Apparatus and system for reducing oxygen concentration in main gas stream

Abstract

There is provided an apparatus and system for reducing oxygen concentration in a main gas stream, comprising: a main gas stream channel having a main gas inlet for the main gas stream and a main gas outlet for the deoxygenated main gas stream; a reaction gas flow channel comprising a reaction gas inlet at a first end for a flow of reaction gas and connected at a connection location to the main gas flow channel at a second end so as to allow injection of reaction gas into the main gas flow channel, the reaction gas flow channel further comprising a mass flow control device downstream of the reaction gas inlet; a reactor member arranged in the main gas flow channel downstream of the connection location and upstream of the main gas flow outlet; and a control unit adapted to control the mass flow control device based on an inlet process condition of the main gas stream and / or an outlet process condition of the deoxygenated main gas stream so as to control the injection flow of the reaction gas to a desired reaction gas flow. The device and system are more efficient and improve performance and life.

Description

Technical Field

[0001] This disclosure relates to an apparatus and system for reducing the oxygen content in a main gas stream (such as a gas stream primarily composed of nitrogen or carbon dioxide), and particularly to an apparatus or system comprising a control unit for controlling the injection flow rate of a reactant gas into said main gas stream. Background Technology

[0002] Deoxygenation devices remove oxygen from the main gas stream. They do this by forcing oxygen through reactor components (such as a catalytic bed) to react with the reactant gas, which reduces the reaction barrier between oxygen and the reactant gas. For the reactant gas, there are two possible solutions:

[0003] 1. The reactant gas is the same as the main gas.

[0004] 2. The reactant gas is different from the main gas.

[0005] In the second type of solution, the reactant gas must be injected into the main gas stream before entering the reactor components. The amount of reactant gas injected is typically calculated based on rated conditions and the stoichiometric relationship between oxygen and the reactant gas; that is, assuming the reaction is perfect and all oxygen is expected to react. However, if the application does not require complete deoxygenation, this can lead to overuse of the reactant gas, or similarly, if the application does require it, deoxygenation may be insufficient because removing all oxygen requires a slightly overstoichiometric dose of reactant gas. This makes the entire deoxygenation process correspondingly inefficient or unsatisfactory.

[0006] Furthermore, the reactant gas source is typically not considered in the operation of deoxygenation units. Depending on the type of source, this can lead to on / off control strategies that can significantly impact the performance and lifespan of the reactant gas source / generator.

[0007] There is a need for a second type of improved solution in industry. Utility Model Content

[0008] The purpose of this disclosure is to provide a more efficient device and system for reducing the oxygen concentration in the main gas stream.

[0009] In a first aspect of this disclosure, an apparatus for reducing the oxygen concentration in a main gas or main gas stream is disclosed, the system comprising:

[0010] a. A main gas flow channel having a main gas flow inlet for the main gas flow and a main gas flow outlet for the deoxygenated main gas flow;

[0011] b. A reaction gas flow channel, the reaction gas flow channel including a reaction gas inlet for reaction gas flow at a first end and a connection at a second end to (e.g., fluid connection to) a main gas flow channel to allow the injection of reaction gas into the main gas flow channel, the reaction gas flow channel including a mass flow control device downstream of the reaction gas inlet;

[0012] c. A reactor component arranged in the main gas flow channel downstream of the connection point and upstream of the main gas flow outlet;

[0013] d. A control unit adapted to control the mass flow control device based on the inlet process conditions of the main gas flow and / or the outlet process conditions of the deoxygenated main gas flow, so as to control the injection flow rate of the reactant gas injected into the main gas flow in the main gas flow channel to the desired reactant gas flow rate.

[0014] The advantages are that reactant gases can be used more efficiently and overuse can be avoided. Furthermore, the performance and lifespan of the associated reactant gas generators are expected to be improved.

[0015] A mass flow control device may include, for example, at least one valve.

[0016] Reactor components may include, for example, a reactor chamber or vessel, such as a catalyst bed.

[0017] According to a preferred embodiment, the control unit is adapted to calculate the required flow rate of the reactant gas to be injected into the main gas flow based on the main gas flow at the main gas inlet, the oxygen concentration at the main gas inlet, and the required ratio of the reactant gas concentration to the oxygen concentration.

[0018] For example, the required ratio of the concentration of the reactant gas to the concentration of oxygen can be constant.

[0019] Alternatively, the desired ratio of reactant gas concentration to oxygen concentration can depend on the target oxygen concentration of the deoxygenated main gas stream.

[0020] According to a preferred embodiment, the desired ratio of reactant gas concentration to oxygen concentration depends on the flow load of the device (or system according to the second aspect) for reducing the oxygen concentration in the main gas or main gas stream. The flow load of the device (or system) for reducing the oxygen concentration in the main gas or main gas stream can be expressed, for example, as a fraction of the maximum flow rate or nominal design flow rate of the device (or system) for reducing the oxygen concentration in the main gas or main gas stream, e.g., a percentage.

