HEAT EXCHANGER DEVICE AND METHOD FOR EXCHANGING HEAT BETWEEN AIR AND A FLUID CARRIED IN A HEAT EXCHANGER

Description

[0001] The invention relates to a heat exchanger device for exchanging heat between air and a fluid guided in at least one heat exchanger according to the preamble of claim 1 and to a method for exchanging heat between air and a fluid guided in a heat exchanger according to the preamble of claim 14.

[0002] Such heat exchange devices can be used, for example, as evaporators in refrigeration machines or cooling systems in which air drawn in from the environment is cooled, or in heat pumps.

[0003] In particular, such heat exchanger devices can be used in air coolers to cool the air in large-volume rooms, such as walk-in storage or cold rooms. The air coolers used for this purpose are part of the equipment of the storage or cold room and are installed stationary therein. The air cooler contains a heat exchanger, e.g. in the form of a heat exchanger, past or through which the air to be cooled is passed, whereby the heat exchanger extracts heat from the air and cools it down. The heat exchanger can be a heat exchanger that has a pipe or duct system through which a coolant or refrigerant flows. The heat exchanger can also be an evaporator that has a pipe or duct system through which a two-phase refrigerant flows. The pipe or duct system of the evaporator is connected to a compressor and a condenser orcoupled to a dry cooler, which is usually located outside the space to be cooled (e.g., on the roof of the building in which the storage or cold room is located). The condenser or dry cooler is connected to the evaporator of the air cooler via pipes to conduct the refrigerant in liquid state and under low pressure through the evaporator. As the air in the storage or cold room to be cooled flows through the evaporator, the initially liquid refrigerant evaporates, removing heat from the flowing air. The evaporated refrigerant is returned via the pipe to the compressor and the condenser or dry cooler, where it is liquefied or cooled by compression.

[0004] EP 836 057 B1, for example, discloses a refrigeration machine designed as a dual-flow evaporator with a housing having a plurality of air inlet openings arranged at a distance from one another in the longitudinal direction of the housing and two air outlet openings. The air inlet openings are arranged substantially in a horizontal plane and the two air outlet openings are arranged substantially in a vertical plane. A fan is arranged in each of the air inlet openings, and each air outlet opening is assigned a heat exchanger, each of which has a circuit for circulating a cooling or heat transfer fluid.The fans arranged in the air inlet openings suck in air from the environment and pass it through the heat exchangers, whereby a heat exchange takes place between the sucked in air and the cooling or heat transfer fluid circulating in the heat exchangers, which leads to a cooling of the sucked in air and the evaporation of the fluid in the heat exchangers.

[0005] The problem with these types of heat exchangers is that the air drawn in flows unevenly across the cross-section of the heat exchanger, resulting in different flow densities and flow velocities. The heat exchangers therefore have areas with varying heat transfer and heat exchange efficiencies. Since no refrigerant in liquid form may be introduced into the compressor downstream of the heat exchanger, superheating generally occurs in the heat exchanger to ensure that the refrigerant in the heat exchanger has completely evaporated before it is fed to the compressor. During operation, the heat exchanger is controlled so that only as much refrigerant is fed to the heat exchanger as it can completely evaporate.It is known for the pipes of a heat exchanger, in which the refrigerant is carried, to be supplied with the liquid refrigerant strand by strand, with the refrigerant flowing through the individual pipe strands parallel to one another. If different areas of the heat exchanger have different heat transfer or heat exchange efficiencies, the strand with the lowest heat transfer or heat exchange efficiency determines the maximum amount of refrigerant that is supplied to the strands per unit of time so that complete evaporation of the refrigerant in all strands can be ensured. In some areas in the strands with higher heat transfer or heat exchange efficiency, this can lead to premature evaporation of the fluid carried in the heat exchanger and thus to a reduction in the efficiency of the heat exchanger device, because the areas or strands of the heat exchanger with higher heat transfer or heat exchange efficienciesHeat exchange efficiency cannot be operated under optimal operating conditions.

[0006] In EP 2 759 795 A2, the arrangement of at least one flow-guiding device in a region outside the cross-section of the heat exchanger subjected to flow is proposed to even out the flow through the heat exchangers of a heat exchanger device, wherein the flow-guiding device influences the flow of air flowing through the heat exchanger in the edge regions of the heat exchanger. In particular, the arrangement of flow-guiding devices outside the cross-section of the heat exchanger subjected to flow ensures that sufficient air also flows through the (upper) edge region of the heat exchanger. The flow-guiding devices ensure, in particular, that air flowing along the ceiling of the housing of the heat exchanger device is directed to the upper edge regions of the heat exchangers.

