WO2020212155A1

WO2020212155A1 - Heat exchanger arrangement with at least one multipass heat exchanger

Info

Publication number: WO2020212155A1
Application number: PCT/EP2020/059400
Authority: WO
Inventors: Alfred Erhard; Hansjörg BRENTROP
Original assignee: Güntner Gmbh & Co. Kg
Priority date: 2019-04-18
Filing date: 2020-04-02
Publication date: 2020-10-22
Also published as: DE202019102229U1; EP3956618A1

Abstract

The invention relates to a heat exchanger arrangement with at least one multipass heat exchanger which comprises: a) a first distributor (1) with a first connector piece (1a) for connection to a fluid line (9), b) a second distributor (2) with a second connector piece (2a) for connection to a fluid line (9'), c) a first diverting distributor (4), d) a second diverting distributor (6) e) and a third diverting distributor (8), f) and a multiplicity of pipelines (5) which can be flowed through by a fluid, in particular water, wherein i) the first distributor (2), the second distributor (2) and the third diverting distributor (8) are arranged at one end (A) of the heat exchanger arrangement and the first and the second diverting distributor (4, 6) are arranged at the opposite end (B), and the pipelines (5) extend from the one end (A) to the opposite end (B), ii) the first connector piece (1a) is arranged at a lowest point (T) or at least in the vicinity of the lowest point (T) of the first distributor (1) and the second connector piece (2a) is arranged at a highest point (T) or at least in the vicinity of the highest point (T) of the second distributor (2), iii) on the second distributor (2), a third connector piece (3) is arranged at a lowest point (H) or at least in the vicinity of the lowest point (H) of the second distributor (2), iv) and, on the third diverting distributor (8), a fourth connector piece (7) is arranged at a lowest point (H) or at least in the vicinity of the lowest point (H) of the third diverting distributor (8).

Description

Heat exchanger arrangement with at least one multi-pass

Heat exchanger

The invention relates to a heat exchanger arrangement with at least one multi-pass heat exchanger, which comprises a first and a second distributor, each with a connection piece for connection to a fluid line, as well as a first, a second and a third deflection distributor and a plurality of pipelines, the pipelines from a fluid, in particular water, can flow through. Such heat exchanger arrangements with at least one multi-pass heat exchanger can be used, for example, as recoolers in cooling systems for cooling a fluid used as a heat transfer medium in the cooling system. The recooler is usually placed outside a facility to be cooled, for example outside a building. If water is used as the heat transfer medium, there is therefore a risk that the heat transfer medium will freeze at the place where the recooler is installed.

From the prior art, therefore, cooling systems with heat exchanger arrangements are known which allow the recooler to be emptied in frost protection mode. For example, from WO2018 / 184908 A1 a cooling system with circulating water as the heat transfer medium is known which contains a recooler and a water tank, the recooler having an input collector and an output collector at a first end area and a second end area opposite the first end area Deflection collector with a first and a second branch, which are arranged in a V-shape to one another, comprises. The first branch and the second branch of the deflection collector are connected to one another via a connecting branch arranged at their upper end, a ventilation opening being arranged in the connecting branch. A first pipe arrangement rising in a flow direction extends between the input collector and the first branch of the deflection collector and a second pipe arrangement falling in the flow direction extends between the second branch of the deflection collector and the output collector. The non-pressurized water tank is connected to an inlet on the inlet header and to an outlet on the outlet header, so that the cooling water stored in the water tank can be passed through the recooler in a closed circuit. For loading and The water tank is in connection with the recooler via a ventilation line that opens into the ventilation opening on the connecting branch of the deflection header. The recooler designed in this way has two series-connected fitting registers with a first pipe arrangement designed as a feed line, which connects the input collector with the deflection collector and forms a first fitting register, and a second pipe arrangement forming a second fitting register, which runs between the deflection collector and the output collector to connect the deflection collector to the output collector. In a recooling mode, the water passed through the pipe arrangements is cooled by exchanging heat with the ambient air that is drawn in. For this purpose, the cooling water stored in the water tank is passed through the recooler by means of a circulation pump. In order to empty the dry cooler when there is a risk of frost, this known cooling system provides for the circulation pump to be switched off. When the circulation pump is switched off, the recooler empties automatically as a result of the constant ventilation of the deflection header in connection with the gradient of the two pipe arrangements of the two fitting registers.

Heat exchanger arrangements with one or more series-connected one-pass registers (one-pass heat exchangers), however, have a lower cooling efficiency compared to multi-pass systems in which the cooling medium passes through the heat exchanger or heat exchangers several times. To improve the cooling efficiency and to increase the cooling performance, heat exchanger arrangements with multi-pass registers are therefore often used. This is particularly necessary when cooling capacities between 100 and 1500 kW are to be achieved. A cooling arrangement with a two-pass register is known, for example, from WO 90/15299-A. The cooling water used as a heat transfer medium flows through a heat exchanger of the cooling system twice (2-pass heat exchanger). For this purpose, a heat exchanger is provided with an input collector arranged at one end of the heat exchanger and an outlet collector as well as a deflection collector arranged at the opposite end, with pipes designed as outgoing lines extending between the input collector and the deflecting collector and pipes designed as return lines between the deflecting collector and the output collector extend. In a recooling mode, the cooling water is first passed through the feed lines in a first pass (first pass) and then in a second pass (second pass) Pass) passed through the return lines. During the passage of the cooling water through the pipes of the two-pass heat exchanger, heat is exchanged with an air flow of the ambient air that is sucked in by a fan and passed through the two-pass heat exchanger to cool the cooling water.

