Air supply device for maleic anhydride preparation system including multiple reactors, preparation system using the same, and operation method thereof

Abstract

The present invention provides an air supply device for a maleic anhydride production system including multiple reactors, which includes a feedforward performance controller configured to start a trip emergency control when receiving a trip signal of a reactor and end the trip emergency control after a surge prevention valve is closed. The present invention also provides a maleic anhydride production system including multiple reactors and an operation method thereof. The present invention can supply air to multiple maleic anhydride reactors with a single air compressor.

Description

Technical Field

[0001] The present invention relates to the field of maleic anhydride production, and more specifically, to an air supply device for a maleic anhydride preparation system including multiple reactors, a preparation system using the same, and an operation method thereof. Background Art

[0002] Maleic anhydride is an important basic organic chemical raw material and is widely used in the production of various chemicals. At present, the main industrial production methods of maleic anhydride include the benzene method and the n-butane method. The benzene method uses a mixed gas of benzene and air as raw materials, and oxidizes and converts benzene into maleic anhydride under the action of a catalyst. The n-butane method uses a mixed gas of n-butane and air as raw materials, and oxidizes and converts n-butane into maleic anhydride under the action of a catalyst. In China, the benzene method was mainly used for maleic anhydride production before. However, due to the advantages of the n-butane method in terms of raw materials, environmental protection, efficiency, and cost, the production capacity of maleic anhydride by the n-butane method in China has been increasing in recent years.

[0003] Both the benzene method and the n-butane method use air as one of the raw materials. In a maleic anhydride factory, an air compressor is required to pressurize the air and then supply it to the maleic anhydride reactor for the oxidation reaction.

[0004] Whether in the benzene method or the n-butane method, the most widely used maleic anhydride reactor is an axial tube-sheet fixed bed reactor. The axial tube-sheet fixed bed reactor consists of a large number of tubes and uses molten salt for heat exchange. Since the maleic anhydride formation reaction is a reaction highly sensitive to changes in reaction conditions, the smooth progress of maleic anhydride production and product quality highly depend on the radial uniformity of the materials and temperature in the reactor. However, as the diameter of the reactor increases, the difficulty of controlling the material uniformity and temperature uniformity in the radial direction of the reactor continuously rises. Therefore, in order to ensure the smooth progress of the reaction and the quality of maleic anhydride, the diameter of the maleic anhydride reactor is limited and it is difficult to further expand.

[0005] Since the maximum diameter of a single maleic anhydride reactor is limited, the fluid area through which the fluid passes through the reactor is also limited, which in turn places higher requirements on the bed height of the catalyst. The industrial maleic anhydride reactor has a large aspect ratio of the catalyst bed height to the diameter, and the pressure drop when the reaction fluid flows through the catalyst bed is high, thus requiring a higher outlet pressure of the air compressor. Due to the above-mentioned high sensitivity, the air supply (also called air delivery) of the air compressor needs to be very stable while maintaining high pressure, otherwise it may lead to abnormal reactions or even termination. The above-mentioned air supply requirements pose high requirements on the air supply device for the maleic anhydride reactor.

[0006] In addition, due to the limitation of the maximum diameter of a single maleic anhydride reactor, in a maleic anhydride plant, multiple maleic anhydride reactors usually have to be built to achieve the designed production capacity. In the previous design of maleic anhydride plant projects, in order to ensure the stability of high-pressure air supply, an air compressor is separately equipped for each maleic anhydride reactor for air supply. In such a design, the connection relationship between the air compressor and the maleic anhydride reactor is single, and the operation strategy is simple. The air outlet of the air compressor is directly connected to the air inlet of the maleic anhydride reactor. During production, under normal operating conditions, the air compressor maintains stable air supply, and when encountering sudden abnormal operating conditions, the air compressor can quickly reduce the air supply pressure or completely shut down to avoid accidents.

[0007] With the continuous development of air compressor technology, air compressors with higher air supply pressure and still maintaining air supply stability have emerged. The inventors of the present invention have realized that the air compressor already has the air supply capacity to supply air to two or even more maleic anhydride reactors simultaneously. Therefore, from the perspective of reducing equipment costs, two or even more maleic anhydride reactors can share the same air compressor.

[0008] In order to realize the air supply to multiple maleic anhydride reactors with a single air compressor in actual production, it is necessary to improve the structure and operation method of the air supply device. Summary of the Invention

[0009] In one aspect, the present invention provides an air supply device for a maleic anhydride preparation system including multiple reactors, the air supply device comprising:

[0010] An axial-flow air compressor provided with a stator vane and an anti-surge valve;

[0011] A stator vane controller for feedback control of the stator vane angle based on the target discharge pressure and / or flow rate;

[0012] An anti-surge valve controller for feedback control of the anti-surge valve opening based on the anti-surge line of the air compressor; and

[0013] A feedforward performance controller configured to initiate a trip emergency control when receiving a trip signal of the reactor and end the trip emergency control after the anti-surge valve is closed,

[0014] wherein the trip emergency control includes: feedforward control of the anti-surge valve opening and changing the target discharge pressure and / or flow rate of the stator vane controller.

[0015] Optionally, the trip emergency control further includes feedforward control of the stator vane angle.

[0016] Optionally, the air supply device further comprises:

[0017] An exhaust pressure sensor;

[0018] A throat differential pressure sensor; and

[0019] An optional exhaust gas flow sensor,

[0020] wherein, the stator vane controller performs its feedback control according to the measured value of the exhaust pressure sensor or the exhaust gas flow sensor,

[0021] the surge valve controller performs its feedback control according to the measured values of the exhaust pressure sensor and the throat differential pressure sensor,

[0022] the stator vane controller and the surge valve controller are controllers embedded with a PID algorithm.

[0023] In another aspect, the present invention provides a maleic anhydride preparation system including multiple reactors. The maleic anhydride preparation system including multiple reactors includes:

[0024] Multiple maleic anhydride reactors, and

[0025] The above air supply device, and an outlet pipe of the air compressor of the air supply device is in fluid communication with an inlet pipe of the multiple maleic anhydride reactors, so that the multiple maleic anhydride reactors are connected in parallel downstream of the air compressor.

