Coal Chemical Liquid Oxygen Pump Motor Automatic Control System

Abstract

The utility model belongs to the technical field of coal chemical production electrical system, and specifically relates to a coal chemical liquid oxygen pump motor automatic control system, including a main circuit, a control circuit and a DC power supply unit; main circuit: No. 1 oxygen pump motor is connected to the three-phase power supply through No. 1 inverter and three-phase circuit breaker QF1, and No. 2 oxygen pump motor is connected to the three-phase power supply through No. 2 inverter and three-phase circuit breaker QF2; control circuit: DCS system is adopted, and the DCS system is connected to No. 1 inverter and No. 2 inverter. DC power supply unit: the incoming line side of the two-phase circuit breakers QF3 and QF4 is respectively connected to the 220v power supply, and the outgoing line side is connected to the charging unit, the charging unit is connected to the energy storage unit, and the outgoing line side of the energy storage unit is connected to the intelligent control module, and the output side of the intelligent control module is respectively connected to No. 1 and No. 2 inverters. The utility model realizes the anti-sway and power-off protection of the oxygen pump motor through the DC power supply unit, and realizes the interlocking, mutual standby and protection functions of the oxygen pump motor through DCS, so as to ensure the safe and efficient operation of the oxygen pump motor.

Description

Technical Field

[0001] The utility model belongs to the technical field of coal chemical production electrical systems, and in particular relates to an automatic control system for a coal chemical liquid oxygen pump motor. Background Art

[0002] Coal chemical industry refers to the process of using coal as raw material and converting it into gas, liquid and solid fuels and chemicals through high temperature, high pressure and other chemical processing. It mainly includes coal gasification, liquefaction, dry distillation, tar processing and calcium carbide acetylene chemical industry, so as to convert coal into various fuels and chemical products. It is widely used in people's daily production and life. With the continuous development of coal chemical industry, the stable operation of some devices and equipment of large coal chemical production enterprises has been promoted to the first position. Air separation unit is the basis of coal chemical operation. The oxygen and nitrogen required for coal chemical production come from air separation unit. The oxygen required for the combustion of pulverized coal in the gasifier, the core equipment of coal chemical industry, comes from the air separation unit. In this production process, the oxygen pump motor of the air separation unit will always run stably at about 3185r / min, and the external oxygen supply pressure is 4.75MPa. Once the operation of the oxygen pump motor changes suddenly, such as power shaking, voltage drop, etc., it will cause the gasifier to stop or reduce the load. However, in coal chemical production, the traditional oxygen pump motor control method will not be able to avoid this sudden accident, which will greatly increase the production cost of the enterprise. Therefore, it is very important to provide a safe and reliable oxygen pump motor automatic control system. Summary of the invention

[0003] The utility model aims to solve the problem of interruption of oxygen pump motor operation or abnormal fluctuation of external oxygen supply pressure caused by abnormal circumstances, and proposes an automatic control system for coal chemical liquid oxygen pump motor. The anti-swing and power-off protection of the oxygen pump motor is realized through a DC power supply unit, and the interlocking, mutual backup and protection functions of the oxygen pump motor are realized through DCS to ensure the safe and efficient operation of the oxygen pump motor.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] The utility model provides a coal chemical liquid oxygen pump motor automatic control system, including a main circuit, a control circuit and a DC power supply unit;

[0006] The main circuit includes a three-phase circuit breaker QF1, a three-phase circuit breaker QF2, a No. 1 frequency converter, a No. 2 frequency converter, a No. 1 oxygen pump motor and a No. 2 oxygen pump motor. The No. 1 oxygen pump motor is connected to a three-phase power supply through the No. 1 frequency converter and the three-phase circuit breaker QF1. The No. 2 oxygen pump motor is connected to a three-phase power supply through the No. 2 frequency converter and the three-phase circuit breaker QF2. The No. 1 oxygen pump motor and the No. 2 oxygen pump motor are standby for each other.

[0007] The control circuit adopts a DCS system, which is connected to the No. 1 inverter and the No. 2 inverter. The DCS system controls the start and stop of the inverter and the frequency modulation of the inverter. The inverter feeds back the speed signal, current signal and operation signal to the DCS system;

[0008] A DC power supply unit includes a two-phase circuit breaker QF3, a two-phase circuit breaker QF4, a charging unit, an energy storage unit and an intelligent control unit. The inlet sides of the two-phase circuit breaker QF3 and the two-phase circuit breaker QF4 are respectively connected to a 220V power supply, and the outlet sides are both connected to the charging unit. The charging unit is connected to the energy storage unit, and the output side of the energy storage unit is connected to an intelligent control module. The output side of the intelligent control module is connected to a DC power supply terminal of inverter No. 1 on one side and to a DC power supply terminal of inverter No. 2 on the other side.

