EP0957326A2 - Process for cooling water or other flowing medium and apparatus therefor - Google Patents

Abstract

The fan (16) produces an air current (x) against the flow direction of the spray fluid in the cooling plant (10). In the lamella packet (22) run tubes (24) connected with one another, forming a delivery channel for a flow medium to be cooled, the temperature of which is different from that of the spray fluid separated from the flow medium.

Description

The invention relates to a method and a Cooling device for cooling water or the like. Flow media with trickle internals forming a slat package or Slat inserts below at least one Spray device in a spray room that is open at the top for spray liquids and at least one - preferred arranged around the side - below the trickle internals blowing fan or fan for generating a led against the flow direction of the spray liquid Airflow in the cooler.

Such cooling devices described in DE-C-26 59 767 with parallelepiped-like plate packs compiled, vertically spaced apart Gaps delimiting the lamella package, firmly built-in slat inserts - also as cooling towers designated - mainly used where chillers Need water in large quantities, for example in Cold stores, slaughterhouses, breweries and warehouses, at Air conditioning systems or skating installations as well as chemical equipment. The thing to cool back Fluid flows through spray nozzles as a spray liquid into the spray room and is countercurrent by it touching air cooled. The sprayed from the spray nozzles Liquid is generated after it emerges from the spray nozzle each a spray pattern, usually a spray cone.

Because an intimate connection between cooling water and air is required used to be only spray or fall water leading cooling towers by others with built-in trickle plants or packing to increase the surface replaced, the disadvantage of which is frequent clogging the flat trickle channels proved. This lack was made up for a combined design with spray space to form Large surface drops and an upstream zone from a relatively large distance from each other trending fillers fixed.

The most suitable for the mentioned applications Cooling towers or haze towers generally have Side-mounted fans for inserting supply air. The cooling air is then either above the trickle zones also on the side or - upwards.

In general, finned heat exchangers are used between two flow media of different temperatures one bring about a certain temperature compensation. In the Process engineering come for air / water and cooling purposes Air / air heat exchanger for use; with conventional Heat exchange processes will be water or another Liquid - - for example water / glycol mixture, Refrigerant, oil or the like - or air, especially circulating air of technical systems, using ambient air or exhaust air cooled by ventilation systems. In this cooling process can be cooled due to physical reasons Never below the temperature level of the medium Available cooling medium to be cooled.

In a method according to DE-C-42 15 898 by the applicant takes place at low ambient air temperatures Heat emission from the liquid to be treated Dry cooling; with increasing ambient air temperatures air humidification is connected upstream of dry cooling, by the in front of the heat exchanger from a secondary circuit Air is humidified at even higher Ambient air temperatures is used with dry cooling Humidification overlaid by wet cooling Sprinkling water of the secondary circuit over the Heat exchanger surface trickles and fresh air in the Counterflow is blown.

Knowing these facts, the inventor did it Goal set the heat exchange process with the help of the evaporation energy the on the surface of the heat exchanger sprayed liquid to improve as well as one hand to achieve multiple increases in cooling capacity and on the other hand, the outlet temperature of the medium to be cooled much below the temperature level of the Ambient atmosphere - possibly even that available stationary cooling medium.

The teaching of the independent leads to the solution of this task Claim; the subclaims give favorable further training on. In addition, all fall within the scope of the invention Combinations of at least two of those in the description, the drawing and / or the features disclosed.

According to the invention, the fluid medium is at least one conveyed in the slat package provided duct and in this is a spray liquid separated from it exposed whose temperature is different from temperature of the flow medium. The medium to be cooled Primary circuit flows into the top via a distributor Finned heat exchanger and leaves it at the bottom. At the The medium to be cooled flows through the heat exchanger the heat to be dissipated to that flowing in counterflow Exhale. The cooled medium is for cooling one Available to consumers. Since it is one closed loop, there are no losses in this primary circuit instead, and it's always a clean one Coolant circulating. At low ambient air temperatures the heat is given off by dry cooling. At the ambient air temperature increases to around 15 ° C Dry cooling overlaid on wet cooling.