[0026] In yet another aspect, the present invention provides an operation method according to the above maleic anhydride preparation system including multiple reactors. The operation method includes:

[0027] When the multiple maleic anhydride reactors are operating, the stator vane controller feedback-controls the stator vane angle based on a target exhaust pressure and / or flow rate and according to the measured value, and the surge valve controller feedback-controls the surge valve opening based on the surge line of the air compressor and according to the measured value;

[0028] When at least one of the multiple maleic anhydride reactors trips, after receiving the trip signal of the maleic anhydride reactor, the feedforward performance controller starts the trip emergency control and ends the trip emergency control after the surge valve is closed. Wherein, the trip emergency control includes:

[0029] i) According to the number of remaining operating maleic anhydride reactors, quickly open the surge valve to a first opening degree, and change the target exhaust pressure and / or flow rate of the stator vane controller;

[0030] ii) Reduce the surge valve from the first opening degree, and then wait for the stator vane angle to stabilize;

[0031] iii) Repeat operation ii) until the surge valve is closed.

[0032] Optionally, in operation ii), each time the opening of the anti-surge valve is reduced by 2%-5%.

[0033] Optionally, the operating method includes:

[0034] While quickly opening the anti-surge valve, quickly closing the stationary blade to a first angle.

[0035] In yet another aspect, the present invention provides a use of the above air supply device for a preparation system including multiple reactors, and the feedforward performance controller is configured to initiate a trip emergency control when receiving a trip signal of the reactor. Description of the Drawings

[0036] Figure 1 Shows a typical anti-surge diagram of an air compressor.

[0037] Figure 2 Shows a schematic diagram of the feedforward control connection principle according to an embodiment of the present invention. Specific Embodiments

[0038] With the continuous improvement and development of air compressors in terms of air supply pressure and stability, it has become possible to use a single air compressor to supply air to multiple maleic anhydride reactors simultaneously. However, the inventors have found in practice that it is difficult to achieve the safe production operation of a maleic anhydride preparation system including multiple reactors by directly connecting the exhaust port of the air compressor to the air inlets of two or more parallel maleic anhydride reactors.

[0039] The characteristic of a maleic anhydride reactor is that the stability of the air raw material intake is extremely important for its smooth operation. It can be said that the stability of the air supply volume of the air compressor is a prerequisite for the smooth operation of the maleic anhydride reactor. Therefore, the air compressor used for the maleic anhydride reactor not only needs to provide a sufficiently large pressure and flow rate, but also needs to maintain a stable air supply to each normally operating maleic anhydride reactor as much as possible under various complex working conditions actually faced. Otherwise, it is difficult to truly and successfully implement the design of sharing one air compressor among multiple maleic anhydride reactors.

[0040] When using one air compressor to supply pressurized air to multiple maleic anhydride reactors, the air inlet pipes of each maleic anhydride reactor are directly connected to the exhaust port of the same air compressor, so that multiple maleic anhydride reactors are connected in parallel downstream of the same air compressor. However, the inventor unexpectedly found in practice that it is difficult to meet the actual application requirements by simply making such direct pipe connections downstream of a conventional air compressor. In this connection mode, although stable air supply can be provided to each reactor when all maleic anhydride reactors are operating normally, when some of the multiple maleic anhydride reactors have sudden abnormal conditions, the other maleic anhydride reactors in the system will be adversely affected, and even trip inexplicably. This makes the above device mode not very practical. Without relying on any theory, the inventor found that the reason for these results is the lag of the feedback control of the stator blades and the anti-surge valve, which makes it impossible to stabilize the exhaust pressure and flow rate in a timely manner.

[0041] A sudden abnormal condition of a maleic anhydride reactor is an abnormal shutdown (also known as tripping) caused by some unexpected situations. At this time, to avoid damaging the reactor, the raw material gas pipeline leading to this reactor will be closed as soon as possible to stop receiving air. For multiple independent maleic anhydride reactor design schemes, this will not cause problems, because as the raw material gas pipeline is closed, the air compressor supplying air to the corresponding reactor will also stop or the vent valve will be opened. However, for multiple parallel maleic anhydride reactors sharing the same air compressor, if the air compressor is stopped or vented because one of the reactors trips, the air supply to all maleic anhydride reactors will be stopped, resulting in the reactors that have not tripped also having to stop. This is very uneconomical from the perspective of actual production. Therefore, it is desired that the air compressor can continue to supply air to the remaining reactors when one reactor suddenly trips.

[0042] After a reactor trip, the maleic anhydride reactor will gradually stop receiving air to avoid damaging the reactor. For example, the air inlet flow control valve in the reactor inlet pipe leading to the tripped reactor is closed. One operating mode can be to close the corresponding air inlet flow control valve when the reactor trips and let the air compressor continue to operate to supply air to the remaining reactors. However, through practice, the inventor found that in the maleic anhydride system operating in this way, the air intake of the remaining reactors will be affected, resulting in unstable operation and possible interlock trips. Without relying on any theory, the inventor found the reasons as follows. The total air supply required by the maleic anhydride preparation system is related to the number of reactors in operation. Therefore, when one or several of several maleic anhydride reactors trip suddenly, there will be a large mutation in the requirement for the air supply flow of the air compressor, that is, a large amount of air volume will suddenly decrease in a short period of time. However, the performance adjustment (maintaining the air supply pressure / flow) of a conventional axial flow air compressor is mainly completed by the stator blades, and it cannot quickly and effectively adjust the air supply volume at the outlet of the air compressor when there is a sudden large fluctuation in the subsequent system. Therefore, the operating state of the air compressor cannot be immediately switched to the low air supply volume state required for a smaller number of reactors, but still remains in a relatively high air supply volume state. In this case, when the pressure in the air supply pipe of the air compressor rises sharply due to the incoordination between the high air supply volume state and the low air supply volume demand, it will affect the operating point of the air compressor, and then trigger the response of the anti-surge system of the air compressor. The anti-surge system of the air compressor also takes a long time to complete the adjustment and stabilization of the operating point and cannot quickly stabilize the outlet pressure of the air compressor, thus affecting the air intake of the reactors in operation. In other words, it is difficult for both the conventional feedback-type performance adjustment and the feedback-type anti-surge adjustment to quickly adjust the air supply flow and pressure to the low air supply volume state. Moreover, the anti-surge valve of the air compressor will perform a full-open air release action when the pressure suddenly rises sharply (i.e., a large disturbance), which causes the air supply pressure to drop suddenly. Although the air compressor is protected, the air supply to the maleic anhydride reactor will become insufficient. As mentioned above, the maleic anhydride reactor has high requirements for the stability of air supply. Therefore, if the air compressor does not make relevant adjustments in advance but continues with the feedback-type adjustment, the air supply volume may continue to be too high, too low, or fluctuate violently, all of which will quickly affect the operation of the remaining maleic anhydride reactors, resulting in fluctuations in product quality at worst and reactor shutdown at best, causing an interlock trip and greatly reducing production efficiency.