When using multi-pass heat exchangers in areas at risk of frost, there is a risk that the multi-pass heat exchanger cannot be emptied quickly enough or completely to prevent the heat transfer medium (particularly cooling water) from freezing. Particularly in the case of a very rapid temperature drop in the heat transfer medium in the multi-pass heat exchanger as a result of a rapid decrease in the ambient temperature or a strong wind influence on the heat exchanger, it must be ensured, even when using multi-pass heat exchangers, that the heat exchanger can be completely emptied within a very short time to prevent the heat transfer medium from freezing. Rapid emptying of a multi-pass heat exchanger is difficult due to the long pipes through which the heat transfer medium flows several times and the resulting long transport routes for the heat transfer medium through the pipes of the multi-pass heat exchanger. The length of the pipelines (an outward or return line) can be between 3 and 15 m. For the same reason, it is difficult to quickly refill a multi-pass heat exchanger when re-cooling operation is resumed after the risk of frost has ceased.

Proceeding from this, the invention is based on the object of showing a heat exchanger arrangement with at least one multi-pass heat exchanger, which has a high cooling capacity with the highest possible efficiency and is emptied as quickly and completely as possible in the event of a risk of frost and, if possible, for resuming a recooling operation after the risk of frost has ended can be quickly filled with a heat transfer medium.

These objects are achieved according to the invention with a heat exchanger arrangement with the features of claim 1 and with a method with the features of claim 19. A cooling system according to claim 18, in which a heat exchanger arrangement according to the invention is used as a recooler for cooling the fluid (in particular cooling water) used as the heat transfer medium, also contributes to the solution of the object. The heat exchanger arrangement according to the invention comprises at least one multi-pass heat exchanger, in particular a four-pass heat exchanger, wherein the or each heat exchanger has a first and a second distributor, each with a connection piece for connection to a fluid line, as well as a first, a second and a third deflection distributor and comprises a plurality of pipelines through which a fluid used as a heat transfer medium, in particular water, can flow. The first and second distributors and the third deflection distributor are arranged at one end of the heat exchanger arrangement and the first and second deflection distributor are arranged at the opposite end of the heat exchanger arrangement, and the pipes extend from one end to the opposite end, around the first and second distributor to be connected to one of the diversion manifolds. A first connection stub is arranged at a lowest point or at least in the vicinity of the lowest point of the first distributor and a second connection stub is arranged at a highest point or at least in the vicinity of the highest point of the second distributor. On the second distributor, a third connection piece is also arranged at a lowest point or at least in the vicinity of the lowest point of the second distributor and on the third deflection distributor there is also a fourth connection piece at a lowest point or at least in the vicinity of the lowest point of the third deflection distributor arranged.

When speaking of a highest point of a distributor, the geodetically highest point of the respective distributor is meant. When speaking of a lowest point, the geodetically lowest point of the respective facility (distributor) is meant, in particular the lowest point in relation to the vertical direction. A point is also included in each case, which is at least in the vicinity of the geodetically highest or geodetically lowest point.

The inventive design of a heat exchanger arrangement with at least one multi-pass heat exchanger allows both rapid emptying and rapid filling of the multi-pass heat exchanger or heat exchangers with the fluid used as the heat transfer medium by the fluid being drained due to gravity due to the inclination of the pipelines when there is a risk of frost to the horizontal at the same time from all pipelines into the first and second distributor and into the third deflection distributor and from there via one at the lowest point of the first and the second distributor second distributor and the third diverting manifold arranged connection piece can flow into a fluid line connected to the connection piece. In a corresponding manner, in a filling operation, the fluid can be introduced very quickly against gravity from the first and the second distributor and from the third deflection distributor into all the pipelines of the multi-pass heat exchanger. This significantly shortens the emptying or filling time when emptying or filling the heat exchanger, because the fluid is not introduced into the multi-pass heat exchanger or heat exchangers according to the flow paths during recooling operation of the heat exchanger arrangement, but via the first and second distributors and via the third diversion manifold can flow into or out of all pipes of the multi-pass heat exchanger at the same time.

A rapid outflow of the fluid from the pipelines of the multi-pass heat exchanger in the emptying mode is supported by the inclination of the pipelines to the horizontal plane. The pipelines, which expediently run parallel to one another, preferably enclose an angle between 0.5 ° and 5 ° and particularly preferably an angle between 2 ° and 4 °, in particular 3 °, with the horizontal.

The pipes of each multi-pass heat exchanger are divided into a first and a second group of pipes, the first group of pipes serving as feed lines and the second group of pipes serving as return lines. In recooling mode, for example, the fluid can be introduced into the first distributor via the first connection piece, which is designed as an input distributor, and the fluid flows through the feed lines (first group of pipes) to the first deflection distributor and is diverted from there into the return lines (second group of pipes), see above that the fluid then flows back in the return lines to the third diversion manifold at the first end of the heat exchanger arrangement and is diverted there again by the third diversion manifold into pipes of the first group (outgoing lines) and flows to the second diversion manifold and there in turn is diverted into pipes of the second group (return lines) to finally flow back to the second distributor (output distributor). The fluid leaves the multi-pass heat exchanger via the second connection piece arranged at the highest point of the second distributor. The two distributors (first distributor and second distributor) can also be interchanged with one another, ie it is possible for the fluid to first flow into the inlet distributor flows into the second distributor and flows out of the first distributor, which is designed as an output distributor.