A combination is within the scope of the invention as hybrid cooling wet and dry cooling for environmentally friendly Heat dissipation to the ambient air. With wet cooling The cooling takes place both through the evaporation of Water in the hybrid cooler as well as to a small extent by absorbing sensible heat from the colder Air. The principle of wet cooling is based on the high heat of evaporation of water, the principle of dry cooling on heat transfer only by convection. Hybrid cooling combines the advantages of wet and dry cooling, without accepting their disadvantages. With hybrid cooling at high ambient air temperatures due to evaporation, at medium ambient air temperatures Convection with evaporation and at low ambient air temperatures only cooled by convection.

An effective method of reducing investment costs is by spraying the heat exchanger depending on the cooling load. With this temporary spraying of the heat exchanger, an additional cooling effect can be achieved by evaporating the water on the surface of the heat exchanger. The cooling capacity can be increased to about two to four times by spraying the heat exchanger. it is thus possible, according to the invention, to cool the medium to be cooled below the ambient air temperatures. The dry design temperature can be set to approx. 6 ° C above the wet bulb temperature. In addition, the switch from dry cooling to wet cooling should take place at around t _u = 15 to 20 ° C.

According to a further feature of the invention is intended with everyone the spray patterns generated by spray nozzles of the spray device from spray liquid a spray area on the sprayed Surface of the plate pack as a heat exchanger generated as well as the spray areas close together be arranged touching or overlapping. As It has proven convenient to use the spray nozzles during the Spraying process to move across the surface and so too control that when moving in one direction the Sprayed surface as well as the spraying process during the idle stroke is interrupted in the opposite direction. Before another The spray nozzles are then supposed to move until the end an evaporation process of the previously sprayed Liquid should be stopped. The is preferred Spray liquid dosed so that it is applied largely completely evaporated.

Spraying brings, depending on the cooling load, metered and coordinated on the evaporation process, the corresponding optimal Amount of water on the surface of the heat exchanger. The way the amount of water applied can reduce the evaporation energy withdrawn for cooling.

Spraying is intermittent, i.e. H. it will only sprayed as much water as evaporated. The additional water saving compared to wet cooling is each according to design criteria, about 75%.

A washing device for automatic periodic cleaning the heat exchanger prevents deposits of dirt and minerals. It guarantees permanent, optimal heat transfer of the heat exchanger. The cleaning cycle is adjustable. For this purpose, the fan current is interrupted Spray nozzles instead of the aforementioned spray liquid Supplied cleaning liquid; the periodic changeover from one to the other of these liquids automatically controlled.

When lying within the scope of the invention, especially for Implementation of the procedure described Form cooling device with those running in the plate pack and interconnected pipes that have at least one Delivery channel for the fluid to be cooled, the Temperature - as described - to that of the Fluid separated spray liquid differently is, the latter by the air flowing in countercurrent from the radial fan or fan.

For cooling, the spray device should be several at a distance arranged to each other and separately controllable Spray nozzles included. Each of them is a spray area assigned; because the surface of the heat exchanger to be sprayed is divided into such spray areas according to the invention are arranged close to each other, touch each other or overlap.

The heat exchanger itself is preferred Design installed in a horizontal position, then the individual slats are arranged approximately vertically. The Direction of air flow through the heat exchanger vertically from the bottom up and flows through the Spaces between the individual slats. The Application of the water through the spray device happens opposite to the direction of air flow. The spray device preferably made of stainless steel for the intermittent application of water to the Heat exchanger surface and is on a horizontal back and forth movable carriage built on the Air outlet side above the heat exchanger is. The carriage with the rows of nozzles is turned across the heat exchanger moved back and forth with a linear drive. Here the stroke of the carriage preferably corresponds to the distance between neighboring ones Rows of nozzles. The number of rows of nozzles depends according to the width of the hybrid cooler. The lifting speed lies between 2 to 5 cm / sec and can for an optimal Dosage individually adjusted to the amount of water to be applied become.

The use of flat nozzles is of particular importance the spraying device; these should cross the lamellae of the Lamella pack oriented, and their spray pattern should be be a spray fan. The spray nozzle series are in Longitudinal direction of the heat exchanger and transverse to the Heat exchanger fins arranged. This ensures that if possible all finely sprayed water drops in the Slat package and not through the counter-flowing air is carried away or redirected.

