Steam turbine, Perm

Process Part

Purpose and description of sealing ring

Rear end seal is designed to prevent air suction into flow part. When air flows through the gap between the shaft and the scallop, it accelerates, then the kinetic energy of the flow c2/2 gets into the expansion chamber and passes into the thermal one. Passing through the next gap, the flow is again speeded so as to slow down in the next expansion chamber of the seal. Thus, the flow through the seals is reduced to sequentially alternating acceleration and quenching of the kinetic energy of the flow.

The sealing ring is a part that directly forms gaps and expansion chambers. Thus, ensuring the operation of the entire node. It is a ring with grooves threaded along the inner surface. The ring for assembly is supplied cut into 6 parts, and is installed in a special race. Holder has T-shaped slot for ring installation and consists of two halves. The holder itself is attached directly in the turbine housing.

The material is 15CM steel. Steel is designed for parts operating under pressure in a wide range of temper-tour.

Define Production Type

Since the O-rings for other turbines manufactured in the plant have a similar configuration and approximately the same size, small-scale production is adopted for the development of the technological part of the diploma project.

Part processability analysis.

The processability of the design is the degree of compliance with optimal production and production conditions at a given production scale.

The technological properties of the structure have a great influence on the entire production preparation process, as well as on the technical and economic indicators of production .

Constructability should always be considered as a complex concept, taking into account the requirements of all phases and stages of the process.

As mentioned above, forging is selected as the workpiece by means of which we form the shape of the part. Machining is required to obtain final dimensions.

Preliminary, rough turning is carried out then the part should be heat treated, then final processing takes place. The de-tal for installation in the node is cut into six segments.

The machining process includes 16 operations. Of these, the main are turning-carousel. vertical drilling and horizontal milling machines are also used

Description of the accessory.

Appliance for cutting consists of plate pos. 2, to which the housing pos. 3 freely moving along the trough on the plate. A stop is attached to the housing for dividing the ring by the required angular size. Two locating pins are installed in the body, which restrain the part from shifting into the direction of the cutting tool movement. A clamp is attached to the housing on the support and bolt, which keeps the part from shifting upwards.

On the machine table the accessory is installed on the keys, which attach the accessory on the machine.

The ring is inserted with a radial cut 4 mm thick into which the stop is inserted. The part must be installed until it rests on the locating pins and fixed from above with a grip. A cut is made, then the fixing bolt is loosened and the ring is turned until stop and fixed with a grip.

The main force from the cutting force is perceived by the setting fingers.

The takeover is designed to prevent accidental upmixing. Therefore, the fixing bolt is selected for design reasons.

The accessory is made of structural steel.

Research part.

Introduction

The study shall be carried out to determine the optimal parameters of overheating selection and overheating itself .

Tasks: Identification of the relationship between steam flow to the turbine head and heating steam pressure, steam overheating temperature, "return point" of heating steam condensate.

The criterion for the selection of optimal parameters is the flow rate to the head of the turbine (D) and the specific flow rate per 1 kWh (d), parameters that determine the efficiency of the power unit as a whole.

We calculate the schematic thermal diagram:

with overheating temperatures from 130◦S to 170 ◦S, with a step of 10◦S ;

with a heating steam extraction pressure of 4 MPa and 6.24 MPa;

With return of heating steam condensate to PVD5, PVD6 and deaerator ;

Conclusions.

During the research part, 22 options were calculated. The calculation showed that the option has the best economy: extraction of heating steam 4 MPa, overheating to 170◦S, condensate discharge point - deaerator. This option is accepted for design.

Conclusion

Thus, based on modern design methods and the modern state of science in the development of steam turbines, a 300 MW power turbine was designed with a reduced cost of 1 kW of installed power. The intermediate gas superheat is replaced with steam superheat, which reduces cost and increases reliability. This STP is designed to work on cheap coal, in places of direct fuel production. The calculation showed that the designed engine fully meets environmental requirements and standards.