WO2018086759A1

WO2018086759A1 - Method for changing the temperature of a fluid by means of a tube bundle heat exchanger and tube bundle heat exchanger

Info

Publication number: WO2018086759A1
Application number: PCT/EP2017/025323
Authority: WO
Inventors: Dieter Mihailowitsch; Martin Lang; Alexander Hirsch
Original assignee: Linde Aktiengesellschaft
Priority date: 2016-11-12
Filing date: 2017-11-08
Publication date: 2018-05-17
Also published as: DE102016013459A1

Abstract

The invention relates to a method for changing the temperature of a fluid (b) by means of a tube bundle heat exchanger (100) with multiple tube-side channels (110) and with at least one jacket-side channel (121), in which method a medium (a) is conducted through the tube-side channels (110), wherein a flow (b') of the fluid is introduced into the at least one jacket-side channel (121) through a first inlet opening (131) at a first end of the tube bundle heat exchanger (100) and is led out of the at least one jacket-side channel (121) through an outlet opening (133) at a second end of the tube bundle heat exchanger (100), wherein, for the setting or closed-loop control of a change in temperature of the fluid (b) in accordance with a desired change in temperature, a corresponding partial flow (c) is branched off from the flow (b) of the fluid before the latter is introduced into the at least one jacket-side (121) channel, and said partial flow is introduced into the at least one jacket-side channel (121) via a second inlet opening (132) which is arranged between the first inlet opening (131) and the outlet opening (133), and to a tube bundle heat exchanger (100) of said type.

Description

description

Process for temperature change of a fluid by means of a shell-and-tube heat exchanger and shell-and-tube heat exchanger

The invention relates to a method for operating a shell and tube heat exchanger and a tube bundle heat exchanger according to the preambles of the independent claims.

PRIOR ART For various applications, it is necessary to cool or heat fluids. For example, in gas generators, very high temperatures often occur in the gases, which are too high for further use. Also, at such high temperatures of gases corrosion problems can occur in pipelines. Likewise, in various applications, a cooling of gases or gas mixtures may be necessary to reduce subsequent compression work.

A common technique for cooling or heating fluids is the use of heat exchangers, especially so-called tube bundle heat exchangers.

Tube bundle heat exchangers generally have a plurality of tubes, usually of very small diameter, which are enclosed by a jacket in which a channel is formed for the passage of fluids. One possibility is now, one

Cooling medium or a heating medium through the tubes (ie in the tube-side channels) to lead and to lead to be cooled or to be heated fluid through the shell-side channel. It is also conceivable that the reverse case, as shown for example in GB 848 099 A, there for cooling of fuel. In this way, an indirect heat transfer between the cooling medium or heating medium and the fluid take place.

Often it may also be necessary in such a cooling or heating to adjust or regulate the cooling or heating itself, for example, if a cooling or heating of the fluid to a certain temperature is desired. For this purpose, various ways are known. For example, it is described in DE 10 2008 048 405 B3 that the

Cooling medium, which is guided there through the shell-side channel can be partially bypassed by using an external bypass on the shell-side channel, so as to change the cooling of a fluid, which is passed there through the tube-side channels.

From EP 0 356 648 A1 and EP 2 312 252 A1, for example

Known heat exchangers in which the fluid to be cooled is passed through the tube-side channels, but with an internal bypass is provided, through which a part of the fluid to be cooled can be passed, so as to the cooling

adjust.

From DE 17 76 089 A, for example, a water cooler for gaseous media is known, in which the fluid to be cooled (or medium) is guided through the shell-side channel. To adjust the cooling, a part of the to be cooled

Medium already removed earlier than the remaining part of the shell-side channel and then combined with this.

In the mentioned possibilities for cooling or heating of fluids, however, there is the risk of undesirable condensation or evaporation, especially in certain load ranges, as for example in the

Cooling of synthesis gas with simultaneous heating of water for a water heater is the case in which the water is used on the one hand as a cooling medium, but on the other hand it is heated simultaneously for the desired application.

The present invention sets itself the task against this background, a

Possibility to provide a temperature of a fluid without unwanted

Condensation or without changing unwanted evaporation of the medium, especially in extreme load ranges.

Disclosure of the invention

This object is achieved by a method for changing the temperature of a fluid by means of a tube bundle heat exchanger and a tube bundle heat exchanger with the Characteristics of the independent claims solved. Embodiments are

Subject matter of the dependent claims and the following description.

Advantages of the invention

The present invention is based on a method known per se

Temperature change, ie in particular for cooling or for heating, of a fluid by means of a tube bundle heat exchanger. As already mentioned, such a shell-and-tube heat exchanger has a plurality of tube-side channels and at least one jacket-side channel. In this case, a medium (in the case of cooling also referred to as cooling medium) is now guided through the tube-side channels.

A stream of fluid is then introduced into the at least one shell-side channel through a first entry port at a first end of the shell-and-tube heat exchanger and through an exit port at a second end of the shell

Tube bundle heat exchanger again led out of the at least one shell-side channel. In this way, the fluid whose temperature is to be changed and which may be, in particular, a gas or a gas mixture, in particular synthesis gas, cooled by indirect heat transfer to the medium, which may be in particular water or heated. In the case of cooling of the fluid can be used as a first end, a hot end and a second end of a cold end of the tube bundle heat exchanger. Accordingly, when the fluid is heated, a cold end may be used as the first end, and a hot end of the shell-and-tube heat exchanger may be used as the second end. Under a cold end is the end of the

Shell and tube heat exchanger to understand the (still cold) medium

is introduced. Accordingly, the warm end is that end at which the now heated medium is led out again.

It is also useful in such a shell and tube heat exchanger, when it is operated with countercurrent flow, i. that the fluid in the shell-side channel in the opposite flow direction to the medium in the rohrseitgen channels is passed through the tube bundle heat exchanger, since in this way the

Temperature conditions in the tube bundle heat exchanger can be used optimally. As a further possibility for adjusting or regulating the temperature change, ie in particular the cooling or the heating, is now - in addition to the possibilities already mentioned above - still in consideration to change the tube-side channels, so that the way for the medium longer or shorter or to lead the medium through more or less tubes. Although you can

Condensation or evaporation can be avoided, but the realization of such a tube bundle heat exchanger due to the required switchable pipes or pipe groups is very complex.

According to the invention is now to adjust or control a temperature change, ie in particular a cooling or heating, of the fluid according to a desired temperature change (ie, for example, with regard to a desired temperature of the fluid or a desired cooling capacity of

Tube bundle heat exchanger) diverted from the flow of fluid before introduction into the at least one shell-side channel, a corresponding partial flow and introduced via a second inlet opening, which is arranged between the first inlet opening and the outlet opening, in the at least one manteilseitigen channel.

In this way, therefore, two partial streams (that is, the partial stream branched off from the stream and the remaining stream remaining) are formed, which are introduced at different locations into the at least one shell-side channel and then reunited there after the diverted partial stream has been introduced. At the point at which the partial flow is introduced into the at least one shell-side channel, however, the residual flow has already been cooled or heated and is therefore colder or warmer than the later-introduced partial flow. By the approximation of

Temperatures of both partial flows in the then reunited stream thus sets an overall higher or lower temperature than if the entire flow through the first inlet opening would be appropriate.

The desired temperature change can be achieved by a suitable division of the original flow in the two partial streams, since then

Different amounts of fluid are cooled or heated to different degrees. Likewise, the position of the second inlet opening has an influence on the Temperature change. The later the diverted partial flow is supplied to the residual flow or combined with it, the less strongly the fluid is cooled or heated. While the temperature change can be adjusted or regulated via the distribution of the current to the partial flows in an existing shell-and-tube heat exchanger, the arrangement of the second inlet opening can also take into account the other parameters such as the number of tube-side channels, their diameter and length, and the exact Course, the cross-section and the length of the shell-side channel - a design of the shell and tube heat exchanger to desired limits of the change in temperature.

Compared to the mentioned option with switchable pipes or pipe groups, a significantly lower outlay is necessary here, since only a second inlet opening in the jacket side channel, which in any case can be easily reached from the outside, must be provided. Likewise, in the proposed possibility especially in extreme load ranges, such as 1 to 10, condensation or

Evaporation avoided since an unification of the two partial flows takes place early, before a difference in the temperatures is too high, as would be the case with a complete bypass. Preferably, the partial flow is diverted to the flow using at least one adjustable and / or controllable valve, in particular continuously adjustable, valve. Such a valve may, for example, be provided at a corresponding point in a supply line of the fluid. It is conceivable also an arrangement very close to the jacket or directly on the shell of the tube bundle heat exchanger, so that a line to the second inlet opening can be performed directly on the jacket along.

In a tube bundle heat exchanger according to the invention for changing the temperature, that is to say in particular for cooling or heating a fluid, a plurality of tube-side channels and at least one jacket-side channel are accordingly provided, wherein a medium can be guided through the tube-side channels. In addition to a first inlet opening at a first end of the shell-and-tube heat exchanger, through which a stream of the fluid can be introduced into the at least one shell-side channel, and an outlet opening at a second end of the shell-and-tube heat exchanger through which the fluid can be led out of the at least one shell-side channel, In this case, there is a second inlet opening which is arranged between the first inlet opening and the outlet opening and through which a partial stream branched off from the flow of the fluid before introduction into the at least one jacket-side channel can be introduced into the at least one partial-side channel. In the case of cooling of the fluid in the shell-side channel may be provided as a first end of a hot end and a second end of a cold end of the tube bundle heat exchanger. Accordingly, in a heating of the fluid in the

shell side channel as the first end of a cold end and be provided as a second end of a hot end of the tube bundle heat exchanger.

For setting or regulation of the branched partial flow and thus the

Temperature change of the fluid can be provided a corresponding valve, as has already been explained in more detail. Such a setting or in particular the control can also be automated.

The invention will be explained in more detail with reference to the accompanying drawing showing various parts of the system, by means of which the

inventive measures are explained. Short description of the drawing

Figure 1 shows a tube bundle heat exchanger according to an embodiment of the invention in a schematic representation. Detailed description of the drawing

1, a shell-and-tube heat exchanger 100 is schematically illustrated in a sectional view that may be used to change the temperature of a fluid (shown as cooling the fluid in this example) that may be supplied to the shell and tube heat exchanger 100. The basic principle of the shell-and-tube heat exchanger 100 corresponds to a conventional shell-and-tube heat exchanger, as is also partially described in the documents cited above.

The tube bundle heat exchanger 100 in this case has a plurality of tubes or tube-side channels 1 10, through which a medium, here as a cooling medium, such as, for example, water out becomes. For this purpose, the medium is supplied as stream a of an inlet chamber 1 1 1 and from there out through the tube-side channels 1 10 in an outlet chamber 1 12th About the outlet chamber 1 12, the medium then back out of the

Tube bundle heat exchanger 100 led out.

The tube-side channels 1 10 are surrounded by a jacket 120. In the coat

120, a shell-side channel 121 is formed, through which the, here cooled, fluid can be performed. For this purpose, partition walls 122 are provided in the present case, through which the shell-side channel 121 is formed in the manner of a labyrinth.

The fluid, such as, for example, a synthesis gas, is introduced into the jacket-side channel through a first inlet opening 131, which can be formed, for example, in the form of an inlet nozzle

121 introduced. The fluid can then flow through the mantelsetigen channel 121 and exit through an outlet opening 133, which may be formed, for example. In the form of an outlet nozzle, again from the shell-side channel 121.

The first inlet opening 131 is provided at a first, here a warm, end of the tube bundle heat exchanger 100, ie at one end, at which the medium has already flowed through the tube-side channels 1 10 and is therefore warmed up. The outlet opening 133 is accordingly provided at a second, here a cold, end of the shell-and-tube heat exchanger 100, at which the medium just enters the tube-side channels 110 and is therefore still cold.

According to the invention, a second inlet opening 132 is now provided, which is arranged between the first inlet opening 131 and the outlet opening 133 and through which fluid, which is also to be cooled, can be introduced into the shell-side channel 121. The second inlet opening 132 may, as well as the first

Inlet opening 131, for example, be designed as inlet connection. Fluid, which is introduced through the second inlet opening 132 into the shell-side channel 121, thus mixes with fluid that has been introduced through the first inlet opening 131, has already traveled a certain distance in the shell-side channel 121 and therefore already to a certain extent Degree was cooled. In the case shown, a valve 140 is used, by means of which a partial stream c can be branched off from the original stream b of the fluid, which is introduced through the second inlet opening 132 into the shell-side channel 121. By contrast, the residual flow b 'remaining from the original stream b is introduced into the shell-side channel 121 through the first inlet opening 131.

Depending on the ratio of the two streams b 'and c with regard to their volume flow, the result is therefore a different strength than the original stream b

Temperature change, here cooling, of the fluid as it exits the tube bundle heat exchanger 100 through the outlet opening 133.

For this purpose, the valve 140 can be continuously adjustable and, in particular, also adjustable. For adjustment or regulation can, for example, a suitable tax or

Arithmetic unit 141 may be provided, by means of which the valve can be adjusted or adjusted according to, for example, a predetermined temperature change, here cooling, or a temperature to be reached.

As an alternative to the three-way valve shown here, appropriately connected control valves for the respective partial flows c and / or b 'may also be used.

With the tube bundle heat exchanger 100 shown, it is thus possible within certain limits, which are predetermined inter alia by the length of the shell-side channel as well as the positioning of the second inlet opening with respect to the first inlet opening and the outlet opening, a temperature change, here a cooling, arbitrarily set and in particular also to regulate. However, no unwanted condensations or evaporations occur.

For a heating instead of a cooling of the fluid, for example, a correspondingly higher starting temperature of the medium, which is higher than that of the fluid, can be used.

Claims

claims

1 . Process for changing the temperature of a fluid (b) by means of a

A tube bundle heat exchanger (100) having a plurality of tube-side channels (1 10) and at least one shell-side channel (121), in which a medium (a) through the tube-side channels (1 10) is guided, wherein a stream (b ') of the fluid through a first inlet opening (131) at a first end of the shell and tube heat exchanger (100) in the at least one shell-side channel (121) and introduced through an outlet opening (133) at a second end of the

Tube bundle heat exchanger (100) is led out of the at least one shell-side channel (121),

characterized in that for setting or regulation of a

Temperature change of the fluid (b) corresponding to a desired

Temperature change of the stream (b) of the fluid prior to introduction into the at least one shell-side (121) channel branched off a corresponding partial flow (c) and via a second inlet opening (132) between the first

Inlet opening (131) and the outlet opening (133) is arranged, is introduced into the at least one shell-side channel (121).

2. The method of claim 1, wherein the partial stream (c) is branched off from the stream (b) using at least one adjustable and / or controllable valve (140).

3. The method of claim 2, wherein as the at least one valve (140) a

continuously adjustable valve is used.

4. The method according to any one of the preceding claims, wherein as fluid (b) a

Synthesis gas and / or as a medium (a) water is used.

5. The method according to any one of the preceding claims, wherein as

Tube bundle heat exchanger (100) a tube bundle heat exchanger with

Countercurrent flow is used.

6. The method according to any one of the preceding claims, for cooling the fluid (b), wherein as a first end of the tube bundle heat exchanger (100) has a warm end and a cold end is used as the second end of the shell and tube heat exchanger (100).

7. The method according to any one of claims 1 to 5, for heating the fluid (b), wherein the first end of the tube bundle heat exchanger (100) is a cold end and the second end of the tube bundle heat exchanger (100) is a hot end is used.

8. tube bundle heat exchanger (100) for changing the temperature of a fluid (b) having a plurality of tube-side channels (1 10) and at least one shell-side channel (121), in which a medium (a) through the tube-side channels (1 10) is feasible, with a first inlet (131) at a first end of the

A tube bundle heat exchanger (100) through which a stream (b) of the fluid in the at least one shell-side channel (121) can be introduced, with a

Outlet opening (133) at a second end of the tube bundle heat exchanger (100) through which the fluid from the at least one shell-side channel (121) can be brought out,

characterized by a second inlet opening (132) which is arranged between the first inlet opening (131) and the outlet opening (133) and through which a partial stream branched off from the stream (b) of the fluid before introduction into the at least one shell-side channel (121) (C) in the at least one manteilseitigen channel (121) can be introduced.

9. tube bundle heat exchanger (100) according to claim 8, which is further configured with at least one adjustable and / or controllable valve (140), by means of which the partial flow (c) of the stream (b) is branched off.

10. The tube bundle heat exchanger (100) according to claim 9, which is adapted to set or regulate a change in temperature of the fluid (b) according to a desired temperature change and using the at least one valve (140) the partial flow (c) according to the current ( b) branch off the fluid.

1 1. A tube bundle heat exchanger (100) according to claim 9 or 10, wherein the at least one valve (140) is formed as a continuously adjustable valve.

12. tube bundle heat exchanger (100) according to any one of claims 8 to 1 1, which is adapted to use a synthesis gas as a fluid (b) and / or water as the medium (a).

13. tube bundle heat exchanger (100) according to any one of the preceding claims, which is designed as a tube bundle heat exchanger with countercurrent flow.

14. tube bundle heat exchanger (100) according to any one of claims 8 to 13, for

Cooling the fluid, wherein the first end comprises a warm end and the second end comprises a cold end.

15. tube bundle heat exchanger (100) according to any one of claims 8 to 13, to

Heating the fluid, wherein the first end comprises a cold end and the second end comprises a warm end.