In order to ensure that the multi-pass heat exchanger is always completely filled with fluid during filling and during recooling operation (which can achieve improved efficiency), it is preferable that the fluid flows through the first connection piece (at the lowest point of the first distributor ) enters the heat exchanger and leaves the heat exchanger at the second connection piece (at the highest point of the second distributor). A ventilation opening is arranged at least on one of the diversion manifolds, in particular on the first and / or on the second diversion manifold, for pressure equalization with the environment (that is to say with the atmospheric air pressure). The ventilation opening is expediently arranged at a highest point or in the vicinity of the highest point of the respective diversion manifold. In this way, complete ventilation of the diverting manifold can be guaranteed.

The distributors, that is to say the first and second distributors and each deflecting distributor, can each be designed as tubular multiple distributors. The pipes of the distributors can be arranged with their longitudinal axis standing vertically or at an angle to the vertical.

A high heat exchange efficiency and a compact design of the heat exchanger arrangement can be achieved if the heat exchanger arrangement contains two oppositely arranged multi-pass heat exchangers, the two multi-pass heat exchangers being arranged at an angle to the vertical and standing in a V-shape to one another. Corresponding to this inclined arrangement of the heat exchangers, the tubular distributors (first distributor and second distributor as well as the deflection distributors) also run at an angle to the vertical. A particularly compact design can be achieved if the first and the second deflection manifold are contained in a common manifold with a dividing wall arranged therein, the dividing wall dividing the common manifold into an inflow area that forms the first manifold and an outflow area that forms the second Distributor forms, divided. In a corresponding manner, the first and the second deflection distributor, the are arranged adjacent to one another at the other end of the heat exchanger arrangement, in a common manifold with a partition, the partition dividing the manifold into at least two areas, a first area forming the first deflection manifold and a second area forming the second deflection manifold.

In a corresponding manner, the first distributor, the second distributor and the third deflection distributor, which are each arranged adjacent to one another at one end of the heat transfer device, can also be arranged in a common manifold, the manifold in turn containing a separating element which at least in the manifold an inflow area (which forms the first manifold), an outflow area (which forms the second manifold) and a diversion area (which forms the third diversion manifold) are divided. The first, second, third and fourth connecting pieces are arranged in the common collecting pipe, the first connecting piece in the inflow area at a lowest point of the common collecting pipe, the second connecting piece in the outflowing area at a highest point of the common collecting pipe, the third connecting piece is arranged in the outflow area at a lowest point of the common manifold and the fourth connection piece is arranged at a lowest point of the deflection area.

In order to be able to open or close the first and the third connection piece as well as the fourth connection piece, which are each arranged at a lowest point of the relevant distributor (first distributor, second distributor, third deflection distributor), depending on the operating mode of the heat exchanger arrangement, each of these connection pieces is preferred assigned a controllable valve. The controllable valve can in particular be arranged in the respective connection piece (first, second, third or fourth connection piece). The controllable valves can be controlled hydraulically, pneumatically or electrically, for example.

In an expedient embodiment of the heat exchanger assembly, the first and second distributors and the third deflection distributor are arranged at a front end of the heat exchanger assembly and the first and second deflection distributors are arranged at the opposite, rear end of the heat exchanger assembly. As a result, a compact construction and a dimensioning of the heat exchanger arrangement corresponding to the requirements with regard to the cooling capacity can be ensured. The heat exchanger arrangement according to the invention can be used in various operating modes, in particular in a recooling mode, a draining mode when there is a risk of frost, a filling mode for the first filling of the heat exchanger system or for a refilling after the risk of frost has ended and in a stand-by mode after the heat exchanger system has been emptied when there is a risk of frost be operated in persistent frost. To switch the heat exchanger arrangement from one operating mode to another operating mode, a control device for controlling the heat exchanger arrangement is provided. The control of the heat transfer arrangement and in particular the setting of a suitable operating mode takes place as a function of Ehngebungsparametem, such as the outside temperature and the wind speed at the installation site of the heat transfer arrangement. In order to detect the setting parameters, it is expedient to provide sensors, in particular a thermometer to detect the outside temperature and an anemometer to detect the wind speed, and are coupled to the control device. The measured values of the environmental parameters recorded by the sensors are fed to the control device. Besides the

Ambient parameters such as outside temperature and wind speed is expediently detected by further sensors, in particular thermometers, the inlet temperature of the fluid when it enters the heat exchanger arrangement. Furthermore, the volume flow of the fluid flow flowing into the heat exchanger arrangement or the fluid flow flowing out of the heat exchanger arrangement can be measured via pressure or flow sensors and fed to the control device. On the basis of the supplied measured values, in particular taking into account the outside temperature and the inlet temperature of the fluid, the control device calculates a predicted outlet temperature of the fluid when it emerges from the heat exchanger arrangement. If the calculated outlet temperature is greater than or equal to a predetermined limit value, the control device switches the operation of the heat exchanger arrangement from recooling operation to draining operation. From the computationally determined outlet temperature of the fluid when it emerges from the heat exchanger arrangement, a risk of freezing of the fluid can be detected at low outside temperatures below the freezing point of the fluid (which is preferably water). In order to prevent the fluid from freezing in the pipelines or the distributors of the heat exchanger arrangement in such a situation, the control device switches as quickly as possible to the emptying mode, in which the fluid in the pipelines simultaneously from all pipelines in the first and in the second distributor as well as the third diversion distributor and from there through the connecting pieces (first, third and fourth connecting pieces) arranged at the lowest point of these distributors into a fluid line connected to these connecting pieces from the frost-prone area.

