AT517013A1 - Water tempered air conditioning system with condensation heat recovery - Google Patents

Abstract

Air conditioning system consisting of 3 plate heat exchangers (A, B, C), 4 fans (5,6,7,8) or blowers and 4 control elements (V1, V2, V3, V4) and external cold or hot water supply (3a, 3b, 3c , 3d, 3e), wherein the first heat exchanger (A) is an air-air heat exchanger with Kondensationswasserrückführung (4a) in the exhaust air (1d), the second heat exchanger (B) an air-water plate heat exchanger to dew point reduction of the fresh air (2b) where the condensed water (4b) is also evaporated in the exhaust air (1d) of the first heat exchanger (A), and the third heat exchanger (C) is an air-water plate heat exchanger for indoor air cooling (13), these three heat exchangers (A, B (C) being integrated in a system so as to form a single block of slabs with substantially horizontal plates (9, 10), where on each plate one sector is assigned to each of the three heat exchangers involved and connecting channels are interconnected by webs (11) defines si nd, so that the sectors and the connection channels of the individual plates are congruently superimposed.

Description

Water tempered air conditioning system'With!

Condensation heat recirculation

introduction

Although air-conditioning technology has long been at a level of sophistication that, in principle, has allowed every building to be air-conditioned, complaints about the unbearable climate in office space on hot summer days have been growing lately. In particular, this is the case in old buildings in densely built-up area, where there is hardly any space for the voluminous central air conditioning systems, because neither the corresponding rooms in the basement or the attic are available, because they are already used elsewhere and no flat roofs exist where large heat exchanger to dispose of the waste heat could set up. If external facades are to be protected, no small so-called split units can be installed to cool individual rooms. For centralized regulated ventilation, the same space problem applies, because it is difficult to install in old houses the usually used air tunnel made of sheet metal. Even the traditional ventilation through open windows is not effective at high outside temperatures, especially at high humidity because then condenses on the cool from the night thick walls condensation, which enhances the discomfort of the occupants.

But even in newer buildings is cTi £ ** Lüftfauchtigkeit in the summer a problem because you would like to ventilate because of today's much larger windows and glazing but also because of the office machines, especially computers that provide a very large heat input, but at the same time the high Energy costs shy away, which one needs in order to condense all the so entrained water vapor.

The present invention therefore seeks to show a way how to achieve a relatively dry indoor air despite saving energy even in the summer when a tropical humid climate prevails outside.

State of the art

The problem of adequate air conditioning of offices in summer is currently satisfactorily solvable only in new buildings. This not only reduces the interior temperature but also regulates the humidity and ensures adequate air exchange in the rooms. There are approaches to saving energy, such as air-to-air heat exchanger to cool the incoming warm fresh air through the used but cool exhaust air during air exchange before it is cooled by highly efficient compression refrigeration to below 15 ° C, thereby containing the air To condense water vapor and eliminate the resulting water.

In order to save energy, it has been tried * * * * ^ provided for the winter heating radiators in the summer with cold well water or near the sea with cold water from deep sea layers. But this works only if this water is really very cold, because with conventional air-water heat exchangers typically temperature differences of 5-10 ° C between the cooling medium and the air temperature reached. If the cooling temperature of the air is insufficient, about 16 ° C dew point is a good value, the indoor air becomes humid and unpleasant. In any event, however, such cooling results in water condensation on the radiator, with the common problem of having to remove this water from an office room where there is no sewage pipe in the vicinity. In addition, the condensate water proves that the relative humidity of the room air comes in the vicinity of 100% in this approach, which is usually perceived as very unpleasant. The only remedy would be a heavy air change, which is why many experts recommend frequent "bump ventilation." But on hot humid days, the abundant water vapor in the outdoor air must condense there, as soon as it reaches a cooler room, especially on the walls, where then Mold is created.