The individual spray nozzles are arranged so that their Spray patterns immediately on or after impact touch the heat exchanger. The dosage of the spray water can change according to the characteristics of the spray nozzles the pressure in a range of preferably 1.0 to 5.0 bar can be adjusted.

So that an optimal evaporation can take place, both the dosage of the spray water as well as the sprinkling area of the heat exchanger can be chosen so that the applied water the evaporation energy released can be transferred to the medium to be cooled. The complete one Evaporation takes a minimal amount of time Air mixture and the temperature difference between the Air and the medium to be cooled depends. For this reason the spray water must be on the surface of the heat exchanger be sprayed on that surface unit in question is only sprayed again when the evaporation process is completed on this surface unit.

The evaporation losses are physical and depend on the heat transfer rate as well as on the atmospheric conditions. So they are Evaporation losses with an outside air condition of 32 ° C / 40 ° C maximum 1.49 kg / h per 1 kW Heat transfer performance.

According to the invention, the spray device is via a solenoid valve system supplied with spray water from a supply line. This solenoid valve is made by one with the fan for the air flowing through the plate pack - as well as with one on the water outlet side of the heat exchanger arranged temperature sensor - connected controller controlled.

If that temperature sensor exceeds the temperature setpoint displays, the drive of the spray device started, and at the same time all spray nozzles supplied with spray water via the solenoid valve. The Spray device covers a working stroke, whereby the Lamella pack is sprayed with water from the nozzles. At the The solenoid valve reaches the end point Spray water supply interrupted, causing the spray device returns to its original position in an idle stroke; there the drive of the spraying device for one predetermined time interrupted. After the interruption of the Spray water supply at the reversal point must be the pipe system according to the invention between the spray nozzles and the solenoid valve be kept under pressure so that when Starting the spraying device ensures that all spray nozzles spray water all over the surface at the same time spray. The spray nozzles are therefore after one another feature with an automatic locking mechanism equipped, which only after building up a corresponding performance pressure opens again.

The control of the spray duration, the stroke speed of the Spray device and the spray frequency, i.e. the duration of the individual spraying processes and the time intervals between them, is carried out by the regulator mentioned, which the mentioned Adapts parameters to the performance specifications and at the same time via the fan for the evaporation process sends the required air through the heat exchanger.

The device according to the invention is mainly used with higher requirements of the consumer to be cooled the cooling water quality, in dusty ambient air, at Cold places with narrow passages where it is important Prevent limescale deposits, sludge formation and corrosion, in case of water shortage, if the operator has questions in the Connection with water treatment, water drainage, Note the introduction of salt into the atmosphere, note the formation of steam if there is glycol / brine in the cooling water or a water temperature is above 65 ° C.

Thanks to the device according to the invention, the efficiency the cooling effect of the spray device on the Liquid applied to the surface of the heat exchanger the known systems greatly improved; this improvement is mainly due to the fact that the liquid until evaporation on the surface of the fins of the heat exchanger.

• relativ kleine Abmessungen der Vorrichtung;
• Abkühlung unter die Temperaturen der Umgebungsluft;
• geringere Investitionskosten als bei der Trockenkühlung;
• geringere Luftvolumenströme als bei der Trockenkühlung;
• keine Schwadenbildung;
• kein Wasserverbrauch bei Trockenkühlung;
• minimaler Frischwasserverbrauch bei Nasskühlung;
• Reduzierung des Zusatzwassers im Vergleich zur normalen Nasskühlung je nach Auslegungskriterien um etwa 75 - 85 %;
• kein Sekundärwasser - Umwälzkreislauf;
• keine Wassersammelwanne mit Wasserstand;
• die Wärmetauscheroberfläche bleibt stets sauber;
• die Kühlgrenze liegt etwa 6-8 K über der Feuchtkugeltemperatur (erreichbare Wasseraustrittstemperatur tWA = tF + 6 K);
• Trockenkühlung schon bei höheren Umgebungslufttemperaturen möglich;
• für Wassereintrittstemperaturen > 55°C geeignet;
• zuverlässiger Ganzjahresbetrieb (bei Betrieb mit Gefrierschutzmittel.

