EP3791125A1

EP3791125A1 - Condensate extraction device and heat exchanger

Info

Publication number: EP3791125A1
Application number: EP19722794.5A
Authority: EP
Inventors: Austria AG RAG; Ekkehardt Klein; Christoph Nagl; Andreas POLLAK; Werner Muchitsch; Mathias KURRAS; Michael Hernegger; Robert Adler
Original assignee: Linde GmbH
Current assignee: RAG Austria AG; Linde GmbH
Priority date: 2018-05-09
Filing date: 2019-05-02
Publication date: 2021-03-17
Anticipated expiration: 2039-05-02
Also published as: WO2019214849A1; EP3791125B1; EP3791125C0; EP3567329A1; WO2019214849A8

Abstract

The invention relates to a condensate extraction device (38) for a heat exchanger (13), comprising a condensate drain opening (48) and a lock device (40) having a condensate collection chamber (46), wherein the lock device (40) can be arranged in a collection position and in a drain position. The condensate extraction device (38) can be attached to a heat exchanger (13) such that the condensate collection chamber (46) is open to an interior (2a) of the heat exchanger (13) and closed to the condensate drain opening (48) in the collection position and such that the condensate collection chamber (46) is closed to the interior (2a) of the heat exchanger (13) and open to the condensate drain opening (48) in the drain position. The invention further relates to a heat exchanger (13).

Description

description

Condensate extractor and heat exchanger

The invention relates to a condensate extraction device for a heat exchanger, and a heat exchanger. The invention is therefore in particular in the technical field of heat exchangers, preferably for cooling and / or

Liquefaction of natural gas.

Heat exchangers for heating or for cooling a working medium are widely known from the prior art. Without restricting generality, the working medium natural gas will be considered in more detail below. Natural gas off

Soil storage often has a particularly high percentage of unwanted impurities and particularly high water content. It is desirable to remove the impurities as well as the water content from the natural gas before it is used for further purposes. One way to do this is the cooling of the

Natural gas in one or more steps to suitable low temperatures. In particular, in this case, a liquefaction of the natural gas may be appropriate.

During the cooling of natural gas, it comes through the accompanying substances in the

Heat exchangers mostly to deposits on the heat transfer surfaces, the time course of such deposits on the operating conditions and the respective natural gas composition depends. The heat transfer surfaces must therefore be cleaned at certain intervals. For the reasons mentioned, however, it is difficult to specify generally valid cleaning intervals for the relevant heat exchangers.

Condensing and freezing impurities such as water, CO ₂ and

Hydrocarbon compounds separate on the heat transfer surfaces and thus reduce the heat transfer. Even at operating temperatures above the freezing point of water, it may also come to the heat transfer surfaces to form methane hydrate. Cylinder tubes of heat exchangers may for example be provided with a cleaning device, by means of which deposits of the

Heat transfer surfaces can be removed mechanically in the cylinder tubes. For example, DE 10 2015 010 455 A1 discloses such

Cleaning device.

However, such a cleaning device typically has the disadvantage that a condensate collected in a deposition process is present in a reservoir and for extracting the condensate from the reservoir, the condensate must be melted by means of heat supply. However, the heat to be supplied for this purpose causes not only the desired melting of the condensate, but also at least partial evaporation of volatiles in the heat exchanger. In particular, the heat can cause some of the previously in the

Heat exchanger cooled and / or liquefied working medium, such as natural gas, is reheated or even goes back into the gas phase. Thus, the heat input needed to extract the condensate typically results in a

Reduction of the separation efficiency and consequently the efficiency of the

Wärmeabscheiders.

The invention is therefore based on the object to provide a heat exchanger with improved efficiency and / or improved separation efficiency.

This object is achieved by a condensate extraction device and a

Heat exchanger solved with the features of the respective independent claims. Preferred embodiments are the subject of the dependent claims and the following description.

In a first aspect, the invention relates to a condensate extraction device for a heat exchanger. The condensate extraction device has a

Condensate drain on and a lock device with a

Condensate collection chamber, wherein the lock device can be arranged in a collection position and in a drainage position. The condensate extraction device can be attached to a heat exchanger such that the condensate collection chamber is opened in the collection position to an interior of the heat exchanger and to

Condensate drain is closed, and that the condensate collection chamber in the Ablassstellung is closed to the interior of the heat exchanger and is open to Kondensatablassöffnung.

In a further aspect, the invention relates to a heat exchanger with a cylinder tube, wherein on the cylinder tube an inventive

Condensation extraction device is arranged.