These and other features and advantages of the invention emerge from the exemplary embodiment described in more detail below with reference to the accompanying drawings. The drawings show:

Fig.l: Representation of an embodiment of an inventive

Heat exchanger arrangement with two multi-pass heat exchangers arranged in a V-shape to one another in a view of a front end face of the heat exchanger arrangement;

FIG. 2: side view of the heat exchanger arrangement from FIG. 1;

Fig. 3: Schematic representation of different operating modes of the

Heat exchanger arrangement of Figures 1 and 2, wherein in Figure 3a a recooling operation, in Figure 3b a filling operation and in Figure 3c an emptying operation of a multi-pass heat exchanger of the heat exchanger arrangement is shown;

Fig. 4: Schematic representation of a cooling system which contains a heat transfer device according to the invention, wherein the

Heat exchanger arrangement is shown in the view of Figure 1 and the side view of Figure 2;

FIG. 5: Detailed representation of the cooling system from FIG. 4 in the area of

Heat exchanger arrangement;

Fig. 6: Schematic representation of different operating modes of the

Heat exchanger arrangement of the cooling system from FIG. 4, FIG. 6a showing the heat exchanger arrangement in recooling operation, FIG. 6b the The heat exchanger arrangement in the emptying mode and FIG. 6c shows the heat exchanger arrangement in the filling mode;

7: Schematic representation of a further exemplary embodiment with a

Combination of two heat exchanger arrangements according to

Invention;

Fig. 8: Schematic representation of possible operating modes of the combination of

Heat exchanger arrangements from FIG. 7.

In Figures 1 and 2, an embodiment of a heat exchanger arrangement according to the invention is shown, which can be used as a recooler R for cooling a fluid used as a heat transfer medium in a cooling system. In particular, water can be used as the heat transfer medium. When water is spoken of in the following, the fluid used as the heat transfer medium is meant, it being possible for another fluid to be used as the heat transfer medium instead of water.

The heat exchanger arrangement shown in FIGS. 1 and 2 contains two four-pass heat exchangers which contain planar heat exchangers that are opposite one another and run at an angle to the vertical. As can be seen from the view of FIG. 1, the two heat exchangers are arranged in a V-shape to one another. The structure of the heat exchanger arranged on the right-hand side of FIG. 1 is explained below. The opposite heat exchanger arranged on the left side of the heat exchanger arrangement is constructed accordingly. The two heat exchangers are attached to a housing 21 of the heat exchanger arrangement. Each heat exchanger comprises a first distributor 1, which is designed as an input distributor, a second distributor 2, which is designed as an output distributor, as well as a first diversion distributor 4, a second diversion distributor 6 and a third diversion distributor 8, and a plurality of pipes 5. The first Manifold 1, the second manifold 2 and the third deflection manifold 8 are arranged at the front end A of the heat exchanger arrangement. The first and second deflection manifolds 4, 6 are each arranged at the opposite end B of the heat transfer device, that is to say on the rear end face. The pipes 5 extend in a longitudinal direction L of the heat exchanger arrangement from one end A to the opposite end B. The pipes 5 are divided into a first group of pipes 5a and a second group of pipes 5b, the first group of pipes 5a serving as outgoing lines and the second group of pipes 5b serving as return lines. Some of the pipelines 5 of the first group of pipelines 5a (feed lines) connect the first manifold 1 (inlet manifold) to the first elbow distributor 4 and some of the pipelines 5 of the second group of pipelines 5b (return lines) connect the first elbow distributor 4 to the third Elmenkverteiler 8. A part of the pipes of the first group of pipes 5a (outgoing lines) in turn connects the third Elmlenkverteiler 8 with the second Elmlenkverteiler 6 and part of the pipes of the second group of pipes 5b (return lines) in turn connects the second Elmlenkverteiler 6 with the second Distributor 2 (output distributor), as can be seen from FIG. The pipelines 5 of the outgoing and return lines run at least essentially parallel to one another and are slightly inclined to the horizontal, as can be seen from FIG. The angle of inclination of the pipelines 5 to the horizontal is preferably between 0.5 ° and 5 °, particularly preferably between 2 ° and 4 °, and in a preferred embodiment, the angle between the pipelines and the horizontal plane is 3 °.

On the first distributor 1 (input distributor), a first connection piece 1 a is arranged at a lowest point T of this distributor 1. At a corresponding point, i.e. at a lowest point T, a connecting piece 3 is also arranged on the second distributor 2 (outlet distributor). This connecting piece 3 is referred to as the third connecting piece 3. On the second distributor 2 (output distributor), a further connection stub is arranged at a highest point H, which is referred to as second connection stub 2a. At the lowest point T of the third Elmlenkverteilers 8 a connection piece 7 is also arranged, which is referred to as the fourth connection piece.

The elbow distributors (first and second elbow distributors 4, 6) arranged at the opposite end B of the heat exchanger arrangement each have a ventilation opening 10 at a highest point H, as can be seen from FIG. The ventilation opening 10 is expediently arranged at the upper end of the elbow joint distributor 4, 6, which is designed as a tubular multiple distributor. The opposite lower end of the tubular Elmlenkverteiler 4, 6 is closed. In each ventilation opening 10, a valve 11 is expediently arranged, with which the ventilation opening 10 can be opened or closed. On the use of a valve in the ventilation openings 10 can, however, also be dispensed with.

