STEAM GENERATION SYSTEM

Abstract

Steam generating system comprising a steam generator and a steam drum, wherein the downpipe, coming from the steam drum, passes through the water jacket of the steam generator above the heating tube or tubes of the steam generator and extends therein as far as the water jacket volume region which is situated below the heating tube or tubes.

Claims

1-9. (canceled)

10. A steam generating system comprising: a steam generator having a water jacket and at least one heating tube extending therein for the passage of a heat transfer medium; a steam drum; at least one riser pipe configured to connect the water jacket of the steam generator hydraulically to the steam drum to enable the steam to be passed into the steam drum; and at least one downpipe configured to connect the steam drum hydraulically to the water jacket of the steam generator to enable the water to be returned from the steam drum to the water jacket of the steam generator, wherein the downpipe, coming from the steam drum, passes in its upper half through the water jacket of the steam generator and extends therein as far as its lower half.

11. The steam generating system according to claim 10, wherein the steam generator and the steam drum are arranged in such a way relative to one another, and the riser pipe and downpipe are designed in such a way that the water to be evaporated can be moved between the water jacket of the steam generator and the steam drum by natural circulation.

12. The steam generating system according to claim 10, wherein at least one pump is installed to assist the water circulation between the steam generator and the steam drum.

13. The steam generating system according to claim 10, wherein the steam generator and the steam drum are designed as horizontally arranged, cylindrical pressure vessels.

14. The steam generating system according to claim 13, wherein the riser pipes and the downpipes enter the water jacket of the steam generator in the 0 o'clock position and enter the steam drum jacket in the 6 o'clock position.

15. The steam generating system according to claim 10, wherein the steam generator is designed as a shell-and-tube evaporator.

16. The steam generating system according to claim 15, wherein the downpipe is passed around the tube bundle within the water jacket of the steam generator.

17. The steam generating system according to claim 15, wherein the downpipe is passed through the tube bundle within the water jacket of the steam generator.

18. A method of using a steam generating system that is arranged downstream of a steam reforming reactor, the method comprising the steps of: providing the steam generating system as claimed in claim 10; and using the synthesis gas emerging from the steam reforming reactor as a heat transfer medium in the steam generator of the steam generating system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Further features, advantages and possible uses of the invention will also become apparent from the following description of illustrative embodiments and the drawings. In this case, all the features described and/or depicted in themselves or in any combination form the subject matter of the invention, irrespective of the way in which they are grouped in the claims or the dependency references thereof.

[0035] In the drawings:

[0036] FIG. 1 shows a longitudinal section through a steam generating system according to the invention,

[0037] FIG. 2 shows a cross section through a steam generating system according to the prior art,

[0038] FIG. 3a shows a first cross section through a steam generating system according to the invention,

[0039] FIG. 3b shows a second cross section through a steam generating system according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0040] FIG. 1 illustrates the steam generating system 1, comprising the steam generator 2 and the steam drum 3 as principal components. The steam generator 2 is designed as a shell-and-tube evaporator and is set up horizontally. The hot synthesis gas 4 coming from a steam reforming reactor (not depicted) is introduced into the inlet chamber 5 of the steam generator 2, is distributed there between the tubes 6 of the tube bundle 13, flows onward into the outlet chamber 7 and leaves the steam generator 2 for further treatment or use (not shown).

[0041] The steam drum 3 is arranged above the steam generator 2. The boiler feedwater 8 to be evaporated is fed into said steam drum. The water to be evaporated is circulated via the riser pipes 9 and the downpipes 10 in a natural circulation. The steam/water mixture entering the steam drum 3 via the riser pipes 9 is separated there, the steam 11 is discharged for further use and the water is fed back into the steam generator via the downpipes 10. Here, the downpipes enter the jacket 12 of the steam generator 2 in the 0 o'clock position and then run past the heating tubes of the tube bundle 6 within the jacket 12 as far as the lower volume region of the jacket 12. The downpipes end as low as possible in the jacket to avoid steam bubbles getting into the downpipe and to achieve as large as possible a static head, i.e. as large as possible a vertical distance between the lower and the upper end of the downpipe, thereby assisting natural circulation.

[0042] FIG. 2 shows a cross section through a steam generating system with the downpipes 10 routed in accordance with the prior art. To increase clarity, the riser pipes have not been depicted, but, as in the example shown in FIG. 1, they are once again arranged in the 0 o'clock position of the jacket 12. The downpipes 10 are connected to the steam drum 3 in the 4 and in the 8 o'clock position, run externally around the steam generator 2 and likewise open in the steam generator jacket 12 in the 4 and the 8 o'clock position.

[0043] FIG. 3a shows a cross section through a steam generating system 1 with the downpipe 10 routed in accordance with the invention. The downpipe 10 is connected to the steam drum 3 in the 6 o'clock position and passes through the jacket 12 of the steam generator 2 in the 0 o'clock position. Within the jacket 12, the downpipe 10 runs around the tube bundle 13 as far as the volume region of the water jacket 12 situated thereunder.

[0044] FIG. 3b likewise shows a cross section through a steam generating system with the downpipe 10 routed in accordance with the invention. The downpipe 10 is likewise connected to the steam drum 3 in the 6 o'clock position and passes through the jacket 12 of the steam generator 2 in the 0 o'clock position. Within the jacket 12, the downpipe 10 passes through the tube bundle 13 to the volume region of the water jacket 12 situated thereunder.

INDUSTRIAL APPLICABILITY

[0045] The invention offers the possibility of embodying a steam generating system in a less expensive and more space-saving way, wherein the setup of the system can also be carried out more flexibly in relation to the upstream and downstream apparatus.

[0046] While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims. The present invention may suitably comprise, consist or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. Furthermore, if there is language referring to order, such as first and second, it should be understood in an exemplary sense and not in a limiting sense. For example, it can be recognized by those skilled in the art that certain steps can be combined into a single step.

[0047] The singular forms a, an and the include plural referents, unless the context clearly dictates otherwise.

[0048] Comprising in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing (i.e., anything else may be additionally included and remain within the scope of comprising). Comprising as used herein may be replaced by the more limited transitional terms consisting essentially of and consisting of unless otherwise indicated herein.

[0049] Providing in a claim is defined to mean furnishing, supplying, making available, or preparing something. The step may be performed by any actor in the absence of express language in the claim to the contrary.

[0050] Optional or optionally means that the subsequently described event or circumstances may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.

[0051] Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range.

[0052] All references identified herein are each hereby incorporated by reference into this application in their entireties, as well as for the specific information for which each is cited.

LIST OF REFERENCE SIGNS

[0053] 1 steam generating system according to the invention

[0054] 1 steam generating system according to the prior art

[0055] 2 steam generator

[0056] 3 steam drum

[0057] 4 synthesis gas

[0058] 5 inlet chamber

[0059] 6 heating tube

[0060] 7 outlet chamber

[0061] 8 boiler feedwater

[0062] 9 riser pipe

[0063] 10 downpipe

[0064] 10 downpipe according to the prior art

[0065] 11 steam

[0066] 12 jacket of the steam generator

[0067] 13 heating tube bundle