[0021] According to a preferred embodiment, the control unit is adapted to calculate the required flow rate of the reactant gas to be injected into the main gas stream based on the actual oxygen concentration of the deoxygenated main gas stream.

[0022] According to a preferred embodiment, the control unit is adapted to calculate the required flow rate of reactant gas to be injected into the main gas stream based on the actual reactant gas concentration of the deoxygenated main gas stream.

[0023] According to a preferred embodiment, the control unit is adapted to calculate the required flow rate of reactant gas to be injected into the main gas stream based on the actual oxygen concentration and the actual reactant gas concentration of the deoxygenated main gas stream.

[0024] According to a preferred embodiment, the mass flow control device controlled by the control unit includes providing a first flow setpoint value of the desired reactive gas flow to be injected to the mass flow control device at least periodically or continuously.

[0025] According to a preferred embodiment, the control unit is also adapted to control the flow rate of the reaction gas entering the reaction gas flow channel from the reaction gas inlet.

[0026] In a second aspect of this disclosure, a system for reducing the oxygen concentration in a main gas stream is disclosed. The system includes means for reducing the oxygen concentration in the main gas stream according to any of the embodiments of the first aspect, and further includes a reactant gas generator connected to a reactant gas inlet, wherein the control unit is also adapted to control the flow rate of the reactant gas generator.

[0027] According to a preferred embodiment, the reaction gas generator is fluidly connected to the reaction gas inlet.

[0028] According to a preferred embodiment, the system further includes a reaction gas buffer disposed downstream of the reaction gas generator and upstream of the reaction gas inlet.

[0029] The reaction gas generator can be, for example, a hydrogen or carbon dioxide generator, such as a hydrogen electrolyzer.

[0030] According to a preferred embodiment, controlling the flow rate of the reaction gas generator includes, preferably, the control unit providing the reaction gas generator with a second flow rate setpoint value for the reaction gas flow to be generated at least periodically or continuously.

[0031] For the purposes of this disclosure, the control unit may be a single control unit, or may include two or more distributed separate control units. This has been abstracted throughout this specification. For example, a control unit suitable for controlling the flow rate of the reactant gas generator and a control unit suitable for controlling the mass flow control device to control the injection flow rate of the reactant gas injected into the main gas flow in the main gas flow channel may be the same control unit or different control units. Preferably, these control units are the same single central control unit.

[0032] According to a preferred embodiment, the second flow setpoint value is a preferred time-dependent function of at least one first flow setpoint or a set of first flow setpoints, such as a polynomial function or a linear function.

[0033] The second flow setpoint value can be based on or derived from at least one first flow setpoint or a set of first flow setpoints. The second flow setpoint value can be a corresponding first setpoint value multiplied by, for example, a time-related scalar value.

[0034] According to a preferred embodiment, the second flow setpoint value is a preferred time-dependent function of the reaction gas pressure measured in the reaction gas flow channel upstream of the mass flow control device or in the reaction gas generator.

[0035] According to a preferred embodiment, the function includes a polynomial correlation of the reactive gas pressure measured in the reactive gas flow channel upstream of the mass flow control device or in the reactive gas generator.

[0036] According to a preferred embodiment, the function includes a linear correlation of the reaction gas pressure measured in the reaction gas flow channel upstream of the mass flow control device or in the reaction gas generator.

[0037] According to a preferred embodiment, the second flow setpoint value is a preferred time-dependent function of the predicted availability of preferred low-carbon-emission electricity over time.

[0038] According to a preferred embodiment, the function includes a polynomial correlation of the predicted availability of electricity over time.

[0039] According to a preferred embodiment, the function includes a linear correlation of the predicted availability of electricity over time.

[0040] According to a preferred embodiment, the second flow setpoint value is a preferred time-dependent function of the predicted cost of energy that varies over time.

[0041] According to a preferred embodiment, the function includes a polynomial correlation of the predicted cost of energy that varies over time.

[0042] According to a preferred embodiment, the function includes a linear correlation between the predicted cost of energy and its variation over time.

[0043] According to a preferred embodiment, the main gas or main gas stream primarily comprises nitrogen or carbon dioxide. Preferably, it includes an initial amount of oxygen that needs to be reduced or removed from the main gas stream.

[0044] According to a preferred embodiment, the reaction gas stream mainly comprises hydrogen or carbon monoxide.

[0045] As will be appreciated by those skilled in the art, the features and advantages disclosed in one aspect of this disclosure, with necessary modifications, are also implicitly disclosed in other aspects. Attached Figure Description

[0046] This disclosure will be further illustrated by the following description and accompanying drawings.

[0047] Figure 1 This is a schematic overview of a system according to a preferred embodiment of the present disclosure.

