Liquid ammonia driving system principle for blending combustion of boiler unit and control method

Abstract

The invention discloses a liquid ammonia driving system principle for boiler unit blending combustion and a control method. Comprising a first liquid ammonia storage tank, a second liquid ammonia storage tank, a first liquid ammonia storage tank liquid level display device, a second liquid ammonia storage tank liquid level display device, a liquid ammonia pump inlet control module, a liquid ammonia pump backflow gas ammonia control block, a liquid ammonia working pump, a working driving motor, a liquid ammonia standby pump, a standby driving motor, a liquid ammonia pump circulating water control module and a nitrogen purging control block. The invention relates to the technical field of ammonia-doped combustion of coal-fired boilers, in particular to an ammonia-doped combustion control system of a coal-fired boiler. According to the principle and control method of the liquid ammonia driving system for blending combustion of the boiler unit, by adopting a control algorithm of a variable frequency driving control technology and a fuzzy PID (Proportion Integration Differentiation) technology, the rotating speed of a motor is steplessly adjusted, so that the output power of the motor is matched with the rotating speed, flexible regulation and control, energy conservation and noise reduction of the system on the liquid ammonia driving system can be realized, and the requirement of the unit on the ammonia doping amount is met.

Description

Technical Field

[0001] The invention relates to the technical field of ammonia-blended combustion in coal-fired boilers, and in particular to a liquid ammonia driving system principle and a control method for blending combustion in a boiler unit. Background Art

[0002] Ammonia is a good carrier of hydrogen. Compared with hydrogen, it has a higher hydrogen content and higher volume energy density. It is easy to liquefy for transportation and storage, and has high safety. It can effectively serve as a carrier of hydrogen and energy, and is considered to be a more promising clean fuel. Using ammonia as a substitute for fossil fuels and replacing part of fossil fuels with equal calorific value to enter the boiler for blending can effectively reduce carbon emissions.

[0003] At present, thermal power companies mainly use ammonia for desulfurization and denitrification processes. Since gaseous ammonia is usually used, the amount used is small and the transportation distance is short. At room temperature, the pressure of liquid ammonia itself can basically meet the process needs of desulfurization and denitrification.

[0004] However, if ammonia is blended as fuel, the amount of ammonia blended is large and the transportation distance is long. At the same time, the pressure and characteristics of liquid ammonia vary greatly with the ambient temperature. It is easy to vaporize at room temperature, and its liquid ammonia pressure is low at low temperatures. Regardless of whether it is in gaseous or liquid form during blending, it is impossible to provide stable and reliable liquid ammonia fuel, resulting in an extremely unstable ammonia supply during blending, which cannot meet the ammonia blending demand of the boiler unit, and seriously affects the normal operation of the coal-fired unit. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a liquid ammonia driving system principle and control method for the co-firing of a boiler unit, which solves the problem that the amount of ammonia co-firing in the boiler unit is unstable and cannot be burned safely and efficiently.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a liquid ammonia drive system for boiler unit blending, comprising a first liquid ammonia storage tank, a second liquid ammonia storage tank, a liquid level display device for the first liquid ammonia storage tank, a liquid ammonia storage tank liquid level display device, a liquid ammonia pump inlet control module, a liquid ammonia pump reflux gas ammonia control block, a liquid ammonia working pump, a working drive motor, a liquid ammonia standby pump, a standby drive motor, a liquid ammonia pump circulating water control module, a nitrogen purge control block, a liquid ammonia pump outlet control module, a liquid ammonia pump reflux gas ammonia control module, an external electronic control system, a liquid ammonia output port and a liquid ammonia pipeline nitrogen purge control block in the ammonia storage area, the first liquid ammonia storage tank liquid level display module The liquid level display device is arranged on the first liquid ammonia storage tank, the liquid level display device of the second liquid ammonia storage tank is arranged on the second liquid ammonia storage tank, the liquid ammonia pump inlet control module is arranged on the first liquid ammonia storage tank and the second liquid ammonia storage tank, the liquid ammonia pump inlet control module is connected with the liquid ammonia pump reflux gas ammonia control block, the liquid ammonia pump reflux gas ammonia control block is arranged on the liquid ammonia working pump, the working drive motor is connected with the liquid ammonia working pump, the liquid ammonia standby pump and the standby drive motor are connected with the liquid ammonia working pump, the liquid ammonia output port is arranged on the liquid ammonia working pump, and the liquid ammonia pump circulating water control module, the nitrogen purge control block and the liquid ammonia pump outlet control module are arranged on the liquid ammonia working pump.

[0007] Preferably, the liquid ammonia pump inlet control module includes a filter, a manual ball valve at the front end of the liquid ammonia pump inlet pneumatic valve, a liquid ammonia pump inlet pneumatic valve, a liquid ammonia pump inlet pneumatic bypass manual ball valve, a liquid ammonia pump inlet safety valve, a manual ball valve at the front end of the liquid ammonia pump inlet safety valve, a liquid ammonia pump inlet pressure sensor, a liquid ammonia pump inlet thermometer, a liquid ammonia working pump inlet manual ball valve, a liquid ammonia working pump inlet pneumatic valve, a liquid ammonia standby pump inlet manual ball valve, and a liquid ammonia standby pump inlet pneumatic valve.

