JPH033840B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an apparatus for supplying sealing oil to a shaft seal portion of a rotating electric machine, the interior of which is sealed with a cooling gas such as hydrogen gas.

[Technical background of the invention]

A large-sized rotating electric machine is configured to cool the inside by sealing a cooling gas, such as hydrogen gas, inside the machine. In such a rotating electric machine, a shaft seal portion is provided in the shaft penetrating portion to prevent internal hydrogen gas from leaking to the outside. Seal oil is supplied to this shaft seal portion from a seal oil supply device to cool this shaft seal portion and maintain the sealing performance of this shaft seal portion.

Such a sealing oil supply device is constructed as shown in FIG. That is, 1 is a rotating electric machine, and hydrogen gas is sealed inside the rotating electric machine. Shaft seal parts 3, 3 are provided in the penetrating part of the main shaft 2 of this rotating electrical machine 1, and these shaft seal parts 3,
3 is provided with seal rings 4, 4. A seal oil supply device for supplying seal oil to the shaft seal parts 3, 3 is composed of a shaft seal part cooling system 5 and a shaft seal part seal system 6 .

The shaft seal cooling system 5 includes a cooling seal oil tank 7, and the seal oil in the cooling seal oil tank 7 is pumped to an oil cooler 9 by a cooling seal oil pump 8.
It is sent to the shaft seal parts 3, 3 through the cooling system.
The sealing oil flowing to the outside of the seal rings 4, 4 in the shaft seal parts 3, 3 is removed from the air extraction tank 10.
The oil is returned to the cooling sealing oil tank 7 via. Further, the sealing oil flowing inside the seal rings 4, 4 is configured to be returned to the cooling sealing oil tank 7 via the hydrogen gas separation layer 11, the float trap tank 12, and the air extraction layer 10.

Further, the shaft seal portion seal system 6 is provided with a sealing oil tank 13 for deaeration, and the inside of this sealing oil tank 13 for deaeration is evacuated to a vacuum by a vacuum pump 14. Then, a part of the sealing oil is taken out from the downstream of the oil cooler 9 of the shaft seal cooling system 5 and sprayed into the sealing oil tank 13 for degassing to remove dissolved moisture, air, etc. be done. The sealing oil accumulated in the degassing sealing oil tank 13 is supplied to the sealing surfaces of the seal rings 4, 4 of the shaft seal parts 3, 3 by the sealing oil pump 15 to maintain sealing performance. It is composed of The sealing oil supplied to the sealing surfaces of the seal rings 4, 4 is sent to the cooling sealing oil tank 7 together with the cooling sealing oil, and from this cooling sealing oil tank 7, the sealing oil of the sealing rings 4, 4 is sent to the sealing oil tank 7. The same amount of sealing oil as that supplied to the surface is sent to the degassing sealing oil tank 13. Incidentally, the pressure of the sealing oil supplied to the sealing surfaces of the seal rings 4, 4 needs to be maintained at a predetermined pressure, for example, 0.5 kg/cm ² higher than the pressure of hydrogen gas within the rotating electric machine 1. Further, the required flow rate of the sealing oil supplied to the sealing surfaces of the seal rings 4, 4 varies depending on the rotation speed of the main shaft 2 and the temperature of the sealing oil. For this reason,
A differential pressure regulating valve 16 is provided on the discharge side of the sealing oil pump 15. The pressure of the sealing oil supplied to the sealing surfaces of the seal rings 4, 4 via the pressure guide pipes 17, 17 and the pressure of the sealing oil discharged from the shaft seal parts 3, 3 are applied to the differential pressure regulating valve 16. The differential pressure regulating valve 16 adjusts the flow rate of sealing oil sent to the sealing surfaces of the seal rings 4, 4 in response to these differential pressures, and the sealing oil supplied to the sealing surfaces of the sealing rings 4, 4. is configured to control the pressure and flow rate of the Further, since the sealing oil pump 15 is of a displacement type driven by a motor 18, a pressure regulating valve 19 is provided between the sealing oil pump 15 and the differential pressure regulating valve 16. The surplus sealing oil discharged from the sealing oil pump 15 is transferred from the pressure regulating valve 19 to the deaeration sealing oil tank 1.
3, and the discharge pressure of this sealing oil pump 15 is maintained constant.