[0043] Therefore, the method of simply connecting multiple maleic anhydride reactors in parallel downstream of a conventional air compressor cannot properly handle the abnormal reactor trip conditions described above, and it is difficult to implement a practical maleic anhydride preparation system including multiple reactors.

[0044] In view of the above problems, the present invention proposes an air supply device for a maleic anhydride preparation system including multiple reactors, wherein the air supply device includes:

[0045] Axial flow air compressor, which is provided with stator blades and a surge valve;

[0046] Stator blade controller, which feedback-controls the stator blade angle based on the target exhaust pressure and / or flow rate;

[0047] Surge valve controller, which feedback-controls the opening degree of the surge valve based on the surge line of the air compressor; and

[0048] Feedforward performance controller, which is configured to start trip emergency control when receiving a trip signal of the reactor, and end the trip emergency control after the surge valve is closed,

[0049] wherein, the trip emergency control includes: feedforward controlling the opening degree of the surge valve, and changing the target exhaust pressure and / or flow rate of the stator blade controller.

[0050] The air supply device of the present invention includes an axial flow air compressor as its basic component. The axial flow air compressor needs to provide stable air supply for at least two maleic anhydride reactors at the same time. A suitable air compressor can be selected according to the air supply pressure and flow rate required by the maleic anhydride reactor and the number of reactors. In one embodiment, the working pressure of a single maleic anhydride reactor is between 0.29 and 0.35 MPaA, and the required air supply flow rate is between 1000 and 4000 Nm 3 / min.

[0051] The axial flow air compressor is provided with stator blades and a surge valve. These components can all adopt conventional components in the axial flow air compressor.

[0052] The stator blade angle is adjustable, thereby changing the intake air flow rate of the air compressor. The adjustment range of the stator blade angle of a conventional air compressor is between 22° and 79°.

[0053] The surge valve can be arranged on the exhaust pipeline of the air compressor, for example, on a branch pipe branched from the exhaust pipeline of the air compressor, and can be fully opened or opened to a certain degree, so that the exhaust pipeline discharges gas and reduces the air pressure therein. According to the specific adjustment method of the surge valve, there are equal percentage adjustment, linear adjustment, etc. The corresponding opening degree at different flow rates can be obtained by checking the inherent characteristic curve of the surge valve. Usually, it is required that the surge valve can be quickly opened within 1.5 seconds and can be fully opened (from 0% to 100%) within 3 seconds. When the air compressor is running normally, the surge valve is in a closed state.

[0054] The air supply device of the present invention further includes a stator vane controller, which is used to change the stator vane angle. The stator vane controller can be connected to or include a stator vane angle adjustment mechanism. The stator vane controller is a controller with feedback control function, which realizes feedback control based on the difference between the set value and the current value (measured value). For example, the stator vane controller can be a controller adopting proportional integral derivative (PID) control algorithm. This type of controller has a set value (SV) receiving end and a current value (PV) receiving end. The set value of the air compressor exhaust pressure and / or flow rate is input to the controller through the SV receiving end, and the measured value of the air compressor exhaust pressure and / or flow rate is input to the controller through the PV receiving end as the current value. After being calculated by the PID algorithm, a control signal for increasing or decreasing the stator vane angle is sent to the stator vane angle adjustment mechanism through the output (OUT) end. In this way, the stator vane controller can perform feedback control on the stator vane angle based on the deviation between the current value and the set value of the air compressor exhaust pressure and / or flow rate, so as to maintain the exhaust pressure and / or flow rate near the set value. This can ensure stable air supply to the downstream maleic anhydride reactor. It should be noted that the feedback control of the stator vane controller takes effect slowly and does not have sufficient reaction adjustment ability for sudden severe fluctuations in pressure or flow rate.

[0055] The air supply device of the present invention further includes a surge valve controller. The surge valve controller is used to control the surge valve, and it is also a controller with feedback control function. The surge valve feedback control is based on the surge line. By comparing the relative positions of the operating point and the surge line, the opening degree of the surge valve is controlled to adjust the operating point. Similarly, the surge valve controller can also be a controller adopting, for example, the PID algorithm. The SV receiving end of the surge valve controller receives the surge line information, the PV receiving end receives the measurement result of the air compressor operating point, and the OUT outputs the surge valve control signal. When the operating point crosses the surge line and approaches the surge line, based on the measurement result of the operating point, the surge valve is opened at an appropriate angle to reduce the pressure, and the operating point retreats to the normal operating area to prevent the air compressor from surging. It should be noted that the feedback control of the surge valve controller also takes effect relatively slowly and its reaction adjustment ability for sudden severe fluctuations in pressure or flow rate is not very strong.

[0056] The operating point, surge line and surge prevention line are well-known in the field of air compressors. For example, the state point, surge line and surge prevention line can be plotted in a surge prevention diagram with the abscissa being the throat differential pressure of the air compressor and the ordinate being the exhaust pressure of the air compressor. Figure 1A typical anti-surge diagram of an air compressor is shown, in which the surge line 1 and the anti-surge line 2 are shown. In the anti-surge diagram, each point corresponds to a state point representing the throat differential pressure and the discharge pressure of the air compressor. According to the on-site actual surge experiment of the air compressor, the surge points of the air compressor at different stator blade angles can be measured. Connecting these surge points gives the actual surge line of the air compressor. For the state points in the area below and to the right of this surge line (where the throat differential pressure is greater and the discharge pressure is lower), the air compressor does not surge. Above the surge line and to its upper left (where the throat differential pressure is too small and the discharge pressure is too high), the air compressor will surge. Furthermore, a certain safety margin (e.g., 10%) is reserved below and to the right of the surge line as the anti-surge line. When the increase in the discharge pressure of the air compressor causes the operating point to cross the anti-surge line, the air compressor can open the anti-surge valve by a certain opening to reduce the discharge pressure, so that the operating point moves away from the surge line and avoids surging. As the operating conditions causing surging gradually change, the anti-surge valve gradually closes. This process can be achieved by the anti-surge valve controller through feedback control. In one embodiment, after the throat differential pressure undergoes temperature and pressure compensation operations and is calculated according to a piecewise function within the control system, it serves as the set value SV of the anti-surge valve controller, and the measured value of the discharge pressure of the air compressor serves as the current value PV of the anti-surge valve controller. The required opening of the anti-surge valve is calculated (e.g., using the PID algorithm), and the opening of the anti-surge valve is controlled accordingly to avoid surging. It can be understood that in addition to the PID algorithm, other suitable feedback algorithms can also be used.

