EP2458315B1 - Regenerative heat exchanger with forced rotor seal - Google Patents

Description

The invention relates to a regenerative heat exchanger according to the type specified in the preamble of claim 1.

Regenerative heat exchangers of the type in question are used to transfer heat from at least one gas volume flow to at least one other gas volume flow. In this case, a rotating heat storage, the so-called rotor, alternately warmed up by at least one gas volume flow and cooled by at least one other gas volume flow again, wherein heat energy is transferred from one to the other gas volume flow. As a result, one of the gas volume flows can be warmed up and another gas volume flow can be cooled. The rotor has two end faces, an outer jacket and, as a rule, a segmentation for receiving the heat storage masses. The rotor is rotatably mounted about a central axis of rotation, wherein this axis of rotation is preferably aligned vertically.

For sealing the guided through the regenerative heat exchanger gas flow rates a sealing system with core, radial and / or circumferential seals is provided. The radial seals are arranged on the front sides of the rotor and are intended to prevent short-circuit volume flows between the gas flow rates. The circumferential seals are arranged on the front edges of the rotor and are intended to prevent leakage volume flows into the rotor housing or into the environment. These seals are arranged stationary with respect to the rotating rotor. Due to a permanent relative movement between the rotor and these seals, as well as a constantly changing thermal expansion of the rotor and associated uneven rotor deformations, high demands are placed on the sealing system in order to achieve low losses (leaks) and thus high efficiency.

Various sealing systems are known from the prior art, which should allow a relatively small sealing gap between the seal and rotor during operation. In this regard, z. B. on the US 3,246,686 , the EP 1 777 478 A1 or on the EP 2 177 855 A1 directed. However, the known sealing systems are often disproportionately expensive and expensive in practice.

An object of the invention is therefore to provide a regenerative heat exchanger of the type in question with a simple and effective sealing system.

This object is achieved by a regenerative heat exchanger with the features of claim 1. Preferred developments and refinements are specified in the dependent claims.

The solution of the above object is achieved by the sealing system for the rotor has at least one fixed relative to the rotor seal, which is pressed on the one hand to the rotor or to a rotor belonging to the component (eg. By acting weights, spring cylinders, actuators and the like) and on the other hand, supported by a plurality of rollers on the rotatable rotor or on a component belonging to the rotor and thus primarily forced out in the axial direction. Ie. the seal in question is subject to a quasi-forced operation, which in operation means that the seal in question with a constant and predetermined by the rollers distance of the thermally induced rotor deformation is continuously updated, whereby a small and constant sealing gap is ensured.

As a result, minimal sealing gaps can be realized with a relatively low structural complexity, whereby short-circuit and / or leakage volume flows are extremely low. With regenerative heat exchangers with extraction, the amount of gas to be extracted is reduced. Likewise, the amount of purge gas is reduced when using purge gas. In addition, the inventive concept proves to be very easy to install and easy to use and maintain. A further advantage is the fact that it is possible to dispense with the electromechanical and usually sensor-controlled adjusting devices for the seals known from the prior art.

It is envisaged that the rollers are arranged in the fixed seal. Furthermore, it is provided that the rollers roll on at least one corresponding running or rolling surface on the rotor or a component belonging to the rotor or are guided between two corresponding and axially spaced-apart rolling surfaces. These rolling surfaces are interchangeable Wear plates formed, which are attached to the rotor (rotor body or a rotor-associated component). Likewise, a reverse arrangement of rollers and treads may be provided.

In order to ensure a minimum sealing gap, in particular in the critical areas in which the seal is pressed onto the rotor, it is preferably provided that the individual rollers at least in the region and in particular only in the range of the control points or pressure points of the seal against the rotor are arranged.

The supported by rollers seal is preferably a radial seal. The supported by rollers seal is in particular a peripheral seal. It is also possible at the same time to support both the radial seals and the peripheral seals at least on one rotor side by means of rollers on the rotating rotor.

According to a particularly preferred embodiment, it is provided that at least one circumferential seal supported by rollers on the rotor is coupled to a radial seal on the same rotor side, such that the relevant radial seal is moved in the axial direction during axial movement of the peripheral seal. For this purpose, the relevant radial seal is arranged to be movable in the axial direction. The coupling between the peripheral seal and the radial seal is effected in particular by a mechanical adjusting mechanism which transmits the axial movements of the peripheral seal by means of at least one adjusting bar or the like to the relevant radial seal. The sealing system on a rotor side can thus perform movements that follow the rotor movements in the axial direction. This preferably radially extending adjusting bar is ideally arranged in the rotor housing of the regenerative heat exchanger and indeed between the respective radial seal and the housing wall, wherein in this area also a sealing collar can be arranged.