[0009] According to the utility model coal chemical liquid oxygen pump motor automatic control system, further, the voltage acquisition terminal of the intelligent control module is connected to the outgoing line side of the three-phase circuit breaker QF1 and the three-phase circuit breaker QF2 through a cable.

[0010] According to the utility model coal chemical liquid oxygen pump motor automatic control system, further, the intelligent control module is connected to output module 1 and output module 2 respectively, connected to the DC power terminal of inverter No. 1 through output module 1, and connected to the DC power terminal of inverter No. 2 through module 2.

[0011] According to the utility model coal chemical liquid oxygen pump motor automatic control system, further, in the DCS system, the bearing temperature L of oxygen pump No. 1 is inverted with the operating signal of oxygen pump No. 1 to form an "AND" logic; the operating signal of oxygen pump No. 1 is inverted with the post-pump pressure of oxygen pump No. 1 and the operating current of oxygen pump No. 1 to form a "three-out-of-two" logic, and then with the protection of oxygen pump No. 1 to form an "AND" logic; the manual stop of oxygen pump No. 1 on the panel, the bearing temperature HH of oxygen pump No. 1, the sealing gas temperature LL of oxygen pump No. 1, the air compressor failure and the above two "AND" logics together form an "OR" logic, which will trigger the No. 1 frequency converter to stop running.

[0012] According to the utility model coal chemical liquid oxygen pump motor automatic control system, further, in the DCS system, the bearing temperature L of oxygen pump No. 2 is inverted with the operating signal of oxygen pump No. 2 to form an "AND" logic; the operating signal of oxygen pump No. 2 is inverted with the pressure after the pump and the operating current of oxygen pump No. 2 to form a "three-out-of-two" logic, and then with the protection of oxygen pump No. 2 to form an "AND" logic; the manual stop of oxygen pump No. 2 on the panel, the bearing temperature HH of oxygen pump No. 2, the sealing gas temperature LL of oxygen pump No. 2, the air compressor failure and the above two "AND" logics together form an "OR" logic, which will trigger the No. 2 frequency converter to stop running.

[0013] According to the utility model coal chemical liquid oxygen pump motor automatic control system, further, the panel manually starts the No. 1 oxygen pump, the panel manually stops the No. 1 oxygen pump, the panel manually starts the No. 2 oxygen pump, and the panel manually stops the No. 2 oxygen pump, which are all 3s pulse signals.

[0014] Compared with the prior art, the utility model has the following advantages:

[0015] The utility model coal chemical liquid oxygen pump motor automatic control system perfectly solves the impact of grid voltage drop and short-term power outage on oxygen pump motor in continuous production by adding a DC power supply unit. When encountering grid shaking and short-term power outage, the energy storage unit is used to continuously supply power to the oxygen pump motor. After the grid returns to normal, the oxygen pump motor can automatically switch to the grid operation. During the whole process, the oxygen pump motor and the frequency converter continuously output stable power without speed drop, power fluctuation, flash and restart. The oxygen pump output load is truly undisturbed, which greatly reduces the production cost of the enterprise and effectively improves the economic benefits of the enterprise. In addition, the No. 1 oxygen pump motor and the No. 2 oxygen pump motor are backup for each other, so that the two oxygen pump motors can switch freely in abnormal situations without reducing the external oxygen supply pressure, so that the production can be carried out continuously and stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the automatic control system of the coal chemical liquid oxygen pump motor of the utility model embodiment;

[0017] Figure 2 This is a principle block diagram of the automatic control system of the coal chemical liquid oxygen pump motor of the utility model embodiment;

[0018] Figure 3 This is the control principle of the DCS of the embodiment of the utility model when oxygen pump No. 1 is used as the main pump and oxygen pump No. 2 is used as the backup pump;

[0019] Figure 4 This is the control principle when the No. 2 oxygen pump in the DCS of the embodiment of the utility model is used as the main pump and the No. 1 oxygen pump is used as the standby pump. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0021] like Figure 1 As shown, the coal chemical liquid oxygen pump motor automatic control system of this embodiment includes a main circuit, a control circuit and a DC power supply unit.