[0057] The feedback control of the anti-surge valve is applicable to the situation where the disturbance is small, that is, the operating point slowly and slightly crosses the anti-surge line. In this case, the operating point can be adjusted by gradually opening the anti-surge valve. However, when the pressure rises rapidly and significantly, or in other words, when the disturbance is large, the operating point may quickly pass through the safety margin area between the anti-surge line and the surge line and reach the surge area. The lag of the above-mentioned feedback control will make it difficult to ensure avoiding surging. Therefore, in the case where large disturbances cause the operating point to possibly or already enter the surge area, in order to simply protect the air compressor, a conventional air compressor takes the operation of immediately opening the anti-surge valve to its maximum (i.e., fully open) to release air, so as to quickly reduce the discharge pressure and make the operating point leave the surge area and eliminate the surging phenomenon. As described above, the inventors found that this seriously affects the stability of the air supply to the remaining maleic anhydride reactors, and in severe cases, the reactor will trip due to too low air supply flow rate.

[0058] The present invention sets a feedforward performance controller in the air supply device and appropriately disposes of the tripping condition of the reactor. More specifically, the present invention uses the feedforward performance controller in the case of reactor tripping to cooperate and adjust the anti-surge valve and the stator blades to control the discharge pressure and flow rate of the air compressor.

[0059] The feedforward performance controller is configured to initiate a trip emergency control when receiving a trip signal of the maleic anhydride reactor, and end the trip emergency control after the anti-surge valve is closed. The trip emergency control includes: feedforward controlling the opening of the anti-surge valve, and changing the target exhaust pressure and / or flow rate of the static vane controller.

[0060] In other words, in view of the situation that some maleic anhydride reactors in the maleic anhydride preparation system with multiple reactors may suddenly trip, the present invention specifically provides a feedforward performance controller in the air supply device for emergency handling of trips.

[0061] The feedforward performance controller does not work when there is no trip in the multiple reactors of the maleic anhydride preparation system. When each reactor is operating normally, the exhaust pressure of the air compressor is feedback-controlled by the static vane controller and the anti-surge valve controller. This feedforward performance controller only participates in the control of the air supply device when an abnormal condition of a trip occurs. Even if the exhaust pressure of the air compressor suddenly rises for other reasons, this feedforward performance controller does not work.

[0062] Figure 2 The schematic diagram of the feedforward control connection principle according to an embodiment of the present invention is shown.

[0063] As shown in the figure, when there is no trip in the reactor, the static vane controller feedback-controls the static vane angle through the output terminal OUT according to the set value at the SV1 terminal and the measured value or actual value at the PV terminal, and when the operating point of the air compressor crosses the anti-surge line, the anti-surge valve controller feedback-controls the opening of the anti-surge valve through the output terminal OUT according to the anti-surge line input from SV1 and the actual operating point position output from PV to eliminate possible surge phenomena.

[0064] The maleic anhydride preparation system can generate and send a trip signal when the maleic anhydride reactor trips. The maleic anhydride preparation system can send various reactor operating state signals or simply referred to as operating state signals, and the trip signal is one of them. The signal type of the operating state signal can be a digital dry contact signal. The operating state signal can be automatically generated by the control system of the reactor (such as a distributed control system, DCS). The control system of the reactor measures the parameters of the reactor to judge whether the reactor is operating normally. If the control system judges that the reactor is operating normally, it outputs a dry contact signal indicating normal operation as the normal operating state signal, which can be a closed signal for example. When the reactor trips due to factors such as a fault, it outputs a trip operating state signal, which can be an open signal for example. It can also be that the system operator actively issues a trip signal when discovering a trip occurs.

[0065] The feedforward performance controller is configured to be able to receive the trip signal of the maleic anhydride reactor, and initiate a trip emergency control in response to the trip signal. As Figure 2As shown, the feedforward performance controller can receive the trip signals of Reactors 1, 2, and 3. The emergency control of the present invention coordinates and controls the anti-surge valve and the compressor stator blades in advance according to the air volume loss after the reactor trips, ensuring the stability of the air supply to the remaining non-tripped reactors while preventing the compressor from surging. As Figure 2 shown, the feedforward performance controller conducts operation control through output terminals OUT1 and OUT2.

[0066] The emergency control includes feedforward control of the opening degree of the anti-surge valve. As described above, when feedback-controlled by the anti-surge valve controller, the anti-surge valve gradually opens under small disturbances based on the increased exhaust pressure measurement value and fully opens for exhaust under large disturbances. In contrast, the feedforward performance controller of the present invention is activated in response to the trip signal and controls the anti-surge valve in advance. That is, instead of performing feedback control after the pressure increases due to the trip and subsequent closing of the inlet flow regulating valve of the reactor, the feedforward performance controller controls according to the air supply requirement after the trip in advance. From the trip signal, the number of tripped reactors can be known, so the reduced air supply volume required for the corresponding working condition and the air supply volume required for the remaining reactors to continue operating can be known in advance. For example, in a three-reactor system, when the feedforward performance controller receives one trip signal, it can be known that one reactor has tripped and the other two reactors are still operating. The feedforward performance controller can calculate an appropriate opening degree of the anti-surge valve according to the required air supply volume and the performance curve of the anti-surge valve. The feedforward performance controller directly opens (or quickly opens) the anti-surge valve to this opening degree. At this opening degree of the anti-surge valve, the exhaust from the anti-surge valve is not gradually opened by feedback or fully opened for exhaust, but quickly opened under control. By exhausting through the anti-surge valve, the gas flow is adapted to the requirement of the remaining maleic anhydride reactors, so that the air flow flowing to the remaining reactors hardly fluctuates. During this process, the operating point of the air compressor does not reach the surge line and no surging occurs.