• Fig. 1 ein erstes Ausführungsbeispiel eines regenerativen Wärmetauschers;
• Fig. 2 ein Beispiel eines regenerativen Wärmetauschers;
• Fig. 3 ein zweites Ausführungsbeispiel eines regenerativen Wärmetauschers; und
• Fig. 4 ein drittes Ausführungsbeispiel eines regenerativen Wärmetauschers.

The invention will be further described with reference to embodiments shown in the drawings. Shown in schematic sectional partial representations:

• Fig. 1 a first embodiment of a regenerative heat exchanger;
• Fig. 2 an example of a regenerative heat exchanger;
• Fig. 3 a second embodiment of a regenerative heat exchanger; and
• Fig. 4 A third embodiment of a regenerative heat exchanger.

Fig. 1 shows a generally designated 1 regenerative heat exchanger, of which, however, only one half of symmetry is shown. The regenerative heat exchanger 1 comprises a rotor 2, which is rotatably mounted about a vertical axis of rotation A and arranged in a rotor housing 3. The rotor 2 is traversed by a plurality of gas flow rates V, wherein heat is transferred from at least one gas volume flow to at least one other gas volume flow. For sealing the guided through the regenerative heat exchanger 1 gas volume flows V is a sealing system with radial seals 4 and 5 circumferential seals provided. The radial seals 4 are arranged on the end faces of the rotor 2 and are intended to prevent short-circuit volume flows between the gas volume flows V. The circumferential seals 5 are arranged on the front edges of the rotor 2 and are intended to prevent leakage volume flows into the rotor housing 3. The radial seals 4 and the circumferential seals 5 are arranged stationary with respect to the rotating rotor 2. The radial seals 4 and the peripheral seals 5 preferably form, together with any core seals (not shown), a self-contained sealing frame. The arranged on the upper end side and on the lower end face of the rotor 2 seals are formed substantially identical. The following explanations relate, unless otherwise stated, by way of example only to the upper seals and apply analogously to the lower seals.

The upper radial seal 4 is designed as a sealing plate and fastened or suspended in the axial direction by means of a plurality of evenly spaced actuators or spring cylinders 7, 8 and 9 on the rotor housing 3. (The lower radial seal 4 is supported accordingly with spring cylinders or the like.) Each spring cylinder 7, 8 or 9 represents a control point for the radial seal 4. Instead of the spring cylinder 7, 8 and 9 can also be worked with counterweights. The radial seal 4 is formed in the radial direction with joints 41 and 42, which divide the radial seal 4 into several sections. The radial seal 4 can thus adapt to thermally induced rotor deformations. Alternatively, it is possible to perform the radial seal 4 jointless and flexible. Between the radial seal 4 and the upper end face of the rotor 2 there is a sealing gap S with the smallest possible gap. Between the radial seal 4 and the housing wall of the rotor housing 3, a sealing or expansion sleeve (see reference numeral 10 in the lower heat exchanger area) can be arranged, which compensates relative movements of the radial seal 4 relative to the housing wall.

The peripheral seal 5 is designed as an annular sealing frame and fastened or suspended with a plurality of circumferentially uniformly distributed actuators or spring cylinders 11 on the rotor housing 3. The peripheral seal 5 can be segmented, executed with joints or jointless and flexible. In the embodiment shown seals the circumferential seal 5 and the Sealing frame against a radially outwardly projecting from the rotor body rotor flange 6 from. Between the circumferential seal 5 and the rotor flange 6 of the rotor 2 there is likewise a sealing gap with the smallest possible gap. Each spring cylinder 11 represents a control point for the peripheral seal 5, wherein the peripheral seal 5, for example, is pressed against the rotor flange 6 as a result of a weight excess (weight force minus the actuating force in the spring cylinders 11).

In order to ensure a defined sealing gap between the circumferential seal 5 and the rotor flange 6 irrespective of thermally induced rotor deformations, the circumferential seal 5 is supported by means of a plurality of rollers 12 on the rotor flange 6 belonging to the rotor 2. Preferably, a roller 12 is provided at least in the region of each control point. As a result, the circumferential seal 5 maintains a constant distance to the rotor flange 6 during operation and at the same time tracks at least the axial rotor deformations.

In the in Fig. 1 Shown embodiment, the rollers 12 are arranged in a recess in the peripheral seal 5 and preferably also rotatably mounted therein (eg. By means of an axis). When rotating the rotor 2, the rollers 12 roll on a wear plate 14 attached to the rotor flange 6. Preferably, the wear plate 14 is formed segmented in the circumferential direction. Such a wear plate may also be provided on a corresponding rolling surface in the circumferential seal 5. It is also conceivable that the rollers 12 are guided sandwiched between two in the axial direction a spaced apart wear plates. In the design and / or adjustment (adjustment) of the spring cylinder 11 (possibly also the counterweights, if used with such) should generally be taken to ensure that the pressure between the rollers 12 and the corresponding rolling surfaces is kept low. This succeeds z. B. in that the upper spring cylinder 11, the weight load of the circumferential seal 5 substantially absorb or at least reduce.