Regardless, radiators for cooling or for heating the room air are usually built as air-water heat exchangers with finned tubes. These have the disadvantage that the heat on the way between inner tube and outside air a distance along

Slats must run, which have a * * * * * * * * * sweet heat resistance. This results in a significant temperature difference - as a rule, there are several degrees between the air and the liquid temperature control medium. The bigger this one

Temperature difference, however, is the worse the overall efficiency of an air conditioning system. It has therefore also been proposed to use plate heat exchangers for air-water heat exchange. But if you want to achieve very small temperature differences between water and air along the entire heat exchanger, which is the prerequisite for a recyclability of the heat, the water flow must be very small and slow. In conventional plate heat exchangers, there is the danger that there will be no water flow at all in large plate sections. In response to this problem, it has been proposed to pass the water in serpentines through a plate heat exchanger because then necessarily the same flow everywhere must prevail. The counter-argument that dominates the discussion until today, however, is that then the flow resistance of the water would be too large.

Even a controlled ventilation with air-air heat exchangers can not solve the moisture problem, because these air-to-air heat exchangers have been invented not for the summer, but for winter operation. In winter, such a heat exchanger can actually get the incoming relatively dry fresh air easily with the help of the effluent spent warm

Extract air almost to room temperature * efwaeYfhe'ft, 'Wei ·! condenses the moisture contained in the exhaust air in the heat exchanger and thus brings a much larger energy supply than the cold supply air can absorb. Although this does not solve the energy problem, it disappears from consciousness because the absolute water content of winter outdoor air is very low. After this dry air has been brought to room temperature, which can be checked with the thermometer, it has an extremely low relative humidity that deprives the human skin of water, which is subjectively perceived as cold, which is why then you set the thermostat to a higher temperature, or you evaporate water in the room to humidify the air, which also costs more energy.

Attempts have been made to circumvent the problem of condensation in the ventilation by tensioning a semi-permeable membrane between incoming air and exhaust air, which allows the water vapor to migrate from the moist heat exchanger side to the dry side. However, the efficiency of the heat exchanger drops. When such an air-to-air heat exchanger is used in summer, the cooling effect on the fresh air is low because much of the condensation takes place only in the area of cooling where the dew point of the fresh air is lowered below room temperature to provide a comfortable indoor climate , The heat input from this condensation process can not be recovered.

Overall, the calculation shows, * aas * s ** dfe2 ** relative contribution of air humidity from the air exchange to the heat balance in winter is less important than in summer.

In summer, the high outside air humidity is the biggest energy problem in the ventilation, because they are overwhelmed by conventional heat exchangers. The energy released by the condensation of water from the humid outside air is much greater than the ability to absorb heat from the exiting cool and dry indoor air. This means that an air-to-air heat exchanger can bring the indoor air to the outside temperature, but the outside air supplied changes its temperature only slightly. As soon as you deal with humid air, the heat exchanger is no longer just about heat, but about the enthalpy of this gas mixture. This requires the consideration of condensation and evaporation and their control and optimization, which is not possible in the current heat exchangers.

A further reduction in temperature and dehumidification can then be achieved only by a chiller. This asymmetry is the most important single problem for an ecologically sound climate system and its importance increases with the desired air exchange rate.

Even at an air exchange rate of LWR = 1 per hour on a hot, humid summer day, it can be seen that for a state-of-the-art air conditioning system

Water condensation is the largest single one, which is 40% of the total heat input. For an air exchange rate of LWR = 4, which is recommended in the DIN standard as the minimum value for office space, water condensation even accounts for 60% of the total heat input.

Therefore, to reduce this required cooling capacity, many authors recommend lowering the air exchange rate to LWR = 1. But then comes a new problem: In order to dissipate the large heat input from office workers, office equipment and solar radiation needs depending on the temperature of the chiller a Mindestluftstrommenge. If you choose this minimum air flow very small, the cooling temperature must be very low. Leading chiller manufacturers recommend 7 ° C. The air-conditioned room creates an inhomogeneous air mixture with very different temperatures, which leads to frequent illnesses of the users of such a room.