The advantages of the subject matter of the invention are:

• relatively small dimensions of the device;
• Cooling below ambient air temperatures;
• lower investment costs than with dry cooling;
• lower air volume flows than with dry cooling;
• no swath formation;
• no water consumption with dry cooling;
• minimal fresh water consumption with wet cooling;
• Reduction of make-up water compared to normal wet cooling by around 75 - 85% depending on the design criteria;
• no secondary water circulation circuit;
• no water collection tray with water level;
• the heat exchanger surface always remains clean;
• the cooling limit is about 6-8 K above the wet bulb temperature (achievable water outlet temperature t WA = t F + 6 K. );
• Dry cooling possible even at higher ambient air temperatures;
• suitable for water inlet temperatures> 55 ° C;
• reliable year-round operation (when operating with antifreeze.

Fig. 1:

eine Seitenansicht eines Lamellen-Wärmetauschers mit Sprüheinrichtung;

Fig. 2:

einen Horizontalschnitt durch einen Platten-Wärmetauscher mit Sprüheinrichtung;

Fig. 3:

eine Schrägsicht auf einen Teil eines weiteren mit einer verfahrbaren Sprüheinrichtung versehenen Wärmetauscher;

Fig. 4:

ein Schaltschema eines in eine Anlage eingebauten Wärmetauschers.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawing. Each shows a schematic representation in

Fig. 1:

a side view of a finned heat exchanger with spray device;

Fig. 2:

a horizontal section through a plate heat exchanger with spray device;

Fig. 3:

an oblique view of part of a further heat exchanger provided with a movable spray device;

Fig. 4:

a circuit diagram of a heat exchanger installed in a system.

A finned heat exchanger serving as a cooling device 10 for water has one on an end wall 12 box-like housing 14 a fan or Radial fan 16 on. Above that is in the housing 14 Plurality of parallel arranged - each defining a vertical plane - slats or Trickle internals 18 are provided, which are vertical between them Limit gap spaces 20 and one shown in FIG. 3 Form plate pack 22. The slats 18 horizontally penetrating tubes 24 form a multiple through the Slat package guided conveyor channel for a cooling Flow medium, for example for water.

Air sucked in by the fan 16, preferably ambient or Outside air is pressed into the housing 14 and flows through the gap or in the direction of the arrow x Spaces 20 of the horizontally aligned Lamella pack 22, at the top of which the air again exit.

Above the slats 18 and their upper edges 17 are arranged on the air outlet side spray nozzles, which against the spray direction 28 pointing the flow direction of the air generate the medium to be cooled as a spray liquid; these spray cones 28 are on the fins 18 of the Cooling device 10 directed to which the spray liquid evaporates. The energy required for this is almost exclusively the water cycle in the tubes 24 withdrawn. The plate pack 22 is intended as a heat exchanger no more spray liquid can be supplied than can be evaporated because it Evaporation rate does not increase and so does the cooling capacity does not continue to rise. It would also cause excess Spray liquid on the outer surfaces of the slats 19 drops form and the airside resistance in the gap spaces Enlarge 20 between the fins 18. This would in turn to an undesirable increase in air resistance to lead.

The individual spray nozzles 26 of the spray device 30 formed by them are supplied with the spray water via a modular solenoid valve system 32 which is connected to a feed line 31 and has a quantity of outputs corresponding to the number of spray nozzles 26 and is controlled by a controller 34 becomes. This is also connected via lines 36, 36 _a to the fan 16 and on the outlet pipe 24 _a to a temperature sensor 38 for the outlet temperature of the water from the heat exchanger. The individual solenoid valves of the modular solenoid valve system 32 are switched according to a predetermined control program and the individual spray areas 40 are sprayed accordingly with spray water.