[0067] The feedforward performance controller can control the opening degree of the anti-surge valve through the anti-surge valve controller. That is, the feedforward performance controller sends a control signal to the anti-surge valve controller, and then controls the anti-surge valve through the signal output from the OUT terminal of the anti-surge valve controller. As Figure 2 shown, the anti-surge valve controller normally feedback-controls the opening degree of the anti-surge valve according to the anti-surge line received from the SV1 terminal and the working point position received from the PV terminal, but receives the feedforward signal output from the OUT1 output terminal of the feedforward performance controller from the SELSV2 terminal when the feedforward performance controller takes effect.

[0068] At the same time, the feedforward performance controller also calculates the required exhaust pressure and flow rate that the air compressor needs to provide at this opening degree of the anti-surge valve according to the known required air supply volume, and sends these required values as the target exhaust pressure and / or flow rate to the stator blade controller. AsFigure 2 As shown, it is output from the OUT2 output terminal of the feedforward performance controller to the SEL SV2 terminal of the stator vane controller. The stator vane controller obtains the changed target exhaust pressure and / or flow rate from the feedforward performance controller, replacing the set value previously received from the SV1 terminal. The changed target exhaust pressure and / or flow rate are applicable to the operation of the remaining reactors under the aforementioned anti-surge valve opening. Based on the changed target exhaust pressure and / or flow rate, the stator vane controller still feedback-controls the stator vane angle based on the measured value received from the PV terminal, so that the actual exhaust pressure and / or flow rate remain basically stable.

[0069] Through the feedforward control of the anti-surge valve opening by the feedforward controller and the coordinated feedback control of the stator vane angle, stable exhaust pressure and flow rate are obtained, ensuring that the remaining reactors can still operate normally.

[0070] However, considering the stability of the normal operation of the system, the anti-surge valve cannot be kept open for a long time, and this state also causes a large amount of unnecessary compressed air to be discharged from the anti-surge valve, wasting energy. Therefore, the feedforward performance controller continues to work and gradually closes the anti-surge valve in small steps in a feedforward manner. For example, in one embodiment, the opening is first reduced by a certain degree, such as 2% - 5%. When the opening of the anti-surge valve is reduced in small steps, the exhaust pressure and flow rate change slightly correspondingly, but not drastically. However, since the stator vane controller is still performing feedback control, the exhaust pressure and flow rate of the air compressor are coordinated and stabilized through the change of the stator vane angle.

[0071] After the exhaust pressure is stabilized, that is, after the stator vane angle remains basically unchanged, the feedforward performance controller continues to reduce the opening and repeats the above operation. By gradually and slowly reducing the opening of the anti-surge valve in this way, the surge valve will eventually be completely closed. During this process, a stable air supply to the remaining maleic anhydride reactors can always be maintained, enabling them to operate normally.

[0072] When the surge valve is completely closed, the multi-reactor maleic anhydride preparation system has safely escaped from the sudden shutdown situation and reached a new steady-state operation state compared with before, in which the number of operating reactors has decreased, and the target exhaust pressure and / or flow rate have changed accordingly. At this time, the stator vane angle decreases, resulting in a decrease in the intake air flow rate and a decrease in the throat differential pressure, and the air compressor will operate at a new operating point. Correspondingly, the feedforward performance control for sudden shutdown emergency control ends.

[0073] As described above, in one embodiment, in order to receive signals from the feedforward performance controller, the static vane controller may have another setpoint receiver. The original setpoint receiver is SV1, and the new setpoint receiver is SEL SV2. SEL SV2 is connected to a signal output terminal OUT2 of the feedforward performance controller. When the SEL SV2 receiver receives the changed target exhaust pressure and / or flow rate from the feedforward performance controller, the target exhaust pressure and / or flow rate input value of the original SV1 becomes invalid.

[0074] As described above, in one embodiment, the anti-surge valve controller may also have another setpoint receiver SEL SV2 and is connected to another signal output terminal OUT1 of the feedforward performance controller. When the SEL SV2 receiver of the anti-surge valve controller receives a control signal from the feedforward performance controller, it will directly change the opening of the anti-surge valve through the OUT terminal. The advantage of the feedforward performance controller controlling the anti-surge valve through the anti-surge valve controller is that all control signals for the anti-surge valve are issued by the anti-surge valve controller, avoiding control conflicts. When the feedforward performance controller performs emergency control, the feedback control of the anti-surge valve controller is temporarily invalid because the feedforward performance controller can already ensure that surging does not occur.

[0075] The feedforward performance controller takes receiving the trip signal of the maleic anhydride reactor as a prerequisite for starting the trip emergency control and determines the corresponding feedforward control strategy. According to the number of reactor trip signals received, the number of remaining reactors still in operation can be known, and the required air supply volume for them to maintain normal operation can be obtained accordingly. For example, for a three-reactor system, if one trip signal is received, it means that two reactors still need to remain in operation. For the number of trip signals, the feedforward performance controller can give the required control strategy and corresponding control signals.

[0076] Continuing with the example of one reactor trip in a three-reactor system for illustration. When one reactor trips, it immediately sends a trip signal to the feedforward performance controller. The feedforward performance controller then determines that the maleic anhydride system should subsequently operate in a two-reactor mode. The feedforward performance controller calculates the required air supply volume for the two-reactor operation. Based on the inherent characteristic curve of the anti-surge valve, according to this air supply volume, the feedforward performance controller sends an opening control signal to the anti-surge valve controller, causing the anti-surge valve to quickly open to the predetermined opening.

[0077] The principle for selecting the predetermined opening of the anti-surge valve is, first, to ensure that the exhaust pressure is in the non-surge zone in the surge prevention diagram under the current throat differential pressure, preferably in the safe zone below the right of the surge prevention line; second, to make the air flow rate and pressure flowing to the non-tripped maleic anhydride reactor basically unchanged at this opening, for example, the fluctuation does not exceed 20%, more preferably 10%, more preferably 5%, more preferably 2%.

[0078] The ultimate goal of the emergency control is to achieve the air supply pressure and flow rate required during the operation of the two reactors. To this end, the feed-forward performance controller inputs the target exhaust pressure and / or flow rate into the stator vane controller, replacing its original exhaust pressure / flow rate set value. In other words, after the feed-forward performance controller starts the emergency control, the exhaust pressure and / or flow rate set value of the stator vane controller changes to a value suitable for the two reactors. Subsequently, based on this new set value, the stator vane controller stabilizes the air supply pressure and flow rate by adjusting the stator vane, thereby ensuring the basic stable operation of the remaining reactor.

