CN2600590Y

CN2600590Y - Closed tube with bypass small butterfly valve device

Info

Publication number: CN2600590Y
Application number: CN 03211444
Authority: CN
Inventors: 何坚忍
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-02-18
Filing date: 2003-02-18
Publication date: 2004-01-21
Anticipated expiration: 2013-02-18

Abstract

The utility model relates to a communicating tube having a bypass small butterfly valve device, which comprises a communicating tube connected between a middle-pressure cylinder and a low-pressure cylinder. A controllable butterfly valve is arranged on the communicating tube. A bypass with smaller diameter than that of the communicating tube is arranged between the inlet and outlet of the controllable butterfly valve. A bypass small butterfly valve is arranged on the bypass. The device of the utility model is arranged between the middle-pressure cylinder and the low-pressure cylinder of a large power steam condensing type heating steam turbine unit. The utility model can control the heating and pumping quantity through the bypass small butterfly valve, the butterfly valve has no occurrence of vibration and serious noise, and the operation safety can be fully guaranteed. Meanwhile the utility model can further increase the heating and pumping quantity of the steam condensing heating steam turbine, and the thermal efficiency of the steam turbine can also be improved.

Description

Cross over pipe with bypass small butterfly valve device

(1), affiliated field

The utility model relates to a kind of cross over pipe.Specifically a kind of cross over pipe that is used for the intermediate pressure cylinder of high-power sucking condensing type heat supply steam turbine group to low pressure (LP) cylinder.

(2), background technique

Although the little steam turbine of heat supply has heat capacity, because of generating efficiency is low, its development is restricted.With high-power condensing steam turbine (more than the 100MW), at the intermediate pressure cylinder extraction for heat supply that burrows to the cross over pipe place of low pressure (LP) cylinder, butterfly valve is installed on cross over pipe, control heat supply rate of air sucked in required just makes to be the sucking condensing type heat supply steam turbine into.In the non-heat supply phase, the control butterfly valve on the cross over pipe is opened fully, and the valve on heat supply bleed steam pipework pipe is fully closed.Be condensing steam turbine still this moment then, has higher generating efficiency; In the heat supply phase, the valve open on the heat supply bleed steam pipework, and the control butterfly valve on the cross over pipe begins to cut out.After turning down the control butterfly valve, the steam flow that enters low pressure (LP) cylinder reduces, and reduces part steam by the outside heat supply of heat supply extraction steam pipe.Steam turbine is taked the electricity determining by heat method of operation like this.The external heat supply of not only can drawing gas, and each pressure level of steam turbine is still the same with the capable operating mode of pure condensate automotive before bleed steam pipework, and higher generating efficiency is arranged.Heating load is big more, and the thermal efficiency of steam turbine is just high more.Therefore this sucking condensing turbine generally is applied at home.

As previously mentioned, the heat supply amount of drawing gas is big more, and it is more little just to enter the low pressure (LP) cylinder steam flow, and the thermal efficiency of steam turbine is high more.But the steam flow that enters low pressure (LP) cylinder can not be less than so-called low pressure (LP) cylinder minimum discharge (being low pressure (LP) cylinder cooling flow).But the cross over pipe diameter of taking out unit with fixed attention in fact at present is very big, generally at Φ more than 900, so the bore of control butterfly valve is just very big.And the regulation range of butterfly valve is limited, and general aperture adjusting function in the time of 30 °～70 ° is better.For the amount of drawing gas is increased, reduce the into steam flow of low pressure (LP) cylinder, will turn down butterfly valve opening.When butterfly valve turn down 15 °～below 20 ° the time, not only the adjusting function of butterfly valve is bad, and because of butterfly valve is in little aperture state, this moment, vapor stream produced serious eddy current through the valve setting of butterfly valve, cause butterfly valve vibration and noise to strengthen, so that have influence on the security of operation of whole unit.So the aperture of butterfly valve remains on more than 25 ° usually.The increase of heat supply rate of air sucked in required so just is restricted.

