Modular ammonia synthesis reactor with adjustable capacity and control method thereof

Abstract

The present application relates to a kind of modular ammonia synthesis reactor of adjustable capacity and its control method, including multiple single reactors;The import of the single reactor is mutually connected after being parallelly connected, and is connected with feed pipe after being communicated through heating device, and its export is mutually connected after being parallelly connected, and is connected with discharge pipe;The heating device is electrically connected with control system;The import of the single reactor and export are equipped with control valve respectively;The control valve is electrically connected with the control system, so that each single reactor can be controlled to work independently or combined work.The present application realizes the capacity regulation in a large range by combining multiple single reactors into modular assembly, meets the production demand in different stages.Moreover, it can also run without opening electric furnace under low load, reduces energy consumption and environmental pollution, realizes green production.Therefore, the standardization and serialization of equipment are realized, which is conducive to large-scale production and application promotion.

Description

TECHNICAL FIELD

[0001] The present application relates to a chemical production device and method, in particular to an ammonia synthesis reactor and a control method thereof, and more particularly to a modular ammonia synthesis reactor with adjustable production capacity and a control method thereof. BACKGROUND

[0002] The ammonia synthesis reactor is the core equipment in the ammonia synthesis process. The traditional ammonia synthesis reactor is mainly a fixed capacity reactor designed according to the maximum running production capacity of the device, which belongs to a fixed bed reactor. This type of ammonia synthesis reactor is suitable for running at a load of 70%-105% of its design capacity. When it is running at a low load, the heat generated by the synthesis reaction is not enough to maintain the temperature inside the reactor, and an electric heater must be started to supplement the heat, resulting in increased energy consumption, which is not conducive to energy saving and environmental protection. At present, the number of green ammonia devices is increasing, and the operating load of green ammonia devices fluctuates greatly (some owners require 10%-110%). Due to the characteristics of green electricity, most green ammonia devices are running at ultra-low load at night, which makes the traditional ammonia synthesis reactor unable to meet the production under economic conditions.

[0003] Therefore, it is urgent to develop a new type of ammonia synthesis reactor with adjustable production capacity. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a modular ammonia synthesis reactor with adjustable production capacity and a control method thereof, which can flexibly adjust the production capacity load in a larger range, fully meet the demand of large fluctuation of green ammonia device operating load, and is easy to install and maintain, low in energy consumption, high in operation flexibility, and worthy of promotion.

[0005] The technical scheme of the present application is:

[0006] A modular ammonia synthesis reactor with adjustable production capacity, comprising a plurality of single reactors; the inlets of the single reactors are connected in parallel and then connected to a heating device and a feed pipe, and the outlets of the single reactors are connected in parallel and then connected to a discharge pipe; the heating device is electrically connected to a control system; control valves are arranged at the inlets and outlets of the single reactors; the control valves are electrically connected to the control system, so that each single reactor can be controlled to work independently or in combination.

[0007] Further, the single reactor comprises a shell; the shell is cylindrical, and the two ends of the shell are respectively provided with an inlet and an outlet; catalyst I and catalyst II are respectively arranged at the two ends inside the shell; the catalyst I and the catalyst II are arranged at intervals, and a heat exchanger is arranged between the catalyst I and the catalyst II; the heat exchanger is electrically connected to the control system.

[0008] Further, a temperature sensor I is arranged between the catalyst I and the heat exchanger; a temperature sensor II is arranged between the catalyst II and the heat exchanger; the temperature sensor I and the temperature sensor II are electrically connected to the control system.

[0009] Further, the shell is externally provided with a heat preservation layer.

[0010] Further, the heating device is an electric furnace.

[0011] A control method of a modular ammonia synthesis reactor with adjustable capacity comprises the following steps:

[0012] 1) 0%-10% capacity loading: first input a target capacity to the control system, the control system opens the first single reactor, after the gas flow is normal, the electric furnace and the circulating water of the heat exchanger are started, so that the heat exchanger runs at the minimum load; when the temperature measured by the temperature sensor I reaches 450 DEG C, the electric furnace is turned off, the reaction is carried out by itself, and the capacity of the single reactor is adjusted to 5%-10% by adjusting the load of the heat exchanger.

[0013] 2) 10%-20% capacity loading: first input a target capacity to the control system, the control system starts the electric furnace, opens the second single reactor and the second circulating water, and makes the second heat exchanger run at the minimum load; then, the first single reactor is temporarily closed, when the temperature of the temperature sensor I of the second single reactor reaches the set temperature, the first single reactor is opened again, and the electric furnace is turned off, so that the two single reactors work simultaneously to reach the target capacity load.

