Method and device for generating steam and use

Abstract

The application relates to a method and to a device for generating steam. Water (1) is fed into a structure (2) comprising at least one channel (3) for the flow of water and formed of metal. The structure is heated by means of an electrical element (4), and the water is vaporized in the channel within the structure. Steam pressure is measured in the channel or after the channel and the feed of water is controlled based on the pressure measurement and predetermined pressure limit values, and steam (5) is conducted out from the structure. Additionally, the application relates to the use of the method.

Description

[0001] METHOD AND DEVICE FOR GENERATING STEAM AND USE

[0002] FIELD

[0003] The application relates to a method defined in claim 1 and to a device defined in claim 8 for generating steam . Additionally, the application relates to the use of the method as defined in claim 15 .

[0004] BACKGROUND

[0005] Various methods and devices for generating steam are known in the prior art . Steam is typically needed in many industrial processes or steam networks . Steam may be generated for example in a boiler as a separate process or in connection with another industrial process .

[0006] PURPOSE

[0007] The purpose of the invention is to provide a new method and device for generating steam . Additionally, the purpose of the invention is to generate steam efficiently and in an environmentally friendly way . Additionally, the purpose of the invention is to easily generate steam also for small-scale purposes . Additionally, the purpose of the invention is to provide a useful method and device for harmoni zing operations between di f ferent energy networks , e . g . for balancing operations of a steam network and an electrical network .

[0008] SUMMARY

[0009] The method, device and use according to the invention are characteri zed by what has been presented in the claims .

[0010] In a method for generating steam, water is fed into a structure comprising at least one channel for the flow of water, the structure is heated by means of a heating device , the water is vaporized in the channel within the structure, and steam is conducted out from the structure .

[0011] A device for generating steam comprises at least one structure, at least one inlet in the structure for feeding water into the structure and at least one channel arranged inside the structure for providing a flow of water, and at least one heating device for heating the structure and vaporizing the water in the channel , and at least one outlet for conducting steam out from the structure .

[0012] The method may be used in connection with a steam network, for harmoni zing operations of two or more energy networks , for balancing operations of a steam network and an electrical network, in industrial processes requiring steam, in steam generation plants or corresponding applications , or in combinations thereof .

[0013] DETAILED DESCRIPTION

[0014] In a method for generating steam, water is fed into a structure comprising at least one channel for the flow of water and formed of metal , the structure is heated by means of an electrical element , the water is vapori zed in the channel within the structure , the steam pressure is measured in the channel or after the channel , preferably immediately after the channel , and the feed of water is controlled based on the pressure measurement and predetermined pressure limit values , and steam is conducted out from the structure . Preferably, the steam may be fed into a steam network or into a process requiring steam.

[0015] A device for generating steam comprises at least one structure formed of metal , at least one inlet in the structure for feeding water into the structure and at least one channel arranged ins ide the structure for providing a flow of water, and at least one electrical element for heating the structure and vapori zing the water in the channel , at least one measurement device for measuring steam pressure in the channel or after the channel and at least one control device for controlling the feed of water based on the pressure measurement and predetermined pressure limit values , and at least one outlet for conducting steam out from the structure .

[0016] In this context , a structure re fers to any structure , container, reactor or corresponding structure that comprises at least one channel arranged inside the structure and that is three-dimensional . The structure may be any shape , e . g . cylindrical , plate-shaped, cubic, prismatic, or other suitable shape . The structure may be formed o f any metal material . In one embodiment the structure is formed of steel . In one embodiment the structure is a sealed structure , i . e . an enclosed structure , in which preferably the metal trans fers heat . In one embodiment the structure is a thick pipe or a thick metal plate . In one embodiment the structure is a sealed structure inside which a channel has been arranged, e . g . by machining, drilling or boring . In one embodiment the channel has been machined directly inside the structure , pre ferably through the structure , and the walls of the channel are formed of the material of the structure . In one embodiment the wall s o f the channel are coated . In one embodiment a channel-shaped opening or passage has been machined inside the structure, with a pipe forming the channel arranged inside the structure . In one embodiment the structure is not fully sealed, but wherein preferably the metal trans fers heat from the electrical element to the channel .