(3), summary of the invention

The purpose of this utility model is to provide a kind of can making to enter the low pressure (LP) cylinder steam flow and further reduce, and reaches minimum discharge, makes butterfly valve that vibration and noise, the cross over pipe with bypass small butterfly valve device of security of operation do not take place again.

The purpose of this utility model is achieved in that it comprises and is connected in intermediate pressure cylinder to the cross over pipe between the low pressure (LP) cylinder, the control butterfly valve is installed on the cross over pipe, between the entrance and exit of control butterfly valve, be provided with the bypass of diameter, the bypass small butterfly valve is installed in the bypass less than cross over pipe.The diameter of bypass is 1/2～1/4 of a cross over pipe diameter, is generally 1/3.

Advantage of the present utility model is: device of the present utility model is installed in the intermediate pressure cylinder of high-power sucking condensing type heat supply steam turbine group between the low pressure (LP) cylinder, and the installation extraction steam pipe that burrows on the cross over pipe is installed the bleed steam pipework valve on the extraction steam pipe.In the non-heat supply phase, the control butterfly valve on the cross over pipe is opened fully, and the bleed steam pipework valve on extraction steam pipe pipe is fully closed.In the heat supply phase, the valve open on the extraction steam pipe, and the control butterfly valve on the cross over pipe begins to cut out.When the control butterfly valve is closed to 25 °, increase the heat supply rate of air sucked in required if desired again, just can will control the butterfly valve complete shut-down behind the standard-sized sheet bypass small butterfly valve, just carry out the transition to small butterfly valve control from big butterfly valve control.Continue to increase the heat supply rate of air sucked in required if desired, only need turn down the aperture of bypass small butterfly valve.When the heat supply amount of drawing gas reaches maximum, promptly advance the low pressure (LP) cylinder steam flow and be minimum (low pressure (LP) cylinder cooling flow), the aperture of bypass small butterfly valve also can reach 30 °～40 °, fully in the normal operation aperture scope of butterfly valve, butterfly valve can not vibrate and serious noise, and the unit operation Security can be guaranteed fully.Can make like this and take out with fixed attention that the heat supply rate of air sucked in required of heat supply steam turbine further increases, the thermal efficiency of steam turbine also can be improved simultaneously.

(4), description of drawings

Fig. 1 is a structural representation of the present utility model;

Fig. 2 is a mounting structure schematic representation of the present utility model;

Fig. 3 is the mounting structure schematic representation of background technique.

(5), specific embodiments

For example the utility model is done description in more detail below in conjunction with accompanying drawing:

In conjunction with Fig. 1 and Fig. 2, composition with cross over pipe of bypass small butterfly valve device comprises and is connected in intermediate pressure cylinder 1 to the cross over pipe 2 between the low pressure (LP) cylinder 3, control butterfly valve 4 is installed on the cross over pipe, between the entrance and exit of control butterfly valve, be provided with the bypass 9 of diameter less than cross over pipe, bypass small butterfly valve 8 is installed in the bypass, burrow on the cross over pipe extraction steam pipe 6 is installed, bleed steam pipework valve 5 is installed on the extraction steam pipe.The diameter of bypass is 1/2～1/4 of a cross over pipe diameter, is generally 1/3.

Claims

1, a kind of cross over pipe with bypass small butterfly valve device, it comprises and is connected in intermediate pressure cylinder to the cross over pipe between the low pressure (LP) cylinder, the control butterfly valve is installed on the cross over pipe, it is characterized in that: between the entrance and exit of control butterfly valve, be provided with the bypass of diameter, the bypass small butterfly valve is installed in the bypass less than cross over pipe.

2, the cross over pipe with bypass small butterfly valve device according to claim 1 is characterized in that: the diameter of bypass is 1/2～1/4 of a cross over pipe diameter.

3, according to claim 1,2 described cross over pipes with bypass small butterfly valve device, it is characterized in that: the diameter of bypass is 1/3 of a cross over pipe diameter.