[0048] Figure 2 This is a schematic overview of feedforward control of a reactive gas flow according to a preferred embodiment of the present disclosure.

[0049] Figure 3 The desired ratio of reactant gas concentration to oxygen concentration according to a preferred embodiment of the present disclosure is shown in relation to a target oxygen concentration.

[0050] Figure 4 The desired ratio of reactant gas concentration to oxygen concentration according to a preferred embodiment of the present disclosure is shown in relation to the flow load of the apparatus, wherein the maximum flow load of the apparatus represents 100% load.

[0051] Figure 5 Feedback control of the reactant gas stream based on the oxygen concentration of the deoxygenated main gas stream, according to a preferred embodiment of the present disclosure, is illustrated.

[0052] Figure 6 This is a schematic overview of feedforward and feedback control of the reactant gas stream based on the oxygen concentration of the deoxygenated main gas stream, according to a preferred embodiment of the present disclosure.

[0053] Figure 7 This is a schematic overview of feedback control of the reactant gas flow based on the reactant gas concentration of the deoxygenated main gas flow according to a preferred embodiment of the present disclosure.

[0054] Figure 8 This is a schematic overview of feedforward and feedback control of the reactant gas flow based on the reactant gas concentration of the deoxygenated main gas flow, according to a preferred embodiment of the present disclosure.

[0055] Figure 9 This is a schematic overview of feedback control of the reactant gas stream based on the oxygen concentration of the deoxygenated main gas stream and the reactant gas concentration of the deoxygenated main gas stream, according to a preferred embodiment of the present disclosure.

[0056] Figure 10This is a schematic overview of feedforward and feedback control of the reactant gas stream using the oxygen concentration of the deoxygenated main gas stream and the reactant gas concentration of the deoxygenated main gas stream according to a preferred embodiment of the present disclosure.

[0057] Figure 11 c is shown according to a preferred embodiment of the present disclosure. p The constant relationship between the pressure of the reacting gas and the pressure of the reacting gas.

[0058] Figure 12 c is shown according to a preferred embodiment of the present disclosure. p The pressure band relationship between the pressure of the reacting gas and the pressure band of the reacting gas.

[0059] Figure 13 c is shown according to a preferred embodiment of the present disclosure. p The precise operating pressure band relationship between the pressure of the reactant gas and the pressure of the reactant gas.

[0060] Figure 14 c is shown according to a preferred embodiment of the present disclosure. p The S-shaped operating pressure band relationship between the pressure of the reactant gas and the pressure of the reactant gas. Detailed Implementation

[0061] This disclosure will be described with respect to specific embodiments and with reference to certain accompanying drawings, but is not limited thereto; rather, it is limited only by the claims. The described drawings are illustrative only and not restrictive. In the drawings, some elements may be enlarged rather than drawn to scale for illustrative purposes. Dimensions and relative dimensions do not necessarily correspond to an actual reduction in practice with respect to this disclosure.

[0062] Furthermore, the terms first, second, third, etc., used in the specification and claims are used to distinguish similar elements and are not necessarily used to describe sequential or chronological order.

[0063] Although referred to as “preferred,” the various embodiments should be construed as examples of how this disclosure may be implemented, rather than as limiting the scope of this disclosure.

[0064] Figure 1 Preferred embodiments of an apparatus 1 and a system 9 for reducing the oxygen concentration in a main gas or main gas flow (or main gas stream) 1000 are disclosed. The apparatus 1 includes a main gas flow channel 10 having a main gas flow inlet 101 for the main gas flow 1000 and a main gas flow outlet 102 for the deoxygenated main gas flow 1000*. It should be understood that the deoxygenated main gas flow 1000* should be considered as a main gas flow with an oxygen content lower than the initial main gas flow 1000. This deoxygenated main gas flow may still contain a certain, but at least reduced, amount of oxygen, the amount depending on the actual conditions and intended use of the deoxygenated main gas flow 1000* downstream of the apparatus 1 or system 9.

[0065] The apparatus 1 includes a reaction gas flow channel 20 for a reaction gas flow 2000, the reaction gas flow channel including a reaction gas inlet 201 at a first end and connected (preferably fluidly connected) to a main gas flow channel at a connection point C at a second end 202 (reaction gas outlet), for example to allow the injection of reaction gas into the main gas flow channel 10. The reaction gas flow channel 20 includes a mass flow control device 21 for controlling the reaction gas flow located downstream of the reaction gas inlet 201.

[0066] The apparatus 1 includes a reactor component 3 arranged in the main gas flow channel 10 downstream of the connection position C and upstream of the main gas flow outlet 102.

[0067] The apparatus 1 and system 9 also include a control unit 4, which is adapted to control the mass flow control device 21 based on the inlet process conditions of the main gas flow 1000 and / or the outlet process conditions of the deoxygenated main gas flow 1000*, so as to control the injection flow rate of the reactant / reaction gas injected into the main gas flow 1000 in the main gas flow channel 10 to the desired reaction gas flow rate.