Objects of the invention

The object of the invention is to provide a device to solve the problems that occur but preferably not exclusively in the subsequent installation of an air conditioner in old buildings in city centers, which are - A generous air change should not lead to high humidity in the interior. - The water condensation from def * sdhdtri: t should not add any additional heat into the system - The humidity in the interior should always be in the comfort range - The system should not generate noise - The device should not have any elements that are visually disturbing to the External facade or on the roof must be mounted. - The system should consist of coupled individual modules that autonomously regulate the climate for a small part of the building. - The system should use cold water in summer, preferably well water, or water from geothermal heat exchangers or other natural sources of cold. In winter, then from the same water with a heat pump warm heating water can be made solution of the task

From the requirement profile it follows that the device according to the invention must consist of a combination of heat exchangers. There are 3 tasks to be separated: - The entire condensed water when cooling the moist fresh air must be evaporated from the exhaust air during their warm-up process in the air-to-air heat exchanger again. - Following the pre-cooling phase in the, * ldf> t "air heat exchanger, the subsequent cooling and dew point cooling of the pre-cooled supply air must be carried out to a desired dew point with concomitant collection of condensate and introduction into the exhaust air for evaporation in the pre-cooler - The actual room cooling, which is independent of the ventilation, should be carried out with high air flow but small temperature spread, in order to avoid the dreaded cold drafts.

These three action areas are to be brought together in a compact device. Since all of these objects can be achieved by specially shaped countercurrent plate heat exchangers, the shape of which will be described below, the apparatus should consist of a stack of plates, where on each plate an area is allocated for each of the three tasks, these areas being assembled Plate stacks are largely congruent. Instead of the usual connecting pipes or elements between different heat exchangers only webs are applied to the tops of the plates, which direct the air or water flows as intended. These webs may be press-fitted or glued or soldered to the plates in the case of using metal plates. Are the plates made of plastic so it is advantageous to manufacture plates and bars in one piece. The plates are mounted horizontally on top of each other and connected with each other via the ** St * d ^ d * di ^ hl *. It follows, of course, that you could also attach webs on the undersides of the plates or on both sides.

The first heat exchanger, which serves to pre-cool the moist warm supply air through the cool, low-humidity exhaust air, is based on the principle that the cooling supply air loses part of its water through condensation as it passes through the counter-flow-fed plate heat exchanger. This condensed water is entrained in the narrow gaps of the heat exchanger and collected at the interior-side outlet in a special condensate trap of the heat exchanger in the form of a groove with one or more holes and passed to the immediately below the inlet for the cool spent room air and distributed in the plate columns. The warming exhaust air now tears this water with it through the heat exchanger and evaporates the water again. For this evaporation process to be carried out completely, it is necessary that the air and water mix closely. This is achieved in that the heat exchanger plates are indeed provided with a smooth surface, but have waves transverse to the flow direction, whereby each two superimposed plates in the troughs Siphone form, in which collect water droplets, which, because they impede the flow of air from the latter be pushed further.

In addition, this condensate recirculation can be used to introduce additional water into the exhaust air flow, whether it be condensation water from the second heat exchanger, be it water from an external source, so that the first heat exchanger will even function as true evaporative cooling.

In order to be suitable for winter operation, the condensate bypasses are also attached to the inlet end of the heat exchanger, because in winter the exhaust air is moist and condensation forms, while the supply air is dry and must be moistened in the heat exchanger to prevent the indoor air becomes too dry and then consuming energy needs to be moistened.