At the in Fig. 1 shown embodiment, a mechanical coupling of the radial seals 4 with the peripheral seals 5 is provided both on the upper end side and on the lower end side of the rotor 2, to which the peripheral seals 5 and the radial seals 4 are non-positively connected. As a result, the radial seals 4 follow the positively guided movement of the circumferential seals 5 in the axial direction a, for which purpose the radial seals 4 are movably mounted in the axial direction a. As a result, the sealing of the rotor 2 is significantly improved and leaks are significantly reduced.

Fig. 2 shows an example in which, unlike the first embodiment of the Fig. 1 attached to the peripheral seal 5 rollers 12 between two axially spaced Rotor flanges 61 and 62 are guided with corresponding rolling surfaces. As a result, a "direct" positive guidance for the peripheral seal 5 is made possible. Otherwise, the explanations concerning the first exemplary embodiment of FIG Fig. 1 ,

At the in Fig. 3 shown second embodiment, a mechanical coupling of the circumferential seals 5 is also provided with the radial seals 4. For this purpose, the circumferential seals 5 are each connected to a radially extending adjusting bar 16, which brings about a plurality of actuators 17, an adjustment of the respective radial seal 4 (on the same rotor side) in the axial direction a. D. h., The positively driven movement of a peripheral seal 5 is transmitted according to the lever ratios to the relevant radial seal 4 and on the individual sections, including the radial seals 4 movably mounted in the axial direction or z. B. are also flexible. The radially extending adjusting bars 16 are arranged in the interior of the rotor housing 3. Likewise, the adjusting bars 16 could also be arranged outside the rotor housing 3.

Fig. 4 shows a third embodiment in which the radial seals 4 are supported by means of rollers 18 on the end faces of the rotor 2. In this way, the radial seals 4 can be forcibly guided in operation at a constant distance to the end faces of the rotor 2 and the axial rotor deformations are constantly updated. The rollers 18 are arranged in the region of the control points or spring cylinders 7, 8 and 9. At the end faces of the rotor 2 corresponding rolling surfaces are formed. These rolling surfaces may be formed on wear plates 19, as exemplified for the lower, radially inner roller 18.

It should be expressly pointed out that the features of the previously explained in connection with the figures embodiments can be combined with each other, provided that there is no technical contradiction.

Claims (7)

1. A regenerative heat exchanger (1) with a heat storage configured as a rotor (2) which is mounted so as to be rotatable about a central rotational axis (A) and transmits heat of at least one gas volume flow (V) passing through the rotor (2) onto at least one other gas volume flow passing through the rotor (2), and with a sealing system for the rotor (2), the sealing system comprising at least one seal (4, 5) which is fixed in relation to the rotor (2) and is, on the one hand, pressed against the rotor (2) and is, on the other hand, supported on the rotatable rotor (2) by a plurality of rollers (12) which are rotatably mounted by means of axles, the rollers (12) rolling off on at least one corresponding rolling surface on the rotor (2),
   characterized in that
   the rollers (12) are arranged in the seal (4, 5), and
   that at least one of the rolling surfaces, i.e., a rolling surface in the seal or said rolling surface on the rotor (2), is formed on an exchangeable wear plate (14, 19).
2. The regenerative heat exchanger (1) according to claim 1,
   characterized in that
   the individual rollers (12) are arranged at least in the region of actuating points of the seal (4, 5).
3. The regenerative heat exchanger (1) according to any one of the preceding claims,
   characterized in that
   the seal supported by means of rollers (12) is a circumferential seal (5) and/or a radial seal (4).
4. The regenerative heat exchanger (1) according to claim 3,
   characterized in that
   the supported circumferential seal (5) is coupled with a radial seal (4), as a result of which said radial seal (4) is co-moved in axial direction (a) during axial movement of the circumferential seal (5).
5. The regenerative heat exchanger (1) according to claim 4,
   characterized in that
   the coupling between the circumferential seal (5) and the radial seal (4) occurs by a mechanical actuating mechanism which transmits the axial movements of the circumferential seal (5) by means of an actuating bar (16) onto the radial seal (4).
6. The regenerative heat exchanger (1) according to claim 5,
   characterized in that
   the actuating bar (16) is arranged within a rotor housing (3) enclosing the rotor (2).
7. The regenerative heat exchanger (1) according to any one of the preceding claims,
   characterized in that
   at least one sealing collar (10) is arranged between the seal (4, 5) and the rotor housing (3).

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