At least in the third connection piece 3, which is arranged at the lower end of the second distributor 2 (output distributor), and in the fourth connection piece 7, which is arranged at the lower end of the third diverting distributor 8, there is a controllable valve V for opening and closing of the respective connection piece 3, 7 inserted (Figure 2). The respective valve V can alternatively also be placed at a different point, for example in a fluid line connected to the respective connection piece 3, 7. The valves V can be controlled independently of one another in order to open or close the connecting pieces 3, 7 independently of one another

Various operating modes of the heat exchanger arrangement are shown schematically in FIG. In the recooling mode shown in FIG. 3a, water is passed as a heat transfer medium through the pipes 5 (supply lines 5a and return lines 5b) of the heat exchanger arrangement. At the same time, (cold) ambient air is sucked in from the environment by at least one fan 12, which is provided on the top of the heat exchanger arrangement, as can be seen from FIGS. 1 and 2, and passed through the heat exchangers of the heat exchanger arrangement in order to ensure heat exchange between the Pipelines 5 conducted heat transfer medium (water) and the sucked in air. To increase the heat transfer efficiency, fins 22 are attached to the pipes 5 (FIG. 3) in order to increase the effective heat transfer surface. In the exemplary embodiment shown, the heat exchangers are accordingly lamellar or finned tube heat exchangers. Instead of conventional lamellar or finned tube heat exchangers, microchannel heat exchangers can also be used in the heat exchanger arrangement according to the invention.

In the recooling mode shown schematically in Figure 3a, the fluid used as the heat transfer medium is introduced into the first distributor 1 (inlet distributor) via the first connection piece 1 a and from there through part of the pipes 5 of the first group of pipes 5 a (outgoing lines) to the first deflection distributor 4 directed and diverted into part of the pipelines of the second group of pipelines 5a (return lines). The fluid flows through the return lines to the third diversion distributor 8 and is there again in part of the pipelines 5 of the first group deflected by pipelines 5a (feed lines). The fluid flows in the feed lines to the second diverting distributor 6 and is in turn diverted into part of the tubing of the second group of tubing 5a (return lines) and finally flows into the second distributor 2 (output distributor). The fluid is withdrawn from the outlet manifold 2 through the second connection stub 2a located at the upper end of the outlet manifold 2 and fed as a cooling medium into a cooling medium reservoir (container B) or directly to a consumer to be cooled via a fluid line 9 connected to the second connection stub 2a.

In the recooling operation according to FIG. 3a, the connecting pieces 3 and 7 (third and fourth connecting pieces) are each closed by the valve V arranged therein.

In FIG. 3b, the heat exchanger arrangement is shown schematically in a filling mode in which the heat exchanger can either be filled for the first time or refilled with the fluid after it has been emptied. In the filling mode, the connecting pieces 3 and 7 (third and fourth connecting pieces), which are each arranged at the lower end of the second distributor 2 and the third deflection distributor 8, are open. As a result, the fluid can be filled into the first and second distributors 1, 2 and the third deflector 8 at the same time via the connecting pieces 1 a, 3 and 7 arranged at the lower end of the two distributors 1, 2 and the third deflecting distributor 8. The fluid then flows, as shown in Figure 3b, simultaneously through all pipelines 5 (i.e. both through the feed lines 5a and through the return lines 5b) from one end A of the heat exchanger arrangement to the opposite end B. Due to the inclination of the pipelines 5 towards the front end A, the fluid in the pipelines 5 flows upwards against gravity in the direction of the diversion manifolds 4, 6 arranged at the rear end B. The air in the first and second diversion manifolds 4, 6 is through the ventilation openings 10 at the upper end of these two diversion manifolds 4, 6 are pressed out, whereby the two diversion manifolds 4, 6 are vented. In order to prevent the fluid from escaping from the ventilation openings 10 when the heat exchanger is completely filled with the filled fluid, an automatically closing valve 11 is expediently arranged in the ventilation openings 10. The valve 11 closes the ventilation opening 10 automatically as soon as an internal pressure arises in the valve due to the fluid entering. Corresponding to the filling of the heat exchanger arrangement with the fluid, conversely, by opening the valves V in or on the third connection stub 3 and on the fourth connection stub 7, the heat exchanger arrangement can also be quickly emptied. In Figure 3c, a draining operation of the heat exchanger arrangement is shown, in which, when the valves V in the third connection piece 3 and in the fourth connection piece 7 are open, the fluid from all pipelines 5 (that is, both from the inlet lines 5a and from the return lines 5b) along the gradient due to gravity of the pipelines 5 can flow from the rear end B to the front end A into the first and second manifolds 1, 2 and into the third diversion manifold 8. The flow of the fluid is promoted on the one hand by the inclination of the pipelines 5 towards the front end A and on the other hand by aeration of the first and second deflection manifolds 4, 6 via the ventilation openings 10. To ventilate the first and second diversion manifolds 4, 6, the valve 11 in the ventilation openings 10 is opened so that ambient air can flow into the diversion manifolds 4, 6 through the ventilation openings 10. The fluid can finally flow off through the connecting pieces 1 a, 3 and 7 (first, third and fourth connecting pieces) into a fluid line, not shown here, which is connected to the connecting pieces 1 a, 3 and 7.

