WO2001057452A1

WO2001057452A1 - Heater and/or cooler

Info

Publication number: WO2001057452A1
Application number: PCT/SE2001/000172
Authority: WO
Inventors: Pontus BÜLOW NIELSEN; Ralf Blomgren; Martin Holm; Mats Nilsson
Original assignee: Alfa Laval Corporate Ab.
Priority date: 2000-02-01
Filing date: 2001-01-30
Publication date: 2001-08-09
Also published as: EP1252470A1; SE0000336L; SE0000336D0; SE518190C2; DE60109418D1; AU2001230694A1; ATE291204T1; EP1252470B1

Abstract

The present invention concerns a heater and/or cooler comprising at least one tank (2) with at least one inner space (3) and at least one plate heat exchanger (4a, 4b) for at least two heat exchanging fluids, which heat exchanger (4a, 4b) is permanently joined and comprises at least one core of plates with a plurality of heat exchanging plates (5a, 5b) and at least two end plates (6a, 6b, 7a, 7b), the heat exchanging plates (5a, 5b) creating plate interspaces between each other. Each one of the heat exchanging plates (5a, 5b) is provided with one or several corrugations and at least two port holes being parts of at least one inlet channel (10a, 10b) and at least one outlet channel (11a, 11b), respectively, through the core of plates for at least one of the fluids, a first inlet channel (10a, 10b) and a first outlet channel (11a, 11b) being intended for a first fluid and being in fluid communication with a first set of plate interspaces. The said at least one plat heat exchanger (4a, 4b) is housed in the said at least one tank (2), a second set of plate interspaces being in fluid communication with the said at least one inner space (3) in the said at least one tank (2).

Description

Heater and/or cooler

The present invention concerns a heater and/or cooler comprising at least one tank with at least one inner space and at least one plate heat exchanger for at least two heat exchanging fluids, which plate heat exchanger is permanently joined and comprises at least one core of plates with a plurality of heat exchanging plates and at least two end plates, the heat exchanging plates creating plate interspaces between each other.

Prior art

EP.A2 0 905 453 shows a water heater which in addition to a primary heat exchanger heated by a heat source also comprises a secondary heat exchanger and a hot water storage. The hot water storage is in close thermal contact with heat exchanging plates in the secondary heat exchanger and is built together with this. The described modes of execution of the hot water storage is, however, not at optimum concerning heat transfer, strength, material consumption etc.

Summary of the invention

The purpose of the invention is to provide a heater for heating of water of such a kind that hot water may be provided directly at tapping even after a longer period of standstill without any need for hot water. The purpose of the invention is also, as a consequence of the just said, to create a heater or cooler for heating or cooling of any convenient fluid at all so that such a heated or cooled fluid may be provided directly even after a longer period without any need for in such a way heated or cooled fluid. At the same time the heat transfer between the working fluids in the heater and/or cooler shall be good under all service conditions, the strength characteristics be good for both the tank of the heater and/or cooler and for single plates in the core of plates and the material consumption be small.

The invention thus comprises a heater and/or cooler comprising at least one tank with at least one inner space and at least one plate heat exchanger for at least two heat exchanging fluids, which plate heat exchanger is permanently joined and comprises at least one core of plates with a plurality of heat exchanging plates and at least two end plates, the heat exchanging plates creating plate interspaces between each other.

Each one of the heat exchanging plates is provided with one or several corrugations vertically extending within an area delimited by two at a distance from each other situated parallel first and second planes, respectively, and which both are mainly in parallel with all the heat exchanging plates as well as the end plates of the plate heat exchanger. Each one of the heat exchanging plates is provided with at least two port holes being parts of at least one inlet channel and at least one outlet channel, respectively, through the core of plates for at least one of the fluids, a first inlet channel and a first outlet channel being aimed for a first fluid.

The end plates together have at least two port holes communicating with the said at least one inlet channel and the said at least one outlet channel, respectively. The said first inlet channel and the said first outlet channel are in fluid communication with a first set of plate interspaces. The said at least one plate heat exchanger is housed in the said at least one tank, a second set of plate interspaces being in fluid communication with the said at least one inner space in the said at least one tank.

The characteristics in other respects of the present invention are clear from the following patent claims.

The heater and/or cooler will now be closer described in connection with forms of execution of the invention and with reference to the accom- panying drawings.

List of drawings

Figure 1 shows, in a perspective view and partly in cross section, a heater and/or cooler according to the invention.

Figure 2 shows in a front view an alternative mode of execution of a heater and/or cooler according to the invention.

Figure 3 shows a cross section through the heater and/or cooler along the line A-A in figure 2.

