Starting control device for double-motor starting of nuclear safety level diesel engine

Abstract

The invention provides a starting control device for double-motor starting of a nuclear safety level diesel engine. The starting control device comprises a main motor M1, a standby motor M2, an intermediate relay K002, a pulse relay K003, an intermediate relay K004, a main repeated starting relay K01 and an auxiliary repeated starting relay K02. The sequence switching of the main motor and the standby motor can be realized only by repeatedly sending a starting signal by the diesel engine control system; control and time delay are achieved through capacitor discharging, the repeated starting function is achieved, and meanwhile meshing faults of the output gear are avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of diesel engine standby starting, and particularly relates to a starting control device for dual-motor starting of a nuclear safety class diesel engine. Background Art

[0002] Since diesel generator sets are generally standby units, most of them are in a power-off environment during starting, and the operation of peripheral equipment is relatively restricted. To ensure starting reliability, an electric motor is generally driven by a storage battery to drive the diesel engine to reach the firing speed. Because of the high safety level of nuclear safety class diesel engines, more stringent requirements are put forward for the reliable and stable operation of the units. Usually, a redundant starting function is required, that is, after one starting method fails, it can be quickly switched to another starting method for starting to ensure the smooth starting of the diesel generator set for power supply.

[0003] The existing starting control methods for general diesel generator sets have the following deficiencies: 1. The meshing process may fail, and the output pinion may not be correctly and fully meshed with the flywheel. Forced starting may cause the pinion of the motor to be damaged by teeth; 2. To switch between dual motors, a switching control circuit needs to be added to switch to the standby motor for starting when the main motor starting fails. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention provides the following technical solutions:

[0005] A starting control device for dual-motor starting of a nuclear safety class diesel engine, which includes a main motor M1, a standby motor M2, a diesel engine control system, an intermediate relay K002, a pulse relay K003, an intermediate relay K004, a main repeat starting relay K01, and a sub-repeat starting relay K02;

[0006] The positive and negative poles between the diesel engine starting signal input control terminal of the diesel engine control system are connected to the coil of the intermediate relay K002, and the positive and negative poles between the starting device control terminal of the diesel engine control system are connected to the coil of the intermediate relay K004;

[0007] The common contact 30 of the intermediate relay K002 is connected to the normally open contact 87 of the intermediate relay K004, and the normally closed contact 87a of the intermediate relay K002 is left floating;

[0008] The normally open contact 87 of the intermediate relay K002 is respectively connected to the A1 end of the coil of the pulse relay K003, the normally open contact group 1 of the pulse relay K003, and the normally closed contact group 5 of the pulse relay K003. The normally open contact group 2 of the pulse relay K003 is connected to the 50g end of the main repeat starting relay K01, and the normally closed contact group 6 of the pulse relay K003 is connected to the 50g end of the sub-repeat starting relay K02;

[0009] The A2 terminal of the coil of the pulse relay K003 is connected to the negative pole of the battery power supply;

[0010] The common contact 30 of the intermediate relay K004 is connected to the positive pole of the battery power supply in series via the fuse F001; the normally closed contact 87a of the intermediate relay K004 is left floating;

[0011] The positive pole of the battery power supply is also respectively connected to the 30 terminals of the main motor M1 and the standby motor M2;

[0012] The negative pole of the battery power supply is also respectively connected to the 31 terminals of the main motor M1 and the standby motor M2, and the 31 terminals of the main repeat start relay K01 and the secondary repeat start relay K02;

[0013] The 50 terminal of the main motor M1 is connected to the 50h terminal of the main repeat start relay K01;

[0014] The 48 terminal of the main motor M1 is connected to the 48 terminal of the main repeat start relay K01;

[0015] The 50 terminal of the standby motor M2 is connected to the 50h terminal of the secondary repeat start relay K02;

[0016] The 48 terminal of the standby motor M2 is connected to the 48 terminal of the secondary repeat start relay K02.

[0017] Furthermore, the main repeat start relay K01 and the secondary repeat start relay K02 have the same structure and both include two coils: coil LA and coil LB. Each coil controls one contact. Among them, the contact controlled by coil LA is a normally open contact, and the contact controlled by coil LB is a normally closed contact;

[0018] Among them, the 31 terminal is connected to one end of coil LA. The other end of coil LA is respectively electrically connected to one end of coil LB and one end of the normally closed contact. The other end of the normally closed contact of LB is respectively connected to one end of the normally open contact of LA and the 50g terminal. The other end of the normally open contact of LA is connected to the 50h terminal; A capacitor C1 is connected in parallel with coil LB, and the other end of coil LB is connected to the positive pole of diode D1, and the negative pole of diode D1 is connected to the 48 terminal.

[0019] Furthermore, the battery power supply is a 24V battery pack.

[0020] Furthermore, the model of the intermediate relay K002 is CHINT JD2914F.

[0021] Furthermore, the model of the pulse relay K003 is ABB E290-16-11+E292-16-11.

[0022] Furthermore, the model of the intermediate relay K004 is CHINT JD2914F.

[0023] The present invention can achieve the sequential switching of the main and standby motors only by repeatedly sending a starting signal; through capacitor discharge for control and time delay, it realizes the repeated starting function and avoids the meshing failure of the output gear at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0025] Figure 1 Schematic diagram of the circuit structure principle of the present invention;

[0026] Figure 2 Working timing diagram of the starting control device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0028] The output gear of the starting motor generally adopts a rotating meshing method. When the starting motor receives a starting signal, the secondary meshing relay first acts, rotates and extends the output gear to mesh with the flywheel of the diesel engine. When the output gear is meshed in place, the main output relay of the starting motor is turned on, so that the main coil of the starting motor starts to act and output, driving the diesel engine to rotate. When the diesel engine reaches the firing speed, the atomized diesel in the cylinder is compressed and ignited, and the speed rises rapidly. At this time, the starting signal given to the motor is withdrawn, the motor is powered off, and the output gear is retracted by the spring force to disengage from the diesel engine, and the starting process is completed. According to the above starting process, the control circuit of the dual-motor starting control device of the present invention is designed.

[0029] The present invention mainly designs a dual-motor switching circuit, and utilizes the characteristic that the pulse relay maintains its original state after pulse switching to realize the circuit switching of the dual motors.

[0030] The 48-terminal of the starting motor involved in the present invention is at a high potential of 24V when the main coil of the motor outputs normally; when the pinion is not meshed and the main coil of the starting motor is not turned on, it is at a low potential of 0V. The repeated starting of the starting motor can be controlled by detecting the state of terminal 48.

[0031] Such as Figure 1As shown in the figure, a starting control device for a nuclear safety class diesel engine with dual-motor starting includes a main motor M1, a standby motor M2, a diesel engine control system, an intermediate relay K002, a pulse relay K003, an intermediate relay K004, a main repeated starting relay K01, and a secondary repeated starting relay K02;

[0032] The diesel engine control system is responsible for providing a control input signal and a diesel engine starting signal to the starting control device.

[0033] The positive and negative poles of the diesel engine starting signal input control terminal of the diesel engine control system are connected to the coil of the intermediate relay K002 to control the input of the diesel engine starting signal; the positive and negative poles of the circuit power supply control terminal of the diesel engine control system are connected to the coil of the intermediate relay K004 to control the activation of the starting device function.

[0034] The common contact 30 of the intermediate relay K002 is connected to the normally open contact 87 of the intermediate relay K004 to introduce the 24V high potential of the battery, which is used to control the action of the K003 coil and provide the starting control power supply. The normally closed contact 87a of the intermediate relay K002 is left floating.

[0035] The normally open contact 87 of the intermediate relay K002 is respectively connected to the A1 terminal of the coil of the pulse relay K003, the normally open contact group 1 of the pulse relay K003, and the normally closed contact group 5 of the pulse relay K003. The normally open contact group 2 of the pulse relay K003 is connected to the 50g terminal of the main repeated starting relay K01, and the normally closed contact group 6 of the pulse relay K003 is connected to the 50g terminal of the secondary repeated starting relay K02; the power signal connected to the K003 coil is to control the switching of the normally open and normally closed contact groups of the pulse relay when the diesel engine starting signal is input; the signals connected to the normally open and normally closed contact groups are respectively the starting signals for the repeated starting relays K01 and K02, which are used to control the starting motor action.

[0036] The A2 terminal of the coil of the pulse relay K003 is connected to the negative pole of the battery power supply, forming a loop with the A1 connected to the normally open contact 87 of the intermediate relay K002 to achieve the control function;

[0037] The common contact 30 of the intermediate relay K004 is connected to the positive pole of the battery power supply in series through the fuse F001 to input power to the starting action circuit. The normally closed contact 87a of the intermediate relay K004 is left floating.

[0038] The positive pole of the battery power supply is also respectively connected to the 30 terminals of the main motor M1 and the standby motor M2 to provide starting current for the main coil of the starting motor, and is also connected to the common terminal contact 30 of the intermediate relay K004 through the fuse F001 to provide control current for the starting control device.

[0039] The negative pole of the battery power supply is also connected to the 31 terminals of the main motor M1 and the standby motor M2 respectively, the 31 terminals of the main repeated starting relay K01 and the secondary repeated starting relay K02; it provides the negative pole of the circuit for the main coil of the starting motor, and is also connected to the coil terminal A2 of the pulse relay K003 to provide the negative pole of the circuit for the control coil of K003.

[0040] The normally open group of contacts of the pulse relay K003 is connected to the normally open contacts of the relay K002 and the 50g terminal of the repeated starting relay K01 to provide a starting signal for the main starting motor.

[0041] The normally closed group of contacts of the pulse relay K003 is connected to the normally open contacts of the relay K002 and the 50g terminal of the repeated starting relay K02 to provide a starting signal for the standby starting motor.

[0042] The 50 terminal of the main motor M1 is connected to the 50h terminal of the main repeated starting relay K01 to receive the starting command signal of the starting control system.

[0043] The 48 terminal of the main motor M1 is connected to the 48 terminal of the main repeated starting relay K01 to feedback the state of the M1 motor and control the main repeated starting relay K01 to realize the repeated starting function.

[0044] The 50 terminal of the standby motor M2 is connected to the 50h terminal of the secondary repeated starting relay K02 to receive the starting command signal of the starting control system.

[0045] The 48 terminal of the standby motor M2 is connected to the 48 terminal of the secondary repeated starting relay K02 to feedback the state of the M2 motor and control the secondary repeated starting relay K02 to realize the repeated starting function.

[0046] The circuit of the present invention includes two repeated starting relays for repeated starting: the main repeated starting relay K01 and the secondary repeated starting relay K02. The two repeated starting relays have the same structure. Taking Figure 1 the main repeated starting relay K01 in [] as an example: the repeated starting relay has four ports: 50h terminal, 48 terminal, 31 terminal and 50g terminal, two coils: coil LA and coil LB, each coil controls one contact, wherein, the contact controlled by coil LA is a normally open contact, and the contact controlled by coil LB is a normally closed contact; 1 charge and discharge capacitor C1 and 1 protection diode.

[0047] Among them, the 31 terminal is connected to one end of the coil LA, the other end of the coil LA is electrically connected to one end of the coil LB and one end of the normally closed contact respectively, the other end of the normally closed contact is connected to one end of the normally open contact and the 50g terminal respectively, and the other end of the normally open contact is connected to the 50h terminal; the coil LB is connected in parallel with the capacitor C1, and the other end of the coil LB is connected to the positive pole of the diode D1, and the negative pole of the diode D1 is connected to the 48 terminal.

[0048] The present invention mainly controls the charge and discharge time by selecting the appropriate capacitance of the C1 capacitor in the repeated starting relay, so as to achieve the repeated starting of the same motor within the time when the control system outputs the starting signal. If the starting is not successful within the specified time, the control system disconnects the starting signal, delays, and outputs the starting signal repeatedly. At this time, the starting control device automatically switches to the standby motor for starting.

[0049] Furthermore, the battery power supply is a 24V battery pack.

[0050] Furthermore, the model of the intermediate relay K002 is CHINT JD2914F.

[0051] Furthermore, the model of the pulse relay K003 is ABB E290-16-11+E292-16-11.

[0052] Furthermore, the model of the intermediate relay K004 is CHINT JD2914F.

[0053] Working principle:

[0054] Regarding the main and standby motor switching: The present invention makes full use of the functional characteristics of the pulse relay K003 for switching; specifically, first, the diesel engine control system detects whether the current diesel engine is in a starting state. When there is no alarm or fault affecting the start, the diesel engine control system outputs a control signal to the starting device. At this time, the intermediate relay K004 operates (the common contact 30 of K004 is connected to the normally open contact 87); when the diesel engine control system starts the diesel engine and inputs the diesel engine starting signal, the intermediate relay K002 operates (its common contact 30 is connected to the normally open contact 87); the coil A1 terminal of the pulse relay K003 is powered through the normally open contact 87 of K002. At this time, the coil operates, and the normally open contact groups 1 and 2 of the pulse relay K003 are switched to the closed state, connecting the control circuit of the main motor M1, and the normally closed contact groups 5 and 6 of the pulse relay K003 are switched to the open state, disconnecting the control circuit of the standby motor M2. When the input delay time of the starting signal control arrives and the diesel engine still fails to start, the diesel engine control system disconnects the starting signal output. At this time, the coil of the intermediate relay K002 is de-energized, and the common contact 30 of the intermediate relay K002 disconnects the connection with the normally open contact 87 and is switched to the connection with the normally closed contact 87a; the pulse relay K003 is de-energized, and the state of its contact group remains unchanged. When the diesel engine control system issues the starting signal again, the intermediate relay K002 operates. At this time, the normally closed contact groups 5 and 6 of the pulse relay K003 are switched to the closed state, connecting the control circuit of the standby motor M2, and the normally open contact groups 1 and 2 are switched to the open state, disconnecting the main motor control circuit, thus realizing the automatic switching of the main and standby starting motors.

[0055] Regarding the repeated starting function: The present invention makes full use of the output state change characteristics of the detection terminal of the starting motor, namely terminal 48, for whether the engagement is in place: when the output gear of the motor is engaged in place, the output of terminal 48 is 24V+; when the gear is not engaged in place, the output of terminal 48 is always negative. Specifically, the signal input control terminal of the diesel engine control system sends a starting signal to the intermediate relay K002 to make it turn on. The pulse relay K003 is connected through terminal 50g, and the coil LA in the repeated starting relay is energized to act (the normally open contact it controls closes). The 24V power supply + is input to terminal 50h, and the motor starts to work. When the output gear is engaged in place, terminal 48 is 24V+, and at this time, the coil LB cannot act, and the starting voltage is continuously input to terminal 50h, and the motor works smoothly. When the output gear is not engaged in place, terminal 48 is negative, the voltage of the positive electrode of the capacitor C1 rises, forming an electric potential difference with terminal 48. At this time, the diode D1 is turned on, the capacitor discharges, the coil LB acts (the normally closed contact it controls opens), disconnects the power supply of the coil LA, and the normally open contact controlled by the coil LA resets and disconnects. At this time, there is no power input to terminal 50h connected to terminal 50 of the starting motor, and the starting motor does not work. Under the action of the spring force, the output gear retracts and resets. When the capacitor C1 finishes discharging (about 2S), the normally closed contact controlled by the coil LB resets and closes. At this time, the coil LA is connected to the 24V power supply at terminal 50g again, the coil LA acts, the normally open contact closes, and the 24V power supply is connected to terminal 50h, that is, terminal 50 of the starting motor, and the starting motor performs the next round of work, which realizes the repeated starting function.

[0056] As Figure 2 shown in the timing diagram of the starting process embodiment controlled by the present invention:

[0057] 1. During the first starting signal input cycle, the main motor cannot start normally. The main repeated starting relay K01 repeats starting three times and reaches the starting signal delay. At this time, the starting signal is cancelled;

[0058] 2. After the control system delays and inputs the starting signal again, at this time, the starting device has switched the starting circuit to the standby motor. At this time, the secondary repeated starting relay K02 acts, and the standby motor is normally engaged and outputs to drive the diesel engine speed to reach 300r / m. At this time, the control system monitors that the diesel engine speed reaches the normal starting success speed and cancels the output of the starting signal.

[0059] The present invention has the function of realizing repeated meshing and starting when the pinion gear is not meshed, and can automatically switch the starting control of the main and standby redundant motors.

[0060] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A starting control device for a nuclear safety-grade diesel engine with dual motors, characterized in that: It includes a main motor M1, a standby motor M2, a diesel engine control system, an intermediate relay K002, a pulse relay K003, an intermediate relay K004, a main repeated starting relay K01 and a secondary repeated starting relay K02; The coil of the intermediate relay K002 is connected between the positive and negative poles of the diesel engine start signal input control terminal of the diesel engine control system, and the coil of the intermediate relay K004 is connected between the positive and negative poles of the starter control terminal of the diesel engine control system; The common contact 30 of the intermediate relay K002 is connected to the normally open contact 87 of the intermediate relay K004, and the normally closed contact 87a of the intermediate relay K002 is suspended; The normally open contact 87 of the intermediate relay K002 is respectively connected to the A1 end of the coil of the pulse relay K003, the normally open group contact 1 end of the pulse relay K003, and the normally closed group contact 5 end of the pulse relay K003, the normally open group contact 2 end of the pulse relay K003 is connected to the 50g end of the main repeated start relay K01, and the normally closed group contact 6 end of the pulse relay K003 is connected to the 50g end of the auxiliary repeated start relay K02; The A2 end of the pulse relay K003 coil is connected to the negative pole of the battery power supply, and forms a loop with A1 connected to the normally open contact 87 of the intermediate relay K002 to realize the control function; The common contact 30 of the intermediate relay K004 is connected to the positive pole of the battery power supply through the fuse F001; the normally closed contact 87a of the intermediate relay K004 is suspended; The positive electrode of the battery power source is also connected to the 30 terminals of the main motor M1 and the standby motor M2 respectively; The negative electrode of the battery power source is also connected to the terminals 31 of the main motor M1 and the standby motor M2, the main re-starting relay K01 and the auxiliary re-starting relay K02; Terminal 50 of the main motor M1 is connected to terminal 50h of the main repeated starting relay K01; Terminal 48 of the main motor M1 is connected to terminal 48 of the main repeated starting relay K01; The terminal 50 of the standby motor M2 is connected to the terminal 50h of the auxiliary repeated starting relay K02; The terminal 48 of the standby motor M2 is connected to the terminal 48 of the auxiliary restart relay K02.

2. A starting control device for dual-motor starting of a nuclear safety-grade diesel engine as claimed in claim 1, characterized in that: The main repetitive start relay K01 and the auxiliary repetitive start relay K02 have the same structure, both of which include two coils: coil LA and coil LB, each coil controls a contact, wherein coil LA controls a normally open contact, and coil LB controls a normally closed contact; Among them, terminal 31 is connected to one end of coil LA, the other end of coil LA is electrically connected to one end of coil LB and one end of the normally closed contact, the other end of the normally closed contact of LB is respectively connected to one end of the normally open contact of LA and terminal 50g, and the other end of the normally open contact of LA is connected to terminal 50h; coil LB is connected in parallel with capacitor C1, and the other end of coil LB is connected to the positive electrode of diode D1, and the negative electrode of diode D1 is connected to terminal 48.

3. A starting control device for dual-motor starting of a nuclear safety-grade diesel engine as claimed in claim 1, characterized in that: The battery power source is a 24V battery pack.

4. A starting control device for dual-motor starting of a nuclear safety-grade diesel engine as claimed in claim 1, characterized in that: The model of the intermediate relay K002 is Chint JD2914F.

5. A starting control device for dual-motor starting of a nuclear safety-grade diesel engine as claimed in claim 1, characterized in that: The model of the pulse relay K003 is ABB E290-16-11+E292-16-11.

6. A starting control device for dual-motor starting of a nuclear safety-grade diesel engine as claimed in claim 1, characterized in that: The model of the intermediate relay K004 is Chint JD2914F.

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