex- ample; Fig. 6 schematically illustrates a front view of an air handling unit according to an ex-ample; Fig. 7 shows a flowchart of a method according to an example; Fig. 8 shows a flowchart of a method according to an example; and Fig. 9 schematically illustrates a control device or computer according to an example.

DETAILED DESCRIPTION OF THE DRAWINGS According to the present disclosure an air handling unit for a cooling system is pro-vided. The air handling unit comprises at least one component configured to be ex-posed to a fluid, and a weight sensor device arranged to measure the weight of the component and/or the air handling unit.

The air handling unit may be an evaporative humidifier and cooler apparatus, a des-iccant dehumidifier, a heat exchanger or a filter arrangement. The air handling unitmay also be another type of apparatus, which handling air. The air handling unit maycool, humify, dehumify, clean and/or move air. The air handling unit may be com-prised in a cooling system. Such cooling system may comprise the air handling unitin the form of an evaporative humidifier and cooler apparatus. The air handling unitmay handlle air inside and/or outside a defined space, such as a building. The com-ponent configured to be exposed to fluid may be a cooling and humidification media,also known as an evaporative media, a desiccant rotor, a mineral removing media, aheat exchanger element or a mechanical, electrical or chemical filter element. The air handling unit may comprise a number of similar or different components configured to be exposed to the fluid. The component may be exposed to the fluid by a flow ofthe fluid passing by or through the component. The fluid may be air, water, moisture,powder and/or chemical substances. The fluid may treat or handle the air surround-ing the air handling unit or the air passing the component exposed to the fluid. Thesurrounding air may thus be treated and handled by the air handling unit, the compo-nent and the fluid. However, the air surrounding the air handling unit or the air pass-ing the component may be the fluid to be treated and handled by the air handling unitand the component. Before, during and/or after operation of the air handling unit, theweight of the component and/or the air handling unit may be measured. The weightsensor device is arranged to measure the weight of the component and/or the airhandling unit. The weight sensor device may be arranged under the componentand/or the air handling unit, so that the component and/or the air handling unit restson the weight sensor device. Alternatively, the component and/or the air handling unit may be suspended in the weight sensor device.

According to an example the weight sensor device comprises at least one load cell.

The load cell is sensitive for the weight of the component and/or the air handling unit.The weight sensor device may comprise only one load cell for measuring the weightof the component and/or the air handling unit. The weight sensor device may com-prise a number of load cells for measuring the weight of the component and/or the airhandling unit. The load cells may be arranged on different positions under the com-ponent and/or the air handling unit. A load cell positioned on one position under thecomponent and/or the air handling unit may measure a weight of the componentand/or the air handling unit which is different than the weight of another load cell po-sitioned at another position under the component and/or the air handling unit. Thesum of the weights measured by the different load cells may define the total weight ofthe component/air handling unit. The difference in weight between different load cellsmay indicate that the fluid is unevenly distributed in the component or that the com-ponent is exposed to scaling and should be cleaned. For example, a higher weightmeasured by load cells at a front side of the component/air handling unit compared tothe weight measured by load cells at a rear side of the component/air handling unitmay indicate scaling on the component/air handling unit. A number of load cells maybe connected at different positions to the component and/or the air handling unit and the component and/or the air handling unit may be suspended in the load cells. A dif-ference in measured weight between the load cells may indicate that the fluid is une-venly distributed in the component or that the component is exposed for scaling andshould be cleaned. A number of load cells for measuring the weight of the compo- nent and/or the air handling unit may increase the accuracy.

According to an example, the air handling unit further comprises a control deviceconnected to the weight sensor device for determining a current weight of the compo-nent and/or the air handling unit based on weight data from the weight sensor device.

The control device may receive weight data from the weight sensor device and deter-mine the current weight of the component and/or the air handling unit based on theweight data. The determined current weight of the component and/or the air handlingunit may be stored in a memory in the control device or in an external memory. Thecontrol device may be arranged at the air handling unit or the control device may bean external control device connected to the weight sensor device. The determinedcurrent weight of the component and/or the air handling unit may be presented on adisplay at the air handling unit. The determined current weight of the componentand/or the air handling unit may be transmitted to a control centre and/or to an opera-tor centre for the air handling unit.