The second heat exchanger cools the fresh air pre-cooled in the first heat exchanger up to an adjustable dew point. It is a special counter-current charged air-water heat exchanger with double plates through which water flows. In contrast to the conventional finned tube air-water heat exchangers, the difference in temperature between air and water can be made almost arbitrarily small by double plates whose interspace is exposed to water, especially when the air flow is being directed between smooth flat plates, and the water flow not according to the prior art combined with straight flow direction

Verwirbelungselementen but on the top of the plate in a smooth flow-favorable Ausffffllgfjlg * * r * * I is limited by webs between two plates serpentine guided. The argument that then the water flow resistance becomes too large can be invalidated as follows: The faster the water moves, the higher the heat transfer coefficient to the heat exchanger wall. This requires a smaller heat exchanger surface and the path length of the water flow can be reduced. Through experiments and accurate calculation, one can prove that there is an optimal range for this process if the water flow has a Reynolds number that is about 10-50% higher than the critical Reynolds number. The Wassererpentinen must therefore only be dimensioned accordingly, so that the amount of water required for the application with these serpentine dimensions in the specified

Reynolds number range is. Through a control valve, the amount of cooling water can then be precisely dosed within this optimum range, whereby an accurate adjustment of the cooling temperature of the fresh air and thus the optimum dew point of the room air is achieved. In addition, this heat exchanger also has a condensate trap and a built-between two plate webs on each of the air conducting plates water pipe to the corresponding plate on the first heat exchanger to evaporate the condensate there.

The third heat exchanger's job is to heat the heat in the room, not by the

Ventilation caused to ffeiurtftäli Stireren. Since this task is no longer concerned with achieving a low dew point, it is intended to avoid hypothermia of the air, so that the comfort zone is not left. Since the temperature spread is therefore small, the air flow in this heat exchanger must be significantly greater than in the first two heat exchangers. The third heat exchanger should also be a counter-current charged air-water heat exchanger with water-flow plates, in an analogous construction to the second heat exchanger, but with other dimensions that result from the other flow rates and also without condensate trap. For cooling, the coming from the second heat exchanger and from there already slightly warmed cooling water can be used, since the average air temperature in the third heat exchanger will always be a few degrees above the mean air temperature in the second heat exchanger. In addition, however, a control valve is provided, through which the cooling water before entering the third heat exchanger still a variable amount of very cold cooling water can be added.

Effects and sub-effects of the invention

The separation of the air conditioning process into three action areas has the purpose of being able to individually regulate and optimize the associated tasks, because temperature, humidity, airflow and

Energy consumption otherwise * strongly influence each other

The design of the device as a plate stack allows a simple and cost-effective production because there are no pipe connections or branches between the heat exchangers. Instead of those otherwise usual pipes only ridges are attached to the plates, which direct the air or water flows as intended.

The first heat exchanger evaporates on the heating side as much water as condenses on the cooling side in the first and in the second heat exchanger. Thus, the performance of the two heat exchanger sides corresponds to each other and the supply air has after leaving the first heat exchanger already a temperature below the room air. The condensate collectors at both ends of the heat exchanger allow an energetically favorable air exchange even in winter.

By supplying additional water into the exhaust side of the heat exchanger, it can also function as an evaporative cooler.

The second heat exchanger allows to cool the supply air with very small amounts of water flow. The water side is not in the state of the art with a straight flow combined with swirling elements but in a smooth aerodynamic design in

Serpentine shape, because by increasing the flow velocity over the critical Reynolds number a significantly higher heat transmission coefficient is achieved. As a result, the necessary active area of the heat exchanger is reduced so much that the increased by the increased flow velocity friction resistance is compensated.

By controlling the amount of water flow, the desired air temperature can be precisely set, and thus the dew point of the room air.

The third heat exchanger allows the flow rate and the room temperature to be set independently of the dew point regulation of the second heat exchanger.