[0007] From JP 08200722 A an air conditioning device for installation on a floor of a room is known, in which a heat exchanger and a fan designed as a radial fan, which sucks air from the room through an inlet opening and directs it in a radial direction onto a flow surface of the heat exchanger, are arranged in a housing, wherein the air flow flowing through the heat exchanger flows out of the housing into the room through an outlet opening and air guide elements are assigned to the heat exchanger, which are arranged within the cross-section of the flow surface of the heat exchanger and divide the air flow into several partial flows and redirect it in the direction of the heat exchanger.

[0008] Another approach to avoiding efficiency losses caused by uneven air flow through the heat exchangers is proposed in EP 2 365 271 A2. This proposes an air-charged evaporator, which can be used in particular in an air-water heat pump. The evaporator comprises at least two refrigerant lines that can be charged with air, with a first refrigerant line running in a first evaporator region and a second refrigerant line running in a second evaporator region. Due to uneven air flow through the refrigerant lines, which serve as heat exchangers between the charged air and a fluid carried in the refrigerant lines, the air flow velocity in the first region during operation of the evaporator is higher than in the second region.As a result, the refrigerant lines in the first and second regions have different heat transfer efficiencies, which can lead to overheating of the fluid conveyed in the refrigerant lines in the region with the higher heat transfer efficiency. To avoid this, the refrigerant lines are designed differently from one another or can be adapted to one another, so that the heat transfer or evaporation efficiency (evaporation effectiveness) in the refrigerant line, which is subject to a lower air flow velocity, is greater than in the other refrigerant line. This can increase the efficiency of the evaporator. To adjust the different evaporation efficiencies in the two or more refrigerant lines, controllable pressure reducing means are preferably provided in at least one refrigerant line, and the evaporator comprises measuring devices for measuring the operationally relevant parameters, such asthe flow velocity of the air flowing past the refrigerant lines, as well as the pressure and temperature of the fluid conveyed in the refrigerant lines. The placement of pressure-reducing devices in the refrigerant lines leads to a pressure loss of the fluid flowing in the refrigerant lines and thus to a reduction in efficiency. The placement of measuring devices in the evaporator is complex and expensive and requires high maintenance.

[0009] Based on this, the invention is based on the object of providing a heat exchanger device that is as simple and cost-effective to manufacture as possible and has the highest possible efficiency. In particular, in a heat exchanger device with at least one heat exchanger comprising several different pipeline strands, the aim is to achieve a homogenization of the heat transfer in the individual strands.

[0010] These objects are achieved with a heat exchanger device having the features of claim 1 and with the method according to claim 14. Preferred embodiments of the heat exchanger device and the method can be found in the dependent claims.

[0011] The heat exchanger device according to the invention comprises a housing with at least one inlet and at least one outlet, and at least one heat exchanger arranged within the housing, in which a fluid, for example, a coolant or refrigerant, is conveyed. The or each heat exchanger arranged in the housing comprises a plurality of pipes grouped in strands and has an inflow surface against which air, for example, drawn in from the environment, can flow.In order to equalize the air flow flowing towards the heat exchanger, in particular with regard to the air flow velocity across the cross-section of the inflow surface, at least one air guide element is assigned to the or each heat exchanger in the heat exchanger device according to the invention, which air guide element is arranged within the cross-section of the inflow surface of the respective heat exchanger and divides the air flow flowing in through the inflow opening into at least two partial flows, wherein at least one of the partial flows is deflected in the direction of the respective heat exchanger by the or one air guide element.

[0012] By dividing the air flow entering the heat exchanger device through the inlet opening of the housing into at least two partial flows, the flow velocity or flow density of the air flowing toward the inflow surface of the or each heat exchanger is made more uniform. The partial flows preferably impinge on the inflow surface of the heat exchanger at different locations or in different areas of the inflow cross-section.

[0013] The or each air guiding element assigned to a heat exchanger is preferably arranged within the cross-section of the inflow surface of the respective heat exchanger in such a way that the total amount of air flowing in through the inflow opening of the housing is evenly divided into two or more partial flows, each with the same or at least a similar flow density (or flow velocity). The or each air guiding element assigned to a heat exchanger is expediently shaped in such a way that at least one partial flow is deflected in the direction of the inflow surface of the respective heat exchanger. Expediently, at least one partial flow is deflected by the air guiding element or the air guiding elements in such a way that this partial flow flows at least substantially perpendicularly towards the inflow surface of the heat exchanger. The other partial flow or flows can be deflected by further deflection devices, e.g.from wall sections of the housing, towards the inflow surface of the heat exchanger.