The inventive design of the heat exchanger allows both rapid filling with the fluid and (if there is a risk of frost) rapid emptying of the heat exchanger arrangement, because the fluid both during filling and emptying simultaneously and in the same direction of flow through all pipeline 5 of the Heat exchanger assembly can flow in or out. FIG. 4 shows an example of a cooling system in which a heat exchanger arrangement according to the invention can be used. The cooling system shown schematically in FIG. 4 comprises a circuit K in which a fluid, in particular water, is conducted as the heat transfer medium, a container B connected to the circuit K and in which the fluid is stored, a heat source Q, which supplies the fluid at the location of the heat source supplies heat, as well as at least one heat exchanger arrangement according to the invention, which is used in the cooling system as a heat exchanger R to cool the fluid by exchanging heat with the ambient air. The recooler R of the cooling system shown in FIG. 4 is connected to the container B via fluid lines 9. The container B is preferably open to the surroundings of the container location. A fluid line 19 leads from the container B to the heat source Q in order to guide the cooled fluid stored in the container B as a cooling medium to the heat source Q. A first pump PI is provided to convey the fluid from the container B to the heat source Q. At the location of the heat source Q, the fluid is heated by heat exchange and passed back to the recooler R through a further line 29. A second pump P2, which conveys the fluid from the heat source Q back to the recooler R, is expediently arranged in the line 29. A branch line 30 branches off from the line 29 into the container B. A valve V4 is provided for opening and closing the branch line 30. Another valve V3 is arranged downstream of the branch line 30 in the line 29. The line 29 branches off at a branch Z into a return line 31 to the container B and into a feed line 32 leading to the recooler R. In the return line 31, a further valve V2 is arranged for opening and closing this line. The supply line 32 branches into a central supply line and two secondary lines, in each of which a three-way valve VI is arranged. The central supply line branches off again into two branches, a first branch being connected to the first connecting piece la of the left heat exchanger and a second branch being connected to the first connecting piece la of the right heat exchanger. The secondary lines lead to the third connection piece 3 of the left and right heat exchangers, as can be seen from FIG. The supply line 32 is thus connected to the connecting pieces la, 3 and 7 of the heat exchanger arrangement via the three-way valves VI. A discharge line 33 is connected to the (upper) second connection piece 2a of the heat exchanger arrangement, which leads to the line 9 and is connected to it.

Various operating modes of the heat transfer device in the cooling system of FIG. 4 can be seen from FIG. The fluid in the warm state is indicated by a broken line and in the cold state with a solid line. If there is a dotted line, there is no fluid flow.

In Figure 6a, the cooling system of Figure 4 is shown in the recooling mode. The valves V2 and V4 are closed, so that the lines 30 and 31 are closed. The valve V3 is open so that the fluid heated by the heat source Q can flow through the lines 29 and 32 to the recooler R. The three-way valves VI are closed, so that Fluid can flow from the line 32 to the first connection piece 1 a of the first distributor 1 (input distributor) of the two multi-pass heat exchangers and can thus enter the heat exchanger arrangement. After the fluid has passed through the multi-pass heat exchanger of the recooler R several times, the cooled fluid leaves the recooler R at the second connection port 2a and flows through the line 33 connected to the second connection port 2a to the line 9 and from there into the container B, in which the cooled fluid is stored.

In the emptying mode shown in FIG. 6b, valves V2 and V4 are open and valve V3 is closed. The three-way valves VI are switched in such a way that the fluid can flow from the lower connection pieces la, 3 and 7 (first connection piece, third and fourth connection piece) into the fluid line 9 connected to this connection piece and from there directly into the container B. During the emptying of the recooler R, the fluid heated by the heat source Q is returned to the container B via the branch line 30 with the valve V4 open, without the fluid being passed through the recooler R.

In the filling operation shown in Figure 6c, the valves V2 and V4 are closed and the valve V3 is open. The three-way valves VI are controlled in such a way that the fluid heated by the heat source Q is conducted via the lines 29 and 32 to the lower connecting pieces la, 3 and 7 (first, third and fourth connecting pieces) of the multi-pass heat exchanger and from there into the Recooler R enters. After the heat exchanger of the recooler R has been completely filled, the recooler is switched to recooling mode (FIG. 6a).

FIG. 7 shows an exemplary embodiment of a cooling system in which two heat exchanger arrangements according to the invention can be used as dry coolers RI, R2 in parallel or series operation. The two dry coolers RI, R2 can be used, for example, connected in series at the same time for cooling the fluid used as the heat transfer medium in the cooling system. If both dry coolers RI, R2 are used at the same time, the cooling system achieves maximum cooling performance. If a lower cooling capacity is required for adequate cooling of the fluid, one of the two dry coolers RI or R2 can be switched off by the control device of the cooling system. In series operation, in which both dry coolers RI, R2 are operated simultaneously to cool the fluid, valves V2 and V4 are closed and valve V3 is open, so that the fluid heated by heat source Q flows through to the two dry coolers RI, R2 the first connection piece la can be initiated. The fluid cooled in the dry coolers RI, R2 leaves the dry coolers RI, R2 at the second connection stub 2a and flows through the fluid line 9 connected to the second connection stub 2a into the container B (as shown in FIG. 7). In the operating mode of the cooling system of FIG. 7 shown in FIG. 8a, the valves V3 and V4 are closed and valve V2 is open. As a result, only the second recooler R2 is operated in recooling mode. The first dry cooler RI is in standby mode in which no fluid is passed through the pipes of the first dry cooler RI.

In the operating mode shown in Figure 8b, the second recooler R2 is operated with the valve V3 open and valves V2 and V4 closed in recooling mode, in which the fluid heated by the heat source Q is introduced into the heat exchanger of the second recooler R2 via the first connection piece la and there cooled and finally guided out through the second connection piece 2a from the second recooler R2 via the fluid line 9 connected to the second connection piece 2a and conducted into the container B. At the same time, the first dry cooler RI is operated in the filling mode, in which the fluid is introduced into all pipes 5 of the first dry cooler RI via the first connection piece la, the third connection piece and the fourth connection piece 7 of the heat exchanger in order to completely fill the dry cooler RI with fluid to fill.

