JPS60210147A - Ventilator of vertical shaft rotary electric machine - Google Patents

Abstract

PURPOSE:To reduce power consumption without loss of cooling effect by stopping a lower fan simultaneously with the stop of a rotor when fans are mounted at the upper and lower portions of a rotor, and stopping the upper fan after the prescribed time is elapsed. CONSTITUTION:When upper and lower fans 11, 12 are respectively provided at the upper and lower portions of a rotor 3 to ventilate and cool the rotor 3, the fan 12 is stopped near the stopping time point of the rotor 3, and the fan 11 is stopped after it is continued in operation for the prescribed time. Thus, a bracket arm and a vibrationproof stay prevent from excessively rising at the temperature, and power consumption is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an improvement of a ventilation system for a shaft rotating electric machine, and more particularly to an improvement of a ventilation system for a high-speed, large-capacity water turbine generator.

[Background of the invention]

Generally, in high-speed, large-capacity water turbine generators, etc., the loss in the generator is large, and a mechanical fan installed on the rotor cannot provide sufficient cooling effect. A ventilation system is often used in which an electric fan is installed at the bottom and the fan forcibly cools the water turbine generator. In addition, this fan, as shown in Figure 2,
Even after the rotor is stopped, the rotor continues to operate within the Aτ time to prevent the vibration isolating stay and the upper bracket arm from rising excessively in temperature. This is because when the rotor stops, high-temperature air stagnates at the top of the generator, increasing the temperature of the bracket arm and anti-vibration stay, causing thermal expansion of the bracket arm and anti-vibration stay.

This is because there is a risk of excessive compressive force being generated on the concrete foundation. To prevent this, the fan is operated even after the rotor has stopped to cool the bracket arm and vibration isolation stay.

By the way, the time Aτ for operating the fan after the rotor stops is:
The temperature of the bracket arm and vibration isolating stay is set so that the temperature T2 is lower by lτ than the temperature T during steady operation shown in Fig. 2, but in general, Δτ is about 30 minutes to 1 hour. Although it is often selected, the power consumption during this period is 500 to 1
000 KWh, which had the disadvantage of high power consumption.

[Purpose of the invention]

The purpose of the present invention is to stop only the lower fan at an early stage,
The purpose of the upper fan is to continue operating even after the rotor has stopped, as in the past, to prevent excessive temperature rises in the bracket arm and vibration isolation stay, and to reduce power consumption.

[Embodiments of the invention]

Hereinafter, the present invention will be described in detail with reference to Examples.

In FIG. 1, 1 is a generator main shaft, 3 is a rotor directly connected to the main shaft 1, 2 is a thrust bearing device, and 4 is an upper bearing device, which supports the rotor. Further, 5 is a stator, 6 is a base that supports the stator, and 7. is an air cooler, 8 is an upper bracket arm, 9 is a vibration isolation stay, 10 is an air passage, 11 is an upper fan, and 12 is a lower fan, and the amount of heat generated in the rotor 3 and stator 5 is and lower fan 1
It is carried away by the air forcibly circulated by the air cooler 7 and cooled by the air cooler 7. Also, 10 is a wind path,
It is designed to prevent cooling air from escaping to the outside. On the other hand, a plurality of bracket arms 8 are provided on the outer periphery of the upper bearing device 4.
and anti-vibration stays 9 are arranged radially to transmit the radial force applied to the upper bearing device 4 to the concrete foundation 14 via the metal spring 15 and the base 13, so that the rotor 3 can operate safely. It has become.

By the way, the bracket arm 8 and the vibration isolation stay 9 are made of steel and are lightweight, so they are easily affected by temperature. On the other hand, the concrete foundation 14 has a large mass and many heat radiation surfaces, so the temperature of the generator As the temperature of the foundation 14 does not change when the temperature of the generator increases, only the arm 8 and stay 9 will be able to absorb 1111% of the heat, and an excessive amount of heat will be generated between the arm 8 and stay 9 and the concrete foundation 14. A compressive force acts on the foundation 14, which may cause cracks to occur in the foundation 14. This temperature rise in the generator often occurs when hot air stagnates in the upper part of the generator after the rotor 3 has stopped.
The upper and lower fans were operated for 11 hours even after the rotor stopped.
It was cooling down.

However, in FIG. 2, N is the rotational speed of the rotor 3,
Q indicates the air volume of the fan, and T indicates the temperature of the bracket arm and anti-vibration stay.According to the experimental results, the operation of the upper fan has a large effect on the cooling of the bracket arm and anti-vibration stay, but the influence of the lower fan is Even if you stop the lower fan.

The temperature of the bracket arm and anti-vibration stay increases by only 3℃, and if the upper fan is operated for about 20% longer than before, the temperature of the bracket arm and anti-vibration stay will remain the same as before. found.

That is, in the present invention, as shown in FIG. 3, the lower fan stops near the rotor stop, and even after the rotor stops, only the upper fan continues to run at Δτ, which is about 20% longer than 4τ in FIG.
Make sure that the temperature of the bracket arm and vibration isolation stay does not become higher than the temperature during normal operation.

〔Effect of the invention〕

According to the present invention, the lower fan is stopped near the rotor stop and only the upper fan is operated for a slightly longer time than before, so when the capacities of the upper fan and lower fan are the same, the power consumption is 40% lower than before. It can be reduced by about %.

That is, p0=(pu +PL)xJτ...(1)P,=P
L, )(KW)Δτ
: Conventional fan operating time (hr) Aτl : Fan operating time of this proposal (=1.2X,ill
τ) (hr)

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view of a chamber-shaft rotating electric machine, Fig. 2 is an explanatory diagram showing the relationship between the operating status of a conventional fan and the temperature of the vibration isolation stay and bracket arm, and Fig. 3 is the operating status of the fan of the present invention. FIG. 3 is an explanatory diagram showing the relationship between the vibration isolating stay and the bracket arm temperature. 3... Rotor, 11... Upper fan, 12... Lower fan. Agent Patent Attorney Akio Takahashi / Notification 17 / #Ml

Claims (1)

[Claims] 1. In a device that cools a rotating electric machine by installing electric fans above and below the rotor, the lower electric fan is stopped near the rotor stop, and the upper electric fan is installed near the rotor. 1. A ventilation device for a room-shaft rotating electric machine, characterized in that the ventilation device is configured to stop after operating for a predetermined period of time after stopping.