SCR liquid ammonia pipeline gasification ammonia supply system and control method thereof

Abstract

This invention provides an SCR liquid ammonia pipeline vaporization ammonia supply system and its control method, relating to the field of internal combustion engine exhaust aftertreatment technology. The system includes a liquid ammonia inlet valve connected in series on a liquid ammonia delivery pipe; a heating assembly arranged around the outer periphery of the liquid ammonia delivery pipe for heating the pipe; a temperature detection unit outputting a temperature detection signal; a pressure detection unit outputting a pressure detection signal; a gas-liquid separation and pressure stabilization device connected in series between the vaporization outlet of the liquid ammonia delivery pipe and the ammonia injection actuator for separating liquid ammonia droplets and buffering and stabilizing gaseous ammonia; a flow detection unit outputting a flow detection signal; and a controller that determines the liquid ammonia vaporization state and adjusts the power of the heating assembly, the opening degree of the liquid ammonia inlet valve, and the opening degree of the ammonia injection actuator. The advantages of this invention are that it eliminates the need for a separate vaporizer in the SCR system, significantly simplifies the system structure, and significantly reduces manufacturing costs and installation difficulty.

Description

Technical Field

[0001] This application relates to the field of internal combustion engine exhaust aftertreatment technology, and more specifically, to an SCR liquid ammonia pipeline vaporization ammonia supply system and its control method. Background Technology

[0002] Selective catalytic reduction (SCR) technology is currently the most widely used technology for removing nitrogen oxides from diesel engine exhaust. Liquid ammonia, as a highly efficient reducing agent, has advantages such as high purity and low storage and transportation costs, and is widely used in both stationary and mobile SCR systems.

[0003] Existing SCR liquid ammonia supply systems generally employ an independent vaporizer structure. Liquid ammonia, after being discharged from the storage tank, first enters the independent vaporizer for heating and vaporization before being transported to the ammonia injection actuator via pipeline. This structure has the following drawbacks: the independent vaporizer increases the overall system complexity and manufacturing cost, occupies a large installation space, and is not conducive to system integration and miniaturization design. Heat loss exists between the independent vaporizer and the delivery pipeline, which can easily lead to the re-liquefaction of vaporized ammonia during transportation, affecting the stability of the ammonia supply. Existing systems typically use only a single temperature or pressure parameter to determine the vaporization state, which cannot accurately reflect the actual phase change of liquid ammonia, easily leading to incomplete vaporization or overheating.

[0004] In view of the above, this application is hereby submitted. Summary of the Invention

[0005] The purpose of this application is to provide an SCR liquid ammonia pipeline vaporization ammonia supply system and its control method, which is particularly suitable for simplifying the existing SCR system structure, reducing manufacturing costs, improving the accuracy of liquid ammonia vaporization state judgment, realizing precise linkage control of the ammonia supply process, and improving ammonia supply stability and response speed.

[0006] The technical solution adopted in this invention is as follows: Firstly, an SCR liquid ammonia pipeline vaporization ammonia supply system is provided, applied to an SCR system having a liquid ammonia delivery pipe and an ammonia injection actuator, for supplying gaseous ammonia reducing agent to the SCR reactor, comprising: A liquid ammonia inlet valve is connected in series on the liquid ammonia delivery pipe to regulate the flow rate of liquid ammonia entering the liquid ammonia delivery pipe; A heat tracing assembly is arranged on the outer periphery of the liquid ammonia delivery pipe to heat the liquid ammonia delivery pipe, so that the liquid ammonia can complete the transformation from liquid to gaseous state during the delivery process in the liquid ammonia delivery pipe. A temperature detection unit is installed at the outlet section after vaporization of the liquid ammonia conveying pipe to detect the temperature of the outlet section after vaporization of the liquid ammonia conveying pipe and output a temperature detection signal. A pressure detection unit is installed at the outlet section after vaporization of the liquid ammonia delivery pipe to detect the pressure at the outlet section after vaporization of the liquid ammonia delivery pipe and output a pressure detection signal. A gas-liquid separation and pressure stabilization device is connected in series between the vaporization outlet section of the liquid ammonia conveying pipe and the ammonia injection actuator. It is used to separate liquid ammonia droplets and buffer and stabilize the gaseous ammonia. A flow detection unit is installed on the outlet side of the gas-liquid separation and pressure stabilization device to detect the actual ammonia flow rate output to the SCR reactor and output a flow detection signal. The controller determines the liquid ammonia vaporization state based on the temperature detection signal, the pressure detection signal, and the flow detection signal, and adjusts the power of the heating component, the opening degree of the liquid ammonia inlet valve, and the opening degree of the ammonia injection actuator according to the liquid ammonia vaporization state.

