METHOD AND APPARATUS FOR CONTROLLING TEMPERATURE IN SELECTIVE CATALYTIC REDUCTION SYSTEMS

Abstract

An apparatus for use with a combustion apparatus and an associated Selective Catalytic Reduction (‘SCR’) device, comprises a temperature sensing device configured to measure the temperature of an exhaust from the combustion apparatus; and an injection unit configured to inject hydrogen into a feed of oxidizer to the combustion apparatus. An amount of hydrogen is added to an oxidiser feed of the combustion apparatus sufficient to reach a temperature in the exhaust of at least about 270° C.

Claims

1-16. (canceled)

17. A diesel engine comprising: a combustion apparatus for combustion of diesel fuel with an oxidizer, a Selective Catalytic Reduction (SCR) device for receiving exhaust from the combustion apparatus, the Selective Catalytic Reduction (SCR) device is configured for catalyzing conversion of nitrogen oxides in the exhaust into nitrogen and water, an air feed for feeding air into the combustion apparatus, an oxidizer feed for feeding hydrogen into the combustion apparatus, a temperature sensor configured to sense a temperature of the exhaust, a control unit configured to control the feeding of hydrogen into the combustion apparatus, wherein the control unit is configured to control the feeding of hydrogen into the combustion apparatus sufficient to reach a temperature in the exhaust of at least about 270° C.

18. The diesel engine according to claim 17, wherein the oxidizer feed is a part of an injection unit.

19. The diesel engine according to claim 18, wherein the injection unit further comprises a methanol feed and a water feed for controllably feeding methanol and/or water to an inlet of the combustion apparatus.

20. The diesel engine according to claim 18, wherein the injection unit is adapted for mixing hydrogen and air from the air feed prior to feeding to the combustion apparatus via an inlet.

21. The diesel engine according to claim 20, wherein the injection unit further comprises a methanol feed and a water feed for controllably feeding methanol and/or water to the inlet of the combustion apparatus.

22. The diesel engine according to claim 21, further comprising a combustion sensing device configured to monitor measure efficiency of the combustion apparatus, and wherein the control unit is configured to control operation of the injection unit based on input from the combustion sensing device.

23. The diesel engine according to claim 22, wherein the control unit comprises a user interface configured to display information, wherein the control unit is in communication with: the injection unit, the temperature sensor, and the combustion sensing device; and wherein the control unit is configured to present information on the user interface, the presented information comprises the temperature of the exhaust measured by the temperature sensor and the efficiency of the combustion apparatus measured by the combustion sensing device.

24. The diesel engine according to claim 23, wherein the presentation of information on the user interface comprises displaying the exhaust temperature on the user interface and causing a warning signal such as a warning message, a flashing light or an alarm sound.

25. The diesel engine according to claim 22, wherein the injection unit is configured to inject methanol and/or water into the oxidizer feed; and wherein the control unit is configured to control the injection of hydrogen, methanol and water based on an exhaust temperature measured by the temperature sensor and based on a combustion efficiency measured by the combustion sensing device.

26. The diesel engine according to claim 25, wherein that the control unit has: an automated mode in which the control unit automatically controls and/or regulates injection of hydrogen, methanol and water based on an input including exhaust temperature received from the temperature sensor device and combustion efficiency received from the combustion sensing device; and a manual mode in which a user may manually control and/or regulate injection of hydrogen based on an input.

27. The diesel engine according to claim 26, wherein the input is an exhaust temperature received from the temperature sensor and combustion efficiency received from the combustion sensing device, and being displayed on the user interface.

28. A method for operating a diesel engine comprising a combustion apparatus for combustion of diesel fuel with an oxidizer, and a Selective Catalytic Reduction (SCR) device for receiving exhaust from the combustion apparatus and configured for catalyzing conversion of nitrogen oxides in the exhaust into nitrogen and water, the method comprises: feeding air to the combustion apparatus; measuring the temperature of the exhaust from the combustion apparatus; and controlling injection of hydrogen into the combustion apparatus; wherein the injection of hydrogen into the combustion apparatus is controlled to be sufficient to reach a temperature in the exhaust of at least about 270° C.

29. The method according to claim 28, further comprising: measuring combustion efficiency in the combustion apparatus; and adjusting an oxidizer feed based on the measured combustion efficiency, the oxidizer feed adds a mixture of hydrogen, methanol and water to an inlet of the combustion apparatus.

30. The method according to claim 29, wherein the adjusting the amount and/or ratio of hydrogen, methanol and water added to the oxidizer feed is based on the measured temperature and on the measured combustion efficiency.