[0017] In one embodiment the structure comprises more than one channel for the flow of water . In one embodiment several channels have been arranged inside the structure in flow communication with each other to form a system of channels for providing a flow of water in the structure . In one embodiment the flow of water is arranged in the structure according to a predefined flow design .

[0018] In this context , a channel refers to any channel , pipe or the like in which water may flow and vapori ze . In one embodiment the channel is one continuous channel . In one embodiment the channel is formed of more than one channel segment .

[0019] In one embodiment the steam pressure is controlled in the structure by controlling the water level in the channel . Preferably, i f the pressure drops , the feed of water will be increased, or i f the pressure rises , the feed of water will be decreased or the feed will be paused .

[0020] The control device used may be any control device suitable for the purpose . In one embodiment the feed of water is controlled by means of a controllable valve . In one embodiment the device comprises at least one controllable valve for controlling the feed of water . In one embodiment the control device comprises a controllable valve . Any controllable valve suitable for the purpose may be used in the method and the device .

[0021] The pressure limit values may be determined as being suitable values for the application . In one embodiment the pressure limit values are determined as being a value or values within the range of 2 - 120 bar, and in one embodiment 3 - 120 bar . In one embodiment the pressure limit value is 3 - 16 bar . In one embodiment the pressure limit value is 4 - 10 bar .

[0022] The measurement device used may be any measurement device suitable for the purpose . In one embodiment the measurement device is a pressure measurement device .

[0023] In one embodiment the electrical element is arranged outside the structure . In one embodiment the electrical element is arranged outside the structure , and is arranged to heat the structure . Preferably, the heat transfer is provided by means of the material of the structure to the water within the channel . The electrical element used may be any electrical element which is suitable for the purpose and by means of which a structure, e . g . an electrical resistor or other electrically driven heating device, may be heated . In one embodiment the electrical element is an electrical resistor . In one embodiment the electricity of the electrical element is generated by renewable energy, e . g . by the sun or the wind . In one embodiment the electricity of the electrical element is generated by solar panels . In one embodiment the electricity of the electrical element is generated by wind power .

[0024] In one embodiment the temperature in the structure is 150 - 900 °C, and in one embodiment 200 - 900 ° C . In one embodiment the temperature in the structure is 200 - 600 °C . In one embodiment the temperature in the structure is arranged to be within the range of 300 - 600 °C, in one embodiment 350 - 550 ° C .

[0025] In one embodiment the device comprises at least one frequency converter, e . g . for controlling the frequency and voltage . In one embodiment the device comprises at least one frequency converter when the method and / or the device are used for balancing operations of a steam network and an electrical network .

[0026] In one embodiment the device comprises more than one structure and more than one electrical element, and the electrical elements are arranged between the structures . The structures may be arranged in parallel or in series to vaporize the water . In one embodiment the structures are arranged in parallel . In one embodiment the structures are arranged is series . The electrical elements may be arranged to heat one or two structures . In one embodiment an electrical element located between the structures is arranged to heat two structures simultaneously .

[0027] In one embodiment the generated steam is fed to a steam network . The steam may be fed to the steam network by suitable means , e . g . by a pipe , a steam pipe or the like . In one embodiment the pressure in the steam network is within the range of 3 - 8 bar, in one embodiment 4 - 6 bar .

[0028] The method and the device according to the invention may be used in any appl ication . The method and the device may be easily modi f ied according to the intended use or application . The method and the device may be used for example in connection with a steam network, for generating steam for di f ferent purposes , or in corresponding applications . The method and the device may also be used for balancing operations of a steam network and an electrical network . In one embodiment the method and / or the device are used in connection with a steam network, for harmoni zing operations of energy networks , for balancing operations of a steam network and an electrical network, in industrial processes requiring steam, in steam generation plants or in combinations thereof .

[0029] Due to the invention, steam may be easi ly and ef ficiently generated for di f ferent purposes . By means of the invention, steam may be generated cost-ef fi- ciently also for small-scale applications . Additionally, the method and the device according to the invention may be easily deployed in connection with existing equipment or processes . Due to the invention, no separate boilers and / or heat exchangers are needed in generating steam .

