CH713882B1 - Plate-shaped heat exchanger for the recovery of latent heat from water. - Google Patents

Abstract

The invention relates to a plate-shaped heat exchanger (1) for the recovery of latent heat from water. The heat exchanger (1) has a feed (2) and a discharge (3) for a heat exchange medium, by means of which, in the intended operation, in which the heat exchanger (1) is immersed in a substantially vertical orientation completely in water, the heat exchanger ( 1) ambient heat is removed, with the formation of ice on the two plate surfaces (4a) of the heat exchanger (1). The heat exchanger (1) has one or more barrier elements (5, 6), which are designed such that they grow into the areas formed in the intended operation on the plate surfaces (4a) into areas which are in normal operation in Direction of gravity (S) as seen under the inlet and outlet (2, 3) are prevented.

Description

Description: The present invention relates to a plate-shaped heat exchanger for the recovery of latent heat from water, to an arrangement for the recovery of latent heat from water with such a heat exchanger and to the use of the heat exchanger or the arrangement for obtaining latent heat from water by means of a heat pump.

In the utilization of environmental heat by means of heat pumps, it is known to use low-temperature water as an energy source. The heat is extracted from the water with heat exchangers. If the temperature level of the water is very low or if the available amount of water is very limited, then the amount of energy that is used in the transition of the water to ice (latent heat) is also used. However, this results in the problem that forms ice on the heat exchanger surfaces, which increasingly hampers the heat exchange with increasing layer thickness. To ensure efficient operation, this ice must be removed when a certain layer thickness is reached. Similar problems arise in the industrial production of ice with heat exchangers.

From DE 19 839 867 C2, which has a method for ice production to the subject, various methods for detaching the produced ice from the heat exchanger are known. For example, it is proposed to remove the ice by means of a heated or pressurized separating fluid, or mechanically by comminution and / or by blasting as a result of mechanical deformation of the heat exchanger.

From US 2 683 356, which has a method for the production of layered ice sheets to the subject, it is known to demolish the ice sheets by deformation of the heat exchanger surfaces.

The aforementioned methods all have the disadvantage that they require a considerable investment outlay, which brings corresponding investment and maintenance costs and the reliability is detrimental. Accordingly, these methods are only partially suitable for practical applications.

From DE 2 450 537 A1, which has a method for storing cold to the object, a method is known in which the detachment of the ice sheets from the heat exchangers by a temporary heating of the heat exchanger surfaces as a result of supplying a heated medium to the heat exchanger is effected. This method avoids the aforementioned disadvantages of the prior art, but in turn has the disadvantage that relatively much heat energy is required to completely detach the ice sheets from the heat exchangers.

It is therefore the task of providing a technical solution that does not have the aforementioned disadvantages of the prior art or at least partially avoids.

This object is solved by the subject matters of the independent claims.

Accordingly, a first aspect of the invention relates to a plate-shaped heat exchanger for the recovery of latent heat from water. The heat exchanger has a feed and exhaust for a heat exchange medium, e.g. Glycol or a refrigerant of a heat pump, on, by means of which in the normal operation of the water, which surrounds the heat exchanger, is withdrawn to form ice on the two plate surfaces of the heat exchanger heat. In normal operation, the heat exchanger with vertically oriented plate surfaces is completely submerged in water.

The heat exchanger has one or more barrier elements, which are designed such that it is a ingrown growing in the normal operation on the plate surfaces forming ice sheets in areas which in normal operation in the direction of gravity seen under the supply and discharge for the heat exchanger medium, prevent.

Due to the inventive design of the heat exchanger can be prevented that in a detachment of the ice plates from the heat exchanger by a temporary heating of the heat exchanger surfaces of the actual heat exchanger surfaces dissolved ice sheets stuck to the supply and discharge and only then can swim up when the ice in contact with it has melted away. As a result, much less heat energy is needed to remove the ice sheets.

Advantageously, the barrier elements are designed such that they prevent ingin growing on the plate surfaces forming ice sheets in the areas of the supply and discharge inside. As a result, a clear separation between the forming at the inlet and outlet ice and the forming on the plate surfaces ice plates can be achieved.