[Problems with background technology]

The flow rate of the sealing oil supplied to the sealing surfaces of the seal rings 4, 4 changes depending on the turning operating state, operating change state, and rated operating state of the rotating electric machine. The discharge amount of the sealing oil pump 15 is set constant considering the necessary margin for the maximum required flow rate. Therefore, when the required flow rate is small, the surplus flow rate becomes extremely large. Since this surplus flow is circulated between the sealing oil pump 15 for sealing and the sealing oil tank 13 for degassing, its temperature increases significantly due to the heat of stirring. For this reason, when the rotating electric machine 1 is rotating at a low speed, the temperature of the seal oil in the deaeration seal oil tank 13 rises excessively, and in order to prevent this, the operating time of the seal oil pump 15 is This may cause problems such as having to limit the In particular, in large rotating electric machines such as large turbine generators, the flow rate of sealing oil supplied to the sealing surface during turning operation is 1/10 of that during rated operation, which is an extremely large difference, making the above problems even more severe. It was something that was going to get bigger.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and its purpose is to provide a sealing oil supply device for a rotating electrical machine that can prevent the temperature of the sealing oil from rising during low-speed operation of the rotating electrical machine. be.

[Summary of the invention]

The present invention relates to a shaft seal cooling system that cools the shaft seal by circulating sealing oil through the shaft seal of a rotating electric machine, which has a cooling gas sealed inside, and a shaft seal that is extracted from the shaft seal cooling system. A deaeration sealing oil tank for deaerating oil, a sealing oil pump for supplying the sealing oil in the deaeration sealing oil tank to the sealing surface of the shaft seal portion, and an electric motor for rotationally driving this pump. , the pressure of the sealing oil provided on the discharge side of the sealing oil pump for sealing is supplied to the sealing surface of the shaft sealing portion, and the pressure of the sealing oil discharged from this shaft sealing portion is the same as above. A differential pressure regulating valve controls the flow rate of sealing oil supplied to the sealing surface of the shaft seal portion, and surplus sealing oil discharged from the sealing oil pump is transferred to the deaeration sealing oil tank. and a pressure regulating valve that detects the rotational speed of the rotating electric machine and controls the rotational speed of the electric motor in accordance with this rotational speed to increase the discharge amount of the sealing oil pump by a predetermined amount than the flow rate. It is equipped with a discharge amount control mechanism that controls the discharge amount. Therefore, the discharge amount of the sealing oil pump changes in accordance with the rotational speed of the rotating electric machine, and is controlled in accordance with the necessary amount to be supplied to the sealing surface of the shaft seal part, and the excess discharge amount is Even if the operating state changes, it is limited within a predetermined range, and therefore, even during low-speed operation, excessive temperature rise of the sealing oil can be prevented.

[Embodiments of the invention]

A first embodiment of the present invention will be described below with reference to FIGS. 2 to 4. In the figure, 101 is a rotating electrical machine such as a turbine generator, and a cooling gas such as hydrogen gas is sealed inside the machine. and,
Shaft seal portions 103, 103 are provided in the penetrating portion of the main shaft 102 of this rotating electric machine 101. A seal ring 1 is provided in the shaft seal portions 103, 103.
04 and 104 are provided. The sealing surfaces of these seal rings 104, 104 are in close contact with the outer periphery of the main shaft 102, and these seal rings
4, 104 is divided in the circumferential direction in order to absorb vibrations of the main shaft 102 or to allow changes in the thickness of the oil film on the sealing surface, and is configured so that the inner diameter, that is, the diameter of the sealing surface can be changed.

