Gas-fired boiler electrical control simulation device

Abstract

The electrical control simulation device for the gas-fired boiler simulates electrical control of the gas-fired boiler through the PLC, is simple, light, easy to move and convenient to carry, can comprehensively simulate the running state of the gas-fired boiler and simulate general faults in the running process of the gas-fired boiler, is high in automation degree and stable in performance, does not have site limitation on training of maintenance personnel any more, and is suitable for popularization and application. The maintenance capability of the maintenance personnel on the whole electrical control system of the gas boiler is improved, and the professional skill level of the maintenance personnel is enhanced.

Description

Technical Field

[0001] The utility model belongs to the technical field of electrical control training devices for maintenance electricians, in particular to an electrical control simulation device for a gas boiler. Background Art

[0002] With the improvement of environmental protection requirements and the promotion of clean energy policies, gas boilers have been widely used in society as an efficient and environmentally friendly heating equipment. Our company has fully adopted gas boilers to replace coal-fired boilers. The electrical control part of the gas boiler has a high degree of automation and has multiple safety protection functions. Once a fault occurs in the electrical system, maintenance personnel are required to quickly eliminate the fault to avoid production safety accidents. Maintenance personnel not only need to understand the electrical control system of the gas boiler, but also need to perform actual operations to deal with possible faults. Novice maintenance personnel can only learn troubleshooting maintenance skills from experienced masters when the electrical control system of the gas boiler encounters problems. The learning time is not free, and the practice time is limited. They cannot quickly master maintenance skills. Unskilled operation when encountering problems in the electrical control system of the gas boiler may bring safety hazards. Utility Model Content

[0003] The utility model aims to solve the problem that novice maintenance personnel can only learn the maintenance skills of troubleshooting from experienced masters when they encounter problems in the electrical control system of a gas boiler, and the learning time is not free, and the practice time is limited, so they cannot quickly master the maintenance skills. Therefore, a gas boiler electrical control simulation device is provided, which has free learning time and can flexibly simulate common faults of the electrical control system of the gas boiler. By artificially designing faults, the maintenance personnel can have a comprehensive understanding of the electrical control system of the gas boiler and master the skills of troubleshooting.

[0004] In order to achieve the above-mentioned utility model object, the utility model provides a gas boiler electrical control simulation device, including three-phase power supplies L1, L2, L3, 3P air switch QFI, inverter, three-phase motor M, PLC, PLC expansion module, 2P air switch QF2, 2P air switch QF3, DC power supply, DC voltage generator;

[0005] The three-phase power supply L1, L2, L3, 3P circuit breaker QFI, inverter and three-phase motor M are connected in sequence.

[0006] The input terminals I0.0, I0.1, I0.2, I0.3, I0.4, I0.5 and I0.6 of the PLC are respectively connected to the start button SB1, the stop button SB2, the emergency stop button SB3, the first transfer switch SA1, the second transfer switch SA2, the third transfer switch SA3, the fourth transfer switch SA4 and the fifth transfer switch SA5;

[0007] The output terminals Q0.0, Q0.1, Q0.2, Q0.3, Q0.4, Q0.5, Q0.6, Q0.7, Q1.0, and Q1.1 of the PLC are connected to relays KA1, KA2, KA3, KA4, KA5, KA6, KA7, KA8, KA9, and KA10 respectively;

[0008] The output terminals Q.0, Q.1 and Q.2 of the PLC expansion module are connected to the first indicator light HL1, the second indicator light HL2 and the third indicator light HL3 respectively;

[0009] The three-phase power supply L1 and N line are connected to the upper side of the 2P circuit breaker QF2, and the lower side of the 2P circuit breaker QF2 is connected to the PLC power terminals AC and N. The power terminal AC is short-circuited with the PLC terminals 1L, 2L, 3L and the PLC expansion module 1L terminal as the 220V voltage live wire, and the power terminal N is short-circuited with the relays KA1, KA2, KA3, KA4, KA5, KA6, KA7, KA8, KA9, KA10, HL1, HL2, and HL3 as the 220V voltage neutral line. The PLC terminals M and M1 are short-circuited as the 24V negative voltage, and the PLC terminal L+ is connected with SB1, SB2, SB3, SA1, SA2, SA3, SA4, and SA5 as the 24V positive voltage;

