INTRODUCTION OF CO2 INTO THERMAL WATER

Abstract

A method comprising introducing CO.sub.2 into thermal water (2) in an underground reservoir (3) designated and suitable for the geothermal generation of energy, wherein the CO.sub.2 is discharged from a nozzle (4) and introduced into the thermal water (2) at a discharge flow velocity, wherein the discharge flow velocity is above a lower limit value which is selected in such a way that backflow of the thermal water (2) into the nozzle (4) is prevented, and is below an upper limit value which is selected in such a way that stripping of CO.sub.2 dissolved in the thermal water (2) is prevented.

Claims

1. A method comprising introducing CO.sub.2 into a thermal water (2) in an underground reservoir (3) designated and suitable for a geothermal generation of energy, wherein CO.sub.2 is discharged from a nozzle (4) and introduced into the thermal water (2) in a gaseous state at a discharge flow velocity; wherein the discharge flow velocity is above a lower limit value which is selected in such a way that backflow of the thermal water (2) into the nozzle (4) is prevented, and is below an upper limit value which is selected in such a way that stripping of CO.sub.2 dissolved in the thermal water (2) is prevented.

2. The method according to claim 1, wherein the lower limit value is in the range from 1.5 to 2.5 m/s.

3. The method according to claim 1, wherein the upper limit value is in the range from 9 to 14 m/s.

4. The method according to claim 1, wherein the discharge flow velocity is controlled while taking at least one of the following properties of the thermal water (2) into account: a temperature, a pH, a composition, a flow velocity, a pressure.

5. The method according to claim 1, wherein the discharge flow velocity is controlled while taking at least one of the following properties of the nozzle (4) into account: a geometry, a material, surface characteristics.

6. The method according to claim 1, wherein the discharge flow velocity is controlled using the Langelier index of the thermal water (2) as controlled variable.

7. A method for producing a geothermal generation of energy, comprising: a) conveying thermal water (2) out of an underground reservoir (3) designated and suitable for the geothermal generation of energy, b) passing the thermal water (2) that has been conveyed as per step a) through a heat exchanger (9), c) returning the thermal water (2) that has been passed through the heat exchanger (9) as per step b) into the underground reservoir (3), wherein CO.sub.2 is introduced into the underground reservoir (3).

8. The method according to claim 7, wherein CO.sub.2 is discharged from a nozzle (4) and introduced into the thermal water (2) in the underground reservoir (3) in a gaseous state at a discharge flow velocity, wherein the discharge flow velocity is above a lower limit value which is selected in such a way that backflow of the thermal water (2) into the nozzle (4) is prevented, and is below an upper limit value which is selected in such a way that stripping of CO.sub.2 dissolved in the thermal water (2) is prevented.

9. The method according to claim 8, wherein the lower limit value is in the range from 1.5 to 2.5 m/s.

10. The method according to claim 8, wherein the upper limit value is in the range from 9 to 14 m/s.

11. The method according to claim 8, wherein the discharge flow velocity is controlled while taking at least one of the following properties of the thermal water (2) into account: a temperature, a pH, a composition, a flow velocity, a pressure.

12. The method according to claim 8, wherein the discharge flow velocity is controlled while taking at least one of the following properties of the nozzle (4) into account: a geometry, a material, surface characteristics.

13. The method according to claim 8, wherein the discharge flow velocity is controlled using the Langelier index of the thermal water (2) as controlled variable.

14. An apparatus (1) for introducing CO.sub.2 into thermal water (2) in an underground reservoir (3) designated and suitable for a geothermal generation of energy, comprising: a nozzle (4) for introducing CO.sub.2 into the thermal water (2), and a control device (5), adapted and configured to control a discharge flow velocity at which CO.sub.2 is discharged from the nozzle (4) and introduced into the thermal water (2) in such a way that the discharge flow velocity is above a lower limit value which is selected in such a way that backflow of the thermal water (2) into the nozzle (4) is prevented, and is below an upper limit value which is selected in such a way that stripping of CO.sub.2 dissolved in the thermal water (2) is prevented.

15. The apparatus according to claim 14, wherein the lower limit value is in the range from 1.5 to 2.5 m/s.

16. The apparatus according to claim 14, wherein the upper limit value is in the range from 9 to 14 m/s.

17. The apparatus according to claim 14, wherein the discharge flow velocity is controlled while taking at least one of the following properties of the thermal water (2) into account: a temperature, a pH, a composition, a flow velocity, a pressure.

18. The apparatus according to claim 14, wherein the discharge flow velocity is controlled while taking at least one of the following properties of the nozzle (4) into account: a geometry, a material, surface characteristics.

19. The apparatus according to claim 14, wherein the discharge flow velocity is controlled using the Langelier index of the thermal water (2) as controlled variable.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The figures show particularly preferred exemplary embodiments, however, the invention is not limited to these. It should be pointed out in particular that the figures and especially the scales illustrated are only schematic. In the figures, schematically:

[0066] FIG. 1 shows a visualization of an inventive method comprising the introduction of CO.sub.2 into thermal water in an underground reservoir designated and suitable for the geothermal generation of energy using an inventive apparatus,

[0067] FIG. 2 shows a flowchart of an inventive method for the geothermal generation of energy.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0068] FIG. 1 shows an underground reservoir 3, that is to say one beneath a surface of the earth 11. Thermal water 2 is present in the reservoir 3. The reservoir 3 is designated and suitable for the geothermal generation of energy. It should be noted that FIG. 1 is schematic, especially with respect to the form of the reservoir 3.