[0014] In one embodiment, the housing of the heat exchanger device according to the invention is box-shaped and has an upper wall designed as a cover, a lower wall designed as a base, and side walls arranged between them and perpendicular thereto, wherein the or each inlet opening is arranged in the lower wall and the or each outlet opening is arranged in a side wall. The housing can, for example, be fastened to the ceiling of a room with the upper wall designed as a cover. A fan is expediently arranged in each inlet opening, which sucks air from the room and guides it into the interior of the housing. The or each fan is preferably designed as an axial fan. A heat exchanger, for example in the form of a heat exchanger, in particular an evaporator, is arranged in each outlet opening.Each heat exchanger is assigned at least one air guide element, located within the cross-section of the inflow surface of the respective heat exchanger. The air drawn in by a fan is divided into two or more partial flows by the air guide element(s), and at least one of the partial flows is deflected by an air guide element toward the respective heat exchanger. The partial flows flow through the respective heat exchanger, exchanging heat with the fluid conveyed in the heat exchanger, and finally out of the housing through the outlet opening assigned to the respective heat exchanger.

[0015] In a practical embodiment, the heat exchanger device comprises two heat exchangers arranged opposite one another in the side walls of the housing. Depending on the required output of the heat exchanger device, this comprises a plurality of inlet openings arranged one behind the other in the longitudinal direction and at a distance from one another, in each of which a fan is arranged. Each fan is expediently arranged in a nozzle. For this purpose, each inlet opening is surrounded by a nozzle ring protruding into the interior of the housing, and the fan is arranged at least partially within the nozzle ring. In particular, the rotor blades of the fan engage at least partially in the nozzle ring. Preferably, the or each fan is an axial fan, which is expediently arranged at least partially outside the cross-section (Q) of the heat exchanger subject to flow.

[0016] An improvement in the onflow of the air sucked in through the or each inlet opening and a deflection of the partial flows onto the inflow surface of the heat exchangers arranged in the housing can be achieved if the upper wall of the housing, which is opposite the or each inflow opening, has an outer section and an adjoining inner section, wherein the outer section borders (expediently on both sides) on a heat exchanger and delimits the cross-section of the inflow surface of this heat exchanger, and the inner section has a projection protruding into the interior of the housing in the direction of the inflow opening opposite the outer section, wherein a fan is attached to the projection. In particular, a rotary shaft of the fan is rotatably attached to the projection.

[0017] The projection protruding into the interior of the housing in this embodiment can, for example, be formed by a sheet metal with a trapezoidal cross-section, which is attached to the upper wall of the housing. This geometry achieves a deflection of the upper partial flow(s) toward the inflow surface of the heat exchanger.

[0018] The transition between the projection and the outer section of the upper wall can be formed, for example, by a curved wall section or by a wall section running at an obtuse angle to the outer section.

[0019] The or each air guide element assigned to a heat exchanger can, for example, be plate- or strip-shaped, in particular in the form of an air guide plate which extends within the cross-section of the inflow surface of the assigned heat exchanger in the longitudinal direction of the heat exchanger device and at least substantially parallel to the upper or lower wall of the housing. To deflect the lower partial flow formed by the respective air guide element towards the inflow surface of the respectively assigned heat exchanger, the or each air guide element is expediently bent downwards or angled downwards at the edges. It is particularly expedient if the or each air guide element is concavely curved on its underside, which faces the lower wall of the housing, or if the edge regions of the air guide element are bent at an angle to the lower wall of the housing.This allows a directed deflection of the lower partial flow towards the lower, bottom-side area of the inflow surface of the respective heat exchanger.

[0020] The position of the or each air guide element relative to the lower wall of the housing is conveniently adjustable, for example, by pivoting the air guide element. By adjusting the position of the air guide element relative to the lower wall of the housing or the inflow area of the associated heat exchanger, both the air volume in the individual partial flows and the flow direction of the partial flows can be changed and adapted to requirements.

[0021] In order to minimize flow losses, it is expedient if the or each air guide element is streamlined, for example in the shape of an airfoil. Particularly in heat exchanger devices with comparatively tall heat exchangers in which several strands of pipes are arranged one above the other, it is possible to assign more than one air guide element to each heat exchanger, wherein the several air guide elements are arranged one above the other and at a distance from one another within the flow cross-section of the heat exchanger. In this way, the air flowing in through an inlet opening is divided into more than two partial flows, as a result of which the quantity or flow density of the individual partial flows can be evened out across the cross-section of the heat exchanger. In this way, each area of the heat exchanger or each strand of pipes in the heat exchanger is supplied with air evenly, so that in each area orThe same heat transfer efficiency prevails in each strand of the heat exchanger. This prevents overheating of the fluid in individual strands of the heat exchanger, thereby improving the efficiency of the heat exchanger system.