[0068] Preferably, system 9 further includes a reactive gas generator 222 connected, preferably fluidly connected, to the reactive gas inlet 201, and control unit 4 is also adapted to control the flow rate of the reactive gas generator 222. System 9 may also include a reactive gas buffer 22 upstream of the reactive gas inlet 201 (and, for example, upstream of the mass flow control device 21) and downstream of the reactive gas generator 222. It should be noted that the reactive gas buffer 22 may be a dedicated buffer container or simply the internal volume of the pipe connecting the reactive gas generator 222 to device 1 (e.g., to the reactive gas inlet 201 of the device).

[0069] The device 1 and system 9 preferably include measuring components, such as sensors arranged in various locations.

[0070] For example, a pressure sensor S1 can be provided and arranged to measure the pressure of the reaction gas in or downstream of the reaction gas generator 222 (e.g., also upstream of the reaction gas inlet 201 or upstream of the reaction gas buffer 22).

[0071] For example, at a location downstream of the main gas inlet 101 and upstream of the connection point C, an oxygen sensor S2 may be provided and arranged to measure the oxygen content of the main gas flow 1000, and / or a pressure sensor S3 may be provided and arranged to measure the pressure of the main gas flow 1000, or a flow measurement component (such as a flow meter or sensor S4) may be provided and arranged to measure the gas flow rate of the main gas flow 1000.

[0072] For example, an oxygen sensor S5 and / or a reactant sensor S6 can be provided and arranged to measure the oxygen concentration and / or reactant gas concentration in the deoxygenated main gas stream 1000* downstream of the reactor component 3 and upstream of the main gas stream outlet 102.

[0073] Any of the aforementioned sensors is adapted to communicate the measured value to the control element or unit 4, and the control unit 4 is configured and adapted to receive the measured value from the sensors present in the respective sensors S1 to S6.

[0074] The advantages of the embodiments disclosed herein are that the reactant gas can be used more efficiently and overuse can be avoided. Furthermore, the performance and lifespan of the associated reactant gas generator 222 are expected to be improved.

[0075] The objective of embodiments of this disclosure is to calculate the amount of reactant gas required to deoxygenate the main gas stream 1000 based on multiple process conditions, so as to continuously match the deoxygenation requirements, reduce reactant gas consumption, and operate the reactant gas source efficiently based on the calculated values.

[0076] For example, this offers the following advantages:

[0077] 1. Ensure that Unit 1 continuously meets export requirements;

[0078] 2. The consumption of reactant gases is minimized;

[0079] 3. The reaction gas generator 222 is operated efficiently.

[0080] In a preferred embodiment, the reaction gas is hydrogen or carbon monoxide. In the former case, the required amount of reaction gas can be fed to a reaction gas generator 222, which is implemented as a hydrogen generator, or in a preferred embodiment, an electrolytic cell.

[0081] The operation and control of the gas used for deoxygenation rely on a central controller 4, which transmits the flow setpoint to a mass flow control device 21, which injects a corresponding amount of the reactant gas flow into the main gas flow 1000. This flow setpoint is calculated based on inlet and / or outlet process conditions sensed by appropriate devices, as explained in subsequent paragraphs.

[0082] Additionally, the central controller 4 preferably transmits a generator setpoint equivalent to the flow rate of the reactant gas that must be produced by the reactant gas generator 222. This setpoint is directly related to the flow rate setpoint and, among other things, depends on the reactant gas process conditions. This operation is described in more detail in the following paragraphs.

[0083] A. Control of the reaction gas flow in the deoxygenation unit

[0084] The control of the flow setpoint (i.e., the target flow rate of the reactant gas transmitted to the mass flow control device 21 and, if the reactant gas generator 222 is available, may be used to calculate the generator setpoint) is based on the inlet process conditions of the main gas flow 1000 and / or the outlet process conditions of the deoxygenated main gas flow 1000*. The following control scheme is proposed.

[0085] 1. Control the flow setpoint based on feedforward control.

[0086] In the feedforward control scheme, the required amount of reactant gas is continuously calculated based on the inlet process conditions of the main gas flow 1000, more specifically, the main gas flow 1000 at the main gas flow inlet 101, the oxygen concentration at the main gas flow inlet 101, and the required ratio of reactant gas concentration to oxygen concentration. This is in Figure 2 The block diagram depicts a calculated value of the reactive gas flow rate, labeled "reactive gas flow rate target," representing the flow rate setpoint and subsequently transmitted to the mass flow control device 21.

[0087] It should be noted that the maximum limit for the oxygen concentration at the main gas inlet 101 is added using the maximum inlet O2 concentration parameter. Similarly, the target reactant gas flow rate is limited by the minimum reactant gas flow rate parameter. Neither of these conditions is mandatory throughout the control system.