[0007] Furthermore, the heat tracing assembly includes at least two independently controlled heat tracing sections.

[0008] Furthermore, the heat tracing section includes a preheating section, a main vaporization section, and a temperature stabilization section arranged sequentially along the liquid ammonia flow direction. The preheating section is used to initially heat up the liquid ammonia entering the liquid ammonia delivery pipe. The main vaporization section is used to provide the heat required for the liquid ammonia to change from a liquid state to a gaseous state. The temperature stabilization section is used to keep the vaporized ammonia gas in a stable gaseous state.

[0009] Furthermore, the controller independently adjusts the power of each of the heating sections according to the liquid ammonia vaporization state.

[0010] Furthermore, the heat tracing component is an electric heat tracing tape.

[0011] Secondly, a method for controlling the vaporization and ammonia supply in an SCR liquid ammonia pipeline is provided, including the following steps: The liquid ammonia delivery pipe that allows liquid ammonia to enter the SCR system; The liquid ammonia delivery pipe is heated so that the liquid ammonia undergoes a transformation from liquid to gaseous state during its delivery within the pipe. The temperature and pressure at the outlet section of the liquid ammonia delivery pipe after vaporization are detected to obtain temperature detection signals and pressure detection signals. The actual ammonia flow rate output to the SCR reactor is detected to obtain the flow detection signal; The vaporization state of liquid ammonia is determined by combining the temperature detection signal, the pressure detection signal, and the flow detection signal. The heating power, the flow rate of liquid ammonia entering the liquid ammonia delivery pipe, and the flow rate of ammonia gas injected into the SCR reactor are adjusted according to the liquid ammonia vaporization state. After the vaporized ammonia is subjected to gas-liquid separation and pressure stabilization, it is supplied to the SCR reactor.

[0012] Further, heating the liquid ammonia delivery pipe includes the following steps: The liquid ammonia delivery pipe is heated in sections independently; The segmented independent heating steps include: preheating the liquid ammonia, performing main vaporization treatment, and stabilizing the temperature treatment in sequence.

[0013] Furthermore, the steps of adjusting the heating power, the liquid ammonia flow rate entering the liquid ammonia delivery pipe, and the ammonia flow rate injected into the SCR reactor according to the liquid ammonia vaporization state include: when it is determined that the liquid ammonia vaporization is insufficient, increasing the heating power of the liquid ammonia delivery pipe, while reducing the liquid ammonia flow rate and limiting the maximum value of the ammonia flow rate.

[0014] Furthermore, the steps of adjusting the heating power, the flow rate of liquid ammonia entering the liquid ammonia delivery pipe, and the flow rate of ammonia gas injected into the SCR reactor according to the liquid ammonia vaporization state include: when the temperature of the outlet section of the liquid ammonia delivery pipe after vaporization is higher than a preset range, the heating power of the temperature stabilization treatment is reduced first; if the temperature continues to be too high, the heating power of the main vaporization treatment is reduced.

[0015] Furthermore, it also includes the following steps: based on SCR entry NO x The target ammonia demand is determined by the concentration, exhaust flow rate, and target ammonia-nitrogen ratio, and the ammonia flow rate is controlled in a closed loop based on the deviation between the target ammonia demand and the actual ammonia flow rate.

[0016] The advantages and positive effects of this invention are as follows: By adopting the above technical solution, the independent vaporizer is eliminated, the system structure is greatly simplified, the manufacturing cost and installation difficulty are significantly reduced, and the system integration and miniaturization design are facilitated; the liquid ammonia vaporization state is judged by three parameters of temperature, pressure and flow rate, which has higher identification accuracy and effectively avoids the misjudgment problem caused by judging a single parameter; the linkage adjustment of heating power, liquid ammonia inlet flow rate and ammonia injection flow rate is realized, the ammonia supply response speed and stability are significantly improved, and it can better match the changes in engine operating conditions. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a physical connection structure diagram of an SCR liquid ammonia pipeline vaporization ammonia supply system according to an embodiment of the present invention; Figure 2 This is a signal transmission control diagram of an SCR liquid ammonia pipeline vaporization ammonia supply system according to an embodiment of the present invention; Figure 3This is a schematic flowchart of an SCR liquid ammonia pipeline vaporization ammonia supply control method according to an embodiment of the present invention. Detailed Implementation

[0019] The present disclosure will now be described more fully with reference to the accompanying drawings, which illustrate exemplary embodiments of the present disclosure. The technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present disclosure without creative effort are within the scope of protection of the present disclosure.