[0079] At this time, the surge prevention valve is still in the state of opening a predetermined opening degree, and it is necessary to gradually close it to return to the normal operation state so as to continue to play the role of surge prevention. To this end, the performance controller continues to send a feed-forward control signal to the surge prevention valve controller. This control signal causes the surge prevention valve to close gradually. In a preferred embodiment, the control signal can be such that the opening degree of the surge prevention valve is reduced by 2%-5% at a time. After the opening degree is reduced, the feedback control of the stator vane controller makes the exhaust pressure and flow rate stable again by adjusting the stator vane. The opening degree reduction step range of 2%-5% can achieve a good balance between closing the surge prevention valve as soon as possible and waiting for the stator vane to adjust in time. After the stator vane is stable, the next reduction of the opening degree of the surge prevention valve is carried out. Repeat this process until the surge prevention valve is completely closed. At this time, the feed-forward performance controller ends the emergency control.

[0080] Thus, starting from receiving the reactor trip signal, the feed-forward performance controller coordinates the control of the surge prevention valve and the stator vane, adjusts the air intake and air release of the air compressor in advance, and adjusts the outlet pressure and flow rate (i.e., the surge prevention valve - performance control is put into operation) to obtain the required air supply. Since it is a feed-forward control in response to the trip signal, it is different from the feedback control. It can effectively intervene in the air supply device before the change of the air compressor rear system pipeline network has a greater impact on the adjustment of the air compressor. During this process, it neither damages the air compressor nor affects the operation of the remaining reactor. Through the control of the feed-forward performance controller, the fluctuations caused by the reactor trip are effectively controlled under the collaborative adjustment of the stator vane and the surge prevention valve, reducing the risk and probability of the device interlocking and shutting down.

[0081] The air supply device of the present invention combines the surge prevention control adjustment of the air compressor, the stator vane control adjustment, and the operation state signal of the maleic anhydride reactor, and jointly forms a new air compressor air supply adjustment system with the added feed-forward performance controller, thereby ensuring the stability of the air supply to the remaining reactor.

[0082] In one embodiment, the trip emergency control further includes feed-forward controlling the stator vane angle.

[0083] To complete the emergency control of tripping more quickly, the static blade angle can also be rapidly reduced by an angle while quickly opening the anti-surge valve. Compared with simply performing feedback control on the static blade angle, reducing the static blade angle feedforwardly can result in a smaller initial opening of the anti-surge valve, so that the subsequent emergency control of tripping can be completed more rapidly.

[0084] Preferably, the air supply device further comprises:

[0085] An exhaust pressure sensor;

[0086] A throat differential pressure sensor; and

[0087] An optional exhaust gas flow sensor,

[0088] wherein, the static blade controller performs its feedback control according to the measured value of the exhaust pressure sensor or the exhaust gas flow sensor,

[0089] the anti-surge valve controller performs its feedback control according to the measured values of the exhaust pressure sensor and the throat differential pressure sensor,

[0090] the static blade controller and the anti-surge valve controller are controllers embedded with the PID algorithm.

[0091] In one embodiment, the air supply device of the present invention comprises an exhaust pressure sensor. The exhaust pressure sensor can be connected to the anti-surge valve controller to provide the anti-surge valve controller with the measured exhaust pressure value as a feedback value. The exhaust pressure sensor can be connected to the PV input terminal of the anti-surge valve controller with the PID algorithm. The exhaust pressure sensor can also be connected to the static blade controller to provide the static blade controller with the measured exhaust pressure value as a feedback value. The exhaust pressure sensor can be connected to the PV input terminal of the static blade controller with the PID algorithm.

[0092] In one embodiment, the air supply device of the present invention comprises a throat differential pressure sensor. The throat differential pressure sensor can be connected to the anti-surge valve controller to provide the anti-surge valve controller with the measured throat differential pressure value as a set value. The throat differential pressure sensor can be connected to the PV input terminal of the anti-surge valve controller with the PID algorithm.

[0093] In one embodiment, the air supply device of the present invention comprises an exhaust gas flow sensor. The exhaust gas flow sensor can be connected to the static blade controller to provide the static blade controller with the measured exhaust gas flow value as a feedback value. The exhaust gas flow sensor can be connected to the PV input terminal of the static blade controller with the PID algorithm.

[0094] By monitoring parameters such as the exhaust pressure, the throat differential pressure, and the exhaust gas flow, the static blade controller and the anti-surge valve controller can achieve feedback control.

[0095] The air supply device of the present invention may further include other parameter measuring instruments, such as a thermometer, etc. The measurement of other parameters such as temperature may also participate in the feedback control of the anti-surge valve or the stator blades.

[0096] The air supply device for a maleic anhydride production system including multiple reactors according to the present invention can realize a practical maleic anhydride production system.

[0097] In one embodiment, the present invention provides a maleic anhydride production system including multiple reactors, wherein the maleic anhydride production system including multiple reactors includes:

[0098] Multiple maleic anhydride reactors, and

[0099] The above-mentioned air supply device, the outlet pipeline of the air compressor of the air supply device is in fluid communication with the reactor inlet pipelines of the multiple maleic anhydride reactors, so that the multiple maleic anhydride reactors are connected in parallel downstream of the air compressor.

[0100] As described above, such a maleic anhydride production system can realize driving multiple maleic anhydride reactors by one air compressor and can appropriately cope with abnormal conditions such as reactor trip.

[0101] The inventor of the present invention proposed a related operation method while inventing a maleic anhydride production system including multiple reactors, which can appropriately cope with the reactor trip condition when one air compressor drives multiple maleic anhydride reactors.

[0102] The maleic anhydride production system including multiple reactors according to the present invention includes a feedforward performance controller, which can realize trip emergency control.

[0103] In one embodiment, the present invention proposes an operation method for the above-mentioned maleic anhydride production system including multiple reactors, wherein the operation method includes:

[0104] When the multiple maleic anhydride reactors are operating, the stator blade controller feedback-controls the stator blade angle based on the target exhaust pressure and / or flow rate and according to the measured value, and the anti-surge valve controller feedback-controls the anti-surge valve opening based on the anti-surge line of the air compressor and according to the measured value;

[0105] When at least one of the multiple maleic anhydride reactors trips, after the feedforward performance controller receives the trip signal of the maleic anhydride reactor, it starts the trip emergency control and ends the trip emergency control after the anti-surge valve is closed, wherein the trip emergency control includes:

[0106] i) According to the number of remaining operating maleic anhydride reactors, quickly open the anti-surge valve to a first opening degree, and change the target exhaust pressure and / or flow rate of the stator blade controller;

[0107] ii) Reduce the anti-surge valve from the first opening degree, and then wait for the stator blade angle to stabilize;

[0108] iii) Repeat operation ii) until the anti-surge valve is closed.