[0022] These and other advantages and features of the invention will become apparent from the following detailed description of the embodiments with reference to the accompanying drawings, in which: Figure 1: Perspective view of a first embodiment of a heat exchanger device according to the invention; Figure 2: Detailed view of the interior of the heat exchanger device of Figure 1 ; Figure 3: Cross section through the heat exchanger device of Figure 1 ; Figure 4: Detailed view of the interior of the heat exchanger device of Figure 1 in a perspective view from below; Figure 5:Top view of the heat exchanger device of Figure 1 with the housing cover removed; Figure 6: Schematic representation of further embodiments of heat exchanger devices according to the invention; Figure 7: Schematic representation of further embodiments of heat exchanger devices according to the invention; Figure 8: Schematic representation of further embodiments of heat exchanger devices according to the invention; Figure 9: Schematic representation of an embodiment of a heat exchanger device according to the invention with two heat exchangers, each containing a plurality of pipes grouped in strands;

[0023] In the Figures 1 - 5 a first embodiment of a heat exchanger device according to the invention with two heat exchangers 1a, 1b arranged in a housing 2 is shown, wherein the Figures 2 - 5 show a view of the interior of the housing 2. For a better illustration, the Figures 2and 3 a front side wall, in Figure 4 a front side wall and a bottom wall and in Figure 5 an upper wall of the housing is removed to provide a view into the interior of the housing 2.

[0024] The two heat exchangers 1a, 1b are arranged in the housing 2 mirror-symmetrically to the central longitudinal plane of the housing 2 and parallel to each other as well as spaced apart from each other. Each heat exchanger 1a, 1b consists of three heat exchanger blocks 1, 1', 1" arranged one behind the other in the longitudinal direction L of the heat exchanger device, as can be seen from Figure 1visible. Each heat exchanger block 1, 1', 1" is arranged in an outflow opening 4, 4', 4" of the housing 2. When reference is made below to a heat exchanger 1, this refers to a heat exchanger 1a or 1b or both heat exchangers 1a, 1b, and when reference is made to an outflow opening 4, this refers to an outflow opening 4, 4', 4" in which a heat exchanger block 1, 1', 1" is arranged.

[0025] As from Figure 1As can be seen, the housing 2 is box-shaped and comprises an upper wall 2a designed as a cover, a lower wall 2b designed as a base, and side walls 2c arranged between them and perpendicular to the latter. The outflow openings 4 with the heat exchangers 1 inserted therein are arranged in the two longitudinal side walls 2c. In the lower wall 2b, several (three in the embodiment shown) inlet openings 3 are provided one behind the other in the longitudinal direction L and at a distance from one another. A fan 6, 6', 6" is inserted in each inlet opening 3. When reference is made below to a fan 6, this means the fans 6, 6', 6" or one of the three fans 6, 6', 6".

[0026] The heat exchanger device can, for example, be arranged on the ceiling of a room by attaching the upper wall 2a to the ceiling. In such an arrangement, the upper wall 2a and the lower wall 2b extend in a horizontal plane parallel to the ceiling of the room.

[0027] As can be seen from the Figures 2 - 4As can be seen, the upper wall 2a contains a sheet 20 with a trapezoidal cross-section, which has a horizontal, outer section 20a, a central section 20b running at an obtuse angle and obliquely inwards, and a horizontal, inner section 20c, and is mirror-symmetrical to the central longitudinal plane of the housing 2. The trapezoidal sheet 20 thus forms a projection 9 running in the region of the central longitudinal plane in the longitudinal direction L, which projection is formed by the inner section 20c and projects inwards relative to the outer section 20a of the housing 2. The horizontal outer section 20a of the sheet 20 delimits the flow cross-section Q of the inflow surface of the heat exchanger (1) at the top. The flow cross-section Q is delimited at the bottom by the lower wall 2b of the housing 2.

[0028] On the projection 9, as for example from Figure 4As can be seen, the fans 6, 6', 6" are arranged. Each fan 6 comprises a rotatable rotor shaft 16 and rotor blades 7 arranged thereon, which extend in the radial direction. The rotor shaft 16 of each fan 6 is rotatably attached to the projection 9 and coupled to a motor (not shown here), which drives the fan 6 in rotation.

[0029] As can be seen from the Figures 2 and 3 As can be seen, the rotor blades 7 of each fan 6 are arranged in a nozzle. The nozzle is formed by a nozzle ring 8 projecting into the interior of the housing 2 and arranged around a circular inlet opening 3. Figures 2 and 3 It is also evident that the rotor blades 7 of the fan 6 partially engage in the nozzle ring 8 and that their remaining, upper part projects beyond the upper edge of the nozzle ring 8.

[0030] The heat exchangers 1 arranged in the housing 2 are evaporators or heat exchangers, for example in the form of finned or ribbed tube heat exchangers or microchannel heat exchangers. Each heat exchanger 1 comprises a plurality of pipes 10 running in the longitudinal direction L and parallel to one another, in which a fluid, for example a coolant or refrigerant, is conducted. The pipes 10 of a heat exchanger 1 can be connected to one another at their front ends via connecting pieces. In this way, multiple passages of the fluid through a heat exchanger 1 can be achieved. By suitable connection of the pipes 10, different strands T1, T2, T3 are formed in a heat exchanger 1, as in Figure 9shown schematically. If a heat exchanger 1 is composed of several heat exchanger blocks 1, 1', 1", the pipes 10 of adjacent heat exchanger blocks 1, 1', 1" are connected to each other to transfer the fluid from one heat exchanger block to the other.