[0088] The desired ratio of reactant gas concentration to oxygen concentration allows for the adjustment of the reactant gas flow rate target based on the following methods.

[0089] In the first feedforward control scheme, the desired ratio of the reactant gas concentration to the oxygen concentration is maintained at a fixed value, which can be the stoichiometric coefficient in the reaction between the reactant gas and oxygen.

[0090] In another control scheme, the desired ratio of reactant gas concentration to oxygen concentration depends on the target oxygen concentration of the deoxygenated main gas stream 1000*.

[0091] Figure 3 It depicts the trend that the lower the target oxygen concentration of the deoxygenated main gas stream 1000*, the higher the required ratio of the deoxygenated main gas stream 1000*.

[0092] Another variation for adjusting the desired ratio of reactant gas concentration to oxygen concentration depends on the flow load of device 1. It is well known that technological limitations of flow sensing devices cause measurement biases in low flow regions. These biases can be compensated for by the desired ratio of reactant gas concentration to oxygen concentration.

[0093] As an example, Figure 4 The study depicted a trend that the lower the flow load of device 1, the higher the required ratio of reactant gas concentration to oxygen concentration.

[0094] In another feedforward control scheme, the oxygen concentration target and the flow load of device 1 can be combined to perform composite regulation of the desired ratio of reactant gas concentration to oxygen concentration.

[0095] 2. The flow setpoint is controlled based on feedback control using the actual oxygen concentration of the deoxygenated main gas flow.

[0096] In this feedback control scheme, the actual oxygen concentration of the deoxygenated main gas flow is used in the control of the reactant gas flow rate. This means that controller unit 4 can provide feedback control in the form of PID control or its variants (P, PI, ...).

[0097] exist Figure 5 The block diagram depicts the control scheme, in which the calculated value of the reactive gas flow rate, labeled "reactive gas flow rate target", represents the flow rate setpoint and is subsequently transmitted to the mass flow control device 21.

[0098] The baseline value (variable γ) is used to minimize reactant gas consumption, as this value will be systematically corrected for errors in the oxygen concentration of the deoxygenated main gas stream. γ may depend on the nominal flow rate of device 1, or may, for example, be equal to the minimum reactant gas flow rate.

[0099] Multiply the error in the oxygen concentration of the deoxygenated main gas stream by the total outlet gas flow rate, which is the sum of the main gas flow rate at the main gas inlet and the injected reactant gas flow rate. This multiplication should only represent the total outlet gas flow rate. For some applications, the reactant gas flow rate can be ignored because it is significantly smaller than the main gas flow rate.

[0100] This feedback scheme directly correlates the reactant gas flow rate with the desired output of device 1. Furthermore, the feedback scheme ensures that device 1 continuously meets its outlet requirements by correcting for inaccuracies in the sensing and actuation devices used in the control scheme.

[0101] 3. The flow setpoint is controlled based on feedforward and feedback control using the actual oxygen concentration of the deoxygenated main gas flow.

[0102] exist Figure 6In the described control scheme, a feedforward control scheme and a feedback control scheme are combined by using a feedforward signal as a baseline and correcting for errors in the oxygen concentration in the deoxygenated main gas stream.

[0103] It should be noted that all the alternatives proposed in the control of flow setting based on feedforward control can be used to adjust the desired ratio of reactant gas concentration to oxygen concentration.

[0104] This feedback scheme allows for faster startup and quicker response to load changes because the baseline is directly correlated with the main gas flow. Furthermore, the feedback scheme also directly correlates the reactant gas flow rate with the desired output of device 1, which allows for correction of inaccuracies in the sensing and actuation devices used in the control scheme.

[0105] 4. The flow setpoint is controlled based on feedback control using the actual reactant gas concentration of the deoxygenated main gas stream.

[0106] exist Figure 7 In the described feedback control scheme, the actual concentration of the deoxygenated main gas flow is used to control the reaction gas flow rate.

[0107] A baseline value (variable γ) is used to minimize reactant gas consumption, as this value will be systematically corrected for errors in the oxygen concentration of the deoxygenated main gas stream. γ may depend on the nominal flow rate of unit 1, or may, for example, be equal to the minimum reactant gas flow rate. However, the target outlet reactant gas concentration should be high enough to ensure complete deoxygenation.

[0108] This control scheme is particularly interesting when the reactant gas appears to be detrimental to processes using a deoxygenated main gas stream.

[0109] 5. The flow setpoint is controlled by feedforward and feedback control based on the actual reactant gas concentration using the deoxygenated main gas flow.

[0110] exist Figure 8 In the control scheme described below, a feedforward control scheme and a feedback control scheme are combined by using a feedforward signal as a baseline and correcting for errors in the concentration of the reactant gas in the deoxygenated main gas stream.

[0111] It should be noted that all the alternatives proposed in the control of the flow setpoint based on feedforward control can be used to adjust the desired ratio of reactant gas concentration to oxygen concentration.

[0112] This feedback scheme allows for faster startup and quicker response to load changes because the reactive gas flow rate is directly related to the desired output of device 1.

[0113] This control scheme is particularly interesting when the reactant gas appears to be detrimental to processes using a deoxygenated main gas stream.

[0114] 6. The flow setpoint is controlled based on feedback control using the actual oxygen concentration and actual reactant gas concentration of the deoxygenated main gas stream.

[0115] exist Figure 9 In the described feedback control scheme, the actual oxygen concentration of the deoxygenated main gas flow and the actual reactant gas concentration are used in the control of the reactant gas flow rate.

[0116] The baseline flow rate value γ is thus corrected by the less stringent outlet requirements of device 1.

[0117] 7. The flow setpoint is controlled by feedforward and feedback control based on the actual oxygen concentration and actual reactant gas concentration of the deoxygenated main gas flow.

[0118] exist Figure 10 In this further embodiment, the feedforward scheme is combined with the feedback control scheme using both the actual oxygen concentration of the deoxygenated main gas stream and the actual reactant gas concentration.

[0119] This control scheme is particularly interesting when the reactant gas appears to be detrimental to processes using a deoxygenated main gas stream.

[0120] B. Control of the operation of the reactive gas generator

[0121] According to the following equation, the operation of the reactive gas generator can be determined by the generator setpoint transmitted to the reactive gas generator in each time interval:

[0122] Generator setpoint (t)

[0123] = g(flow setpoint(t), time range) * c p (t)*c e (t)*c c (t)

[0124] Therefore, the generator setpoint is determined by the function g and the pressure coefficient c. p Emission coefficient c e and cost coefficient c c The time-related quantities are calculated by multiplication, and the function g provides a baseline flow target for the reactive gas generator based on the flow setpoint and time range.

[0125] It should be noted that c p (t), c e (t) or c cOne or both of (t) can be equal to 1; in other words, the generator setpoint equation can depend only on the equation selected from c. p (t), c e (t) and c c One or two parameters of the group (t).

[0126] ● The generator setpoint should reflect the desired flow rate to be generated by the reactive gas generator 222. If the desired quantity expected by the reactive gas generator 222 differs from the flow rate, additional calculations should be performed to convert the calculated flow rate into the desired quantity. This desired quantity can be a percentage of the nominal flow rate of the reactive gas generator, or a current equivalent to the flow rate, etc.

[0127] ● The function g depends on the flow setpoint (t) and the time range. The flow setpoint (t) is continuously calculated by the control unit 4 using one of the schemes presented in the previous section. The time range is a time value representing the past period of time that will be viewed.

[0128] Therefore, function g performs algebraic operations on time-dependent flow setpoints over a time range. Several operations are proposed, such as:

[0129] Og(flow setpoint(t), time range) = maximum value(flow setpoint)

[0130] (t-time range, ..., flow setpoint(t)), that is, the maximum consumption in the last time range.

[0131] Og(flow setpoint(t), time range) = average value(flow setpoint)

[0132] (t-time range, ..., flow setpoint(t)), that is, the average consumption over the last time range.

[0133] Og(flow setpoint(t), time range) = flow setpoint′(t)*t, that is, consumption based on the instantaneous time derivative of consumption.

[0134] Og(flow setpoint(t), time range) = flow setpoint(t), i.e., the instantaneous consumption evaluated in each time range.

[0135] ● Pressure coefficient c p It is calculated based on the reactive gas process conditions, more specifically, the reactive gas pressure downstream of the reactive gas generator (e.g., in the reactive gas buffer) at time t. For c p The calculation proposed several options.

[0136] It should be noted that the pressure limit of the reactive gas generator 222 can stop its operation within its own pressure operating range, which is independent of the generator set point and therefore independent of c. p In this situation, these pressure limits become the decisive pressures, and pressure exceeding these limits affects c. p Every adjustment was ineffective.

[0137] The first example of the o operation strategy makes c p It remains constant at a value of α. Therefore, the generator setpoint is set to c. p Scaling. This is in Figure 11 As shown in the diagram.

[0138] o Figure 12 The second example of the operating strategy shown in the figure illustrates the application of pressure parameters defined in control unit 4 to c p Active adjustment. More precisely, a pressure band is introduced, which is controlled by the starting pressure p in control unit 4. 启动 and stopping pressure p 停止 Limited. p 启动 It can be equal to a fixed value, but should be higher than the pressure of the main gas flow at the main gas flow inlet to ensure that the reactant gas is properly injected into the main gas flow. Therefore, p 启动 It can be defined as p 入口主气体 +δ, where δ represents the freely selectable pressure value. p 停止 It can be equal to the maximum pressure at which the reaction gas generator 222 can produce the reaction gas.

[0139] When the reactive gas pressure downstream of the reactive gas generator 222 (in the reactive gas buffer 22) equals the starting pressure, c p =α.

[0140] When the pressure of the reactant gas in the reactant gas buffer 22 reaches the stop pressure, c p =0, and the reaction gas generator 222 stops producing reaction gas until the reaction gas is consumed by the device 1.

[0141] The third example of the o operation strategy introduces the use of running pressure p 运行 The pressure of the reactive gas in the reactive gas buffer 22 is preferably maintained at this operating pressure. 运行 It can be equal to the center of pressure. The pressure band is now around p 运行 Separated by intervals of similar length. Figure 13 The example diagram depicts four intervals.

[0142] This means c p It becomes highly dependent on the pressure of the reacting gas. (The last part, "c"), appears to be incomplete and lacks context. pThe maximum value is set to the selectable variable value β. The number of steps and the width of the steps (pressure range) can also be selected, and are determined via the additional parameter c. p Quantify it.

[0143] Another option is c. p The previous stress-related expression. In this case, the pressure coefficient is expressed as Figure 14 The S-shaped function shown.

[0144] This is how c is expressed. p The benefit is that the pressure is more strongly corrected towards the operating pressure at the edge of the pressure band. This can be more effective in situations where reactant gas demand fluctuates.

[0145] ●Emission factor c e This represents the CO2 emissions at time t associated with the electricity available for the operation of the reactive gas generator 222. If low-carbon electricity is available, this results in an emission factor greater than one, and vice versa.

[0146] The availability of low-carbon electricity can be assessed based on, for example, renewable energy forecasts. This step can be performed, for example, in control unit 4, which can be connected to, for example, a database or information source on the Internet.

[0147] ●The cost coefficient c at time t c This is directly related to the cost of kWh of energy. If low-cost electricity is available, this results in a cost factor greater than one, and vice versa.

[0148] The assessment of electricity costs can be based on actual costs or on expected energy costs and consumption. This step can be performed, for example, in control unit 4, which can be connected to a database or information source, such as the Internet.

[0149] This will achieve one or more of the following objectives.

[0150] 1. By maintaining the pressure of the reactive gas in the reactive gas buffer at p 启动 With p 停止 The operating pressure range between these points reduces the number of start-ups and shutdowns of the reactive gas generator 222, thus increasing its lifespan. This is achieved by adjusting the reactive gas consumption of device 1 (i.e., the flow rate setpoint) and by using c p This is achieved by adjusting the generator setpoint to correct the pressure.

[0151] 2. Reduce operating costs and / or CO2 emissions by generating reactant gases based on the availability of low-cost and low-carbon electricity, respectively;

[0152] 3. The pressure of the reactant gas is more stable, resulting in more accurate injection and ensuring lower design pressure for components due to the selectable operating pressure.

[0153] It should be noted that, in the case of pressure-regulated reactive gas generator 222, c p The value of the function g may be unconstrained because all regulation is achieved through the pressure value of the reactant gas generator 222 rather than the reactant gas flow target. In this case, the emission factor c e and cost coefficient c c It remains in effect.

Claims

1. A device (1) for reducing the oxygen concentration in a main gas stream (1000), characterized in that, The device includes: a. A main gas flow channel (10), the main gas flow channel having a main gas flow inlet (101) for the main gas flow (1000) and a main gas flow outlet (102) for the deoxygenated main gas flow (1000*); b. A reaction gas flow channel (20), the reaction gas flow channel including a reaction gas inlet (201) for a reaction gas flow (2000) at a first end and connected to the main gas flow channel (10) at a connection position (C) at a second end (202) to allow the injection of reaction gas into the main gas flow channel (10), the reaction gas flow channel (20) including a mass flow control device (21) downstream of the reaction gas inlet (201); c. Reactor component (3), which is arranged in the main gas flow channel (10) downstream of the connection position (C) and upstream of the main gas flow outlet (102); d. Control unit (4), the control unit being adapted to control the mass flow control device (21) based on the inlet process conditions of the main gas flow (1000) and / or the outlet process conditions of the deoxygenated main gas flow (1000*) so as to control the injection flow rate of the reaction gas injected into the main gas flow (1000) in the main gas flow channel (10) to the desired reaction gas flow rate.

2. The apparatus for reducing the oxygen concentration in the main gas stream (1000) according to claim 1, characterized in that, The control unit (4) is adapted to calculate the required flow rate of the reactant gas to be injected into the main gas flow (1000) based on the main gas flow (1000) at the main gas inlet (101), the oxygen concentration at the main gas inlet (101), and the required ratio of the reactant gas concentration to the oxygen concentration.

3. The apparatus for reducing the oxygen concentration in the main gas stream (1000) according to claim 2, characterized in that, The required ratio of the reactant gas concentration to the oxygen concentration is constant.

4. The apparatus for reducing the oxygen concentration in the main gas stream (1000) according to claim 2, characterized in that, The desired ratio of reactant gas concentration to oxygen concentration depends on the target oxygen concentration of the deoxygenated main gas stream (1000*).

5. The apparatus for reducing the oxygen concentration in the main gas stream (1000) according to claim 2 or 4, characterized in that, The required ratio of the reactant gas concentration to the oxygen concentration depends on the flow load of the device (1) for reducing the oxygen concentration in the main gas stream (1000).

6. The apparatus for reducing the oxygen concentration in the main gas stream (1000) according to any one of claims 1 to 4, characterized in that, The control unit (4) is adapted to calculate the required flow rate of the reaction gas to be injected into the main gas stream (1000) based on the actual oxygen concentration of the deoxygenated main gas stream (1000*).

7. The apparatus for reducing the oxygen concentration in the main gas stream (1000) according to any one of claims 1 to 4, characterized in that, The control unit (4) is adapted to calculate the required flow rate of the reactant gas to be injected into the main gas stream (1000) based on the actual reactant gas concentration of the deoxygenated main gas stream (1000*).

8. The apparatus for reducing the oxygen concentration in the main gas stream (1000) according to any one of claims 1 to 4, characterized in that, The control unit (4) is adapted to calculate the required flow rate of the reactant gas to be injected into the main gas stream (1000) based on the actual oxygen concentration and the actual reactant gas concentration of the deoxygenated main gas stream (1000*).

9. The apparatus for reducing the oxygen concentration in the main gas stream (1000) according to any one of claims 1 to 4, characterized in that, Controlling the mass flow control device (21) by the control unit (4) includes providing the mass flow control device (21) with a first flow setpoint value for the required flow rate of the reaction gas to be injected, either periodically or continuously.

10. The apparatus for reducing the oxygen concentration in the main gas stream (1000) according to any one of claims 1 to 4, characterized in that, The control unit (4) is also adapted to control the flow rate of the reaction gas entering the reaction gas flow channel (20) from the reaction gas inlet (201).

11. A system (9) for reducing the oxygen concentration in a main gas stream (1000), characterized in that, The system includes a device (1) for reducing the oxygen concentration in the main gas stream (1000) according to any one of claims 1 to 10, and the system further includes a reaction gas generator (222) connected to the reaction gas inlet (201), wherein the control unit (4) is also adapted to control the flow rate of the reaction gas generator (222).

12. The system according to claim 11, characterized in that, The reaction gas generator (222) is fluidly connected to the reaction gas inlet (201).

13. The system according to claim 12, characterized in that, The system also includes a reaction gas buffer (22) disposed downstream of the reaction gas generator (222) and upstream of the reaction gas inlet (201).

14. The system according to any one of claims 11 to 13, characterized in that, Controlling the flow rate of the reaction gas generator (222) includes providing a second flow rate setpoint value for the reaction gas flow (2000) to be generated at least periodically or continuously to the reaction gas generator (222).

15. The system according to claim 14, characterized in that, The system (9) includes a device (1) for reducing the oxygen concentration in the main gas flow (1000) according to claim 9, wherein the second flow setpoint value is a time-dependent function of at least one first flow setpoint or a set of first flow setpoints.

16. The system according to claim 14, characterized in that, The second flow setpoint value is a time-dependent function of the reaction gas pressure measured in the reaction gas flow channel (20) upstream of the mass flow control device (21) or in the reaction gas generator (222).

17. The system according to claim 16, characterized in that, The function includes a polynomial correlation of the reactive gas pressure measured in the reactive gas flow channel (20) upstream of the mass flow control device (21) or in the reactive gas generator (222).

18. The system according to claim 16, characterized in that, The function includes a linear correlation of the reactive gas pressure measured in the reactive gas flow channel (20) upstream of the mass flow control device (21) or in the reactive gas generator (222).

19. The system according to claim 14, characterized in that, The second flow setpoint value is a time-dependent function of the predicted availability of electricity over time.

20. The system according to claim 19, characterized in that, The electricity mentioned is low-carbon emission electricity.

21. The system according to claim 19, characterized in that, The function includes a multinomial correlation of the predicted availability of electricity over time.

22. The system according to claim 19, characterized in that, The function includes a linear correlation of the predicted availability of electricity over time.

23. The system according to claim 14, characterized in that, The second flow setpoint value is a time-dependent function of the predicted cost of energy that varies over time.

24. The system according to claim 23, characterized in that, The function includes a polynomial correlation of the predicted cost of energy that varies over time.

25. The system according to claim 23, characterized in that, The function includes a linear correlation between the predicted cost of energy and its variation over time.

26. The system according to any one of claims 11 to 13, characterized in that, The main gas stream (1000) mainly consists of nitrogen or carbon dioxide.

27. The system according to any one of claims 11 to 13, characterized in that, The reaction gas stream (2000) mainly consists of hydrogen or carbon monoxide.

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