Preferably, the barrier elements are designed such that they form in normal operation in a direction opposite to the direction of gravity, ie in the Aufschwimmrichtung the dissolved ice sheets, no positive connection with the forming on the plate surfaces ice sheets. In this way, the heat energy requirement can be further reduced, because the ice sheets, as soon as a thin layer of liquid has formed in the contact area with the heat exchanger, can immediately float.

A design of the barrier elements to the effect that they form in the normal operation of the forming themselves on the plate surfaces ice plates in the Aufschwimmrichtung preferably uniform or increasingly expanding contour, favoring in this case, a fast self-dissolving and floating of the ice sheets and prevents tilting of the ice sheets between opposing barrier elements.

Further, it is advantageous that the barrier elements are designed such that they do not form a positive connection with the forming in the normal operation on the plate surfaces ice plates in a direction away from the respective plate surface of the heat exchanger.

It is preferred that the barrier elements are also designed such that they form in the intended operation on the plate surfaces ice plates in a direction away from the respective plate surface direction preferably uniformly or increasingly widening contour.

These measures favor a quick dissolution and floating of the ice plates and prevent tilting of the ice sheets between opposing barrier elements.

In a further preferred embodiment, the heat exchanger in addition to one or more barrier elements, which prevent the growing together of forming on the two plate surfaces ice plates in the range of the lower limits of the heat exchanger in the normal operation. While a growing together of forming on the two plate surfaces ice plates in the region of the lateral boundaries and the upper boundary of the heat exchanger for a quick detachment of the ice sheets is basically less problematic because this does not form a positive connection between the heat exchanger and the coalesced ice sheets in Aufschwimmrichtung is a The growing together of ice plates in the lower limits poses a problem in this respect and requires a great deal of heat energy for the removal of the ice plates, since the ice connecting the ice plates must be melted away before the ice sheets can float.

The barrier elements are preferably formed from sheet metal strips which protrude from one or both plate surfaces of the heat exchanger.

It is advantageous that the barrier elements forming sheet metal strips are in contact with actively participating in the heat exchange zones of the heat exchanger, preferably in surface contact with such zones, it is particularly advantageous if they are flat with these zones soldered and / or welded. This results in the advantage that in case of temporary heating of the heat exchanger surfaces in order to detach the ice sheets and the barrier elements are heated, which favors a quick detachment and floating of the ice sheets.

In yet another preferred embodiment of the heat exchanger, at least the lower limits of the heat exchanger during normal operation, preferably all boundaries of the heat exchanger, are formed by a zone with reduced heat exchange capacity, e.g. from a not flowed through with heat exchange medium edge region of the heat exchanger. In this way, it is possible to prevent the ice sheets forming on the plate surfaces from growing together around the boundaries during normal operation. As explained above, this is particularly critical in the lower limits, because here a positive connection between the coalesced ice sheets and the heat exchanger is created, which must be removed by melting away the ice plates connecting the ice before the ice sheets can float.

The supply and discharge for the heat exchanger medium are in accordance with the operation with advantage in the region of the lateral boundaries of the heat exchanger, it being preferred that the supply is arranged in the region of a first lateral boundary of the heat exchanger and the discharge in the area second, the first lateral boundary opposite lateral boundary of the heat exchanger.

The supply is preferably arranged in a lower region of the heat exchanger and the discharge in an upper region of the heat exchanger.

Such constructions have proven to be particularly practical.

In a further preferred embodiment of the heat exchanger, it is preferred that the supply and discharge of exactly one of the two plate surfaces of the heat exchanger protrude, preferably at an angle of 90 °. Such plate-shaped heat exchangers can be particularly easy and inexpensive to produce.

It is in such embodiments of the heat exchanger, in which the supply in the intended operation, the supply is arranged in the region of a first lateral boundary and the discharge in the region of a second, the first lateral boundary opposite lateral boundary is arranged, further preferred that the Barrier elements are designed such that they form in the normal operation by the forming on the plate surfaces ice plates in the plan view of the respective plate surface with respect to the vertical mirror-image limiting contours. As a result, the inclination of the floating ice sheets to tilt between the opposing barrier elements can be significantly reduced.