The interior of the heat exchanger can be formed in particular by an interior of a cylinder tube of the heat exchanger, through which the

Working medium, such as natural gas, for heating or cooling in the heat exchanger flows.

The invention offers the advantage that by the inventive

Condensate extraction device which can be extracted in a deposition process or during cooling and / or liquefying the working medium condensate, without the need for a heat supply to the previous melting of the condensate is required. In other words, the invention offers the possibility of extracting condensate from the heat exchanger without requiring heating of parts of the heat exchanger and / or of the working medium located therein.

Thus, the invention offers the advantage that heating of cooled in the heat exchanger working fluid and / or a transition to the gas phase can be avoided by already liquefied in the heat exchanger working fluid. Consequently, the invention makes it possible to increase the efficiency of the heat exchanger or of the deposition processes taking place therein.

In addition, the invention has the advantage that it can be dispensed with a provision of heating mechanisms integrated in the heat exchanger, which are conventionally necessary in order to liquefy the condensate. As a result, the structure of the heat exchanger can be simplified and the manufacturing costs and / or the maintenance costs can be reduced.

Preferably, the condensate collection chamber has a condensate extraction opening, which can be arranged facing the interior of the heat exchanger in the collection position and faces the condensate discharge opening in the discharge position. The condensate extraction opening thus offers the possibility, on the one hand, to face the interior of the heat exchanger and to receive the condensate which, for example, passes through the cleaning device from a cleaning device

Condensate extraction opening is conveyed into the condensate collecting chamber, and on the other hand to be facing in the discharge position of the condensate discharge opening to a condensate located in the condensate collection chamber on the

Dump or extract the condensate drain opening.

Preferably, the lock device has a lock capsule, in which the condensate drain opening is formed and which can be connected to the heat exchanger. In this case, the lock device has a lock head element arranged in the lock capsule, in which the condensate collection chamber is formed, and which is pivotable in the lock lock between the collection position and the drainage position. Particularly preferably, the

Lock device be designed in the manner of a ball valve, so that the lock head element in the lock capsule is such pivotable or rotatable, so that the condensate extraction opening in the collection position facing the interior of the cylinder tube of the heat exchanger and by turning or pivoting the lock head element in the lock capsule of Kondensatablassöffnung is zuwendbar and vice versa. In this case, the lock device is preferably designed such that the lock device in the collection position the

Condensate outlet blocked or closes and in the drain position, the interior of the heat exchanger at the connection to the

Condensate extraction device closes. This allows efficient and safe discharge of condensate from the heat exchanger without having to make a direct opening from the interior of the heat exchanger to the condensate drain opening. In particular, this is advantageous in that since

Inside the heat exchanger, a much greater pressure may prevail than the ambient pressure at the condensate drain port. By such

Design of the lock device can these different

Pressure ranges are thus reliably separated from each other and yet the condensate or parts thereof are easily extracted.

Particularly preferably, the lock head element is spherical or cylindrical in shape and is about an axis through the center of the ball or to the cylinder axis pivotable or rotatable. The cylindrical shape or spherical shape of the lock head element does not preclude that the lock head element has the condensate collection chamber or the condensate collection chamber is formed in the lock head element. A therefore touching deviation from the spherical shape or the cylindrical shape is not contrary to the spherical shape or cylindrical shape. Also, the lock head element may have additional elements, which serve for example, the storage and / or the drive or the rotation of the lock head element, which also should not stand in the way of spherical or cylindrical shape. Such a form of the lock head element offers the advantage that a reliable sealing of the lock device can be achieved.

Preferably, the lock device has at least one flushing recess, which extends from an outer side of the lock head element to

Condensate collecting chamber extends and is adapted to direct a flushing fluid into the condensate collection chamber. This offers the possibility of assisting the discharge of condensate from the condensate collection chamber through the condensate discharge opening by the introduction of the flushing fluid in order, for example, to achieve particularly rapid and / or thorough removal of the condensate from the condensate collecting chamber. Furthermore, this offers the advantage that preferably also strong in the

Condensate collecting condensate can be reliably removed.

Preferably, at least one drip edge is formed on the condensate extraction opening. This offers, for example, the advantage that a reliable stripping of transported into the condensate collection condensate is enabled and / or reliable drainage of the condensate when drained by the

Condensate drain opening is made possible.

Preferably, a heat exchanger according to the invention further comprises a

Cleaning device, wherein the heat exchanger is adapted to, by means of the cleaning device located in the cylinder tube condensate over the

Conveying condensate extraction opening in the condensate collection chamber when the lock device is arranged in the collection position, and in the

Drain condensate transported condensate from the condensate collection chamber when the lock device is disposed in the Ablassstellung. This offers the advantage that incurred in the heat exchanger condensate

reliable manner can be transported in the condensate collection chamber.

