CN211202070U

CN211202070U - Lubricating oil supply system allowing DC accident oil pump motor to be started slowly

Info

Publication number: CN211202070U
Application number: CN201922199516.4U
Authority: CN
Inventors: 张楠; 李�和
Original assignee: North China Power Engineering Co Ltd of China Power Engineering Consulting Group
Current assignee: North China Power Engineering Co Ltd of China Power Engineering Consulting Group; North China Power Engineering Beijing Co Ltd
Priority date: 2019-12-10
Filing date: 2019-12-10
Publication date: 2020-08-07
Anticipated expiration: 2029-12-10

Abstract

The utility model relates to a lubricating oil supply system allowing the slow start of a direct current accident oil pump motor, which comprises an accident oil pump module driven by a direct current motor to run, wherein the outlet of the accident oil pump module is connected with the lubricating oil outlet of the lubricating oil supply system, and also comprises a main oil pump module which is connected with an alternating current power supply, a rectifier is arranged behind the alternating current power supply, 2 parallel branches are arranged at the outlet of the rectifier, an inverter and an alternating current variable frequency motor are sequentially arranged on each branch, 2 alternating current variable frequency motors are respectively connected with 2 main oil pumps, 2 lubricating oil pipelines where the 2 main oil pumps are positioned are connected with the lubricating oil outlet after being converged, and a first storage battery is also arranged at the outlet of the rectifier. The cost and the failure probability are reduced, the running time of the generator set is increased, and obvious economic benefits and social benefits are achieved.

Description

Lubricating oil supply system allowing DC accident oil pump motor to be started slowly

Technical Field

The utility model discloses be applied to lubricating oil supply system, the sealed oil system of hydrogen of main rotating machinery in thermal power factory (including coal-fired thermal power factory, gas thermal power factory and gas-turbine power factory etc.), also can be used to fields such as oil system in the phase modifier of transformer substation.

Background

At present, lubricating oil supply systems of generator sets in thermal power plants mainly comprise two systems:

the system 1: when starting, 1 start/stop oil pump driven by an alternating current asynchronous motor, a coaxial main oil pump of a main machine large shaft and 1 accident oil pump driven by a direct current motor are adopted;

and (3) system 2: the emergency oil pump is driven by 2 main oil pumps which are driven by alternating current asynchronous motors to start/stop and work and 1 direct current motor.

The main features of the system 1 are: the oil pump driven by the AC asynchronous motor is used during starting and stopping, the coaxial main oil pump installed on the shaft head of the high-pressure cylinder of the steam turbine is used for supplying oil during normal operation, and the accident oil pump driven by the DC motor is started for supplying oil during accidents. Because the shafting of generating set quality is very big, therefore inertia is very big, and when the accident happens, only rely on its inertia to descend to not satisfying the fuel feeding condition from rated speed and take 1 minute or more. Therefore, such systems do not require a fast start-up time for dc motor driven emergency oil pumps.

System 2 is very different from system 1. In the normal start/stop operation, the oil pump driven by the ac asynchronous motor is used as the start oil pump and the stop oil pump, as in the system 1, but in the normal operation of the generator set, the oil pump driven by the ac asynchronous motor is still used as the working oil pump. In case of accident, because the inertia of the ac asynchronous motor and its driven oil pump is very small, the ac asynchronous motor will not provide enough lubricating oil quickly once it is de-energized, and for this reason, the accident oil pump driven by the dc motor must be started at a quick speed to ensure that the supply of lubricating oil is not interrupted, so as to prevent the shafting of the generator set from being damaged.

Only one method is to accelerate the starting speed of the dc motor: the starting current is increased. This can be achieved by reducing the starting resistance.

The starting of the DC motor in the above two systems is realized by connecting a starting resistor in series in an armature loop of the DC motor. Typically 1 in series. The system 1 is only used when the requirements on the starting speed and the starting time are not strict, so that the resistance value of the used starting resistor is larger, and the starting current is relatively smaller; in the system 2, the requirement on the starting speed is high, and the requirement on the starting time is short, so that the resistance value of the starting resistor connected in series is small, but the starting current is large.