[0008] Preferably, the liquid ammonia pump circulating water control module includes a liquid ammonia standby pump inlet manual stop valve, a liquid ammonia working pump inlet manual stop valve, a circulating water flow meter, a circulating water inlet electric valve, a circulating water return port and a circulating water inlet.

[0009] Preferably, the nitrogen purge control block comprises a nitrogen purge port at a working pump outlet, a nitrogen purge port at a pump reflux port, a nitrogen purge port at a standby pump outlet and a nitrogen purge port at a pump inlet, and a check valve and a stop valve are provided on the nitrogen purge control block.

[0010] Preferably, the liquid ammonia pump outlet control module includes a manual ball valve at the liquid ammonia main outlet bypass, a ball valve behind the pneumatic ball valve at the liquid ammonia main outlet, a pneumatic ball valve at the liquid ammonia main outlet, a ball valve in front of the pneumatic ball valve at the liquid ammonia main outlet, a spare liquid ammonia pump outlet check valve, a liquid ammonia main flowmeter, a spare liquid ammonia pump outlet manual ball valve, a pump outlet on-site pressure gauge, a working liquid ammonia pump outlet check valve, a working liquid ammonia pump outlet manual ball valve, a liquid ammonia pump outlet pressure sensor, a manual ball valve at the front end of the liquid ammonia pump outlet safety valve, a liquid ammonia pump outlet safety valve, a normal pressure liquid ammonia outlet pneumatic ball valve, a liquid ammonia reflux port mass flowmeter and a normal pressure liquid ammonia outlet manual ball valve.

[0011] Preferably, the liquid ammonia pump reflux gas ammonia control module includes a liquid ammonia reflux first manual ball valve, a liquid ammonia reflux pneumatic regulating valve, a liquid ammonia reflux second manual ball valve, a liquid ammonia reflux pneumatic valve and a liquid ammonia reflux third manual ball valve.

[0012] Preferably, the nitrogen purge control block of the liquid ammonia pipeline in the ammonia storage area includes a nitrogen bottle storage station, a nitrogen inlet stop valve, a flexible joint, a pressure gauge before the manual pressure regulating valve, a manual pressure regulating valve, a pressure gauge after the manual pressure regulating valve, a nitrogen inlet temperature gauge, a nitrogen inlet check valve, a stop valve before the safety valve, a safety valve, a nitrogen purge branch control block, a nitrogen purge first branch first inlet stop valve, a nitrogen purge first branch first inlet check valve, a nitrogen purge first branch first inlet, a nitrogen purge first branch second inlet, a nitrogen purge first branch third inlet and a nitrogen purge first branch fourth inlet.

[0013] Preferably, the nitrogen inlet stop valve is arranged on the nitrogen bottle storage station, one end of the nitrogen inlet stop valve is connected to the flexible joint, the pressure gauge before the manual pressure regulating valve, the manual pressure regulating valve, the pressure gauge after the manual pressure regulating valve and the nitrogen inlet temperature gauge are all arranged on the flexible joint, one end of the flexible joint is connected to the nitrogen inlet check valve, the nitrogen inlet check valve is connected to the stop valve before the safety valve, and the stop valve before the safety valve is connected to the safety valve.

[0014] Preferably, the nitrogen cylinder storage station is connected to the fourth inlet of the first branch of nitrogen purge, the first inlet stop valve of the first branch of nitrogen purge and the first inlet check valve of the first branch of nitrogen purge are arranged on the nitrogen purge branch control block, and the first inlet of the first branch of nitrogen purge, the second inlet of the first branch of nitrogen purge, the third inlet of the first branch of nitrogen purge and the fourth inlet of the first branch of nitrogen purge are arranged on the nitrogen purge branch control block.

[0015] The present invention also discloses a liquid ammonia driving control method for ammonia-blended combustion in a coal-fired boiler, which specifically comprises the following steps:

[0016] Step 1: The system is in an unstarted state. When the system inputs a work instruction, the instruction is transmitted to the liquid ammonia pump electronic control system to request a task. The liquid ammonia pump electronic control system receives the instruction. The liquid ammonia pump inlet control module, the liquid ammonia pump outlet control module, the liquid ammonia pump reflux gas ammonia control module, the liquid ammonia pump water circulation control module, the liquid ammonia storage tank liquid level control module, and the alarm system control module receive the instruction issued by the liquid ammonia pump electronic control system. The liquid ammonia pump electronic control system detects and monitors the liquid ammonia pump inlet control module, the liquid ammonia pump outlet control module, the liquid ammonia pump reflux gas ammonia control module, the liquid ammonia pump water circulation control module, the liquid ammonia storage tank liquid level control module, and the alarm system control module. If the startup conditions cannot be met, the inspection is stopped, and the cycle is repeated after the fault is eliminated.