[0031] Below each heat exchanger 1, a collecting channel or tray 11 is arranged, extending in the longitudinal direction L. This serves to collect condensate that may form on the surface of the heat exchangers 1, in particular on the outer surfaces of the pipes 10.

[0032] From the Figures 2 - 4 It is also evident that each heat exchanger 1 is assigned an air guide element 5. In the Figures 2 - 4In the embodiment shown, an air guide element 5a is assigned to the heat exchanger 1a and an air guide element 5b is assigned to the heat exchanger 1b. When reference is made to an air guide element 5 below, this refers to one of the air guide elements 5a, 5b or both. The air guide elements 5 are expediently designed in the form of strips or plates, for example as elongated sheets. Each air guide element 5 assigned to a heat exchanger 1 is arranged upstream and within the cross-section Q of the flow as well as at a distance from the inflow surface of the heat exchanger 1 and extends in the longitudinal direction L of the heat exchanger device. Expediently, each air guide element 5 extends over the entire extent of the heat exchanger device in the longitudinal direction L, as shown, for example, in Figure 4 visible, i.e. over the entire length of the heat exchanger blocks 1, 1', 1" arranged one behind the other in the longitudinal direction L.

[0033] In the Figures 1 - 4In the embodiment shown, each air guiding element 5 has three sections, namely a horizontally running central section and lateral sections angled downwards at an obtuse angle relative to the central section.

[0034] By means of the fans 6, which are preferably designed as axial fans, air is sucked in from the environment and guided through the inlet openings 3 into the interior of the housing 3. The air guide elements 5 assigned to each heat exchanger 1 divide the incoming air flow into two partial flows S1, S2. Each of these partial flows S1, S2 flows in a respective flow direction j1, j2 onto an inflow surface of the assigned heat exchanger 1. The lower partial flow S1 is guided diagonally downwards towards a lower section of the inflow surface of the heat exchanger 1 by the angled shape of the air guide element 5. This redirection of the lower partial flow S1 towards a lower region of the inflow surface of the heat exchanger 1 is achieved in particular by the angled section in the downstream region of the air guide element 5.The upper partial flow S2 is passed between the upper side of the air guide element 5 and the trapezoidal sheet 20 and is partially reflected on the upper wall 2a or the horizontal outer section 20a of the sheet 20. The upper partial flow S2 therefore flows in a flow direction j2, which points slightly diagonally downwards, in an upper section onto the inflow surface of the heat exchanger 1. The air flowing in through an inflow opening 3 is thus divided by the air guide element 5 assigned to the heat exchanger 1 into a lower partial flow S1 and an upper partial flow S2, wherein the lower partial flow S1 is directed by the air guide element 5 and the upper partial flow S2 is directed by the trapezoidal sheet 20 in the direction of the inflow surface of the heat exchanger 1.The two partial flows S1 and S2 impinge on the inflow surface of the heat exchanger 1 in different areas, thereby ensuring a uniform flow onto the heat exchanger 1. The two partial flows S1 and S2 expediently each have the same flow velocity and the same flow density, i.e. the air volume flowing onto the inflow surface of the heat exchanger 1 in the lower partial flow S1 per unit time and area is exactly the same as the air volume flowing onto the inflow surface in the upper partial flow S2.

[0035] To adjust a suitable division of the quantity of incoming air into the partial flows S1 and S2, the air guiding elements 5 can have different shapes, particularly in their upstream area. For example, in the case of the air guiding elements 5, which are located in the Figures 2 - 4are shown, the air quantity in the lower partial flow S1 and in the upper partial flow S2 can be suitably adjusted by a different angular position of the upstream section compared to the middle, horizontal section. The distribution of the air quantity into the two partial flows S1 and S2 can also be varied by the position of the respectively assigned air guide element 5 in relation to the heat exchanger 1 or in relation to the upper wall 2a or the lower wall 2b. It is therefore expedient if the air guide elements 5 are arranged pivotably in the housing 2. Pivotability of the air guide elements 5 can be enabled, for example, by pivotable mounting in the front side walls 2c of the housing 2. By pivoting the air guide elements 5, the flow direction j1 of the lower partial flow can also be adjusted to a desired flow direction on the inflow surface of the assigned heat exchanger 1.It is expedient to set a flow direction j1 which is perpendicular to the inflow surface of the associated heat exchanger 1 or, as shown for example in . Figure 3 visible, is directed slightly downwards. The flow direction j2 of the upper partial flow S2 depends essentially on the shape of the upper wall 2a of the housing 2 and, in the embodiment shown, on the shape of the trapezoidal sheet 20 arranged there. To a lesser extent, the flow direction j2 of the upper partial flow S2 is also influenced by the shape of the air guide element 5.

