阅读说明：本技术 由变频电动机与直流电动机共同组成的润滑油供油系统 (Lubricating oil supply system composed of variable frequency motor and direct current motor ) 是由 张治宇 李�和 于 2019-07-02 设计创作，主要内容包括：本发明由变频电动机与直流电动机共同组成的润滑油供油系统,包括第一供油模块、第二供油模块、事故供油模块、润滑油处理模块以及润滑油出口,其特征在于,其中,第一供油模块包括第一变频电动机、第一变频器、第一交流电源、第一主油泵及第一输油管道；第一变频流电动机通过第一变频器与第一交流电源连接；再有,第二供油模块包括第二变频电动机、第二变频器、第二交流电源、第二主油泵及第二输油管道；第二变频电动机通过第二变频器与第二交流电源连接；实现了对于两个主油泵的缓慢起动或停止,事故油泵的缓慢起停及快速起动,确保供油不中断,同时还可以减少对于供电系统的冲击,进一步提升了经济和社会效益。(The invention relates to a lubricating oil supply system composed of a variable frequency motor and a direct current motor, which comprises a first oil supply module, a second oil supply module, an accident oil supply module, a lubricating oil treatment module and a lubricating oil outlet, and is characterized in that the first oil supply module comprises a first variable frequency motor, a first frequency converter, a first alternating current power supply, a first main oil pump and a first oil pipeline; the first variable-frequency motor is connected with a first alternating current power supply through a first frequency converter; moreover, the second oil supply module comprises a second variable frequency motor, a second frequency converter, a second alternating current power supply, a second main oil pump and a second oil pipeline; the second variable frequency motor is connected with a second alternating current power supply through a second frequency converter; the slow start or stop of the two main oil pumps and the slow start, stop and fast start of the accident oil pump are realized, the oil supply is ensured not to be interrupted, meanwhile, the impact on a power supply system can be reduced, and the economic and social benefits are further improved.)

1. By the common lubricating oil feeding system who constitutes of inverter motor and DC motor, including first oil feed module (101), second oil feed module (102), accident oil feed module (103), lubricating oil processing module (200) and lubricating oil export (300), its characterized in that:

the first oil supply module (101) comprises a first variable frequency motor (1), a first frequency converter (4), a first alternating current power supply (9), a first main oil pump (12) and a first oil conveying pipeline (15);

the first variable-frequency motor (1) is connected with the first alternating current power supply (9) through the first frequency converter (4); one end of the first main oil pump (12) is connected with the first variable frequency motor (1), and the other end of the first main oil pump is connected with the first oil pipeline (15); the first frequency converter (4) has a first battery (7);

furthermore, the second oil supply module (102) comprises a second variable frequency motor (2), a second frequency converter (5), a second alternating current power supply (10), a second main oil pump (13) and a second oil conveying pipeline (16);

the second variable-frequency motor (2) is connected with the second alternating current power supply (10) through the second frequency converter (5); one end of the second main oil pump (13) is connected with the second variable frequency motor (2), and the other end of the second main oil pump is connected with the second oil pipeline (16); the second frequency converter (5) has a second battery (8);

one end of the first oil pipeline (15) and one end of the second oil pipeline (16) are respectively connected with the lubricating oil treatment module (200); the first oil supply module (101) and the second oil supply module (102) are connected to the lubricating oil treatment module (200) in parallel through the first oil pipeline (15) and the second oil pipeline (16), respectively.

2. The system for supplying lubricating oil, which is composed of a variable frequency motor and a direct current motor in combination, as set forth in claim 1, wherein:

the emergency oil supply system also comprises an emergency oil supply module (103) which comprises a direct-current power supply (11), a controller (6), a direct-current motor (3), an emergency oil pump (14) and an emergency oil pipeline (17);

the direct current motor (3) is connected with the direct current power supply (11) through the controller (6); one end of the accident oil pump (14) is connected with the direct current motor (3), and the other end of the accident oil pump is connected with the accident oil pipeline (17);

one end of the accident oil conveying pipeline (17) is connected with the lubricating oil outlet (300); the accident oil supply module (103) is directly connected to the lubricating oil outlet (300) through the accident oil delivery pipe (17).