Figure 4 shows a cross section through the heater and/or cooler along the line B-B in figure 2.

Figure 5 shows a cross section through the heater and/or cooler along the line C-C in figure 2.

Figure 6 shows a cross section through the heater and/or cooler along the line D-D in figure 2. Figure 7 shows a cross section through the heater and/or cooler along the line E-E in figure 2.

Figure 8 shows in a view from above the heater and/or cooler in figure 2.

Description of modes of execution

The heater and/or cooler 1 in figure 1 , aimed for heating of tap hot water, consists of a tank 2 with an inner space 3 housing two plate heat exchangers 4a, 4b. The plate heat exchanger 4a comprises a core of plates with a plurality of heat exchanging plates 5a and two end plates 6a, 7a. In a corresponding way the plate heat exchanger 4b comprises a core of plates with a plurality of heat exchanging plates 5b and two end plates 6b, 7b.

Each one of the two front (the two nearer ones in the figure) end plates 6a, 6b shows two connections 8a, 9a and 8b, 9b, respectively, of which at least two connections 8a, 9b extend fluidum tightly through the front wall of the tank 2 while the other two connections 8b, 9a are fluidum tightly connected to one another through an outward pressing (not shown) in the tank 2, which outward pressing has the same function as a U-formed piece of pipe and fluidum tightly connects the connections 8b and 9a in that the plate heat exchangers 4a, 4b seal against the partition wall 14 within the area for the said outward pressing and seals against the tank 2 around the said outward pressing. A construction without the outward pressing is thinkable, whereby a U-formed piece of pipe instead extends fluidum tightly through the front (the nearer one in the figure) wall of the tank 2 or through the partition wall 14. The plate heat exchangers 4a, 4b then do not need to seal completely against the partition wall 14 or against the tank 2. With fluidum tightly in this connection is meant that the fluid, in this case hot water or hot steam, which is led through the described connections do not mix with the fluid, in this case water to be heated, which is present within the tank.

The connection 8a leads to an inlet channel 10a and the connection 9a leads from an outlet channel 11 a in the plate heat exchanger 4a. In a corresponding way the connection 8b leads to an inlet channel 10b and the connection 9b from an outlet channel 1 1 b in the plate heat exchanger 4b. The inlet channel 10a and the outlet channel 1 1 a are in fluid communication with a first set of plate interspaces in the plate heat exchanger 4a. In a corresponding way the inlet channel 10b and the outlet channel 11 b are in fluid communication with a first set of plate interspaces in the plate heat exchanger 4b. The mentioned first sets of plate interspaces are constituted by every other plate interspace between the heat exchanging plates 5a, 5b in the plate heat exchangers 4a, 4b respectively.

Further two connections 12, 13 (due to the cross section only hinted in figure 1 ) extend through the front wall of the tank 2 in order to make delivery to and removal from the tank, respectively, possible of the fluid which is present there. The inner space 3 in the tank 2 is in fluid communication with a second set of plate interspaces in each one of the two plate heat exchangers 4a, 4b. In the present case all the plate inter- spaces which are not part of the described first sets of plate interspaces according to above are parts of the described second sets of plate interspaces, i.e. also the present interspaces between each one of the end plates 6a, 6b, 7a, 7b and the closest situated heat exchanging plate 5a, 5b, respectively. A partition wall 14 divides the inner space 3 into two part spaces which, however, are in fluid communication with each other in the upper part of the tank 2. The tank 2 is rectangular and its height is larger than its width or depth. The tank 2 is executed of steel panel but any other known suitable material at all may be used.

From the figures 2-8 an alternative mode of execution of the described heater and/or cooler is evident, whereby the reference signs from figure 1 have been kept. The tank 2 is here constituted by four, in using the heater and/or cooler mainly vertical, hollow cylinders 18 which in the upper part of the heater and/or cooler are in fluid communication with a, in using the heater and/or cooler mainly horizontal, hollow cylinder 19 and in the lower part of the heater and/or cooler are in fluid communication with a, in using the heater and/or cooler mainly horizontally extending hollow space 20 housing two plate heat exchangers 4a, 4b.

Since the tank 2 basically is constructed by two pressed panels, a front one creating the front side of the heater and/or cooler, see figure 2, and a back one with the corresponding appearance but without connections, the panels must be fluidum tightly joined around the outer edges and mainly fluidum tightly joined between the described hollow cylinders 18, see figure 3. Even if it is more important that the panels are fluidum tightly joined between the two middle hollow cylinders 18 than between the rest of the hollow cylinders 18 still a certain minor leakage may be generally allowed between the cylinders 18. The partition wall 14 needs not to be higher than what corresponds to the height of the hollow space 20, see figure 5.