According to an example, the control device is configured to detect a weight deviationbased on the weight data from the weight sensor device.

By determining the current weight of the component and/or the air handling unit a de-viation from a standard weight of the component and/or the air handling unit may bedetected. By determining the current weight of the component and/or the air handlingunit a deviation from the weight of the component and/or the air handling unit before,under or after operation of the component and/or the air handling unit may be de-tected. The weight deviation may indicate the status or condition of the air handlingunit. The control device may be configured to perform suitable actions based on thedetected weight deviation. One suitable action may be to start an alert or warning,which may be audibly and/or visually. The suitable action may depend on the type of deviation.

According to an example, the weight deviation is an increase of the current weight ofthe component and/or the air handling unit.

An increase of the weight may be determined by comparing the current weight with afirst threshold weight. The first threshold weight of the component and/or the air han-dling unit may correspond to a standard weight of the component and/or the air han-dling unit. The standard weight of the component and/or the air handling unit maycorrespond to the weight of an unused component and/or the air handling unit, i.e.the weight of the component and/or the air handling unit before it was put into opera-tion. Alternatively, the standard weight of the component and/or the air handling unitmay correspond to the weight during normal operation of the component and/or theair handling unit. An increase of the weight compared to the first threshold weightmay indicate scaling. A suitable action may be to activate a cleaning process. An al-ternative action may be to activate a warning or alert suggesting to replace the com-ponent According to an example, the weight deviation relates to a weight difference betweena plurality of different load cells of the weight sensor device. The weight sensor de-vice may comprise a plurality of load cells. The current weight is determined by thecontrol device as the sum of the weight data from each load cell. The control devicemay be configured to compare the weight data from each load cell and based on thisdetermine a difference in weight between the load cells. lf there is a deviation inweight between the different load cells, there might be a problem with the distributionof fluid through the component. Alternatively, a deviation in weight between the differ-ent load cells may indicate scaling on the component/air handling unit.

According to an example, the air handling unit is a direct evaporative humidifier andcooler apparatus or an indirect evaporative humidifier and cooler apparatus, and theat least one component is configured to evaporate the fluid to which it is exposed.

Direct and indirect evaporative humidifier and cooler apparatuses are used to humid-ify and cool different types of spaces in buildings. ln the direct evaporative humidifierand cooler apparatus, the component configured to evaporate the fluid to which it is 11 exposed may comprise an inorganic non-combustible cooling and humidification me-dia, also known as an evaporative media. The fluid, such as water, is supplied to thetop of the evaporative media via a fluid distribution element. The fluid, received andevaporated by the media, may be water or any other suitable fluid which may beevaporated by the media. The fluid may preferably be environmentally friendly. Thewater flows down the evaporative media, which may have a corrugated surface. Thefluid may flow over and through the evaporative media by means of gravity. As warmand dry air passes through the evaporative media, it evaporates a proportion of thewater and thus produces cold, humidified air.

The apparatus may increase the humidity in air or keep the humidity in air at a prede-termined level. The apparatus may also decrease the temperature of air or keep thetemperature at a constant level. The cooling and humidification media is made of amaterial which is able to receive and evaporate a fluid. The cooling and humidifica-tion media may have a corrugated surface, which increases the surface of the media.The cooling and humidification media may be arranged in cassettes, which are sup-ported by a rigid frame of the apparatus.