[0020] like Figure 1 and Figure 2 As shown, this invention provides an SCR liquid ammonia pipeline vaporization ammonia supply system, applied to an SCR system having a liquid ammonia delivery pipe 10 and an ammonia injection actuator 70, for supplying gaseous ammonia reducing agent to the SCR reactor, comprising: A liquid ammonia inlet valve 20 is connected in series on the liquid ammonia delivery pipe 10 and is used to regulate the flow rate of liquid ammonia entering the liquid ammonia delivery pipe 10. The liquid ammonia inlet valve 20 is a valve that can regulate the flow rate of fluid, including but not limited to electric regulating valve, pneumatic regulating valve, electromagnetic regulating valve, and proportional regulating valve. The heat tracing component 30 is arranged on the outer periphery of the liquid ammonia conveying pipe 10 and is used to heat the liquid ammonia conveying pipe 10 so that the liquid ammonia completes the transformation from liquid to gas during the process of being transported in the liquid ammonia conveying pipe 10. The heat tracing component 30 is a device that can heat the pipeline, including but not limited to electric heat tracing tape, steam heat tracing pipe, hot water heat tracing pipe, heat transfer oil heat tracing pipe, and infrared heating device. Temperature detection unit 41 is installed at the vaporization outlet section of liquid ammonia delivery pipe 10. It is used to detect the temperature of the vaporization outlet section of liquid ammonia delivery pipe 10 and output a temperature detection signal. Temperature detection unit 41 is a sensor capable of detecting temperature, including but not limited to platinum resistance temperature sensor, thermocouple temperature sensor, and thermistor temperature sensor. The vaporization outlet section of liquid ammonia delivery pipe refers to the pipe section area along the liquid ammonia flow direction and at the end of the area covered by the heat tracing component. After being heated by the heat tracing component, the liquid ammonia in this area has completed the transformation from liquid to gaseous state and is the output section of gaseous ammonia. The pressure detection unit 42 is installed at the outlet section after vaporization of the liquid ammonia delivery pipe 10. It is used to detect the pressure at the outlet section after vaporization of the liquid ammonia delivery pipe 10 and output a pressure detection signal. The pressure detection unit 42 is a sensor capable of detecting pressure, including but not limited to a diffused silicon pressure transmitter, a capacitive pressure transmitter, and a strain gauge pressure transmitter. A gas-liquid separation and pressure stabilization device 50 is connected in series between the vaporization outlet section of the liquid ammonia conveying pipe 10 and the ammonia injection actuator 70. It is used to separate liquid ammonia droplets and buffer and stabilize the pressure of gaseous ammonia. The gas-liquid separation and pressure stabilization device 50 is a device that can separate gas-liquid mixtures and has a pressure stabilization function, including but not limited to wire mesh gas-liquid separators, cyclone gas-liquid separators, baffle gas-liquid separators, and gravity gas-liquid separators. The flow detection unit 43 is located on the outlet side of the gas-liquid separation and pressure stabilization device 50. It is used to detect the actual ammonia flow rate output to the SCR reactor and output a flow detection signal. The flow detection unit 43 is a sensor that can detect gas flow rate, including but not limited to thermal gas mass flow meter, vortex flow meter, differential pressure flow meter, and ultrasonic flow meter. The controller 60 determines the liquid ammonia vaporization state based on the temperature detection signal, pressure detection signal, and flow detection signal, and adjusts the power of the heating component 30, the opening degree of the liquid ammonia inlet valve 20, and the opening degree of the ammonia injection actuator 70 according to the liquid ammonia vaporization state. The controller 60 is a control unit that can receive detection signals and output control signals, including but not limited to programmable logic controllers (PLCs), microcontrollers, digital signal processors (DSPs), and embedded controllers.