An outward pressing 21 , see figure 2, has the same function as a U- formed piece of pipe and fluidum tightly connects the connections 8b and 9a in that the plate heat exchangers 4a, 4b seal against the partition wall 14 in the area for the said outward pressing 21 and seal against the tank 2 around the said outward pressing 21. A construction without any outward pressing 21 is thinkable whereby a U-formed piece of pipe instead extends fluidum tightly through the front ( the one nearer in figure 2) wall on the tank 2. The plate heat exchangers 4a, 4b then do not have to seal completely against the partition wall 14 or against the tank 2. Further there are present a temperature sensor 22, an aeration nipple 23 and four suspension holes 24.

The function of the heater and/or cooler, which in principle is the same for the two modes of execution, will now be closer described. Hot water or hot steam (see the continuous line 15 in figure 1 ) from a heat source not shown here enters the heater and/or cooler through the connection 8a, continues into the inlet channel 10a in the plate heat exchanger 4a and is divided within the first set of plate interspaces in this plate heat exchanger, passes through the plate interspaces (the line 15 marks for the sake of clearness one plate interspace only), continues out through the outlet channel 11 a and the connection 9a, continues to and through the connection 8b, continues into the inlet channel 10b in the plate heat exchanger 4b and is divided within the first set of plate interspaces in this plate heat exchanger, passes through the plate interspaces (the line 15 marks for the sake of clearness one plate interspace only), continues out through the outlet channel 11b and exits through the connection 9b, after which the water or the steam returns to the heat source for a new heating.

The tap water (see the continuous line 16 in figure 1 ) enters the heater and/or cooler through the connection 12 and exits through the connection 13. The tap water may freely move within the second sets of plate interspaces. Due to the presence of the partition wall 14 the tap water will preferably move upwards in the right part of the inner space 3 and down- wards in the left part of the same space. Over this main direction for the flow of tap water those water movements which are caused by the heating of the tap water within the plate interspaces are added. By a suitable control (not shown) a suitable temperature of the tap water which leaves the heater for use as water for showering or the like is held.

Also during periods with little or no tapping of hot water hot water or hot steam is, at least intermittently, delivered to the two in series coupled plate heat exchangers 4a, 4b. In this way it is secured that the volume of tap water within the tank 2 and the inner space 3 due to a self circulation (see the broken lines 17 in figure 1 ) at all times is held at a convenient level of temperature for showering or the like. This heated water volume comes practically at once out of the heat exchanger when tapping is once again started and the volume is so adapted that the heat exchanger reaches service performance in a steady condition before the previously stored water is finished.

Compared to prior art the construction shows the considerate advantage that the previously heated water volume discussed in the previous section is large enough. If the thickness of the plate in the tank is held down the manufacturing costs will become small, which is possible with the mode of execution according to the figures 2-8 since the strength of the construction is sufficiently good in spite of the use of a thin panel. Since every heat exchanging plate in the plate heat exchangers only has two port holes a larger part of the areas of the plates may be used for heat exchange than had otherwise been the case. The present corrugation pattern on the plates may also be of a simple kind.

The plates are often made of steel plate with a thickness of 0,20-0,35 mm, but also other materials may be used such as for example titanium. The heat exchanging plates are often thin and the end plates thick, but also other modes of execution may exist. For example it is possible to think of the end plates not being thick but instead being of an appearance totally or partly in accordance with the present heat exchanging plates, however with the difference that port holes only are present where the mounting of connections are desired. One may also think of using end plates of different designs in different ends of the present core of plates or even more end plates of the same or different appearances in each one of the ends of the present core of plates.

The present core of plates may be permanently joined in any convenient known way, for instance by brazing, welding or gluing. When brazing the core of plates together copper braze, nickel braze or any other known braze may be used. In using the heater and/or cooler one or several of the fluids may be something else than water. For example it is possible to think of heat exchange between oil and water. Further on one or several of the fluids may move in another direction through the heater and/or cooler than has been described above. Thus, the flow direction may be reversed for the said first fluid or for the said second fluid or for the said first and second fluids at the same time.

The invention is not restricted to the forms of execution shown here but may be varied in accordance with the following patent claims.

Claims

1. Heater and/or cooler comprising at least one tank (2) with at least one inner space (3) and at least one plate heat exchanger (4a, 4b) for at least two heat exchanging fluids, which plate heat exchanger (4a, 4b) is permanently joined and comprises at least one core of plates with a plurality of heat exchanging plates (5a, 5b) and at least two end plates (6a, 6b, 7a, 7b) the heat exchanging plates (5a, 5b) creating plate interspaces between each other and at which

each one of the heat exchanging plates (5a, 5b) is provided with one or several corrugations vertically extending within an area bounded by two at a distance to each other situated parallel first and second planes, respectively, and which both are mainly in parallel with all the heat exchanging plates (5a, 5b) as well as the end plates (6a, 6b, 7a, 7b) of the plate heat exchanger,

each one of the heat exchanging plates (5a, 5b) is provided with at least two port holes being parts of at least one inlet channel (10a, 10b) and at least one outlet channel (11 a, 11 b) through the core of plates, respectively, for at least one of the fluids, a first inlet channel (10a, 10b) and a first outlet channel (11a, 11 b) being intended for a first fluid,

the end plates (6a, 6b, 7a, 7b) together have at least two port holes communicating with the said at least one inlet channel (10a, 10b) and the said at least one outlet channel (11 a, 11 b) respectively, and

the said first inlet channel (10a, 10b) and the said first outlet channel (1 1 a, 11 b) are in fluid communication with a first set of plate interspaces, c h a r a c t e r i z e d i n that

the said at least one plate heat exchanger (4a, 4b) is housed in the said at least one tank (2), a second set of plate interspaces being in fluid communication with the said at least one inner space (3) in the said at least one tank (2).

2. Heater and/or cooler according to claim 1 , at which the said first set of plate interspaces is constituted by every other plate interspace in the said at least one plate heat exchanger (4a, 4b).

3. Heater and/or cooler according to claim 2, at which the said second set of plate interspaces is constituted by the remaining plate interspaces in the said at least one plate heat exchanger (4a, 4b).

4. Heater and/or cooler according to claim 3, at which the said second set of plate interspaces also comprises at least one of the present interspaces between each one of the end plates (6a, 6b, 7a, 7b) and the closest situated heat exchanging plate (5a, 5b), respectively.

5. Heater and/or cooler according to any of the preceding claims at which the said at least one tank (2) contains a second fluid.

6. Heater and/or cooler according to any of the preceding claims, at which a first connection (8a) through a first wall on the said at least one tank (2) is present to the said first inlet channel (10a) and a second connection (9b) through the said first wall on the said at least one tank (2) is present from the said first outlet channel (11 b) in the said at least one plate heat exchanger (4a, 4b), for the said first fluid.

7. Heater and/or cooler according to any of the preceding claims at which two connections (12, 13) through a first wail on the said at least one tank (2) are present to and from the said at least one inner space (3), respectively, in the said at least one tank (2) for the said second fluid.

8. Heater and/or cooler according to any of the preceding claims, at which at least two plate heat exchangers are housed in the said at least one tank (2), a second set of plate interspaces in each one of them being in fluid communication with the said at least one inner space (3) in the said at least one tank (2).

9. Heater and/or cooler according to claim 8, at which at least one partition wall (14) divides the said at least one inner space (3) into part spaces in such a way that each one of the said part spaces shows at least one of the said plate heat exchangers (4a, 4b).

10. Heater and/or cooler according to claim 9, at which the said part spaces are in fluid communication with each other, whereby fluid may be freely exchanged between the part spaces within the upper part of the tank (2).

11. Heater and/or cooler according to claim 10, at which the said part spaces are mainly of the same size.

12. Heater and/or cooler according to any of the claims 8-11 , at which the said first outlet channel (11a) for a first one of the said plate heat exchangers (4a) is connected to the said first inlet channel (10b) for a second one of said plate heat exchangers (4b) so that the said first fluid may enter the said first inlet channel (10a) in the said first plate heat exchanger (4a) via a first connection (8a) through a first wall on the said at least one tank (2), pass through the said two in series connected plate heat exchangers (4a, 4b) and after that exit from the said first outlet channel (11 b) in the said second plate heat exchanger (4b) via a second connection (9b) through the said first wall upon the said at least one tank (2).

13. Heater and/or cooler according any of the preceding claims, at which the said tank (2) is mainly of a rectangular form.

14. Heater and/or cooler according to any of the claims 1 -12, at which the said tank (2) is constituted by at least two, in use of the heater and/or cooler mainly vertical, hollow cylinders (18) which in the upper part of the heater and/or cooler are in fluid communication with a, in using the heater and/or cooler mainly horizontal, hollow cylinder (19) and in the lower part of the heater and/or cooler are in fluid communication with a, in using the heater and/or cooler mainly horizontally extending hollow space (20) housing the said plate heat exchanger (4a, 4b).

15. Heater and/or cooler according to any of the preceding claims, at which the height of the tank (2) is larger than its width or depth.