[0017] Step 2: The system meets the start-up conditions, and the liquid ammonia pump inlet control module, the liquid ammonia pump outlet control module, the liquid ammonia pump reflux gas ammonia control module, the liquid ammonia pump water circulation control module, the liquid ammonia storage tank liquid level control module and the alarm system control module are started, and the liquid ammonia pump system works;

[0018] Step 3, the system sets the amount of liquid ammonia according to the amount of ammonia blending, inputs the liquid ammonia setting value and the liquid ammonia reflux detection signal into the first comparator for comparison, calculates the actual output flow rate of the liquid ammonia driving pump, and transmits it to the system controller. The system controller receives the output value of the first comparator, transmits the output value of the first comparator to the driving pump frequency conversion controller, the driving pump frequency conversion controller receives the output signal of the system controller, and calculates the speed of the variable frequency motor through the frequency conversion controller, and transmits it to the variable frequency motor. The variable frequency motor receives the output signal of the variable frequency controller and controls the speed of the variable frequency motor. The rotation of the variable frequency motor drives the driving pump to output the set liquid ammonia flow rate, and the actual liquid ammonia flow rate is measured by the liquid ammonia flowmeter set in the pipeline and fed back to the second comparator for comparison. The second comparator receives the liquid ammonia setting value and the liquid ammonia flowmeter detection value and compares them. The comparison result of the second comparator is transmitted to the controller of the liquid ammonia reflux regulating valve to control the opening of the regulating valve. The liquid ammonia reflux regulating valve detects the opening of the regulating valve and generates an output signal through the processor, which is transmitted to the first comparator for comparison, thereby completing a control cycle;

[0019] Step 4: When the system issues a stop command or a manual stop signal, the system receives and stops working instructions. When the system receives a fault signal, an ammonia combustion leak detector alarm, an abnormal signal, or a manual stop signal, the system alarms, the system sends a signal, and the system stops working and resets.

[0020] Beneficial Effects

[0021] The present invention provides a liquid ammonia drive system principle and control method for boiler unit co-firing. Compared with the existing technology, it has the following beneficial effects:

[0022] (1) The present invention adopts the control algorithm of variable frequency drive control technology and fuzzy PID technology, controls the frequency converter through PLC, and steplessly adjusts the speed of the motor to match the motor output power, thereby realizing the system's flexible regulation and control of the liquid ammonia drive system and energy saving and noise reduction, meeting the unit's ammonia blending requirements, providing liquid ammonia fuel with a certain flow rate and pressure, ensuring a stable and reliable liquid ammonia fuel power source, and having a large liquid ammonia adjustment range. The liquid ammonia pressure can be adjusted according to the working conditions to meet the needs of large-scale blending of gaseous ammonia and liquid ammonia, thereby realizing the energy transformation of coal-fired units and the replacement of fossil fuels, and effectively reducing carbon emissions.

[0023] (2) The present invention can realize automatic adjustment and monitoring of the amount of liquid ammonia in the ammonia blending process by adopting advanced PLC, human-machine interface technology and visual monitoring technology. The operator can view the production status, adjust the ammonia blending process parameters and handle abnormal situations in real time through the human-machine interface.

[0024] (3) The present invention adopts a dual-circuit liquid ammonia drive system and is provided with a liquid ammonia reflux circuit to supply the system in an orderly manner, thereby controlling the flow rate of the system, ensuring the safety and reliability of the system, and realizing a stable supply of liquid ammonia fuel to the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the liquid ammonia driving principle of the ammonia storage area of ​​the present invention;

[0026] Figure 2 This is a schematic diagram of nitrogen purge of liquid ammonia pipeline in the ammonia storage area of ​​the present invention;

[0027] Figure 3 This is a control workflow diagram of the liquid ammonia pump system of the present invention;

[0028] Figure 4 This is a control block diagram of the variable frequency liquid ammonia pump of the present invention.

[0029] In the figure: 1. First liquid ammonia storage tank; 2. Liquid ammonia pump inlet control module; 3. Liquid ammonia pump reflux gas ammonia control block; 4. Liquid ammonia working pump; 5. Working drive motor; 6. Liquid ammonia standby pump; 7. Standby drive motor; 8. Liquid ammonia pump circulating water control module; 9. Nitrogen purge control block; 10. Liquid ammonia pump outlet control module; 11. Liquid ammonia pump reflux gas ammonia control module; 12. Second liquid ammonia storage tank liquid level display device; 13. Second liquid ammonia storage tank; 14. First liquid ammonia storage tank liquid level display device; 15. External electronic control system; 16. Liquid ammonia outlet; 17. Liquid ammonia pipeline nitrogen purge control block in ammonia storage area; 201. Filter; 202. Manual ball valve at the front end of the liquid ammonia pump inlet pneumatic valve; 203. Liquid ammonia pump inlet pneumatic valve; 204. Liquid ammonia Pneumatic bypass manual ball valve at pump inlet; 205, liquid ammonia pump inlet safety valve; 206, manual ball valve at the front end of liquid ammonia pump inlet safety valve; 207, liquid ammonia pump inlet pressure sensor; 208, liquid ammonia pump inlet thermometer; 209, liquid ammonia working pump inlet manual ball valve; 210, liquid ammonia working pump inlet pneumatic valve; 211, liquid ammonia standby pump inlet manual ball valve; 212, liquid ammonia standby pump inlet pneumatic valve; 801, liquid ammonia standby pump inlet manual stop valve; 802, liquid ammonia working pump inlet manual stop valve; 803, circulating water flow meter; 804, circulating water inlet electric valve; 805, circulating water return port; 806, circulating water inlet; 901, check valve; 902, stop valve; 903, working pump outlet nitrogen purge port; 90 4. Nitrogen purge port at pump reflux port; 905. Nitrogen purge port at standby pump outlet; 906. Nitrogen purge port at pump inlet; 1001. Manual ball valve at bypass of liquid ammonia main outlet; 1002. Ball valve at rear side of pneumatic ball valve at liquid ammonia main outlet; 1003. Pneumatic ball valve at liquid ammonia main outlet; 1004. Ball valve at front side of pneumatic ball valve at liquid ammonia main outlet; 1005. Check valve at standby liquid ammonia pump outlet; 1006. Flowmeter at liquid ammonia main outlet; 1007. Manual ball valve at standby liquid ammonia pump outlet; 1008. On-site pressure gauge at pump outlet; 1009. Check valve at working liquid ammonia pump outlet; 1010. Manual ball valve at working liquid ammonia pump outlet; 1011. Pressure sensor at liquid ammonia pump outlet; 1012. Manual ball valve at front end of safety valve at liquid ammonia pump outlet; 1013. Liquid Ammonia pump outlet safety valve; 1014, atmospheric pressure liquid ammonia outlet pneumatic ball valve; 1015, liquid ammonia reflux port mass flowmeter; 1016, atmospheric pressure liquid ammonia outlet manual ball valve; 1101, liquid ammonia reflux first manual ball valve; 1102, liquid ammonia reflux pneumatic regulating valve; 1103, liquid ammonia reflux second manual ball valve; 1104, liquid ammonia reflux pneumatic valve; 1105, liquid ammonia reflux third manual ball valve; 1701, nitrogen bottle storage station; 1702, nitrogen inlet stop valve; 1703, flexible joint; 1704, manual pressure regulating valve front pressure gauge; 1705, manual pressure regulating valve; 1706, manual pressure regulating valve rear pressure gauge; 1707, nitrogen inlet temperature gauge; 1708, nitrogen inlet check valve; 1709, safety valve front stop valve;1710, safety valve; 1711, nitrogen purge branch control block; 1712, nitrogen purge first branch first inlet stop valve; 1713, nitrogen purge first branch first inlet check valve; 1714, nitrogen purge first branch first inlet; 1715, nitrogen purge first branch second inlet; 1716, nitrogen purge first branch third inlet; 1717, nitrogen purge first branch fourth inlet. ; DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0031] See also Figure 1-4 The present invention provides a technical solution: a liquid ammonia drive system for boiler unit blending, comprising a first liquid ammonia storage tank 1, a second liquid ammonia storage tank 13, a first liquid ammonia storage tank liquid level display device 14, a second liquid ammonia storage tank liquid level display device 12, a liquid ammonia pump inlet control module 2, a liquid ammonia pump reflux gas ammonia control block 3, a liquid ammonia working pump 4, a working drive motor 5, a liquid ammonia standby pump 6, a standby drive motor 7, a liquid ammonia pump circulating water control module 8, a nitrogen purge control block 9, a liquid ammonia pump outlet control module 10, a liquid ammonia pump reflux gas ammonia control module 11, an external electric control system 15, a liquid ammonia output port 16 and a liquid ammonia pipeline nitrogen purge control block 17 in the ammonia storage area, a first liquid ammonia storage tank liquid level display module 2, a liquid ammonia pump reflux gas ammonia control block 3, a liquid ammonia working pump 4, a working drive motor 5, a liquid ammonia standby pump 6, a standby drive motor 7, a liquid ammonia pump circulating water control module 8, a nitrogen purge control block 9, a liquid ammonia pump outlet control module 10, a liquid ammonia pump reflux gas ammonia control module 11, an external electric control system 15, a liquid ammonia output port 16 and a liquid ammonia pipeline nitrogen purge control block 17 in the ammonia storage area, a liquid ammonia storage tank liquid level display module 2, a liquid ammonia pump reflux gas ammonia control module 3, a liquid ammonia working pump 4, a working drive motor 5, a liquid ammonia standby pump 6, a standby drive motor 7, a liquid ammonia pump circulating water control module 8, a nitrogen purge control block 9, a liquid ammonia pump outlet control module 10, a liquid a The display device 14 is arranged on the first liquid ammonia storage tank 1, the second liquid ammonia storage tank liquid level display device 12 is arranged on the second liquid ammonia storage tank 13, the liquid ammonia pump inlet control module 2 is arranged on the first liquid ammonia storage tank 1 and the second liquid ammonia storage tank 13, the liquid ammonia pump inlet control module 2 is connected to the liquid ammonia pump reflux gas ammonia control block 3, the liquid ammonia pump reflux gas ammonia control block 3 is arranged on the liquid ammonia working pump 4, the working drive motor 5 is connected to the liquid ammonia working pump 4, the liquid ammonia standby pump 6 and the standby drive motor 7 are connected to the liquid ammonia working pump 4, the liquid ammonia output port 16 is arranged on the liquid ammonia working pump 4, the liquid ammonia pump circulating water control module 8, the nitrogen purge control block 9 and the liquid ammonia pump outlet control module 10 are arranged on the liquid ammonia working pump 4.