Aufzählung of the pictures:

Fig.l shows the system consisting of three connected plate heat exchangers, wherein Luftumlenkungsbleche, fans and control elements have been omitted

Fig. 2 shows the flow scheme of the air and water flows of the system

3 shows 2 corresponding plates from the first heat exchanger

4 shows 2 corresponding plates from the second heat exchanger

FIG. 5a shows a plan view of an * L * uPtf> * ia * tte * 'of the connected heat exchanger system

Fig. 5b shows a plan view of a water plate of the connected heat exchanger system

Fig. 6 shows 2 corresponding plates of the connected heat exchanger system

The letters and numbers in the figures mean: VI, V2 ... Water flow controls V3, V4 ... Air flow controls A. .. first heat exchanger, pre-cooling B. ..second heat exchanger, dew point adjustment C. ..third heat exchanger, main cooling 1 .. . Exhaust air la. .. Supply of exhaust air from the interior to the cooling system lb. .. Part of the exhaust air to be cooled in the third heat exchanger lc. .. Return of the partial flow lb into the conditioned space ld. .. Partial flow of the exhaust air, which should be replaced with fresh air 2 ... Fresh air ström 2a ... Fresh air flow on the way through * the **

Pre-cooler heat exchanger 2b ... Fresh air flow on the way through the dew point reduction 2c ... Supply of fresh air into the conditioned space 3 .. .Kühlwasser ström 3a ... Cooling water supply to the system 3b ... Cooling water flow through the second heat exchanger 3c ... Connecting line of the cooling water flow from the second to the third heat exchanger 3d ... Additional cooling water for the third heat exchanger 4a ... Condensation water recirculation in the first heat exchanger for summer operation 4b ... Condensation water recirculation from the second heat exchanger to the first heat exchanger 4c ... external water supply to the first heat exchanger 4d. .. Condensation water recirculation in the first heat exchanger for winter operation 5,6,7,8 fans or blower 9 ... Air plate lCL.Water plate 11 .. .5.eg lla ... ring-shaped bar 12 .. Tray as condensate trap 12a..Verdampferrinnen 13 ... air-conditioned interior

Description of the drawings

Fig.l shows the system consisting of three connected plate heat exchangers, wherein cover plates, Luftumlenkungsbleche, fans and control elements have been omitted. This plate heat exchanger system consists of a block of horizontal congruent plates, of which there are two types -9,10- which alternate regularly. All plates are made of smooth material which has at the top webs -11-. The top plate under the cover plate, not shown, is a so-called air plate -9-, because on this plate, the air cooling with condensation takes place, the next element underneath is a so-called water plate -10- because on this plate in the two heat exchangers -B and -C- moves the cooling water. Only in the heat exchanger -A-flows over the plate 10 of the exhaust air -ld-. Next comes another air plate -9- and then another water plate -10- and so on. The bottom plate is a water plate -10-.

In the figure you can see directly on the inside of the heat exchanger plate, an air plate -9-, on which fresh air -2- flows laterally into the first heat exchanger -A-. On this plate -9-the air -2a cools down and if it falls below the dew point, condensate forms, which is pushed from the air -2a to the condensate trap -12-. The Kondensatfänger -12- consists of a pronounced upward to concave groove transverse to the flow direction with one or more holes -4a-through which the condensed water drips to the underlying plate -10- where it is evaporated and absorbed by the exhaust air -ld-again , This exhaust air flow -ld- leaves the heat exchanger -A-side next to the fresh air supply -2-. After the first heat exchanger -A-, the fresh air -2a, 2b- is led to the second heat exchanger -B-. Immediately below this plate -9- is the water plate -10- where in the case of the second heat exchanger -B- in the summer cold water, in the winter hot water from below the plate -9- tempered, causing more condensation in the summer from the air stream - 2b-, which is conveyed to the condensate trap -12- of the heat exchanger -B- and then dripped through the channel -4b- back to the first heat exchanger -A- guided through the hole at -4c- on the underlying plate -10- where it merges with the airstream -ld-. If, in addition, water is introduced from the outside -4c into the first heat exchanger -A- from the outside, then this can provide an additional

Evaporative cooling can be achieved. The temperature of the air-conditioned interior is given in the third heat exchanger -C-, where a part of the exhaust air flow -lb- from the cooling or heating water -3b- and -3d- is brought to the desired temperature becomes. These two streams leave the third heat exchanger C together at the -3f- exit.