[0022] like Figure 2As shown, the main circuit includes three-phase circuit breaker QF1, three-phase circuit breaker QF2, frequency converter No. 1, frequency converter No. 2, oxygen pump motor No. 1 and oxygen pump motor No. 2. Oxygen pump motor No. 1 is connected to section I three-phase power supply through frequency converter No. 1 and three-phase circuit breaker QF1, and oxygen pump motor No. 2 is connected to section II three-phase power supply through frequency converter No. 2 and three-phase circuit breaker QF2. Oxygen pump motor No. 1 and oxygen pump motor No. 2 are standby for each other. Preferably, three-phase circuit breakers QF1 and QF2 use withdrawable frame circuit breakers of model E1B63TLSI, and frequency converters No. 1 and No. 2 use ACS800-07-0400-3+E210+E208+E205+B054+2L505+P901+R712.

[0023] like Figure 2 As shown, the control circuit adopts a DCS system, and the DCS system is connected to the No. 1 inverter and the No. 2 inverter. The DCS system controls the start and stop of the inverter and the frequency modulation of the inverter. The inverter feeds back the speed signal, current signal and operation signal to the DCS system. Specifically, the DCS control output terminal is connected to the start and stop input terminal of the No. 1 inverter, and the DCS sends the No. 1 inverter DCS start and stop command to the No. 1 inverter to realize the start and stop of the No. 1 inverter. The DCS frequency control terminal is connected to the frequency input terminal of the No. 1 inverter, and the DCS sends the No. 1 inverter DCS frequency setting command to the No. 1 inverter to realize the frequency modulation of the No. 1 inverter. The DCS input terminal is connected to the speed signal output terminal of the No. 1 inverter to realize the output of the speed signal of the No. 1 inverter. The DCS input terminal is connected to the running current output terminal of the No. 1 inverter to realize the output of the current signal of the No. 1 inverter. The DCS input terminal is connected to the running feedback terminal of the No. 1 inverter to realize the output of the running signal of the No. 1 inverter. Similarly, the DCS control output terminal is connected to the start / stop input terminal of inverter No. 2; the DCS frequency control terminal is connected to the frequency input terminal of inverter No. 2; the DCS input terminal is connected to the speed signal output terminal of inverter No. 2; the DCS input terminal is connected to the running current output terminal of inverter No. 2; and the DCS input terminal is connected to the running feedback terminal of inverter No. 2. Furthermore, the interlocking mutual standby command of inverter No. 1 and inverter No. 2 comes from DCS. The interlocking stop command of inverter No. 1 and inverter No. 2 comes from the DCS interlocking program and triggers the inverter stop command.

[0024] Preferably, all control cables and signal cables are ZR-DJYPVP-2×2×2.5 computer cables.

[0025] like Figure 2As shown, the DC power supply unit includes a two-phase circuit breaker QF3, a two-phase circuit breaker QF4, a charging unit, an energy storage unit, an intelligent control unit, an output module 1 and an output module 2. The inlet side of the two-phase circuit breaker QF3 and the two-phase circuit breaker QF4 are respectively connected to the section I power supply and the section II power supply, and the outlet side is connected to the charging unit to provide 220v voltage for the charging unit. The charging unit is connected to the energy storage unit, and the energy storage unit is charged daily by the charging unit. The output side of the energy storage unit is connected to the intelligent control module, and the two outputs of the intelligent control module are respectively connected to the output module 1 and the output module 2. The outlet side of the output module 1 is connected to the DC terminal busbar of the No. 1 inverter, and the outlet side of the output module 2 is connected to the DC terminal busbar of the No. 2 inverter. The voltage acquisition terminal of the intelligent control module is connected to the outlet side of the three-phase circuit breaker QF1 and the three-phase circuit breaker QF2 through a cable, which is used to monitor the voltage changes of the three-phase power supply of section I and the three-phase power supply of section II in real time.

[0026] Preferably, the energy storage unit has a capacity of 350KW and an anti-shaking time of 10s. The energy storage unit can use a lithium battery. The charging unit uses a charging management chip (CN3791 chip can be used). The intelligent control module uses a single-chip microcomputer, and output module 1 and output module 2 use relays as switches.

[0027] The interlocking logic design in the DCS system is as follows:

[0028] like Figure 3 As shown, the bearing temperature L of oxygen pump No. 1 will be delayed for 2s and the operation signal of oxygen pump No. 1 will be inverted to form the logic of "AND". When the logic of "AND" is established, inverter No. 1 will be triggered to stop running and inverter No. 2 will be automatically triggered to work at full speed.