[0021] By adopting the above settings, the independent vaporizer in the SCR system is eliminated, greatly simplifying the system structure and significantly reducing manufacturing costs and installation difficulty; the combined judgment of three parameters—temperature, pressure, and flow rate—makes the vaporization state identification more accurate and avoids misjudgment; and the linkage adjustment of heating power, liquid inlet flow rate, and ammonia injection rate is realized, significantly improving the ammonia supply response speed and stability.

[0022] To address the issues of uneven heating, high energy consumption, and insufficient vaporization caused by the inability of integrated heating systems to match the phase change heat requirements of liquid ammonia along the conveying direction, this embodiment provides an implementation method.

[0023] In one embodiment, the heat tracing assembly includes at least two independently controlled heat tracing sections.

[0024] By adopting the above settings, different areas can be heated differently to accurately match the heat requirements of the liquid ammonia phase change process; effectively improving heating efficiency and reducing the overall energy consumption of the system.

[0025] To address the issue that a simple two-stage approach cannot accurately represent the complete process of liquid ammonia from liquid to heated state, phase change and vaporization, to stable gaseous state, this embodiment provides an implementation method.

[0026] In one embodiment, the heating section includes a preheating section, a main vaporization section, and a temperature stabilization section arranged sequentially along the liquid ammonia flow direction. The preheating section is used to initially heat up the liquid ammonia entering the liquid ammonia delivery pipe, the main vaporization section is used to provide the heat required for the liquid ammonia to change from liquid to gas, and the temperature stabilization section is used to keep the vaporized ammonia gas in a stable gaseous state.

[0027] By adopting the above settings, the thermal characteristics of the three core stages of liquid ammonia preheating, main gasification, and temperature stabilization are precisely matched, effectively preventing liquid ammonia droplet entrainment and ammonia overheating.

[0028] In one embodiment, the heat tracing assembly is divided into two independently controlled heat tracing sections along the liquid ammonia flow direction: a vaporization section and a temperature stabilization section. The vaporization section heats the liquid ammonia and completely vaporizes it, while the temperature stabilization section keeps the vaporized ammonia in a stable gaseous state. The controller independently adjusts the power of the vaporization section and the temperature stabilization section according to the vaporization state of the liquid ammonia.

[0029] In one embodiment, the heat tracing assembly uses a steam heat tracing pipe, arranged parallel to the outside of the liquid ammonia delivery pipe. The steam heat tracing pipe is divided into multiple independently controlled sections, each equipped with a steam regulating valve. The controller controls the heating power by adjusting the opening degree of the steam regulating valves in each section, thereby achieving the segmented vaporization of liquid ammonia.

[0030] In one embodiment, the controller independently adjusts the power of each heating section according to the vaporization state of the liquid ammonia.

[0031] In one embodiment, the controller uses a fuzzy control algorithm instead of a conventional PID control algorithm. The controller takes temperature deviation, pressure deviation, and flow deviation as inputs, and after fuzzification, fuzzy inference, and defuzzification processing, outputs the adjustment amounts of heating power, liquid ammonia inlet valve opening, and ammonia injection actuator opening, further improving control accuracy and response speed.

[0032] In one embodiment, the heat tracing component is an electric heat tracing tape.

[0033] In one embodiment, the heat tracing assembly is covered with an insulation layer made of aluminum silicate cotton with a thickness of 20-50 mm. The insulation layer can effectively reduce heat loss from the heat tracing assembly, improve heating efficiency, and reduce system energy consumption.

[0034] In one embodiment, a spring-loaded safety valve is installed at the top of the gas-liquid separation pressure stabilizing device, with a set pressure of 1.6 MPa. When the system pressure exceeds the set pressure, the safety valve automatically opens to release pressure and prevent the system from being damaged by overpressure.

[0035] In one embodiment, the heat tracing assembly uses a self-regulating electric heat tracing tape, which can be arranged on the outer periphery of the liquid ammonia delivery pipe by spiral winding, axial application, or segmented wrapping.

[0036] In one embodiment, the controller dynamically limits the opening degree of the ammonia injection actuator based on the liquid ammonia vaporization state. When insufficient liquid ammonia vaporization is detected, the controller limits the maximum opening degree of the ammonia injection actuator even if the target ammonia demand increases, to prevent liquid ammonia droplets from entering the SCR reactor. Once the liquid ammonia vaporization state returns to normal, the controller gradually releases the ammonia injection opening degree limit and resumes normal PID control.