Technical Field

The invention relates to the field of thermal power generation, in particular to a lubricating oil supply system which is composed of a variable frequency motor and a direct current motor.

Background

A power generating unit in a thermal power plant is a machine that rotates at high speed during power generating operation, and a large amount of oil is required for lubrication of an operation joint portion between a support bearing and a thrust bearing and a friction portion that operates at high speed. The oil supply system for supplying lubricating oil as a generator set causes serious damage to the equipment of the generator set even if a short interruption occurs, and therefore, it is necessary to ensure continuous and stable operation of the lubricating oil system.

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

the system 1: when starting, 1 start/stop oil pump driven by an alternating current asynchronous motor, a coaxial working 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: start/stop and work oil pumps driven by 2 ac asynchronous motors +1 emergency oil pump driven by a dc motor (as shown in fig. 2).

The system 1 is mainly characterized in that an oil pump driven by an alternating current asynchronous motor is used during starting and stopping, a coaxial oil pump installed on a shaft of a turbogenerator is used for supplying oil during normal operation, and the oil pump driven by a direct current motor is started for supplying oil during an accident. Because the shafting of the generator set is very big in mass and therefore very big in inertia, when an accident happens, the time for reducing the rated rotating speed to the state of not meeting the oil supply condition by the inertia of the generator set is about 1 minute or more, and therefore, the starting time of the oil pump driven by the direct current motor is not very fast when the accident happens in the system. However, the system 2 is different from the system 1, and is the same as the system 1 in normal start/stop, and also adopts an oil pump driven by an alternating current asynchronous motor as a start oil pump and a stop oil pump, but still adopts an oil pump driven by an alternating current asynchronous motor as a working oil pump when the generator set is in normal operation; in case of accident, because the inertia of the ac asynchronous motor and the oil pump driven by the ac asynchronous motor is very small, the ac asynchronous motor will not provide enough lubricating oil soon after the oil pump is de-energized, and therefore, the emergency oil pump driven by the dc motor must be started at a fast speed to provide lubricating oil for the generator set instead of the working oil pump in a short time, so as to ensure that the supply of the lubricating oil is not interrupted, so as to prevent the shafting of the generator set from being damaged.

The starting of the direct current motor in the system 1 and the system 2 is realized by connecting a starting resistor in series in an armature loop of the direct current motor, and the starting resistor is generally connected in series with 1; 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 very fast, and the requirement on the starting time is very short, so that the resistance value of the starting resistor connected in series is very small, and the starting current is very large; when the system 2 loses the alternating current power supply once an accident occurs in actual operation, the requirements on the starting speed and the time of an accident oil pump driven by a direct current motor are stricter, so that the operation risk is high, but for generator sets such as a combustion engine and the like, only the system 2 with high operation risk can be adopted for supplying oil based on the structure of the generator sets.

In view of the problems of the lubricating oil system of the system 2, in order to reduce the risk of oil supply interruption, a brand new lubricating oil driving mode needs to be provided, the original oil pump driving mode is improved, the reliability of the lubricating oil system is greatly improved, meanwhile, the impact on a power supply system can be reduced, the supply of lubricating oil is ensured not to be interrupted, the running stability of a generator set can be improved, the probability and risk of damage of a shafting are reduced, the running time of the generator set is prolonged, and the economic and social benefits are further improved.

Disclosure of Invention

In view of the above-mentioned deficiency of the prior art, the invention has proposed a kind of lubricating oil supply system composed of frequency conversion motor and direct-current motor together innovatively, it has changed the system architecture that the oil pump of starting/stopping and working that is driven by 2 exchanges asynchronous motor and oil pump +1 direct-current motor driven accident oil pump starts in the original lubricating oil system, adopt the alternating current power supply to drive the frequency conversion motor through the frequency converter with storage battery while starting, stopping and running 2 main oil pumps normally, the starting/stopping of the oil pump of accident also adopts the direct-current power supply to drive the direct-current motor through the controller at the same time; therefore, the main oil pump can be slowly and gradually started and stopped, and the accident oil pump can be respectively slowly started and quickly started in different accident conditions, so that the continuous supply of lubricating oil is ensured, the shafting safety of the generator set is protected, the impact on a power supply and mechanical equipment caused by the sudden start/stop of the main oil pump and the sudden start of the accident oil pump in the process of sudden start is reduced, the generator set, the power supply and the mechanical equipment are protected, the running time of the generator set is prolonged, and the economic and social benefits are further improved.

The technical means adopted by the invention are as follows:

the invention provides a lubricating oil supply system jointly composed of a variable frequency motor and a direct current motor, which comprises a first oil supply module, a second oil supply module, an accident oil supply module, a lubricating oil treatment module and a lubricating oil outlet, and is characterized in that the first oil supply module comprises a first variable frequency motor, a first frequency converter, a first alternating current power supply, a first main oil pump and a first oil conveying pipeline; wherein the first inverter motor is connected to the first ac power supply via the first inverter; one end of the first main oil pump is connected with the first variable frequency motor, and the other end of the first main oil pump is connected with the first oil pipeline; the first inverter includes a first battery; moreover, the second oil supply module comprises a second variable frequency motor, a second frequency converter, a second alternating current power supply, a second main oil pump and a second oil pipeline; wherein the second inverter motor is connected to the second ac power supply through the second inverter; one end of the second main oil pump is connected with the second variable frequency motor, and the other end of the second main oil pump is connected with the second oil pipeline; the second inverter includes a second battery; in addition, one end of the first oil pipeline and one end of the second oil pipeline are respectively connected with the lubricating oil processing module; the first oil supply module and the second oil supply module are respectively connected to the lubricating oil treatment module in parallel through the first oil pipeline and the second oil pipeline.

The lubricating oil supply system formed by the variable frequency motor and the direct current motor further has the following characteristics.

The emergency oil supply module comprises a direct-current power supply, a controller, a direct-current motor, an emergency oil pump and an emergency oil pipeline; wherein the dc motor is connected to the dc power supply through the controller; one end of the accident oil pump is connected with the direct current motor, and the other end of the accident oil pump is connected with the accident oil pipeline; one end of the accident oil pipeline is connected with the lubricating oil outlet; the accident oil supply module is directly connected to the lubricating oil outlet through the accident oil pipeline.

Advantageous effects

Through the innovative lubricating oil supply system composed of the variable frequency motor and the direct current motor, the original driving oil pump mode is improved, the reliability of the lubricating oil system is greatly improved, meanwhile, the impact on the power supply system can be reduced, the supply of lubricating oil is ensured not to be interrupted, the running stability of the generator set can be improved, the probability and risk of damage of a shaft system are reduced, the running time of the generator set is prolonged, and the economic and social benefits are further improved.

Drawings

Fig. 1 is a schematic diagram of a lubricating oil supply system composed of a variable frequency motor and a direct current motor, in which the names and connection relations of key devices of the system structure are indicated.

Fig. 2 is a schematic structural diagram of a conventional lubricating oil supply system 2 (a start/stop and operation oil pump driven by 2 ac asynchronous motors + an emergency oil pump driven by 1 dc motor).

Description of the reference symbols:

1: a first variable frequency motor;

2: a second variable frequency motor;

3: a DC motor;

4: a first frequency converter;

5: a second frequency converter;

6: a controller;

7: a first storage battery;

8: a second storage battery;

9: a first alternating current power supply;

10: a second alternating current power supply;

11: a direct current power supply;

12: a first main oil pump;

13: a second main oil pump;

14: an emergency oil pump;

15: a first oil transport pipeline;

16: a second oil transport pipeline;

17: an accident oil pipeline;

18: a first oil cooler;

19: a second oil cooler;

20: a first oil filter;

21: a second oil filter;

101: a first oil supply module;

102: a second oil supply module;

103: an accident oil supply module;

200: a lubricating oil treatment module;

300: and a lubricating oil outlet.

Detailed Description

The following detailed description of the embodiments, structures, features and effects of a lubricating oil supply system composed of a variable frequency motor and a dc motor according to the present invention will be made with reference to the accompanying drawings, as follows:

FIG. 1 is a schematic diagram of a lubricating oil supply system composed of an inverter motor and a DC motor according to the present invention; as can be seen from the figure, the system comprises a first oil supply module 101, a second oil supply module 102, an accident oil supply module 103, a lubricating oil treatment module 200 and a lubricating oil outlet 300, and is characterized in that the first oil supply module 101 comprises a first variable frequency motor 1, a first frequency converter 4, a first alternating current power supply 9, a first main oil pump 12 and a first oil pipeline 15; wherein the first inverter motor 1 is connected to the first ac power supply 9 via the first inverter 4; one end of the first main oil pump 12 is connected to the first inverter motor 1, and the other end is connected to the first oil delivery pipe 15; the first inverter 4 has a first battery 7; the second oil supply module 102 includes a second inverter motor 2, a second inverter 5, a second ac power supply 10, a second main oil pump 13, and a second oil pipeline 16; wherein the second inverter motor 2 is connected to the second ac power supply 10 via the second inverter 5; one end of the second main oil pump 13 is connected to the second inverter motor 2, and the other end thereof is connected to the second oil delivery pipe 16; the second inverter 5 includes a second battery 8; one ends of the first oil delivery pipe 15 and the second oil delivery pipe 16 are connected to the lubricating oil treatment module 200, respectively; the first oil supply module 101 and the second oil supply module 102 are connected in parallel to the lubricating oil treatment module 200 through the first oil delivery pipe 15 and the second oil delivery pipe 16, respectively.

As mentioned above, the two main oil supply modules in the lubricating oil supply system, the first oil supply module 101 and the second oil supply module 102, both adopt a variable frequency motor structure with a frequency converter, wherein the first frequency converter 4 and the second frequency converter 5 are respectively composed of novel power electronic accessories matched with the first variable frequency motor 1 and the second variable frequency motor 2 connected thereto, namely, a "voltage source type frequency converter with a storage battery", which can drive the motor to realize stable and impact-free starting or stopping by gradually increasing the output power of the frequency converter or gradually decreasing the output power of the transformer, and when the motor is started and then enters into normal operation, the frequency converter provides a power frequency power supply with stable frequency; meanwhile, the flexible technology for gradually reducing the output power of the transformer is adopted when all the frequency converters stop operating the motor, so that the inverter is prevented from being damaged possibly due to too high back electromotive force when the high-speed motor is braked; moreover, because the adopted first frequency converter 4 and the adopted second frequency converter 5 are both provided with the first storage battery 7 and the second storage battery 8 which are connected in parallel with the first frequency converter 4 and the second frequency converter 5, when the power plant loses an alternating current power supply, the storage battery attached to the frequency converter can continuously provide a direct current power supply for the output of the frequency converter in a short time so as to maintain the capacity required by the rated output of the variable frequency motor within minutes without additionally arranging a charging device, so that the running of the variable frequency motor is not interrupted, and at the moment, an emergency oil pump driven by the direct current motor and a corresponding controller can be synchronously and gradually started, so that the supply of lubricating oil is not interrupted, and the shafting safety of a generator; in addition, due to the fact that the first alternating current power supply 9 and the second alternating current power supply 10 are adopted, the practical environment of most power plants can be well adapted, and other devices do not need to be added.

Wherein the present invention further has the following structural features as shown in fig. 1.

The emergency oil supply system also comprises an emergency oil supply module 103, which comprises a direct-current power supply 11, a controller 6, a direct-current motor 3, an emergency oil pump 14 and an emergency oil pipeline 17; wherein the dc motor 3 is connected to the dc power supply 11 through the controller 6; one end of the accident oil pump 14 is connected with the direct current motor 3, and the other end is connected with the accident oil pipeline 17; one end of the accident oil pipeline 17 is connected to the lubricating oil outlet 300; the emergency oil supply module 103 is directly connected to the lubricant outlet 300 through the emergency oil delivery pipe 17.