These shaft seal portions 103, 103 are configured to be supplied with sealing oil for cooling and maintaining sealing performance, and a sealing oil supply device that supplies this sealing oil will be described below. That is, this sealing oil supply device is composed of a shaft seal cooling system 105 and a shaft seal sealing system 106 .

The shaft seal cooling system 105 is constructed as follows. 107 is a cooling sealing oil tank in which sealing oil is stored. The sealing oil in the cooling sealing oil tank 107 is sent to the oil cooler 109 by the cooling sealing oil pump 108, and after being cooled to about 40° C., it is passed through the cooling sealing oil supply pipe 110 to the oil cooler 109. It is supplied into the shaft seals 103, 103 and is configured to cool the inside. Of the cooling sealing oil supplied into these shaft seals 103, 103, the sealing oil that has flowed to the outside of the seal rings 104, 104 is sent to the air extraction tank 111, where the mixed air is separated. Cooling seal oil tank 10
7. Further, the sealing oil flowing inside the seal rings 104, 104 is sent to a hydrogen gas separation tank 112, and after the mixed hydrogen gas is separated, a float trap tank 113
The air is sent to the air extraction tank 111 via the air extraction tank 111 and returned to the cooling sealing oil tank 107 from the air extraction tank 111. The float trap tank 113 is equipped with a float valve inside, and when a predetermined amount or more of hydrogen gas accumulates and the oil level of the internal sealing oil drops, the float valve closes and prevents hydrogen gas from flowing into the air extraction tank 111. This is to prevent this.

Further, the shaft seal portion seal system 106 is configured as follows. That is, 115 is a sealing oil tank for degassing, and the vacuum pump 1 is installed inside this tank.
16, it is constantly evacuated to vacuum. A portion of the sealing oil is removed from the outlet pipe 11 from the downstream side of the oil cooler 109 of the shaft seal cooling system 105 .
7, and is sprayed into the sealing oil tank 115 for degassing from a spray nozzle 119 via a float valve 118, and the water, air, etc. contained therein are completely degassed and cleaned. and,
The sealing oil accumulated in this deaeration sealing oil tank 115 is pumped to the oil supply pipe 1 by a sealing oil pump 120.
21 to the sealing surfaces of the seal rings 104, 104 of the shaft seal parts 103, 103, and is configured to maintain the sealing performance of the shaft seal parts 103, 103. The sealing oil supplied to the sealing surfaces of the seal rings 104, 104 is added to the cooling sealing tank 10 along with the cooling sealing oil.
7, and from this cooling seal oil tank 107, the same amount of seal oil as the amount supplied to the sealing surfaces of the seal rings 104, 104 via the take-out pipe 117 is supplied to the degassing seal oil. It is returned to tank 115. In addition, these seal rings 104, 104
The sealing oil supplied to the sealing surface of the rotating electrical machine 101 is completely degassed in the degassing sealing oil tank 115 to remove moisture and air, so that moisture, air, etc. are removed from the hydrogen gas in the rotating electric machine 101. This prevents contamination and does not cause a decrease in cooling efficiency due to hydrogen gas contamination. Further, the sealing oil pump 120 is of a displacement type such as a gear pump, and is driven by a driving electric motor 122 such as a three-phase induction motor. A differential pressure regulating valve 123 is provided on the discharge side of the sealing oil pump 120. A seal ring 10 is connected to this differential pressure regulating valve 123 via pressure guide pipes 124, 124.
The pressure of the sealing oil supplied to the sealing surfaces of 4 and 104 and the pressure of the sealing oil discharged from the shaft seal parts 103 and 103 are introduced, and this differential pressure regulating valve 123 adjusts the seal ring in response to these differential pressures. 104,10
The pressure and flow rate of the sealing oil sent to the sealing surfaces of the seal rings 104, 104 are maintained at predetermined values by adjusting the flow rate of the sealing oil sent to the sealing surfaces of the seal rings 104, 104. In addition, the seal oil pump 12 for the seal
0 and the differential pressure regulating valve 123 is a pressure regulating valve 12.
6 is provided, and a sealing oil pump 12 for sealing is provided.
Excess sealing oil out of the sealing oil discharged from
is sent to the degassing seal oil tank 115 and returned to the deaeration seal oil tank 115 to maintain the discharge pressure of the seal oil pump 120 constant and to recycle the seal oil. The structure is such that the sealing oil is completely purified through circulation.