[0032] Furthermore, the liquid ammonia pump inlet control module 2 includes a filter 201, a manual ball valve 202 at the front end of the liquid ammonia pump inlet pneumatic valve, a liquid ammonia pump inlet pneumatic valve 203, a liquid ammonia pump inlet pneumatic bypass manual ball valve 204, a liquid ammonia pump inlet safety valve 205, a manual ball valve 206 at the front end of the liquid ammonia pump inlet safety valve, a liquid ammonia pump inlet pressure sensor 207, a liquid ammonia pump inlet thermometer 208, a liquid ammonia working pump inlet manual ball valve 209, a liquid ammonia working pump inlet pneumatic valve 210, a liquid ammonia standby pump inlet manual ball valve 211, and a liquid ammonia standby pump inlet pneumatic valve 212.

[0033] Furthermore, the liquid ammonia pump circulating water control module 8 includes a liquid ammonia standby pump inlet manual stop valve 801, a liquid ammonia working pump inlet manual stop valve 802, a circulating water flow meter 803, a circulating water inlet electric valve 804, a circulating water return port 805 and a circulating water inlet 806.

[0034] Furthermore, the nitrogen purge control block 9 includes a nitrogen purge port 903 at the outlet of the working pump, a nitrogen purge port 904 at the reflux port of the pump, a nitrogen purge port 905 at the outlet of the standby pump and a nitrogen purge port 906 at the inlet of the pump, and a check valve 901 and a stop valve 902 are provided on the nitrogen purge control block 9.

[0035] Furthermore, the liquid ammonia pump outlet control module 10 includes a liquid ammonia main outlet bypass manual ball valve 1001, a liquid ammonia main outlet pneumatic ball valve rear side ball valve 1002, a liquid ammonia main outlet pneumatic ball valve 1003, a liquid ammonia main outlet pneumatic ball valve front side ball valve 1004, a standby liquid ammonia pump outlet check valve 1005, a liquid ammonia main outlet flowmeter 1006, a standby liquid ammonia pump outlet manual ball valve 1007, a pump outlet on-site pressure gauge 1008, a working liquid ammonia pump outlet check valve 1009, a working liquid ammonia pump outlet manual ball valve 1010, a liquid ammonia pump outlet pressure sensor 1011, a liquid ammonia pump outlet safety valve front end manual ball valve 1012, a liquid ammonia pump outlet safety valve 1013, a normal pressure liquid ammonia outlet pneumatic ball valve 1014, a liquid ammonia reflux port mass flowmeter 1015 and a normal pressure liquid ammonia outlet manual ball valve 1016.

[0036] Furthermore, the liquid ammonia pump reflux gas ammonia control module 11 includes a liquid ammonia reflux first manual ball valve 1101, a liquid ammonia reflux pneumatic regulating valve 1102, a liquid ammonia reflux second manual ball valve 1103, a liquid ammonia reflux pneumatic valve 1104 and a liquid ammonia reflux third manual ball valve 1105.

