JPH085286Y2 - High and medium pressure turbine cabin - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high and medium pressure turbine casing for a steam turbine.

[0002]

2. Description of the Related Art FIG. 2 shows the overall structure of a high and medium pressure turbine casing. In FIG. 2, steam supplied from a boiler (not shown) flows in from the main steam pipe 1, expands and works in the speed control stage 2 and the high pressure turbine stage 3. Then, the high-pressure exhaust steam is guided to the boiler from the high-pressure turbine outlet 4 through the high-pressure turbine outlet pipe 5.

Further, the steam reheated in the boiler flows in from the intermediate pressure turbine inlet pipe 6 and is expanded in the intermediate pressure turbine 7.
It does the work and exits the medium pressure turbine exhaust pipe 8 and is directed to a low pressure turbine not shown.

[0004]

In the high-intermediate-pressure turbine casing described above, conventionally, the high-pressure turbine exhaust chamber 9 and the outlet portion 11 of the high-pressure dummy 10 are divided into the high-pressure outer casing 12 and the high-pressure inner casing 13. As shown in FIG. 3, it is communicated with through a slit 14 which is provided between the openings and which is open in the entire circumferential direction.

Further, the space 15 surrounded by the turbine outer casing 12 and the turbine inner casing 13 is a large chamber and has a uniform pressure distribution in the circumferential direction, but in the high pressure turbine exhaust chamber 9, the high pressure turbine exhaust chamber 9 is exhausted. Due to the influence of the steam flow, the pressure distribution is different between the upper and lower passenger compartments. In FIG. 2, the pressure on the upper vehicle compartment side is higher than that on the lower vehicle compartment side. Therefore, the differential pressure of the slit 14 differs depending on the upper and lower vehicle compartments, the balance of the flow rate is different, and as a result, the temperature distribution between the upper vehicle compartment and the lower vehicle compartment is different.

If there is a temperature difference between the upper compartment and the lower compartment, the difference in thermal expansion causes the outer turbine compartment 12, the inner turbine compartment 13 and the like to be deformed. However, there were problems such as shaft vibration due to fin contact and performance deterioration due to excessive clearance.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and prevents the deformation of the vehicle interior due to the temperature difference between the upper vehicle compartment and the lower vehicle compartment in the high and medium pressure turbine vehicle compartment. The purpose is to prevent shaft vibration and performance deterioration.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a high and medium pressure turbine in which a high pressure turbine exhaust chamber and a space between the turbine inner and outer casings communicate with each other through a circumferential slit. In the passenger compartment, only the portion near the horizontal joint of the slit is opened, and the other remaining portions have a seal structure.

[0009]

According to the above means, since the slit has a structure in which only the portion near the horizontal joint is opened, the difference between the high pressure turbine exhaust chamber acting between the slits and the space between the turbine inner and outer casings. The pressures are equal and there is no difference between the upper and lower cabs. As a result, the flow rate through this slit is constant, and no imbalance occurs between the upper and lower vehicle compartments. When the flow rate becomes uniform, the temperature difference between the upper and lower cabs also disappears, and the temperature distribution becomes uniform, so that the deformation of the cab can be prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described in detail below with reference to FIG. FIG. 1 shows the structure of the present invention taken along the line AA of FIG. 2, and corresponds to FIG. 3 showing the conventional structure. Therefore, FIG. 2 is also referred to in the following description. .

In FIG. 2, above the high pressure turbine outlet 4,
Due to the pressure distribution between the lower vehicle compartments, the differential pressure in the slit 14 portion that passes through the high-pressure turbine exhaust chamber 9 and the space 15 between the turbine inner and outer vehicle compartments 13, 12 is different between the lower vehicle compartments, and the flow rate in the slit 14 portion is different. Is different. In some cases,
The direction of the slit flow also differs between the upper and lower passenger compartments.

Therefore, according to the present invention, as shown in FIG. 1, in the slit 14, only a portion near the horizontal joint having almost no pressure difference is opened as indicated by reference numeral 14a, and the other remaining slit portions are indicated by reference numeral 14b. As shown, it has a complete seal structure.

As described above, according to the present invention, since the effective slit portion 14a is provided in the horizontal joint portion, it is not affected by the pressure imbalance between the upper and lower vehicle compartments of the high pressure turbine exhaust chamber 9 and is effective. The differential pressure of the slit portion 14a is the same between the upper and lower vehicle compartments. As a result, the internal flow rate balance between the upper and lower passenger compartments is the same, and there is no temperature difference between the upper and lower passenger compartments.
No deformation of the passenger compartment occurs.

[0014]

As described above, according to the present invention, in the high and medium pressure turbine casing in which the high pressure turbine exhaust chamber and the space between the turbine inner and outer casings communicate with each other through the circumferential slit, Only the part near the horizontal joint of the slit is opened, and the remaining part has a seal structure to make the flow rate between the upper and lower passenger compartments uniform and to eliminate the temperature difference, thus preventing deformation of the passenger compartment. In this way, the clearances of the respective parts of the turbine can be properly maintained, the shaft vibration due to the contact of the fins and the deterioration of the performance due to the excessive clearance can be prevented, and the reliability can be improved.

[Brief description of drawings]

1 is a cross-sectional view taken along line AA of FIG. 2 showing an example of a high-intermediate-pressure turbine casing according to the present invention.

FIG. 2 is a cross-sectional view showing the overall structure of a high / middle pressure turbine casing.

FIG. 3 is a cross-sectional view showing a conventional high-intermediate-pressure turbine casing along the line AA of FIG.

[Explanation of symbols]

 9 High-pressure turbine exhaust chamber 12 Turbine outer casing 13 Turbine inner casing 14 Slit 14a Opening 14b Seal portion 15 Space between inner and outer casing

Claims (1)

[Scope of utility model registration request] 1. A high-intermediate-pressure turbine casing in which a high-pressure turbine exhaust chamber and a space between the turbine inner and outer casings communicate with each other through a slit in the circumferential direction, and only a portion near the horizontal joint of the slit is opened. A high-to-medium-pressure turbine casing characterized by having the rest of the structure sealed.