Fig. 2 shows the flow scheme of the air and water flows of the system. It is assumed that the system to be ventilated -13- up to the exhaust air flow -ld and the fresh air flow -2- has no further significant air changes with the environment, so that the mass flows -ld- and -2- are the same. By appropriate adjustment of the 4 fans - 5, 6, 7, 8 - the latter condition can always be achieved, even if the room to be conditioned should have -13-leaks. The following functional description refers to the summer, but is almost identical to the function in winter, with the difference that in winter no cooling water, but heating water is used.

The fresh air -2- enters the first heat exchanger -A-, and cools down there -2a- because it flows in countercurrent to the outgoing exhaust air -ld. If it falls below the dew point of the air -2b, condensate -4a is formed, which is supplied from the interior -13- coming relatively dry air -ld-, which heats up in the heat exchanger -A- and thereby the condensation - 4a - evaporated. If more or equal water condenses on the exhaust air side of the heat exchanger -A- than condenses on the fresh air side, the temperature decrease in the air flow -2a must be greater than or equal to the temperature increase in the air flow -ld- , If the fresh air -2- was sufficiently moist outdoors, then it has -2- after leaving the first heat exchanger -A- about its dew point temperature, which means it has 100% relative humidity. After the first heat exchanger -A-, the fresh air -2a is therefore directed into the second heat exchanger -B-, where this air -2b- is further cooled because it moves in countercurrent to the cold water flow -3b-. The temperature of -2b- simultaneously with the dew point and further water -4b- condenses, which is also to the exhaust air -ld- in the first heat exchanger -A-guided and evaporated there, which enhances the cooling effect of the heat exchanger -A-. In addition, provided that the outside air is not very humid, -2- external water -4c can also be introduced through the same duct into the exhaust air flow -ld- in parallel with the condensate -4b-, providing additional cooling.

The cooling of the air-conditioned interior -13- does not take place exclusively via the cooling of the fresh air -2-, but separated from the ventilation via a recirculation system. Coming from the room -13- the exhaust air flow -la- is first divided by the control element -V3-in the two air streams -lb- and -ld- and the current -b- in the third heat exchanger -C- out.

There it flows in countercurrent to the cooling water, which is composed on the one hand of the current -3c coming from the second heat exchanger -B- and on the other hand of the partial flow -3d- branched off from the main cooling water flow -3a. The volume control of the two partial streams via the control elements -Vl- and -V2-.Sobald this cooling water has warmed in the heat exchanger -C-, it leaves the system in a single line -3f-. As soon as the cooled air stream leaves the heat exchanger -C- it unites in the control element V4 with the fresh air -2c- and flows as fully regenerated air with optimum temperature and humidity back into the room -13-. For the functioning of the condensation water return, it is important that the difference in air pressure between the supply air and exhaust air in the heat exchanger -A- always moves the water in the direction that it flows from the condensation to the evaporation. In the summer condensation takes place in the fresh air -2a- and the evaporation in the exhaust air -ld- and the condensed water passes via the path -4a from the fresh air side to the exhaust side. In winter, on the other hand, the condensation takes place in the exhaust air -ld- and the evaporation in the fresh air -2a- and the condensed water passes through the path -4d- from the exhaust side to the fresh air side. These required pressure differences can be achieved by controlling the 4 fans -5,6,7,8- and the regulator -V3, four-rich.

Fig. 3 shows two corresponding pillars * e from the first heat exchanger -A- with webs -11- at the edges, which guarantee when joining the plates that stay free between the plates columns and these columns are closed to the outside. Inflows of exhaust air and fresh air -ld, 2a- and their outflows -ld, 2b- can only take place at the points where no webs -11- are attached.