[0037] Furthermore, the nitrogen purge control block 17 of the liquid ammonia pipeline in the ammonia storage area includes a nitrogen bottle storage station 1701, a nitrogen inlet stop valve 1702, a flexible joint 1703, a pressure gauge 1704 before the manual pressure regulating valve, a manual pressure regulating valve 1705, a pressure gauge 1706 after the manual pressure regulating valve, a nitrogen inlet temperature gauge 1707, a nitrogen inlet check valve 1708, a stop valve 1709 before the safety valve, a safety valve 1710, a nitrogen purge branch control block 1711, and a nitrogen purge The first branch first inlet stop valve 1712, the first branch first inlet check valve 1713 of nitrogen purge, the first branch first inlet 1714 of nitrogen purge, the first branch second inlet 1715 of nitrogen purge, the first branch third inlet 1716 of nitrogen purge and the first branch fourth inlet 1717 of nitrogen purge, the nitrogen inlet stop valve 1702 is arranged on the nitrogen bottle storage station 1701, and one end of the nitrogen inlet stop valve 1702 is connected to the flexible joint 1703 The pressure gauge 1704 before the manual pressure regulating valve, the manual pressure regulating valve 1705, the pressure gauge 1706 after the manual pressure regulating valve and the nitrogen inlet temperature gauge 1707 are all arranged on the flexible joint 1703. One end of the flexible joint 1703 is connected to the nitrogen inlet check valve 1708. The nitrogen inlet check valve 1708 is connected to the stop valve 1709 before the safety valve. The stop valve 1709 before the safety valve is connected to the safety valve 1710. The nitrogen bottle storage station 1701 is connected to the first nitrogen purge The fourth inlet 1717 of the branch is connected, the first inlet stop valve 1712 of the first inlet of the nitrogen purge first branch and the first inlet check valve 1713 of the first inlet of the nitrogen purge first branch are arranged on the nitrogen purge branch control block 1711, and the first inlet 1714 of the nitrogen purge first branch, the second inlet 1715 of the nitrogen purge first branch, the third inlet 1716 of the nitrogen purge first branch and the fourth inlet 1717 of the nitrogen purge first branch are arranged on the nitrogen purge branch control block 1711.

[0038] The present invention also discloses a liquid ammonia driving control method for ammonia-blended combustion in a coal-fired boiler, which specifically comprises the following steps:

[0039] Step 1, the system is in an unstarted state. When the system inputs a work instruction, the instruction is transmitted to the liquid ammonia pump electronic control system to request a task. The liquid ammonia pump electronic control system receives the instruction. The liquid ammonia pump inlet control module 2, the liquid ammonia pump outlet control module 10, the liquid ammonia pump reflux gas ammonia control module 3, the liquid ammonia pump water circulation control module 8, the liquid ammonia storage tank liquid level control module, and the alarm system control module receive the instruction issued by the liquid ammonia pump electronic control system. The liquid ammonia pump electronic control system detects and monitors the liquid ammonia pump inlet control module 2, the liquid ammonia pump outlet control module 10, the liquid ammonia pump reflux gas ammonia control module 3, the liquid ammonia pump water circulation control module 10, the liquid ammonia storage tank liquid level control module, and the alarm system control module. If the startup conditions cannot be met, the inspection is stopped, and the cycle is repeated after the fault is eliminated;

[0040] Step 2: The system meets the start-up conditions, starts the liquid ammonia pump inlet control module 2, the liquid ammonia pump outlet control module 10, the liquid ammonia pump reflux gas ammonia control module 3, the liquid ammonia pump water circulation control module 10, the liquid ammonia storage tank liquid level control module and the alarm system control module, and the liquid ammonia pump system works;

[0041] Step 3, the system sets the amount of liquid ammonia according to the amount of ammonia blending, inputs the liquid ammonia setting value and the liquid ammonia reflux detection signal into the first comparator for comparison, calculates the actual output flow rate of the liquid ammonia driving pump, and transmits it to the system controller. The system controller receives the output value of the first comparator, transmits the output value of the first comparator to the driving pump frequency conversion controller, the driving pump frequency conversion controller receives the output signal of the system controller, and calculates the speed of the variable frequency motor through the frequency conversion controller, and transmits it to the variable frequency motor. The variable frequency motor receives the output signal of the variable frequency controller and controls the speed of the variable frequency motor. The rotation of the variable frequency motor drives the driving pump to output the set liquid ammonia flow rate, and the actual liquid ammonia flow rate is measured by the liquid ammonia flowmeter set in the pipeline and fed back to the second comparator for comparison. The second comparator receives the liquid ammonia setting value and the liquid ammonia flowmeter detection value and compares them. The comparison result of the second comparator is transmitted to the controller of the liquid ammonia reflux regulating valve to control the opening of the regulating valve. The liquid ammonia reflux regulating valve detects the opening of the regulating valve and generates an output signal through the processor, which is transmitted to the first comparator for comparison, thereby completing a control cycle;

[0042] Step 4: When the system issues a stop command or a manual stop signal, the system receives and stops working instructions. When the system receives a fault signal, an ammonia combustion leak detector alarm, an abnormal signal, or a manual stop signal, the system alarms, the system sends a signal, and the system stops working and resets.

Claims

1. A liquid ammonia drive system for boiler unit blending, comprising a first liquid ammonia storage tank (1), a second liquid ammonia storage tank (13), a first liquid ammonia storage tank liquid level display device (14), a second liquid ammonia storage tank liquid level display device (12), a liquid ammonia pump inlet control module (2), a liquid ammonia pump reflux gas ammonia control block (3), a liquid ammonia working pump (4), a working drive motor (5), a liquid ammonia standby pump (6), a standby drive motor (7), a liquid ammonia pump circulating water control module (8), a nitrogen purge control block (9), a liquid ammonia pump outlet control module (10), a liquid ammonia pump reflux gas ammonia control module (11), an external electric control system (15), a liquid ammonia output port (16) and a liquid ammonia pipeline nitrogen purge control block (17) in the ammonia storage area, characterized in that: The first liquid ammonia storage tank liquid level display device (14) is arranged on the first liquid ammonia storage tank (1), the second liquid ammonia storage tank liquid level display device (12) is arranged on the second liquid ammonia storage tank (13), the liquid ammonia pump inlet control module (2) is arranged on the first liquid ammonia storage tank (1) and the second liquid ammonia storage tank (13), the liquid ammonia pump inlet control module (2) is connected to the liquid ammonia pump reflux gas ammonia control block (3), the liquid ammonia pump reflux gas ammonia control block (3) is arranged on the liquid ammonia working pump (4), the working drive motor (5) is connected to the liquid ammonia working pump (4), the liquid ammonia standby pump (6) and the standby drive motor (7) are connected to the liquid ammonia working pump (4), the liquid ammonia output port (16) is arranged on the liquid ammonia working pump (4), and the liquid ammonia pump circulating water control module (8), the nitrogen purge control block (9) and the liquid ammonia pump outlet control module (10) are arranged on the liquid ammonia working pump (4).

2. A liquid ammonia driving system for boiler unit blending according to claim 1, characterized in that: The liquid ammonia pump inlet control module (2) comprises a filter (201), a manual ball valve (202) at the front end of the liquid ammonia pump inlet pneumatic valve, a liquid ammonia pump inlet pneumatic valve (203), a liquid ammonia pump inlet pneumatic bypass manual ball valve (204), a liquid ammonia pump inlet safety valve (205), a manual ball valve (206) at the front end of the liquid ammonia pump inlet safety valve, a liquid ammonia pump inlet pressure sensor (207), a liquid ammonia pump inlet thermometer (208), a liquid ammonia working pump inlet manual ball valve (209), a liquid ammonia working pump inlet pneumatic valve (210), a liquid ammonia standby pump inlet manual ball valve (211), and a liquid ammonia standby pump inlet pneumatic valve (212).

3. The liquid ammonia driving system for boiler unit blending according to claim 1, characterized in that: The liquid ammonia pump circulating water control module (8) comprises a liquid ammonia standby pump inlet manual stop valve (801), a liquid ammonia working pump inlet manual stop valve (802), a circulating water flow meter (803), a circulating water inlet electric valve (804), a circulating water return port (805) and a circulating water inlet (806).

4. The liquid ammonia driving system for boiler unit blending according to claim 1, characterized in that: The nitrogen purge control block (9) comprises a nitrogen purge port (903) at the outlet of a working pump, a nitrogen purge port (904) at the reflux port of a pump, a nitrogen purge port (905) at the outlet of a standby pump and a nitrogen purge port (906) at the inlet of a pump. A check valve (901) and a stop valve (902) are provided on the nitrogen purge control block (9).

5. The liquid ammonia driving system for boiler unit blending according to claim 1, characterized in that: The liquid ammonia pump outlet control module (10) comprises a liquid ammonia main pipe outlet bypass manual ball valve (1001), a liquid ammonia main pipe outlet pneumatic ball valve rear side ball valve (1002), a liquid ammonia main pipe outlet pneumatic ball valve (1003), a liquid ammonia main pipe outlet pneumatic ball valve front side ball valve (1004), a standby liquid ammonia pump outlet check valve (1005), a liquid ammonia main pipe flow meter (1006), a standby liquid ammonia pump outlet manual ball valve (1007), a pump outlet local pressure gauge (1008), a working liquid ammonia pump outlet check valve (1009), a working liquid ammonia pump outlet manual ball valve (1010), a liquid ammonia pump outlet pressure sensor (1011), a liquid ammonia pump outlet safety valve front side manual ball valve (1012), a liquid ammonia pump outlet safety valve (1013), a normal pressure liquid ammonia outlet pneumatic ball valve (1014), a liquid ammonia reflux port mass flow meter (1015) and a normal pressure liquid ammonia outlet manual ball valve (1016).

6. The liquid ammonia driving system for boiler unit blending according to claim 1, characterized in that: The liquid ammonia pump reflux gas ammonia control module (11) comprises a liquid ammonia reflux first manual ball valve (1101), a liquid ammonia reflux pneumatic regulating valve (1102), a liquid ammonia reflux second manual ball valve (1103), a liquid ammonia reflux pneumatic valve (1104) and a liquid ammonia reflux third manual ball valve (1105).

7. The liquid ammonia driving system for boiler unit blending according to claim 1 is characterized in that: The ammonia storage area liquid ammonia pipeline nitrogen purge control block (17) comprises a nitrogen bottle storage station (1701), a nitrogen inlet stop valve (1702), a flexible joint (1703), a pressure gauge before a manual pressure regulating valve (1704), a manual pressure regulating valve (1705), a pressure gauge after a manual pressure regulating valve (1706), a nitrogen inlet temperature gauge (1707), a nitrogen inlet check valve (1708), a stop valve before a safety valve (1709), a safety valve (1710), a nitrogen purge branch control block (1711), a nitrogen purge first branch first inlet stop valve (1712), a nitrogen purge first branch first inlet check valve (1713), a nitrogen purge first branch first inlet (1714), a nitrogen purge first branch second inlet (1715), a nitrogen purge first branch third inlet (1716) and a nitrogen purge first branch fourth inlet (1717).

8. The liquid ammonia driving system for boiler unit blending according to claim 7, characterized in that: The nitrogen inlet stop valve (1702) is arranged on the nitrogen bottle storage station (1701), one end of the nitrogen inlet stop valve (1702) is connected to the flexible joint (1703), the pressure gauge (1704) before the manual pressure regulating valve, the manual pressure regulating valve (1705), the pressure gauge (1706) after the manual pressure regulating valve and the nitrogen inlet temperature gauge (1707) are all arranged on the flexible joint (1703), one end of the flexible joint (1703) is connected to the nitrogen inlet check valve (1708), the nitrogen inlet check valve (1708) is connected to the stop valve (1709) before the safety valve, and the stop valve (1709) before the safety valve is connected to the safety valve (1710).

9. The liquid ammonia driving system for boiler unit blending according to claim 7, characterized in that: The nitrogen bottle storage station (1701) is connected to the fourth inlet (1717) of the first branch of nitrogen purge, the first inlet stop valve (1712) of the first branch of nitrogen purge and the first inlet check valve (1713) of the first branch of nitrogen purge are arranged on the nitrogen purge branch control block (1711), and the first inlet (1714) of the first branch of nitrogen purge, the second inlet (1715) of the first branch of nitrogen purge, the third inlet (1716) of the first branch of nitrogen purge and the fourth inlet (1717) of the first branch of nitrogen purge are arranged on the nitrogen purge branch control block (1711).

10. A liquid ammonia driving control method for ammonia-blended combustion in a coal-fired boiler, characterized in that: The specific steps include: Step 1: The system is in an unstarted state. When the system inputs a work instruction, the instruction is transmitted to the liquid ammonia pump electronic control system to request a task. The liquid ammonia pump electronic control system receives the instruction. The liquid ammonia pump inlet control module (2), the liquid ammonia pump outlet control module (10), the liquid ammonia pump reflux gas ammonia control module (3), the liquid ammonia pump water circulation control module (8), the liquid ammonia storage tank liquid level control module, and the alarm system control module receive the instruction issued by the liquid ammonia pump electronic control system. The liquid ammonia pump electronic control system detects and monitors the liquid ammonia pump inlet control module (2), the liquid ammonia pump outlet control module (10), the liquid ammonia pump reflux gas ammonia control module (3), the liquid ammonia pump water circulation control module (10), the liquid ammonia storage tank liquid level control module, and the alarm system control module. If the start-up conditions cannot be met, the inspection is stopped, and the cycle is restarted after the fault is eliminated. Step 2: When the system meets the start-up conditions, the liquid ammonia pump inlet control module (2), the liquid ammonia pump outlet control module (10), the liquid ammonia pump reflux gas ammonia control module (3), the liquid ammonia pump water circulation control module (10), the liquid ammonia storage tank liquid level control module and the alarm system control module are started, and the liquid ammonia pump system starts working; Step 3, the system sets the amount of liquid ammonia according to the amount of ammonia blending, inputs the liquid ammonia setting value and the liquid ammonia reflux detection signal into the first comparator for comparison, calculates the actual output flow rate of the liquid ammonia driving pump, and transmits it to the system controller. The system controller receives the output value of the first comparator, transmits the output value of the first comparator to the driving pump frequency conversion controller, the driving pump frequency conversion controller receives the output signal of the system controller, and calculates the speed of the variable frequency motor through the frequency conversion controller, and transmits it to the variable frequency motor. The variable frequency motor receives the output signal of the variable frequency controller and controls the speed of the variable frequency motor. The rotation of the variable frequency motor drives the driving pump to output the set liquid ammonia flow rate, and the actual liquid ammonia flow rate is measured by the liquid ammonia flowmeter set in the pipeline and fed back to the second comparator for comparison. The second comparator receives the liquid ammonia setting value and the liquid ammonia flowmeter detection value and compares them. The comparison result of the second comparator is transmitted to the controller of the liquid ammonia reflux regulating valve to control the opening of the regulating valve. The liquid ammonia reflux regulating valve detects the opening of the regulating valve and generates an output signal through the processor, which is transmitted to the first comparator for comparison, thereby completing a control cycle; Step 4: When the system issues a stop command or a manual stop signal, the system receives and stops working instructions. When the system receives a fault signal, an ammonia combustion leak detector alarm, an abnormal signal, or a manual stop signal, the system alarms, the system sends a signal, and the system stops working and resets.

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