In another preferred embodiment of the heat exchanger, the discharge of a first of the two plate surfaces of the heat exchanger is away, preferably at an angle of 90 °, and is the supply of the other of the two plate surfaces of the heat exchanger away, also preferably at an angle of 90 °. Also, such plate-shaped heat exchanger can be produced particularly easily and inexpensively. However, they also have the advantage over the previously mentioned variant that only one barrier element is required per panel surface, so that a tilting of the ice sheets between two opposing barrier elements is possible.

Elements during floating is not possible and a quick dissolution and floating of the ice plates is favored as the barrier-element-free end of the ice plates peels off faster and then generated by its buoyancy leverage that accelerates detachment from the barrier element ,

In yet another preferred embodiment of the heat exchanger, the supply and discharge of the boundary of the heat exchanger are each in a direction parallel to the plate surfaces of the heat exchanger away. In such inventive heat exchangers, the removable ice sheets extend virtually over the entire exchanger surfaces, so that a particularly high exchange efficiency can be achieved.

A second aspect of the invention relates to an arrangement for the recovery of latent heat from water. The arrangement comprises a process zone flooded with water or floodable, in which one or more plate-shaped heat exchangers according to the first aspect of the invention are arranged with a substantially vertical orientation of their plate surfaces, such that the heat exchangers are arranged completely underneath the water level in the case of a process zone flooded with water as intended are. In this case, the process zone may be wholly or partially surrounded by boundaries, e.g. be formed by an open or closed process space or process container, or even without limitations, e.g. by having the heat exchangers in an open water such as e.g. in the sea, in a lake or in a watercourse are arranged.

The minimum distance of the upper limits of the heat exchanger to the water level in the process zone corresponds to the intended operation of the arrangement with advantage at least half of the maximum extent of the heat exchanger in the direction of gravity. This can be ensured at a technically reasonable distance between a plurality of arranged in a process zone heat exchangers that the ice sheets can easily float after detachment.

A third aspect of the invention relates to the use of the heat exchanger according to the first aspect of the invention or the arrangement according to the second aspect of the invention for recovering latent heat from water by means of a heat pump. In such uses, the advantages of the invention are particularly evident.

Further preferred embodiments of the invention will become apparent from the dependent claims and from the following description with reference to the figures. Showing:

1 is a perspective view of a first inventive heat exchanger:

Fig. 2a is a side view of the heat exchanger of Fig. 1;

Fig. 2b is a top plan view of the heat exchanger of Fig. 1;

Fig. 2c is a section along the line A-A in Fig. 2a;

3a shows a side view of a second heat exchanger according to the invention;

Fig. 3b is a top plan view of the heat exchanger of Fig. 3a;

4a shows a side view of a third heat exchanger according to the invention;

Fig. 4b is a top plan view of the heat exchanger of Fig. 4a;

5a shows a side view of a fourth heat exchanger according to the invention;

Fig. 5b is a top plan view of the heat exchanger of Fig. 5a;

6a shows a side view of a fifth heat exchanger according to the invention;

Fig. 6b is a top plan view of the heat exchanger of Fig. 6a;

7a shows a side view of a sixth heat exchanger according to the invention;

Fig. 7b is a top plan view of the heat exchanger of Fig. 7a;

8a shows a side view of a seventh heat exchanger according to the invention;

Fig. 8b is a top plan view of the heat exchanger of Fig. 8a;

9a shows a side view of an eighth heat exchanger according to the invention;

Fig. 9b is a top plan view of the heat exchanger of Fig. 9a; and

10 is a perspective view of an inventive arrangement with heat exchangers according to FIG. 1.

Fig. 1 shows a first inventive heat exchanger 1 for the recovery of latent heat from water in a perspective view in the intended vertical orientation. Figs. 2a and 2b show the heat exchanger 1 in the side view and in plan view from above.

As can be seen in conjunction with Fig. 2c, which shows a section along the line AA in Fig. 2a, the plate-shaped body of the heat exchanger 1 consists of two stainless steel plates, between which flow channels for the heat exchanger medium are formed and which in the edge region area soldered together and / or welded. In this way, a central, in the normal operation of the heat exchange medium M flowed through and thus actively involved in the heat exchange region 7 is formed, which is surrounded by a non-flow-through heat exchange medium edge zone 8, which thus does not or only slightly participate in the heat exchange. This edge zone 8 prevents the ice sheets forming on the plate surfaces 4a, 4b during normal operation from growing together around the boundaries of the heat exchanger 1.