[0029] After the No. 1 oxygen pump operation signal is inverted, it forms a "three-out-of-two" logic with the No. 1 oxygen pump post-pump pressure and the No. 1 oxygen pump operation current, and then forms an "AND" logic with the No. 1 oxygen pump protection. Specifically, after the No. 1 oxygen pump post-pump pressure, the No. 1 oxygen pump operation current, and the No. 1 oxygen pump operation signal are inverted, two of the three conditions are met at the same time, and after the No. 1 oxygen pump protection interlock, the "AND" logic will be executed, which will trigger the No. 1 inverter to stop running and automatically trigger the No. 2 inverter to work at full speed.

[0030] Manual stop of oxygen pump No. 1 on the panel, bearing temperature HH of oxygen pump No. 1, sealing gas temperature LL of oxygen pump No. 1, and air compressor failure will be delayed for 1s and form an "or" logic with the two aforementioned "and" logics, which will trigger inverter No. 1 to stop running and automatically trigger inverter No. 2 to work at full speed. For fault signals with less harm, it is necessary to delay for several seconds for further judgment to prevent the oxygen pump motor from malfunctioning.

[0031] When the operator clicks to start oxygen pump No. 1 and stop oxygen pump No. 1, preferably, the DCS should send a 3s pulse signal.

[0032] Similarly, if Figure 4 As shown, for the interlocking stop control of inverter No. 2, refer to the interlocking stop control content for inverter No. 1 above.

[0033] Here’s how it works:

[0034] 1. QF1 and QF2 are closed, and inverter No. 1 and inverter No. 2 are energized. At this time, the operator can start and stop the two inverters at will through the DCS system.

[0035] 2. During normal operation, when the operator selects oxygen pump No. 1 as the main pump and oxygen pump No. 2 as the standby pump, it is necessary to click the protection function of oxygen pump No. 1, and then click the DCS start of oxygen pump No. 1. At this time, inverter No. 1 officially starts to work. Since the speed output is zero, the motor of oxygen pump No. 1 will not rotate. When the operator gives any frequency, the motor of oxygen pump No. 1 starts to rotate. For the safety of the operation of the oxygen pump motor, the operator needs to gradually increase the speed of the oxygen pump and reach the speed required for normal operation. (Conversely, oxygen pump No. 2 can also be selected as the main pump and the protection function of oxygen pump No. 2 can be clicked).

[0036] 3. When the main pump is running normally (about 3185r / min), preferably, in order to ensure the absolute stability of production conditions, the backup pump will also be put into operation and controlled at a speed of about 1500r / min.

[0037] 4. After oxygen pump No. 1 and oxygen pump No. 2 are both running, either QF3 or QF4 can be closed (QF3 and QF4 cannot be closed at the same time).

[0038] 5. When QF3 or QF4 is closed, the charging unit is powered and starts to charge the energy storage unit. At the same time, the intelligent control module starts to work and monitors the voltage on the lower side of QF1 and QF2 in real time. When the system voltage fluctuates and meets the requirements set by the intelligent control module, the energy storage unit can automatically supply power to inverter No. 1 or inverter No. 2 through output module 1 or output module 2 for a short time to ensure that the entire system can resist power grid shaking failure. Preferably, the capacity of the energy storage unit should be able to ensure that the oxygen pump can operate for 10S.

[0039] 6. When the bearing temperature HH of oxygen pump No. 1 reaches 115°, DCS triggers oxygen pump No. 1 to stop running and oxygen pump No. 2 to run at full speed. When the sealing gas temperature LL of oxygen pump No. 1 reaches -120°, DCS triggers oxygen pump No. 1 to stop running and oxygen pump No. 2 to run at full speed. When the bearing temperature L of oxygen pump No. 1 reaches -10° and delays for 2S, and the running signal of oxygen pump No. 1 disappears, DCS triggers oxygen pump No. 1 to stop running and oxygen pump No. 2 to run at full speed. When the air compressor fault signal is received, after a delay of 1s, DCS triggers oxygen pump No. 1 to stop running and oxygen pump No. 2 to run at full speed. When the running signal of oxygen pump No. 1 disappears, the outlet pressure of oxygen pump No. 1 is lower than 4.5MPa, and the running current of oxygen pump No. 1 disappears, after two out of three are met and oxygen pump No. 1 is protected, DCS triggers oxygen pump No. 1 to stop running and oxygen pump No. 2 to run at full speed.