The warm and dry air may be directed through the evaporative media by means of aforced air flow, which is generated by a fan. The rest of the water assists in washingand cleaning the evaporative media, and is drained to a fluid tray. The tray is filledwith fluid from a fluid supply. When there is a humidity and cooling demand, a pumpstarts and circulates the fluid over the evaporative media via the fluid distribution ele-ment. During start-up, an increased flow of fluid may be provided by the fluid distribu-tion element, in order to increase the wetting of the evaporative media. When theevaporative media has absorbed the fluid, and is completely wet, the flow of fluidmay be reduced to a normal level. The fluid may contain a certain amount of mineralsand salts with a predetermined concentration. During the evaporation, the fluid is re-leased to the air. The minerals and salts remain in the fluid and are returned to thefluid tray. A proportion of the fluid in the fluid tray is continually drained and replacedwith fresh fluid from the supply in order to control the mineral concentration. Underperiods, when the apparatus is inactivated, the evaporative media may be dried bythe directed forced air flow from the fan after the fluid flow, supplied by the fluid distri-bution element, has been stopped. 12 ln addition to the inorganic non-combustible cooling and humidification media used inthe direct evaporative humidifier and cooler apparatus, the indirect evaporative hu-midifier and cooler apparatus may use heat exchangers comprising units of tubes,which on the outside are subjected to fluid, such as water. Warm and dry air may bedirected through the heat exchangers by means of a forced air flow, which is gener-ated by the fan. A proportion of the water on the surface of the heat exchangersevaporates by the airflow and thus produces cold, humidified air.

The weight sensor device arranged to measure the weight of the component and/orthe air handling unit may be arranged under the cooling and humidification mediaand/or under the direct or indirect evaporative humidifier and cooler apparatus. Theweight sensor device may comprise a plurality of load cells. The load cells may be ar-ranged on different positions under the cooling and humidification media and/or un-der the direct or indirect evaporative humidifier and cooler apparatus. One load cellmay be arranged under each corner of the cassette in which the cooling and humidifi-cation media are arranged. One load cell may be arranged under each corner of the rigid frame of the direct or indirect evaporative humidifier and cooler apparatus.

A load cell positioned under one corner of the cassette and/or of the rigid frame maymeasure a weight of the cooling and humidification media and/or under the direct orindirect evaporative humidifier and cooler apparatus, which is different than theweight of another load cell positioned under another corner of the cassette and/or ofthe rigid frame. This difference in weight may indicate that the fluid is uneven distrib-uted in the cooling and humidification media or that the cooling and humidificationmedia is exposed for scaling and should be cleaned.

Alternatively, a number of load cells may be connected at different positions to thecassette and/or of the rigid frame and the cassette and/or of the rigid frame may besuspended in the load cells. A difference in measured weight between the load cellsmay indicate that the fluid is uneven distributed in the cooling and humidification me-dia or that the cooling and humidification media is exposed for scaling and should becleaned. 13 According to the present disclosure, a method, performed by a control device, for anair handling unit is provided. The air handling unit comprising: at least one compo-nent configured to be exposed to a fluid, and a weight sensor device for measuringthe weight of the component and/or the air handling unit. The method comprising: re-ceiving weight data from the weight sensor device; and determining a current weight of the component and/or the air handling unit based on the weight data. lt is to be understood that features and advantages mentioned in relation to the airhandling unit as disclosed herein is also applicable on the method. The method isperformed by the control device. The control device may receive weight data from theweight sensor device and determine the current weight of the component and/or theair handling unit based on the weight data. The determined current weight of thecomponent and/or the air handling unit may be stored in a memory in the control de-vice or in an external memory. The control device may be arranged at the air han-dling unit. The determined current weight of the component and/or the air handlingunit may be presented on a display at the air handling unit. The determined currentweight of the component and/or the air handling unit may be transmitted to a control centre and/or to an operator centre for the air handling unit.

According to an example, the method further comprises detecting a weight deviationbased on the weight data from the weight sensor device. By determining the currentweight of the component and/or the air handling unit a deviation from a standardweight of the component and/or the air handling unit may be detected. By determin-ing the current weight of the component and/or the air handling unit a deviation fromthe weight of the component and/or the air handling unit before, under or after opera-tion of the component and/or the air handling unit may be detected. The method mayfurther comprise performing suitable actions based on the detected weight deviation.The suitable action may depend on the type of deviation.