The supply and discharge 2,3 for the heat exchanger medium M are arranged in the region of the two lateral boundaries of the heat exchanger 1, namely the supply 2 in the lower region of the left lateral boundary and the discharge 3 in the upper region of the right lateral boundary of the heat exchanger 1. They both stand away from the same plate surface 4a of the heat exchanger 1 at an angle of 90 °.

The inlet and outlet 2, 3 for the heat exchange medium M is in each case assigned a barrier element 5, 6, which is designed and arranged on the plate surface 4a, that there is a ingrowth of the intended operation on the plate surface 4a forming ice plate in the region of the respective inlet and outlet 2, 3 and in particular in the direction of gravity S seen under the respective supply and discharge 2, 3 area prevented.

The barrier elements 5, 6 form part of the forming on the plate surface 4a ice plate in the plan view of the plate surface 4a with respect to the vertical mirror-image limiting contours, which in the direction opposite to the direction of gravity S and in the direction perpendicular to the plate surface 4a increasingly pointing away, so that in these directions no positive connection between the forming on the plate surface 4a ice plate and the barrier elements 5, 6 can occur and tilting of the ice plate when loosening and floating is reliably prevented.

As can be seen in Fig. 2c, the barrier elements 5, 6 are formed by angled metal strips, which protrude from the plate surface 4a of the heat exchanger. They extend over the entire vertical extension of the heat exchanger 1 and are soldered and / or welded with their angled flange section 12 both in the region 7 actively participating in the heat exchange and in the edge zone 8 not flowed through with the heat exchanger medium on the plate-shaped body of the heat exchanger 1 (FIG. see Fig. 2c).

3a and 3b show a second inventive heat exchanger 1 in the side view and in plan view from above. This heat exchanger 1 differs from that shown in FIGS. 1 and 2a-2c only in that the feed element 2 associated barrier element 5 does not extend over the entire vertical extent of the heat exchanger 1, but only up to about half of this extension , wherein it is guided arcuately to the left lateral boundary of the heat exchanger 1.

4a and 4b show a third inventive heat exchanger 1 in the side view and in plan view from above. This heat exchanger 1 differs from that shown in Figs. 1 and 2a-2c only in that the feed 2 and the feeder 2 associated barrier element 5 mirror image of the arrangement shown in Figs. 1 and 2a-2c on the other plate surface 4b of the heat exchanger 1 are arranged.

5a and 5b show a fourth inventive heat exchanger 1 in the side view and in plan view from above. This heat exchanger 1 differs from that shown in Figs. 3a and 3b only in that the feed 2 and the feeder 2 associated barrier element 5 mirror image of the arrangement shown in Figs. 3a and 3b on the other plate surface 4b of Heat exchanger 1 are arranged.

6a and 6b show a fifth inventive heat exchanger 1 in the side view and in plan view from above. This heat exchanger 1 differs from that shown in Figs. 3a and 3b only in that the barrier elements 5, 6 are guided around the inlet and outlet 2, 3, such that their upper ends in the region of the lateral boundaries of the heat exchanger 1 pointing down.

7a and 7b show a sixth inventive heat exchanger 1 in the side view and in plan view from above. This heat exchanger 1 differs from that shown in FIGS. 6a and 6b in that the outlet 3 and the barrier element 3 associated with the outlet 3 are formed in mirror image with respect to the vertical to the feed 2 and its barrier element 5. The discharge 3 and its barrier element 6 are thus arranged in the lower region of the right lateral boundary of the heat exchanger 1.

8a and 8b show a seventh inventive heat exchanger 1 in the side view and in plan view from above. This heat exchanger 1 differs from the heat exchangers shown in the previous figures in that the supply 2 and the discharge 3 are arranged in the region of the left lateral boundary of the heat exchanger 1 and they share a common barrier element 5, which is rectilinear in vertical Direction extends over the heat exchanger 1. Another difference is that the inlet and outlet 2, 3 are designed as angled pipe sockets, which extend only a short distance perpendicular to the plate surface 4a and then parallel to this. All other design features are analogous to the heat exchangers 1 described above.

FIGS. 9a and 9b show an eighth heat exchanger 1 according to the invention in a side view and in a plan view from above.

Also in this heat exchanger 1, the plate-shaped body of the heat exchanger 1 consists of two stainless steel plates, between which 7 flow channels for the heat exchange medium M are formed in a central region. In a peripheral region 8 surrounding the central region 7, the sheet metal plates are soldered to one another in a planar manner and / or welded, their free ends 5, 6 diverging in the right and left edge regions. Between the gaping ends 5, 6 of the metal plates are the supply and discharge 2, 3 each in a direction parallel to the plate surfaces 4a, 4b of the heat exchanger 1 away from the lateral edge boundaries of the plate surfaces 4a, 4b of the heat exchanger 1, namely the supply 2 in the lower area of the left lateral edge boundary and the outlet 3 in the upper area of the right lateral edge boundary.

During normal operation, the central region 7 is flowed through by heat exchange medium M and is thus actively involved in the heat exchange, while the surrounding edge region 8 is not flowed through with heat exchange medium and thus not or only slightly participates in the heat exchange. This edge region 8 is designed to be relatively wide at the top and bottom and thus prevents the ice sheets forming on the plate surfaces 4a, 4b during normal operation from growing together around the upper and the lower boundary of the heat exchanger 1. In the side areas, the gaping free ends 5, 6 of the metal plates form barrier elements 5, 6, which prevent ingrowth of the ice plates forming on the plate surfaces 4a, 4b during normal operation into the regions of the supply and discharge 2, 3.

Fig. 10 shows a perspective view of an inventive arrangement for the recovery of latent heat from water W by means of a heat pump (not shown).

The arrangement comprises a process space 11 (the front and the right wall of the process space 11 are not shown) in which a process zone 9 flooded with water W is formed. In the process zone 9, five plate-shaped heat exchangers 1 according to FIGS. 1 and 2a-2c are arranged in a vertical orientation. The heat exchangers are arranged completely below the water level 10, wherein the minimum distance of the upper boundaries of the heat exchanger 1 to the water level 10 in the process zone 9 corresponds to approximately half the maximum extent of the heat exchanger 1 in the direction of gravity S.

While preferred embodiments of the invention are described in the present application, it should be clearly understood that the invention is not limited to these and may be practiced otherwise within the scope of the following claims.

Claims (21)

claims 1. Plate-shaped heat exchanger (1) for the recovery of latent heat from water (W), with a feed (2) and a discharge (3) for a heat exchange medium (M), by means of which in the normal operation in which the heat exchanger (1) is immersed in a substantially vertical orientation completely in water (W), the heat exchanger (1) surrounding the water (W) heat is removed, with the formation of ice on the two plate surfaces (4a, 4b) of the heat exchanger (1), characterized in that the heat exchanger (1) has one or more barrier elements (5, 6) which are designed in such a way that they cause the ice sheets forming in the intended operation on the plate surfaces (4a, 4b) to grow into areas which are located in the area intended operation in the direction of gravity (S) seen under the inlet and outlet (2, 3) are located, prevent. 2. Heat exchanger (1) according to claim 1, characterized in that the barrier elements (5,6) are designed such that they are a ingrowth of the on the plate surfaces (4a, 4b) forming ice sheets in the areas of the supply and Prevent discharge (2, 3). 3. Heat exchanger (1) according to one of the preceding claims, characterized in that the barrier elements (5, 6) are designed such that they in the normal operation in a direction opposite to the direction of gravity (S) no positive connection with the on the Form plate surfaces (4a, 4b) forming ice sheets. 4. Heat exchanger (1) according to claim 3, characterized in that the barrier elements (5,6) are designed such that they in the normal operation by the on the plate surfaces (4a, 4b) forming ice sheets in the direction against the direction of gravity (S) form expanding contour. 5. Heat exchanger (1) according to any one of the preceding claims, characterized in that the barrier elements (5,6) are formed such that they pointing in a direction substantially perpendicularly away from the respective plate surface (4a, 4b) no positive connection with form in the normal operation on the plate surfaces (4a, 4b) forming ice sheets. 6. Heat exchanger (1) according to claim 5, characterized in that the barrier elements (5,6) are designed such that they form part of the in normal operation on the plate surfaces (4a, 4b) forming ice sheets in the of form the expanding direction of the respective plate surface (4a, 4b) direction. 7. Heat exchanger (1) according to any one of claims 4 and 6, characterized in that the barrier elements (5, 6) are formed such that the part of them in the normal operation on the plate surfaces (4a, 4b) forming ice plate formed, expanding contour evenly or increasingly expanded. 8. Heat exchanger according to one of the preceding claims, characterized in that the heat exchanger additionally comprises one or more barrier elements, which prevent the growing together of forming on the two plate surfaces ice plates in the range of the lower limits of the heat exchanger in the normal operation. 9. Heat exchanger (1) according to one of the preceding claims, characterized in that the barrier elements (5, 6) and optionally the additional barrier elements of sheet metal strips are formed, which of one or both plate surfaces (4a, 4b) of the Heat exchanger stand out. 10. Heat exchanger (1) according to claim 9, characterized in that the metal strips are in contact with the heat exchange involved in the zones (7) of the heat exchanger, in particular in surface contact with these zones (7) are, and in particular that they are with these zones (7) are soldered flat and / or welded. 11. Heat exchanger (1) according to one of the preceding claims, characterized in that at least the lower limits of the heat exchanger (1), in particular all limitations of the heat exchanger (1), are formed by a zone (8) with reduced heat exchange capacity during normal operation, in particular of an edge region (8) of the heat exchanger (1) through which no heat exchange medium (M) flows, which prevents the ice plates forming on the plate surfaces (4a, 4b) from growing together around the boundaries of the heat exchanger (1) during normal operation. 12. Heat exchanger (1) according to one of the preceding claims, characterized in that in the intended operation, the inlet and outlet (2, 3) in the region of the lateral boundaries of the heat exchanger (1) are arranged, and in particular that the feed (2 ) is arranged in the region of a first lateral boundary of the heat exchanger and the discharge (3) in the region of a second, the first lateral boundary opposite the lateral boundary of the heat exchanger (1) is arranged. 13. Heat exchanger (1) according to claim 12, characterized in that in the intended operation, the supply (2) in a lower region of the heat exchanger (1) is arranged and the discharge (3) in an upper region of the heat exchanger (1) is arranged , 14. Heat exchanger (1) according to one of the preceding claims, characterized in that the inlet and outlet (2, 3) of exactly one (4a) of the two plate surfaces (4a, 4b) of the heat exchanger (1) protrude, in particular under a Angle of 90 °. 15. Heat exchanger (1) according to one of claims 12 to 13 and according to claim 14, wherein in the intended operation, the supply (2) is arranged in the region of a first lateral boundary and the discharge (3) in the region of a second, the first lateral boundary is arranged opposite lateral boundary, characterized in that the barrier elements (5, 6) are designed such that they in the normal operation by the on the plate surface (4a) forming the ice plate in the plan view of the plate surface (4a) with respect form the vertical mirror image boundary contours. 16. Heat exchanger (1) according to one of claims 1 to 13, characterized in that the discharge (3) from a first (4a) of the two plate surfaces (4a, 4b) of the heat exchanger (1) protrudes, in particular at an angle of 90 °, and that the feed (2) from the other (4b) of the two plate surfaces (4a, 4b) of the heat exchanger (1) protrudes, in particular at an angle of 90 °. 17. Heat exchanger (1) according to one of claims 1 to 13, characterized in that the inlet and outlet (2, 3) of the boundary of the heat exchanger (1) in each case in a direction parallel to the plate surfaces (4a, 4b) of Heat exchanger stand out. 18. Arrangement for obtaining latent heat from water (W), comprising a process zone (9) flooded or flooded with water (W), in which one or more plate-shaped heat exchangers (1) according to one of the preceding claims are arranged with a substantially vertical orientation are such that the heat exchangers (1) are arranged completely below the water level (10) in the case of a process zone (9) flooded with water as intended. 19. Arrangement according to claim 18, characterized in that the process zone (9) is formed by a closed process space (11) or process container. 20. The arrangement according to one of claims 18 to 19, characterized in that in the normal operation of the arrangement, the minimum distance of the upper boundaries of the heat exchanger (1) to the water level (10) in the process zone (9) at least half of the maximum extent of the heat exchanger (1) in the direction of gravity (S). 21. Use of the heat exchanger (1) according to any one of claims 1 to 17 or the arrangement according to one of claims 18 to 20 for the recovery of latent heat from water (W) by means of a heat pump.