[0069] Via a first pipeline 12, the thermal water 2 can be pumped out of the reservoir 3 with a pump 7 and passed to a heat exchanger 9. In the heat exchanger 9 the thermal water 2 can at least partially release its heat, for example to a heat transfer medium. A heat consumer 8 can be supplied with heat using the heat transfer medium that has been heated in the heat exchanger 9, in that the heat transfer medium is circulated through a circuit including the heat exchanger 9 and the heat consumer 8. For instance, a residential building can for example be heated as heat consumer 8. The thermal water 2 can be passed from the heat exchanger 9 back into the reservoir 3 via a second pipeline 13.

[0070] CO.sub.2 can be introduced into the thermal water 2 in the reservoir 3 via a nozzle 4. The nozzle 4 is connected to a CO.sub.2 storage tank 6 via a third pipeline 14. The third pipeline 14 has a CO.sub.2 regulator 10 which may in particular be a valve. The CO.sub.2 flow can be controlled using the CO.sub.2 regulator 10 in such a way that the CO.sub.2 is discharged from the nozzle 4 and introduced into the thermal water 2 at a discharge flow velocity which [0071] is above a lower limit value which is selected in such a way that backflow of the thermal water 2 into the nozzle 4 is prevented, and [0072] is below an upper limit value which is selected in such a way that stripping of CO.sub.2 dissolved in the thermal water 2 is prevented.

[0073] This control can be carried out by means of a control device 5 which is connected at least to the CO.sub.2 regulator 10 and to a sensor unit 15 in the reservoir 3. The connection is preferably implemented digitally. The sensor unit 3 can be used to measure the following properties of the thermal water 2, so that these properties may be taken into account in the control: [0074] a temperature, [0075] a pH, [0076] a composition, [0077] a flow velocity, [0078] a pressure.

[0079] The nozzle 4 and the control device 5 are in particular part of an apparatus 1. In the exemplary embodiment shown, the CO.sub.2 storage tank 6, the pump 7, the heat exchanger 9, the CO.sub.2 regulator 10, the pipelines 11, 12, 13 and the sensor unit 15 are also part of the apparatus 1.

[0080] FIG. 2 shows a flowchart of an inventive method for the geothermal generation of energy. The method can be carried out using what is shown in FIG. 1 and is described using the reference symbols from FIG. 1. The method comprises: [0081] a) conveying thermal water 2 out of an underground reservoir 3 designated and suitable for the geothermal generation of energy, [0082] b) passing the thermal water 2 that has been conveyed as per step a) through a heat exchanger 9, [0083] c) returning the thermal water 2 that has been passed through the heat exchanger 9 as per step b) into the reservoir 3,
wherein CO.sub.2 is introduced into the reservoir 3 by a method according to any of the preceding embodiments.

[0084] Using the described method and the described apparatus 1, thermal water 2 can be used for the geothermal generation of energy, with particularly few undesired deposits arising on the components used for this purpose. In order to compensate for a CO.sub.2 deficit in the thermal water 2, occurring on account of mechanical stresses, CO.sub.2 is introduced into the thermal water 2. This involves controlling a discharge flow velocity at which the CO.sub.2 is discharged from a nozzle 4 and introduced into the thermal water 2.

LIST OF REFERENCE SIGNS

[0085] 1 Apparatus [0086] 2 Thermal water [0087] 3 Reservoir [0088] 4 Nozzle [0089] 5 Control device [0090] 6 CO.sub.2 storage tank [0091] 7 Pump [0092] 8 Heat consumer [0093] 9 Heat exchanger [0094] 10 CO.sub.2 regulator [0095] 11 Surface of the earth [0096] 12 First pipeline [0097] 13 Second pipeline [0098] 14 Third pipeline [0099] 15 Sensor unit

[0100] 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.

[0101] The singular forms a, an and the include plural referents, unless the context clearly dictates otherwise.

[0102] As used herein, about or around or approximately in the text or in a claim means10% of the value stated.

[0103] 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 is defined herein as necessarily encompassing the more limited transitional terms consisting essentially of and consisting of; comprising may therefore be replaced by consisting essentially of or consisting of and remain within the expressly defined scope of comprising.

[0104] 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. Any and all ranges recited herein are inclusive of their endpoints (i.e., x=1 to 4 or x ranges from 1 to 4 includes x=1, x=4, and x=any number in between), irrespective of whether the term inclusively is used.

[0105] Reference herein to one embodiment or an embodiment means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the invention. The appearances of the phrase in one embodiment in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. The same applies to the term implementation.

[0106] As used in this application, the word exemplary is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as exemplary is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word exemplary is intended to present concepts in a concrete fashion.

[0107] Additionally, the term or is intended to mean an inclusive or rather than an exclusive or. That is, unless specified otherwise, or clear from context, X employs A or B is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then X employs A or B is satisfied under any of the foregoing instances. In addition, the articles a and an as used in this application and the appended claims should generally be construed to mean one or more unless specified otherwise or clear from context to be directed to a singular form.

[0108] 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.