31. The method according to claim 30, wherein the ratio of hydrogen, methanol and water is a:b:c, each of a, b and c being ≥0, wherein the method further comprising controlling and/or regulating the amount of hydrogen, methanol and water, and/or the ratios a:b:c, so as to control and/or regulate the temperature of the exhaust and the efficiency of the combustion apparatus.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0085] Embodiments of the present disclosure will now be given by way of example only, and with reference to the accompanying drawings, which are:

[0086] FIG. 1 illustrates an apparatus according to a first embodiment of the invention;

[0087] FIG. 2 illustrates an apparatus according to a second embodiment of the invention;

[0088] FIG. 3 illustrates a method according to one embodiment of the invention;

[0089] FIG. 4 illustrates a method according to another embodiment of the invention; and

[0090] FIG. 5 illustrates a method according to yet another embodiment of the invention.

DETAILED DESCRIPTION OF DRAWINGS

[0091] Referring to FIG. 1 there is shown a schematic representation perspective view of an apparatus, generally designated 10, according to a first embodiment.

[0092] The apparatus 10 is associated with a combustion apparatus 20, which in this embodiment is a diesel engine.

[0093] The combustion apparatus 20 is associated with a Selective Catalytic Reduction (‘SCR’) device 30. The SCR device 30 is configured to treat exhaust gases 25 from the combustion apparatus 20, and in particular to catalyse the conversion of nitrogen oxides, using urea or ammonia as a reductant, into nitrogen (N2) and water (H2O). In use, the combustion apparatus is fed fuel such as diesel fuel (not shown), and an oxidiser which in this embodiment is an air feed 21.

[0094] It will be appreciated that, in other embodiments, the apparatus may be used in combination with other combustion apparatus 20 which may be associated with an SCR device, including for example industrial boilers or the like, and is thus not limited for use with diesel engines specifically.

[0095] The apparatus 10 includes a temperature sensing device 40 configured to measure the temperature of the exhaust 25 from the combustion apparatus 20.

[0096] The apparatus 10 also includes an injection unit 50 configured to inject hydrogen 51 into the air feed 21 which is fed to the combustion apparatus 20. As shown in FIG. 1, the injection of hydrogen is performed before injection of air feed 21 to the combustion apparatus 20, such that, when hydrogen 51 is added and/or injected, it is mixed with the air feed 21 to provide a mixture 22 of air and hydrogen.

[0097] Typically, for the SCR device 30 to convert the environmental harmful nitrogen oxides into pure nitrogen and water effectively, the operating temperature in the SCR device 30 should reach a minimum temperature, typically at least 280° C. - 300° C., e.g. between 280° C. and 325° C., for the process to work. If the temperature of the exhaust 25 from combustion apparatus 20 is too low, the reduction of NOx compounds may not occur.

[0098] The inventors have discovered that, by adding hydrogen 51 to the feed 22, an increase in the temperature of the exhaust 25 may be obtained compared to the temperature of the exhaust 25 using an air feed 21 free of additional hydrogen.

[0099] Thus, the apparatus 10 has a control unit 60 configured to control operation of the injection unit 50 so as to control and/or regulate injection of hydrogen 51. The control unit 60 has a user interface 62 which displays information, including for example the temperature of the exhaust 25 measured by the temperature sensing device 40. The user interface 62 can also receive a input from a user s as to control the injection unit 50.

[0100] The control unit 60 is in communication with the injection unit 50 and the temperature sensing device 40.

[0101] The control unit has an automated mode in which the control unit 60 automatically controls and/or regulates injection of hydrogen 51 based on an input, e.g. exhaust temperature received from the temperature sensing device 40. The control unit 60 also has a manual mode in which a user may manually control and/or regulate injection of hydrogen 51 based on an input, e.g. exhaust temperature received from the temperature sensing device 40. In this embodiment, the control unit 60 can be switched between a manual mode and an automatic mode.

[0102] In use, when the temperature of the exhaust 25 is below a predetermined value (which may depend on the particular type of combustion apparatus 20 and/or on the SCR device 30), the control unit 60 receives a signal indicating that the temperature is below the predetermined or threshold value. This may be done by displaying the temperature on the user interface 62 and/or causing a warning signal such as a warning message, a flashing light or an alarm sound. The control unit 60 then sends a command (automatically or manually) to the injection unit 50 causing partial or full opening of valve 56 in the hydrogen supply line 51 and thus injection of hydrogen 51 in the feed 22. The hydrogen supply line 51 is connected to a source of hydrogen (not shown) which can be a hydrogens tank or container, or an on-demand hydrogen source such as a hydrolysis unit.

[0103] When the temperature of the exhaust 25 is at or around a/the predetermined value or within a/the predetermined range, the control unit 60 receives a signal indicating that the temperature is at or around a/the predetermined value or within a/the predetermined range. This may be done by displaying the temperature on the user interface 62 and/or triggering an associated signal such as a written message, a coloured light or an associated sound. The control unit 60 then sends a command (automatically or manually) to the injection unit 50 causing either partial or full closure of the valve 56 in the hydrogen supply line 51 and thus either reduced injection or interruption of the injection of hydrogen 51 in the feed 22.