[0037] In one embodiment, the system further includes an ammonia leak detector installed around the liquid ammonia delivery pipe and the heat tracing assembly. The ammonia leak detector can detect the ammonia concentration in the environment in real time, and when the concentration exceeds a preset threshold, it issues an alarm signal and triggers an emergency shut-off valve.

[0038] In one embodiment, an emergency shut-off valve is installed at the outlet of the liquid ammonia storage tank and is electrically connected to the controller. When the system detects ammonia leakage, overpressure, or other abnormal conditions, the controller immediately closes the emergency shut-off valve to cut off the liquid ammonia supply and ensure system safety.

[0039] like Figure 3 As shown, in order to better utilize an SCR liquid ammonia pipeline vaporization ammonia supply system, this application also provides an SCR liquid ammonia pipeline vaporization ammonia supply control method, including the following steps: S100, the liquid ammonia delivery pipe that allows liquid ammonia to enter the SCR system; S200. The liquid ammonia delivery pipe is heated so that the liquid ammonia changes from a liquid to a gaseous state during the delivery process in the liquid ammonia delivery pipe. S300: Detects the temperature and pressure at the outlet section of the liquid ammonia delivery pipe after vaporization, and obtains temperature and pressure detection signals. S400: Detect the actual ammonia flow rate output to the SCR reactor to obtain the flow detection signal; S500: The vaporization state of liquid ammonia is determined by combining temperature detection signal, pressure detection signal and flow detection signal. S600, adjust the heating power, the flow rate of liquid ammonia entering the liquid ammonia delivery pipe, and the flow rate of ammonia gas injected into the SCR reactor according to the liquid ammonia vaporization state. S700 processes the vaporized ammonia gas through gas-liquid separation and pressure stabilization before supplying it to the SCR reactor.

[0040] Using the above method, the entire process of liquid ammonia pipeline vaporization and ammonia supply can be automated without manual intervention; the control logic is highly matched with the pipeline vaporization characteristics, and the stability and reliability of ammonia supply are significantly improved.

[0041] In one embodiment, heating the liquid ammonia delivery pipe includes the following steps: The liquid ammonia delivery pipe is heated in sections independently; The steps of segmented independent heating include: preheating liquid ammonia, main vaporization treatment, and temperature stabilization treatment in sequence.

[0042] In one embodiment, the steps of adjusting the heating power, the liquid ammonia flow rate into the liquid ammonia delivery pipe, and the ammonia flow rate injected into the SCR reactor according to the liquid ammonia vaporization state include: when it is determined that the liquid ammonia vaporization is insufficient, increasing the heating power of the liquid ammonia delivery pipe, while reducing the liquid ammonia flow rate and limiting the maximum value of the ammonia flow rate.

[0043] In one embodiment, the steps of adjusting the heating power, the flow rate of liquid ammonia entering the liquid ammonia delivery pipe, and the flow rate of ammonia injected into the SCR reactor according to the liquid ammonia vaporization state include: when the temperature of the outlet section of the liquid ammonia delivery pipe after vaporization is higher than a preset range, the heating power of the temperature stabilization treatment is reduced first; if the temperature continues to be too high, the heating power of the main vaporization treatment is reduced.

[0044] In one embodiment, the method further includes the following step: based on the SCR inlet NO x The target ammonia demand is determined by the concentration, exhaust flow rate, and target ammonia-nitrogen ratio, and the ammonia flow rate is controlled in a closed loop based on the deviation between the target ammonia demand and the actual ammonia flow rate.

[0045] This embodiment provides a preferred implementation method and describes in detail the specific structure and working process of the core technical solution of this application.

[0046] The SCR liquid ammonia pipeline vaporization ammonia supply system is applied to diesel engine SCR systems with liquid ammonia delivery pipes and ammonia injection actuators. A liquid ammonia outlet is located at the bottom of the liquid ammonia storage tank, connected to the liquid ammonia delivery pipe. An electrically controlled liquid ammonia inlet valve is connected in series at the inlet end of the liquid ammonia delivery pipe. The heat tracing assembly uses self-regulating electric heating tape, spirally wound around the outer circumference of the liquid ammonia delivery pipe. The heat tracing assembly is divided into three independently controlled sections along the liquid ammonia flow direction: a preheating section, a main vaporization section, and a temperature stabilization section. The preheating section is located near the inlet of the liquid ammonia delivery pipe, the main vaporization section is located in the middle of the liquid ammonia delivery pipe, and the temperature stabilization section is located upstream of the vaporization outlet section of the liquid ammonia delivery pipe.

[0047] Both the temperature and pressure detection units employ industrial-grade sensors and are installed at the vaporization outlet of the liquid ammonia delivery pipe. The flow detection unit uses a thermal gas mass flow meter and is installed on the outlet side of the gas-liquid separation and pressure stabilization device. The gas-liquid separation and pressure stabilization device is a wire mesh gas-liquid separator, connected in series between the vaporization outlet of the liquid ammonia delivery pipe and the ammonia injection actuator. The controller uses a PLC and is electrically connected to the liquid ammonia inlet valve, the three heating sections, the temperature detection unit, the pressure detection unit, the flow detection unit, and the ammonia injection actuator.

[0048] The system operates as follows: After liquid ammonia is output from the liquid ammonia storage tank, its flow rate is regulated by the liquid ammonia inlet valve before entering the liquid ammonia delivery pipe. The heating assembly heats the liquid ammonia delivery pipe; the preheating section initially raises the temperature of the liquid ammonia entering the pipe; the main vaporization section provides the primary heat required for the phase change of liquid ammonia, causing it to transform into a gaseous state; and the temperature stabilization section maintains the vaporized ammonia in a stable gaseous state. The vaporized ammonia then enters the gas-liquid separation and pressure stabilization device, which separates any entrained liquid ammonia droplets and performs buffering and pressure stabilization. The flow detection unit detects the actual output ammonia flow rate. The controller jointly determines the liquid ammonia vaporization state based on the temperature, pressure, and flow rate detection signals, and independently adjusts the power of the three heating sections, the opening of the liquid ammonia inlet valve, and the opening of the ammonia injection actuator according to the vaporization state, achieving precise control of the ammonia supply process.

[0049] The system startup control process is as follows: When the system starts, the controller first opens the preheating section and the main vaporization section to preheat the liquid ammonia delivery pipe. After the liquid ammonia delivery pipe reaches the preset preheating conditions, the controller opens the liquid ammonia inlet valve to allow liquid ammonia to enter the liquid ammonia delivery pipe.

[0050] The system shutdown control process is as follows: When the system shuts down, the controller first reduces or closes the liquid ammonia inlet valve to stop new liquid ammonia from entering the liquid ammonia delivery pipe. Subsequently, the controller maintains the heat tracing operation of the main vaporization section and the temperature stabilization section, allowing the residual liquid ammonia in the liquid ammonia delivery pipe to continue to vaporize and be discharged. When the actual ammonia flow rate drops below the preset value, the controller shuts down the ammonia injection actuator and the heat tracing components.

[0051] Based on embodiments of this disclosure, this disclosure also provides an electronic device, a readable storage medium, and a computer program product.

[0052] An electronic device includes at least one processor and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the SCR liquid ammonia pipeline vaporization ammonia supply control method provided in this disclosure.

[0053] Electronic devices are intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0054] A non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to cause a computer to execute the SCR liquid ammonia pipeline vaporization ammonia supply control method provided in this disclosure.

[0055] The various embodiments of this disclosure can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0056] A computer program product includes a computer program / instructions, which are executed by a processor to control the vaporization and ammonia supply of an SCR liquid ammonia pipeline as disclosed herein.