[0014] 3) 20%-110% loading: temporarily close all normally running single reactors, at the same time, start a new single reactor, when the temperature of the temperature sensor I of the new single reactor reaches the set temperature, all normally running single reactors that are temporarily closed are started again to reach the target capacity load.

[0015] 4) 110%-5% load reduction: input a target capacity to the control system; the control system controls to close corresponding number of single reactors according to the target capacity, only the required single reactors are kept running to reach the target capacity load.

[0016] Further, the set temperature is 450 DEG C.

[0017] Further, the method for closing the single reactor in steps 2), 3) and 4) is to close the control valve at the inlet and outlet of the single reactor.

[0018] The beneficial effects of the present application are as follows:

[0019] The present application

[0020] 1. Through the parallel design of multiple single reactors, the production capacity can be adjusted by 5%-110%, meeting the production needs of different stages.

[0021] 2. When running at low load, the electric furnace does not need to be turned on, reducing energy consumption and environmental pollution, and realizing green production.

[0022] 3. The standardization and serialization of the equipment are realized, which is conducive to large-scale production and application promotion. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structural schematic diagram of the present application.

[0024] Figure 2 is a structural schematic diagram of the single reactor of the present application.

[0025] Among them, 1-heating device; 2-control valve; 3-single reactor; 4-feeding pipe; 5-discharge pipe; 301-housing; 302-catalyst I; 303-catalyst II; 304-heat exchanger; 305-temperature sensor I; 306-temperature sensor II; 307-inlet; 308-outlet. EMBODIMENT

[0026] The present application will be further described below in conjunction with the drawings and examples.

[0027] As shown in Figure 1 and 2 .

[0028] The present application is a modular ammonia synthesis reactor with adjustable production capacity, which comprises a plurality of single reactors 3. In this embodiment, the single reactor is 10.

[0029] The single reactor 3 comprises a housing 301. The housing 301 is a cylindrical closed container, which is externally provided with a heat preservation layer, and is provided with an inlet 307 and an outlet 308 at both ends, respectively, and is internally provided with a catalyst I 302 and a catalyst II 303 at both ends, respectively. The catalyst I 302 and the catalyst II 303 are arranged at intervals, and the catalyst I 302 is adjacent to the inlet 307, and the catalyst II 303 is adjacent to the outlet 308. A heat exchanger 304 is arranged between the catalyst I 302 and the catalyst II 303, so that the raw gas exchanges heat with the heat exchanger. The heat exchanger 304 is electrically connected with the control system, and can be controlled to operate.

[0030] The temperature sensor I 305 is arranged between the catalyst I 302 and the heat exchanger 304, and can detect the temperature of the raw material gas after flowing through the catalyst I 302. The temperature sensor II 306 is arranged between the catalyst II 303 and the heat exchanger 304, and can detect the temperature of the raw material gas after flowing through the heat exchanger. The temperature sensor I 305 and the temperature sensor II 306 are electrically connected to the control system, and can transmit the detected temperature information to the control system.

[0031] The inlets of the plurality of single reactors 3 are connected in parallel and then connected to the heating device 1 and the feed pipe 4 through the heating device 1, and the outlets are connected in parallel and then connected to the discharge pipe 5, forming a modular structure, so that the raw material gas can be distributed to flow through different single reactors. Meanwhile, the inlets and the outlets of the single reactors are respectively provided with control valves 2, so that the raw material gas can be controlled to enter the specified single reactor.

[0032] The control valves 2 are electrically connected to the control system, so that each single reactor can be controlled to work independently or in combination.

[0033] The heating device 1 is an electric furnace, and is electrically connected to the control system, so that it can be controlled to start and stop.

[0034] The control system has a production capacity setting function, which can input a target production capacity, and calculate the number of single reactors to be started and the time of starting the electric furnace according to the target production capacity.

[0035] The working process of the modular ammonia synthesis reactor with adjustable production capacity is as follows:

[0036] The raw material gas (hydrogen and nitrogen) is configured in a ratio of 3:1 and pressurized to 9 MPa. Then, the raw material gas is distributed into the specified single reactor by the control system. The control valve of the single reactor is opened, the raw material gas enters the single reactor from the inlet, contacts the catalyst I to perform the synthesis reaction and releases heat, then sequentially passes through the temperature sensor I, the heat exchanger and the temperature sensor II, and then contacts the catalyst II to continue the reaction, and finally flows out from the outlet. During the process, the temperature sensor I and the temperature sensor II transmit the temperature information to the control system. The control system controls the operation of the electric furnace and the heat exchanger according to the received temperature information, controls the temperature, and ensures that the reaction temperature in the single reactor is in the best state.