[0030] In addition to generating steam, the invention may also be ef ficiently utili zed for harmoni zing operations between di fferent energy networks , preferably for example for balancing operations of a steam network and an electrical network .

[0031] LIST OF FIGURES

[0032] Fig . 1 illustrates one embodiment according to the invention for generating steam . Fig . 2 illustrates another embodiment according to the invention for generating steam.

[0033] EXAMPLES

[0034] The invention will now be described with detailed embodiment examples, referring to the accompanying figures.

[0035] Steam is generated in the processes as illustrated in Fig. 1 and 2. The process may be arranged in connection with a steam network or between two energy networks, e.g. between an electrical network and a steam network .

[0036] The device of Fig. 1 comprises at least one structure (2) formed of metal, and at least one inlet in the structure for feeding water (1) into the structure. Additionally, the structure comprises at least one channel (3) for providing a flow of water in the structure. The structure is a sealed thick metal pipe inside which the channel (3) has been arranged by drilling. Additionally, the structure comprises at least one electrical resistor (4) for heating the structure and vaporizing the water in the channel. The electrical resistor is arranged outside the structure, substantially in connection with the structure, and the electrical resistor is arranged to heat the structure. The device also comprises at least one measurement device (6) for measuring steam pressure in the channel, such as at the outlet of the channel, and at least one control device (7) for controlling the feed of water based on the pressure measurement and predetermined pressure limit values. The control device is in this example a controllable valve (7) for controlling the feed of water. Additionally, the device comprises at least one outlet for conducting steam (5) out from the structure. The steam (5) may be fed for example to a steam network.

[0037] The device of Fig. 2 comprises a structure (2) formed of a thick metal plate. Several channels (not shown in the figure ) are arranged inside the structure in flow communication with each other to provide a flow of water . Additionally, the structure comprises an inlet for feeding water ( 1 ) into a first channel of the structure from a lower part of the structure . The water is arranged to flow in the channels , i . e . in a system of channels , of the structure according to a predefined flow design . The structure is a sealed thick metal plate inside which the channels may be arranged e . g . by machining or drilling . Additionally, the structure comprises at least one electrical resistor ( 4 ) for heating the structure and vaporizing the water in the system of channels . The electrical resistor is arranged outside the structure , substantially in connection with the structure , and the electrical resistor is arranged to heat the structure . The device also comprises at least one measurement device ( 6 ) for measuring steam pressure and at least one control device ( 7 ) for controlling the feed of water based on the pressure measurement and predetermined pressure limit values . The control device is in this example a controllable valve ( 7 ) for controlling the feed of water . Additionally, the device comprises at least one outlet in an upper part of the structure for conducting steam ( 5 ) out from the structure, preferably via the last channel . The steam ( 5 ) may be fed for example to a steam network .

[0038] According to an example, the generation of steam is controlled in the process . Steam pressure is measured in the channel or at the outlet of the channel and the feed of water is controlled based on the pressure measurement and predetermined pressure limit values . The pressure limit values may be determined as being within a range suitable for the intended use, for example within the range of 3 - 16 bar . The steam pressure may be controlled in the structure by controlling the water level in the channel . The feed of water into the channel of the structure is controlled by means of a controllable valve . According to one example , the structure is heated by electrical resistors such that the temperature in the structure is 200 - 600 ° C, depending on the application .

[0039] According to one example, the device comprises several structures ( 2 ) in parallel or in series for vaporizing water, and the electrical resistors ( 4 ) are arranged between the structures . Each electrical resistor may heat one or two structures .

[0040] According to one example, the device comprises at least one frequency converter, preferably when the above described process is used between an electrical network and a steam network .

[0041] Example 1

[0042] In this example , steam is generated with the device as illustrated in Fig . 1 .

[0043] Water is fed into the device, steam is generated from the water, and the steam is conducted to a steam network in which the pressure is about 5 bar . Steam pressure is measured in the channel or at the outlet of the channel and the feed of water is controlled based on the pressure measurement and predetermined pressure limit values . The steam pressure is controlled by controlling the water level in the channel , and the feed of water into the channel is controlled by means of a controllable valve . I f the pressure rises above the limit values , water will not be fed . I f the pressure drops , water will be fed . The steam pressure controls the controllable water feed valve .