This device also includes a sealing oil pump 12.
A discharge amount control mechanism 130 that controls the discharge amount of 0 is provided, and its configuration will be described below. That is, 140 is a rotation meter generator provided at the shaft end of the rotating electric machine 101 or a rotation detector using a non-contact pulse signal, and generates an electromotive force and a pulse signal proportional to the rotational speed of the rotating electric machine 101. It is something. 141 is a detection signal converter that converts the detection signal of the rotation detector into a control signal corresponding to the rotation speed of the main shaft of the rotating electric machine 101; 142 is a detection signal converter that converts a detection signal of the rotation detector into a control signal corresponding to the rotation speed of the turbine generator; A control output setting device for selecting only the range and adjusting it as an output signal, 143 is a voltage configured by a voltage/frequency control inverter installed in the power supply line of the drive motor 122 of the sealing oil pump 120 It is a control device.

Then, the electromotive force or pulse signal of the rotation detector 140 is sent to the detection signal converter 141 as a value that increases or decreases in proportion to the rotation speed of the rotating electric machine 101, and is sent to the detection signal converter 141, where the electromotive force or pulse signal is changed from 0 to 100 with respect to the rated rotation speed of the rotating electric machine 101. %
A control signal proportionally divided into the rotation range (usually 1 to
5V DC). For example, signal converter 1
When the output signal of 41 is 1V DC, the rotating electric machine 10
1 is a stopped state, and 5V DC is a state of operation at rated rotation. The output signal of this signal converter 141 is the control output setter 1
At 42, the signal is converted into a control signal within a certain range (usually in the range of 4 to 20 mADC or 1 to 5V DC) by a proportional calculation operation, and sent as an input signal to the voltage control device 143. Here, the rotation speed of the drive motor 122 is increased or decreased by changing the power frequency of the drive motor 122 in proportion to this control signal.

Therefore, when the input signal of the control output setting device 142, that is, the rotation speed of the rotating electrical machine 101 is in a range of a certain value or more, the output signal of the control output setting device 142, that is, the rotation of the driving electric motor 122 of the sealing oil pump 120 It increases or decreases while maintaining a certain difference from the number.

Rotating electric machine 101 and drive electric motor 12 in this case
The relationship between rotation speed and rotation speed is as shown in FIG. Since the sealing oil pump 120 is a positive displacement pump such as a gear pump, its discharge amount increases or decreases in proportion to its rotational speed. Therefore, the discharge amount of the sealing oil pump 120 is increased or decreased by increasing or decreasing the rotational speed of the driving electric motor 122. Therefore, the discharge amount of the sealing oil pump 120 changes as shown by the solid line abcd in FIG. 4 as the rotational speed of the rotating electric machine 101 decreases. In addition, the seal ring 10 of the rotating electric machine 101
4, 104 decreases as shown by the dotted line in FIG. Decrease to maintain range.

Therefore, the rotation speed, etc. of the rotating electric machine 101 changes,
When the flow rate of the seal oil supplied to the seal surfaces of the seal rings 104, 104 changes, the discharge amount of the seal oil pump 120 changes accordingly.
Therefore, if the flow rate of the sealing oil supplied to the sealing surfaces of the seal rings 104, 104 changes, the discharge amount of the sealing oil pump 120 will be adjusted to the surplus discharge amount corresponding to the recirculation flow rate required for the above flow rate. controlled by the added flow rate. Therefore, even when the rotational speed of the rotating electrical machine 101 is low, an unnecessarily large amount of sealing oil is deposited in the degassing sealing oil tank 115 and the sealing oil pump 1.
20, and the temperature of the sealing oil is prevented from rising.

Note that the present invention is not limited to the first embodiment described above.