According to an example, detecting a weight deviation comprises detecting an in-crease of the current weight of the component and/or the air handling unit. Detectinga weight deviation may thus comprise comparing the current weight with a firstthreshold weight, and based on the comparison determine an increase of the weight. 14 According to an example, detecting a weight deviation comprises detecting a weightdifference between a plurality of different load cells of the weight sensor device. Thedifference in weight may indicate that the fluid is unevenly distributed in the compo-nent or that the component is exposed for scaling and should be cleaned.

According to an example, the method further comprises activating a cleaning process of the component in order to remove scaling from the component.

A weight deviation may indicate that the component is exposed for scaling andshould be cleaned. A suitable action may thus be to activate a cleaning process of the component in order to remove scaling from the component.

The type of cleaning process may be performed based on the condition of the com-ponent. Dependent on the condition of the component, at least one cleaning fluid issupplied to the component. Data received by the method is processed in the controldevice and based on the data a suitable cleaning fluid or a combination of cleaningfluids may be supplied to the component. The at least one cleaning fluid may be sup-plied directly to the component or to the fluid, which is distributed by the fluid distribu-tion element to the component. When supplying the at least one cleaning fluid to thecomponent, the air handling unit will be cleaned.

According to an example, the method further comprises providing an alert regardingthe detected deviation.

When a weight deviation has been detected, a suitable action may be to provide analert or warning, so that service can be performed to identify if there is a stop some-where in the component affecting the fluid distribution or if there is scaling on thecomponent. The alert or warning may be audibly and/or visually. The alert or warningmay be presented on a display at the air handling unit. The alert or warning may betransmitted to a control centre and/or to an operator centre for the air handling unit.

The present disclosure also relates to a computer program comprising instructionswhich, when the program is executed by a computer, causes the computer to carryout the method disclosed above. The invention further relates to a computer-readable medium comprising instructions, which when executed by a computer causes thecomputer to carry out the method disclosed above. The method may be comprised inpre-programmed software, which may be implemented into the drilling unit suitablefor utilizing the method. The pre-programmed software may be stored in the controldevice. Alternatively, or in combination, the software may be stored in a memory or in computer at a distance from the control device.

The air handling unit for a cooling system, the method, performed by a control de-vice, for an air handling unit, the computer program and the computer-readable me- dium will now be described together with the appended drawings.

Figures 1a and 1b schematically illustrate a front view and a side view of an air han-dling unit 1 according to an example. The air handling unit1 may be comprised in acooling system 3. The air handling unit 1 comprises at least one component 2 config-ured to be exposed to a fluid 4. The air handling unit 1 is an evaporative humidifierand cooler apparatus 1, and the component 2 is configured to evaporate the fluid 4 towhich it is exposed. ln a direct evaporative humidifier and cooler apparatus 1 thecomponent 2 is also known as an evaporative media or a cooling and humidificationmedia 2. The cooling and humidification media 2 may be arranged in cassettes 5,which are supported by a rigid frame 7 of the evaporative humidifier and cooler appa-ratus 1.The evaporative humidifier and cooler apparatus 1 may be a direct evapora-tive humidifier and cooler apparatus 1 or an indirect evaporative humidifier and coolerapparatus 1. ln the indirect evaporative humidifier and cooler apparatus 1 the compo-nent 2 may be a heat exchanger. Alternatively, the indirect evaporative humidifierand cooler apparatus 1 may comprise a cooling and humidification media 2 and aheat exchanger. A weight sensor device 9 is arranged to measure the weight of theevaporative media 2 and/or the evaporative humidifier and cooler apparatus 1. Theweight sensor device 9 comprises load cells 11, which are arranged under the evap-orative humidifier and cooler apparatus 1. The load cells 11 are arranged on differentpositions under the cooling and humidification media 2 and/or under the direct or indi-rect evaporative humidifier and cooler apparatus 1. ln figures 1a and 1b, one loadcell 11 is arranged under each corner of the rigid frame 7 of the evaporative humidi- 16 fier and cooler apparatus 1. ln the indirect evaporative humidifier and cooler appa-ratus 1, the load cells 11 may be arranged on different positions under the heat ex-changer and/or under the indirect evaporative humidifier and cooler apparatus 1.

A control device 100 is connected to the load cells 11 for determining a currentweight of the evaporative media 2 and/or the evaporative humidifier and cooler appa-ratus 1 based on weight data from the weight sensor device 9 comprising the loadcells 11. The control device 100 is configured to detect a weight deviation based onthe weight data from the weight sensor device 9 comprising the load cells 11 _ Theweight deviation may an increase of the current weight of the evaporative media 2and/or the evaporative humidifier and cooler apparatus 1. The weight deviation re-lates to a weight difference between the plurality ofdifferent load cells 11 of theweight sensor device 9.

The cooling and humidification media 2 is configured to receive and evaporate thefluid 4. A fluid distribution element 6 is configured to distribute the fluid 4 to the cool-ing and humidification media 2. A tray 8 is arranged to collect fluid 4 downstream ofthe cooling and humidification media 2. The fluid 4 distributed by the fluid distributionelement 6 is collected from the tray 8. A first fluid pump 18 is be connected to thefluid distribution element 6, wherein the first fluid pump 18 is configured to deliverfluid 4 to the fluid distribution element 6. The first fluid pump 18 is arranged at a fluidpipe arranged between the tray 8 and the fluid distribution element 6. The first fluidpump 18 may suck the fluid 4 from the tray 8 and deliver the fluid 4 to the fluid distri-bution element 6. Vertically directed arrows 23 represent the direction of fluid 4through the fluid distribution element 6, the cooling and humidification media 2 andfurther to the fluid tray 8. A fan 42 is configured to generate an air flow 44 through the cooling and humidification media 2.

Fig. 2 schematically illustrates a front view of an air handling unit 1 for a cooling sys-tem 3 according to an example. The air handling unit 1 comprises a cleaning system13 for removing scaling from the component 2. The air handling unit 1 is according tothe example an evaporative humidifier and cooler apparatus 1 for humidification andcooling of air. A fluid supply tank 20 is in fluid connection with the tray 8 by a fluidpipe. Fluid 4 may be supplied to the tray 8 from the fluid supply tank 20. The fluid 4 17 from the fluid supply tank 20 is supplied to the tray 8 by a second fluid pump 22. Adrain valve 24 is arranged at the tray 8 and the fluid 4 in the tray 8 is may be drainedvia the drain valve 24. An additional sensor device 26 may be connected to the con-trol device 100, which additional sensor device 26 is may detect temperature and hu-midity in the air surrounding the evaporative humidifier and cooler apparatus 1.

The control device 100 is connected to a sensor device 10. The control device 100 isconfigured to determine the condition of the cooling and humidification media 2based on data from the sensor device 10 arranged in fluid communication with thefluid 4 downstream of the cooling and humidification media 2. The condition of thecooling and humidification media 2 may be determined by determining the pH-value,hardness, turbidity, salt content, and/or presence of bacteria/fungi in the fluid 4 down-stream of the cooling and humidification media 2. Depending on the condition of themedia 2, a first cleaning fluid 12 and/or a second cleaning fluid 14 will be supplied tothe cooling and humidification media 2.

A container 16 is provided, which contains the fluid 4 and the first and second clean-ing fluids 12, 14. The fluids 4, 12, 14 are separated from each other in the containerby partition walls 28 arranged in the container 16. Three independent containers mayalso constitute the container 16. According to the first example, the part of the con-tainer 16 comprising the fluid 4 is arranged in fluid communication with the tray 8 bymeans of a pipes comprising a fourth fluid pump 30 and a fifth fluid pump 32 and afirst valve 34. The part of the container 16 containing the fluid 4 also comprising thesensor device 10. The control device 100 is configured to circulate fluid 4 from thetray 8 to the part of the container 16 containing the fluid 4. The parts of the container16 containing the first and second cleaning fluids 12, 14 are in fluid connection withthe tray 8 by pipes comprising a third fluid pump 36 and a second valve 38 and thirdvalve 40.

The control device 100 is configured to supply the first and/or second cleaning fluid12, 14 to the cooling and humidification media 2 by supplying the first and/or cleaningfluid 12, 14 to the tray 8. The control device 100 is configured to supply a first clean-ing fluid 12 to the cooling and humidification media 2 when the cooling and humidifi-cation media 2 has a condition requiring descaling of the cooling and humidification 18 media 2. The control device 100 is configured to supply a second cleaning fluid 14 tothe cooling and humidification media 2 when the cooling and humidification media 2has a condition requiring disinfection of the cooling and humidification media 2. ln ad-dition, based on the condition of the cooling and humidification media 2, the controldevice 100 is configured to determine a dosage of the first and/or cleaning fluid 12, 14. The control device 100 is connected to the load cells 11.

Fig. 3 schematically illustrates a front view of an air handling unit 1 according to anexample. An additional cooling and humidification media 2' and an additional fluiddistribution element 6' are arranged on and above the cooling and humidification me-dia 2 and the fluid distribution element 6 shown in figures 1a, 1b or 2. The tray 8 is influid communication with both the cooling and humidification media 2 and the fluiddistribution element 6, and the additional cooling and humidification media 2' and anadditional fluid distribution element 6' via fluid pipes. A fourth valve 48 is arrangedbetween the first fluid pump 18 and the fluid distribution element 6. A fifth valve 50 isarranged between the first fluid pump 18 and the additional fluid distribution element6'.

The fluid distribution element 6 comprises connection means 52, for connecting thefluid distribution element 6 to the additional cooling and humidification media 2'. Theadditional fluid distribution element 6' is configured to transfer the fluid 4, which is dis-tributed by the additional fluid distribution element 6', to the additional cooling and hu-midification media 2' and further to the cooling and humidification media 2.

Fig. 4 schematically illustrates a side view of an air handling unit 1 according to anexample. ln this example the component 2 configured to be exposed to fluid 4 is adesiccant rotor 54 in a desiccant dehumidifier 56. The fluid 4 may be air. The desic-cant dehumidifier 56 comprising the desiccant rotor 54, which is provided with chan-nels 55, a filter element 58 for separating particles from a process airflow 60, and aprocess air fan 42 for generating the process airflow 60 through the channels 55 ofthe desiccant rotor 54 and through the filter element 58. The component 2 configuredto be exposed to the fluid 4 may also be the filter element 58. The desiccant rotor 54is connected to a propulsion unit 64, such as a motor, for rotating the desiccant rotor 19 54. The desiccant rotor 54 is arranged on a shaft 66, which is configured to be ro-tated by the propulsion unit 64. The desiccant rotor 54 comprises a housing 68,which is provided with a process air inlet opening 70, a process air outlet opening 72,a reactivation air inlet opening 74 and a reactivation air outlet opening 76. A weightsensor device 9 is arranged to measure the weight of the desiccant rotor 54. Theweight sensor device 9 comprises load cells 11, which are arranged at the routableshaft 66. One load cell 11 is arranged on each side of the desiccant rotor 54.

Fig. 5 schematically illustrates a side view of an air handling unit 1 according to anexample. ln this example the component 2 configured to be exposed to fluid is heatexchanger elements 78, 79 in a condensate dehumidifier 80 according to an exam-ple. The air handling unit 1 is the condensate dehumidifier 80. The fluid 4 may be air.A first heat exchanger element 78 in the condensate dehumidifier 80 is an evaporator78. A process air fan 42 in the dehumidifier 80 is configured to generate a processairflow 60 through the evaporator 78. A filter element 58 will separating particles fromthe process airflow 60 and thus prevent the particles from reaching the evaporator78. A component 2 configured to be exposed to the fluid 4 may also be the filter ele-ment 58. A second heat exchanger element 79 in the condensate dehumidifier 80 isa condenser 79. The evaporator 78 is connected to a compressor 82. The condenser79 is also connected to the compressor 82. The evaporator 78, condenser 79 andcompressor 82 are parts of a refrigeration device 84. The condensate dehumidifier80 condenses moisture in the air, which moisture thus is removed from the air andcollected as water in a tray 8. Thereafter, the dried air is reheated by the condenser79 of the refrigeration device 84 of the dehumidifier 80. Finally, the dehumidified, re-warmed airflow is released into the ambient space as dried airflow 85 through an out-let opening 86 in a housing 68 of the condensate dehumidifier 80. A weight sensordevice 9 is arranged to measure the weight of heat exchangers 78, 79. The weightsensor device 9 comprises load cells 11, which are arranged at the heat exchangers78, 79. One load cell 11 is arranged under the evaporator 78, and another load cell11 is arranged under the condenser 79.

Fig. 6 schematically illustrates a front view of an air handling unit 1 according to anexample. According to this example the air handling unit 1 is be suspended in the weight sensor device 9. A number of load cells 11 are connected at different posi-tions to the air handling unit 1 and the air handling unit 1 is suspended in the loadcells 11. The load cells 11 are connected to the rigid frame 7 of the air handling unit 1and wires and/or chains 86 are connected to the load cells 11. The wires and/orchains 88 are connected to a ceiling 90.

Fig. 7 shows a flowchart of a method according to an example. The method is per-formed by a control device 100, for an air handling unit 1. The method relates to theair handling unit 1 for a cooling system disclosed in figures 1 - 5. The air handlingunit 1 thus comprises at least one component 2 configured to be exposed to a fluid 4,and a weight sensor device 9 for measuring the weight of the component 2 and/orthe air handling unit 1.

The method comprising: receiving s101 weight data from the weight sensor device 9;and determining s102 a current weight of the component 2 and/or the air handlingunit 1 based on the weight data.

Fig. 8 shows a flowchart of a method according to an example. The method accord-ing to this example is performed by a control device 100, for an air handling unit 1.The method relates to the air handling unit 1 for a cooling system disclosed in figures1 - 5. The air handling unit 1 thus comprises at least one component 2 configured tobe exposed to a fluid 4, and a weight sensor device 9 for measuring the weight of thecomponent 2 and/or the air handling unit 1.

The method according to this example comprising: receiving s101 weight data fromthe weight sensor device 9; determining s102 a current weight of the component 2and/or the air handling unit 1 based on the weight data; detecting s103 a weight devi-ation based on the weight data from the weight sensor device 9, wherein detectings103 a weight deviation comprises detecting s103 an increase of the current weightof the component 2 and/or the air handling unit 1; wherein detecting s103 a weightdeviation comprises detecting s103 a weight difference between a plurality of differ-ent load cells 11 of the weight sensor device 9; activating s104 a cleaning process ofthe component 2 in order to remove scaling from the component 2, and providings105 an alert regarding the detected deviation. 21 Fig. 9 schematically illustrates a diagram of a version of a device 500. The controldevice 25 described with reference to fig. 1 may in a version comprise the device500. The device 500 comprises a non-volatile memory 520, a data processing unit510 and a read/write memory 550. The non-volatile memory 520 has a first memoryelement 530 in which a computer programme, e.g. an operating system, is stored forcontrolling the function of the device 500. The device 500 further comprises a buscontroller, a serial communication port, I/O means, an A/D converter, a time and dateinput and transfer unit, an event counter and an interruption controller (not depicted).

The non-volatile memory 520 has also a second memory element 540.

There is provided a computer programme P which comprises instructions for carryout the above-mentioned method. The programme P may be stored in an executable form or in a compressed form in a memory 560 and/or in a read/write memory 550.

Where the data processing unit 510 is described as performing a certain function, itmeans that the data processing unit 510 effects a certain part of the programmestored in the memory 560 or a certain part of the programme stored in the read/writememory 550.