When the starting current of the dc motor is large, high requirements are imposed on a dc power supply system, the capacity of the battery, and the connection cable.

The lubricating oil system of system 2 is very critical in terms of the start-up time of the emergency oil pump driven by the dc motor, and therefore has a high risk of running. However, for combustion engines and certain power plants, only the system 2 with the higher risk can be used for reasons of system design.

SUMMERY OF THE UTILITY MODEL

The utility model provides a technical problem be providing one kind to generating set among the thermal power factory (including coal-fired thermal power factory, gas thermal power factory and gas-turbine power factory etc.) allow lubricating oil feeding system of direct current accident oil pump motor slow start promptly. The lubricating oil pump during normal starting, stopping and running (including alternate running) adopts a shared rectifier, a storage battery and respective inverters to drive an alternating current variable frequency motor to supply oil. The emergency oil pump is driven by a direct current motor. Because the storage battery still supplies power to the inverter after the alternating current power supply is cut off, the alternating current variable frequency motor does not stop running immediately, so the direct current motor can be started slowly by adopting a conventional mode, the starting time of the direct current motor is allowed to be longer, and the requirement on the direct current motor power supply (comprising the storage battery) is also reduced.

The technical means adopted by the utility model are as follows.

The utility model provides a allow lubricating oil feeding system of DC accident oil pump motor slow start, contain the accident oil pump module by DC motor drive operation, this accident oil pump module exit linkage lubricating oil feeding system's lubricating oil export, a serial communication port, still contain the main oil pump module, it connects first AC power supply, set up first rectifier behind first AC power supply, the first rectifier export sets up 2 parallelly connected branches, set up the dc-to-ac converter motor in order on every branch road, 2 individual ac converter motors are connected with 2 main oil pumps respectively, connect in the lubricating oil export after 2 lubricating oil pipelines at these 2 main oil pump places converge, first rectifier export still sets up first battery.

Further, the first storage battery is arranged between the first rectifier and the 2-way branch.

Furthermore, the accident oil pump module is connected with a second alternating current power supply, the accident oil pump module comprises a second rectifier and a direct current motor which are connected in sequence, the direct current motor is connected with the accident oil pump, and a second storage battery is arranged on an outlet circuit of the second rectifier.

Furthermore, the capacity of the inverter for supplying power to the corresponding alternating current variable frequency motor is equal to or slightly larger than that of the corresponding alternating current variable frequency motor.

Furthermore, the capacity of the first rectifier for supplying power to the AC inverter motor is greater than or equal to the capacity when 1 AC inverter motor operates and the capacity when another 1 AC inverter motor starts, and the capacity of the rectifier is greater than or equal to the capacity when 2 AC inverter motors operate simultaneously.

Furthermore, the first storage battery for supplying power to the alternating-current variable-frequency motor has a capacity such that when 1 alternating-current variable-frequency motor is in full-load operation, the time for which the first storage battery 13 supplies power to the inverter corresponding to the alternating-current variable-frequency motor is more than 2 times longer than the starting time of the direct-current motor.

Furthermore, the capacity of the second storage battery is larger than that of the first storage battery matched with the alternating-current variable-frequency motor.

And 2 lubricating oil pipelines after confluence in the main oil pump module are sequentially provided with an oil cooler group and an oil filter group.

The AC asynchronous motor of the traditional lubricating oil supply system is changed into an AC variable frequency motor matched with a rectifier, a storage battery and an inverter, and compared with the prior lubricating oil supply system, the lubricating oil supply system has the following beneficial effects.

1. When the generator set is in accident, even if the AC power supply is lost, the running main oil pump still can be continuously operated by the discharge of the storage battery of the inverter because the AC variable frequency motor driven by the inverter with the storage battery is adopted, and the supply of lubricating oil is not interrupted. However, since the power of the main oil pump is large, a large battery capacity is required if the main oil pump is operated at all times. Therefore, the accident oil pump with lower power is started at the same time, and the main oil pump still runs normally at the same time, so that the direct-current motor corresponding to the accident oil pump can still be started slowly in a conventional mode, and the main oil pump is stopped after the start is finished, so that the oil supply can be ensured, and the requirement on the capacity of the storage battery carried by the inverter can be reduced.

2. The inverter can be used for realizing flexible starting of the alternating current variable frequency motor. In the starting process of the generator set, the first main oil pump or the second main oil pump can be started at will. Because of the normal start, a soft start may be employed. I.e. gradually increasing the output frequency from a lower output frequency up to the nominal frequency. In the normal operation process of the generator set, the other main oil pump can be flexibly started at any time, and after the starting is finished, the main oil pump in the original operation is slowly stopped. Thus, the alternate operation of 2 main oil pumps can be realized. In the starting and rotation processes, the power supply and mechanical equipment are not impacted, so that the service life of the machine can be prolonged, and the interruption of lubricating oil in the conversion process is not caused. In addition, during the normal stop of the lubricating oil system, the main oil pump in operation can be stopped slowly by adopting flexible technology.

3. When the lubricating oil system is normally operated, if the main oil pump in operation stops operating due to reasons, another 1 AC variable frequency motor and the DC motor of the accident oil pump can be started simultaneously by depending on the trip signal of the inverter and the system oil pressure drop signal composition or condition, which is similar to the case of the system 2 in which the AC motor is used as the driving motor of the main oil pump, but the AC variable frequency motor can adopt a quick starting mode. Because the utility model discloses a be by the ac inverter motor that the dc-to-ac converter that power electronics constitutes, consequently when needs start fast, can provide the frequency that changes very fast to ac inverter motor starts fast. This is much faster than the starting speed of the ac asynchronous motor in the system 2, so that a continuous supply of lubricating oil can be ensured, which is very advantageous for ensuring the safety of the generator set shafting.

4. After the failed oil pump is started, if the ac power source has recovered power, another main oil pump may be started. And after the starting is finished, the accident oil pump is withdrawn. So that the lubricating oil supplied to the generator set still passes through the oil cooler and the oil filter, thereby ensuring the quality of the lubricating oil.

5. The inverter of the main oil pump motor only needs to provide a starting and running requirement (including conventional starting and quick starting) which meets 1 AC variable frequency motor, and the DC motor of the accident oil pump only adopts the conventional starting technology.

Drawings

Fig. 1 is a schematic view of the lubricating oil supply system of the present invention.

Detailed Description

The utility model provides a lubricating oil feeding system that allows direct current accident oil pump motor to slowly start. As shown in fig. 1, the lubricating oil system module includes a failed oil pump module 2 connected to a second ac power supply 21, including a second rectifier 22 and a dc motor 25 connected in sequence, the dc motor 25 being connected to and driving a failed oil pump 26, a first battery 23 being provided in an outlet circuit of the second rectifier 22, and a lubricating oil outlet of the lubricating oil system being connected to an outlet of the failed oil pump 26.

The utility model discloses a focus is on, the lubricating-oil pump when normally starting, stopping and operation (including the operation of taking turns) adopts shared rectifier, battery and respective inverter drive to exchange inverter motor fuel feeding.

Referring to fig. 1, a main oil pump module 1 is connected to a front pipeline of a lubricating oil outlet. The main oil pump module 1 is connected to a first alternating current power supply 11, a first rectifier 12 is arranged behind the first alternating

current power supply

11, 2 branches connected in parallel are arranged at the outlet of the first rectifier 12, an inverter and an alternating current variable frequency motor are sequentially arranged on each branch, the 2 alternating current variable frequency motors are respectively connected with 2 main oil pumps, 2 lubricating oil pipelines at the 2 main oil pumps are connected to a pipeline before a lubricating oil outlet after being converged, and an oil cooler, an oil filter and other existing devices can be arranged on the converged pipeline to ensure the quality of the lubricating oil. The outlet of the first rectifier 12 is further provided with a storage battery 13, which is preferably arranged between the first rectifier 12 and the 2-way branch.

The 2-way branch is divided into a first branch 101 and a second branch 102 as shown in the figure, the first branch 101 is connected with a first inverter 141 and a first ac inverter motor 151 in sequence, the first ac inverter motor 151 is connected with and drives a first main oil pump 161, the second branch 102 is connected with a second inverter 142 and a second ac inverter motor 152 in sequence, the second ac inverter motor 152 is connected with and drives a second main oil pump 162 in sequence, and the 2-way branch is provided with a relevant valve body such as a check valve at an appropriate position in practice, which is not limited in detail.

The first main oil pump 161, the second main oil pump 162 and the emergency oil pump 26 may all be located in the same main oil tank, and the first ac power source 11 and the second ac power source 21 may be the same power source or different power sources, all depending on the actual power plant requirements.

Based on the above configuration, the first ac inverter motor 151 that drives the first main oil pump 161, and the power supply thereof is derived from the first inverter 141; the second ac inverter motor 152 driving the second main oil pump 162 is supplied with power from the second inverter 142, and the first inverter 141 and the second inverter 142 are supplied with power from the first rectifier 12 equipped with the first battery 13. The capacity of the first rectifier 12 needs to meet the requirement that 1 ac inverter motor operates and then 1 other ac inverter motor starts, and also meets the requirement that 2 ac inverter motors operate simultaneously, so that the 2 ac inverter motors can operate in turn without interrupting oil supply when in operation.

Since the inverter power supply for supplying power to the ac inverter motor has not only the rectifier but also the storage battery, the inverter does not stop operating immediately when the ac power supply is interrupted, so that the dc motor can be a normal dc motor and can be started slowly in a conventional manner without causing interruption of the lubricating oil.

For ease of understanding, the symbol size between the devices in fig. 1 represents the relative capacity size between the devices.

The first inverter 141 and the second inverter 142 for supplying power to the ac inverter motor may have capacities equal to or slightly larger than the capacity of the ac inverter motor.

Since 2 ac inverter motors may work in turn during the operation, in order to ensure the continuity of oil supply, the ac inverter motor in the stopped state must be started first, and the originally operating ac inverter motor can be stopped after the ac inverter motor reaches the rated rotation speed and the supplied oil pressure meets the requirement, therefore, for the first rectifier 12 supplying power to the 2 ac inverter motors, the capacity should meet the following conditions:

1. the capacity is more than or equal to the capacity of 1 AC variable frequency motor during operation and the capacity of 1 AC variable frequency motor during starting;

2. and the capacity is larger than or equal to the capacity when 2 alternating current variable frequency motors run simultaneously.

For the first accumulator 13 to supply power to the ac inverter motor, its capacity should satisfy the condition: when 1 AC inverter motor is operated at full load, the time for supplying power to the inverter is more than 2 times longer than the starting time of the DC motor 25.

When the ac power supply of the rectifier is cut off, since the first storage battery 13 shared by 2 inverters can supply the dc power supply to the inverters in a short time, the operation of the ac inverter motor is not stopped immediately, and at this time, the emergency oil pump 26 driven by the dc motor 25 can be started slowly in a conventional manner without a quick start, which is very advantageous in reducing the impact on the power supply of the dc motor and the dc motor, reducing the storage battery capacity of the dc motor, and extending the life of the dc motor. At the same time, and because of this, it is possible to use a conventional dc motor without using a rapid start dc motor of a special specification. This is possible to reduce the procurement cost and maintenance cost of the dc motor and its power supply system. Meanwhile, the lubricating oil supply of the generator set can be ensured to be uninterrupted, and the purpose of ensuring the safety of a shafting of the generator set is achieved.

Since the dc motor 25 is required to operate for a relatively long time in the event of an accident, the capacity of the second battery 23 should be much greater than that of the first battery 13 associated with the ac inverter motor. In addition, since the energy is supplied by the discharge of the second accumulator 23 when the dc motor 25 is running, the capacity of the second rectifier 22 is different from the requirement of the first rectifier 12 of the ac inverter motor: that is, the second rectifier 22 may satisfy the charging request for the second battery 23.

When the system is in normal operation, the 2 alternating-current variable-frequency motors can perform alternate operation at any time, and any one of the motors can be stopped as long as the oil pumps driven by the 2 variable-frequency motors are confirmed to supply oil normally. If one of the 1 AC variable frequency motors in operation suddenly stops or trips or the outlet pressure of the oil pump is lower than a preset value for some reason, the other 1 AC variable frequency motor and the DC motor can be started simultaneously to ensure that the lubricating oil is not interrupted.

When the AC power supply is in accident or interruption, the main oil pump can utilize the storage battery to supply power to the AC variable-frequency motor uninterruptedly through the inverter and can keep running for a plurality of minutes. During this period, the dc motor of the emergency oil pump module can be started in a conventional manner. When the oil pressure is built at the lubricating oil outlet by the action of the direct current motor, the operation of the alternating current variable frequency motor is stopped. Thus, it is possible to ensure that the continuous supply of the lubricating oil is not interrupted, and it is not necessary to quickly start the dc motor 25 that drives the emergency oil pump module 2, and the impact on the dc power supply system and the emergency oil pump 26 and its drive motor is reduced. Meanwhile, the first storage battery 13 matched with the alternating-current variable-frequency motor is not required to have particularly large capacity.

Claims

1. The utility model provides a allow lubricating oil feeding system of direct current accident oil pump motor slow start, contain accident oil pump module (2) by direct current motor (25) drive operation, this accident oil pump module (2) exit linkage lubricating oil feeding system's lubricating oil export, a serial communication port, still contain main oil pump module (1), it connects first alternating current power supply (11), set up first rectifier (12) after first alternating current power supply (11), first rectifier (12) export sets up 2 parallelly connected branches, set up inverter, alternating current variable frequency motor on every branch road in order, 2 alternating current variable frequency motor is connected with 2 main oil pumps respectively, connect in the lubricating oil export after 2 lubricating oil pipelines at these 2 main oil pumps place converge, first rectifier (12) export still sets up first battery (13).

2. The lubrication oil supply system allowing slow start of a dc accident oil pump motor according to claim 1, wherein the first storage battery (13) is disposed between the first rectifier (12) and the 2-way branch.

3. The lubrication oil supply system allowing slow start of the dc emergency oil pump motor according to claim 1, wherein the emergency oil pump module (2) is connected to a second ac power source (21), the emergency oil pump module (2) comprises a second rectifier (22) and a dc motor (25) connected in series, the dc motor (25) is connected to an emergency oil pump (26), and a second storage battery (23) is disposed on an outlet circuit of the second rectifier (22).

4. The lubrication oil supply system allowing slow start of a dc accident oil pump motor according to claim 1, wherein the inverter supplying power to the corresponding ac inverter motor has a capacity equal to or slightly larger than that of the corresponding ac inverter motor.

5. The lubrication oil supply system allowing slow start of a dc accident oil pump motor according to claim 1, wherein the first rectifier (12) supplying power to the ac inverter motor has a capacity greater than or equal to a capacity when 1 ac inverter motor is operated plus a capacity when 1 ac inverter motor is started, and a rectifier capacity greater than or equal to a capacity when 2 ac inverter motors are simultaneously operated.

6. A lubricating oil supply system allowing a slow start of a dc accident oil pump motor according to claim 3, characterised in that the first accumulator (13) supplying power to the ac inverter motor has a capacity such that when 1 ac inverter motor is operating at full load, the time for which the first accumulator (13) supplies power to the inverter corresponding to the ac inverter motor is more than 2 times longer than the start time of the dc motor (25).

7. A lubricant supply system allowing slow start of a dc accident oil pump motor according to claim 3, characterized in that said second accumulator (23) has a capacity greater than the first accumulator (13) associated with the ac inverter motor.

8. The lubrication oil supply system allowing the slow start of the dc accident oil pump motor according to claim 1, wherein a cold oil filter set and an oil filter set are sequentially disposed on 2 lubrication oil pipelines merged in the main oil pump module (1).