For example, FIG. 5 shows a second embodiment of the present invention. In this second embodiment, the drive motor 122 is a secondary high resistance three-phase squirrel cage induction motor, and the speed change detector 1
40 as a speed change detection generator, as shown in FIG.
This detection signal is used to control the primary winding voltage of the drive motor 122 via an amplifier and a reference voltage setter 150.

〔Effect of the invention〕

As described above, the present invention relates to a shaft seal cooling system that circulates sealing oil through a shaft seal of a rotating electric machine in which cooling gas is sealed to cool the shaft seal, and a shaft seal cooling system that cools the shaft seal. a deaeration seal oil tank for deaerating the deaeration seal oil; a seal oil pump for supplying the seal oil in the deaeration seal oil tank to the seal surface of the shaft seal portion; and a seal oil pump for rotating the pump. It is provided on the discharge side of the electric motor and this sealing oil pump, and corresponds to the differential pressure between the pressure of the sealing oil supplied to the sealing surface of the shaft seal part and the pressure of the sealing oil discharged from this shaft seal part. A differential pressure regulating valve controls the flow rate of the sealing oil supplied to the sealing surface of the shaft seal portion, and surplus sealing oil discharged from the sealing oil pump is transferred to the degassing seal. A pressure regulating valve that returns to the oil tank and a rotational speed of the rotating electric machine are detected, and the rotational speed of the electric motor is controlled in accordance with this rotational speed, so that the discharge amount of the sealing oil pump is increased by a predetermined amount than the flow rate. It is equipped with a discharge amount control mechanism that controls the discharge amount. Therefore, the discharge amount of the sealing oil pump changes in accordance with the rotational speed of the rotating electric machine, and is controlled in accordance with the necessary amount to be supplied to the sealing surface of the shaft seal part, and the excess discharge amount is Even if the operating state changes, it is limited within a predetermined range, and therefore, even during low-speed operation, the sealing oil has great effects such as being able to prevent an excessive temperature rise.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a conventional example. Figures 2 to 4 show the first embodiment of the present invention, Figure 2 is a schematic configuration diagram, Figure 3 is a diagram showing changes in rotational speed of the rotating electric machine and drive motor, and Figure 4 is a sealing oil diagram. FIG. 2 is a diagram showing changes in flow rate. Further, FIG. 5 is a schematic configuration diagram of the second embodiment. 101... Rotating electric machine, 103... Shaft seal section,
104...Seal ring, 105 ...Shaft seal cooling system, 106 ...Shaft seal seal system, 107
...Sealing oil tank for cooling, 115...Sealing oil tank for degassing, 120...Sealing oil pump for sealing, 1
22... Drive electric motor, 123... Differential pressure regulating valve,
126...Pressure regulating valve, 130 ...Discharge amount control mechanism.

Claims (1)

[Claims] 1 A shaft seal cooling system that cools the shaft seal by circulating seal oil through the shaft seal of a rotating electric machine, which has cooling gas sealed inside, and a shaft seal cooling system that cools the shaft seal. A deaeration seal oil tank for degassing, a seal oil pump that supplies the seal oil in the deaeration seal oil tank to the seal surface of the shaft seal portion, and an electric motor that drives the seal oil pump. and the pressure of the sealing oil provided on the discharge side of this sealing oil pump and supplied to the sealing surface of the shaft seal part and the pressure of the sealing oil discharged from this shaft sealing part. A differential pressure regulating valve that controls the flow rate of sealing oil supplied to the sealing surface of the shaft seal portion and the sealing oil pump for sealing that surplus sealing oil discharged from the sealing oil for degassing A pressure regulating valve that returns to the tank,
A discharge amount control mechanism that detects the rotation speed of the rotating electrical machine, controls the rotation speed of the electric motor in accordance with the rotation speed, and controls the discharge amount of the sealing oil pump to a discharge amount that is higher than the flow rate by a predetermined amount. A sealing oil supply device for a rotating electrical machine, characterized by comprising: