WO2007003193A1

WO2007003193A1 - Heat exchanger

Info

Publication number: WO2007003193A1
Application number: PCT/DK2006/000386
Authority: WO
Inventors: Urh Hudoklin
Original assignee: Danfoss A/S
Priority date: 2005-07-02
Filing date: 2006-06-30
Publication date: 2007-01-11
Also published as: ATE429624T1; EP1902268B1; DE502006003550D1; RU2363904C1; EP1902268A1; CN101258377A; CN101258377B; DE102005031026B3; DK1902268T3

Abstract

The invention relates to a heat exchanger (1, 25, 35, 37) comprising a housing (2), with a primary inlet connector (3), a primary outlet connector (4), a secondary inlet connector (5), a secondary outlet connector (6), a primary flow path (7) between the primary inlet connector (3) and the primary outlet connector (4) on a primary side (8), a secondary flow path (9) between the secondary inlet connector (5) and the secondary outlet connector (6) on a secondary side (10), the primary flow path (7) being in heat-transferring connection to the secondary flow path (9). The heat exchanger (1, 25, 35, 37) comprises at least one control auxiliary device, arranged in the primary flow path (7) and the secondary flow path (9). A constructive improvement to the heat exchanger is desirable which is achieved by means of running the control auxiliary device through a cavity (20), arranged between the primary flow path (7) and the secondary flow path (9).

Description

heat exchangers

The invention relates to a heat exchanger with a housing having a primary inlet port, a primary outlet port, a secondary inlet port and a secondary outlet port, wherein between the primary inlet port and the primary outlet port a primary primary side flow path and between the secondary inlet port and the second outlet port secondary outlet port a secondary secondary side flow path is arranged, wherein the primary flow path with the secondary flow path in heat transferring connection and the heat exchanger has at least one control auxiliary device which is arranged in the primary flow path and in the secondary flow path.

Such a heat exchanger is known for example from EP 608 195 B1. Within a housing of the known heat exchanger, a temperature sensor is integrated and measures both the temperature in the primary and secondary flow path. The temperature sensor is located in a cylindrical tube and is in communication with a valve outside the housing.

Heat exchangers are used to transfer thermal energy from a primary medium to a secondary medium without mixing the two media. Here, for example, the first medium water of a district heating system and the second medium water in drinking water quality. Also, at least one medium may be gas. In order to reduce the dimensions of the heat exchanger, auxiliary control devices, such as, for example, sensors, which are required for the operation of the heat exchanger, are integrated in the heat exchanger. As a result, however, vulnerabilities are created inside the heat exchanger. If control auxiliary devices, such as sensors, are integrated in a heat exchanger and are arranged in two separate flow paths at the same time, then interfaces are created at the openings from one flow path to the other flow path. There is thus the possibility that the two media come into contact with each other and mix inadvertently. This happens, for example, if one of the interfaces leaks.

The invention has the object to improve a heat exchanger constructive.

This object is achieved in a heat exchanger of the type mentioned in that the control auxiliary device is passed through a gap which is arranged between the primary flow path and the secondary flow path.

The transition regions, and thus the interfaces between the primary flow path and the secondary flow path, are isolated from one another by the primary flow path and the secondary flow path each adjoining the intermediate space. The gap is then between the primary and the secondary side of the heat exchanger. This applies at least to the part of the heat exchanger in which the control auxiliary device is arranged in the primary flow path and in the secondary flow path. The primary and secondary flow paths are spaced apart in this part of the heat exchanger. The auxiliary control device is guided through the intermediate space and is thus arranged simultaneously in three areas, namely in the intermediate space and in the areas to the right and left of

Gap. Control aids are here, for example used for controlling or regulating the heat exchanger and act, for example, mechanically or thermally. Also, electrical cables are conceivable, which are guided to a device within the heat exchanger. Should a seal between the primary flow path and the intermediate space or between the secondary flow path and the interspace be leaking, the interspace serves as a location for leakages. Accordingly, fluid which leaves the primary or secondary flow path unintentionally arrives at a defined location. This prevents major damage to the heat exchanger. It is also ensured by the gap that not the fluids of the primary and secondary sides come into contact with each other. Namely, it is unlikely that the interface between the primary flow path and the gap and the interface between the secondary flow path and the gap become leaking at the same time. By trapping leaks in the space, the operation of the heat exchanger is safer and more reliable. In the intermediate space, for example, a monitoring sensor can be arranged, which detects an entry of the fluid into the intermediate space. Thereupon, further measures can be initiated which prevent a major leakage, for example the shut-off of the inlet and outlet lines.

It is particularly preferred that the gap communicates with an environment of the housing. In this way, the intermediate space can have a small volume. The volume of the gap can then be designed only for small amounts of leakage, as in case of failure, fluid can be passed on to the outside. The heat exchanger is not significantly larger by the gap than a heat exchanger without this gap. If fluid penetrates into the intermediate space, this can evaporate, for example because of its heat and through the adjacent heated primary and secondary sides. It For example, leaks occur when the fluid in the primary line rises to higher temperatures than intended. The fluid then expands due to the elevated temperature and requires more space. At a weak point, such as a seal, the fluid tries to escape. It gives the fluid with the arrangement of the intermediate space a predetermined breaking point. The intermediate space absorbs the fluid and at the same time reduces the overpressure caused by the fluid. The intermediate area relieves the remaining areas of the heat exchanger by the gap is in communication with the environment of the housing, so that an overpressure can escape. Although some fluid is then lost, but there is no longer any danger that other areas of the heat exchanger are affected by a pressure increase.

Preferably, the gap is at least partially bounded by the housing. The housing thus encloses at least a portion of the primary and a portion of the secondary flow path and the space. For example, the gap may be bounded by the walls of the primary and secondary flow paths on its other walls, which are not formed by the housing. It is therefore provided without a lot of material, the gap.

It is particularly preferred that the intermediate space has at least one opening which is arranged in the housing. The intermediate space thus directly adjoins the housing and has at least one opening which connects the intermediate space with the environment to the outside. There are thus no channels necessary, which could hinder the drainage or evaporation of leaked fluid.

It is preferred that the control auxiliary device is a first valve tappet of a first valve. The first valve is thus a cartridge valve, since it is at least partially disposed within the heat exchanger. On This way one achieves a compact design of the heat exchanger. In this case, the first valve tappet is arranged simultaneously in at least one actuation position in the primary and secondary flow paths as well as in the intermediate region.

According to a preferred embodiment of the invention, the first valve is arranged in the region of the secondary inlet port. The valve is inserted, for example, at the secondary inlet port from the outside into the housing of the heat exchanger and connected against falling out by a screw connection to the housing. The first valve is thus easily replaceable and sufficiently fixed at a resulting overpressure of the fluid. Also, the first valve is thermally stressed, since on the secondary side of the heat exchanger, the fluid is heated by the fluid of the primary side and the fluid at the secondary inlet port has a lower temperature than the secondary outlet port.

It is preferred that the primary inlet port comprises a first valve seat of the first valve. It is thus possible to control the inflow of the fluid in the primary inlet port with the first valve. This is particularly easy when the primary inlet port and the secondary

Outlet port are arranged opposite and the connections are on a straight line connection. For example, the first valve seat is fixed to the housing arranged in the primary inlet port and seals at the same time with the first valve closed the primary inlet connection from. A first valve member of the first valve which cooperates with the valve seat is conveniently flowable through the primary inlet port.

Conveniently, the first valve has a membrane that comes into contact with fluid of the secondary flow path. A membrane responds almost inertia to set pressure changes in the second secondary inlet connection. Accordingly, the first valve has a short reaction time.

Preferably, the first valve stem with the membrane is actuated. It thus uses the almost inertia-free response of the membrane for the valve lifter. Thus, one can influence the fluid flow in the primary flow path without delay in dependence on the fluid flow in the secondary flow path.

Preferably, the control auxiliary device is a temperature sensor. For safe operation of the heat exchanger, it is advantageous to also measure the temperature of the fluid inside the heat exchanger. You then have the opportunity to make the heat exchanger safer due to a measured temperature. This happens, for example, by monitoring a fluid temperature in the heat exchanger. At too high a temperature of the fluid, measures are taken to protect a user from burns. Also, the room conditions of the heat exchanger is effectively used by an integrated temperature sensor inside the housing.

Preferably, the temperature sensor communicates with the gap via a fluid path. The temperature sensor may, for example, use the gap as reference point for temperature measurement. The temperature sensor may also extend into the intermediate space during a thermal expansion. In this way, no additional space is needed in a warming and prevents a pressure increase due to a material expansion of the temperature sensor. The gap can also serve to equalize the pressure.

It is provided that the temperature sensor has a bellows, wherein the interior of the bellows is delimited from a sensor space and the internal the bellows is in communication with the gap. The bellows is a moving part of the temperature sensor that changes in geometry due to temperature changes. By connecting the interior of the bellows to the intermediate space, the geometry of the movable bellows is effected exclusively by the temperature of an expansible material in the sensor space. In contrast to the interior of the bellows, the sensor space has no connection to another room and is closed. With this configuration, the measurement with the temperature sensor can be made independent of an influence of the primary or secondary flow path, although the temperature sensor is arranged simultaneously in both flow paths and these flow paths usually have different temperatures.

It is particularly preferred that the temperature sensor is in communication with a second valve stem of a second valve. The temperature sensor can thus act directly on a second valve. The second valve lifter is at least partially disposed within the housing. This ensures that the movement space of the second valve stem is independent of external geometries of the second valve.

It is envisaged that the second valve is arranged in the region of the primary outlet port. In the primary outlet port, the primary side fluid has a lower temperature than the primary inlet port. The thermal load of the second valve is kept so low. If the primary outlet port is arranged opposite to the secondary outlet port, then it is possible in a simple manner to actuate the second valve as a function of the measured temperature in the secondary connection region. Bθ vorzugterweise, the second valve has a return spring which presses a valve element against a second valve seat, thereby closing the primary outlet port. The return spring causes a counterforce to the force that is generated by the inflowing fluid of the primary flow path to the valve element. If the counterforce of the return spring is overcome, then the second valve is in the open position. The opposing force of the return spring is adjustable, so that you can adjust the second valve to different operating conditions.

It is particularly preferred that the heat exchanger has heat exchanger plates, wherein in a first region the primary and secondary flow paths are arranged parallel to one another and in a second region the primary and secondary flow paths are arranged diagonally to one another. In this arrangement of the flow paths, it is possible to simultaneously operate an integrated temperature sensor, a first and a second valve, which are each arranged at least partially within the housing. For this purpose, it is provided that the primary inlet port is arranged opposite the secondary inlet port and at the same time the primary outlet port is arranged opposite the secondary outlet port. The higher the number of heat exchanger plates, the more heat the heat exchanger can deliver at the same time. This is for example advantageous if the heat exchanger is provided for a space heating system.

The invention will be described in more detail below with reference to preferred embodiments in conjunction with the drawings. Herein show:

Fig. 1 is a schematic sectional view of a

Heat exchanger with a first valve, Fig. 2 is a schematic sectional view of a

Heat exchanger with an integrated

Temperature sensor,

Fig. 3 is a schematic view of a heat exchanger with a plurality of heat exchanger plates and

Fig. 4 shows an embodiment in sectional view of a heat exchanger with a first valve and an integrated temperature sensor, which cooperates with a second valve.

Fig. 1 shows schematically a sectional view of a heat exchanger 1 with a housing 2 having a primary inlet port 3, a primary outlet port 4, a secondary inlet port 5 and a secondary outlet port 6. Between the primary inlet port 3 and the primary outlet port 4, a primary flow path 7 of a primary side 8 and between the secondary inlet port 5 and the secondary outlet port 6 is a secondary flow path

9 a secondary side 10 is arranged. In the sectional view of FIG. 1, the flow paths 7,9 are only partially visible. The flow direction is represented by arrows 11. The primary side fluid 8 enters at the primary inlet port 3 and exits at the primary outlet port 4. The secondary side fluid 10 enters the secondary inlet port 5 and the secondary outlet port 6 accordingly. Inside the heat exchanger 1, the fluid of the primary side 8 gives off heat to the fluid of the secondary side 10, so that the fluid of the secondary side 10 is heated. Consequently, the fluid of the primary side 8 at the primary inlet port 3 is warmer than at the primary outlet port 4. The fluid of the secondary side

10 is colder at the secondary inlet port 5 than at the secondary outlet port 6. The heat exchanger 1 in FIG. 1 has a first region 12, a second region 13 and a third region 14. The first region 12 extends from the side of the housing 2 to the primary outlet port 4 and the secondary inlet port 5 to the third region 14. The second region 13 extends from the side of the housing 2 to the primary inlet port 3 and the secondary outlet port 6 to the third region 14. A first valve stem 15 extends from the secondary flow path 9 in the first region 12 via the third region 14 in the primary flow path 7 in the second region 13. The first tappet valve 15 is part of a first valve 16, the secondary inlet port 5 is arranged and extends partially into the interior of the housing 2. The first valve 16 is a cartridge valve having a diaphragm 17 acting on the first valve lifter 15. The first valve 16 is also operable from the outside, for example by a coupling to the primary inlet port 3 or to the secondary outlet port 6 is made, which acts on an actuator of the first valve 16.

The first valve tappet 15 in FIG. 1 has a first valve element 18 at the side opposite the secondary inlet connection 5.

The first valve member 18 cooperates with a first valve seat 19 disposed in the primary inlet port 3. The primary and the secondary inlet port 3,5 are arranged opposite to the housing 2, so that the first valve stem 15 is mounted axially movable on a straight connecting line between the primary and secondary inlet port 3.5.

The third region 14 in the housing 2 of the heat exchanger 1 has a gap 20 which partially receives the valve stem 15. For sealing the primary side 8 with the primary flow path 7 with respect to the intermediate space 20 and the secondary side 10 with the secondary Flow path 9 with respect to the gap 20, seals 21 are used in each case. The seals 21 simultaneously guide the first valve lifter 15, so that no further bearing on the openings of the boundaries of the areas 12,13,14 are necessary. The intermediate space 20 in the third area 14 has direct access to the surroundings of the housing 2. For this purpose, the intermediate space 20 has an opening 22 which at the same time is an opening in the housing 2.

When fluid flows in the secondary flow path 9, the primary flow path 7 is opened to some degree by the action of the diaphragm 17. If one of the seals 21 leaks during operation, the fluid flows into the intermediate space 20 and evaporates there due to the existing high temperatures in the intermediate space 20 or emerges from the opening 22. This prevents fluid 5 of the primary or secondary side 8, 10 from being mixed with fluid from the secondary or primary side 10, 8, thereby producing, for example, contamination of the one fluid. The gap 20 also prevents that from the primary side 8 to the secondary side 10 or vice versa, a pressure is transmitted in case of failure. The primary side 8 and the secondary side 10 are thus decoupled from one another and do not influence each other in the event of a leak due to spaced boundary walls 23, 24 of the first area 12 and second area 13 with the third area 14 therebetween.

FIG. 2 shows a schematic sectional view of a further heat exchanger 25 with an integrated temperature sensor 26. The temperature sensor 26 extends in the axial direction from the primary flow path 7 in the first region 12 via the gap 20 in the third region 14 in the secondary flow path 9 in the second region 13 o of the heat exchanger 25. The temperature sensor 26 has a bellows 27 which in its axial extent is changeable and a gas closes. The temperature sensor has a sensor chamber 28, which has an expansible medium, which is in thermal communication with a measuring point 29 of the temperature sensor and reacts to temperature changes in the region of the secondary outlet port 6. The measuring point 29 extends into the secondary outlet port 6 and measures there the temperature of the fluid of the secondary side 10th

The sensor space 28 of the temperature sensor 26 is closed and acts on the outer surface of the bellows 27. The interior of the bellows 27 communicates via a fluid path with the gap 20 of the third area 14, which in turn communicates outwardly via the opening 22. With these connections from the interior of the bellows 27 to the surroundings of the housing 2, the temperature sensor 26 is prevented from being influenced by the temperature of the primary flow path 7. Upon heating of the primary flow path 7 in the first region 12, the pressure inside the bellows 27 would increase without further measures.

If the interior of the bellows 27 were closed, expansion-capable material, here a gas, would build up a pressure inside the bellows 27, which would influence the geometry of the bellows 27 and would also act on a second valve 30. This is undesirable and is prevented by the connection with the gap 20 and by the further connection to the environment. The resulting increase in pressure inside the bellows 27 is avoided by the presence of gas in the interior of the

Balgs 27 can expand unhindered. This ensures that the geometry of the bellows 27 is influenced only by the temperature of the expansible material in the sensor chamber 28 and the temperature measurement is precise. On the opposite side of the secondary outlet port 6 in Fig. 2, the primary outlet port 4 is arranged, which has the second valve 30 with a second valve stem 31. The second valve lifter 31 is connected to the temperature sensor 26 at a first axial end and to a return spring 32 at a second axial end. On the second valve plunger 31, a second valve element 33 is arranged in the region of the primary outlet port 4, which cooperates with a second valve seat 34 of the second valve 29. The second valve 29 is in the closed position when a restoring force of the return spring 32 is greater than a counterforce of the temperature sensor 26. In the closed position of the second valve 30, the fluid flow through the primary side 8 of the heat exchanger 25 is interrupted.

With the heat exchanger 25 in Fig. 2, the primary outlet port 4 in dependence on the temperature of the fluid in the secondary outlet port 6 is controllable. By the opposite arrangement of the primary outlet port 4 and secondary outlet port 6 with the second valve 30 at the primary outlet port 4 and the temperature sensor 26 inside the housing 2, a quick reaction in the primary outlet port 4 is possible. The heat exchanger 25 is thereby reliable and reacts almost instantaneously to excessive temperatures of the fluid at the secondary outlet port. 6

3 shows a schematic view of a further heat exchanger 35 with a plurality of heat exchanger plates 36 within the housing 2. The heat exchanger plates 36 are respectively arranged in the first region 12 and in the second region 13, wherein in FIG. 3 the first region 12 is axially to the right of the third Region 14 and the second region 13 is arranged axially to the left of the third region 14. Adjacent primary and secondary flow paths 7, 9 run parallel to one another in the first region 12 and diagonally to one another in the second region 13. In the third area 14 the gap 20 is arranged. There, the primary and secondary flow paths run 7.9 parallel to each other, but approximately at right angles to the primary and secondary flow paths 7.9 in the first and in the second region 12,13. In FIG. 3, the primary and secondary flow paths 7, 9 extend vertically in the first and second regions 12, 13 and horizontally in the third region 14. Heat exchanger plates 36 of the primary side 8, which are flowed through with fluid of the primary side 8, are alternately arranged with heat exchanger plates 36 of the secondary side 10, in which fluid of the secondary side 10 flows. In the first region 12, the primary outlet port 4 and the secondary inlet port 5 are arranged on the housing 2. In the second region 13 of the primary inlet port 3 and the secondary outlet port 6 are arranged on the housing 2. The heat exchanger 35 in Fig. 3 may be formed as previously described in FIGS. 1 and 2. 5

With the arrangement according to FIG. 3, it is also possible to simultaneously integrate the auxiliary control devices of the heat exchanger 1 and of the heat exchanger 25. Here, the first valve 16 is spatially arranged between the primary inlet port 3 and the secondary inlet port 5. At the same time, the temperature sensor 26 is between the secondary

Outlet port 6 and the primary outlet port 4 is arranged, wherein the temperature sensor 26 acts on the second valve 30 at the primary outlet port 4. This is shown in FIG. 4.

FIG. 4 shows a further exemplary embodiment of a heat exchanger 37. The heat exchanger 37 is a combination of the heat exchanger 1 of FIG. 1 and the heat exchanger 25 of FIG. 2 with the arrangement of the heat exchanger plates 36 and the flow paths 7.9 of FIG. 3. The heat exchanger 37 thus has both a temperature control or o regulation as well as a pressure control or regulation. If one

Control or regulation depends on the activation of the first and the second valve 16, 30 from the outside. Preferably, one uses a scheme.

In Fig. 4, the first valve 16 is formed here as a proportional valve. Between the first region 12 and the second region 13, cylinders 38 are arranged which space the first region 12 and the second region 13 from one another. This results in the third region 14 with the intermediate space 20, which is in communication with the environment of the housing 2 outside the heat exchanger 37.

When fluid flows in the secondary flow path 9, due to the force of the flowing fluid on the diaphragm 17 in the first valve 16, the primary flow path 7 is opened to some degree. The heat exchanger 37 reacts almost without inertia to changes in the secondary inlet port 5 while changing the inflow on the primary side 8. If a too high temperature measured at the measuring point 29 of the temperature sensor 26 during operation, the temperature sensor 26 acts by the change of its bellows 27th due to an expansion of an expandable material within the sensor space 28 to the second valve 30. The second valve 30 is throttled in such a case or completely closed. In this way, excessive temperatures are avoided in the removal of the fluid on the secondary side 10.

Claims

claims

A heat exchanger having a housing having a primary inlet port, a primary outlet port, a secondary inlet port and a secondary outlet port, wherein between the primary inlet port and the primary outlet port a primary flow path of a primary side and between the secondary inlet port and the secondary outlet - Laßanschluß a secondary flow path of a secondary side is arranged, wherein the primary flow path with the secondary flow path is in heat-transmitting connection and the heat exchanger comprises at least one control auxiliary device which is arranged in the primary flow path and in the secondary flow path, characterized in that the control auxiliary device a gap (20) is passed, which is arranged between the primary flow path (7) and the secondary flow path (9).

2. Heat exchanger according to claim 1, characterized in that the intermediate space (20) with an environment of the housing (2) is in communication.

3. Heat exchanger according to claim 1 or 2, characterized in that the intermediate space (20) is at least partially limited by the housing (2).

4. Heat exchanger according to one of claims 2 to 3, characterized in that the intermediate space (20) has at least one opening (22), which is arranged in the housing (2).

5. Heat exchanger according to one of claims 2 to 4, characterized in that the control auxiliary device is a first valve tappet (15) of a first valve (16).

6. Heat exchanger according to claim 5, characterized in that the first valve (16) in the region of the secondary inlet port (5) is arranged.

7. Heat exchanger according to one of claims 5 or 6, characterized GE marked 0, that the primary inlet port (3) has a first

Valve seat (19) of the first valve (16).

8. Heat exchanger according to one of claims 5 to 7, characterized in that the first valve (16) has a membrane (17) on 5, which comes into contact with fluid of the secondary flow path (9).

9. Heat exchanger according to one of claims 5 to 8, characterized in that the first valve tappet (15) with the membrane (17) 0 is actuated.

10. Heat exchanger according to one of claims 1 to 9, characterized in that the control auxiliary device is a temperature sensor (26). 5

11. A heat exchanger according to claim 10, characterized in that the temperature sensor (26) communicates with the intermediate space (20) via a fluid path.

12. A heat exchanger according to claim 10 or 11, characterized in that the temperature sensor (26) has a bellows (27), wherein the interior of the bellows (27) is delimited from a sensor space (28) and the interior of the bellows (27) communicates with the space (20).

13. Heat exchanger according to one of claims 10 to 12, characterized in that the temperature sensor (26) with a second valve tappet (31) of a second valve (30) is in communication.

14. Heat exchanger according to claim 13, characterized in that the second valve (30) in the region of the primary outlet port

(4) is arranged.

15. Heat exchanger according to one of claims 13 or 14, characterized in that the second valve (30) has a return spring (32) having a valve element (33) against a second valve seat

(34) presses while the primary outlet port (4) closes.

16. Heat exchanger according to one of claims 1 to 15, characterized in that the heat exchanger (1, 25, 35, 37) has heat exchanger plates (36), wherein in a first region (12) the primary and secondary flow paths (7, 9) are arranged parallel to each other and in a second region (13) the primary and secondary flow paths (7,9) are arranged diagonally to each other.