The upper plate element is part of the so-called air plate -9-, the lower element is part of the so-called water plate -10-. Over the upper plate -9-flows the fresh air flow -2a-, over the lower plate -10- the exhaust air flow -ld-. Both plates have gentle waves -12a transverse to the flow direction of the air. This ensures that condensate collects in the troughs, especially in the condensate traps -12- which are nothing more than particularly pronounced deeper grooves than the troughs -12a- and from there through the holes at -4a- in summer or -4d- in the winter to the neighboring plate, where by the waves -12a an intimate contact between this water and the flowing air is forced, which is a prerequisite for the subsequent evaporation. At the entry hole -4b (4c) - additional condensate -4b- from the second heat exchanger -B- or external water -4c- can be introduced into the evaporation. The same processes as in the plate pair -9,10- drawn in this illustration repeat themselves for all others

Plate pairs -9,10- throughout the heat exchanger block plate -A-.

Figure 4 shows two corresponding plates -9, 10- from the second heat exchanger -B- with webs -11- at the edges, which assure, when assembling the plates, that gaps remain between the plates and these gaps are closed to the outside but also to guide the water streams -3b, 3c and -4b-. The upper plate element is part of the so-called air plate -9-, the lower element is part of the so-called water plate -10-. Both plates have, on the picture from left to right, a gentle slope that ends up in a kink, the on the plate -9- serves as a condensate trap -12-, from where the condensate in the channel -4b- is passed, which brings it to the adjacent heat exchanger -A-. The cooling water -3a flows through a hole surrounded by an annular ridge -11a on the plate -9- to the next lower plate -10- where there is no ridge around the corresponding hole, so that a cooling water flow -3b branches off and along which passes through further webs -11-serpentine to the other end of the plate, where it opens into the channel -3c- which leads him to the next cooling zone -3e- in the third heat exchanger -C-. The same processes as in the plate pair -9,10- drawn in this figure are repeated for all other plate pairs -9,10- in the gah * 2e * fl heat exchanger plate block -B-.

5a shows a plan view of an air plate -9-of the connected heat exchanger system -Ά, B, C- to show how the webs -11- on the one hand the air streams -2a, 2b- and -lb- separate from each other, and on the other hand, the condensate -4b- formed in the second heat exchanger -B- lead into the transfer hole -4b (4c) of the first heat exchanger -A-. In addition, it can be seen that the water connection holes for the cooling water sections -3b, 3d, 3f- on the plate -9- are surrounded by an annular ridge -11a.

Fig. 5b shows a plan view of a water plate -10- of the connected heat exchanger system -A, B, C- to show how the webs -11- on the one hand the exhaust air flow -ld- in the first heat exchanger -A- from the cooling water-carrying streams -3b, 3c, 3d, 3e, 3f- in the heat exchangers -B- and -C- separate and how these webs define the serpentines -11- for the cooling surfaces -3b and -3e-. In particular, it can be seen how the duct -3c directs the cooling water flow -3c- from the left end of the heat exchanger -B- to the inlet of the heat exchanger -C- on its right side, where it branches off with the partial flow diverted from the main cooling water duct 3a -3d- combined to temper with this together as a combined cooling water stream -3e- the main air cooler -C-.

As already noted in FIGS. 3 and 4, the same operations of the drawn one are repeated

Plate pairs -9, 10- as in the description of £> hdfi figures Fig. 5a and Fig. 5b for all other pairs of plates -9,10- in the whole heat exchanger plate block -C-.

Fig. 6 shows two corresponding plates -9, 10- of the connected heat exchanger system -A, B, C-. In particular, the condensate transitions -4a, 4b and -4c between the plates -9- and -10- can be seen. The condensate of the plate -9- in the first heat exchanger -A- during summer operation collects in the condensate collector -12- and flows through the hole at -4a- from the plate -9- to plate -10-, where the water is through the air flow -ld- transported over the troughs -12a-because they form a siphon in conjunction with the in-heat exchanger -A- also corrugated plate -9- and the gap between the two -9,10- located where each so much condensation until a part of it is entrained by the air flow -ld-and lands in the adjacent wave trough -12a, where due to the fresh air flow with water condensation -2a on the overlying plate -9- there is a higher temperature than in the previous wave trough -12a Therefore, even in the new warmer wave trough, water is vaporized, even though the air flow -ld- in the previous trough -12a-may have already been saturated with moisture. In addition to the condensate -4a from the heat exchanger -A-comes in summer mode via the line -4b-condensate from the plate -9- of the heat exchanger -B-in the heat exchanger -A- on the plate -10-. At the

In winter there is no condensation * Attf #dier »* plate -9- but for the air from the exhaust air -ld-relatively damp, so that condensate on the plate -10- forms in the heat exchanger -A-.