[0036] Flow simulations have shown that the best flow conditions can be achieved if the axial distance d between the rotor blades 7 of the fan 6 and the projection 9 on which the rotor shaft 16 of the fan 6 is arranged corresponds to at least a quarter of the diameter D of the rotor blades 7 ( Figure 3). Favorable flow conditions also arise when the obtuse angle between the central, horizontal section and the edge sections of the air guide element 5 angled downwards from it is the same size, and in particular lies in the range of 120° to 170°. By changing the angle between the upstream section and the horizontal, central section of the air guide element 5, the air volume in the two partial flows S1, S2 can be adjusted. If the angle between the downstream section and the horizontal, central section of an air guide element 5 is in the range of 160°, the amount of air flowing per unit time and area in the two partial flows S1, S2 onto the heat exchanger 1 is approximately the same. By varying the angle between the horizontal, central section and the angled, downstream section of an air guide element 5, the flow direction j1 of the lower partial flow S1 can be adjusted.

[0037] The width of the horizontal, average distance of an air guide element 5 appropriately corresponds to the width of the downwardly angled sections of the air guide element 5. The total width of the air guide element 5 is in Figure 3 denoted by b. The total width b of the air guiding element 5, i.e. its extension transverse to the longitudinal direction L, is preferably 1 / 3 - 1 / 2 of the diameter D of the rotor blades 7 of the fan 6 ( Figure 3 ).

[0038] Furthermore, flow simulations have shown that optimal flow conditions can be achieved if the air guide element 5 is located approximately centrally with respect to the flow cross-section Q of the heat exchanger 1, i.e. the distance between the upper edge of the nozzle ring 8 and the underside of the central, horizontal section of an air guide element 5 is approximately the same as the distance between the upper side of the horizontal, central section of this air guide element 5 and the horizontally extending, outer section 20a of the sheet 20.

[0039] The flow conditions are further influenced by the position of the air guide elements 5 in relation to the rotor blades 7 of the fan 6. Suitable flow conditions can be achieved if the cross-sectional area of a fan 6 covered by an air guide element 5 is approximately 15% - 25% of the total area of a fan 6 swept by the rotor blades 7 (1 / 4 D 2< π). This is Figure 5 illustrated, wherein the area of a fan 6 covered or covered by an air guiding element 5a or 5b is shown in dashed lines.

[0040] In the Figures 6 - 8 schematically show further embodiments of heat exchanger devices according to the invention, these embodiments as well as the embodiment of the Figures 1 - 5 each comprise two heat exchangers 1a, 1b, which are arranged in a housing with at least one inlet opening 3 and a fan 6 arranged therein. The heat exchangers 1a, 1b are each arranged in an outlet opening 4 in a side wall of the housing 2. Each heat exchanger 1 is assigned at least one air guide element 5, ie the heat exchanger 1a is assigned at least one air guide element 5a and the heat exchanger 1b is assigned at least one air guide element 5b.

[0041] The Figures 6a - 6fshow different embodiments of the air guiding elements 5a, 5b. Figure 6d The embodiment shown corresponds to the embodiment of the Figures 2 - 5 . In the embodiments of the Figures 6d, 6e and 6f is, as in the embodiment of the Figures 1 - 5 , a trapezoidal sheet 20 is arranged on the upper wall 2a of the housing 2. The embodiments of the Figures 6a, 6b and 6c have a flat upper wall 2a and do not contain a trapezoidal sheet 20 on their inner surface. In the embodiments of Figures 6b and 6e The air guiding elements 5 (5a and 5b) each have a horizontal, central section and a downwardly pointing downstream edge section angled therefrom. In the embodiments of the Figures 6c and 6f the air guiding elements 5 are curved with a convex upper side which faces the upper wall 2a of the housing 2.

[0042] In Figure 7Various embodiments are also shown, wherein the embodiments of the Figures 7a, 7b and 7c do not have a trapezoidal sheet 20 on the inside of the upper wall 2a and the embodiments of Figures 7d, 7e and 7f each contain a trapezoidal sheet 20 on the inside of the upper wall 2a. The Figures 7a and 7d The embodiments shown each have air guiding elements 5a, 5b, which are drop-shaped or streamlined. The embodiments of the Figures 7b and 7e each show heat exchanger devices in which each heat exchanger is assigned two air guide elements 5, 5' arranged one above the other, wherein the upper air guide element 5 is offset relative to the lower air guide element 5' towards the respectively assigned heat exchanger 1.

[0043] In the embodiments of the Figures 7c and 7f the air guiding elements 5a, 5b are shaped as in the embodiments of Figure 6aor 6d, but pivoted approximately 45° counterclockwise compared to these embodiments.

[0044] The Figures 8a and 8c The embodiments shown again have drop-shaped or streamlined air guiding elements 5a, 5b, which are pivoted counterclockwise by approximately 45° compared to the embodiments of Figures 5a and 5b.

[0045] In the Figures 8b and 8d Embodiments are again shown in which each heat exchanger 1 is assigned two air guiding elements 5, 5', each of which is roof-shaped.

[0046] Further embodiments for a suitable design, arrangement and shape of air guiding elements 5 can be determined by a person skilled in the art from the examples shown. Figures 6 - 8 develop.

[0047] The number of air guide elements 5 assigned to each heat exchanger 1 is expediently adapted to the size and, in particular, to the height of the respective heat exchanger 1. For taller heat exchangers 1, more than two air guide elements can be assigned to a heat exchanger 1. When using more than one air guide element per heat exchanger, the air flowing in through the inlet opening 3 is divided into more than two partial flows, each of which flows onto the inflow surface of the respective heat exchanger in different areas.

[0048] The use of several air guide elements per heat exchanger is particularly useful for heat exchangers 1 which are subdivided into several strands of pipes arranged one above the other.

[0049] In Figure 9is a schematic illustration of such an embodiment of a heat exchanger device according to the invention with two heat exchangers 1a, 1b, each containing a plurality of pipes 10 grouped into strands T1, T2, T3. The pipes 10 of a heat exchanger 1 are interconnected in such a way that three strands T1, T2, T3 arranged one above the other are formed. These are supplied with a (cool or liquid) fluid in parallel via a supply line 21 and a distributor. The fluid flows through the pipes 10 of the strands T1, T2, T3, exchanging heat with the air flowing through the heat exchanger 1 and is heated or evaporated in the process. The evaporated fluid is collected in a collecting line 22, which is connected to the strands T1, T2, T3 of the heat exchanger 1, and is passed on, for example, to a compressor (not shown here) and downstream condenser.Each heat exchanger 1 is assigned two air guide elements 5, 5'. As a result, the air flowing in through the inlet opening 3 is divided into partial flows S1, S2, and S3, and the partial flows S1, S2, and S3 are directed toward the inflow surface of the heat exchanger 1, as shown in . Figure 9 This is particularly indicated in the heat exchanger 1a. The air guiding elements 5, 5' are shaped and arranged such that a partial flow S1, S2, and S3 is supplied to each branch T1, T2, T3 of the heat exchanger 1, and the respective partial flow flows against the heat exchanger 1 in the region of the inflow surface in which the associated branch T1, T2, or T3 is located.

[0050] In a similar way as in Figure 9As shown, more than three strands can also be provided in each heat exchanger 1. It is not absolutely necessary to divide the air flowing in through an inlet opening 3 into so many partial flows by the air guide elements 5 that each strand of the heat exchanger is assigned a partial flow. It may be sufficient to assign only one air guide element 5 to each heat exchanger 1 in order to ensure a uniform air flow onto the inflow surface of the heat exchanger. Preferably, each strand is evenly supplied with an air flow with the same flow velocity or the same flow density.

[0051] The invention is not limited to the exemplary embodiments illustrated in the drawings. In particular, the number of inlet openings 3 and the fans 6 arranged therein can be adapted to the required performance of the heat exchanger device. Similarly, the number of heat exchanger blocks 1, 1', 1" of a heat exchanger can also be adapted to the required performance of the heat exchanger device.

Claims

1. Heat exchanger device for exchanging heat between air and a fluid guided in at least one heat exchanger (1), the heat exchanger device having a housing (2) with at least one inflow opening (3) and at least one outflow opening (4), in which the or each heat exchanger (1) is arranged and the or each heat exchanger (1) has an inflow surface, through which an air flow flows into the heat exchanger (1), wherein at least one air guide element (5) is associated with each heat exchanger (1), which is arranged within the cross-section (Q) of the inflow surface of the respective heat exchanger (1) and which divides the air flow flowing in through the inflow opening (3) into at least two partial flows (S1, S2) and deflects at least one partial flow (S1) in the direction of the respective heat exchanger (1), wherein each heat exchanger (1) comprises a plurality of pipes (10) grouped in strings (T1, T2, T3), and wherein the air guiding element (5) associated with the respective heat exchanger (1) or the air guiding elements (5, 5') associated with the respective heat exchanger (1) divide the air flow flowing in through the inflow opening (3) into a plurality of partial flows (S1, S2, S3), characterised in that a fan (6) designed as an axial fan is arranged in each inflow opening (3).

2. The heat exchanger device according to claim 1, characterised in that the flow cross-section (Q) of the flow surface of the or each heat exchanger (1) is confined by walls (2a, 2b) of the housing (2).

3. The heat exchanger device according to any one of the preceding claims, characterised in that the housing (2) comprises an upper wall (2a) designed as a cover and a lower wall (2b) designed as a base and side walls (2c) arranged therebetween and perpendicularly thereto, wherein the or each inflow opening (3) is arranged in the lower wall (2b) and the or each outflow opening (4) is arranged in a side wall (2c).