[0104] The amount of hydrogen injected, e.g. the extent/degree of the opening or closure of the valve 56 may be determined and/or may be based on the extent of the variation between the exhaust temperature measured by the sensor 40 and the predetermined target temperature or temperature range for the SCR device 30.

[0105] Thus, referring to FIG. 3, there is shown a method 200 of controlling and/or regulating the temperature of an exhaust from a combustion apparatus. The method 200 comprises measuring and/or monitoring the temperature of the exhaust 210, and controllably feeding 220 an amount of hydrogen to an inlet of the combustion apparatus sufficient to adjust the temperature in the exhaust. Advantageously, step 220 comprises feeding an amount of hydrogen to an inlet of the combustion apparatus sufficient to adjust the temperature in the exhaust, above a predetermined value and/or within a predetermined range.

[0106] Referring now to FIG. 2, there is shown a perspective view of an apparatus, generally designated 110, according to a second embodiment. The apparatus is generally similar to the apparatus 10 of FIG. 1, like parts being denoted by like numerals, but incremented by ‘100’.

[0107] However, in this embodiment, the apparatus 110 also includes a combustion sensing device 145 configured to monitor the efficiency of the combustion apparatus 120. In this embodiment, the combustion sensing device 145 includes one or more temperature sensors configured to measure temperature in the combustion apparatus, e.g. combustion chamber thereof and one or more pressure sensors configured to measure pressure in the combustion apparatus, e.g. combustion chamber thereof. However, in other embodiments, the combustion sensing device 145 may include high accuracy flowmeters associated with a fuel inlet so as to measure volume and/or flow rate of fuel to the combustion apparatus.

[0108] The injection unit 150 is configured to inject hydrogen 151, methanol 152 and/or water 153 into the air feed 121 which is fed to the combustion apparatus 120. As shown in FIG. 2, the injection of hydrogen, methanol and water is performed before injection of air feed 121 to the combustion apparatus 120, such that, when hydrogen 151, methanol 152 and/or water 153 is/are added and/or injected, such is/are mixed with the air feed 121 to provide a mixture 122.

[0109] In FIG. 2, the apparatus 110 also includes another optional feed 154 which may be arranged to adjust any further specific parameter of the combustion process.

[0110] Each of the hydrogen supply 151, methanol supply 152 and water supply 153 is associated with a valve 156 configured to control and/or regulate the flow of hydrogen, methanol or water in its respective supply line.

[0111] The control unit 160 is configured to control operation of the injection unit 150 so as to control and/or regulate injection of hydrogen 151, methanol 152 and water 153. The user interface 162 displays information, including for example the temperature of the exhaust 125 measured by the temperature sensing device 140 and the efficiency of the combustion apparatus 120 measured by the combustion sensing device 145.

[0112] The control unit 160 is in communication with the injection unit 150 and each of the temperature sensing device 140 and combustion sensing device 145.

[0113] The control unit 160 can have an automated mode in which the control unit 160 automatically controls and/or regulates injection of hydrogen 151, methanol 152 and water 153 based on an input, e.g. exhaust temperature received from the temperature sensing device 140 and the efficiency of the combustion apparatus 120 measured by the combustion sensing device 145. The control unit 160 can also have a manual mode in which a user may manually control and/or regulate injection of hydrogen 151, methanol 152 and water 153 based on an input, e.g. exhaust temperature received from the temperature sensing device 140 and the efficiency of the combustion apparatus 120 measured by the combustion sensing device 145. In this embodiment, the control unit 160 can be switched between a manual mode and an automatic mode.

[0114] In use, the control unit 160 controls operation of the injection unit 150 such that hydrogen, methanol and water are injected or added in a ratio a:b:c, wherein a, b and c are the relative amounts of hydrogen, methanol and water added to the air feed 121 to create feed mixture 122. The injection unit 150 injects and/or adds hydrogen, methanol and water to the feed 121 in an amount, e.g. weight %, of x, y and z, relative to the total amount, e.g. weight, of the air feed 121, to create feed mixture 122.

[0115] Advantageously, the control unit 160 is configured to control and/or regulate injection of hydrogen 151, methanol 152 and/or water 153, for example by adjusting the values x, y and z, based on an input, e.g. exhaust temperature received from the temperature sensing device 140 and/or combustion efficiency received from the combustion sensing device 145.