Preferably, the heat exchanger is designed such that the

Lock head element about an axis perpendicular to a longitudinal direction of the

Cylinder tube between the collection position and the Ablassstellung is pivotable. As a result, the lock device can be sealed particularly reliably and the construction of the heat exchanger can be made particularly simple.

Particularly preferably, the condensate discharge opening is arranged along the longitudinal direction of the cylinder tube.

Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

The invention is schematically illustrated by means of an embodiment in the drawings and will be described below with reference to the drawings.

figure description

Figure 1 shows schematically and in section a longitudinal section through an embodiment of a heat exchanger, divided into Figures 1A and 1 B.

Figures 2A to 2C show cross-sectional views of various preferred embodiments of lock head elements.

Detailed description of the drawings

FIG. 1 is a longitudinal and sectional view (divided into FIGS. 1A (left side) and 1B (right side)) of an embodiment of FIG 1

Heat exchanger 13, as it can be used in particular for cooling natural gas. In this simple embodiment, the heat exchanger 13 a

Outer cylinder tube 1, which surrounds a cylinder tube, which is designed as a cooling coil 2. This cooling coil 2 has at least one, preferably

spiral, channel 23 on its outer surface, which serves to guide a coolant. This channel 23 is generated by a corresponding helix 21 on the outer surface of the cooling coil 2. The inner surface of the hollow cylindrical cooling coil 2 has guide grooves, which serve to guide a cleaning element 12, which is also referred to as a scraper. For example, the cleaning element 12 may be formed as an ice scraper.

The heat exchanger 13 has a cleaning device 10, which has a threaded spindle 3 located in the interior of the cooling coil 2 and extending in an axial direction 100. The threaded spindle 3 is driven by a coupling element 30 and is mounted in a bearing point, which is preferably designed as axial / radial mixing bearing 5. At the other end of the threaded spindle 3, this can be stored in a radial bearing, which is preferably designed as a plain bearing bushing 8.

Further, at the other end of the heat exchanger 13 a

Condensate extraction device 38 is formed, which is connected to the cylinder tube. The condensate extraction device 38 has a lock capsule 42, which encloses the lock head element 44 arranged therein. According to this preferred embodiment, the lock head element 44 is designed spherical, so that the lock device 40 results in an arrangement similar to a ball valve. In the lock head element 44 is the

Condensate collecting chamber 46 is formed, which is formed as a recess and has a size, so that the remaining lock head element 44 has sufficient thickness and stability to the interior 2a of the cylinder tube pressure sealed against the environment or against a formed in the lock capsule 42 condensate drain port 48. In the illustration shown, the lock device 40 is in the collection position, in which a condensate extraction opening 50 of the condensate collection chamber 46 faces the interior 2a of the cylinder tube and connects the condensate collection chamber 46 with the interior 2a. This makes it possible that by means of Cleaning element 12 in the interior 2a accumulated condensate in the

Condensate collection chamber 46 can be transported.

By rotating the threaded spindle 3, the cleaning element 12 is displaced on the threaded spindle 3 along the cooling coil 2 in the axial direction. In the present example, a threaded spindle 3 is used for example with trapezoidal profile. A reversal of the direction of movement of the reamer 12 requires a reversal of the direction of rotation of the threaded spindle 3.

During operation of the heat exchanger 13, for example, moist, contaminated working medium is introduced into the intermediate space between threaded spindle 3 and between cooling coil 2 or into the interior of the cylinder tube via a two-sided working medium inlet opening 14 and flows in the axial direction 100 to the two-sided working medium outlet opening 15 other end of the

Heat exchanger 13. The working fluid flows on the inner surface of the

Hollow-cylindrical cooling coil 2 along the axial direction 100. Coolant is supplied to the space between the cooling coil 2 and the outer cylinder tube 1 via a coolant inlet opening 16 on both sides

Heat exchanger 13 flows and leaves through the coolant outlet opening 17. In this case, the coolant flows spirally in the axial direction in the channel 23 formed between the outer cylindrical tube 1 and the cooling coil 2. The coolant removes heat from the cooling coil 2, which in turn removes heat from the working medium. At this point it should be noted that operating modes are conceivable in which the heat exchanger 13 is flowed through counter to the direction 100. If the

Heat exchanger is operated in countercurrent, inlet and outlet of the coolant are reversed accordingly.

Due to the different pressure ratios between the cooling medium, for example nitrogen at a maximum of 10 bar, and the working medium, here CNG with impurities including nitrogen from 4 to 220 bar, nitrogen as a companion at high pressure (eg. At 10 bar) by liquid nitrogen at low pressure (eg at 1 bar), due to the different pressure-dependent

Phase transitions are brought to liquefying and deposited. The heat exchanger 13 proposed here can thus also be used for the liquefaction of nitrogen. For the purpose of cleaning the heat transfer surfaces, for example of water or ice in the first stage or of higher hydrocarbons, CO2 and / or other impurities, the threaded spindle 3 of a

Drive element via the coupling element 30 is rotated. The

Cleaning element 12, which engages in the thread of the threaded spindle 3 and thereby forms a second contact surface, is thereby displaced in a translational movement in the axial direction. On its way in the axial direction that takes

Cleaning element 12, the said condensed concomitants with. These are then at the other end of the heat exchanger in the

Condensate collection chamber 46 pushed, if the lock device 40 is in collection position.

When the condensate carried into the condensate collection chamber 46 is to be extracted, for example, when the condensate collection chamber 46 is filled with condensate, the lock head element 44 can be pivoted about the axis 102, preferably by 180 °, so that the

Condensate collection chamber 46 and the condensate extraction opening 50 of

Condensate drain opening 48 are facing and the lock device 40 is thus present in the drainage position. In this discharge position and also in any position between the collection position and the discharge position, the lock device 40 at all times seals the interior 2a of the cylinder tube from the condensate discharge opening 48. Between the lock capsule element 42 and the lock head element, at least one sealing element 52 can preferably be arranged in order to further increase the tightness of the lock device 40. In addition, according to the embodiment shown, the lock device 40 further comprises a flushing recess 54, via which a flushing fluid can be introduced into the condensate collection chamber 46 in order to flush out condensate located in the condensate collection chamber 46 reliably. For example, the flushing recess 54 is formed as a channel and / or a bore. Furthermore, the lock head element 46 has a drip edge 56 in order to allow reliable draining or draining of the condensate and / or the rinsing fluid in the release position.

The transfer of the lock device 40 from the collection position in the

Discharge position can be done manually and / or automated. For example, in predetermined time intervals and / or after each cleaning cycle with the

Cleaning element 12 a discharge of the condensate with the lock device 40 done. The draining can preferably be assisted by the use of a flushing fluid which can be introduced through the flushing recess 54.

The temperature of the flushing fluid may be, for example, between 90 K and 400 K, preferably between 233 K and 373 K. According to a particularly advantageous embodiment, the flushing fluid has a higher temperature than the melting point of the condensate. The flushing recess 54 may be configured as a cylindrical bore and preferably have a diameter of at least 2 mm and at most 10 mm, particularly preferably from 3 mm to 6 mm. According to the embodiment shown, the flushing recess 54 is tangential to the

Condensate collection chamber 46 is formed, although others

Embodiments may be advantageous.

It should be noted that the heat exchanger 13 explained here can be adapted and used not only for natural gas liquefaction but also for a large number of industrial applications with appropriate working media. The

Cleaning device 10 and / or the cleaning element 12 and / or the

Condensate extraction device 38 can be adapted as a little complex replacement parts to the needs of the respective applications and quickly replaced in the event of damage.

FIGS. 2A to 2C show cross-sectional views of various preferred embodiments of the lock head elements 44. The lock head element 44 shown in FIG. 2A largely corresponds to the lock head element 44 shown in the heat exchanger of FIG. 1, but differs therefrom in that the lock head element 44 shown in FIG Spülausnehmungen 54, via which flushing fluid can be introduced into the condensate collection chamber 46. According to other preferred embodiments, a different number of flushing recesses 54 may be provided, such as up to ten

Spülausnehmungen 54. The lock head element 44 shown in Figure 2B showed a further preferred embodiment in which a rear wall 46a of the condensate collecting chamber 46 is formed not straight but curved. In particular, the rear wall 46a has a circular segment-shaped curvature, wherein the radius of curvature is greater than the diameter or the width 46b of the condensate collecting chamber 46. Particularly preferably, the radius of curvature of the rear wall 46a is at least twice and at most 20 times as large as the width 46b of the condensate collecting chamber 46. A purging recess 54 is preferably arranged centrally in the rear wall, wherein a plurality of purging recesses 54 may be formed according to other embodiments. Such an arrangement may be advantageous for reliably draining the condensate from the condensate collection chamber 46.

FIG. 2C shows a lock head element 44 according to a further preferred embodiment, which has three flushing recesses 54 which are connected to one another via a distributor arrangement 54a. This allows the easy provision of flushing fluid over several Spülausnehmungen 54, for example, to achieve a uniform flushing of the condensate collection chamber 46, although the flushing fluid must be introduced only via an opening or bore in the manifold assembly 54a. For example, the distributor arrangement 54a may have a centrally arranged bore, via which the flushing fluid can be introduced from outside. The manifold assembly may also have a different number of

Flushing recesses 54 branching therefrom, such as up to ten flushing recesses 54. The branches leading to the flushing recesses 54 may, for example, each enclose an angle of at least 10 ° and at most 135 ° to each other. In the case shown with three Spülausnehmungen 54 close the adjacent Spülausnehmungen 54 preferably at an angle of about 60 ° to each other, that of the arranged around the middle Spülausnehmung (quasi mirrored) Spülausnehmungen 54 is about 120 °. reference numeral

1 outer cylinder tube

2 cooling coil

2a inner wall of the cooling coil

3 threaded spindle

5 axial / radial mixed storage

8 plain bearing bush

10 cleaning device

12 cleaning element

13 heat exchangers

14 working medium inlet opening

15 working medium outlet opening

16 coolant inlet opening

17 Cooling medium opening openings

21 helix on the outer surface of the cooling coil

22 guide groove

23 channel of the cooling coil

30 coupling element

38 condensate extraction device

40 lock device

42 lock capsule

44 lock head element

46 condensate collection chamber

46a Rear wall of the condensate collection chamber 48 Condensate discharge opening

50 condensate extraction opening

52 sealing element

54 flushing recess

54a distribution arrangement

56 drip edge

100 axial direction

102 axis of rotation (of the lock head element)

Claims

claims

A condensate extraction device (38) for a heat exchanger (13), comprising: a condensate discharge port (48);

a lock device (40) with a condensate collection chamber (46), wherein the lock device (40) can be arranged in a collection position and in a release position;

wherein the condensate extraction device (38) is attachable to a heat exchanger (13) such that the condensate collection chamber (46) in the

Collection position to an interior (2 a) of the heat exchanger (13) is opened and closed to the condensate discharge opening (48), and that the

Condensate collecting chamber (46) in the discharge position to the interior (2a) of the heat exchanger (13) is closed and is open to the condensate discharge opening (48).

2. Condensate extraction device (38) according to claim 1, wherein the

Condensate collection chamber (46) has a condensate extraction opening (50), which in the collection position facing the interior (2a) of the heat exchanger (13) can be arranged and in the drainage position of the condensate drain opening (50) faces.

3. Condensate extraction device (38) according to claim 1 or 2, wherein the

Lock device (40) has a lock capsule (42) in which the Kondensatablassöffnung (48) is formed and which is connectable to the heat exchanger (13), and wherein the lock device (40) in the

Has lock capsule (42) arranged Schleusenkopfelement (44), in which the condensate collecting chamber (46) is formed, and which is pivotable in the lock capsule (42) between the collection position and the Ablassstellung.

The condensation extraction apparatus (38) according to claim 3, wherein said

Lock head element (44) is spherical or cylindrical.

5. Condensation extraction device (38) according to one of the preceding claims, wherein the lock device (40) at least one flushing recess (54) extending from an exterior of the lockhead element (44) to the condensate collection chamber (46) and adapted to direct a flushing fluid into the condensate collection chamber (46).

6. Condensation extraction device (38) according to one of the preceding claims, wherein at least one drip edge (56) is formed on the condensate extraction opening (50).

7. heat exchanger (13) with a cylinder tube, wherein on the cylinder tube a

Condensation extraction device (38) according to one of the preceding claims is arranged.

8. Heat exchanger (13) according to claim 7, further comprising a

Cleaning device (10), wherein the heat exchanger (13) is adapted to convey by means of the cleaning device (10) located in the cylinder tube condensate through the condensate extraction port (50) in the condensate collection chamber (46) when the lock device (40) in the collection position is arranged, and in the condensate collection chamber (46) transported

Discharge condensate from the condensate collection chamber (46) when the

Lock device (40) is arranged in the Ablassstellung.

9. The heat exchanger (13) according to claim 7 or 8, wherein the lock head element (44) about an axis (102) perpendicular to a longitudinal direction (100) of the

Cylinder tube between the collection position and the Ablassstellung is pivotable.

10. The heat exchanger (13) according to any one of claims 7 to 9, wherein the

Condensate drain opening (48) along the longitudinal direction (100) of the cylinder tube is arranged.