So that a transfer of the evaporation energy released to the medium to be cooled by the liquid applied - as a prerequisite for optimal evaporation - Can take place, both the dosage of the spray liquid as well as the active area of the heat exchanger be chosen so that the liquid applied is the released evaporation energy on the medium to be cooled can transmit. Complete evaporation is needed a minimal amount of time from the air mixture temperature and humidity - as well as the temperature difference between depends on the air and the medium to be cooled. Out this is why the spray water gets onto the surface of the heat exchanger sprayed that the concerned Surface unit is only sprayed again when the Evaporation process completed on this surface is.

For the practical implementation of this requirement, the one to be sprayed Surface of the cooling device 10 according to FIG. 1 approximated square spray areas 40 divided, and each of these a separate spray nozzle 26 is assigned. The in the side view of FIG. 1 only with a limiting contour Spray areas 40 to be seen are close together arranged, preferably they touch or overlap slightly. The dosage of the spray water can by the characteristics of the spray nozzles 26 through Change in pressure in a range of preferably 1.0 to 5.0 bar can be adjusted.

The control of the spray duration per spray area 40 and the Spray frequency - i.e. the time intervals between the individual Spray processes - is carried out by that controller 34, the adapts the parameters mentioned to the performance requirements and at the same time via the fan 16 for the evaporation process required air through the heat exchanger sends.

Cleaning and keeping the surface clean the slats 18 are carried out - automatically controlled - periodically by means of the spray nozzles 26; this then a liquid instead of the spray water special cleaning agent while increasing the nozzle pressure given up, in this period of course the air flow through the plate pack 22 is interrupted is. However, are preferred for the cleaning process always activated all spray nozzles 26. Through this periodic Cleaning can contribute to optimal heat transfer constant cooling performance can be guaranteed.

In Fig. 2 is designed as a plate heat exchanger Cooling device 10a with a spray device 30 of the above described type, for which a diagonal Air flow is mandatory. The air for the Evaporation process must be diagonal according to arrow y from above are guided downwards, in Fig. 2 from the top right (Exhaust air 42) down to the left (exhaust air 44). The spray nozzles 26 are on the air inlet surface of the plate pack 22 arranged and spray the spray water approximately in Air flow direction y.

The air to be cooled also becomes diagonal according to arrow z led from top to bottom, but here from top left (Outside air 46) to the bottom right (supply air 44). The too Cooling air can also be reversed flow, diagonally from bottom to top. Of the Temperature sensor 38 measures the temperature of the chilled air.

Fig. 3 illustrates an embodiment of the Plate pack 22 from the parallel plates 18 of length a with these penetrating tubes 24, which - as I said - A conveying channel pulling through the disk pack 22 several times form for the medium to be cooled; the respective Pipe cross sections of the parallel pipes 24 are indicated at 25. It can also be seen that the - vertical planes E determining - outer surfaces 19 of the slats 18 each already mentioned gap or spaces 20 as trickle tracks limit for the spray liquid. Flows in these the air coming from the fan 16 in the flow direction x, preferably ambient or outside air, for cooling the Water from bottom to top.

Above the upper edges 17 of the fins 18 - that is, the air outlet side of the heat exchanger 10 - a carriage structure 50 is shown as a spray device. This offers several rows 52 of flat jet nozzles 26 _a running in the longitudinal direction of the heat exchanger 10, which are oriented transversely to the fins 18 or their upper edges 17 and each produce a spray fan 28 _a . This configuration ensures that as far as possible all of their fine liquid droplets get into the plate pack 22 and are not entrained and deflected by the counter-flowing air. The distances e between the individual flat jet nozzles 26 _a are selected such that adjacent spray compartments 28 _a touch immediately upon or after hitting the plate pack 22. The number - here two - of the nozzle rows 52 depends on the width a of this plate pack 22 or the housing 14. The chassis or the carriage 50 with the two rows 52 of flat jet nozzles 26 _a is parallel to the upper plate edges 17 and movably driven; the stroke dimension or the length b of the travel distance of the carriage 50 to its second end position 50 _e corresponds here approximately to the distance between adjacent rows of nozzles 52 from one another or the distance between the axial positions M and M _{e of} a central inlet pipe 53 of the spray device 50.

