Coursework Calculation of thermal power plant electrical equipment 380 MW

Contents

Contents

Task

Summary

Introduction

1 Selection of two structural diagrams

1.1 Structural diagram of the first version

1.2 Structural diagram of the second version

2 Main equipment selection

2.1 Selection of generators

2.2 Selection of block transformers

2.3 Selection of number and power of communication transformers

2.4 Capacity flow diagram

3 Calculation of the number of lines

3.1 Calculation of the number of lines for the first option

3.2 Calculation of the number of lines for the second option

4 Selection of switchgear diagrams

4.1 RUVN-110 kV

4.2 RUSN-35 kV

4.3 GRU-10 kV

5 Feasibility comparison of two options

6 Auxiliary diagram

7 Calculation of short-circuit currents

7.1 Design Diagram

7.2 Substitution Scheme

7.3 Resistance Calculation

7.4 Circuit conversion for K- point

7.5 Calculation of short-circuit currents for K- point

7.6 Circuit conversion for K- point

7.7 Circuit conversion for K- point

7.8 Circuit conversion for K- point

7.9 Circuit conversion for K- point

7.10 Circuit conversion for K- point

7.11 Results of short circuit currents calculations

8 Selection of switches and connectors

8.1 General conditions for selection of electrical devices

8.2 Selection of switches and disconnectors for RU-110 kV

8.3 Selection of switches and disconnectors for RU-35 kV

8.4 Selection of switches and disconnectors on GRU, 63 MW generator input circuit

8.5 Selection of switches and switchgear for outgoing lines with GRU

8.6 Selection of switches and switchgear for RUSN-6.3 kV

9 Selection of current and voltage measuring transformers

9.1 Selection of current transformers

9.2 Selection of voltage transformers

10 Selection of current-carrying parts

10.1 Selection of busbars and busbars on RU-110kV

10.2 Selection of busbars and busbars on RU-35kV

10.3 Selection of complete current conductor in generator circuit on GRU

10.4 Selection of the complete current conductor in the 220 MW unit generator circuit

10.5 Selection of prefabricated tires on GRU

11 Selection of overvoltage limiters

11.1 Selection of 110 kV overvoltage limiters

11.2 Selection of 35 kV overvoltage limiters

11.3 Selection of overvoltage limiters for 10 kV

12 Switchgear Design Selection

12.1 Open Switchgears

12.2 Design of GRU-

12.3 Package Switchgear Design

Conclusion

List of literature

Task

In this exchange rate project, we calculate and design a CHP of 380 MW.

Communication with the system is performed via 110 kV AC.

Issued from tires: Pmax35 = 32 MW; Pmax10 = 70 MW; Pmin10 = 0,8 * Pmax10

Power factor: = 0.87.

Maximum load usage time Tmax = 4300 hours.

Fuel - fuel oil.

Power system capacity is Sn c110 = 4500 MVA.

Resistance of a system Hn s110 = 0.8.

The length of the transmission line with the LLEP power system 110 = 25 km.

Consumer: Telephone plant.

Summary

In this course design, in accordance with the given task, the thermal power plant TETs380 MW was developed.

Two structural diagrams were selected, generators were selected, block transformers and communication transformers were calculated and selected.

The number of lines has been calculated. Switchgear diagrams selected. To identify the best option, a feasibility comparison was made between the two options.

The auxiliary power supply scheme has been developed. Short-circuit currents are calculated. Switches, disconnectors, current and voltage transformers are selected. Current-carrying parts and switchgear design were selected.

Introduction

Electricity in the developed countries of the world is the basic industry of the fuel and energy complex and determines the state of the economy. In addition to quantitative and structural changes in the electric power industry, one of the important trends is the integration of electric power systems (EES) and the formation of regional and interstate energy associations. The feasibility of integration is determined by the possibility of using system effects in the process of maneuvering with energy resources, generating capacities and electricity flows. The main purpose of the EES expansion and consolidation is to provide consumers throughout the territory with high-quality and high-reliability electricity interconnection and electricity services. Thus, the electricity industry is increasingly becoming a part of the infrastructure sector of the economy.

The main share in the structure of generating capacity is accounted for by thermal power plants powered by organic fuels, except in Latin America, where, due to natural conditions, hydropower has been prioritized

According to most forecasts, organic fuels will continue to play a leading role in the fuel mix of thermal power plants over the next few decades. The prerequisites for this are: a favorable price environment for organic fuel for consumers; good technical development of energy production technologies based on organic fuels; Significant explored reserves of oil, gas and coal and the gradual transfer to this category of part of their geological reserves.

In the last decade, the conditions for the development of the Russian electricity industry have changed. Changes affecting trends in generating capacity development include the following.

- Much more than before, attention to the environmental problems of the development of the electric power industry on the part of the population and public organizations.. Proper consideration of environmental factors when placing energy facilities in the regions limits the unit capacity of power plants, requires the separation of thermal power plants in a larger territory, a decrease in the volume of hydroelectric reservoirs, and increases interest in the use of small power plants, including on renewable energy resources.

- Crisis phenomena in power engineering and energy construction industry. The slow pace of commissioning of generating capacities in the last decade and, accordingly, small volumes of orders for energy equipment affected the state of these industries - qualified specialists left, large construction teams broke up, etc. Restoring the productive capacity of these industries, its modernization on a modern basis will require significant funds and time.

- Restructuring and modernization of the country's economy on a new basis with the active use of energy-saving technologies, which will lead in the future to a decrease in the growth rate of electricity demand. This is confirmed by the experience of developed foreign countries. This factor does not facilitate the introduction of large enough power plants.