[0040] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons with ordinary skills in the field to which the utility model belongs. The words "one" or "an" and the like used in the specification and claims of this application do not necessarily indicate a quantitative limitation. The words "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but do not exclude other elements or objects.

[0041] Finally, it should be noted that the above is only a preferred embodiment of the utility model, which is only used to illustrate the technical solution of the utility model, and is not used to limit the protection scope of the utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model are included in the protection scope of the utility model.

Claims

1. A coal chemical liquid oxygen pump motor automatic control system, characterized in that: It includes a main circuit, a control circuit and a DC power supply unit; The main circuit includes a three-phase circuit breaker QF1, a three-phase circuit breaker QF2, a No. 1 frequency converter, a No. 2 frequency converter, a No. 1 oxygen pump motor and a No. 2 oxygen pump motor. The No. 1 oxygen pump motor is connected to a three-phase power supply through the No. 1 frequency converter and the three-phase circuit breaker QF1. The No. 2 oxygen pump motor is connected to a three-phase power supply through the No. 2 frequency converter and the three-phase circuit breaker QF2. The No. 1 oxygen pump motor and the No. 2 oxygen pump motor are standby for each other. The control circuit adopts a DCS system, which is connected to the No. 1 inverter and the No. 2 inverter. The DCS system controls the start and stop of the inverter and the frequency modulation of the inverter. The inverter feeds back the speed signal, current signal and operation signal to the DCS system; A DC power supply unit includes a two-phase circuit breaker QF3, a two-phase circuit breaker QF4, a charging unit, an energy storage unit and an intelligent control unit. The inlet sides of the two-phase circuit breaker QF3 and the two-phase circuit breaker QF4 are respectively connected to a 220V power supply, and the outlet sides are both connected to the charging unit. The charging unit is connected to the energy storage unit, and the output side of the energy storage unit is connected to an intelligent control module. The output side of the intelligent control module is connected to a DC power supply terminal of inverter No. 1 on one side and to a DC power supply terminal of inverter No. 2 on the other side.

2. The coal chemical liquid oxygen pump motor automatic control system according to claim 1 is characterized in that: The voltage collection terminal of the intelligent control module is connected to the outgoing line side of the three-phase circuit breaker QF1 and the three-phase circuit breaker QF2 through a cable.

3. The coal chemical liquid oxygen pump motor automatic control system according to claim 1 is characterized in that: The intelligent control module is connected to output module 1 and output module 2 respectively, connected to the DC power supply terminal of inverter No. 1 through output module 1, and connected to the DC power supply terminal of inverter No. 2 through module 2.

4. The coal chemical liquid oxygen pump motor automatic control system according to claim 1 is characterized in that: In the DCS system, the bearing temperature L of oxygen pump No. 1 and the inverted running signal of oxygen pump No. 1 form an "AND" logic; the inverted running signal of oxygen pump No. 1, the pressure after pumping of oxygen pump No. 1 and the running current of oxygen pump No. 1 form a "two out of three" logic, and then form an "AND" logic with the protection of oxygen pump No. 1; the manual stop of oxygen pump No. 1 on the panel, the bearing temperature HH of oxygen pump No. 1, the sealing gas temperature LL of oxygen pump No. 1, the air compressor fault and the above two "AND" logics together form an "OR" logic, which will trigger the No. 1 inverter to stop running.

5. The coal chemical liquid oxygen pump motor automatic control system according to claim 4 is characterized in that: In the DCS system, the bearing temperature L of oxygen pump No. 2 is inverted with the running signal of oxygen pump No. 2 to form an "AND" logic; the running signal of oxygen pump No. 2 is inverted with the pressure after pumping and the running current of oxygen pump No. 2 to form a "two out of three" logic, and then with the protection of oxygen pump No. 2 to form an "AND" logic; the manual stop of oxygen pump No. 2 on the panel, the bearing temperature HH of oxygen pump No. 2, the sealing gas temperature LL of oxygen pump No. 2, the air compressor fault and the above two "AND" logics together form an "OR" logic, which will trigger the No. 2 inverter to stop running.

6. The coal chemical liquid oxygen pump motor automatic control system according to claim 5, characterized in that: Manual start of oxygen pump No. 1 on the panel, manual stop of oxygen pump No. 1 on the panel, manual start of oxygen pump No. 2 on the panel, and manual stop of oxygen pump No. 2 on the panel are all 3s pulse signals.

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