4. The heat exchanger device according to any one of the preceding claims, characterised in that the or each heat exchanger (1) is arranged in an outflow opening (4).

5. The heat exchanger device according to any one of the preceding claims, characterised in that the or each fan (6) has rotor blades (7) and is arranged in the housing (2), the or each inflow opening (3) being surrounded by a nozzle ring (8) projecting into the interior of the housing (2) and the rotor blades (7) of the fan (6) associated with the respective inflow opening (3) engaging at least partially in the nozzle ring (8).

6. The heat exchanger device according to any one of the preceding claims, characterised in that the housing (2) comprises an upper wall (2a) which lies opposite the or each inflow opening (3) and in that this upper wall (2a) has at least one outer section (20a) and one inner section (20c), wherein the outer section (20a) adjoins a heat exchanger (1) and confines the flow cross-section (Q) of the inflow surface of this heat exchanger (1), and the inner section (20b) forms a projection (9) projecting into the interior of the housing (2) in the direction of the inflow opening (3) relative to the outer section (20a').

7. The heat exchanger device according to claim 6, characterised in that at least one fan (6) is fastened to the projection (9) and in that the outer section (20a) and the inner section (20c) as well as the projection (9) projecting into the interior of the housing (2) with respect to the outer section (20a) are formed by a plate (20) which is trapezoidal in cross-section and which is arranged on the upper wall (2a) of the housing (2) or forms the upper wall (2a).

8. The heat exchanger device according to any one of the preceding claims, characterised in that the or each heat exchanger (1) is assigned at least one plate-shaped or strip-shaped air guide element (5), which extends within the flowed-on cross-section (Q) of the flow surface in a longitudinal direction (L) of the heat exchanger device.

9. The heat exchanger device according to any one of the preceding claims, characterised in that the or each air guide element (5) is arranged upstream and in the flow direction (j1, j2) at a distance from the inflow surface of the heat exchanger (1) assigned to it.

10. The heat exchanger device according to one of claims 8 or 9, characterised in that the or each air guide element (5) is angled or curved or streamlined and thereby deflects the air flow of at least one partial flow (S1) in the direction of the associated heat exchanger (1).

11. The heat exchanger device according to any one of the preceding claims, characterised in that two or more air guide elements (5, 5') are assigned to each heat exchanger (1), which are arranged at a distance from one another and above and / or next to one another within the flowed-on cross-section (Q) of the flow surface of the respective heat exchanger (1).

12. The heat exchanger device according to any one of the preceding claims, characterised in that two heat exchangers (1a, 1b) are arranged in the housing (2) and at least one air guide element (5a, 5b) is associated with each heat exchanger (1a, 1b), the arrangement of the heat exchangers (1a, 1b) and the air guide elements (5a, 5b) being mirror-symmetrical with respect to the central longitudinal plane of the housing (2).

13. The heat exchanger device according to any one of claims 5 to 12, characterised in that the or each axial fan is arranged at least partially outside the cross-section (Q) of the heat exchanger (1) or the heat exchangers (1a, 1b) to which the flow is directed.

14. Method for exchanging heat between air and a fluid guided in a heat exchanger (1) by means of a heat exchanger device according to any one of claims 1 to 13, wherein the heat exchanger (1) is arranged in a housing (2) with at least one inflow opening (3) and at least one outflow opening (4) and has an inflow surface, wherein each heat exchanger (1) comprises a plurality of pipes (10) grouped in strings (T1, T2, T3) and at least one air guide element (5, 5') is assigned to each heat exchanger (1), wherein the air guide elements (5, 5') assigned to the heat exchanger (1) divide the air flow flowing in through the inflow opening (3) into a plurality of partial flows (S1, S2, S3), characterised by the following steps: - Intake of ambient air through the inlet opening (3) into the interior of the housing (2), - Splitting the air flow of the ambient air drawn in into at least two partial flows (S1, S2) by flowing the ambient air drawn in past at least one air guide element (5), which is assigned to the heat exchanger (1) and is arranged within the cross-section (Q) of the flow surface of the heat exchanger (1), - Deflection of at least one partial flow (S1) through the or each air guide element (5) in the direction of the flow surface of the heat exchanger (1), - Inflow of the partial flows (S1, S2) into the heat exchanger (1) at different points on the inflow surface, - Outflow of the ambient air conducted through the heat exchanger (1) through the outflow opening (4), after a heat exchange has taken place in the heat exchanger (1) between the ambient air drawn in and the fluid conducted in the heat exchanger (1).

15. The method according to claim 14, characterised in that each of the partial flows (S1, S2) is flowing through the heat exchanger (1) in a flow direction (j1, j2), wherein the flow directions (j1, j2) run at least substantially parallel or obliquely to the horizontal.