This condensate -4d- collects in the condensate collector -12- of the plate -10- and passes through the hole located there to the next lower plate -4d / 9-

Claims (6)

claims 1. Air-to-air plate heat exchanger (A) according to the countercurrent principle, consisting of two different plate types (9,10), characterized in that the plates (9,10) are stacked in a mainly horizontal position alternately stacked, the plates on the flow parallel Outer edges webs (11) or spacers have, by which the plates are firmly and tightly connected to each other in such a way that between them a narrow gap remains open, wherein the plates (9,10) have a smooth surface and are curved wavy, so that the wave troughs (12a) are transverse to the flow direction of the air and where the last wave crests on both heat exchanger ends are bent much higher than the other wave crests, so that in the direction of the heat exchanger interior in the air flow direction to the outside a Kondensatabscheider (12) in the form of a particularly pronounced Wellentals arises in the valley floor, one or more holes (4a, 4d) are located by the condensation on the underlying plate can and where wave troughs (12a) of one plate type (9) with troughs (12a) of the other plate type (10) come to lie exactly above each other and the wave amplitude is greater than the plate spacing. 2. Air-to-air plate heat exchanger (A) according to claim 1, characterized in that in each inflow of the colder of the two heat exchangers (A) impinging air flows *** fId * ^ a ") * e2UiДzlich to this air small amounts of water are introduced, which are vaporized on the way this in the heat exchanger (A) warming cold air. 3. Air-to-air plate heat exchanger (A) according to claim 2, characterized in that the introduced from the outside into the heat exchanger (A) water is the condensation of a cooling system. 4. Air-water plate heat exchanger (C) according to the countercurrent principle, consisting of two different plate types (9,10), characterized in that the plates are stacked in a mainly horizontal position alternately stacked, the plates at the flow-parallel outer edges webs (11) or spacers by which the plates are firmly and tightly connected to each other in such a way that a narrow gap remains open between them, the plates (9, 10) having a smooth surface and being substantially flat, and where on the air plates (9 ) the air stream (2b) is free to move from one end of the heat exchanger to the other along the water plates (10), while on the water plates (10) the webs (11), in addition to the air flow parallel outer edges on the plate inner surface, define serpentines through the water in a manner that the main flow direction is opposite to the air flow direction and the flow velocity indentity, which is defined by the flow cross-section, is chosen so that its Reynolds number is 10-5 ^ l ** ut5e * r * ider * critical Reynolds number. 5. Air-water plate heat exchanger (B) according to claim 4, characterized in that in the direction of the heat exchanger interior in the direction of air flow to the outside a slight slope at the end of the plates are bent high, creating a Kondensatabscheider (12) in the form of a valley transverse to Air flow direction is formed, from which condensate between webs (11) for further use as in claim 2 or 3 is led away. 6. air conditioning system consisting of 3 plate heat exchangers, 4 fans or blowers and 4 control elements and external cold or hot water supply, characterized in that the first heat exchanger (A), a heat exchanger according to claim 3, the second heat exchanger (B), a heat exchanger according to claim 5 and the third heat exchanger (C) is a heat exchanger according to claim 4, wherein these three heat exchangers are integrated in a system that they form a single plate block with substantially horizontal plates, where on each plate each of the three heat exchangers involved a sector and between these sectors connecting channels are assigned and are defined by webs, so that the sectors and the connection channels of the individual plates are congruent to each other.