- A significant increase in uncertainty in electricity demand in the future due to market uncertainty but compared to the planned economy. The effect of this factor requires a significant increase in the adaptability of the development of the electric power industry to changing conditions, which can actually be achieved by relatively small power plants built in a short time.

Thus, the new conditions for the development of the electric power industry in Russia lead to significant changes in the structure of generating capacities, their growth rates, and the placement of power plants.

Selection of two structural diagrams

Structural electrical diagram depends on the composition of equipment (number of generators, transformers), distribution of generators and load between distributors of different voltages and communication between these switchgears.

Since the designed CHP according to the assignment condition has 10 kV and 35 kV power consumers, it is necessary to have a 10kV generator voltage switchgear (GRU) and 35kV (RUSN).

For communication with the power system, a 110 kV high voltage switchgear is built.

We will draw up two structural schemes and conduct a technical and economic comparison of them, according to the results of which we will choose one scheme.

Switchgear Design Selection

According to PUE, at a voltage of 10 kV, closed switchgears are built at the station, at a voltage of 35 kV and above, open switchgears are built (RMS), provided that the station is not located in the chemically active zone or in the Far North region.

In this course design, RU110kV, RU-35kV open and RU10kV are closed, since the station is located near the chemical plant.

12.1 Open Switchgears

Switchgears shall ensure reliable operation of the electrical installation, which can be performed only with correct selection and arrangement of electrical equipment, with correct selection of RP type and design in accordance with PUE.

Service should be convenient and safe. Placement of equipment in the switchgear shall ensure good visibility, convenience of repair works, complete safety during repairs and inspections. For safety, minimum distances from current-carrying parts to various elements of the RAM are observed.

Non-insulated conductive parts shall be placed in chambers or enclosures to avoid accidental touching. The railings can be solid and mesh. In many structures of the RAM, a mixed fence is used - on the solid part of the fence the drives of switches and disconnectors are attached, and the mesh part of the fence allows you to monitor the equipment. The height of such a fence shall be at least 1.9 m. The fences shall be locked.

Uninsulated current-carrying parts located above the floor at a height of up to 2.5 m in 310kV and 2.7m in 2035kV installations shall be covered with a grid, the height of the passage under the grid shall be at least 1.9 m.

Rooms shall be provided with exits to the outside or to rooms with non-burning walls and slabs.

The RP shall ensure fire safety.

Switchgears shall be economical.

12.2 GRU-10kV design

Generator switchgear (GRU) 10 kV is made according to the scheme with one system of busbars divided into three sections and group twin reactors on the lines.

63MW generator is connected on each section of busbars. Auxiliary transformers are connected to the first and second sections. Standby MV transformer is connected to the third section.

A group twin reactor is installed on each section. The GRU building is one-story with a span of 18 m, made of standard reinforced concrete structures that are used for the construction and other buildings of thermal power plants. In the central part of the building, two rows are located blocks of busbars and bus disconnectors, followed by cells of generator, transformer and sectional switches, group and sectional reactors and bus voltage transformers. Cell spacing 3m. Complete switchgear cabinets are located near the building walls. All cables run in two cable tunnels.

Cooling air is supplied to the reactors from two ventilation channels, heated air is discharged outside through the exhaust shaft. Air is supplied to the channels by special fans installed in three chambers.

Equipment maintenance is carried out from three corridors: the central control corridor with a width of 2000 mm, the corridor along the KRU cabinets, designed for rolling out trolleys with a switch and the service corridor along a number of generator switches. All cells of generator switches are located on the side of the generator switchgear facing the turbine compartment, and cells of communication transformers are located on the side of the open switchgear. This arrangement makes it possible to connect generators and communication transformers to the cells of the generator switchgear using suspended flexible current wires.

12.3 Package Switchgear Design

KRU cabinets are manufactured at factories, which allows you to carefully assemble all units and ensure reliable operation of electrical equipment. Cabinets with fully assembled and ready for operation equipment come to the installation site, where they are installed, connect assembly buses at the joints of cabinets, supply power and control cables. The use of the switchgear makes it possible to speed up the installation of the switchgear. The switchgear is safe to maintain as all energized parts are covered by a metal casing .

Air, oil, pyralene, solid insulation, inert gases can be used as insulation between current-carrying parts in KRU. The switchgear cabinet with non-burning partitions is divided into compartments: switches on a retractable trolley; prefabricated tyres; linear input; relay cabinet. The design of the switchgear cabinets provides for the possibility of installing trolleys with a switch, voltage transformer or with disconnecting contacts with a jumper in the working, control position and rolling out of the cabinet for inspection and repair. Switchgear cabinets have locking devices that do not allow rolling or rolling out the trolley when the switch is on, as well as turning on the ground disconnector when the trolley is in working position and rolling the trolley when the ground disconnector is on.

KRU manufacturers in catalogs provide a grid of typical diagrams of the main circuits of cabinets, focusing on which the types of cabinets are selected and the switchgear of a specific electrical installation is equipped .

Conclusion

The CHP 380 MW was calculated according to the most economical version of the scheme. Modern generators with water and hydrogen cooling have been chosen. RP designs are adopted according to typical schemes, which are now widely used and have proven themselves. Modern switches, disconnectors, current and voltage transformers, as well as current-carrying parts were selected. When selecting equipment, the development and recommendations of design organizations for better electricity production were taken into account.

The choice of modern equipment increases the efficiency and reliability of the power plant, as well as improves the environmental performance of the electricity production process.

The graphic part shows the complete schematic diagram of the CHP 380 MW and the section of the bypass switch.