The controller 6 adopted in the emergency oil supply module 103 as described above is composed of a novel power electronic device, and can provide 2 starting modes for the connected dc motor 3, one of which is to realize slow start and stop of the dc motor 3 by controlling the output current to slowly increase or slowly decrease, so as to reduce the impact on the equipment (including the power supply, the motor and the oil pump), and the other is that when the rapid start is required, the current output by the controller 6 can be continuously maintained at the maximum current allowed by the dc motor 3 until the motor start is completed, so that the fastest starting speed can be achieved; in both starting modes, the controller 6 always outputs a direct current power supply.

The invention has the following characteristics in practical application.

When the generator set has an accident, even if the alternating current power supply is lost, the first main oil pump 12 and the second main oil pump 13 in operation still can be discharged by the first storage battery 7 carried by the first frequency converter 4 or the second storage battery 8 carried by the second frequency converter 5 to continue to operate without interrupting the supply of lubricating oil because the variable frequency motor driven by the frequency converter with the storage battery is adopted; however, since the power of the main oil pump is large, if the main oil pump is operated all the time, the large battery capacity is needed, and therefore, the accident oil pump 14 with small power can be started, so that the oil supply can be ensured, and the requirement on the battery capacity carried by the frequency converter can be reduced; at this time, the main oil pump still runs normally, so the direct current motor 3 driving the accident oil pump can still be started slowly by adopting a flexible technology, and the operation of the main oil pump is stopped after the start is finished.

In the normal starting process of the generator set, the first main oil pump 12 or the second main oil pump 13 can be started slowly and flexibly at will, namely, the output frequency is gradually increased from the lower output frequency to the rated frequency, so that the power supply cannot be impacted, the mechanical equipment cannot be impacted, and the service life of the machine can be prolonged; in the normal operation process of the generator set, the first main oil pump 12 or the second main oil pump 13 can be started by a flexible technology at any time, and after one main oil pump is started, the main oil pump in the original operation is slowly stopped, so that the alternate operation of 2 main oil pumps can be realized. In the rotation process, impact is not generated on a power supply or equipment, and the interruption of lubricating oil supply is avoided; in addition, the main oil pump in operation can also be slowly stopped by adopting flexible technology during the normal stop process of the lubricating oil system.

If the running main oil pump stops running due to reasons, the direct current motor 3 of the accident oil supply module 103 can be quickly started by depending on the composition or condition of a tripping signal of a power supply of the first variable frequency motor 1 or the second variable frequency motor 2 and a system oil pressure drop signal, and the direct current motor 3 driven by the controller 6 consisting of power electronic devices can provide a large constant current for the direct current motor when needing quick starting, so that the direct current motor is quickly started, which is much faster than the starting speed of the direct current motor directly driven by the existing direct current power supply and a starting resistor, so that the continuous supply of lubricating oil can be ensured, and the shafting safety of a generating set can be more reliably ensured; after the emergency oil pump 14 is started, if the ac power supply supplying power to the dc power supply 11 still has the power supply condition, another good main oil pump can be started, and the emergency oil pump 14 is removed after the start is completed, so that the lubricating oil supplied to the generator set can still be optimally processed by the first oil cooler 18 and the first oil filter 20 or the second oil cooler 19 and the second oil filter 21 in the lubricating oil processing module 200, and thus, the quality of the lubricating oil with higher quality can be ensured.

The invention improves the original mode of driving the oil pump by innovatively providing the lubricating oil supply system which is formed by the variable frequency motor and the direct current motor, thereby greatly improving the reliability of the lubricating oil system, simultaneously reducing the impact on the power supply system and ensuring the uninterrupted supply of the lubricating oil, thereby improving the running stability of the generator set, reducing the probability and risk of damaging the shafting, prolonging the running time of the generator set and further improving the economic and social benefits.