[0057] The program code used to implement the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0058] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0059] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. An SCR liquid ammonia pipeline vaporization ammonia supply system, characterized in that, Applied to SCR systems with liquid ammonia delivery pipes and ammonia injection actuators, used to supply gaseous ammonia reducing agent to the SCR reactor, including: A liquid ammonia inlet valve is connected in series on the liquid ammonia delivery pipe to regulate the flow rate of liquid ammonia entering the liquid ammonia delivery pipe; A heat tracing assembly is arranged on the outer periphery of the liquid ammonia delivery pipe to heat the liquid ammonia delivery pipe, so that the liquid ammonia can complete the transformation from liquid to gaseous state during the delivery process in the liquid ammonia delivery pipe. A temperature detection unit is installed at the outlet section after vaporization of the liquid ammonia conveying pipe to detect the temperature of the outlet section after vaporization of the liquid ammonia conveying pipe and output a temperature detection signal. A pressure detection unit is installed at the outlet section after vaporization of the liquid ammonia delivery pipe to detect the pressure at the outlet section after vaporization of the liquid ammonia delivery pipe and output a pressure detection signal. A gas-liquid separation and pressure stabilization device is connected in series between the vaporization outlet section of the liquid ammonia conveying pipe and the ammonia injection actuator. It is used to separate liquid ammonia droplets and buffer and stabilize the gaseous ammonia. A flow detection unit is installed on the outlet side of the gas-liquid separation and pressure stabilization device to detect the actual ammonia flow rate output to the SCR reactor and output a flow detection signal. The controller determines the liquid ammonia vaporization state based on the temperature detection signal, the pressure detection signal, and the flow detection signal, and adjusts the power of the heating component, the opening degree of the liquid ammonia inlet valve, and the opening degree of the ammonia injection actuator according to the liquid ammonia vaporization state.

2. The system according to claim 1, characterized in that: The heat tracing assembly includes at least two independently controlled heat tracing sections.

3. The system according to claim 2, characterized in that: The heat tracing section includes a preheating section, a main vaporization section, and a temperature stabilization section arranged sequentially along the liquid ammonia flow direction. The preheating section is used to initially heat up the liquid ammonia entering the liquid ammonia delivery pipe. The main vaporization section is used to provide the heat required for the liquid ammonia to change from a liquid state to a gaseous state. The temperature stabilization section is used to keep the vaporized ammonia gas in a stable gaseous state.

4. The system according to claim 2 or 3, characterized in that: The controller independently adjusts the power of each of the heating sections according to the liquid ammonia vaporization state.

5. The system according to claim 1, characterized in that: The heat tracing component is an electric heat tracing tape.

6. A method for controlling the vaporization and ammonia supply in an SCR liquid ammonia pipeline, characterized in that, Includes the following steps: The liquid ammonia delivery pipe that allows liquid ammonia to enter the SCR system; The liquid ammonia delivery pipe is heated so that the liquid ammonia undergoes a transformation from liquid to gaseous state during its delivery within the pipe. The temperature and pressure at the outlet section of the liquid ammonia delivery pipe after vaporization are detected to obtain temperature detection signals and pressure detection signals. The actual ammonia flow rate output to the SCR reactor is detected to obtain the flow detection signal; The vaporization state of liquid ammonia is determined by combining the temperature detection signal, the pressure detection signal, and the flow detection signal. The heating power, the flow rate of liquid ammonia entering the liquid ammonia delivery pipe, and the flow rate of ammonia gas injected into the SCR reactor are adjusted according to the liquid ammonia vaporization state. After the vaporized ammonia is subjected to gas-liquid separation and pressure stabilization, it is supplied to the SCR reactor.

7. The method according to claim 6, characterized in that, Heating the liquid ammonia delivery pipe includes the following steps: The liquid ammonia delivery pipe is heated in sections independently; The segmented independent heating steps include: preheating the liquid ammonia, performing main vaporization treatment, and stabilizing the temperature treatment in sequence.

8. The method according to claim 6, characterized in that, The steps of adjusting the heating power, the liquid ammonia flow rate into the liquid ammonia delivery pipe, and the ammonia flow rate injected into the SCR reactor according to the liquid ammonia vaporization state include: when it is determined that the liquid ammonia vaporization is insufficient, increasing the heating power of the liquid ammonia delivery pipe, while reducing the liquid ammonia flow rate and limiting the maximum value of the ammonia flow rate.

9. The method according to claim 7, characterized in that, The steps of adjusting the heating power, the flow rate of liquid ammonia entering the liquid ammonia delivery pipe, and the flow rate of ammonia injected into the SCR reactor according to the liquid ammonia vaporization state include: when the temperature of the outlet section of the liquid ammonia delivery pipe after vaporization is higher than a preset range, the heating power of the temperature stabilization treatment is reduced first; if the temperature continues to be too high, the heating power of the main vaporization treatment is reduced.

10. The method according to claim 6, characterized in that, It also includes the following steps: According to SCR entry NO x The target ammonia demand is determined by the concentration, exhaust flow rate, and target ammonia-nitrogen ratio, and the ammonia flow rate is controlled in a closed loop based on the deviation between the target ammonia demand and the actual ammonia flow rate.

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