[0109] As described above, in operation i), the first opening degree of the rapid opening of the anti-surge valve in the tripping emergency control is calculated according to the number of remaining operating maleic anhydride reactors. According to the required air supply volume and the performance curve of the anti-surge valve, the appropriate first opening degree of the anti-surge valve is calculated. At this opening degree of the anti-surge valve, the air release from the anti-surge valve is not gradually opened, nor fully opened for air release, but is rapidly opened under control. By releasing air through the anti-surge valve, the gas flow rate is adapted to the requirements of the remaining maleic anhydride reactors, so that the air flow rate flowing to the remaining reactors basically does not fluctuate.

[0110] At the same time, the tripping emergency control also calculates the required target exhaust pressure and / or flow rate according to the number of remaining operating maleic anhydride reactors, and correspondingly changes the target exhaust pressure and / or flow rate of the stator blade controller.

[0111] Based on this, operations ii) and iii) are carried out, and the opening degree of the anti-surge valve can be gradually reduced in a feed-forward manner until it is closed, and the stator blade controller can always stabilize the exhaust pressure and flow rate at the level required by the remaining operating maleic anhydride reactors through feedback control. Thus, the basic stability of the air supply after the reactor trips is achieved, enabling the remaining reactors to operate and avoiding interlock tripping.

[0112] Preferably, in operation ii), the anti-surge valve is reduced by 2%-5% from the first opening degree. As described above, this can achieve a good balance between closing the anti-surge valve as soon as possible and waiting for the stator blade to be adjusted in time.

[0113] In one embodiment, in operation i), while the anti-surge valve is rapidly opened, the stator blade is rapidly closed to the first angle. Appropriate initial first opening degree and first angle can be set for different numbers of tripping reactors, and the two cooperate to ensure the stability of the air supply pressure and flow rate. Such efficiency is higher than only controlling the stator blade angle in a feedback manner.

[0114] Although the present invention is made based on the air supply device of a maleic anhydride preparation system including multiple reactors, the inventor finds that the air supply device of the present invention can also be used in other reaction systems with the same characteristics as maleic anhydride preparation. That is, each reactor needs to be supplied with air, but the scale of each reactor is limited, so a single air compressor can be used to supply air to multiple reactors. At the same time, the reactor is sensitive to fluctuations in the gas supply flow rate and pressure, and may interlock and stop due to the tripping of one reactor. For such reaction systems, the air supply device of the present invention can also be used.

[0115] In one embodiment, the present invention provides the use of the air supply device of the present invention in a preparation system comprising multiple reactors, wherein the feedforward performance controller is configured to initiate a trip emergency control when receiving a trip signal of the reactor.

[0116] At this time, it is only necessary to change the initiation of the feedforward performance controller to be triggered by the corresponding reactor trip signal. This expands the application scope of the air supply device of the present invention.

[0117] The present invention will be described in more detail below through examples.

[0118] Example 1:

[0119] Production is carried out using a maleic anhydride preparation system in which one air compressor supplies air to three parallel maleic anhydride reactors simultaneously. The three maleic anhydride reactors are respectively called Reactor No. 1, Reactor No. 2, and Reactor No. 3. The reaction raw material is n-butane.

[0120] A stator vane controller is set, with a PID algorithm embedded. Its output terminal OUT is connected to the stator vane adjusting mechanism to control the stator vane angle. Its first set value receiving terminal SV1 obtains the target exhaust pressure set value when the reactor is operating normally from the control system. Its current value receiving terminal PV receives the real-time exhaust pressure measurement value from the exhaust pressure sensor.

[0121] A surge controller is set, with a PID algorithm embedded. Its output terminal OUT is connected to the surge valve to control the opening of the surge valve. Its first set value receiving terminal SV1 obtains the surge map from the control system, including the surge line and the anti-surge line. Its current value receiving terminal PV receives the real-time operating point parameters from the exhaust pressure sensor and the throat differential pressure sensor.

[0122] A feedforward performance controller is set. The three signal input terminals of the feedforward performance controller receive the operating signals from Reactor Nos. 1-3. Its second output terminal OUT1 is connected to the second set value receiving terminal SEL SV2 of the surge controller. Its first output terminal OUT2 is connected to the second set value receiving terminal SEL SV2 of the stator vane controller.

[0123] As Figure 2 shown, the reactor, the surge controller, the surge valve, the stator vane controller, the stator vane, and the feedforward performance controller are connected together.

[0124] First, make Reactor Nos. 1-3 operate in a normal state. At this time, the feedforward performance controller does not work. The stator vane controller performs feedback control on the stator vane angle based on the target exhaust pressure set value obtained by SV1 and the measurement value obtained by PV. The surge controller performs feedback control on the opening of the surge valve based on the anti-surge line obtained by SV1 and the operating point parameters obtained by PV.

[0125] To simulate the tripping of the reactor, the No. 1 reactor was shut down, and immediately the air inlet flow regulating valve leading to the No. 1 reactor was closed, and at the same time a tripping signal was sent to the feedforward performance controller.

[0126] The tripping signal of the No. 1 reactor caused the feedforward performance controller to start and begin the tripping emergency control. According to the fact that there was 1 tripping signal, it was expected that the air supply flow would become two-thirds of the original, and the pressure remained unchanged. For this reason, the feedforward performance controller sent a feedforward signal to SEL SV2 of the anti-surge valve, quickly opening the opening of the anti-surge valve to the first opening (not fully open) to discharge the gas. At this first opening, at the current static blade angle and the operating state of the air compressor, the exhaust flow of the air leading to the downstream was two-thirds of the previous value, and the pressure remained unchanged. This operating point was below the right of the anti-surge line, and surge could be avoided.

[0127] At the same time, the feedforward performance controller sent this target exhaust pressure and / or flow to SELS V2 of the static blade controller. The static blade controller then carried out feedback control based on the changed target exhaust pressure and / or flow. Since the flow and pressure were approximately the target values at this time, the static blade controller only fine-tuned the static blade angle according to the feedback of the measured values.

[0128] Subsequently, the feedforward performance controller reduced the opening of the anti-surge valve by 2%. At this time, both the exhaust pressure and flow increased. The static blade controller would receive the increased pressure / flow measured values and carry out feedback control on the static blade, reducing the static blade angle so that the exhaust pressure and flow decreased back to the target values.

[0129] After the exhaust pressure and flow were stable around the target values (that is, after the static blade angle no longer continued to decrease), the feedforward performance controller reduced the opening of the anti-surge valve by 2% again. Repeat the above process until the anti-surge valve is fully closed.

[0130] After the anti-surge valve was fully closed, the feedforward performance controller was turned off, ending the tripping emergency control. The anti-surge valve controller took over the feedback control of the anti-surge valve.

[0131] During this process, the air inlet pressure and flow in the No. 2 and No. 3 reactors were monitored, and the working state of the reactors was checked. It was found that the fluctuations of the air inlet pressure and flow in the No. 2 and No. 3 reactors were not large, the reactors operated stably, the product output and quality were stable, and were not affected by the tripping of the No. 1 reactor.

[0132] Example 2

[0133] The test was carried out in the same manner as in Example 1, except that the No. 1 and No. 2 reactors in the three reactors were simulated to trip.

[0134] Accordingly, the feedforward performance controller quickly opens the anti-surge valve, and the changed target exhaust gas flow rate sent to the stator blade controller is one-third of the previous value, with the pressure remaining unchanged. Due to the larger opening, during the feedforward control, the reduction in the opening of the anti-surge valve each time is increased to 5%.

[0135] During this process, the air intake pressure and flow rate in Reactor 3 are monitored, and the operating state of the reactor is checked. It is found that the fluctuations in the air intake pressure and flow rate of Reactor 3 are not significant. The reactor operates stably, and the product output and quality are stable, without being affected by the tripping of Reactors 1 and 2.

[0136] Comparative Example 1:

[0137] Except for not setting the feedforward controller, air is supplied to the maleic anhydride reactor with the same device as in Example 1.

[0138] After simulating the tripping of Reactor 1, the measured exhaust pressure rises quickly and triggers the feedback control of the anti-surge controller, and the anti-surge valve opens fully. Soon after the anti-surge valve opens fully, Reactors 2 and 3 trip and stop operating due to insufficient air supply.

[0139] Comparative Example 2:

[0140] Except for not setting the feedforward controller, air is supplied to the maleic anhydride reactor with the same device as in Example 2.

[0141] After simulating the tripping of Reactors 1 and 2, the measured exhaust pressure rises quickly and triggers the feedback control of the anti-surge controller, and the anti-surge valve opens fully. After the anti-surge valve opens fully, Reactor 3 quickly trips and stops operating due to insufficient air supply.

[0142] It can be seen from this that the device and method of the present invention, when one or several of multiple maleic anhydride reactors suddenly shut down, while ensuring that the air compressor will not be damaged due to surge, also ensure that the remaining reactors will not cause abnormal operation or interlock shutdown due to a sudden reduction in air supply.

[0143] In addition, the above experiments were also conducted on the benzene process system for producing maleic anhydride, and similar experimental results were obtained.

[0144] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claimed rights.

Claims

1. An air supply device for a maleic anhydride preparation system comprising multiple reactors, characterized in that, The air supply device includes: An axial flow air compressor provided with stator vanes and an anti-surge valve; A stator vane controller that feedback-controls the stator vane angle based on the target exhaust pressure and / or flow rate; An anti-surge valve controller that feedback-controls the opening of the anti-surge valve based on the anti-surge line of the air compressor; and A feedforward performance controller configured to initiate a trip emergency control when receiving a trip signal of the reactor and end the trip emergency control after the anti-surge valve is closed, wherein the trip emergency control includes: feedforward controlling the opening of the anti-surge valve and changing the target exhaust pressure and / or flow rate of the stator vane controller.

2. The air supply device according to claim 1, wherein The trip emergency control further includes feedforward controlling the stator vane angle.

3. The air supply device according to claim 1, characterized in that, The air supply device further includes: An exhaust pressure sensor; A throat differential pressure sensor; and An optional exhaust flow sensor, wherein the stator vane controller performs its feedback control according to the measured value of the exhaust pressure sensor or the exhaust flow sensor, the anti-surge valve controller performs its feedback control according to the measured values of the exhaust pressure sensor and the throat differential pressure sensor, the stator vane controller and the anti-surge valve controller are controllers embedded with a PID algorithm.

4. A maleic anhydride preparation system comprising multiple reactors, characterized in that, The maleic anhydride preparation system including multiple reactors includes: Multiple maleic anhydride reactors, and The air supply device according to any one of claims 1-3, the outlet pipe of the air compressor of the air supply device is in fluid communication with the reactor inlet pipes of the multiple maleic anhydride reactors, such that the multiple maleic anhydride reactors are connected in parallel downstream of the air compressor.

5. A method for operating a maleic anhydride preparation system comprising multiple reactors according to claim 4, characterized in that, The operation method includes: When the multiple maleic anhydride reactors are operating, the stator vane controller feedback-controls the stator vane angle based on the target exhaust pressure and / or flow rate and according to the measured value, and the anti-surge valve controller feedback-controls the opening of the anti-surge valve based on the anti-surge line of the air compressor and according to the measured value; When at least one of the multiple maleic anhydride reactors trips, the feedforward performance controller initiates the trip emergency control after receiving the trip signal of the maleic anhydride reactor and ends the trip emergency control after the anti-surge valve is closed, wherein the trip emergency control includes: i) According to the number of remaining operating maleic anhydride reactors, quickly open the anti-surge valve to a first opening and change the target exhaust pressure and / or flow rate of the stator vane controller; ii) Reduce the opening of the anti-surge valve from the first opening, and then wait for the stator vane angle to stabilize; iii) Repeat operation ii) until the anti-surge valve is closed.

6. The operating method according to claim 5, characterized in that In operation ii), each time the opening of the anti-surge valve is reduced by 2%-5%.

7. The operating method according to claim 5, characterized in that, The operation method includes: Quickly closing the stator vane to a first angle while quickly opening the anti-surge valve.

8. Use of the air supply device according to any one of claims 1-3 in a preparation system including multiple reactors, characterized in that The feedforward performance controller is configured to initiate a trip emergency control when receiving the trip signal of the reactor.

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