[0010] The three-phase power supply L2 and the N line are connected to the upper side of the 2P circuit breaker QF3, and the lower side of the 2P circuit breaker QF3 is connected to the DC power supply, DC voltage generator, and the control terminals AI1 and AGDN of the inverter in sequence;

[0011] The inverter control terminal +24V and DI1 lead wire are connected in series with the KA1 normally open contact;

[0012] PLC control function: After pressing the start button SB1, the PLC terminal Q0.0 output makes the KA1 relay energized and closed, simulating the start of the boiler; 3 seconds later, the PLC expansion module Q.0 output makes the HL1 indicator light up, simulating the pre-purge of the boiler, and it goes out 30 seconds after lighting up, simulating the completion of the pre-purge; at the same time, the PLC terminals Q0.2, Q0.3 and the PLC expansion module terminal Q.2 output make the KA3 and KA4 relays energized and closed and the HL3 indicator light up, respectively simulating the opening of the air supply valve and the gas supply valve and the normal water level status. These three conditions are used as the burner start conditions. When these three conditions are met at the same time, the PLC terminal Q0.4 output makes the KA5 relay energized and closed 3S later, simulating the start-up and operation of the boiler burner;

[0013] After pressing the stop button SB2, the output of PLC terminal Q0.1 and PLC extension module terminal Q.1 causes the KA2 relay to be energized and closed, simulating the boiler stop state. The HL2 indicator light turns on for 30 seconds and then turns off, simulating the post-purge of the boiler. At the same time, the output of PLC terminals Q0.0, Q0.2, Q0.3, Q0.4 and PLC extension module terminal Q.2 is stopped, causing KA1, KA3, KA4, KA5, and HL3 to be disconnected, stopping the boiler.

[0014] When starting, press the emergency stop button SB3 to stop the output of PLC terminals Q0.0, Q0.2, Q0.3, Q0.4, and PLC expansion module terminal Q.2 to disconnect KA1, KA3, KA4, KA5, and HL3, and stop the boiler;

[0015] When starting, the conversion switch SA1 is rotated to close the SA1 contact, simulating that the boiler water level is low at this time. The PLC terminal Q0.5 output makes the KA6 relay energized and attracted, which serves as a low boiler water level alarm prompt; when starting, the conversion switch SA2 is rotated to close the SA2 contact, simulating that the boiler water level is extremely low at this time. The PLC terminal Q0.6 output makes the KA7 relay energized and attracted, and KA7 is connected in series to the boiler operation program loop as a boiler operation protection. When the water level is extremely low, the PLC terminals Q0.0, Q0.2, Q0.3, Q0.4, and the PLC extension module terminal Q.2 outputs disconnect KA1, KA3, KA4, KA5, and HL3 to stop the boiler; when starting, the conversion switch SA3 is rotated to close the SA3 contact, simulating that the boiler water level is high at this time. The PLC terminal Q0.7 output makes the KA8 relay energized and attracted, which serves as a high boiler water level alarm prompt; when starting, the conversion switch SA4 is rotated to close the S A4 contact is closed, simulating that the boiler water level is extremely high at this time. The output of PLC terminal Q1.0 makes the KA9 relay energized and attracted. KA9 is connected in series to the boiler operation program loop as boiler operation protection. When the water level is extremely high, the output of PLC terminals Q0.0, Q0.2, Q0.3, Q0.4 and PLC extension module terminal Q.2 stops KA1, KA3, KA4, KA5 and HL3, and the boiler stops running. When starting, the conversion switch SA5 is rotated to close the SA5 contact, simulating that the gas pressure in the furnace exceeds the limit at this time. The output of PLC terminal 1.1 makes the KA10 relay energized and attracted. KA10 is connected in series to the boiler operation program loop as boiler operation protection. When the gas pressure in the furnace exceeds the limit, the output of PLC terminals Q0.0, Q0.2, Q0.3, Q0.4 and PLC extension module terminal Q.2 stops KA1, KA3, KA4, KA5 and HL3, and the boiler stops running.

[0016] The three-phase power supply L3 and N line are connected to the upper side of the 2P circuit breaker QF4. The terminals L6 and N on the lower side of the 2P circuit breaker QF4 are 220V voltage power supplies. L6 is the 220V voltage live wire, which is respectively connected to the upper ends of the normally open points of relays KA1, KA2, KA3, KA4, KA5, KA6, KA7, KA8, KA9, and KA10. N is the 220V voltage neutral line, which is respectively connected to the indicator lights HL4, HL5, HL6, HL7, HL8, HL9, HL10, HL11, HL12, and HL13. The lower ends of the normally open points of relays KA1, KA2, KA3, KA4, KA5, KA6, KA7, KA8, KA9, and KA10 are connected to the indicator lights HL4, HL5, HL6, HL7, HL8, HL9, HL10, HL11, HL12, and HL13.