[0044] Example 2

[0045] In this example , steam is generated with the device as illustrated in Fig . 2 .

[0046] Water is fed into the device from a lower part of the structure , steam i s generated from the water, and the steam is conducted out from the structure from an upper part of the structure and is conducted to a steam network . Steam pressure is measured in the system of channels or immediately at the outlet of the last channel and the feed of water is controlled based on the pressure measurement and predetermined pressure limit values such that the pressure is maintained at a desired level . The steam pressure is controlled by controlling the water level in the system of channels or in a specific channel thereof , and the feed of water into the system of channels is controlled by means of a controllable valve . The structure is heated by an electrical resistor such that the temperature in the structure is about 500 ° C .

[0047] The method and the device for generating steam according to the invention are suitable in the form of di f ferent embodiments for use in generating most di fferent kinds of steam flows for di f ferent steam networks or processes requiring steam . The method and the device according to the invention are suitable in the form of di f ferent embodiments for use in most di f ferent kinds of applications .

[0048] The invention is not l imited to the above examples only, but many modi fications are possible within the scope of the inventive idea defined by the claims .

Claims

CLAIMS1 . A method for generating steam, c h a r a c t e r i z e d in that water (1) is fed into a structure (2) comprising at least one channel (3) for the flow of water and formed of metal, the structure is heated by means of an electrical element (4) , the water is vaporized in the channel within the structure, steam pressure is measured in the channel or after the channel and the feed of water is controlled based on the pressure measurement and predetermined pressure limit values, and steam (5) is conducted out from the structure.

2. The method according to claim 1, c h a r a c t e r i z e d in that the steam pressure is controlled in the structure (2) by controlling the water level in the channel (3) .

3. The method according to claim 1 or 2, c h a r a c t e r i z e d in that the feed of water (1) is controlled by means of a controllable valve (7) .4 . The method according to any of the claims 1 to 3, c h a r a c t e r i z e d in that the pressure limit values are determined as being 3 - 120 bar.

5. The method according to any of the claims 1 to 4, c h a r a c t e r i z e d in that the temperature in the structure is 150 - 900 °C.

6. The method according to any of the claims 1 to 5, c h a r a c t e r i z e d in that the electrical element (4) is arranged outside the structure (2) .7 . The method according to any of the claims 1 to 6, c h a r a c t e r i z e d in that the structure (2) is a thick pipe or metal plate.8 . A device for generating steam, c h a r a c t e r i z e d in that the device comprises at least one structure (2) formed of metal, at least one inlet in the structure for feeding water (1) into the structure and at least one channel (3) arranged inside the structure to provide a flow of water, and at least one electrical element (4) for heating the structure and vaporizing thewater in the channel, at least one measurement device (6) for measuring steam pressure in the channel or after the channel and at least one control device (7) for controlling the feed of water based on the pressure measurement and predetermined pressure limit values, and at least one outlet for conducting steam (5) out from the structure.

9. The device according to claim 8, c h a r a c t e r i z e d in that the device comprises at least one controllable valve (7) for controlling the feed of water .

10. The device according claim 8 or 9, c h a r a c t e r i z e d in that the structure (2) is a thick pipe or metal plate.

11. The device according to any of the claims 8 to 10, c h a r a c t e r i z e d in that the structure (2) comprises more than one channel (3) for the flow of water.

12. The device according to any of the claims 8 to 11, c h a r a c t e r i z e d in that the electrical element (4) is arranged outside the structure (2) , and is arranged to heat the structure.

13. The device according to any of the claims 8 to 12, c h a r a c t e r i z e d in that the device comprises at least one frequency converter.

14. The device according to any of the claims 8 to 13, c h a r a c t e r i z e d in that the device comprises more than one structure (2) and more than one electrical element (4) , and the electrical elements are arranged between the structures.

15. Use of a method, c h a r a c t e r i z e d in that the method according to any of the claims 1 - 7 is used in connection with a steam network, for harmonizing operations of energy networks, for balancing operations of a steam network and an electrical network, in industrial processes requiring steam, in steam generation plants, or in combinations thereof.

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