[0037] The control method of the modular ammonia synthesis reactor with adjustable production capacity comprises the following steps:

[0038] 1) 0%-10% capacity load, first input target capacity to control system, control system opens first single reactor, after gas flow is normal, open electric furnace and heat exchanger circulating water, make heat exchanger run at minimum load; when temperature sensor I measured temperature reaches 450 DEG C, close electric furnace, make reaction proceed by itself, and control single reactor capacity at 5%-10% by adjusting heat exchanger load;

[0039] 2) 10%-20% capacity load: first input target capacity to control system, control system opens electric furnace, at the same time, open second single reactor and second circulating water, and make second heat exchanger run at minimum load; then, temporarily close first single reactor, when temperature sensor I of second single reactor reaches 450 DEG C, open first single reactor again, and close electric furnace, make two single reactors work simultaneously; the above temporary closing process is about half a minute, because single reactor shell is provided with insulation layer, so that the temperature in temporarily closed single reactor is still in active area, so that it can immediately enter normal working state after being opened again, and then the system reaches target capacity load;

[0040] 3) 20%-110% load: temporarily close all normally running single reactors, at the same time, open new single reactor, when temperature sensor I reaches 450 DEG C, open all normally running single reactors again, reach target capacity load;

[0041] 4) 110%-5% load reduction: input target capacity to control system; control system controls to close corresponding number of single reactors according to target capacity, only keep required single reactors running normally, reach target capacity load.

[0042] The method for closing single reactor in steps 2), 3) and 4) is that control system closes control valve at inlet and outlet of the single reactor.

[0043] The present application realizes large range capacity adjustment by combining multiple single reactors into modular assembly, meets production requirements in different stages, and also can run without electric furnace at low load, reduces energy consumption and environmental pollution, realizes green production, so that standardization and serialization of equipment are realized, which is beneficial to large-scale production and application promotion.

[0044] The part not involved in the present application is same as prior art or can be realized by prior art.

Claims

1. A control method for a modular ammonia synthesis reactor with adjustable capacity, characterized in that, The modular ammonia synthesis reactor comprises multiple individual reactors. The inlets of the individual reactors are connected in parallel and then connected to the feed pipe via a heating device. Their outlets are connected in parallel and then connected to the discharge pipe. The heating device is electrically connected to the control system. Control valves are respectively installed at the inlet and outlet of each individual reactor. These control valves are electrically connected to the control system, enabling each individual reactor to operate independently or in combination under control. The single reactor includes a shell; the shell is cylindrical, with an inlet and an outlet at each end, and catalyst I and catalyst II are respectively installed at both ends inside the shell; catalyst I and catalyst II are spaced apart, with a heat exchanger installed between them; the heat exchanger is electrically connected to the control system. Temperature sensor I is installed between catalyst I and heat exchanger; temperature sensor II is installed between catalyst II and heat exchanger; temperature sensor I and temperature sensor II are electrically connected to the control system respectively. The control method includes the following steps: 1) 0%-10% capacity loading: First, input the target capacity into the control system. The control system opens the first unit reactor. After the gas flow is normal, turn on the electric furnace and heat exchanger circulating water to make the heat exchanger run at the lowest load. When the temperature measured by temperature sensor I reaches the set temperature, turn off the electric furnace and let the reaction proceed automatically. The capacity of the unit reactor is controlled to be adjusted between 5% and 10% by adjusting the load of the heat exchanger. 2) 10%-20% capacity loading: First, input the target capacity into the control system, turn on the electric furnace, and simultaneously turn on the second unit reactor and the second circulating water system, and make the second heat exchanger run at the lowest load; then, temporarily shut down the first unit reactor, and when the temperature sensor I of the second unit reactor reaches 450℃, turn on the first unit reactor again and shut down the electric furnace, so that the two unit reactors work at the same time to achieve the target capacity load; 3) 20%-110% loading: Temporarily shut down all normally operating individual reactors, and at the same time, start a new individual reactor. When the temperature of its temperature sensor I reaches the set temperature, restart all the normally operating individual reactors that were temporarily shut down to achieve the target capacity load. 4) 110% to 5% load reduction: Input the target capacity into the control system; the control system controls the shutdown of the corresponding number of individual reactors according to the target capacity, and keeps only the required individual reactors running normally to achieve the target capacity load.

2. The control method for the modular ammonia synthesis reactor with adjustable capacity according to claim 1, characterized in that, The outer shell is provided with a heat insulation layer.

3. The control method for the modular ammonia synthesis reactor with adjustable capacity according to claim 1, characterized in that, The heating device is an electric furnace.

4. The control method for the modular ammonia synthesis reactor with adjustable capacity according to claim 1, characterized in that, The set temperature is 450℃.

5. The control method for the modular ammonia synthesis reactor with adjustable capacity according to claim 1, characterized in that, The method for shutting down the individual reactor in steps 2), 3), and 4) is to close the control valves at the inlet and outlet of the individual reactor.

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