To control the heat exchanger arrangement according to the invention in the various operating modes, a plurality of sensors S1, S2 is expediently used, with which environmental parameters such as the outside temperature (Tu) and / or the wind speed (v) can be recorded and sent to a control device S for processing. In addition to the environmental parameters, the inlet temperature (T _e in) of the fluid when entering the heat transfer arrangement, the temperature of the fluid in the deflecting distributors 4, 6 and the pressure or the flow rate of the fluid when entering are expediently via further sensors TI, T2, P the input distributor 1 recorded.

The control device denoted by reference symbol S in the diagram of the cooling system in FIG. 4 is coupled to the valves V, VI, V2, V3 and V4 in order to control them. The from the sensors S1, S2; TI, T2, P recorded measured values are sent to the control device and the control device calculates an exit temperature (T _out ) of the fluid when it exits the heat exchanger arrangement on the basis of the recorded measured values. When calculating the value of the outlet temperature (T _out ), the parameters of the heat exchanger arrangement, in particular its thermal output, the dimensioning of the heat exchanger, the number of passes of the fluid through the pipelines, the fluid used as the heat transfer medium and the volume flow of the fluid through the Pipelines, taken into account in order to determine a (maximum) cooling of the fluid when emptying the heat exchanger arrangement. The control device controls the valves of the heat exchanger arrangement in such a way that the heat exchanger arrangement is operated in recooling mode as long as the calculated outlet temperature (T _out ) is greater than or equal to a predetermined limit value (T _min ). As soon as the calculated outlet temperature (T _out ) falls below the limit value (i.e. when T _out <T _min ), the heat exchanger arrangement is switched to draining mode. Switching takes place, for example, by electrical or pneumatic control of valves V, VI, V2, V3 and V4.

The specified limit value (T _min ) is expediently a value D above the freezing point of the fluid used as the heat transfer medium (i.e. above 0 ° C. for water), the value D representing a safety margin from the freezing point.

This ensures that the fluid does not freeze if there is a risk of frost, even if it is emptied quickly. The value D (and thus the limit value T _min = 0 ° C. + D when using water as the heat transfer medium) is preferably between 1 ° C. and 7 ° C. After it has been completely emptied, the heat exchanger is left in stand-by mode in which the heat exchangers are not filled with fluid. In the stand-by mode, it is monitored whether the risk of frost has been eliminated or whether it continues to exist by calculating the predicted outlet temperature (T _out ) based on the recorded environmental parameters and comparing it with the limit value. As soon as the calculated outlet temperature (T _out ) is greater than or equal to the specified limit value (T _min ), the control device switches the heat exchanger arrangement from standby to filling mode. After the heat exchanger arrangement has been completely filled, it is switched to recooling mode and operated until the calculated outlet temperature (T _out ) is below the limit value. In the exemplary embodiment in FIG. 7, the heat exchanger arrangement comprising a plurality of heat exchangers is activated by the control device in such a way that the individual multi-pass heat exchangers can be operated independently of one another in the various operating modes. The control device controls the number of heat exchangers operated in the recooling mode as a function of the recorded ambient parameters and / or the recorded inlet temperature (Tein) of the fluid in order to be able to provide the required cooling capacity. The fluid volume passed through the heat exchanger arrangement per unit of time expediently remains the same regardless of the number of heat exchangers operated in recooling mode. The control device monitors whether the temperature of the fluid that is cooled in the heat exchanger and stored in the container is in a preferred temperature range between a minimum and a maximum temperature. The preferred temperature range can be between 15 ° C and 22 ° C, for example.

Claims

Expectations

1. Heat exchanger arrangement with at least one multi-pass heat exchanger, which comprises:

a) a first distributor (1) with a first connection piece (la) for connection to a fluid line (9),

b) a second distributor (2) with a second connection piece (2a) for connection to a fluid line (9 ‘),

c) a first diversion manifold (4),

d) a second diversion manifold (6)

e) and a third diversion distributor (8),

f) and a plurality of pipelines (5) through which a fluid, in particular water, can flow,

in which

i) the first distributor (2), the second distributor (2) and the third diverting distributor

(8) are arranged at one end (A) of the heat exchanger arrangement and the first and second deflection manifolds (4, 6) are arranged at the opposite end (B) and the pipes (5) extend from one end (A) to the opposite end (B ) extend,

ii) the first connection piece (la) at a lowest point (T) or at least in the vicinity of the lowest point (T) of the first distributor (1) and the second connection piece (2a) at a highest point (T) or at least in the Near the highest point (T) of the second distributor (2) is arranged, iii) on the second distributor (2) a third connection piece (3) at a lowest point (H) or at least in the vicinity of the lowest point (H) of the second

Distributor (2) is arranged,

iv) and on the third diversion manifold (8) a fourth connecting piece (7) is arranged at a lowest point (H) or at least in the vicinity of the lowest point (H) of the third diversion distributor (8).

2. Heat exchanger arrangement according to claim 1, wherein the pipes (5) of a first group of pipes (5a) are connected to the first manifold (1) and the first deflection manifold (4) and that the pipes of a second group of pipes (5b) are connected to the second manifold (2) and the second

Deflection manifolds (6) are connected.

3. Heat exchanger arrangement according to one of the preceding claims, wherein at least the first and / or the second deflection manifold (4, 6) is equipped with a ventilation opening (10) for pressure equalization with the environment.

4. Heat exchanger arrangement according to claim 3, characterized in that the ventilation opening (10) is arranged in each case at a highest point (H) or in the vicinity of the highest point (H) of the respective deflection manifold (4, 6).

5. Heat exchanger arrangement according to one of the preceding claims, wherein the first distributor (2), the second distributor (2) and each deflection distributor (4, 6, 8) is each designed as a tubular multiple distributor, which is preferably arranged so that its longitudinal axis is vertical stands or is inclined to the vertical.