[0017] When the normally open point of relay KA1 is closed, the indicator light HL4 lights up, which serves as an indication of boiler operation; when the normally open point of relay KA2 is closed, the indicator light HL5 lights up, which serves as an indication of boiler stop; when the normally open point of relay KA3 is closed, the indicator light HL6 lights up, which serves as an indication of air supply valve opening; when the normally open point of relay KA4 is closed, the indicator light HL7 lights up, which serves as an indication of gas valve opening; when the normally open point of relay KA5 is closed, the indicator light HL8 lights up, which serves as a burner operation indication; when the normally open point of relay KA6 is closed, the indicator light HL9 lights up, which serves as a low water level alarm indication; when the normally open point of relay KA7 is closed, the indicator light HL10 lights up, which serves as an extremely low water level alarm indication; when the normally open point of relay KA8 is closed, the indicator light HL11 lights up, which serves as a high water level alarm indication; when the normally open point of relay KA9 is closed, the indicator light HL12 lights up, which serves as an extremely high water level alarm indication; when the normally open point of relay KA10 is closed, the indicator light HL13 lights up, which serves as an over-limit gas pressure alarm indication.

[0018] Furthermore, it also includes a touch screen HMI, and the touch screen HMI and PLC are connected through a network cable, and the two components communicate and interconnect to realize touch screen control and operation data feedback.

[0019] The utility model gas boiler electrical control simulation device simulates the electrical control of the gas boiler through PLC, is simple and light, easy to move and carry, and can meet the needs of personnel training anytime and anywhere. This device can fully simulate the operating state of the gas boiler and simulate the general faults in the operation of the gas boiler. It has a high degree of automation and stable performance. The training of maintenance personnel is no longer restricted by the site, and the maintenance personnel's maintenance ability of the entire electrical control system of the gas boiler is improved, and the professional skills of the maintenance personnel are strengthened.

[0020] The main features of the gas boiler electrical control simulation device are that the equipment wiring and programming are simple and easy to understand, easy to operate, and the device can simulate the actual operating state of the gas boiler through electrical connections between various components, and can simulate common faults during operation to train employees, which has great promotion value. The use of the gas boiler electrical control simulation device can free up the learning time of maintenance personnel, and can flexibly simulate common faults of the gas boiler electrical control system. By artificially designing faults, maintenance personnel can have a comprehensive understanding of the gas boiler electrical control system, and the purpose of simulation training for maintenance personnel can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The electrical principle of the utility model gas boiler electrical control simulation device Figure 1 ;

[0022] Figure 2 The electrical principle of the utility model gas boiler electrical control simulation device Figure 2 ;

[0023] Figure 3 This is a connection diagram of the utility model gas boiler electrical control simulation device. DETAILED DESCRIPTION

[0024] In order to better understand the purpose, structure and function of the utility model, the following is a further detailed description of a gas boiler electrical control simulation device of the utility model in conjunction with the accompanying drawings.

[0025] Reference Figures 1 to 3 The gas boiler electrical control simulation device includes three-phase power supply L1, L2, L3, 3P air switch QF1, inverter, three-phase motor M, PLC, PLC expansion module, 2P air switch QF2, 2P air switch QF3, DC power supply, DC voltage generator, touch screen HMI, Figure 1 is the electrical schematic diagram of this device, and the following is an analysis of the schematic diagram.

[0026] The three-phase power supplies L1, L2, L3, 3P circuit breaker QFI, inverter and three-phase motor M are connected in sequence.

[0027] The input terminals I0.0, I0.1, I0.2, I0.3, I0.4, I0.5, and I0.6 of the PLC are respectively connected to the start button SB1, the stop button SB2, the emergency stop button SB3, the first transfer switch SA1, the second transfer switch SA2, the third transfer switch SA3, the fourth transfer switch SA4, and the fifth transfer switch SA5; the output terminals Q0.0, Q0.1, Q0.2, Q0.3, Q0.4, Q0.5, Q0.6, Q0.7, Q1.0, and Q1.1 of the PLC are respectively connected to the relays KA1, KA2, KA3, KA4, KA5, KA6, KA7, KA8, KA9, and KA10; the output terminals Q.0, Q.1, and Q.2 of the PLC expansion module are respectively connected to the first indicator light HL1, the second indicator light HL2, and the third indicator light HL3.