The spray device 50 is supplied with spray water via a solenoid valve 56 arranged in a feed line 31 and controlled by a controller 34. The controller 34 is also connected through the lines 36, 36 _a to the fan 16 and the temperature sensor 38 for the outlet temperature of the water from the heat exchanger 10. If the temperature sensor 38 registers that the temperature setpoint has been exceeded, the drive of the carriage or the spray device 50 is started, at the same time all spray nozzles 26 _{a are} supplied with spray water via the solenoid valve 56. The spray device 50, which is driven by a linear motor and is in the position at rest in the position shown with solid lines in FIG. 2, covers the working stroke b extending between the axial positions M, M _e of the inlet pipe 53. During this journey, the plate pack 22 is sprayed with the spray water from the spray nozzles 26 _a ; When the axis position M _e or the end position 50 _e is reached, the spray water supply is then interrupted by the solenoid valve 56, whereupon the spray device 50 returns to the line M in an idle stroke in order to be stopped there for a predetermined time. After interrupting the spray water supply on the axis line M _{e to} be regarded as a reversal point, the line system between the spray nozzles 26 _a and the solenoid valve 56 must be kept under pressure; when restarting the spray device 50, it must be ensured that all spray nozzles 26 _a spray the spray liquid simultaneously and over the entire area. Therefore, the spray nozzles 26 _{a are} equipped with an automatic closing mechanism which cannot be seen in the drawing and which only opens again after a corresponding line pressure has built up.

The control of the spray duration, the drive speed of the spray device 50 and the spray frequency of the spray nozzles 26, 26 _a - i.e. the duration of the individual spray processes and the time intervals between them - is carried out by that controller 34, which adapts the parameters mentioned to the performance specifications and simultaneously Via the fan 16, the air required for the evaporation process is sent via the heat exchanger 10.

The fin heat exchanger 10 - or in another embodiment also the plate heat exchanger 10 _a - is used in FIG. 3 as a hybrid cooler, that is to say as a combination of wet cooling and dry cooling. In the hybrid cooler, in which the conditions of wet cooling apply approximately, cooling is carried out by evaporation at high ambient air temperatures, by convection with evaporation at medium ambient air temperatures and only by convection at low ambient temperatures. With a temporary spraying of the heat exchanger 10, an additional cooling effect can be achieved by the evaporation of the water on the surface of the heat exchanger, and it is possible to cool the medium to be cooled below the ambient air temperatures. The dry design temperature can be set to about 6 ° C above the humidity temperature. Switching from dry cooling to wet cooling takes place approximately at t _u = 15 ° to 20 ° C.

The medium to be cooled - also preferably water / water glycol mixture or refrigerant - of a primary circuit 60 flows in its return 60 _a from a consumer 62 and after a ventilation branch 64 into a distributor 66 of the cooling device 10 _b ; the flow 60 _{b of} the primary circuit 60 is based on a collector 68. The medium to be cooled flows at up to 25 bar through the tubes 24 of the plate pack 22 and leaves it through the outlet tube 24 _a .

Spray water occurs as secondary water of a feed line 70 above into the plate pack 22 via the spray device 50 on. When flowing through the plate pack 22, this admits cooling medium the heat to be dissipated to the countercurrent x incoming air, and the cooled medium stands then available for cooling the consumer 62.

Any spray water losses that occur are discharged via a further collector 72 by emptying the water collecting trough. Otherwise, that supply line 70 starts from a mixing station 74 with a controller, which is connected via line 76 to a circulating pump 77 of the flow 60 _b ; another line 78 contains a temperature measuring device 38 _a . A control cabinet of the mixing station 74 with control for the cooling capacity control and the washing process is designed for a mains voltage of 230 / 400V, 50 Hz, in protection class IP55 according to VDE. There are no losses in the primary circuit 60 since it is a closed circuit and there is always a clean cooling medium in circulation. At low ambient air temperatures, heat is given off by dry cooling. When the ambient air temperature rises to around 15 ° C, wet cooling is superimposed on dry cooling.

The spray device 50 delivers, depending on the cooling load and matched to the evaporation process optimal amount of water on the surface of the heat exchanger. Of the The amount of water supplied in this way can reduce the evaporation energy withdrawn for cooling.