6. Heat exchanger arrangement according to one of the preceding claims, characterized in that the first and the second deflection manifold (4, 6) are arranged in a common manifold with at least one partition which divides the manifold into two or more areas.

7. Heat exchanger arrangement according to one of the preceding claims, characterized in that the first distributor (1) and the second distributor (2) are arranged in a common collecting pipe, wherein the collecting pipe comprises a separating element which divides the collecting pipe into an inflow area and a

Divided outflow area.

8. Heat exchanger arrangement according to one of the preceding claims, characterized in that the first manifold (1) and the second manifold (2) and the third deflection manifold (8) are arranged in a common manifold, wherein the manifold comprises a separating element which the manifold divided into an inflow area, an outflow area and a deflection area, at least one connection piece being provided in the deflection area for connection to a fluid line (9).

9. Heat exchanger arrangement according to one of the preceding claims, characterized in that a controllable valve is arranged or assigned in the first connection piece (la) and / or in the third connection piece (3).

10. Heat exchanger arrangement according to one of claims 2 to 9, characterized in that a controllable valve is arranged in the fourth connection piece (7) or is assigned to the fourth connection piece (7).

11. Heat exchanger arrangement according to one of the preceding claims, wherein the pipes (5) run parallel to one another and at an angle to the horizontal, the angle that the pipes (5) enclose with the horizontal, preferably between 0.5 ° and 5 ° and particularly preferred is between 2 ° and 4 °.

12. Heat exchanger arrangement according to claim 11, characterized in that in an emptying operation, the fluid flows due to gravity from all pipes (5) into the first distributor (1) and the second distributor (2) and that in a filling operation, the fluid against gravity from the first manifold (1) and the second manifold (2) flows into the pipes (5).

13. Heat exchanger arrangement according to one of the preceding claims, characterized in that the third deflection manifold (8) and the first manifold (1) and the second manifold (2) at a front end (A) of the Heat exchanger arrangement are arranged and that the first deflection distributor (4) and the second deflection distributor (6) are arranged on the opposite end face of the heat exchanger arrangement.

14. Heat exchanger arrangement according to one of the preceding claims, characterized in that in an emptying operation, the fluid flows due to gravity from all pipes (5) into the first distributor (1) and the second distributor (2) and at least into the third deflection distributor (8) and that in a filling operation, the fluid flows against gravity from the first distributor (1) and the second distributor (2) as well as from the third diversion distributor (8) into all pipelines (5).

15. Heat exchanger arrangement according to claim 14, characterized in that the fluid in the emptying operation due to gravity via the first connecting piece (la) and the third connecting piece (3) and via the fourth connecting piece (7) of the third diverting manifold (8) into a lower fluid line (9 ), which is connected to the first, third and fourth connecting pieces (la, 3, 7).

16. Heat exchanger arrangement according to one of the preceding claims, characterized by a plurality of sensors (S1, S2) for detecting environmental parameters, in particular the outside temperature and / or the wind speed.

17. Heat exchanger arrangement according to one of the preceding claims, characterized by a control device (S) for controlling the heat exchanger arrangement, the heat exchanger arrangement via the control device as a function of ambient parameters, in particular the outside temperature and / or the wind speed, in a recooling mode, a draining mode or a filling mode is operable.

18. Comprehensive cooling system

- a circuit (K) in which a fluid, in particular water, is conducted as a heat transfer medium,

- a container (B) which is connected to the circuit (K) and in which the fluid is stored,

- a heat source (Q), which supplies heat to the fluid at the location of the heat source,

- and a dry cooler (R) in which the fluid is cooled by heat exchange with the ambient air,

characterized in that the recooler (R) at least one

Contains heat exchanger arrangement according to one of the preceding claims.

19. The method for operating a cooling system according to claim 18, wherein the heat exchanger arrangement is operated as a function of ambient parameters, in particular the outside temperature, in a recooling operation, a draining operation or a filling operation, characterized in that the fluid in the recooling operation is via the first connection piece (la ) at the lowest point (T) or at least in the vicinity of the lowest point (T) of the first distributor (1) introduced into the heat exchanger arrangement and via the third connection piece (3) at the highest point (H) or at least in the vicinity of the highest point (H) of the second distributor (2) is derived that in the emptying operation the fluid due to gravity from all pipelines (5) into the first distributor (1) and the second distributor (2) as well as into the third deflection distributor (8) and from there via one at the lowest point (T) or at least in the vicinity of the lowest point (T) of the first distributor (2), of the second distributor (2) and the third diversion distributor (8) arranged connection piece (la, 3, 7) flows into a fluid line (9), and that in the filling operation the fluid against gravity from the first distributor (1) and the second Manifold (2) as well as from the third diversion manifold (8) flows into all pipelines (5).

20. The method according to claim 19, characterized in that the environmental parameters, in particular the outside temperature (Tu) and / or the wind speed (v), as well as the inlet temperature (T _em ) of the fluid when entering the heat transfer arrangement by means of sensors (S1, S2 ; TI) are recorded and sent as measured values to a control device (S) and that the

Control device calculates an outlet temperature (T _out ) of the fluid on the basis of the recorded measured values when it exits the heat exchanger assembly and operates the heat exchanger assembly in recooling mode as long as the calculated outlet temperature (T _out ) is greater than or equal to a predetermined limit value (Tmin) and the heat exchanger assembly is in switches over the emptying mode when the calculated outlet temperature (T _out ) is below the limit value (T _min ).