[0116] Similarly to the apparatus described in FIG. 1, when the temperature of the exhaust 125 is below a predetermined value (which may depend on the particular type of combustion apparatus 120 and/or on the SCR device 130), the control unit 160 receives a signal indicating that the temperature is below the predetermined or threshold value. This may be done by displaying the temperature on the user interface 162 and/or causing a warning signal such as a warning message, a flashing light or an alarm sound. The control unit 160 then sends a command (automatically or manually) to the injection unit 150 causing partial or full opening of valve 156 in the hydrogen supply line 151 and thus injection of hydrogen 151 in the feed 122. The hydrogen supply line 151 is connected to a source of hydrogen (not shown) which can be a hydrogen tank or container, or an on-demand hydrogen source such as a hydrolysis unit.

[0117] When the temperature of the exhaust 125 is at or around a/the predetermined value or within a/the predetermined range, the control unit 160 receives a signal indicating that the temperature is at or around a/the predetermined value or within a/the predetermined range. This may be done by displaying the temperature on the user interface 162 and/or triggering an associated signal such as a written message, a coloured light or an associated sound. The control unit 160 then sends a command (automatically or manually) to the injection unit 150 causing either partial or full closure of the valve 156 in the hydrogen supply line 151 and thus either reduced injection or interruption of the injection of hydrogen 151 in the feed 122.

[0118] The amount of hydrogen injected, e.g. the extent/degree of the opening or closure of the valve 156 may be determined and/or may be based on the extent of the variation between the exhaust temperature measured by the sensor 140, and the predetermined target temperature or temperature range for the SCR device 130.

[0119] When the combustion efficiency measured by the combustion sensor device 145 is relatively low, e.g. below a predetermined threshold, the control unit 160 receives a signal indicating that the efficiency is below the predetermined or threshold value. This may be done by displaying the efficiency on the user interface 162 and/or causing a warning signal such as a warning message, a flashing light or an alarm sound. The control unit 160 then sends a command (automatically or manually) to the injection unit 150 causing partial or full opening of valve 156 in the hydrogen supply line 151 and/or in the methanol supply line 152 and thus injection of hydrogen 151 and/or methanol 152 in the feed 122. The methanol supply line 152 is connected to a source of methanol (not shown) which can be typically a methanol tank or container. This causes an increase in the amount and/or proportion of hydrogen and/or methanol in the feed 122 of the combustion apparatus 120.

[0120] When the combustion efficiency is relatively low, e.g. below a predetermined threshold, and the temperature of the exhaust is below a/the desired level or range, the control unit 160 sends a command (automatically or manually) to the injection unit 150 causing partial or full opening of valve 156 in the hydrogen supply line 151.

[0121] When the combustion efficiency is relatively low, e.g. below a predetermined threshold, and the temperature of the exhaust is at or above a/the desired level or range, the control unit 160 sends a command (automatically or manually) to the injection unit 150 causing partial or full opening of valve 156 in the methanol supply line 152.

[0122] When the combustion efficiency is relatively high, e.g. at or above a predetermined threshold, and the temperature of the exhaust is at or above a/the desired level or range, the control unit 160 sends a command (automatically or manually) to the injection unit 150 causing partial or full opening of valve 156 in the water supply line 153.

[0123] Thus, the control unit 160 controls the injection of each of hydrogen 151, methanol 152 and water 153, so as to control the amounts and/or ratios of hydrogen, methanol and water in the feed 122, in orderto control the temperature of the exhaust 125 to optimise the SCR process in the SCR apparatus 130, and to improve or optimise efficiency in the combustion apparatus 120.

[0124] Referring to FIG. 4, there is shown a method 300 of controlling and/or regulating the temperature of an exhaust from a combustion apparatus. The method 300 comprises measuring and/or monitoring the temperature of the exhaust 310, and controllably feeding 320 an amount of hydrogen, methanol and water to an inlet of the combustion apparatus sufficient to adjust the temperature in the exhaust. Advantageously, step 320 comprises feeding an amount of hydrogen, methanol and water to an inlet of the combustion apparatus sufficient to adjust the temperature in the exhaust, above a predetermined value and/or within a predetermined range.

[0125] Referring now to FIG. 5, there is shown another embodiment of a method 400 for controlling and/or regulating the temperature of an exhaust from a combustion apparatus and improving efficiency of a combustion process. The method 400 comprises measuring and/or monitoring the temperature of the exhaust 410. The method also comprises measuring the combustion efficiency of the combustion process 420. The method then comprises controllably feeding 430 an amount of hydrogen, methanol and water to an inlet of the combustion apparatus sufficient to adjust the temperature in the exhaust and optimise combustion efficiency. Advantageously, step 420 comprises feeding an amount of hydrogen, methanol and water to an inlet of the combustion apparatus sufficient to adjust the temperature in the exhaust, above a predetermined value and/or within a predetermined range, and to adjust the combustion efficiency in the combustion apparatus above a predetermined value and/or within a predetermined range.

[0126] It will be appreciated that the embodiments of the invention hereinbefore described are given by way of example only and are not meant to limit the scope thereof in any way.