Spraying is intermittent, i.e. it will only be so much Water sprays as it evaporates. The additional saving - compared to wet cooling - depends on Design criteria about 75%. The one described Washing device for automatic periodic cleaning the heat exchanger prevents deposits of dirt and Minerals. It guarantees a permanent, optimal Heat transfer from the heat exchanger, and her Cleaning cycle is adjustable.

4 is used to drive the fan or radial fan 16 a speed-controlled three-phase standard motor used with frequency converter. The slat package 22 includes surface corrugated copper fins 18 which seamless copper pipes are drawn on; the latter become retrospective for anchoring the fins 18 mechanically on the pipes expanded. Distributors and collectors consist of Steel or copper, the frame made of copper sheet.

The corresponding - described on Fig. 3 - - arranged on the air outlet side above the heat exchanger 10, horizontally movable carriage - designed spray device 50 for intermittent application of water to the heat exchanger surface is preferably made of stainless steel (V2A). For spraying the water are molded flat jet nozzles 26 _a . intended. Here, too, the individual spray nozzles 26 _a are arranged in such a way that their spray compartments 28 _a touch immediately upon or after hitting the fins 18. The stroke dimension b of this carriage 50, which is moved by its linear drive, corresponds to the distance of its rows of nozzles 52 from one another, its stroke speed is between 2 to 5 cm / sec and can be individually adjusted for optimal metering of the amount of water to be applied.

The dosage of the spray water can be adjusted according to the characteristics of the spray nozzles 26 _a by changing the pressure in a range of preferably 1.0 to 5.0 bar. The spray device 50 is also used here for cleaning and keeping the heat exchanger 10 clean; it is periodically cleaned with a special cleaning agent and by increasing the nozzle pressure when the fan 16 is switched off. In this way, optimal heat transfer and constant cooling performance can always be guaranteed.

The hybrid system described in FIG. 4 is used at higher Requirements of the consumer 62 to be cooled on the quality of the cooling water, used in dusty ambient air as well at cooling points with narrow passages where it important is limescale, sludge formation and corrosion to prevent.

Claims (30)

Process for cooling water or the like in the cooling device,
characterized,
that the flow medium is passed through at least one delivery channel provided in the lamella package and is exposed therein to a spray liquid which remains separate from it, the temperature of which is different from the temperature of the flow medium. Process in which the spray nozzles Spraying device Spray patterns from spray liquid are generated according to claim 1, characterized in that with each of the spray patterns Spray area on the sprayed surface of the Lamella pack is generated as a heat exchanger and the Spray areas lying close to each other can be arranged touching or overlapping. A method according to claim 1 or 2, characterized characterized that the spray nozzles during the Spraying process moves over the surface while doing so be controlled so that when moving in a Sprayed towards the surface as well as the Spraying process interrupted during idle stroke in the opposite direction becomes. A method according to claim 3, characterized that the spray nozzles before a next spray movement until the end of an evaporation process previously sprayed spray liquid stopped becomes. Method according to one of claims 1 to 4, characterized characterized that the spray liquid doses so is sprayed that their amount with the evaporated amount of spray liquid in about Balance. Method according to one of claims 1 to 5, characterized characterized that the spray nozzles at interrupted fan flow a cleaning liquid spray. A method according to claim 6, characterized in that the periodic changeover of the supply of Spray liquid on cleaning liquid is controlled automatically. A method according to claim 6 or 7, characterized due to an increased nozzle pressure for the Cleaning process. Method according to one of claims 1 to 9, characterized characterized that at high Ambient air temperatures through evaporation, at average ambient air temperatures by convection with evaporation and at low ambient temperatures is only cooled by convection. Method according to one of claims 1 to 8, characterized characterized that the heat exchanger is dependent on the cooling load is sprayed. Method according to one of claims 1 to 10, characterized characterized that by intermittent spraying an additional one on the surface of the heat exchanger Cooling effect by evaporating the liquid this creates and the medium to be cooled under the Ambient air temperature is cooled. A method according to claim 11, characterized by a Dry design temperature to about 6 ° C above wet bulb temperature. Method according to one of claims 1 to 12, characterized in that a switchover from dry cooling to wet cooling is carried out at t _u = 15 to 20 ° C. Method according to one of claims 1 to 13, characterized characterized that the spray nozzles at a speed between 2 and 5 cm / sec over the sprayed Surface to be moved. Method according to one of claims 1 to 14, characterized characterized that the spray pressure in one area is set from 1.0 to 5.0 bar. Device for cooling liquid with trickle internals or lamellar inserts (18) forming a lamella packet (22) below at least one spray device (30, 50) in an upwardly open spray space for spray liquid and at least one fan or fan (16) blowing in below the trickle internals Generating an air flow (x) directed against the direction of flow of the spray liquid, in the cooling device (10, 10 _a , 10 _b ), in particular for carrying out the method according to at least one of the preceding claims, characterized in that the plate pack (22) runs and is connected to one another Pipes (24) form a delivery channel for a flow medium to be cooled, the temperature of which is different from the temperature of the spray liquid separated from the flow medium. Apparatus according to claim 16, characterized in that the spray device (30, 50) contains a plurality of spray nozzles (26, 26 _a ) which are arranged at a distance (e) from one another and are each separately controllable. Apparatus according to claim 16 or 17, characterized in that the surface of the heat exchanger (10, 10 _a ) to be sprayed is divided into spray areas (40) and one of the spray areas is assigned to each spray nozzle (26, 26 _a ). Device according to claim 18, characterized in that the spray areas (40) are arranged close to each other are touching or overlapping. Device according to one of Claims 15 to 18, characterized in that the spray nozzles (26, 26 _a ) of the spray device (30, 50) are arranged along a row (52) which is aligned in the longitudinal direction of the plate pack (22) and is adjustable transversely to the latter that spray images (28, 28 _a ) resulting from the spray liquid touch each other at or near the surface of the plate pack. Device according to claim 20, characterized in that the spray pattern of the spray nozzle (26) is a spray cone (28) is. Device according to one of claims 16 to 21, characterized in that the spray device (50) has a number of flat jet nozzles (26 _a ) which are oriented transversely to the fins (18) of the finned core (22) and the spray pattern of which each has a spray fan ( 28 _a ) is. Device according to one of claims 16 to 22, characterized characterized that in the longitudinal direction of the slats (18) of the disk pack (22) several of the Row of nozzles (52) provided and on a horizontal movable chassis or trolley as spraying device (50) are arranged. Device according to claim 23, characterized in that the dimension of the lateral working stroke (b) the distance Adjacent rows of nozzles (52) corresponds. Device according to claim 23 or 24, characterized in that the spray nozzles (26, 26 _a ) and the drive of the carriage (50) are controlled in such a way that, during a working stroke (b) of the carriage, spraying of the plate pack (22) in one direction can be triggered and the spraying process can be interrupted in the opposite direction during the idle stroke, it being possible for the carriage to be stopped before a next working stroke until an evaporation process has ended for the liquid previously sprayed onto the fins (18). Device according to one of claims 16 to 25, characterized in that in a spray water to the spray nozzles (26, 26 _a ) leading supply line (31) a solenoid valve (32) is provided, which is connected to the fan (16) for the Lamella pack (22) flowing air and controller (34) connected to a temperature sensor (38) can be controlled. Device according to one of claims 16 to 26, characterized in that the spray nozzle (26, 26 _a ) is equipped with an automatic closing mechanism. Apparatus according to claim 26 or 27, characterized in that the temperature sensor (38) is arranged on the water outlet side (24 _a ) of the heat exchanger. Device according to one of claims 16 to 28, characterized in that the spray nozzles (26, 26 _a ) of the spray device (30, 50) are arranged on a lamella heat exchanger as a cooling device (10, 10 _b ) on the outlet side of the cooling air flowing through the latter and the spray direction of the spray liquid against the flow direction (x) of the air stream is set (Fig. 1). Device according to one of claims 16 to 28, characterized in that the spray nozzles (26, 26 _a ) of the spray device (50) are arranged on a plate heat exchanger as a cooling device (10 _a , 10 _b ) on the inlet side of the cooling air flowing through the latter and the spray direction of the spray liquid is rectified with the air flow (Fig. 2).

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