[0028] The three-phase power supply L1 and N line are connected to the upper side of the 2P circuit breaker QF2, and the lower side of the 2P circuit breaker QF2 is connected to the PLC power terminals AC and N. The power terminal AC is short-circuited with the PLC terminals 1L, 2L, 3L and the PLC expansion module 1L terminal as the 220V voltage live wire, the power terminal N is short-circuited with the relays KA1, KA2, KA3, KA4, KA5, KA6, KA7, KA8, KA9, KA10, HL1, HL2, and HL3 as the 220V voltage neutral line, the PLC terminals M and M1 are short-circuited as the 24V negative voltage, and the PLC terminal L+ is connected with SB1, SB2, SB3, SA1, SA2, SA3, SA4, and SA5 as the 24V positive voltage.

[0029] The three-phase power supply L2 and the N line are connected to the upper side of the 2P circuit breaker QF3, and the lower side of the 2P circuit breaker QF3 is connected to the DC power supply, DC voltage generator, and the inverter control terminal AI1 and AGDN terminals in sequence. The inverter control terminal +24V and DI1 lead wires are connected in series with the KA1 normally open contact.

[0030] The gas boiler electrical control simulation device uses Siemens S7-200 controller as the main control element. This element has excellent performance and reliability, diversified input and output points, low cost, simple programming and easy operation, simple maintenance and easy learning, and is particularly suitable for program control of this device. A DC voltage generator is used as the frequency adjustment element of the inverter, which has strong anti-interference ability, high control accuracy, stable performance, simple operation and convenient installation. The use of inverters to control and protect the motor can better exert the performance of the motor, protect the safe and reliable operation of the motor, and improve the utilization rate of electric energy. The touch screen is used as the operation and status monitoring element, which is simple and intuitive to operate. Users can operate by touching the screen. It has strong integration and compatibility, can be connected to various models of PLC, has built-in multiple control functions, operation status monitoring, timing control, electrical control, etc., and has a wide range of applicability.

[0031] The panel of the gas boiler electrical control simulation device is equipped with air switches, relays, buttons, PLC, inverter, DC power supply, touch screen, conversion switch, DC voltage generator, etc.

[0032] The touch screen HMI and PLC are connected via a network cable, and the two components communicate and interconnect to achieve touch screen control and operation data feedback.

[0033] Speed ​​regulation function of the frequency converter: This function adopts manual DC voltage signal generator adjustment. The output leads of the DC signal generator are respectively connected to the inverter control terminals AI1 and AGDN. The output frequency of the frequency converter is adjusted by adjusting the 0-10V voltage of the DC voltage signal generator, thereby changing the number of motor speeds.

[0034] The starting function of the inverter: This function adopts the external terminal control method, connecting the inverter control terminal +24V and DI1 lead wire in series with the KA1 normally open contact. When the KA1 coil is energized, the KA1 normally open contact closes to short-circuit +24V and DI1, and the inverter receives the starting signal. It then starts according to the starting method set for the inverter. After starting, it runs according to the frequency set by the DC voltage signal generator.

[0035] PLC control function:

[0036] After pressing the start button SB1, the PLC terminal Q0.0 output causes the KA1 relay to be energized and closed, simulating the start of the boiler; 3 seconds later, the PLC expansion module Q.0 output causes the HL1 indicator to light up, simulating the pre-purge of the boiler to remove dust, oil residue and other debris in the furnace and flue, improve combustion efficiency and reduce flue gas emissions. It goes out 30 seconds after lighting up, simulating the completion of the pre-purge; at the same time, the PLC terminals Q0.2, Q0.3 and the PLC expansion module terminal Q.2 output cause the KA3 and KA4 relays to be energized and the HL3 indicator to light up, respectively simulating the opening of the air supply valve and the gas supply valve and the normal water level status. These three conditions are used as the burner start-up conditions. When these three conditions are met at the same time, the PLC terminal Q0.4 output causes the KA5 relay to be energized and closed 3S later, simulating the start-up of the boiler burner.

[0037] After pressing the stop button SB2, the output of PLC terminal Q0.1 and PLC expansion module terminal Q.1 causes the KA2 relay to be energized and energized, simulating the boiler stop state. The HL2 indicator light turns on for 30 seconds and then goes out, simulating the post-purge of the boiler. The purpose is to remove incompletely burned pulverized coal and combustible gases that may remain in the furnace, flue, air preheater, etc. after the boiler is running, to prevent explosion at the next ignition and ensure the safety of the boiler. At the same time, the output of PLC terminals Q0.0, Q0.2, Q0.3, Q0.4 and PLC expansion module terminal Q.2 is stopped to disconnect KA1, KA3, KA4, KA5, and HL3, causing the boiler to stop running.

[0038] When starting, press the emergency stop button SB3 to stop the output of PLC terminals Q0.0, Q0.2, Q0.3, Q0.4 and PLC expansion module terminal Q.2 to disconnect KA1, KA3, KA4, KA5 and HL3, and stop the boiler. This is used in emergency situations.

[0039] When starting, the conversion switch SA1 is rotated to close the SA1 contact, simulating that the boiler water level is low at this time. The PLC terminal Q0.5 output makes the KA6 relay energized and attracted, which serves as a low boiler water level alarm prompt; when starting, the conversion switch SA2 is rotated to close the SA2 contact, simulating that the boiler water level is extremely low at this time. The PLC terminal Q0.6 output makes the KA7 relay energized and attracted, and KA7 is connected in series to the boiler operation program loop as a boiler operation protection. When the water level is extremely low, the PLC terminals Q0.0, Q0.2, Q0.3, Q0.4, and the PLC extension module terminal Q.2 outputs disconnect KA1, KA3, KA4, KA5, and HL3 to stop the boiler; when starting, the conversion switch SA3 is rotated to close the SA3 contact, simulating that the boiler water level is high at this time. The PLC terminal Q0.7 output makes the KA8 relay energized and attracted, which serves as a high boiler water level alarm prompt; when starting, the conversion switch SA4 is rotated to close the S The A4 contact is closed, simulating that the boiler water level is extremely high at this time. The PLC terminal Q1.0 output makes the KA9 relay energized and attracted. KA9 is connected in series to the boiler operation program loop as a boiler operation protection. When the water level is extremely high, the PLC terminals Q0.0, Q0.2, Q0.3, Q0.4 and the PLC extension module terminal Q.2 outputs are stopped to disconnect KA1, KA3, KA4, KA5, and HL3, so that the boiler stops running; when starting, the conversion switch SA5 is rotated to close the SA5 contacts, simulating that the gas pressure in the furnace exceeds the limit at this time. The PLC terminal Q1.1 output makes the KA10 relay energized and attracted. KA10 is connected in series to the boiler operation program loop as a boiler operation protection. When the gas pressure in the furnace exceeds the limit, the PLC terminals Q0.0, Q0.2, Q0.3, Q0.4 and the PLC extension module terminal Q.2 outputs are stopped to disconnect KA1, KA3, KA4, KA5, and HL3, so that the boiler stops running.

[0040] Figure 3 is the electrical schematic diagram of this device, and the following is an analysis of the schematic diagram.

[0041] L6 and N are 220V voltage power supplies. L6 is the 220V voltage live wire, which is connected to the upper end of the normally open points of relays KA1, KA2, KA3, KA4, KA5, KA6, KA7, KA8, KA9, and KA10 respectively. N is the 220V voltage neutral wire, which is connected to the indicator lights HL4, HL5, HL6, HL7, HL8, HL9, HL10, HL11, HL12, and HL13 respectively. The lower end of the normally open points of relays KA1, KA2, KA3, KA4, KA5, KA6, KA7, KA8, KA9, and KA10 is connected to the indicator lights HL4, HL5, HL6, HL7, HL8, HL9, HL10, HL11, HL12, and HL13.

[0042] When the normally open point of relay KA1 is closed, the indicator light HL4 lights up, which serves as an indication of boiler operation; when the normally open point of relay KA2 is closed, the indicator light HL5 lights up, which serves as an indication of boiler stop; when the normally open point of relay KA3 is closed, the indicator light HL6 lights up, which serves as an indication of air supply valve opening; when the normally open point of relay KA4 is closed, the indicator light HL7 lights up, which serves as an indication of gas valve opening; when the normally open point of relay KA5 is closed, the indicator light HL8 lights up, which serves as a burner operation indication; when the normally open point of relay KA6 is closed, the indicator light HL9 lights up, which serves as a low water level alarm indication; when the normally open point of relay KA7 is closed, the indicator light HL10 lights up, which serves as an extremely low water level alarm indication; when the normally open point of relay KA8 is closed, the indicator light HL11 lights up, which serves as a high water level alarm indication; when the normally open point of relay KA9 is closed, the indicator light HL12 lights up, which serves as an extremely high water level alarm indication; when the normally open point of relay KA10 is closed, the indicator light HL13 lights up, which serves as an over-limit gas pressure alarm indication.

Claims

1. A gas boiler electrical control simulation device, characterized in that: Including three-phase power supply L1, L2, L3, 3P circuit breaker QFI, inverter, three-phase motor M, PLC, PLC expansion module, 2P circuit breaker QF2, 2P circuit breaker QF3, DC power supply, DC voltage generator; The three-phase power supply L1, L2, L3, 3P circuit breaker QFI, inverter and three-phase motor M are connected in sequence. The input terminals I0.0, I0.1, I0.2, I0.3, I0.4, I0.5 and I0.6 of the PLC are respectively connected to the start button SB1, the stop button SB2, the emergency stop button SB3, the first transfer switch SA1, the second transfer switch SA2, the third transfer switch SA3, the fourth transfer switch SA4 and the fifth transfer switch SA5; The output terminals Q0.0, Q0.1, Q0.2, Q0.3, Q0.4, Q0.5, Q0.6, Q0.7, Q1.0, and Q1.1 of the PLC are connected to relays KA1, KA2, KA3, KA4, KA5, KA6, KA7, KA8, KA9, and KA10 respectively; The output terminals Q.0, Q.1 and Q.2 of the PLC expansion module are connected to the first indicator light HL1, the second indicator light HL2 and the third indicator light HL3 respectively; The three-phase power supply L1 and N line are connected to the upper side of the 2P circuit breaker QF2, and the lower side of the 2P circuit breaker QF2 is connected to the PLC power terminals AC and N. The power terminal AC is short-circuited with the PLC terminals 1L, 2L, 3L and the PLC expansion module 1L terminal as the 220V voltage live wire, and the power terminal N is short-circuited with the relays KA1, KA2, KA3, KA4, KA5, KA6, KA7, KA8, KA9, KA10, HL1, HL2, and HL3 as the 220V voltage neutral line. The PLC terminals M and M1 are short-circuited as the 24V negative voltage, and the PLC terminal L+ is connected with SB1, SB2, SB3, SA1, SA2, SA3, SA4, and SA5 as the 24V positive voltage; The three-phase power supply L2 and the N line are connected to the upper side of the 2P circuit breaker QF3, and the lower side of the 2P circuit breaker QF3 is connected to the DC power supply, DC voltage generator, and the control terminals AI1 and AGDN of the inverter in sequence; The inverter control terminal +24V and DI1 lead wire are connected in series with the KA1 normally open contact; PLC control function: After pressing the start button SB1, the PLC terminal Q0.0 output makes the KA1 relay energized and closed, simulating the start of the boiler; 3 seconds later, the PLC expansion module Q.0 output makes the HL1 indicator light up, simulating the pre-purge of the boiler, and it goes out 30 seconds after lighting up, simulating the completion of the pre-purge; at the same time, the PLC terminals Q0.2, Q0.3 and the PLC expansion module terminal Q.2 output make the KA3 and KA4 relays energized and closed and the HL3 indicator light up, respectively simulating the opening of the air supply valve and the gas supply valve and the normal water level status. These three conditions are used as the burner start conditions. When these three conditions are met at the same time, the PLC terminal Q0.4 output makes the KA5 relay energized and closed 3S later, simulating the start-up and operation of the boiler burner; After pressing the stop button SB2, the output of PLC terminal Q0.1 and PLC extension module terminal Q.1 causes the KA2 relay to be energized and closed, simulating the boiler stop state. The HL2 indicator light turns on for 30 seconds and then turns off, simulating the post-purge of the boiler. At the same time, the output of PLC terminals Q0.0, Q0.2, Q0.3, Q0.4 and PLC extension module terminal Q.2 is stopped, causing KA1, KA3, KA4, KA5, and HL3 to be disconnected, stopping the boiler. When starting, press the emergency stop button SB3 to stop the output of PLC terminals Q0.0, Q0.2, Q0.3, Q0.4, and PLC expansion module terminal Q.2 to disconnect KA1, KA3, KA4, KA5, and HL3, and stop the boiler; When starting, the conversion switch SA1 is rotated to close the SA1 contact, simulating that the boiler water level is low at this time. The PLC terminal Q0.5 output makes the KA6 relay energized and attracted, which serves as a low boiler water level alarm prompt; when starting, the conversion switch SA2 is rotated to close the SA2 contact, simulating that the boiler water level is extremely low at this time. The PLC terminal Q0.6 output makes the KA7 relay energized and attracted, and KA7 is connected in series to the boiler operation program loop as a boiler operation protection. When the water level is extremely low, the PLC terminals Q0.0, Q0.2, Q0.3, Q0.4, and the PLC extension module terminal Q.2 outputs disconnect KA1, KA3, KA4, KA5, and HL3 to stop the boiler; when starting, the conversion switch SA3 is rotated to close the SA3 contact, simulating that the boiler water level is high at this time. The PLC terminal Q0.7 output makes the KA8 relay energized and attracted, which serves as a high boiler water level alarm prompt; when starting, the conversion switch SA4 is rotated to close the S A4 contact is closed, simulating that the boiler water level is extremely high at this time. The output of PLC terminal Q1.0 makes the KA9 relay energized and attracted. KA9 is connected in series to the boiler operation program loop as boiler operation protection. When the water level is extremely high, the output of PLC terminals Q0.0, Q0.2, Q0.3, Q0.4 and PLC extension module terminal Q.2 stops KA1, KA3, KA4, KA5 and HL3, and the boiler stops running. When starting, the conversion switch SA5 is rotated to close the SA5 contact, simulating that the gas pressure in the furnace exceeds the limit at this time. The output of PLC terminal Q1.1 makes the KA10 relay energized and attracted. KA10 is connected in series to the boiler operation program loop as boiler operation protection. When the gas pressure in the furnace exceeds the limit, the output of PLC terminals Q0.0, Q0.2, Q0.3, Q0.4 and PLC extension module terminal Q.2 stops KA1, KA3, KA4, KA5 and HL3, and the boiler stops running. The three-phase power supply L3 and N line are connected to the upper side of the 2P circuit breaker QF4. The terminals L6 and N on the lower side of the 2P circuit breaker QF4 are 220V voltage power supplies. L6 is the 220V voltage live wire, which is respectively connected to the upper ends of the normally open points of relays KA1, KA2, KA3, KA4, KA5, KA6, KA7, KA8, KA9, and KA10. N is the 220V voltage neutral line, which is respectively connected to the indicator lights HL4, HL5, HL6, HL7, HL8, HL9, HL10, HL11, HL12, and HL13. The lower ends of the normally open points of relays KA1, KA2, KA3, KA4, KA5, KA6, KA7, KA8, KA9, and KA10 are connected to the indicator lights HL4, HL5, HL6, HL7, HL8, HL9, HL10, HL11, HL12, and HL13. When the normally open point of relay KA1 is closed, the indicator light HL4 lights up, which serves as an indication of boiler operation; when the normally open point of relay KA2 is closed, the indicator light HL5 lights up, which serves as an indication of boiler stop; when the normally open point of relay KA3 is closed, the indicator light HL6 lights up, which serves as an indication of air supply valve opening; when the normally open point of relay KA4 is closed, the indicator light HL7 lights up, which serves as an indication of gas valve opening; when the normally open point of relay KA5 is closed, the indicator light HL8 lights up, which serves as a burner operation indication; when the normally open point of relay KA6 is closed, the indicator light HL9 lights up, which serves as a low water level alarm indication; when the normally open point of relay KA7 is closed, the indicator light HL10 lights up, which serves as an extremely low water level alarm indication; when the normally open point of relay KA8 is closed, the indicator light HL11 lights up, which serves as a high water level alarm indication; when the normally open point of relay KA9 is closed, the indicator light HL12 lights up, which serves as an extremely high water level alarm indication; when the normally open point of relay KA10 is closed, the indicator light HL13 lights up, which serves as an over-limit gas pressure alarm indication.

2. A gas boiler electrical control simulation device according to claim 1, characterized in that: It also includes a touch screen HMI, and the touch screen HMI and PLC are connected through a network cable. The two components communicate and interconnect to realize touch screen control and operation data feedback.

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