The data processing device 510 can communicate with a data port 599 via a databus 515. The non-volatile memory 520 is intended for communication with the dataprocessing unit 510 via a data bus 512. The separate memory 560 is intended tocommunicate with the data processing unit 510 via a data bus 511. The read/writememory 550 is adapted to communicating with the data processing unit 510 via adata bus 514.

When data are received on the data port 599, they are stored temporarily in the sec-ond memory element 540. When input data received have been temporarily stored,the data processing unit 510 is prepared to effect code execution as described above.

Parts of the methods herein described may be effected by the device 500 by meansof the data processing unit 510 which runs the programme stored in the memory 560 22 or the read/write memory 550. When the device 500 runs the programme, methods herein described are executed.

The foregoing description of the preferred embodiments of the present invention isprovided for illustrative and descriptive purposes. lt is not intended to be exhaustiveor to restrict the invention to the variants described. Many modifications and varia-tions will obviousiy be apparent to one ski||ed in the art. The embodiments have beenchosen and described in order best to explain the principles of the invention and itspractical applications and hence make it possible for specialists to understand the in-vention for various examples and with the various modifications appropriate to the in- tended use.

Claims (15)

1. An air handling unit (1)for a cooling system (3), the air handling unit (1) compris-ing: at least one component (2) configured to be exposed to a fluid (4), and a weight sensor device (9) arranged to measure the weight of the component(2) and/or the air handling unit (1 ).

2. The air handling unit (1) according to claim 1, wherein the weight sensor device (9)comprises at least one load cell (11).

3. The air handling unit (1) according to claim 1 or 2, further comprising: a control device (100) connected to the weight sensor device (9) for determin-ing a current weight of the component (2) and/or the air handling unit (1) based onweight data from the weight sensor device (9).

4. The air handling unit (1) according to claim 3, wherein the control device (100) isconfigured to detect a weight deviation based on the weight data from the weightsensor device (9).

5. The air handling unit (1) according to claim 4, wherein the weight deviation is anincrease of the current weight of the component (2) and/or the air handling unit (1 ).

6. The air handling unit (1) according to claim 4 or 5, wherein the weight deviation re-lates to a weight difference between a plurality of different load cells (1 1) of theweight sensor device (9).

7. The air handling unit (1) according to any one of the preceding claims, wherein theair handling unit (1) is a direct evaporative humidifier and cooler apparatus or an indi-rect evaporative humidifier and cooler apparatus, and the at least one component (2)is configured to evaporate the fluid (4) to which it is exposed.

8. A method, performed by a control device (100), for an air handling unit (1 ), the airhandling unit (1) comprising: at least one component (2) configured to be exposed toa fluid (4), anda weight sensor device (9) for measuring the weight of the component (2) and/or theair handling unit (1), the method comprising: receiving (s101) weight data from the weight sensor device (9); and determining (s102) a current weight of the component (2) and/or the air han-dling unit (1) based on the weight data.

9. The method according to claim 8, further comprising:detecting (s103) a weight deviation based on the weight data from the weightsensor device (9).

10. The method according to claim 9, wherein detecting (s103) a weight deviationcomprises detecting an increase of the current weight of the component (2) and/orthe air handling unit (1 ).

11. The method according to claim 9 or 10, wherein detecting (s103) a weight devia-tion comprises detecting (s103) a weight difference between a plurality of differentload cells (1 1) of the weight sensor device (9).

12. The method according to claim 10, further comprising:activating (s104) a cleaning process of the component (2) in order to removescaling from the component (2).

13. The method according to any one of claim 9-12, further comprising: providing (s105) an alert regarding the detected deviation.

14. A computer program (P) comprising instructions which, when the program is exe-cuted by a computer (100; 500), cause the computer (100; 500) to carry out the method according to any one of claims 8-13.

15. A computer-readable medium comprising instructions, which when executed by acomputer (100; 500), cause the computer (100; 500) to carry out the method accord-ing to any one of claims 8-13.